静拉伸载荷下93W合金缺口效应和断裂特征研究

研究了９３Ｗ－４．５Ｎｉ－２．５Ｆｅ合金在静拉伸载荷下的缺口效应，并用光学显微镜和扫描电镜观察分析了其变形和断裂特征。研究表明，９３Ｗ合金具有较小的缺口敏感性；缺口试样的变形和断裂与试样的形状有关，而光滑试样的变形和断裂则主要取决于合金微观组织的分布和均匀性。     

静拉伸载荷下93W合金制品效应和断裂特征研究

研究了９３Ｗ－４．５Ｎｉ－２．５Ｆｅ合金在静拉伸载荷下的缺口效应，并用光学显微镜和扫描电镜观察分析了其变形和断裂特征。研究表明，９３Ｗ合金具有较小的缺口敏感性；缺口试样的变形和断与试样的形状有关，而光滑试样的变形和断裂则主要取决于合金微组织的分布和均匀性。     

W－Ni－Fe－Co系重合金中锰的作用机制的研究

通过Ｍｎ的加入量的变化对９３Ｗ－Ｎｉ－Ｆｅ－Ｃｏ合金力学性能的影响，以及对合金中钨颗粒和粘结相的组成与含量，合金的显微及断口形貌，Ｍｎ及Ｏ、Ｓ的分布状态及它们间所形成夹杂物的类型、结构、尺寸、形态和分布等的系统研究，探讨了Ｍｎ在Ｗ－Ｎｉ－Ｆｅ－Ｃｏ系重合金中的作用及其机制。     

离心喷射沉积 Ti-48Al-2Mn-2Nb 合金的拉压性能

为了研究合金化和制备工艺对ＴｉＡｌ合金性能的影响，采用一种最新的真空离心喷射沉积成形技术制备了Ｔｉ－４８Ａｌ－２Ｍｎ－２Ｎｂ合金，研究了合金的室温拉伸和压缩性能以及显微组织的影响。结果表明，离心喷射沉积成形合金的屈服强度为２５１ＭＰａ，抗拉强度为３０５ＭＰａ，延伸率为２．８％。压缩屈服强度为４８８ＭＰａ，抗压强度为２２１０ＭＰａ，压缩率为３３．９％。离心喷射沉积成形Ｔｉ－４８Ａｌ－２Ｍｎ－２Ｎｂ合金组织呈层片状组织结构，并且含有孔隙，定量分析结果表明孔隙率约２％。文中对离心喷射沉积成形Ｔｉ－４８Ａｌ－２Ｍｎ－２Ｎｂ合金层片状组织的变形和断裂特征进行了分析。     

锌铝共晶合金超塑态的研究

研究锌铝共晶合金的超塑态。试验表明，在轧制状态下，合金具有变形纤维组织，对超塑性变形有利，不需进行特殊的超细化处理，可直接进行超塑性成形。探讨了显微组织、超塑性性能与变形制度间的关系，从而为制定和调整生产工艺提供了理论指导。     

用微量钪合金化的新型铝合金

用微量钪合金化的铝合金是新一代航天航空用结构材料。采用铸锭冶金法制备了该类Ａｌ－５Ｍｇ－（０．１０～０．３０）Ｓｃ－（０．０５～０．１５）Ｚｒ合金板材，测试了其不同状态下的拉伸力学性能σｂ、σ０．２和δ，采用金相显微镜和透射电镜观察分析了其不同状态下的显微组织结构。结果表明，该合金具有良好的强塑性，比不含钪的传统Ａｌ－５Ｍｇ合金强度提高了近７０～１５０ＭＰａ；微量Ｓｃ的添加显著细化了合金铸态的晶料尺寸和抑制了合金变形组织的再结晶，对合金起到了细晶强化和亚结构强化作用。     

（W＋CeO2）p／2024A1复合材料锻造性能研究

采用粉末热压工艺制成的（W＋CeO2）p／2024A1复合材料作为坯料，对这种复合材料进行锻造性能研究。详细描述55％和78％锻造变形量的复合材料的显微组织形貌，研究不同锻造变形量时复合材料的力学性能和断裂机制。研究分析表明，经过锻造复合材料内部组织致密、颗粒分布比较均匀，具有较高的力学性能。锻造变形量不同，复合材料内部的组织结构不同，导致材料的力学性能相差很大，材料的断裂方式也不同。变形量55％的复合材料显示出明显的韧性断裂，当变形量达到78％时呈脆性断裂。     

