超细高氯酸铵复合粒子的制备及性能研究

为降低超细高氯酸铵(AP)的机械感度,以纳米石墨粉、普通石墨粉和炭黑为钝感改性剂,采用气流冲击粉碎法对超细AP进行表面改性,制备了超细AP/纳米石墨(AP-1)、超细AP/石墨(AP-2)、超细AP/炭黑(AP-3)复合粒子以及空白超细AP对比样(AP-C)。采用场发射扫描电子显微镜(SEM)、微米粒度仪、X射线粉末衍射仪(XRD)及傅里叶红外光谱仪(FTIR),表征了复合粒子的形貌和结构;用撞击感度仪和摩擦感度仪,测试对比了复合前后超细AP粒子的机械感度;采用差示扫描量热仪(DSC),测试了复合粒子的热分解性能。结果表明,相比于AP-C,AP-1、AP-2和AP-3的撞击感度分别降低了18.2%、21.2%和8.9%,AP-1、AP-2和AP-3的摩擦感度分别降低了12.5%、12.5%和8.3%,10℃·min-1的升温速率下,AP-1、AP-2和AP-3的高温分解峰分别提前了75.4,64.2℃和44.4℃。     

溶胶-凝胶法制备RDX/SiO2纳米复合含能材料

利用溶胶-凝胶法制备RDX纳米复合含能材料的干凝胶及气凝胶。采用透射电镜(TEM)和X射线衍射(XRD)对其形貌和晶体结构进行表征,测试了其热分解性能和撞击感度。结果表明,RDX含量为45%的RDX/SiO2纳米复合含能材料气凝胶的DSC分解峰温提前了15.4℃。SiO2凝胶基体可以降低RDX的撞击感度,并且随SiO2基体含量的增大降低幅度增大。     

CL-20/FOX-7基PBX的制备及其性能表征

为提高六硝基六氮杂异伍兹烷(CL?20)的安全性能,并保持其较高能量,以聚氨酯高聚物Estane为包覆剂,1,1?二氨基?2,2?二硝基乙烯(FOX?7)为含能降感成分,利用水悬浮包覆法制备了三种不同配比的CL?20/FOX?7基高聚物粘结炸药。采用扫描电子显微镜(SEM)、X射线衍射仪(XRD)、差示扫描量热仪(DSC)、撞击感度测试仪以及摩擦感度测试仪对样品的形貌结构、晶型、热分解特性以及样品的机械感度进行测试分析,用电测法对三种配比高聚物粘结炸药(PBX)爆速进行测试。结果表明,CL?20/FOX?7基炸药颗粒包覆效果较好,且CL?20和FOX?7均未发生转晶。三种CL?20/FOX?7基PBX表观活化能比细化CL?20分别提高了17.12,32.87 kJ·mol~(-1)和40.24 kJ·mol~(-1);活化焓(ΔH)较CL?20也明显提高;特性落高由细化CL?20的27.5 cm分别提高到58.3,56.5,54.2 cm。三种配比CL?20/FOX?7基PBX实测爆速分别为8474,8503,8577 mg·s~(-1),与PBXN?5相当,但特性落高较PBXN?5提升了48.5%以上,炸药安全性能明显提升。     

RDX基复合含能微球的制备及表征

以硝化棉(NC)为粘结剂、黑索今(RDX)为主体炸药,采用喷雾干燥法制备了RDX/NC超细复合含能微球,采用扫描电子显微镜(SEM)、X射线衍射仪(XRD)、差示扫描量热法(DSC)对其进行了表征及热分析,并与RDX原料进行了对比;对喷雾干燥法细化的RDX/NC和RDX、水悬浮法包覆的RDX/NC、溶剂非溶剂法细化的RDX、RDX原料的撞击感度分别进行了测试。结果表明,RDX/NC复合含能粒子与RDX原料相比,形貌从块状变为球形,粒径从50~200μm减小至0.5~7μm,晶型无变化,但X射线衍射峰明显弱化,活化能从200.11kJ·mol-1降至186.87kJ·mol-1,热爆炸临界温度从504.98K升至507.70K。喷雾干燥细化、球形化和复合的RDX/NC球形粒子的撞击感度降低显著。     

纳米碳酸锶/高氯酸铵复合粒子的制备及其撞击感度和热分解性能研究

利用超声辅助共沉淀法制备纳米碳酸锶（SrCO₃）,通过溶剂-非溶剂法制备纳米碳酸锶/高氯酸铵（SrCO₃/AP）复合粒子。采用透射电子显微镜、扫描电子显微镜、X射线粉末衍射仪(XRD)分别对纳米SrCO₃的形貌、粒径、晶型和纳米SrCO₃/AP复合粒子的复合效果进行表征。对纯AP和纳米SrCO₃含量分别为2%、4%、6%的SrCO₃/AP复合粒子进行撞击感度测试;采用差示扫描量热仪分别对纯AP、纳米SrCO₃/AP复合粒子和相同比例的纳米SrCO₃与AP的简单混合物进行热分析。通过马弗炉将纳米SrCO₃/AP复合粒子分别在350 ℃和500 ℃下煅烧1 h,对煅烧后的产物作XRD表征,研究纳米SrCO₃的作用机理。结果表明：采用超声辅助共沉淀法制备出的纳米SrCO₃为类球形,粒径在60 nm左右,晶型为斜方晶系;制备出的纳米SrCO₃/AP复合粒子中,微米级的AP表面均匀分布着纳米SrCO₃,纳米SrCO₃的加入会使AP的撞击感度增加;通过两种不同方式添加的纳米SrCO₃均能升高AP的高温分解峰温度,对AP的低温分解没有影响;与纳米SrCO₃和AP的简单混合物相比,纳米SrCO₃/AP复合粒子中AP的高温分解峰值温度升高6.02 ℃,将纳米SrCO₃与AP进行复合后可以提高纳米SrCO₃对AP高温分解的负催化作用。     

