The progress of humankind has been marked by five main waves of innovation. Each wave has transformed our industries and societies， yet is also coupled with the consumption of resources， pollution， and energy/water shortage. In contrast， honed by billion years’ evolution， nature has developed extraordinary principles which are characterized with green energy and resilience. This paper focuses on how nature-inspired innovation will address the grand challenges facing us such as water， energy and health engineering.

Wave-absorbing composite materials are fabricated with four-needle zinc oxide and carbon black as the absorbent， and silicone resin as the binder. The influence of the content of the absorbent and the thickness of the composite material on the absorbing performance is studied.At the same time， scanning electron microscope， vector network analyzer and other instruments are used to characterize the microscopic morphology and electromagnetic properties of composite absorbing material samples with different mass fractions. The results show that within a certain range， the thickness of the sample， the content of carbon black and the content of tetrapod zinc oxide increase， which will improve the absorbing performance of the sample.When the thickness of the sample is 2 mm and the mass fractions of carbon powder and tetrapod zinc oxide are 8% and 10%， respectively， the minimum reflection loss value of the composite absorbing material can reach-14.68 dB， which is in line with the current light and thin broadband absorbing material development trend. Therefore， the composite material has the advantages of low absorbent content， lightness and thinness， and high elasticity， and has potential application prospects in the field of electromagnetic shielding.

Based on the sensor response and the electronic diffusion principle， several main factors that should affect the crosstalk characteristics of CMOS array are analyzed. Several common optoelectronic materials， such as germanium， silicon， and gallium arsenide， are selected to analyze the influence of material properties on the crosstalk characteristics of CMOS arrays. The crosstalk voltages of the devices with different material are calculated under different incident conditions. The results show that under the same conditions， the CMOS array made of germanium material has the largest electrical crosstalk output. When the structural conditions are consistent and the power of the incident light is 200 μW， the crosstalk of germanium material CMOS array is 58.97 mV and 115.81 mV higher than which made of silicon and gallium arsenide materials， respectively. Structural parameters have the same influence rules on CMOS arrays of different materials， but the crosstalk changes of germanium material CMOS are the most significant. While other parameters remain unchanged， when the depletion layer width is 1 μm， the crosstalk output of germanium material CMOS is 56.67 mV and 121.84 mV higher than which made of silicon and gallium arsenide materials， respectively. The analysis results provide theoretical reference data for optimization and crosstalk processing of CMOS array in practice.

The steep drop in efficiency seriously affects the output performance of AlGaN-based deep ultraviolet light-emitting diodes (DUV LEDs)， and is also a bottleneck problem for DUV LEDs in recent years. DUV LEDs with conventional electron blocking layer (P-EBL) and Al composition triangular graded P-EBL are investigated numerically in this paper. The distribution characteristics of energy band， electron current， hole concentration， electric field， internal quantum efficiency， output power and spontaneous emission spectrum are investigated.The simulation results show that when 260 mA current is injected， compared with the conventional P-EBL structure， the efficiency drop of the Al composition triangular graded P-EBL structure DUV LED is reduced by 5.85%， which improves the output performance of the DUV LED. Based on the numerical simulation and analysis， these improvements on the device characteristics are attributed to the remarkable improvement of the electron leakage and hole injection efficiency， which results from the higher effective conduction band barrier height for limitting electrons， and the higher kinetic energy for hole transportation in the P-side.

In this paper， a reverse tracing model is stablished according to the viewpoint of reverse Hartmann test to analyze transmission phase measuring deflectometry (TPMD)， and an algorithm which can be used to measure wavefront aberration of single lens or complete lens is proposed. Based on the concept of wavefront aberration， the feasibility of this method is theoretically verified by comparing the optical path difference between the forward and reverse models， and the effectiveness of this method is verified by simulation. The wavefront aberration of the tested element is obtained by the actual ray calibration， system model ray tracing and N-step phase shifting algorithm. In the experiment， the wavefront aberration of a biconvex lens is measured to verify that this method can accurately measure the wavefront aberration. By comparing with the interferometer result， the RMS difference of them is only 0.03 μm. The result shows that this method has the advantages of simple device， low cost and fast measurement， and provides a new off-line or on-line/on-situ testing method for measuring the wavefront aberration of lens without interferometer.

