喷雾结晶法制备高堆积密度球形硝基胍

为了提高硝基胍(NQ)的堆积密度和流散性,以N-甲基吡咯烷酮作为NQ的溶剂,无水乙醇作为非溶剂,六水硝酸镍作为晶型控制剂,采用喷雾结晶法制备了球形硝基胍晶体。单因素法确定制备高堆积密度球形NQ的最优工艺条件为:室温,溶剂与非溶剂体积比为1∶10,晶型控制剂质量分数为0.5%,喷雾压力为0.6 MPa,超声频率为40 Hz,搅拌速度为450 r·min~(-1),喷雾完毕继续超声震荡搅拌20 min。用标准容器法、扫描电子显微镜(SEM)、差热扫描量热法(DSC)和X-射线衍射仪(XRD)对最优球形NQ进行分析。结果表明:制备的NQ呈球形,堆积密度为1.232 g·cm~(-3),较原料NQ提高0.943 g·cm~(-3),DSC测得分解温度为258.71℃,较原料NQ提高8.03℃。     

1,2-二硝基胍的合成及热性能

以硝基胍(NQ)为原料、100%硝酸/20%发烟硫酸/硝酸铵为硝化体系,经硝化反应合成了1,2-二硝基胍(DNG)。用IR、¹H NMR、¹³C NMR、MS表征了DNG的结构。研究了影响DNG产率和正交实验的因素。用TG和 DSC研究了DNG的热分解行为。结果表明,硝化反应的优化条件为n(HNO₃)n(NQ)n(NH₄NO₃)=15 2 1,V(H₂SO₄)V(HNO₃)=1.25 1,反应时间为8 h,反应温度为10 ℃。优化条件下DNG产率达61.76%。DNG的 DSC曲线峰温为182.83 ℃,显示DNG有良好的热稳定性。     

DNP/DNTF低共熔物的二元相图及熔融动力学

为获得3,4-二硝基吡唑(DNP)/3,4-二硝基呋咱基氧化呋咱(DNTF)二元混合体系的相图,深入了解其低共熔物的熔融过程,采用差示扫描量热法(DSC)研究了不同比例的DNP/DNTF混合体系的液化及熔融过程,建立了液化温度Tl与组成x的T-x相图、熔融焓ΔH与组成x的H-x相图;研究了不同升温速率5,10,15,20℃·min^-1,不同添加剂奥克托今(HMX)、高氯酸铵(AP)和硝基胍(NQ)对低共熔物熔融过程的影响;通过Kissinger方程和?atava-?esták方程计算得到了低共熔物熔融过程的动力学参数活化能Ea、指前因子A和最概然机理函数。结果表明,从T-x相图得到的DNP/DNTF低共熔物的质量百分比为70.38/29.62,低共熔温度为76.38℃;由H?x相图得到的低共熔物组成为70.57/29.43。随升温速率的升高,熔融反应的开始温度和峰温延迟;HMX和NQ的加入使低共熔物的熔点明显后移,AP的加入对熔点影响不大。DNP/DNTF低共熔物的熔融动力学参数Ea和A为19.13 kJ·mol^-1和109.74 s^-1,最概然机理函数的积分形式为:G(α)=(1-α)^-1-1。     

1-甲基-3,4,5-三硝基吡唑的结晶热力学

利用重力法测定了1-甲基-3,4,5-三硝基吡唑(MTNP)在不同溶剂中的溶解度,采用Apelblat方程和vant′t Hoff方程拟合了溶解度数据,估算了MTNP的标准溶解焓、标准溶解熵、标准吉布斯自由能、固-液表面张力和表面熵因子。通过对比溶解度,选用苯、甲醇和无水乙醇作为溶剂分别对MTNP结晶并且进行产品表征。结果表明,MTNP的溶解度随温度的升高而增加;Apelblat方程和vant′t HoffF方程计算的溶解度值与实验值的平均绝对百分比偏差均小于5.18%,其中Apelblat方程对实验数据的关联结果较优;用电子显微镜观察无水乙醇作溶剂结晶得到的产品形貌规则且统一,其撞击感度为68%,激光粒度仪测试产品粒度均匀性较好。     

硝基胍晶体各向异性热膨胀（英）

利用原位粉末X射线衍射法和原位红外光谱法研究了硝基胍(NQ)晶体的热膨胀。结果表明, 在30~160 ℃内硝基胍a-、b-、c-轴的平均膨胀系数分别12.9×10^-6,-10.1×10^-6 ℃^-1和145.5×10^-6 ℃^-1, 显示NQ晶体热膨胀呈明显各向异性,且b轴呈负膨胀。NQ的各向异性热膨胀由其各向异性分子间作用引起。随温度升高NQ分子间氢键减弱,分子间距离增大,减少了NQ分子沿b轴的空间位阻,从而在分子间作用力下沿b轴收缩,导致了负膨胀。该结果有助于理解炸药分子堆积对其物理性能的影响。     

