液相外延生长高质量大功率InGaAsP/GaAs半导体激光器研究

用改进的液相外延法生长了大功率InGaAsP/GaAs半导体激光器,实验测量和理论分析都表明该方法生长的单量子阱分别限制异质结构,达到设计要求,阈值电流密度为300A／cm^2,斜率效率达1．32W／A,具有很高器件质量。     

MBE生长高功率列阵激光器的研究

利用V80型MBE生长GaAlAs/GaAs梯度折射率分别限制单量子阱(GRIN-SCH-SQW)结构.测试结果表明,该结构晶格和光学质量符合设计要求.制成激光器列阵,室温连续输出功率达7.2W,峰值波长为807～809nm,经柱透镜光纤耦合后的光强远场分布为θ∥=8°,θ⊥=3.5°.     

高功率1.55μm半导体激光器

1 .55μm半导体激光器有很多突出的优点 ,但普通的双异质结激光器功率小 ,且对温度很敏感。本文将大光腔结构形式引入 1.55μmGaInAsP/InP半导体激光器中 ,用液相外延技术研制成功了脉冲峰值功率超过 2W的 1.55μmGaInAsP/InP半导体激光器。普通双异质结构激光器特征温度T0 为 50～ 70K[1] ;而本文研制的大光腔结构为 10 0～ 140K。激光器的寿命超过 10 0 0h     

环氧树脂和石墨对高氯酸钾类烟火药撞击感度的影响

为了揭示高氯酸钾类烟火药的安全性,制备了本工作称为样品1#～7#的7种50/50/m/n-KClO4/Al/环氧树脂/石墨混合物体系(m=n=0;m=3,n=0;m=5,n=0;m=5,n=1;m=5,n=2;m=5,n=3;m=5,n=4)。用GJB772A-1997-601.1,热重-差热分析(TG-DTA)和扫描电子显微镜(SEM)研究了环氧树脂和石墨对高氯酸钾类烟火药撞击感度的影响。结果表明:样品1#～7#的撞击感度爆炸百分数分别为0,60,76,40,12,2和0。与样品1#比较,样品1#中加入环氧树脂使样品2#和3#的撞击感度爆炸百分数升高,且随样品1#中环氧树脂含量的增加,撞击感度爆炸百分数升高。与样品3#比较,样品3#中加入石墨使样品4#～7#的撞击感度爆炸百分数降低,且随样品3#中石墨含量的增加,撞击感度爆炸百分数以4#>5#>6#>7#次序降低。探讨了环氧树脂对KClO4/Al二元体系起增感作用和石墨起减感作用的原因。     

苦味酸氨基脲盐的制备与分子结构的研究

研究了苦味酸氨基脲盐的制备方法 ,并用元素分析、IR、DSC和X射线衍射对其进行了结构表征。其分子式为 :(H2 NCONHNH3 ) + [C6H2 (NO2 ) 3 O ] -。晶体属于三斜晶系 ,P墿的空间群 ,晶体学参数为 :a =5 .0 2 4(1) ,b =10 .2 0 9(1) ,c =11.5 5 1(1) ;α =79.0 0 (1)° ,β =81.11(1)° ,γ =82 .47(1)° ;V =5 71.42 (14 ) 3 ,Z =2 ,Dc=1.768g·cm-3 ,μ =0 .162mm-1,F(0 0 0 ) =3 12 ,R1=0 .0 3 2 4,Rw2 =0 .0 874     

苦味酸晶体及分子结构的研究

采用蒸发法制备苦味酸的单晶。用X射线衍射、元素分析、红外光谱对其进行了结构表征。苦味酸晶体属正交晶系 ,Pca2 (1)空间群。晶体参数为 :a =0 .92 6 84(16 )nm ,b =1.913 9(4)nm ,c =0 .9716 (2 )nm ,V =1.72 3 6 (6 )nm3,Z =4,Dc=1.76 6g·cm-3 ,μ =1.6 6cm-1,F(0 0 0 ) =92 8。最终偏离因子R =0 .0 45 4,Rw=0 .0 979。     

直三点弯曲试样K_1的MMC解

利用MMC法计算了直三点弯曲试样在S/W=3(0.5)~5、8六种情况下,a/W=0.25～0.70时的K_1B(√)~3/M值。并给出了适用于上述范围的高精度通用拟合式。     

