This PDF file contains the front matter associated with SPIE Proceedings Volume 11767 including the Title Page, Copyright information, and Table of Contents.

As a kind of main homogenizing device, the homogenizing rod is widely used in laser lighting system. ZEMAX software is used to simulate the light path when the length, tilt degree and aperture size of the homogenizing rod change, and the uniformity of the light spot is calculated by ZPL language in ZEMAX software. The results show that the longer the rod length is, the better the effect is. When the length reaches a certain value, the uniform effect remains unchanged; when the inclination angle is about 0.75 ° and the aperture size exceeds the light source ratio of about 250%, the effect is better Good, the conclusion provides the basis for the selection of the uniform rod in the laser lighting system.

Using laser as a technology of wireless energy transmission to supplement power for small electronic equipment, for the characteristics of fast charging speed, flexible and convenient implementation. The wireless energy transmission system consists of mobile charging station and mobile object. There are two-dimensional platform, laser and corresponding optical elements on the mobile charging station. The platform controls the laser beam to aim at the photovoltaic panel located in the mobile object. The mobile object is designed using Super-Capacitor to store electricity generated by photovoltaic panels. Grid charging working area, modeling for moving objects. The logic algorithm of mobile charging station to mobile object charging is designed to deal with the general working conditions and special conditions. The experiment obtained the I-V curve of the photovoltaic panel illuminated by the laser, calculated and selected the SuperCapacitor to meet the car's electricity demand. The results show that the wireless energy transmission using laser technology can realize the long distance transmission of the electrical energy required by small electronic equipment and fit the requirements of long time continuous operation.

This article designs a vehicle-mounted inverter power supply with TMS320F28335 as the main control chip, which converts 12V DC voltage to 220V/50Hz AC voltage. The system uses a two-stage conversion circuit structure, including a front-stage DC-DC push-pull boost circuit and a back-stage DC-AC full-bridge inverter circuit. The front stage pushpull selects the SG3525 chip as the main control chip of the push-pull circuit, which uses voltage closed-loop control; the rear-stage DC-AC inverter circuit adopts a dual closed-loop PI control strategy of output voltage outer loop and current inner loop. Finally, a 500W experimental prototype was built and various performance index tests were carried out. The test results show that the design in this paper. The indicators of the on-board inverter power supply meet the design requirements.

The acoustic absorption performance of ultra-thin metal micro-perforated panels (Mpp) with different thicknesses backed by an air cavity is studied in this paper. The ultra-thin metal Mpp with different structural parameters are processed by the computer numerical control machine tool and tested in the impedance tube. The experimental results show that the acoustic absorption performance of the ultra-thin metal Mpp absorber cannot be predicted directly by the sound absorption theory of rigid Mpp. It can be concluded that the vibration of the ultra-thin metal Mpp cannot be ignored. In addition, the acoustic absorption performance can be further optimized by rationally designing structural parameters and coupling with the vibration of the ultra-thin metal Mpp.

In order to ensure the detection accuracy of laser-induced fluorescence detection, the micro droplet digital PCR material was required to have weak autofluorescence. The autofluorescence characteristic of micro droplet digital PCR chip was studied in this paper. Firstly, the chip was designed according to the principle of micro droplet digital PCR. Cycloolefin copolymers (COP) and cycloolefin polymers (COP) in organic polymers were selected as the materials of the chip because of their excellent biological characteristics. The laser induced fluorescence device was build. The excitation laser wavelength were FAM (Emission band:522nm, Excitation band:470nm) and HEX (Emission band:553nm, Excitation band:530nm) respectively. The fluorescence image of chip under different exposure time and different band was extracted by COMS camera. And read the fluorescence value through the computer software ImageJ. The glass plate was used as the reference for autofluorescence measurement of chip. From the test results, COC chip showed a good autofluorescence property compared with COP chip, which has lower autofluorescence value under laser excitation. Therefore, for the quantitative detection of trace nucleic acid, the high fluorescent background noise of COP chip will increase the threshold of negative positive discrimination which cloud lead to discrimination error and influence the requirements of detection accuracy. The research results provide a basis for the selection of high-precision micro droplet digital PCR chip materials.

In order to enhance the absorption of phase change materials in specific spectral range, a novel compact structure based on surface plasmon resonance is proposed, which is composed of vanadium dioxide (VO₂) film and Au-disk structure. Simulation results show that the absorption peak at λ=4.0μm with the full width at half maximum is only about 100nm, and the dependence on the structure parameters are analyzed in detail. Because the resistivity changes greatly during the phase transition of VO₂, the detection of a specific spectrum can be completed by signal detection. Our study can be used in the development of new mid-infrared thermal detectors and active control devices.

We propose and design aluminum nitride slot waveguides with acoustic pumping to achieve large forward stimulated Brillouin scattering. The slot structure can constructively add to or destructively interfere with optical forces. The novel arrangement of symmetric electrodes can provide out-of-plane electric fields for piezoelectric materials and excite acoustic waves that satisfying the necessary phase-matching. In this work, the pump photons is intramode scattered into an anti-Stokes sideband by injected phonons. Our aluminum nitride slot waveguide is partly suspended on the silica glass to avoid the leakage of acoustic wave. The height of this waveguide is set to 500 μm and the gap is set to 50 μm. The distance between the electrode and the waveguide is flexible to adjust the piezomechanical coupling strength. Our proposed scheme offers an effective approach to implement acousto-optic interaction in integrated silicon photonics.

