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The design and simulation methods of composite components are vital to the performance and application research of composite materials. Research pertaining to composite component design and simulation systems begins late in China and confronts many risks，including inadequate theoretical levels，lack of independent standards，weak foundation of simulation software，and segregation between design and manufacture. Therefore，the large-scale application of composite components in major equipment can hardly be realized. Considering the problems and challenges，this study analyzes the macro demand for composite component design theory and simulation technique，summarizes the development status and main trends in China and abroad，and proposes the key directions in China：design theory of composite components under extreme and multi-field environment，dynamic analysis and design theory of composite components，data-driven simulation method of composite components，and simulation evaluation method of strength and life of composite components. We suggest that research should be conducted on multi-field and multi-scale design technology of composite components for equipment engineering applications，performance design technology of composite components under dynamic load，data-driven design and simulation technology of composite components，and strength and lifespan simulation software platform of composite components，thereby comprehensively improving the design and engineering application level of composite components in China.

Food-medicines are a significant component for traditional Chinese medicine, Chinese cuisine culture, and the Healthy China initiative. Herein, we summarized the opportunities, development status, problems, and countermeasures for the food-medicine industry in China by using literature analysis, data mining, and expert consultation. Our research indicates that food-medicines have potential values in preventing and treating chronic diseases as well as delaying aging, and they are expected to become a daily material basis for disease prevention. Moreover, food-medicines are crucial for promoting the domestic and international economic cycles and supporting rural revitalization. Furthermore, we suggest that China should (1) increase its investment in research on foodmedicines to protect people’s health; (2) improve the regulation system to strengthen supervision and establish regulation and quality standards systems that accord with Chinese conditions; and (3) enhance international communication and trade to facilitate the implementation of the Belt and Road Initiative and the establishment of a global community of health for all.

The fluidity of a cement mortar is a key factor for 3-D printing technology and cement-based materials. This paper introduces the measurement of the fluidity according China’s national standard, and a mathematical model is established to reveal main factors affecting the measure accuracy. The result shows the fluidity reveals mainly the rheological property of the mortar, but it is also affected by other measuring conditions, e.g., the vibration properties of the measuring table.

Twin rectangular-shaped tunnels were constructed vertically beneath the adjacent pipelines in water-rich gravel ground. An analysis was carried out using measured datum to reveal the response of the overlying pipelines to the construction of shallow tunnels. The method of superposition was applied for describing the displacement profile of the overlying pipelines. The transverse profile shapes for the pipelines remain different. The profile of the gas pipeline and box culvert firstly displays a single-trough “n” shape and “U” shape, respectively, whereas the final profile of the pipelines displays an unsymmetrical double-trough “W” shape. It is also found that the safety of the existing pipelines was generally ensured, except for one monitoring point of the box culvert on the right side of the shallow tunnel. It implies that the larger grouting thickness beyond the excavated outline of the shallow tunnel should be conducted in similar cases.

A series of local prototype tests are conducted on the Sutong GIL (Gas-Insulated Line) and Shiziyang Tunnel. These tests investigate the redistribution law of segment deformation and the bending moment during construction. The results reveal that the transfer ability of deformation and the bending moment improve with an increase in the longitudinal force. Stage characteristics are observed for the effect of the longitudinal force on the opening of the circumferential joints. Segments are fully contacted for the circumferential joints when the joint opening is not observed. The frictions between the segments are the key factors for the bending moment and segment deformation control. The opening of the circumferential joint with an increase in the joint opening then becomes the primary control factor. The transfer ability becomes stable when the load continues increasing after mortise and tenon contact. Better transfer ability occurs with a general segment with four pairs of mortises and tenons. This was presented as a smaller value of an increasing rate and the stable magnitude of the joint opening. From the perspective of practical engineering, mortises and tenons can be added to the vault to increase the load and deformation transfer ability of the general segment after the loss of the longitudinal force.

