Materials assembly and integration at multiple length scales are critical to the functioning of new generation solar energy devices, and call for basic science informed design and elaboration. The key is to understand and leverage the intrinsic properties of the tailored materials as well as the interplay between the material components so as to realize the desired functions.This contribution will present some of recent results in interfacing and assembling various nanostructures by solution processes. The novel materials have been explored as efficient light absorbers, carrier transporters, interlayers and surface reaction promotes for high-performance solar energy conversion device, particularly perovskites solar cells and photoelectrochemical cells. Implications of these results on the future development of new solar energy devices will be discussed.

Aiming at the calculation problem of vehicle exhaust emission in the pollution gas monitoring system, a gas emission calculation model based on the optical flow method is proposed in this paper. The two infrared cameras are applied to capture the multi-frame gas image sequences. Optical flow method then is used to obtain the optical flow velocity field matrix of the gas plume. Finally, we obtains the instantaneous gas displacement by combining the optical flow velocity field matrix with a two-dimensional gas concentration map. By using different optical flow methods for experimental comparison, Farneback optical flow method has better adaptability in the model and can achieve a higher processing effect. The maximum fitting degree of gas displacement calculated by the optical flow method reaches 93%. The operation speed is also better than Lucas-Kanade optical flow method and Horn-Schunck optical flow method, while the accuracy is maintained. In calculating low emission speed and high emission speed gas, Farneback optical flow method achieves more reliable stability. A new idea for non-contact gas monitoring is provided.

To address the image distortion caused by the large-field camera in the panoramic system and the undulation and shaking of the stitched image of the target caused by the motion or sway of the mounting base, based on the distortion principle and the dynamic stabilization mathematical model for panoramic images, the distortion correction is performed for origin images captured by the camera.Then, in order to obtain a panoramic image, rotation transformation, spatial projection, and smoothing of each pixel of the original image are obtained according to the posture data of the installation base. Finally, algorithms based on deep learning are used for target detection and recognition. The results of training and testing on the established data set show that the algorithm designed in this paper can better correct the panoramic image, and the real-time detection speed of ship target is up to 25 fps, and the accuracy rate is up to 80%, which shows that the algorithm can meet the requirements of image stability and real-time detection of ship target under dynamic conditions.

For objects with smooth surfaces, traditional reconstruction algorithms cannot accurately restore their shape characteristics, and the use of polarization information to reconstruct the target object will solve the above situation well. Due to the ambiguity of the azimuth angle of the incident surface, binocular estimation is proposed. Parameter removal of ambiguity angle, the Stokes parameter is used to represent the polarization state information under two viewing angles. The relative pose is estimated from two images with polarization information. The relative rotation and translation are indispensable, then the problem can be converted. For the least squares optimization problem, the azimuth angle ambiguity problem is eliminated by obtaining the optimal solution. The experimental results show that the image resolution of the depth map is higher after the ambiguity is eliminated by the algorithm, the shape information after reconstruction is accurate, and the target object texture. It is highly reducible and easy to realize in engineering.

The angle measurement error detection of photoelectric encoder is an essential work in the development and production process of encoder. At present, the detection process of manual detection device is complex, inefficient and time-consuming, so it is difficult to be used for mass production product detection. In order to make up for the shortcomings of the existing manual detection device, this paper takes the autocollimator polyhedral prism combination as the measurement reference, uses the stepper motor and STM32 to realize automation, and designs an automatic detection system for angle measurement error of absolute photoelectric encoder. The detection principle, software and hardware design of the system are described. The accuracy of the system is analyzed and calculated. The expanded uncertainty is 1.6″. After manual and automatic detection of the same encoder, the results are 6.3″ and 7.3″, respectively. The experimental results show that the automatic detection result of the detection system is accurate. Through this system, the detection process does not need manual operation, and the efficiency is high. In the batch detection of photoelectric encoder, the advantages of this system can be reflected; In addition, compared with the traditional manual detection, this system can reflect the real working process of the encoder when it rotates at low speed.