A new real-time three-dimensional(3D) shape measurement based on single-shot color composite grating projection is proposed. In the methods， the three frames of phase-shifting sinusoidal gratings with a shifted phase of π2 are respectively coded into the red (R)， green (G) and blue (B) channels to form a single-shot color composite grating. When this color composite grating is projected to the object， only a single frame of color deformed pattern is needed to capture. By color separating method， the corresponding three-frames of monochrome phase-shifting deformed patterns with a shifted phase of π2 can be demodulated. Due to the color crosstalk and chromaticity imbalance among the three color channels， the least square method for DC component of the three frames of monochrome phase-shifting deformed patterns is used to correct the background consistency， so as to obtain the three-frame corrected monochrome phase-shifting deformed patterns. Using the established 3D reconstruction physical model， the 3D shape of the object can be restored. The experimental results verify the feasibility and practicability of the proposed method. Further experimental results show that the measurement accuracy of the proposed method is better than that of the traditional single-frame color PMP. Because the proposed method only needs one frame of color composite grating to reconstruct the 3D shape of the measured object， it has a good application prospect in real-time 3D measurement.

Sulfur hexafluoride (SF6) decomposition characteristic component detection is one of the most effective methods to judge the early latent fault of gas insulated equipment. The operation status of electrical equipment can be effectively evaluated by monitoring the type and concentration of decomposition characteristic components， so as to avoid insulation accidents. Raman spectrum analysis technology can realize the non-destructive detection of gas samples with single wavelength laser， and has excellent applicability and efficiency for the detection of SF6 decomposition characteristic components. In this paper， a gas molecular model is established based on the B3LYP method of density functional theory (DFT). The molecular model is optimized by 6-311G (2df， p) basis set， and the Raman frequency shift characteristics are simulated. At the same time， four kinds of experimental platform of Raman spectrum detection are built based on Raman spectrum characteristics. The results show that there is a good correlation between the calculated and measured values of DFT and NIST standard values. The characteristic peaks of CF4， CO， H2S and SO2 in the calculated values are 908.97， 2 221.11， 2 688.82， 1 175.24 cm-1 respectively， which lays a foundation for the qualitative and quantitative analysis of SF6 decomposition characteristic components by Raman spectroscopy.

Aiming at the effect of image noise in the real-time detection system for out-of-limits of rail vehicles on the reliability， accuracy and detection speed of over-limit real-time detection， the on-site image noise is analyzed. The system hardware facilities and software framework are optimized. The image noise is processed， and the software algorithm is improved and optimized. It is shown， by the field test results， that the stability， reliability， accuracy and speed of the system detection have been greatly improved， which meets the needs of real-time detection on the production site.

Ship deformation is one of the physical phenomena that restrict the mission effectiveness of ship weapon systems. Aimed at how to measure the deformation of ship accurately， a method based on joint matching of angular increment and attitude matrix for measuring ship deformation is proposed. This method only relies on gyroscopes which can provide angular motion information of carrier， trough reliable strategy to estimation ship deformation， under the condition that initial alignment and the velocity-position update for inertial navigation are not required， high precision measurement for ship deformation can be achieved. Simulation experiments show that estimation accuracy of the proposed method has is better than 35″(Root mean square)， which can provide support for scenes that requires ship deformation information such as alignment， artillery launch.， etc.

In this paper， based on the blackbody radiation theory and the test principle of the minimum resolvable temperature difference (MRTD)， the imaging quality evaluation parameter for infrared thermal imager， the quantitative relationship between infrared radiation difference and temperature difference of the target and background at different ambient temperatures is established. And then the ambient temperature influencing factor for infrared thermal imager is proposed. The results show that the MRTD of IR thermal imager with good non-thermal design and the ambient temperature influencing factor has the same trend with the change of ambient temperature， and the ratio of the two tends to be the same at different temperatures. This conclusion can be used to evaluate the imaging quality of infrared thermal imager under temperature stress.

The working principles of traditional inertial/celestial integrated navigation are generally divided into two types. The ψ angle output from astrometry analyzes and corrects the velocity and position of inertial navigation directly. Or the ψ angle is used to measure and estimate the velocity and position of inertial navigation indirectly. Aiming at the problem of unsatisfactory integrated navigation effect due to insufficient use of the gyro constant zero bias estimation information with large observability in the two principles， an all-solid-state strapdown inertial/celestial integrated navigation technology is proposed in the paper. The technology fixes the strapdown inertial navigation system with the large field of view star sensor， and uses the Euler error angle as the measurement information of the Kalman filter to estimate and feed back the gyro constant zero offset in real time to correct the strapdown inertial navigation system. It can quickly and effectively suppress various errors caused by gyro drift. The simulation results of measured data show that it can make longitude error， latitude error， heading error and gyro constant bias error stable and convergent quickly using Euler error angle as the measurement information of Kalman filter. In the long endurance test， the longitude error can be no more than 0.5 nautical miles， latitude error can be no more than 0.2 nautical miles， heading angle error can be no more than 30 arcsec. And in the short endurance test， the longitude error can be no more than 0.5 nautical miles 25 nautical miles， latitude error not more than 0.15 nautical miles， heading angle error not more than 20 arcsec. Therefore， the technology has good adaptability for both long-term navigation and short-term navigation， and has practical value and research significance.