Early risk prediction of diabetes could help doctors and patients to pay attention to the disease and intervene as soon as possible, which can effectively reduce the risk of complications. In this paper, a GA-stacking ensemble learning model is proposed to improve the accuracy of diabetes risk prediction. Firstly, genetic algorithms (GA) based on Decision Tree (DT) is used to select individuals with high adaptability, that is, a subset of attributes suitable for diabetes risk prediction. Secondly, the optimized convolutional neural network (CNN) and support vector machine (SVM) are used as the primary learners of stacking to learn attribute subsets, respectively. Then, the output of CNN and SVM is used as the input of the mate learner, the fully connected layer, for classification. Qingdao desensitization physical examination data from 1 January 2017 to 31 December 2019 is used, which includes body temperature, BMI, waist circumference, and other indicators that may be related to early diabetes. We compared the performance of GA-stacking with K-nearest neighbor (KNN), SVM, logistic regression (LR), Naive Bayes (NB), and CNN before and after adding GA through the average prediction time, accuracy, precision, sensitivity, specificity, and F1-score. Results show that prediction efficiency can be improved by adding GA. GA-stacking has higher prediction accuracy. Moreover, the strong generalization ability and high prediction efficiency of GA-stacking have also been verified on the early-stage diabetes risk prediction dataset published by UCI.

In this paper, we propose a fast interference spectral imaging system based on liquid crystal (LC) relaxation. The path delay of nematic LC during falling relaxation is used for the scanning of the optical path. Hyperspectral data can be obtained by Fourier transforming the data according to the path delay. The system can obtain two-dimensional spatial images of arbitrary wavelengths in the range of 300–1100 nm with a spectral resolution of 262 cm−1. Compared with conventional Fourier transform spectroscopy, the system can easily collect and integrate all valid information within 20 s. Based on the LC, controlling the optical path difference between two orthogonally polarized beams can avoid mechanical movement. Finally, the potential for application in contactless and rapid non-destructive optical component defect inspection is demonstrated.

There are a number of satellites working in the harsh space environment. The charged particles in space may strike the electron devices causing the undesired influences, such as soft errors in memory devices or permanent damage in hardware circuits. Aiming at reliability evaluation of very-large-scale integration circuits implemented in SRAM-based field programmable gate arrays, a fault injection platform is constructed based on the soft error mitigation controller in this study. The authors adopt a 16K-point fast Fourier transformation processor as the design under test (DUT) and inject errors into different positions. The effectiveness of this platform is varied by comparing the results of DUT with Golden data. Compared with the traditional reliability testing techniques, the fault injection method proposed in this study has the advantages of low cost, short test period and low resource consumption. Hence, the proposed fault injection design is suitable for circuits consuming huge resources and large number of repeating tests.

The fast Fourier transform FFT processor is an important part of the space real-time signal processing system based on field programmable gate array (FPGA). Since occupying a large amount of logical resources and storage resources, FFT processor is more vulnerable to high-energy particles in space, resulting in single event upset (SEU). This paper presents a novel FPGA scrubbing framework base on dynamic partial reconfiguration technique for a FFT processor to mitigate SEU. The proposed scheme is compared with the blind scrubbing, the reconfiguration time is reduced by 78%. Then, the resource utilisation is 61.5% less than triple modular redundancy scheme. This paper also presents a DPR controller for FFT processor, which is evaluated in terms of hardware resources and reconfiguration time. A comparison to the Xilinx PRC IP shows that multipath delay feedback FFT controller saves 38.6% resources.

With the development of synthetic aperture radar (SAR) technologies in recent years, the huge amount of remote sensing data bring challenges for high-speed transmission and real-time processing. The general platform with GPU, CPU or digital signal processor (DSP) cannot meet the requirement for short delay and low power. Therefore, a field-programmable gate array-digital signal processor (FPGA-DSP) SAR imaging accelerate platform has become a solution for processing performance with a lower latency and power. In this study, an effective mapping strategy is adopted to the FPGA-DSP hybrid heterogeneous architecture to accelerate the processing performance according to the analysis of Chirp Scaling SAR imaging algorithms. As a proof of concept, a FPGA-DSP hybrid heterogeneous accelerating platform is designed and realised. The platform requires 12 s to focus a stripmap SAR raw data with a granularity of 16,384 × 16,384.