The optical window is easy to breed aquatic organisms in the underwater enviroment for a long time. Attached aquatic organisms affect the observation and use of optical windows. In order to restrain or remove the attached aquatic organisms, the method of underwater high speed jet is used. Underwater jet is different from air jet in that it consumes a lot of energy due to the action of environmental water. Because the flow field of the jet in front of the target has a very important influence on the cleaning effect, the underwater jet flow field analysis and experimental study are carried out. In this paper, the flow field parameters before the target are obtained through the analysis of the underwater jet flow field. According to the results of flow field analysis, an underwater jet device is designed. Underwater jet device is composed of submersible motor, pump, nozzle and control box. The test device is used to carry out the underwater jet test, and the flow velocity of 2.2 meters per second at 300 mm before the nozzle is obtained. Using the underwater jet device to regularly carry out the underwater jet to the optical window in the underwater environment can remove the aquatic organisms and dirt attached at the initial stage, and can also inhibit the growth of aquatic organisms, so as to keep the underwater optical window clean.

In order to further strengthen the protection measures for the operation of the optical cable, a dual-index scheme based on the distributed optical fiber vibration system for the equipment identification and vertical distance judgment of the optical cable external damage event is proposed. The fiber vibration signals in real time are acquired. The multiple features of time-frequency domain signals are analyzed. The key features such as the affected fiber section, frequency energy ratio, frequency peak value and distribution are extracted. The type of equipment and vertical distance of the incident of external optical cable breakage, the grading early warning of the vertical distance, and the effective activation of corresponding timely response are measured. The case shows that this scheme not only meets the recognition accuracy rate, but also ensures the recognition efficiency of the system, which has high practical application value.

Voltage and reactive power compensation are the key to the stable and efficient operation of power system. In order to ensure the long-term stable operation of temporary power supply system, a multi-mode power supply method considering voltage stability and reactive power compensation is proposed. According to the transmission characteristics of stable voltage drive circuit, the compensation controller and reactive power compensation battery are connected to complete the construction of multi-mode power supply environment. The static reactive power compensation generator is designed to compensate the reactive power compensation effect of temporary power supply system and realize dynamic reactive power compensation. The experimental results show that, compared with Ieee-118 transmission control method, the stability of the whole voltage system is obviously improved after the application of multi-mode power supply method, the PID reactive power compensation coefficient is also increasing, and the stable transmission problem of temporary power supply system is effectively solved.

Calibration is one of the core processes in intersection survey. In classic calibration, the calculations of intrinsic and exterior parameters are separately and require amount of stable and static control points. However, in large FOV and sky-background survey camera calibration, above mentioned conditions cannot be satisfied. In this paper, a denseness star-arc calibration is proposed. To achieve better results, the WTLS is used to eliminate the influence of error from RTK and UAV identification. To test the performance of the proposed method, cameras with the FOV of 77°×66° are used. And the cameras are set with different pitches and azimuths. Experimental results show that the proposed method is able to gain accurate result. Calibration error is less than 0.3°.

By using Zernike polynomials to describe the wavefrontdistortion of beams, the focusing performance of super Gaussian beams in far field are studied based on the generalized Huygens-Fresnel diffraction integral. The influence of astigmatism and coma on the intensity distribution at focusing position and the power in the bucket(PIB)are analyzed when the aberration of Ca system decreased to λ/13. The results show that the aberration will lead to the beam broadening at the focusing position, and the PIB in 80% decreases obviously, but the spot diameter in 95% of the energy range is still within the design value range, which meets the overall design requirement.

Graphene-silicon nitride optoelectronic devices have good performance in optoelectronic integration, but the visibility of transferred graphene on silicon nitride is usually not good, which makes it difficult to judge the quality of transferred graphene. Therefore, it is of great significance to study the visibility of graphene on silicon nitride. This paper first derives the theoretical calculation formulas for the optical reflectance and the optical contrast of graphene on the multilayer structure based on the Fresnel formula, and then uses MATLAB to simulate and analyze the influence of silicon oxide thickness on the optical contrast of graphene on the silicon nitride/silicon dioxide/silicon multilayer structure. The simulation results show that the optical contrast of graphene can increase significantly under the specific thickness of silica layer, which makes graphene clearly visible under microscope and can better judge the transfer effect of graphene. When the silica thickness is 2 547 nm, the contrast between graphene and surrounding medium can exceed 0.3. Lastly, two samples with SiO2 thickness of 2 330 nm and 2 690 nm were fabricated and tested. The analysis reveals that the main reason is the deviation of material deposition thickness and light source wavelength, which provides guidelines and indications for the further improvement of device fabrication and test methods.