等通道角挤压对Mg-0.6%Zr合金力学性能和阻尼性能的影响

采用金相组织分析、显微硬度测试和DMA阻尼技术研究等通道角挤压对铸造Mg-0.6%Zr合金(质量分数)结构与性能的影响。研究结果表明,Mg-0.6%Zr合金经过ECAP变形时,发生了动态再结晶,晶粒显著细化,并随挤压温度的升高发生晶粒长大;变形后合金的室温力学性能明显改善,与铸态合金相比,显微硬度和拉伸强度均随挤压道次(1、2、4、6)的增加而增加,且合金经400℃挤压一道次后的阻尼性能优于铸态合金。     

K403镍基高温合金的高温拉伸断裂行为

利用Gleeble-1500热模拟试验机研究镍基高温合金K403在应变速率为0.01~10 s-1、温度为850~1 000℃条件下的高温拉伸变形行为,利用光学显微镜、扫描电镜、透射电镜等手段,分析拉伸变形后的显微组织及高温断裂机制。结果表明:随应变速率的增大,合金的峰值应力和断裂应力增大,断面收缩率和断裂应变则减小;而随变形温度的升高,合金的峰值应力和断裂应力降低,断面收缩率和断裂应变增大;850℃拉伸后变形组织中存在大量的位错胞状结构,随着变形温度的升高,变形组织中的位错密度减小;拉伸断口呈枝晶组织断裂特征,随着变形温度的升高,合金断裂方式由准解理断裂向沿晶断裂转变。     

锻造ZQAl9－4铝青铜合金裂纹分析

高强铝青铜合金因具有良好的物理性能和机械性能，广泛应用于民用和军工行业．本文中研究分析了ZQAl9-4高强铝青铜合金在锻造过程中出现的断裂进行了失效分析．通过宏观断口分析和显微组织微观分析表明零件的断裂主要是由于变形应力超过了合金的屈服极限和K相形成了裂纹源的缘故，使其发生了沿晶脆性断裂．     

Stability of the Third Generation Intensifier under Illumination

The stability under illumination of transmission-mode GaAs photocathode sealed in the third generation intensifier is investigated by use of spectral response testing instruments. The variations of spectral response with the illumination times under weak and intense illumination are compared. The variations of photoemission performance parameters are also characterized. The results show that during initial several weak illuminations photocathode behaves no evident decay and a maximum sensitivity is achieved, while under intense illumination the sensitivity of photocathode begin to decrease largely at the first illumination. The calculated performance parameters show that the variation of surface escape probability with illumination times is a direct cause of instability of photocathode. It is also found that under intense illumination peak wavelength is moved towards short-wave and peak response is decreased, which shows that the ability of long-wave response of photocathode is decreased.     

Passive Acoustic Radar for Detecting Supersonic Cruise Missile

A Passive Acoustic Radar is presented as a necessary complement to electromagnetic wave radar, which will be expected to be an effective means for detecting cruise missiles. Acoustic characteristics of supersonic flying projectiles with diverse shapes are expounded via experiment. It is pointed out that simulation experiment could be implemented using bullet or shell instead of cruise missile. Based on theoretical analysis and experiment, the ““acoustic fingerprint““ character of cruise missile is illustrated to identify it in a strong noise environment. After establishing a locating mathematical model, the technique of acoustic embattling is utilized to resolve a problem of confirming the time of early-warning, considering the fact that velocity of sound is much slower than that of light. Thereby, a whole system of passive acoustic radar for detecting supersonic cruise missile is formed.     

Design and Analysis of Test Schemes of Static Postponing Time on Shrapnels Used to Riot Control

The test scheme of static postponing time given in our actual national military test standard on shrapnels used to control riot is a nine-point test scheme on the combined action of three kinds of temperatures and three kinds of pressures,the consumed ammunitions are more excessive. Statistic analysis and tentative checkout about a lot of test data are done,feasibility gists are put forward for optimizing of the test design scheme. The optimizing design and data analysis of test scheme of the item are done by managing uniformity design theory, two scientific and reasonable six-point test schemes are confirmed. The feasibility and reliability of the optimizing design schemes put forward above are proved ulteriorly by test validating. The gained schemes not only have good design uniformity and little ammunition wastage and meet the test demand, but also have better forecast ability for the result data of other points using the mathematic models from the actual test points.     

Super-resolution Restoration of Remote-sensing Images

A novel image restoration scheme, which is super-resolution image restoration algorithm Poisson-maximum-afterword-probability based on Markvo constraint （MPMAP） combined with evaluating image detail parameter D, has been proposed. The advantage of super-resolution algorithm MPMAP incorporated with parameter D lies in the fact that superresolution algorithm MPMAP model is discrete, which is in accordance with remote-sensing imaging model, and the algorithm MPMAP is proved applicable to linear and non-linear imaging models with a unique solution when noise is not severe. According to simulation experiments for practical images, super-resolution algorithm MPMAP can retain image details better than most of traditional restoration methods; at the same time, the proposed parameter D can help to identify real point spread function （PSF） value of degradation process. Processing result of practical remote-sensing images by MPMAP combined with parameter D are given, it illustrates that MPMAP restoration scheme combined PSF estimation has a better restoration result than that of Photoshop processing, based on the same original images. It is proved that the proposed scheme is helpful to offset the lack of resolution of the original remote-sensing images and has its extensive application foreground.     