纳米六硝基六氮杂异伍兹烷与三氨基三硝基苯含能复合物的制备及性能研究

为提高六硝基六氮杂异伍兹烷（CL-20）的安全性能,通过一步球磨法制得CL-20与三氨基三硝基苯（CL-20/TATB）含能复合物。采用扫描电镜（SEM）、粉末X射线衍射（XRD）、红外光谱（FT-IR）、差示扫描量热法（DSC）对原料和含能复合物的性能进行表征,并进行撞击感度测试与分析。结果表明：制备的产物不是CL-20和TATB的简单物理混合,而是生成新的晶型;在SEM图中,与原料相比,CL-20/TATB含能复合物表面更加光滑,球形化效果明显,形貌呈规则的小颗粒状,粒度分布约在50~200 nm之间;在XRD图谱中,最终产物的主要衍射峰分布明显不同于原料和简单混合物的衍射峰,有新的衍射峰出现,说明最终产物中有新的晶型出现,同时由于粒径变小导致衍射峰谱带弥散且宽化;在CL-20/TATB含能复合物的FT-IR图中,由于CL-20（—NO₂或—CH） 和TATB（—NO₂或—NH₂）之间的氢键作用,导致红外谱峰发生偏移;在DSC图中,CL-20/TATB含 能复合物的放热峰比原料CL-20和原料TATB的都提前,说明CL-20/TATB含能复合物的热分解活性比原料CL-20和原料TATB有所增强;撞击感度测试中,CL-20/TATB含能复合物的特性落高比CL-20高62 cm,具有更好的撞击安全性能。     

新型HMX/AP/EP纳米复合物的制备及表征（英文）

以含能聚合物(EP)为基底通过共沉淀法制备了奥克托今(HMX)/高氯酸铵(AP)/含能聚合物(EP)纳米复合物。用扫描电镜(SEM),能量色散X射线能谱(EDS)、比表面积(Brunauer-Emmett-Teller(BET))测定、红外(IR)光谱法和差示扫描量热法(DSC)表征了它的结构及性能。结果表明,HMX/AP/EP纳米复合物具有三维纳米网状结构。HMX和AP均匀沉积在EP上面,其尺寸为50~200 nm。HMX、AP和EP紧密结合在一起,具有良好的相容性。HMX/AP/EP纳米复合物的分解温度远低于HMX的。当HMX/AP/EP纳米复合物的氧平衡为零时,其分解热高达2570 J·g-1。HMX/AP/EP纳米复合物的撞击特性落高H50为50.49 cm,与HMX的撞击感度的特性落高(27 cm)相比,其机械感度较低。     

新型HMX/AP/EP纳米复合物的制备及表征（英）

以含能聚合物(EP)为基底通过共沉淀法制备了奥克托今(HMX)/高氯酸铵(AP)/含能聚合物(EP)纳米复合物。用扫描电镜(SEM),能量色散X射线能谱(EDS)、比表面积(Brunauer-Emmett-Teller(BET))测定、红外(IR)光谱法和差示扫描量热法(DSC)表征了它的结构及性能。结果表明,HMX/AP/EP纳米复合物具有三维纳米网状结构。HMX和AP均匀沉积在EP上面,其尺寸为50~200 nm。HMX、AP和EP紧密结合在一起,具有良好的相容性。HMX/AP/EP纳米复合物的分解温度远低于HMX的。当HMX/AP/EP纳米复合物的氧平衡为零时,其分解热高达2570 J·g^-1。HMX/AP/EP纳米复合物的撞击特性落高H₅₀为50.49 cm,与HMX的撞击感度的特性落高(27 cm)相比,其机械感度较低。     

基于气流粉碎法的超细类球形高氯酸铵批量制备及其表征

利用经过改进的气流粉碎机直接制备了超细类球形高氯酸铵(AP)粒子,通过扫描电子显微镜、激光干法粒度仪、傅里叶红外光谱仪和X射线衍射仪表征了原料AP、超细非球形AP和超细类球形AP 的形貌、粒度、样品成分和晶体结构。对同粒度超细类球形AP与非球形AP粒子的热分解性能、机械感度、堆积密度、吸湿性与结块性进行了测试。结果表明,利用气流粉碎法直接制备的超细AP粒子基本为类球形,粒度大约2 μm,粒度均匀,表面光滑无缺陷,且分散性良好,过程无杂质引入。球形化后AP粒子相比同粒度非球形AP粒子：热稳定性略微提高,撞击感度降低37.6%,摩擦感度降低26.7%;松装堆积密度提高了10.7%,振实密度提高了24%;吸湿与结块性明显改善。     

超细高氯酸铵(AP)微观结构对机械感度的影响

采用机械研磨法细化高氯酸铵(AP),采用扫描电镜(SEM)、X射线衍射(XRD)、撞击和摩擦感度试验方法研究不同状态AP粒子的微观结构和机械感度.结果表明:超细AP样品的机械感度受到多种微纳结构因素的共同影响,多种因素差异使超细AP样品的撞击感度和摩擦感度表现出与某单个因素间不存在必然联系,各因素对撞击感度和摩擦感度的影响程度不同也使各超细AP样品的撞击感度和摩擦感度表现出不一致的顺序;并用热点理论分析了超细AP微观结构对机械感度的影响.     

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.