造型粉流动性能对分步压装工艺的影响

为研究造型流动性对分步压装工艺适应性及其装药安全性的影响,测量了不同配方造型粉的流散性和堆积密度,通过分步压装工艺试验,研究炸药的流动性对分步压装工艺及其安全性的影响。结果显示,炸药的流散性在一定范围内才能适合分步压装工艺,降低炸药的流散性,可提高局部装药密度,但增加了径向密度差,降低了装药过程的安全性。在流散性适宜的条件下,分步压装装药密度随堆积密度的增加而增加。     

不同粘结剂制备的分步压装用炸药对撞击感度的影响

为研究粘结剂对分步压装装药过程产生热量的影响,设计了以高聚物和石蜡为粘结剂的2种分步压装炸药,分别测试了高聚物和石蜡的粘度,并对这2种炸药造型粉及药柱的撞击感度进行了研究。研究结果表明,采用高聚物做粘结剂制备的分步压装炸药在装药过程中产生的热量明显大于石蜡做粘结剂制备的分步压装炸药,即粘结剂类型对分步压装装药工艺的安全性具有重要影响。     

高聚物黏结粉末分步压装成型件性能研究

为获得高聚物黏结粉末分步压装成型技术条件,主要研究了工艺条件对分步压装成型件性能的影响,探索了分步压装成型技术特点。结果说明,分步压装成型界面清晰,无裂纹等质量缺陷,界面结合紧密;而采用一次成型的成型件成型界面比较弯曲、不规则;分步压装可以有效改善模压法一次成型的装药质量,解决模压法成型件的轴向密度均匀性问题,有效提高装药质量;分步压装的预成型压力值对成型件界面的影响非常重要,预成型压力值应为成型压力的45%～60%。     

压药工艺参数对成型药柱质量的影响研究

为解决弹药压装法技术中关键工艺参数的选择与控制问题,对影响药粒压制成型质量的因素进行研究.以PBX炸药为例,采用试验和仿真相结合的方法,结合炸药的特性,将PBX炸药粉末简化成有限个包覆有粘结剂的HMX球形颗粒,建立炸药体系的3维细观模型,对压药过程进行有限元仿真模拟,得出压力和保压时间对药柱质量产生影响的规律.结果表明:该研究可为弹药装药的研制与生产提供参考,具有一定的实用价值.     

含铝炸药装药工艺装备现状与发展趋势

铝粉具有较高氧化热、来源广泛等优点,用于含铝混合炸药,可大幅度提高炸药爆热。笔者对含铝炸药的各种装药方法的工艺与设备、国内外现状及发展趋势进行研究。介绍压装法(分步压装法)、浇注固化法以及双螺杆捏合柔性挤压法等装药技术,分析国内外现有技术,以及对固态含铝炸药压装药、含铝炸药浇注固化装药及含铝炸药双螺杆挤压装药的处理方法,并阐述了含铝炸药装药发展趋势,提出我国在该技术领域发展重点和措施的建议。该研究可为含铝炸药装药技术的发展提供参考。     

分步压装装药工艺参数对装药密度及密度分布的影响

用模拟药和可退模开合弹对不同分步压装装药工艺参数进行实验,并对装药密度和轴径向密度分布进行检测,分析分步压装工艺参数变化对最终装药密度和密度分布的影响。试验结果表明:随着螺杆直径的增大,周边和平均装药密度均呈上升的趋势;装药过程中初始压力越高,越有利于提高装药密度和密度分布,当压力达到一定值后,装药密度趋于一致;螺杆距弹体底部间距越小,底部越容易压实,密度越高;螺杆每次带入的进料量越少,压制次数越多,密度均匀性越高。该研究为加快分步压装装药工艺的推广应用打下了基础。     

压制密度及密度均匀性对装药撞击安全性的影响

为了研究装药密度对撞击安全性的影响,针对A-Ⅸ-Ⅱ炸药、B炸药、HMX基含铝炸药压制了不同密度的药柱.用A-Ⅸ-Ⅱ炸药压制了径向呈一定密度分布的药柱,利川400 kg落锤进行了撞击加载试验.结果显示,随着密度的增大,A-Ⅸ-Ⅱ炸药、B炸药、HMX基含铝炸药的起爆阈值增加.对于A-Ⅸ-Ⅱ炸药,当装药密度达到1.680 g...     

基于三维打印技术的纳米奥克托今与梯恩梯熔铸炸药制备及性能研究

为解决传统熔铸炸药缺陷多、密度低、力学性能差等问题,将三维(3D)打印技术应用到熔铸炸药的成型制备中。采用自主研发的熔铸炸药3D打印成型原理样机,通过筛选熔铸炸药配方、优化工艺参数,成功打印出含纳米奥克托今和梯恩梯的熔铸炸药药柱。对打印的药柱以及传统浇铸的药柱进行了微观结构、密度和均一性、抗压强度以及爆速等性能表征对比。结果表明：3D打印成型的药柱结构密实,密度为1.65 g/cm³,提高2.0%;抗压强度为5.56 MPa,提高273%;爆速为7 184 m/s,提高2.1%;综合性能明显优于传统浇铸成型的药柱。     

压力注装装药工艺在药柱生产中的应用

介绍了压力注装装药工艺的使用条件、理论依据、原理应发展情况。这种工艺可以提高大尺寸药柱的内在质量，药柱成型性好，而且密度分布均匀，工艺过程短。对改进装药工艺来讲，有一定的参考价值。     

一种大口径战斗部分步压装药有限元模拟与实验

为提高大口径弹药分步压装药效率,对某大口径战斗部分步压装药进行有限元模拟与实验。根据分步压装特点制定针对某大口径战斗部的分步压装工艺流程,采用ANSYS有限元模拟方法分析装药过程中弹壁与导爆管与变形受力情况,开展工艺试验制定工艺参数,采用相应的工艺参数进行大口径战斗部分步压装高能炸药。结果表明,装填结果完全满足××大口径战斗部的装药质量要求。     

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.     

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 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.     

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.