Brillouin lasing featured by narrow linewidth and wide tunability has been applied to sensing, coherent communication and microwave photonics. Here, we demonstrate a cascaded Brillouin lasing in the integrated silicon racetrack microring pumped by the external fiber loop. The elaborate micro-ring can tightly confine both optical and acoustic fields, and enable the efficient generation of cascaded forward stimulated Brillouin scattering. Under the high external pump power, we observe the cascaded Brillouin lasing up to 3 Stokes order and 3 anti-Stokes order. Our experiment provides a new method to realize a cascaded Brillouin lasing in on-chip platform.

The mechanical load of wind turbine is complicated and changeable under the imbalanced fault of wind wheel, which intensifies the influence of fatigue load on the service life of main components and the generation quality of wind turbine. The mechanism model of imbalanced load change of wind turbine is established. Aiming at the imbalanced load of wind turbine caused by two phenomena of wind turbine mass imbalance and aerodynamic imbalance, the time domain characteristics of mechanical load change on the top of tower drum are analyzed by GH Bladed wind turbine load simulation software to identify the change of characteristic parameters. The simulation results show that the two cases of imbalanced wind turbine will lead to the increase of fatigue load and limit load of wind turbine, which will destroy the stability of wind turbine. There are some differences in fault phenomena. The research results can provide basis for reverse reasoning and location of imbalanced wind turbine fault.

Photoluminescence of GaAs nanowires with and without AlGaAs Shell were analyzed detailly through temperature- and power-dependent photoluminescence spectroscopy. AlGaAs shell effectively eliminated the surface dangling bonds and defects caused by oxidation of GaAs surface. And a model of sub-bandgap absorption based on inhomogeneities in GaAs bandgap were applied to analyzed the “high energy tail” of GaAs nanowires with AlGaAs shell.

By combining Kirchhoff approximation (KA) with the method of moment (MOM), a hybrid method is proposed to solve the scattering problem of a dielectric target above a dielectric rough surface. The field on the rough surface can be represented by the tapered incident wave and the scattering field of the target as the secondary incident wave using Kirchhoff approximation. Then, the electric field integral equations of the induced current and magnetic current on the target are derived to solve the problem. The field of the rough surface can be directly obtained by the tapered incident wave and the current and magnetic current on the target surface. Therefore, compared with the traditional method of moments, the hybrid algorithm only needs to solve the electric field integral equation of the target. The simulation of bistatic scattering from a cylindrical target on a Gaussian rough surface is carried out, and the effectiveness and effectiveness of the method are verified.

In order to test the performance of the narrow pulse laser fuze detection system, static and dynamic tests were carried out on the laser fuze detection system. Through the static test, the maximum detection distance of the fuze was tested and the shock resistance test was carried out with the Machete hammer. The detonation position of the flying fuze was also recorded by high-speed camera. Static and dynamic tests show that: the detection system can detect aluminum plates with a maximum range of 74m and black objects with a maximum range of at least 22m. In terms of impact resistance, the laser fuze can withstand an impact force of at least 9600g and can be detonated at a predetermined distance as expected.

In this paper, the circuit design of 1470nm pumped laser required by fiber Raman amplifier is carried out, which solves the problem that the output optical power and wavelength of the laser are easily affected by temperature and drive current fluctuations. Compared with the existing circuit design, the circuit design in this paper simplifies the circuit topology structure, reduces the cost, ensures the working stability, and broadens the working linear area of constant current source. The current 1A is continuously adjustable, and the maximum relative error of current in one hour is 0.03% at 25°C. A chipset MAX1978 is adopted to realize temperature control, and the temperature control precision reaches 0.01°C. Finally, a high-precision semiconductor laser driving system with power supply of 5V and driving current of 1A is realized.

Volt-ampere nonlinearity is the origin of passive intermodulation, which means electric field-magnetic field nonlinear behavior of device or structure. Although DC nonlinear measurement is easier, it is not applicable to microwave frequency bands. This paper proposes a method to calculate the non-linear parameters of passive intermodulation—a non-linear parameter calculation method based on multi-state measurement. It is a universal method to measure nonlinear characteristic parameters of passive intermodulation. Then, we measure and calculate the non-linear parameters of passive intermodulation by the undetermined coefficients method and derive the third-order passive intermodulation expression.

Retroreflective sheeting dramatically increases the visibility and conspicuity of traffic safety facilities at night. Chromaticity is an important property of retroreflective sheeting, but there are few methods and tools for measuring retroreflected chromaticity coordinates of retroreflective sheeting in China. In this paper, measurement methods are introduced and the accuracy of portable equipment is analyzed. A spectroradiometric retroreflectometer system of the National Center of Metrization for Equipments of Roads and Bridges (NCMERB) and various portable equipment of testing agencies were selected. All instruments measured the chromaticity coordinates of the same set of samples. The data of the spectroradiometric retroreflectometer system were taken as the reference values and those of portable equipment as the comparison values. The results showed that the measurement deviations of a RoadVista 932 retroreflectometer were relatively small and that it can measure retroreflected chromaticity coordinates of retroreflective sheeting. The illuminating-viewing conditions may have little effect on the retroreflected chromaticity coordinate measurement results of yellow and red retroreflective sheeting.