Chaotic encryption is widely used in the field of image encryption due to its initial value sensitivity， pseudo-randomness， and unpredictability of motion trajectories. Deep learning (DL) as a method of machine learning was proposed for decades. With the development of computer’s performance， the practicality of deep learning has been proved more and more. It has achieved good resultsin many fields. In this paper， we propose to attack Lorenz chaotic encrypted system of grayscale images by the deep learning method via Residual Networks. After the training process to a series of input and output plaintext-ciphertext pairs， ResNet can fit the process from ciphertext to plaintext. We can finally recover the image approximate to the plaintext image accordingto the ciphertext which is independent to the original plaintext-ciphertext pairs set. Numerical simulation has verified that the result recovering from the chaotic encrypted system is very good.

The living environment is getting worse， the threat target tends to be hidden and the mission is complex and arduous in modern battlefield. In order to save the lives of soldiers and improve the operational efficiency， the ground reconnaissance robots have become the necessary equipment for the army to turn to non-contact， asymmetric and zero-casualty mode. Starting from the actual engineering application scenarios， a mobile chassis of backpack reconnaissance robot is developed based on four-driven track mechanism. The motion model is established and the feedback control law of mobile chassis system is designed. Finally the test of obstacle-climbing stability and trajectory tracking is carried out. The experimental results indicate that the mobile chassis could have strong obstacle climbing performance and accurate trajectory tracking ability which would meet the requirements of backpack-reconnaissance robot. The paper provides engineering design experience for later robot integration development.

A known plaintext attack (KPA) algorithm based on ResNet is proposed for encryption system based on double random phase amplitude encoding (DRPAE). Our attack mainly uses a series of plaintext-ciphertext amplitude image pairs to make training set in residual network. Inputting plaintext ciphertext into neural network for training can make neural network fit the encryption process from ciphertext to plaintext. Independent of the ciphertext outside the training set， the trained network can effectively recover the original image， so as to attack the encryption system and decrypt the image. In this paper， the validity and feasibility of the attack method are analyzed theoretically and verified by computer simulation.

The reliability of power communication network plays an important role in the safe operation of smart grid. The reliability model of the typical electric power communication system is established by using the hierarchical modeling. First， the power communication system is decomposed into terminal layer， access layer， sub-station communication layer and master station control layer subsystem by means of top-down decomposition method. Then， the reliability of basic products is evaluated by using parameters such as mean time between failures， mean time without failures and mean time to repair， and the reliability of each subsystem is evaluated by using non-redundant system， fully redundant system， partially redundant system and collateral system. Finally， the bottom-up synthesis method is used to evaluate the reliability of the whole network according to the topology of the system. The reliability analysis method proposed provides a theoretical method for the reliability evaluation in power communication network.

In order to improve the accuracy， a new method is proposed to obtain the corneal topography based on phase measurement deflectometry and the traditional placido disk system. The proposed method utilizes a geometry configuration where the normal at the apex of the human eye is collinear with the optical axis of the camera and parallel with the normal of the screen.Two-dimensional orthogonal fringe pattern displayed on the screen is reflected off the human eye， and the deformed fringe image is recorded by camera. Then the coordinates of the screen and human cornea are calculated by phase extraction algorithm and iterative algorithm， respectively. According to the geometric relationship between them， the corneal topography can be obtained. The numerical simulation demonstrates that the measurement accuracy of the radius of curvature and diopter of the model eye can theoretically reach ±14.7 μm and ±0.07D， respectively. Finally， experiments are conducted to measure a spherical element with a radius of curvature close to that of the human eye. The results show that this method has the advantages of highaccuracy， simple deviceand low cost.

In the assembly process of printed circuit board components， some problems (misalignment of solder paste， little tin and cracking) caused product quality degradation. It is of great significance to improve the yield rate through high-precision solder paste inspection， and this method has attracted widespread attention in the industry. The phase profile measurement method needs to project the grating fringes on the PCBA， and detect the defects of the circuit board by detecting the deformation of the fringes. The accuracy of the fringe projection determines the detection accuracy of the system. Therefore， a high-quality projection objective is necessary to complete this type of inspection. A laser diode as the illumination source is used. The lens structure adopts the classic double Gaussian form and is optimized by Zemax software. The design results show that the performance of the objective lens is close to the diffraction limit. The modulation transfer function is above 0.4 at 30lp/mm， and the maximum distortion is less than 0.3%. The objective lens realizes high-precision projection of grating fringes， and the design results and methods can provide references for the design of optical instruments in the electronic equipment manufacturing industry.