Design and Simulation of TF and TA Controller for Missile

A nonlinear terrain following(TF) and terrain avoidance(TA) controller is proposed for missile control systems. Based on classical TF algorithm (adaptive angle method), a new method for TF controller is proposed by using angle of attack. A method of obtaining terrain outline data from digital elevation map (DEM) for TF control is discussed in order to save store space. A TA algorithm is proposed by using bank-to-turn technique. The block control model, which is suitable for backstepping design, is given for nonlinear model of missile. Making full use of the characteristics of the system and combining block control principle and backstepping technique, a robust controller design method is proposed. Uncertainties in every sub-block are allowed, and can be canceled by using the idea of nonlinear damping. It is proved that the state tracking errors are converged to a neighborhood of the origin exponentially. Finally, nonlinear six-degree-of-freedom simulation results for the missile model are presented to demonstrate the effectiveness of the proposed control law.     

Design of Non-fragile Satisfactory Estimator for Linear Continuous Perturbed Stochastic Systems

The design problem of non-fragile estimator is addressed for a class of perturbed linear continuous systems. The perturbations occur on the plant and estimator parameters. The estimator designed should force the error system to achieve the desired decay rate and force the steady error variance less than the specified upper bound irrdevancy of the admissible plant perturbations and estimator perturbations. Consistency problem of the decay rate with the variance upper bound is first considered via linear matrix inequality （LMI） approach. The solution of the estimator parameter under specifications to be consistent is then discussed. The consistency condition of specifications and estimator parameter solution are transformed to feasible or minimum problems subject to a set of LMI respectively. The method is illustrated by a numerical example.     

An Improved Scene-based Nonuniformity Correction Algorithm for Infrared Focal Plane Arrays Using Neural Networks

The improved scene-based adaptive nonuniformity correction （NUC） algorithms using a neural network （NNT） approach for infrared image sequences are presented and analyzed. The retlna-like neural networks using steepest descent model was the first proposed infrared focal plane arrays （IRFPA） nonuniformity compensation method, which can perform parameter estimation of the sensors over time on a frame by frame basis. To increase the strength and the robustness of the NNT algorithm and to avoid the presence of ghosting artifacts, some optimization techniques, including momentum term, regularization factor and adaptive learning rate, were executed in the parameter learning process. In this paper, the local median filtering result of Xij （ n ） is proposed as an alternative value of desired network output of neuron Xij （ n ）, denoted as Tij （ n ）, which is the local spatial average of Xij （ n ） in traditional NNT methods. Noticeably, the NUC algorithm is inter-frame adaptive in nature and does not rely on any statistical assumptions on the scene data in the image sequence. Applications of this algorithm to the simulated video sequences and real infrared data taken with PV320 show that the correction results of image sequence are better than that of using original NNT approach, especially for the short-time image sequences （several hundred frames） subjected to the dense impulse noises with a number of dead or saturated pixels.     

Piecewise Filter of Infrared Image Based on Moment Theory

The disadvantages of IR images mostly include high noise, blurry edge and so on. The characteristics make the existent smoothing methods ineffective in preserving edge, To solve this problem, a piecewise moment filter （PMF） is put forward. By using moment and piecewise linear theory, the filter can preserve edge. Based on the statistical model of random noise, a related-coefficient method is presented to estimate the variance of noise. The edge region and model are then detected by the estimated variance. The expectation of first-order derivatives is used in getting the reliable offset of edge. At last, a fast moment filter of double-stair edge model is used to gain the piecewise smoothing results and reduce the calculation. The experimental result shows that the new method has a better capability than other methods in suppressing noise and preserving edge.     

Bistatic Sonar Localization Based on Best Linear Unbiased Estimation

A best linear unbiased estimation （BLUE） algorithm for bistatic sonar localization is proposed. The Cramer-Rao bound for bistatic Sonar and the geometrical dilution of precision （GDOP） in different conditions are given. The simulation results show that the location accuracy of BLUE algorithm is higher than the weighted least square method.     

Research on Gear-broken Fault Diagnosis in a Tank Gearbox

A fault diagnosis method of working position gear in a tank gearbox is put forward based on simulating the fault of working position gear in an actual tank, extracting the envelope of vibration signal by Hilbert transformation amplitude demodulation method, and zooming the low-frequency band to envelope signal.