A solid-state capacitor aluminum/carbon composite negative foil with the carbon layer weight less than 3 mg/cm2 and carbon/aluminum layer featuring with good interface adhesion and high specific capacitance is prepared by adding the pressing-in technique and the sol-gel idea based on the carbon coating technology on the paste. The microstructure and phase composition of the surface and interface of the aluminum/carbon composite foil are investigated by means of scanning electron microscope (SEM), and the effects of various composite carbon materials on the specific capacity of the negative electrode foil at different frequencies are discussed. The curve of the specific capacity of the negative electrode carbon foil with frequency is presented under the condition of different carbon slurry ratios. The results show that the pores on the surface of the carbon layer are developed, and the carbon layer and aluminum foils are closely combined, generating Al₄C₃ on the surface and forming a good metallurgical combination. When the ratio of full-carbon paste is 15:2:1:2, the combination of carbon/aluminum layer is greatly bonded and the specific volume is up to 2950x10^-6 F/cm² under the condition of 1kHz-0.3V. As the test frequency increases, the specific capacity attenuation is small.

Helically twisted long-period fiber gratings (H-LPFG) of the single-mode fiber provided by Yofc inc is spiral processed by commercial welding machine. There is an obvious second-order resonant dip near 1526 nm coupling between the fundamental mode and the LP₁₅ cladding mode when the pitch length is about 757 μm. The half peak width is about 15 nm, and the resonant dip is about -28 dB. The transmission intensity ratio of 10lg(I_1523.4nm/_I1537nm) and 10lg(I_1523.4nm/_I1551.1nm) versus temperature are measured, which show linearly with temperature. The radio sensitivity of I_1523.4nm/I_1537nm is about 0.023/C° compared with the wavelength sensitivity of about 45 pm/C°. This can be applied in temperature sensor.

With the increasing integration and transmission rate of vehicle-mounted video processing systems, the defects of electrical signal transmission attenuation, short transmission distance, and poor anti-interference ability become more and more obvious. Using optical transmission can effectively avoid the above problems. In this paper, combining optimization and testing of military vehicle-mounted optical transmission waveguides, a highly reliable military vehicle-mounted optical transmission beam expanding optical fiber transmission scheme was studied.

In order to explore the dynamic behavior and motion law of motorized spindle under eccentric condition, a dynamic model of motorized spindle considering unbalanced magnetic pull under eccentric condition is established. The effect of gyroscopic moment is considered. The model is established by Lagrange method, and the model is simulated and analyzed. The law of rotor response change under different speed, unbalance and air gap changes is obtained. The simulation results show that the static eccentricity will increase the vibration of the motorized spindle. Under the same static eccentricity and mass eccentricity, the influence of static eccentricity on rotor decreases with the increase of rotating speed. Mass eccentricity is called the main influencing factor. In frequency domain analysis, when the static eccentricity occurs, the peak appears at 0Hz, which is the effect of unbalanced magnetic tension on vibration. With the increase of rotating speed, the frequency size of the peak value of fundamental frequency will also increase. The research results provide a theoretical basis for the in-depth analysis of the failure mechanism of rotating machinery.

The electronic structures including energy band structure, total density of states (TDOS) and projected density of states (PDOS) of In/N codoping anatase TiO₂ were investigated by using first-principles. The theoretical calculation showed that In 5s and 5p states are well hybridize with N 2p state, which narrows the band gap considerably and make the valence band broader. Wide valence band could accelerate the mobile of the photo-generated holes. The significantly narrowed band gap and excellent mobility of the photo-generated holes can explain the obvious red shift of the absorption and strong absorption in the visible region observed in experiment.

In view of the short transmission distance, small coverage, poor penetration, and poor data transmission stability of the current instrument system, this paper proposes a design scheme for a multi-instrument remote wireless acquisition system based on narrowband Internet of Things. In terms of hardware, it mainly includes STM32 main control module, acquisition module, BC95 wireless communication module and power supply module, etc.; software mainly includes BC95 module communication module and concentrator main control module. The collected multi-meter data is sent to the upper management system using narrowband Internet of Things communication technology to realize remote data reading of multiple meters. Through experiments, the influencing factors of the upload rate of the wireless water meter collection system are studied, and it is verified that the upload rate of the wireless collection system designed in this paper meets the usage requirements.

The deep-sea hydrothermal velocity measurement system based on laser Doppler is mainly used for in-situ accurate measurement of deep-sea hydrothermal velocity. Due to the high-pressure environment of the deep-sea hydrothermal area, the optical window of the measurement system will be deformed under pressure, attenuating the energy of the scattered light received by the system. The system selects sapphire as the compressive window material, uses finite element analysis to simulate the compressive deformation of the optical window at a sea depth of 4000 meters (40MPa), and fits the deformed optical window to the optical design software. The simulation result shows the deep-sea high pressure will reduce the energy utilization rate of the measurement system by 43%. Through the optimized design of the optical system, the laser intensity utilization rate has been increased by 52.2% to meet actual application requirements.

The accelerometer servo circuit is one of the important components in the inertial measurement system. Based on the working principle of the quartz flexible accelerometer and the composition of the hybrid integrated quartz flexible accelerometer servo circuit, this paper developed a quartz flexible accelerometer servo circuit with low power consumption and high integration using a linear stabilized power supply servo transconductance/compensation amplifier. The development of this circuit has guiding significance for the development of the traditional quartz flexible accelerometer servo circuit.