This study presents a chirp scaling (CS) phase function generation scheme based on CORDIC algorithm, it adopts single precision floating-point CORDIC processor to implement a variety of non-linear operations which are involved in CS synthetic aperture radar (SAR) imaging algorithm. We extend the range of convergence of CORDIC algorithm and reduce the data width in rotation unit module by adopting a hardware resource reduction scheme. We also adopt a unified CORDIC processor to achieve square root, multiplication, and division operation, which can substitute multiple single-function processors and simplify the complicate arithmetic in CS algorithm. As a proof of concept, we verify the performance of the proposed design scheme on Xilinx XC7VX690T FPGA platform, it is also applied to 16384 × 16384 points target SAR imaging system, the FPGA resource occupancy of the CS phase function generation module demonstrates that the usage of CORDIC processor can effectively save the consumption of hardware resources, and the maximum operating frequency is acceptable. The accuracy of phase functions can satisfy the engineering requirements.

Automatic targets recognition (ATR) for synthetic aperture radar (SAR) image is very important. ATR can be used in traffic management, national frontier safety, and so on. Traditional algorithms for SAR ATR is composed of extraction features and training classifier. The features are essential for the classification accuracy. However, choosing good features by hand is a hard task. The deep convolutional neural networks (CNNs) which can learn features automatically have got a great performance in natural images. However, the CNNs have many parameters and need a lot of data to train such networks. The remote-sensing data of SAR is limited. Then, the authors need a simple network which needs not much data and easy to train. The principal component analysis network (PCANet) is a shallow network that performs well in the recognition task and needs no hand features choosing. Though this network has produced a wide application in the natural images, it is rarely used in the SAR images. The experimental result of the moving and stationary target acquisition and recognition (MSTAR) dataset shows that the PCANet can achieve over 99% accuracy on ten-class targets. This result is better than traditional algorithms and is very close to the results of deep-learning methods.

Sliding spotlight synthetic aperture radar (SAR) is a hot imaging mode in space-borne SAR. It can acquire high-resolution and large azimuth scene size simultaneously. The main challenges for sliding spotlight SAR processing in real time are the huge volume of raw data and complex imaging algorithm. The rapid development of the graphics processing units (GPUs) provides a new computing platform for high-performance SAR processing. This work presents a parallel processing of sliding spotlight SAR imaging algorithm on GPU via compute unified device architecture and tests the speedup of each module of the algorithm on the K20c GPU platform from the aspect of a small granularity and a large granularity of point target images. Compared with traditional CPU-based SAR imaging technology, the proposed GPU-based sliding spotlight SAR imaging obtains a speedup of 186.80 when processing data with a granularity of 16,384 × 8192 and gets a speedup of 49.72 when processing data with a granularity of 65,536 × 32,768, thereby greatly improving the real-time imaging processing.

Compared with the current mature point scanning metal additive manufacturing technology, the surface exposure technology by laser additive manufacturing can accelerate the construction speed, and the short pulse laser is expected to improve the resolution. Here, a surface exposure technology processing system was constructed based on a nanosecond pulsed laser source and an optically-addressed liquid crystal spatial light modulator with a damage threshold higher than 500 mJ/cm2. The resolution of the surface exposure processing system is proved to be about 100 μm.

In order to make video transmission more stable, various error-resilient mechanisms are proposed on video coding in the literature. However, the redundancy mechanism behind classical redundant coding algorithms is relatively simple and is not suitable for the network environment and video content in the context of screen content sequence with multiple abrupt frames and still frames. Motivated by this, a frame-level coding selection mechanism is proposed in this paper for the error-resilience transmission of screen content, where additional code stream or redundant information is considered to improve error-resilient performance with redundant coding and acceptable video quality is obtained in the case of frame transmission error. In addition, selective allocation redundancy is conducted to take the importance of the video frame ROI (region of interest) area into account in the co-encoding process. As a result, the redundancy insertion efficiency and the reliability are improved in return. The corresponding experiments validate the effectiveness of the schemes proposed in this paper.

This paper proposes a new level set method for topological shape optimization of continuum structure using radial basis function (RBF) and discrete wavelet transform (DWT). The boundary of the structure is implicitly represented as the zero level set of a higher-dimensional level set function. The interpolation of the implicit surface using RBF is introduced to decouple the spatial and temporal dependence of the level set function. In doing so, the Hamilton-Jacobi partial differential equation (PDE) that defines the motion of the level set function is transformed into an explicit parametric form, without requiring the direct solution of the complicated PDE using the finite difference method. Therefore, many more efficient gradient-based optimization algorithms can be applied to solve the optimization problem, via updating the expansion coefficients of the interpolant and then evolving the level set function and the boundary. Furthermore, the DWT is employed to handle the full matrix arising from the globally supported RBF interpolation. Several high stiffness but lightweight designs with smooth and clear structural boundaries are optimized and presented. The numerical results show that the proposed method can remarkably increase the efficiency in the topology optimization design of both the 2D and 3D structures.

