Abstract:在虚晶近似框架上用刚性离子模型计算了铁电固溶体PbZrxTi1-xO3(x=0.25-0.40）布里渊区Γ点的声子振动频率，结果显示，随着Zr组份x的增加，光学横模向低频方向移动，与已有的Raman实验相符。

Abstract:An estimation method of the nonlinear residual frequency errors for frequency modulation in LFMCW radar was proposed based on zero crossing detection and periodogram,and analysis of the zero crossing detection errors in phase modulation sinusoid signal was given in details.Simulations demonstrate that this method provides an accurate estimation of nonlinear residual frequency errors with high computation efficiency.An experimental result was also given.

Abstract:In consideration of the thickness and the relativistic effect of the hollow electron beam, the hot dispersion relation including the electron beam space charge effect for the ring plane traveling wave tube was derived by making use of the Ritz Galerkin method and combining with the field matching method. The numerical results given were in terms of the small signal gain curve. Finally, the influences of the radius and current of the electron beam, the acceleration voltage and the geometrical dimensions of the slow wave structure on the small signal gain were discussed. The results presented in this paper provide theoretical basis on designing the millimeter wave ring plane traveling wave tube.

Abstract:This paper describes a real time IR image track system implemented with COTS multiprocessors. The implementation of a real time IR image processing algorithm onto the processors is discussed. The architecture of the hardware and software of the system was described, too. The use of programmable image processing of the system provides increased adaptability to higher performance robust algorithms and flexibility for future modification. It is proved by the experiment that the system has good ability of tracking multiple targets

Abstract:Based on the energy function optimization theory of the artificial neural network,a theoretical frame of neural network algorithm was presented to produce 1 D range profile of MMW stepped frequency radar and some simulation experiments were done.Because of the parallel computation of the neural network,the method developed by the authors has the advantage of rapidness.

Abstract:Land surface temperature(LST) and NDVI were used for classification and soil water content(SWC) regression. Firstly, the 6 kinds of targets, dense wheat, sparse wheat, naked soil, water in ponds, silt and aquatic plants, were well classified using LST and NDVI channels. Secondly, the triangle shaped scatter plot was built and analyzed using LST and NDVI channels. Compared with the scatter plot built by red and near infrared bands, the spectral distances between different clatssifications are larger, and the samples in the same classification are more convergent. Finally, a VIT model was presented to extract SWC using LST and NDVI channel, which predicts the moisture well. The mapping of soil's moisture in the wheat area was calculated and illustrated for scientific irrigation and precise agriculture.

Abstract:A new method of segmenting head and shoulder object was presented by using the bi motion model, which is better in describing such objects' motion than single motion model. An algorithm was developed to estimate the model parameter and implemented in an semi automatic segmentation system. The simulated result reveals that the segmentation system using the authors' bi motion model can segment head and shoulder object more accurately.

Abstract:The 1 D and 2 D photonic band gap(PBG) structure used in microstrip was studied by using FDTD technique. Several PBG circuits were fabricated for comparing the calculational results with experimental ones. The effects on the stopband formed by PBG structure were analyzed detailedly, which brought form the length and numbers of period of PBG structure, unit's size and shape, etc., and conclusions were given.

Abstract:The temperature dependence of gain in InGaAs multi stacked quantum dots (QDs) laser was investigated and compared with InGaAs single quantum well(SQW) laser. It was found that quantum dost laser showed a much better stability of gain on temperature. The gain in InGaAs QDs increases with temperature in the region from 140K to 200K. Beyond 200K the gain decreases with increasing temperature. The mechanism for the above gain characteristics was analyzed. The gain peak wavelength moves to longer wavelength range with increasing temperature and exhitits a better temperature stability compared with quantum well laser.

Abstract:Mode selection of a moderate power gyrotron operating at the ISM frequency and the second harmonic is discussed in detail. By analysis and calculation for electron beam wave coupling, mode competition, voltage depression and limiting current, and ohmic losses, considering the compactness of the configuration, the result obtained is that TE 31 mode is probably a best choice for the technology gyrotron operating at the ISM frequency.

Abstract:类比信息传递过程中的一般测不准关系式 ,引进表征问题复杂性的函数复相关系数R和代表网络结构特性的隐节点数h ,揭示了BP网络过拟合现象出现时的网络学习能力与推广能力之间满足的不确定关系式 ;通过模拟了 12种不同类型复杂程度函数的过拟合数值试验 ,确定出关系式中的过拟合参数 p的取值范围已缩小为 1×10 -5～ 5× 10 -4;给出应用BP网络对给定样本集的训练过程中 ,判断出现过拟合现象的方法

Abstract:The results, albumen thermo solidification experiment and leaking dynamometer are used to investigate the radiant power density field radiated from a microwave antenna, show that the microwave field radiated from the monopole antennas, which are used usually in clinical treatments now, is not uniform. The radiation intensity near the root part of the antenna is strong,and near the top part, which is close to affected part, is rather weak. The suggests that monopole antenna was inefficient and was not ideal as a microwave antenna for in body. For the helical antenna, however near the top part the radiation intensity was rather strong, and the radiation was concentrative and efficient. Experiment results and many clinical examples suggest that the helical microwave antenna is a dependable, stable, safe and efficient one, and has a wide applicant future in clinical practice.

Abstract:A 3 mm band IF switch radiometer was proposed.On the basis of discussing the theory as well as circuit structure and features,the performance of experimental prototype was presented.The research and experiment results show that not only its stability is better than that of total power radiomenter,but its cost and size are just similar to the latter because of absence of 3 mm band switch.It can surely meet the need of practical use.

Abstract:A new unsupervised multiresolution edge detection technique was presented,which combines the morphological filtering,pyramid data structure and fuzzy technique.The algorithm first constructed a pyramid by morphological filtering,then it considered the parent child linking relationship of edge nodes between the two adjacent levels as fuzzy model.Via this model,the coarse and low resolution edge map was propagated and refined in the pyramid,thus the map with fine and high resolution edge was obtained.Finally,some experiments on synthetic and real world images were given with satisfactory results.

Abstract:A 8mm band MMIC direct detection receiver was proposed on the background of bomb borne MMW radiometer. On the basis of the working principle of this system, main parameters of the system were analyzed and designed. Principle experimental results show that the radiometer has favorable performances, such as high sensitivity and small volume.

Abstract:以Bi(NO3 ) 3 ·5H2 O和Ti(OC4H9) 4 )为原料 ,采用化学溶液分解法 (CSD)成功地合成了Bi4Ti3 O12 纳米晶体材料 .这些纳米晶经过X 射线衍射 (XRD)和透射电子显微镜 (TEM )的初步研究 ,观察到了层状结构的Bi4Ti3 O12 ,并发现了Bi4Ti3 O12 纳米晶体具有棒状结构

Abstract:A recognition method of radar target was presented by using multi transform. First, target 1 D range profile was obtained by FFT. Then the Mahalanobis range of 1 D range profile was calculated. Then the target characteristics were extracted by wavelet transform, in which the data of Mahalanobis range were compressed. The experiments of recognition using the data of three kinds of aircraft models were performed. It demonstrates that the method has high recognition rate.