Through the dispersion performance, surface tension, and concrete performance test of a single shrinkage reduction component, two kinds of shrinkage reduction components with better shrinkage performance were selected for compounding in different proportions to prepare a concrete composite shrinkage reducer P-3. The performance test results show that, the shrinkage reducing agent P-3 can greatly reduce the surface tension of the aqueous solution and has a good shrinkage reduction effect on concrete. When the mixing amount was 0.5%, the 7d concrete shrinkage rate reached 37%, and the 28d shrinkage rate was 35%. The effect of the shrinkage reducing agent on cement slurry hydration was studied by microcalorimeter, and then the mechanism of the shrinkage reducing agent was studied.

With the increasing demand of space optical imaging system for detecting dim targets, the level of stray light suppression limits the further improvement of detection performance of the optical system. In this paper, PST (Point Source Transmittance) method is used to build a set of large aperture and high precision measuring device. The device adopts visible light and near-infrared light sources. Collimation is carried out through the parallel light tubes and irradiation is carried out on the calibration lens in the double cylindrical chamber. The irradiance of the measured system under different off-axis angles (±5°-±60°) is measured. The measured value curve of PST was drawn and compared with the designed value curve, which are basically consistent. Furthermore, the measurement range of the system reaches 10^-3-10^-10 , which meets the engineering needs of stray light measurement of space optical system.

In power system, the problem of power quality will directly affect the fundamental interests of power generation, supply and use. The operation quality of overhead transmission lines is closely related to the level of power system. The safety and stability performance of the whole system will greatly improve if the discharge phenomenon can be judged by the online monitoring device. Therefore, it is of great importance to effectively investigate the discharge phenomenon of overhead transmission lines. The discharge of overhead lines is mainly corona discharge, which is usually presented as an electromagnetic pulse signal. Hence, the corona discharge signal has a wide band range, which is often accompanied by power loss, wireless interference and noise pollution. Detecting corona discharges can reflect line operation and provide reference information for maintenance. In this paper, the influence of different factors on the Hilbert fractal antenna is compared in the corona discharge detection frequency band of 200-300MHz. The influencing factors involved are order, feeding point position, wire length and wire width. By simulating the control variables, the optimal results are selected to optimize the final model parameters.

This paper mainly discusses that it is possible to directly determine whether the seismic instrument has a fault during operation based on characteristics of the waveform and that the specific fault of the instrument in such cases can be deduced in reverse according to different waveforms shown by different faults. Faults can be identified early through application of the reverse deduction to instrument maintenance, and maintenance personnel can be prompted to deal with them, thereby ensuring and improving data quality.

We demonstrate a high-power, wavelength tunable mid-infrared laser with a high-precision power attenuator. The output power is 5.1W at 3.8μm, achieved by an optical parametric oscillator (OPO) based on multichannel periodically-poled lithium niobate (PPLN). The repetition frequency is 10kHz, and the pulse width is 69ns. The wavelength is tunable from 3.708μm to 4.142μm. High-precision control on the power attenuator is obtained, the accuracy of the attenuator is 0.2dB from 0~27dB.

This paper presents a dual-frequency low profile horizontally polarized omnidirectional antenna for WLAN application. The purposed antenna produces horizontally polarized electromagnetic wave at two different frequency caused by multiloop resonance on its wing structures. To prove the validation of the purposed antenna, the measured return losses are 22dB and 35dB at 2.45GHz and 5.5GHz, respectively. The measured VSWRs at these two frequencies are less than 2 and the ovality of omnidirectional radiation patterns is less than 1.8dB. The purposed antenna is achieved for WLAN applications and dual-band MIMO systems.

When the pulsed laser proximity fuze works in a strong electromagnetic environment, strong electromagnetic pulses will be coupled from the optical window of the receiving system into the cavity and cause serious interference to the circuit system, resulting in inaccurate detection range, misfires and even early explosions. By studying the relationship between light transmittance and shielding efficiency of metal grating films with different periods and line widths, a metal grating film with appropriate periods and line widths is selected to shield the optical window. The CST software was used to establish an integrated shielding model loaded with metal grid light windows. The simulation results showed that the electromagnetic shielding performance reached 40dB in the 0-8GHz frequency band, while meeting the shielding performance requirements of the detection target.

Poly (3, 4- ethylenedioxythiophene) (PEDOT), as a conductive polymeric material, has been widely used in electrical materials, such as batteries and capacitors. The utility model has the advantages of high conductivity, easy processing, low cost, flexibility and good transmittance. In this paper, the common synthesis methods of PEDOT are briefly summarized, and the applications of PEDOT and PEDOT: PSS modified materials in solar cells and capacitors are reviewed.

In this paper, we demonstrate an improved dynamic demodulation system for acoustic sensors based on distributed feedback-fiber laser (DFB-FL). The signal is demodulated using the phase-generated carrier (PGC) demodulation technology based on unbalanced Michelson interferometer (MI). An improved PGC demodulation algorithm is introduced, which solves the problems of light intensity disturbance (LID) and phase modulation depth drift in the traditional PGC demodulation algorithm that affect the demodulation results. The acoustic pressure sensitivity test of a packaged DFB-FL acoustic sensor is carried out to evaluate the performances of the demodulation system, a flat acoustic pressure sensitivity and frequency response curve was achieved in the frequency range of 200 Hz~18 kHz, the wavelength-acoustic sensitivity was about -40.22 dB re. pm/Pa. The amplitude changes of demodulation signal with light intensity and modulation depth are also tested, and it shows that the stability of the demodulation system has been significantly improved.