Continuous and uniform carbon nanofilms (CNFs) are prepared by pyrolysis of polyimide films which are produced by molecular layer deposition (MLD). The film thickness can be easily controlled at nanometer scale by altering the cycle numbers. During the annealing process at 600 °C, the polyimide film is subject to shrinkage of 70% in thickness. The obtained CNFs do not exhibit a well-graphitized structure due to the low calcination temperature. No clear pore structures are observed in the produced films. CNFs grown on a glass substrate with a thickness of about 1.4 nm shows almost 98% optical transmittance in the visible spectrum range. Au nanoparticles coated with CNFs are produced by this method. Carbon nanotubes with uniform wall thickness are obtained using anodic aluminum oxide as a template by depositing polyimide films into its pores. Our results demonstrate that this method is very effective to coat conformal and uniform CNFs on various substrates, such as nanoparticles and porous templates, to produce functional composite nanomaterials.

The influence of driving conditions on the phase-modulation ability of an optically addressable spatial-light modulator (OASLM) is investigated using an equivalent circuit method and a system for measuring wave-front modulation that uses a phase-unwrapping data-processing method, and is constructed with a charge-coupled device and wave-front sensor. 1λ peak-to-valley phase change for a 1053 nm laser beam is acquired with the home-made OASLM at the optimal driving voltage of 14 V at 200 Hz. The detection system for wave-front modulation has a spatial resolution of 200 µm for binary images and a minimum distinguishable contrast of 1 mm. On-line phase modulation with feedback control can be acquired with the OASLM and the corresponding measuring system.

Using the traditional Ant Colony Algorithm for AGV path planning is easy to fall into the local optimal solution and lacking the capability of obstacle avoidance in the complex storage environment. In this paper, by constructing the MAKLINK undirected network routes and the heuristic function is optimized in the Ant Colony Algorithm, then the AGV path reaches the global optimal path and has the ability to avoid obstacles. According to research, the improved Ant Colony Algorithm proposed in this paper is superior to the traditional Ant Colony Algorithm in terms of convergence speed and the distance of optimal path planning.

In this paper, a finite element model of membrane air spring in the vehicle is established, and its vertical stiffness characteristics under a certain inflation pressure are analysed. The result of finite element simulation method is compared with the result of the air spring bench test. The accuracy and reliability of the finite element simulation method in nonlinear analysis of air spring system are verified. In addition, according to the finite element method, the influence of the installation of the air spring limit sleeve on its stiffness is verified.

Flake graphite was mechanically modified at different times in N-methyl pyrrolidone under normal pressure. The results of the scanning electron microscopy, X-ray diffraction, and transmission electron microscopy suggested that the structure of the flake graphite was modified. The crystallinity of the flake graphite, and many defects were introduced into the material. The evaluation of capacitor performance by cyclic voltammetry, galvanostatic charge/discharge tests, and electrochemical impedance spectroscopy was also performed. Results showed that the electrochemical performance of flake graphite was strongly enhanced, particularly when it was exfoliated for 6 h. Moreover, the electrochemical capacitive properties of activated carbon were obviously enhanced through the substitution of acetylene black by flake graphite modified for 6 h.

Due to their adverse health effects and their abundance in urban areas, diesel exhaust ultrafine particles caused by the aftertreatment devices have been of great concern in the past years. An experiment of particles number emissions was carried out on a high-pressure, common rail diesel engine with catalytic diesel particle filter (CDPF) to investigate the impact of CDPF on the number emission characteristics of particles. The results indicated that the conversion rates of CDPF is over 97%. The size distributions of particles are bimodal lognormal distributions downstream CDPF at 1400 r/min and 2300 r/min. CDPF has a lower conversion rates on the nucleation mode particles. The geometric number mean diameters of particles downstream CDPF is smaller than that upstream CDPF.