The reaction mechanism of electroless nickel plating is analyzed emphatically. The reaction step of reduction between activating and electroless plating is added in this article. The process for electrodes nickel plating on diamond powder is optimized by orthogonal experiment. The most optimal parameters are nickel sodium 26 g/L, sodium hypophosphite 22 g/L, sodium citrate 8 g/L, sodium formate 8 g/L and pH 9~10. The morphology, composition and phase structure of the Ni-P coating are analyzed by the SEM, EDX and XPS techniques. The results show that the phosphorus mass fraction of the compact-structure Ni-P coating obtained under the optimal conditions on diamond powder is 7.78%, and belonging to a middle-phosphorous coating. The hardness, wear resistance and corrosion resistance of middle phosphorous coating are moderate and the magnetic of middle phosphorous coating is small, which is conductive to sebsequent electroplating.

Aiming at the problem that the performance of high precision fiber optic gyroscope with long coil degradation under vibration condition, the error mechanism of fiber optic gyroscope caused by mechanical environment is analyzed from the angles of optical path, structure and closed-loop control, and the system model of digital closed-loop control is established. According to the analysis and modeling results, a method to improve the vibration resistance of fiber optic gyroscope from the aspects of optical design, optical assembly technique, structure design and optimization of closed-loop control is proposed, and the gain parameters of optimized closed-loop control are designed to improve the response of the vibration environment. After optimized parameters, the anti-vibration performance of the fiber optic gyroscope has been greatly improved. The results also prove the correctness and effectiveness of the improved scheme, and achieve a breakthrough in the application of high precision fiber optic gyroscope in dynamic environment.

In order to obtain higher output power, the design and research of four-channel high-power microwave combiner with the method of polarization orthogonal mode coupling is proposed in this paper. The TE11-mode has vertical and horizontal polarizations with very different coupling coefficients. The electromagnetic wave coupling and energy transmission are designed and verified with same polarization direction in the two-way three channel coupler. Finally, a feasible four-way high-power microwave combiner is designed to make four-way microwave combined and output based on their theory and simulation. The combiner is mainly composed of input section, coupling section and output section. The four input ports are connected to four input section. The output section is connected to output port. The four microwaves use the long and narrow coupling slots coupled to the main-channel, and output through the common port. By electromagnetic simulation software, the energy coupling efficiency of the sub-channel to main-channel can reach more than 95%, which can efficiently realize the high-power efficiency combination of four-way microwave, and provide an application path for power combiner. Directional couplers are widely used in many fields which are related to microwave. The development of technology is putting higher requirements for directional couplers with broadband and higher power capacity. Waveguide structure, with its large power and simple processing process has become the basis structure of high power directional couplers. An synthesis method for X band power based on circular waveguide. In this paper, a four-road synthesis of circular waveguide coupler is proposed, the cylindrical waveguide which is joined with the output port is named main channel, and the other cylindrical waveguides are called associate channel, the four associate channel are respectively back to back with the main channel. The energy of associate channel which uses long slits is coupled to the output port of main channel, and the coupling energy efficiency of the associate channel is above 95%.

With the increasing demand for high-precision TFT-LCD products, especially when the large-scale production line of 8.5 generation and above produces small-scale products such as mobile phones, it is difficult to guarantee the exposure uniformity and overlay accuracy of color film exposure machine, which affects the development and production of high-precision TFT products. Through the research on the automatic compensation function of color film exposure machine, it is found that using the gap automatic compensation of the exposure machine, the difference value is automatically corrected to each shot, so that each shot exposure gap is closer to the actual gap, and the gap difference between shots is smaller, which can ensure the exposure uniformity. The actual shape of OT deformation can be more effectively compensated to get a shot shape more matching BM, which can improve the overlay accuracy. The color film exposure machine can ensure the exposure uniformity and overlay accuracy.

At present, China has a number of strong optical technology teams, including basic theories and applications, but there is no optical design CAD software can meet the lens design application in the market. After nearly 10 years of preparation and two years of concentrated project development, the project team has completed a highly integrated optical design software and named it CAXCAD. The software currently realizes the high-efficiency basic framework and the integration of multiple modules, in core ray tracing, geometric analysis and evaluation, FFT PSF MTF diffraction calculation, DLS optimization, merit function operands, multiple configuration, coordinate break off-axis simulation, etc.