A hydrogen and humidity simultaneous measurement system based on an integrated FBG sensor is proposed. Experimentally results indicate the sensor shows a high degree of hydrogen discrimination ranging from 100ppm-8000ppm and a high degree of humidity discrimination ranging from 20% - 80%, along with the high performance of anti-mutual interference of hydrogen and humidity.

Regular change of transmission lubricating oil is an important part of transmission maintenance, improving the service life of transmission lubricating oil is the focus of each manufacturer. Based on the analysis of lubricating oil components, this part develops a 100,000km maintenance-free transmission lubricating oil, and verifies its performance through specific experiments, proving that the new formula lubricating oil can meet the requirements of 100,000km maintenance-free. It provides the basis for the development of transmission oil in automobile enterprises.

This paper focuses on the error of measuring underwater vehicle radiation noise by using a single vector hydrophone based on the waveguide environment. Firstly, the underwater vehicle and ocean waveguide environment are simulated, and then, the effects of receiving distance, sound source depth and water depth on the measurement results are studied separately based on the waveguide environment. Studies have shown that when the underwater vehicle and measuring equipment are at different distances, the sound source level error will be within 1.5dB by using a single vector hydrophone to measure the noise of underwater vehicle in the simulated measurement environment; when the underwater vehicle is located at the different depths of water, the sound source level of the wideband signal radiated by underwater vehicle is quite different; when the range of water depth from 100m to 800m, the sound source level error measured by single vector hydrophone is less than 1dB.

The motorized spindle generates heat during high-speed operation, and the thermal deformation caused by temperature rise will seriously affect the machining accuracy of the motorized spindle. Therefore, in order to reduce the influence of the heating of the motorized spindle on the machining performance, the temperature field distribution of the motorized spindle is analyzed. Taking the motorized 170SD30 spindle as the research object, the temperature field of the motorized spindle was simulated by COMSOL software. The motorized spindle automatic test system was used to carry out the spindle cooling test. The motorized spindle cooling experiment showed the temperature distribution of the spindle in three common speed states. The higher the spindle speed runs, the higher the temperature of the spindle is; the higher the temperature of the cooling water is, the higher the temperature of the spindle is. The higher the flow rate of the cooling water is, the lower the spindle temperature is.

The paper uses secondary research to investigate various constructs and functional structures of GaN as a thirdgeneration semiconductor. A brief history of semiconductors is provided in terms of the generations that they occur. GaN was introduced in the 1990s, but its utility evolved until the 21st century. At the advent of its invention, Silicon (Si) and germanium (Ge) had been the most commonly used semiconductors. GaN presented unique advantages ranging from cost to size and utility. This was the frontier of new applications of semiconductors. The largest applications of GaN have been in LEDs, transducers, and transistors. GaN also has its limitations, which include its generally immobile energy band, and its substrate incompatibility. The future of GaN can be projected by factoring three main variables. These are cost, application/utility, and limitations.

The flapping-wing flying principle and actuator of a bird-like flapping-wing flying robot are studied. On this basis, a three-dimensional model of the seagull flapping-wing flying robot with double crank and rocker mechanism as the actuator is established, and the actuator is simulated and optimized in ADAMS software. The analysis results are consistent with the model and meet the design requirements. This paper provides a reliable reference and guidance for the theoretical research and practical model establishment of the flapping-wing flying robot.

The transmission of signal light and the noise accumulation in the fiber Raman amplifier (FRA) under 4-wavelength timedivision multiplexing (TDM) pumping is studied. The power variation of signal light has a certain periodicity which is related to the period of pumping. The shorter the pumping period is, the weaker the signal fluctuation is. Through the analysis of noise, it is found that amplified spontaneous emission (ASE) is the main source of the noise of FRA with TDMpumping. By comparing the TDM pump scheme with the continuous multi-wavelength pump scheme, it is found that the gain of the TDM pump scheme is higher than that of the continuous multi-wavelength pump scheme.

We propose and analyze the Ge/SGe coupled quantum wells (CQWs) with uniaxial tensile strain. A suspended micro bridge structure is employed to introduce the uniaxial tensile strain and the value of tensile strain can be tuned through the size and shape of the suspended region. The band dispersion and absorption spectrum of the strained Ge/SiGe CQWs are calculated for both TE and TM polarizations by an 8 band kp model. By introducing 1% uniaxial tensile strain, the absorption band edge has a prominent red shift more than 100nm for both TE and TM polarizations. Under the influence of uniaxial tensile strain, the absorption of TE polarization is enhanced while the absorption of TM polarization is receded. The proposed uniaxially tensile srained Ge/SiGe CQWs scheme paves the way to efficient silicon based integrated devices.

Aero-electromagnetic (AEM) is a geophysical exploration technology that uses aircraft platform to carry electromagnetic exploration equipment, which has the advantages of wide detection range, high efficiency and economy. In this paper, the design and modal analysis of the main circuit topologies, such as the aviation electromagnetic multi-pulse transmitting circuit with large magnetic moment and the phase-shifting full-bridge soft switching circuit, are carried out to improve the power density and transmitting power of the transmitting system, realize the multi-pulse transmitting with large magnetic moment, and effectively improve the detection depth and accuracy.