N,N'-二[(2,2,2-三硝基乙基-N-硝基)]乙二胺的热安全性和密度泛函理论研究

借助N,N’-二[(2,2,2-三硝基乙基-N-硝基)]乙二胺的恒容标准燃烧热(Qc),不同加热速率(β)非等温DSC曲线离开基线的初始温度(To)、onest温度(Te)、最大峰顶温度,由Kissinger法和Ozawa法所得的热分解反应活化能(EK,Eo)和指前因子(AK),从方程Inβi=In[A0/be0(or p0) G(α)]+be0(or p0)Te(or p)i所得的值be0(or p0),从方程Inβi=In[A0/(ae0(or p0)+1)G(α)]+( ae0(or p0)+1) InTe(or p)i所得的ae0(or p0)值,从方程In(βi/Tei-Toi)=In(A0/G(α))+bTei所得的b值,从方程In(βi/Tei-Toi)=In(A0/G(α))+aInTei所得的a值,估算的比热容(cp)、密度(ρ)、热导率(λ)和分解热(Qd,取爆热之半)数据,Zhang-Hu-Xie-Li公式,Hu-Yang-Liang-Xie公式,基于Berthelot方程和Harcourt-Esson方程计算热爆炸临界温度的公式,Smith方程,Friedman公式,Bruckman-Guillet公式,热力学公式和Wang-Du公式,计算了由理想燃烧反应和Hess定律得到的BTNEDA的恒容标准燃烧能△cU(BTNEDA,s,298.15K)和标准生成焓△fHθm(BTNEDA,s,298.15K),β→O时的To、Te和Tp值(To0,Te0和Tp0),热爆炸临界温度(Tbe0和Tbp0),绝热至爆时间(tTlad),撞击感度50％落高(H50),热点起爆临界温度(Tcr),被350 K环境包围的半厚和半径为1 m的无限大平板、无限长圆柱和球形BTNEDA的热感度概率密度函数,相应于S(T)与T关系曲线最大值的峰温(TS(T)max),安全度(SD),临界热爆炸环境温度(Tacr)和热爆炸概率(PTE).得到了评价BTNEDA热安全性的下列结果:(1)△cU(BTNEDA,s,298.15K)=- (3478.11±6.41)kJ·mol-1和△fHθm( BTNEDA,s,298.15K)=- (53.54±6.41) kJ· mol-1;(2) To0 =438.73 K,TSADT=Te0 =440.73 K,Tp0 =446.53 K;Tbe0=449.88 K,Tbp0 =455.28 K;(3)当EK=199.5 kJ· mol-1,AK =1020.45s-1,cp=1.12 J·g-1·K-1,Qd =3226 J·g-1,T0=Te0 =440.73 K,T=Tb =455.26 K,f(α)=3(1-α)2/3,a=10-3cm,p=1.87 g·cm-3,t-t0 =10-4s,Troom =293.15 K和λ=0.00269 J·cm-1·s-1·K-1,H50=15.03 cm,tTlad=1.25 s,Tcr,hot,spot=333.86 K;对无限大平板,Ts(T)max=350K,Tacr=345.47 K,SD=28.55％,PTE=71.45％;对无限长圆柱,Ts(T)max =354.5 K,Tacr=349.73 K,SD=39.31％,PTE =60.69％;对球,Ts(T)max=357.00 K,Tacr=352.42 K,SD =45.81％,PTE=54.19％.运用密度泛函理论计算获得了BTNEDA的优化构型及红外光谱,分析了其分子总能量、前沿轨道能量和原子净电荷分布.     

{C_6H_2(NO_2)_3OK}_n的晶体和分子结构

通过 2 ,4,6 三硝基苯酚 (PA)与氢氧化钾溶液反应 ,制备了 2 ,4,6 三硝基苯酚钾 ,并用X射线衍射仪测定了其晶体结构。晶体属正交晶系 ,空间群为Ibca ,晶体学参数为 :a =0 .713 5 ( 1)nm ,b =1.333 2 ( 1)nm ,c =1.912 4( 2 )nm ,V =1.819( 3)nm3,Z =8,Dc=1.95 1g·cm-3 ,μ =13 .4m-1,F( 0 0 0 ) =10 72     

四硝基二苯并-1,3a,4,6a-四氮杂戊搭烯的晶体结构

按文献提供的方法合成四硝基二苯并 - 1 ,3 a,4,6 a-四氮杂戊搭烯 (TACOT) ,利用缓慢降温法培养了 TACOT单晶试样 ,X-射线衍射仪测定的 TACOT单晶结构表明 :TACOT属于正交晶系 ,空间群为 Pbca.晶体学参数为 :a=0 .85 81 8(2 ) nm,b=1 .1 43 3 6 (4) nm,c=1 .43 2 75 (5 ) nm;Z=4;V=1 .40 5 83 (8) nm3;dc=1 .83 4 g/mm3.本文分析了 TACOT高密度的原因。     

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.