球形红细菌降解对硝基酚特性及响应面优化

以对硝基酚(PNP)为目标污染物,利用球形红细菌(Rhodobacter sphaeroides)H菌株研究其对PNP的降解特性,通过单因素实验和响应面分析相结合的方法优化降解条件,以提高H菌株对PNP的降解能力。设置不同反应体系证明了H菌株活细胞是降解PNP主体,且在厌氧光照、厌氧黑暗、好氧光照和好氧黑暗四种条件下均能降解PNP。通过单因素实验得出显著影响因素为:PNP初始浓度、pH值和温度,响应面优化后的最优降解条件为:PNP初始浓度为81.01 mg·L~(-1)、pH值8.09和温度30.49℃,PNP降解率的预测值为92.3%,与实际值(91.1%)相差1.2%(2%),说明预测值可靠。在最优条件下,H菌株的生长和PNP浓度随时间变化关系表明,在H菌株生长的适应期96 h内,PNP浓度从81.01 mg·L~(-1)降低到20.33 mg·L~(-1),降解率为74.9%,指数生长期96～168 h,PNP被快速降解,降解率达到91.1%;同时,拟合了该条件下H菌株降解PNP的一级动力学方程。     

硝基胍发射药的微观力学性能研究

为了研究硝基胍(NQ)发射药力学性能较差的原因,采用原子力显微镜(AFM)的接触模式和轻敲模式,获得了NQ预浸润法和一次性胶化法制备的NQ发射药样品内切面的形貌、相位和摩擦力信号图片,同时对NQ预浸润法制成的发射药样品进行了力谱分析.用扫描电镜(SEM)得到了NQ预浸润法制备的NQ发射药样品的脆断面照片.通过热机械分析...     

氧化剂热分解动力学及其对NQ热稳定性的影响研究

采用TG-DSC方法研究了硝基胍(NQ)、高氯酸铵(AP)、高氯酸钾(KP)、NQ/AP和NQ/KP的热分解特性。结果表明:NQ/AP的热分解失重分2个阶段,第1阶段是NQ的热分解,第2阶段是AP的热分解;NQ/KP的热分解失重分3个阶段,第1阶段是NQ的热分解,第2阶段和第3阶段分别对应KP的热分解和其产物KCl的熔化挥发;AP对NQ的热分解几乎没有影响;KP提高了NQ的热分解峰温,活化能降低了约60 k J/mol;NQ的存在使得KP的热分解活化能降低了约110 k J/mol,使AP活化能升高了约340k J/mol。     

自催化反应速率方程的导出途径及其在含能材料热行为研究中的应用

提出了经验级数自催化反应速率方程和13个派生式的导出途径。导出了描述自催化反应速率曲线特性[αmax和(dα/dt)max]的方程和反应进度(α)随时间(t)和温度(T)变化的方程。编制了计算自催化反应动力学参数(E、A或E1、A1、E2、A2)、经验级数(m、n、p)和αmax、(dα/dt)max值的计算机程序。提出了描述六硝基六氮杂异伍兹烷(HNIW)自催化分解反应的速率方程和硝化棉(NC)(12.82%、12.97%、13.54%、13.61%、13.86%、13.88%、14.14%N)自催化分解反应的动力学参数——催化系数Kcat、速率曲线特性参数和α随t变化的方程。     

2-甲基嘧啶-4,6-二酮制FOX-7的副产物合成1,3,5,5-四硝基六氢嘧啶

对2-甲基嘧啶-4,6-二酮(MPO)制备1,1-二氨基-2,2-二硝基乙烯(FOX-7)过程中的副产物二硝基甲烷进行了回收,经氢氧化钾水溶液中和制得了性质稳定的长针状晶体二硝基甲烷钾盐(KDNM),用KDNM、甲醛、叔丁胺作原料通过Mannich缩合反应制得了1,3-二叔丁基-5,5-二硝基六氢嘧啶,通过浓硫酸与浓硝酸的混酸体系硝解1,3-二叔丁基-5,5-二硝基六氢嘧啶制得了1,3,5,5-四硝基六氢嘧啶(DNNC),总产率达到78.9%(以二硝基甲烷钾盐计)。采用1H NMR、红外、质谱对DNNC和中间物的结构进行了表征。研究了p H值、溶剂、温度对Mannich缩合反应的影响以及硝化体系的选择对硝解反应的影响。确立了Mannich缩合反应的最佳工艺条件为:二硝基甲烷钾盐∶甲醛∶叔丁胺的摩尔比为1.0∶3.5∶2.0;10%甲醇水溶液为溶剂,室温下用盐酸调节p H值至8,随后升温至50℃,反应3 h,产率达到85.3%。硝解反应中采用20 m L 98%H_2SO_4与10 m L HNO_3的混酸体系作为硝解体系,产率达到92.5%。     

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.