Equalizers are common microwave devices often used to improve the problem of unsatisfactory signal amplitudefrequency characteristics in microwave systems. This paper briefly introduces the basic principles of the equalizer, and brings up the equalizer designing method: based on the uneven signal amplitude-frequency characteristics, use the theoretical analysis to design the initial value, and perform computer simulation optimization, and develop the X-band microstrip equalizer. The test results show that the equalizer's equalization in the working frequency band is about 4dB, and the input and output standing wave coefficient is less than 1.5, which meets the system's designing requirements for equalization, standing waves and miniaturization.

Depending on the retroreflective distribution measuring device, three sets of controlled experiments were designed. To obtain the retroreflective distribution of road traffic markings, the coefficient of retroreflected luminance (RL) changes of road traffic markings under different measurement geometry was analyzed. Several observation angles commonly used in retroreflection measurements were selected. The deviation range of vertical entrance angles was set to 8°. The horizontal entrance angles were selected according to the horizontal measurement angle of a mobile retroreflectometer unit. A white road traffic marking sample, which measured 10 mm × 46 mm, was used in the experiments. The results showed that the retroreflective distribution of road traffic markings was not uniform, the influence of the change of observation angle on the RL was greater than the entrance angle, and the change of retroreflection in the direction of the vertical entrance angle was more obvious than the horizontal entrance angle.

Rail transit has become an indispensable part of urban development, but the rail corrugation in the process of vehicle running seriously affects the smooth and safe operation of vehicles. The rail grinding car can significantly reduce the impact of corrugation. The existing rail grinding equipment is heavy and not light enough. This paper mainly analyzes the design structure of the rail grinding unit based on statics, and optimizes the weight reduction of the connecting linkage.

With the improvement of computer level, the automation level of various large-scale equipment is gradually improved, which will strengthen the requirements of large-scale equipment for control system. However, the computer control system is inseparable from the application and control of various sensors, which is also an important embodiment of the current high automation of large equipment. Therefore, sensor network has become the bridge of large-scale equipment control system, which will directly reflect the state of equipment and effectively control the implementation of the working process. Therefore, accurate analysis and evaluation of sensor status information has become an indispensable part of large-scale automation equipment, which will directly affect the safe operation of control system and equipment. Therefore, it is necessary to diagnose the faults of multiple sensors. Multi-dimensional Information Fusion (hereinafter referred to as MDIF) technology is a simultaneous interpreting method of different sensor data by computer technology, which can accurately acquire information of multiple sensors. Through analysis and decision-making, we can better control and monitor large-scale equipment. Therefore, MDIF has been applied to large-scale equipment detection and fault diagnosis. Based on computer control technology, multi-dimensional fusion of multi-sensor information is realized in this paper. Finally, based on the powerful computing power of computer, this paper puts forward the analysis method of neural network control.

Volt-ampere nonlinearity is the origin of passive intermodulation, which means electric field-magnetic field nonlinear behavior of device or structure. Although DC nonlinear measurement is easier, it is not applicable to microwave frequency bands. This paper proposes a method to calculate the non-linear parameters of passive intermodulation, a non-linear parameter calculation method based on multi-state measurement. It is a universal method to measure nonlinear characteristic parameters of passive intermodulation. Then, we measure and calculate the non-linear parameters of passive intermodulation by the undetermined coefficients method and derive the third-order passive intermodulation expression.

In the fields of electrical, automation, power transmission and transformation engineering, rail transit, aerospace and other fields, the connection of wires and cables is an important link in the safe operation of electrical lines and the whole system, and the demand for lightweight connection technology is more urgent. Traditional wire and cable connection, this way is not difficult to cause cable joints loose, corrosion and aging phenomenon, there are many potential hazards. Therefore, enhancing the connection method of wire and cable joint and improving the processing quality and reliability of cable joint is essential measures for the technological progress of various enterprises related to wire and cable. In this paper, the principle, characteristics, realization process, forming condition and quality effect of the welding joint are dealt within detail. The experimental results show that the welding effect is very good, the dissimilar materials are closely linked without gap, the welding process takes a very short time, there is no smoke, gas generation, green environmental protection.

The detection of microorganisms like bacteria in water is extremely important and challenging. Colony detection is an effective solution because visible colonies can be formed by bacteria in water. Aiming at the characteristics of small targets and regular shape in RGB image, a cascade network combining SSD_MOBILENET_V1_FPN with SVM HOG classifier is designed to detect and count the colonies with high accuracy, both error rate and missing rate were less than 3%. To solve the performance bottleneck, a on-chip system device Zynq UltraScale+ MPSoC EV is applied to accelerate colony count cascade network based on FPGA which could support AI computing acceleration, it can detect and count 10 colony images per second with the advantage of portability and low power consumption.

X-ray digital imaging (DR) equipment is used for accurate detection, but its own assembly defects will affect the equipment detection results. Therefore, an accurate detection method is needed to detect Dr equipment assembly defects. Because the parameters set by the traditional method can not control the noise interference to the minimum, resulting in poor detection results. Therefore, an intelligent detection method of DR equipment assembly defects based on X-ray digital imaging is proposed. This method obtains the factors affecting the X-ray digital imaging, sets the imaging detection parameters, and detects the DR equipment assembly defects based on the X-ray digital imaging. The experimental results show that compared with the traditional method, the proposed intelligent detection method of defect data detection success rate increased by 11.93%. Visible X-ray digital imaging is more suitable for intelligent defect detection.