This paper presents a double frequency conductivity measurement method for measuring mine bursting water, to solve the capacitance effect of the conductivity sensor itself has the help. The core controller of the system is the single chip microcomputer ATMEGA128. This paper introduces the basic principle of the measurement of the existing problems and the dual frequency measurement method, and then introduces and analyzes the hardware. To test and analyze the collected data, the double frequency method is found to have good stability and accuracy in the measurement of the electrical conductivity of mine inrush water. It is proved that the method and the system design of the hardware circuit can accurately measure the electric conductivity of the mine inrush water source.

In this paper, a fibre Bragg grating (FBG) interrogation technique based on high Birefringence fibre loop mirror (Hi-Bi FLM) and wavelength division multiplexer (WDM) is proposed and demonstrated. The approximate linear edge of the transmittance of the Hi-Bi FLM, which is a sinusoidal function of wavelength, is used to interrogate the sensing FBGs and WDMs is used to realize wavelength discrimination .Suitable for both static and dynamic sensing, this interrogation method has the advantages of all fibre design and high stability.

Ti-Si-N nanocomposite films were prepared by co-sputtering Ti and Si targets in Ar/N2 gas atmosphere. The effect of N2 flow rate on the structure, adhesion strength and friction coefficient of the deposited films was studied by using X-ray diffraction, atom force microscope, field emission scanning electron microscopy and multi-functional tester for material surface properties. The Ti-Si-N films had a fine, smooth and compact structure with TiN nanograins embedded in an amorphous Si3N4 matrix. The nanocomposite films exhibited (200), (111), (220) and (222) reflections with a dominant orientation of the (200) reflection. When the N2 flow rate increased, the film structure was refined. It was found that both interfacial adhesion strength and friction coefficient depended on the N2 flow rate, and the best values were exhibited by the nanocomposite film produced at N2 flow rate of 15 sccm, perhaps contributed to a finer and smoother structure of this deposited film.

In-fissure divert fracturing technology, in which diverting agent is added. It can create new branch fractures and micro fractures, increase the area of fluid-release and achieve the goal of production and injection increase. This paper introduces a new diverting agent material with different kinds of petroleum resins. A series of evaluation including compatibility, efficiency and dissolved time was put forward. The results showed that the soluble rate of this agent is from 6 h to 12h and with increasing temperature and prolonging dissolved time, soluble rate reach 96% at 110° indicated good solubility. The critical flow velocity of sand production increases more than 30 ~ 60 times with adding fiber. The highest breakthrough pressure can reach 0.5MPa in 10 cm cores containing 9‰ diverting agent in the fracturing fluid. Meanwhile, it has minimal impact on flow conductivity .It had good flow back after treatment the viscosity was 13-54 mPa.s. Moreover, a special instrument was introduced to evaluate the performances of fracture conductivity and diverting. More than 24 treatments with this new material in X oil field have been performed with encouraging results with an average post-fracturing rate 11m3/d. It has great influences on new chemical material for improving complex fractures net-work of hydraulic fracturing in tight oil and gas reservoirs.

In this paper, models are build to evaluate the impact of the forest on the valley’s illumination. Based on the assumes that all the light reach the ground comes from the diffuse reflection which comes from the sun directly and from the diffuse reflection of other points, One model is build to consider the impact of time and latitude on the direction of the sunlight. So we can get the direction of the sunlight at different time and latitude through the model. Besides, this paper develops a illumination model to evaluate the intensity of illumination of the ground. Combining the models above, this paper get a complete model which can not only evaluate the overall light intensity of the valley but also convert the light intensity to the intensity of illumination. Simulation of the intensity illumination of some basic terrains and finally gives a comprehensive results which is practical and close to the common sense.

This paper has proposed a novel force rebalance control method for a MEMS gyroscope using ascending frequency drive and generalized PI control. Theoretical analyses of ascending frequency drive and force rebalance control methods are illustrated in detail. Experimental results demonstrate that the electrical anti-resonant peaks are located at the frequency responses in the RFD system, which seriously deteriorates the original response characteristics. However, they are eliminated in the AFD system, and the electrical coupling signal is also suppressed. Besides, as for the force rebalance control system, the phase margins approximate to 60deg, gain margins are larger than 13dB, and sensitivity margins are smaller than 3.2dB, which validates the control system is stable and robust. The bandwidth of the force rebalance control system is measured to be about 103.2Hz, which accords with the simulation result. The bias instability and angle random walk are evaluated to be 1.65deg/h and 0.06deg/√h, respectively, which achieves the tactical level.