Applied Mechanics and Materials Vols. 347-350

Abstract: Fresh vegetable logistics is an important part of agricultural product logistics in our country, but the unique characteristics of fresh vegetables, fresh time for vegetable logistics requirements is strong. therefore, the logistics mode selection of fresh vegetables is particularly important, several modes of vegetable logistics,are analyzed in detail in this paper, and provide some reference for the fresh vegetable logistics mode select.

Abstract: In order to solve the contradiction of pulse radar detection range and range resolution, the LFM signal which has a large time-bandwidth product is chosen to be modulated on the transmitter pulse. So that the radar has larger width and higher range resolution. Since the conversion of the transceiver switches, wide LFM signal may cause close range blind spots. Timeshare launching one long and one short signals is traditional solution, but it will cause a lower data rate. A kind of dual-LFM signal based on frequency division multiplexing is presented, the short pulse is used in short-range to offset the lack of wide LFM signal. Through simulation, it is guaranteed that, by using this kind of signal, the radar has a higher resolution regardless of the target distance, and the short-range blind spot also can be eliminated.

Abstract: Based on the geometrical projection of 3D scattering centers on the line of radar sight, a new method of bistatic inverse synthetic aperture radar 3D Imaging is proposed. In the method, Range-Doppler algorithm gives a sequence of 2D images of target during its motion, and 3D reconstruction of target geometry is completed by the factorization method. We analyzed the theory of Bi-ISAR 3D imaging, deduced the process of the factorization method, and introduced the hierarchical reconstruction model. The simulation verified the validity of the paper.

Abstract: Decoying technology is an effective mean to antagonize anti-radiation missile. Building models and simulation has become a necessary way to study the effect of decoying system. Realization of decoying principal and arrangement of critical factors influence the decoying effect directly. Definition of critical resolution angle and principal of choosing radiation source are analyzed to study their influence on decoying effect. They are also redefined in this paper. Models are built and simulated to study critical resolution angle and overload coefficient influence on decoying effect. And their relationships with decoying success rate are acquired in the end.

Abstract: A range profile synthetic algorithm of the stepped-frequency chirp train waveform is designed to obtain HRRP (High Resolution Range Profile) in this paper. Based on waveform model, grating lobes restraining method is proposed with the help of autocorrelation function. Due to the matched filter operation, image energy spill over the close range bins, which causes “ghost images”. Set parameters of inner pulse bandwidth, stepped frequency and chirp compression envelop sampling frequency properly, and then carry the synthetic algorithm, the “ghost images” are restrained. All of the results are validated by simulation.

Abstract: Front-end intercept probability of reconnaissance equipment is a significant evaluation index of radar reconnaissance system. It shows the ability of discovering and detecting radar signal in the front of reconnaissance equipment. In order to obtain the relatively authentic intercept probability, first, rules of intercept judgment are elaborated. Then front-end interception is devised through the reconnaissance equipment functional simulation. Finally, intercept probability is calculated in Monte-Carlo simulation, and an application verification is realized. The result indicates the method of intercept probability computation is feasible and has certain application.

Abstract: For testing the quality of radar echo propagation, the reverberating chamber electromagnetic environment is classified, the quality of radar echo propagation environment emulation is estimated by the parameter S, the Rice factor K is compared with the parameter S, the test result illustrates that the reverberating chamber can be used as emulator of radar echo propagation environment and as emulator of the base of radar electromagnetic environment.

Abstract: In order to raise the train effect of radar operation efficiently, offer detailed, accurate, visual task situation information, high limit decreases or eliminates to train distorted and operating fault. The paper have put forward a kind of based on GDI + graph display function and USB data communication display the realization method of controlling terminal, Have realized for radar display relatively lifelike imitate, The interface that imitated has included actual radar, is major to display essential factor.

Abstract: The temperature and thermal stress distribution on BK7 glass was numerical simulated by MATLAB according to heat conduction theory. Research has shown that the laser pulse number, spot radius and pulse width can change the extent of the damage threshold for BK7 glass. The results shown the damage threshold decreased with the laser pulse number and radius increasing. The laser power also increased with the pulse width reducing. At the same time, the damage threshold was corresponding reduced.

Abstract: In the field of electric vehicles, the high power density demand for the permanent magnet synchronous motor (PMSM) has made the thermal management a great challenge, especially the end winding. For enhance the heat dissipation for end winding, Aluminum Nitride (AlN) potting compound is introduced. Numerical simulation is performed in this paper to evaluation the effect of usage of potting compound. A prototype motor is built up with the end winding filling with the proposed potting material. Experiment shows that the heat dissipation has improved compared with the baseline motor.