As one of the basic devices of spintronics, spin valve contains abundant physical effects in addition to its high magnetoresistance ratio (MR) value. Owing to the spin filter effect in two dimensional (2D) materials especially transition metal dichalcogenides (TMDs), the spin polarized current from ferromagnetic electrodes (FEs) passing through the 2D materials makes high- and low-resistance states in FE/2D/FE vertical junctions according to magnetization alignment of FEs. In this work, we fabricate vertical spin valve junctions utilizing exfoliated thin layer of molybdenum diselenide (MoSe₂) with the help of ultra-clean transfer technique. The current–voltage (I–V) performances exhibit an ohmic contact between the MoSe₂ and FEs. The MoSe₂ which act as the interlayer shows metallic behavior. We found a magnetoresistance ratio varies from 1.1% at 4K to 0.3% at 300K and independent of bias current. Combined with the reported resistive-switching (RS) performance of similar structure in the MoSe₂ based memory device, our result is prospective to be conducive for future spintronic applications.

An optical filter is proposed and demonstrated based on a micro-ring resonator (MRR) embedded in a Fabry-Perot (FP) cavity. By exploiting coherent interference within the FP cavity to reconstruct the transmission spectrum of the MRR, high extinction ratio (ER) and narrow bandwidth for periodic notch filtering is obtained. The FP cavity is composed by two circular Bragg grating (CBG) mirrors, and the two mirrors are well placed so that the light wave can be constantly reflected between the two mirrors to generate resonance. The device is simulated theoretically and fabricated on a silicon-on-insulator (SOI) platform. The proposed optical filter has an ER up to 31dB and a minimum 3dB bandwidth of 10pm according to the simulation result.

Seawater salinity is one of the basic elements of marine hydrological observation, and seawater conductivity measurement is an important means of salinity measurement. In order to improve the measurement accuracy of seawater conductivity sensor, a seven-electrode conductivity sensor is developed by using lock-in amplifier technology, which can measure the seawater conductivity by detecting the voltage and current signals in the strong noise environment. The comparison experiment was carried out by using seven-electrode conductivity sensor and seabird CTD sensor SBE 37-SI, the indication error of conductivity measurement is within ±0.0003s/m, which can meet the needs of high-precision measurement of seawater conductivity.

Due to its unique advantages of low loss, pretty anti-interference performance and good heat dissipation, traditional metal waveguide devices were widely used in communication and radar fields. What’s more, millimeter T-shape waveguide power divider is widely used in the millimeter system because of its more simple structure, but the common sub-four waveguide divider is difficult parts for their complex shape and higher machining requirements. We design a kind of sub-four waveguide divider which combines waveguide slot bridge and ridge waveguide.

In this paper, the effects of multi-radiators on the electromagnetic scattering characteristics of coated flat plate in half space are investigated. The electromagnetic scattering characterization of coated flat plate are represented by active radar cross section (ARCS) under multi-radiators. Simulations were conducted to research the effect of radar absorbing materials (RAM) and multi-radiators on the electromagnetic scattering characteristics of flat plate in half space. Through the resultants, it can be concluded that the electromagnetic scattering characteristics are significantly influenced by RAM and multi-radiators.

In order to promote the work of prevention and management of coal mine water disaster in China, it took Panlong coal mine, Xiayukou coal mine and Xiangshan coal mine in Hancheng mining area as object of study, which were compared from 7 classification factors of hydrogeological type, time and scale of water inrush. Ordovician limestone water inrush and water inrush from old and empty areas were then thought out to be the major types of water disaster in Hancheng mining area.

We propose a six-layer waveguide structure embedded in a single layer grating with a microcavity based on the guide mode resonance (GMR) effect, and realized a tunable notch filter in near infrared wavelength. The structure shows a very narrow filtering bandwidth and high tunable resonance absorption. The propagation characteristics are analyzed and calculated by using the finite-element method, and the reflection spectrum shows different properties under different structure parameters. The result of FWHM (full width at half maximum) is less than 0.001nm with a filtering resonance wavelength of 1550nm under a TM polarized incidence. The resonance wavelength is mainly controlled by the period of the grating layer; it shows a red shift from 1536.17nm to 1563.73nm under changing the period from 790nm to 810nm with 5nm interval. The filtering structure presents potential applications in optical communication, noise suppression and optical sensing.

Intelligent robots have the advantages of high working efficiency, fast service and access to dangerous environment. With the rapid development of intelligent robot technology, in order to solve practical problems such as garbage classification, storage management and material transfer, intelligent classification robot "Xiaobi" is designed. " Xiaobi" mainly contains RENESAS main control board, speech recognition module, image recognition module and mechanical arm module; uses speech recognition, color recognition, contour extraction, inverse kinematics analysis and other technologies. Compared with the existing classification robots, in addition to grasping and classification, it can achieve speech interaction, target recognition, QR code recognition and other functions. It has characteristic advantages such as multiple modes of operation, friendly interface and strong expansibility. It has great potential in practical application.

Today titanium alloy is widely used in aviation, aerospace, deep sea and other high-tech manufacturing industries, as an important structural metal. Aviation industry enterprises have been using titanium alloy, and the need for high-quality titanium keeps increasing, following the increase of aircraft production rate at home and abroad. Therefore, the use of residual titanium recovery and secondary use appears to be particularly important. This article introduces the current status of titanium alloy processing, reviews the current situation of titanium alloy recycling at home and abroad, analyzes the problems faced by the current development, as well as suggestions on the future development of titanium alloy recycling.

A method for analyzing the surface characteristics of electrical contact of aeronautical electrical lines based on infrared thermography was proposed. Through the analysis of electric contact reliability model, it is considered that contact material, contact form and surface condition are the main factors affecting contact resistance. In the actual working environment, oxidation and oil pollution can increase the resistance of the electrical contact film, resulting in the "deterioration" of the surface condition. Taking the universal electric connection components as the electric contact carrier, the electrification experiment is conducted according to the different development degrees of oil pollution under the action of rated working current. Based on the surface temperature spectrum analysis, it is concluded that after a certain time of heat accumulation, the distribution characteristics of temperature contraction lines on the electrical contact surface can reflect the development degree and difference of surface deterioration to a certain extent. It has certain technical traction and reference value for the evaluation of electrical contact reliability.

Excessive axial force is an important problem affecting product quality in Shaogang 3450mm plate rolling mill. In order to solve this problem, In order to solve this problem, this paper analyzes the impact of bearing seat clearance on the axial force. Based on the actual measurement of the unit bearing seat clearance, the unit system dynamics model was established, and on this basis, the reaction force response was calculated and analyzed, and the influence of the clearance on the axial force was theoretically verified. At the same time, the clearance contact model between the bearing seat and the archway was established by ADAMS, and the relationship between the bearing seat clearance and the axial force of the unit was simulated and analyzed. On the basis of theoretical research, process improvement measures were proposed, which effectively reduced the axial force from about 5% of the rolling force to about 1.4%, and greatly reduced the thickness deviation of the rolled plate.

This article introduces several typical integrated air data systems. By introducing air inertial navigation systems, multifunction sensors, and air data systems based on big data, these systems are compared in terms of software and hardware, daily maintenances, data characteristics and so on. Then it puts forward advantages and disadvantages of different air data systems. Finally the article proposes new prospects for the development of the systems.

According to the requirement of online monitoring of fouling and slagging in waste heat boiler of coal gasifier, a method based on coplanar capacitance principle for measuring the pollution thickness is proposed. A capacitance sensor constituting with a circular positive electrode and an annular negative electrode is designed in current study. The sucrose is selected as the deposition medium to substitute the gasification slag. The capacitance and space electric field of sensor are simulated by employing the ANSYS Maxwell. The effects of structural parameters and shielding layers on the capacitance and measurement sensitivity of sensor are analyzed. The results show that with the medium thickness increasing, the capacitance firstly increases then stabilizes and the sensitivity sharply decreases. The sensor with the larger positive radius or the smaller negative radius behaves better sensor performance. The inter electrode and edge shielding has little effect on the capacitance, however, the bottom shielding may improve clearly the capacitance signal strength.

As the center of the society of knowledge and economy, high schools are the important base to accept and transfer advanced culture as well as the crucial place to change knowledge into economic power. Based on careful research, the thesis standing on the perspective of intellectual property rights education for vocational students, aiming at existing problems of intellectual property awareness education in vocational college. Development of intellectual property to today’s college student awareness of the reality of the level of awareness based on how higher education in line with China and the world needs of economic development of the double standards, raising today's vocational students awareness of intellectual property.

Due to the influence of elevator pit environment, polyurethane buffer for elevator is prone to aging, resulting in its buffer performance failure. In this paper, the accelerated aging test of polyurethane buffer for elevator was carried out at different time. The mechanical properties and mass changes of the samples after different aging time were analyzed. The results show that the aging time has an obvious effect on the properties of polyurethane materials.

The failure causes of a burst convection tube used in heat recovery steam generator were analyzed by the chemical composition, optical microscope and scanning electron microscope analysis. The results show that the metallographic microstructure of the burst convection tube is ferrite and pearlite. Based on the scanning electron microscopy analysis, the thinning of the burst convection tube wall is caused by erosion. Ultimately, the convection tube bursts due to insufficient strength.

The high temperature creep rupture behavior of SA387Gr91 martensitic heat-resistant steel welded joint was studied in this paper. Accelerated creep tests were carried out at 545°C and 565°C and stresses ranging from 175 to 225Mpa. The creep test curves of SA387Gr91 martensitic heat-resistant steel welded joint were obtained. Microstructures of SA387Gr91 martensitic heat-resistant steel welded joint after creep and fractographs were analyzed by scanning electron microscope and optical microscope. From the macroscopic fracture morphology of the specimen after creep test, it can be seen that the fracture position is in the heat affected zone. The values of reduction in area range from 82.12% to 87.57%.

With the change of energy consumption structure, cryogenic liquids are increasingly widely used, such as liquefied natural gas (LNG), liquid hydrogen, liquid nitrogen, etc. Austenitic stainless steel is widely used in construction of cryogenic temperature pressure vessels as a kind of material with good cryogenic temperature resistance. It is difficult to give full play to the high tensile strength and high plasticity reserve of austenitic stainless steel by using conventional design methods, which results in material waste and cost increase. The strain strengthening technology of austenitic stainless steel is the more effective method to realize the lightweight design and manufacture of cryogenic pressure vessel and reduce the cost. In this paper, experimental study on mechanical properties of S30408 with strain-strengthening were carried out.