为了合理评定双铅-2推进剂热值的不确定度,确定影响双铅-2推进剂热值不确定度的主要因素,本研究在GUM评定不确定度法基础上,精准称定实验样品,保证了重复性测量条件;讨论了实验次数对重复性不确定度的影响;阐明了温差的系统性不确定度可忽略的原因;讨论了各输入量不确定度之间相关系数应如何取值.量热体系热容量标定结果(E)=10 221.8 J/℃,其不确定度u(E)=10.574 J/℃,相对合成不确定度ur((E))=0.103％.双铅-2热值测试结果(Q)s=11 032.6 J/g,其不确定度u((Q))s=16.22 J/g,相对合成不确定度ur(Q)s=0.147％.评定方法和结果对硼粉热值不确定度评定奠定了方法和数据基础,对其他燃料热值不确定度评定具有参考意义.

为了实现单次发动机试验测得多个压强条件下推进剂的燃速,提出了一种固体推进剂动态燃速测试方法——质量流率法.该法以质量流率计算公式为依据,通过处理推进剂燃烧过程中随时间递增的压强曲线,计算得到发动机工作全过程中不同时刻对应压强下的燃速值;对比了通过质量流率法与冲量法处理得到的双铅-2(SQ-2)推进剂燃速结果;分析了特征速度和喷管喉径变化对质量流率法燃速测试结果的影响.结果表明,两种方法得到的燃速结果随压强变化趋势完全一致;当压强为9.945 MPa时,两种方法的误差为1.06％;当压强为22 MPa时,误差为3.87％.造成质量流率法与冲量法燃速结果之间差异的主要原因为喷管喉径实际尺寸的变化.

为了解决固体推进剂在高压下燃速测试方法的不足,提出了一种固体推进剂高压动态燃速测试方法——冲量燃速测试法.该方法通过固体推进剂在火箭发动机中的增面燃烧,得到发动机工作过程中的递增F—t曲线和p—t曲线,根据单位时间产生的冲量与已燃烧推进剂质量的关系(冲量法),计算得到了发动机工作全过程中不同时刻对应压强下的燃速值.实验对比了在助推器中常规双铅-2(SQ-2)推进剂的燃速与冲量法测得的燃速,并通过测试某中能推进剂的燃速对冲量燃速测试法进行验证.结果 表明,冲量法测得SQ-2推进剂在压强为10.62、7.89和7.63 MPa下的燃速分别为12.134、11.369和11.258mm/s;而助推器法在相应压强下的燃速分别为12.056、11.104和10.91 mm/s,冲量法所得结果略高,最大误差约为3％;冲量法测得某中能复合推进剂的燃速特性为r=6.46p0.443 (p=8～23 MPa)、r=3.49p0.635 (p=23～47 MPa);实现了通过单次增压实验测试固体推进剂任意压强点的燃速.

采用2,4和10μm镍箔作为中间层,在1 120℃/4 MPa/60 min焊接条件下,对高温合金GH4099进行固相扩散焊.采用SEM,EDS分析接头形貌演变、元素迁移,并利用拉伸试验测试其力学性能.结果表明,添加镍中间层能促进界面的孔洞闭合.随着镍层厚度由10μm降低至2 μm,界面处出现晶粒共生现象,元素扩散更加均匀,焊缝析出较大尺寸的强化相,接头抗拉强度提高,2 μm中间层接头平均抗拉强度达到1 180MPa.但随着中间层减薄,接头性能对表面粗糙度敏感,拉伸过程中母材对中间层拘束作用使接头塑性变形受到抑制,断后伸长率反而降低.

为解决摩擦焊中的产热问题,引入了摩擦阻抗的概念,并将其中的摩擦阻抗划分为滑动摩擦阻抗和粘着摩擦阻抗.结合旋转摩擦焊、搅拌摩擦焊相关研究,从塑性环(或塑化区)的萌生、生长,以及搅拌摩擦焊的周期性现象切入,给出了两种摩擦焊过程中不同的摩擦阻抗演变机制,努力回答了摩擦产热与变形产热作用时空及贡献大小等长时间困扰学术界的问题.

The field emission properties of carbon nanotubes are excellent, therefore they are a promising source of electron emission. The emission mechanism of nano-materials are explored in this paper, the electromagnetic software CST is used for building simulation models, and appropriate simulation environment is developed according to the specific structural characteristics of the carbon nanotubes. The simulation results are of great importance to the study of using carbon nanotube array as field emission cathode microwave tube.

复杂目标的激光雷达散射截面（LRCS）一直以来是激光探测和隐身中很重要的一个参数。对于LRCS计算的理论方法已经比较成熟,但是在将目标建模、目标表面材料涂覆、且标整体LRCS计算相结合的一体化设计方面,还存在一些有待解决的问题。针对该问题,介绍了一种基于Unigraphics造型软件,结合图形电磁计算（GRECO）以及双向反射分布函数（BRDF）模型的复杂目标（涂覆）LRCS计算软件的一体化开发方法。计算实例表明,使用这种方法,程序的一体化设计效果良好,而且具有较高的计算精度和准确性。

The close space sublimation method was used for the epitaxial growth of thick CdZnTe single crystal films for high-energy radiation detectors.High quality CdZnTe epilayers had been successfully grown on a GaAs(100)substrate by CSS method.Crystalline quality of the upper and lower surfaces of the epilayer was as-sessed from X-ray rocking curve measurements and photoluminescence(PL)spectra after GaAs(100)substrate had been removed by Chemical etching.The density of defects in the epilayer decreases with increasing the thickness,which suggests that the high-quality epilayer can be obtained by increasing the thickness.No Te in-clusions in the CdZnTe films grown on GaAs(100)were observed with IR transmission imaging.The film resis-tivity was in the order of 1010 Ω·cm,which shows a good photoelectric property.

基于缺陷化学理论,考虑到富Te的CdTe晶体中可能存在的点缺陷,建立了在Te气氛下退火时,热力学平衡态晶体中的点缺陷模型,其中包括Cd间隙(Cdi)、Cd空位(VCd)、Te间隙(Tei)和Te反位(TeCd).利用质量作用定律和伪化学平衡方程计算了富Te情况下本征CdTe晶体中的点缺陷浓度和费米能级.计算结果系统的揭示了点缺陷浓度、费米能级、Te压以及退火温度之间的关系,发现只有TeCd浓度足够大时才能对费米能级产生钉扎作用.

随着无线通信传感器以及微机系统等技术的日益成熟,传感器信息获取技术也逐渐向集成化、微型化和网络化的方向发展,无线传感器网络因此孕育而生.这种通过大量的微型传感器节点进行无线电通信形成的自组织网络系统,能够协作地采集、处理和传输网络区域中的信息,成为了连接物理世界、数字世界和社会的桥梁,在军事和民用上有广泛的应用.因此,如何设计有效且安全的路由协议来降低网络能量消耗、延长传感器节点和整个网络的生存周期成为研究无线传感网的焦点问题.

Conventional engine pressure acquisition method is a analog circuit,based on current-ratio-meter.It has low precision and brings ineluctable temperature excursion.According to the shortcoming,a intelligent acquisition system based on digital signal processor(DSP) was designed.Samples of temperature excursion voltage of pressure sensor are collected,and a temperature excursion regression curve equation based on the samples could be found out.The paper designed the software of pressure testing arithmetic according to the equation.When sensor works in different temperature,software will automatically compensate its excursion voltage.The result proves it has high acquisition precision than the conventional analog circuit.

Support vector machine(SVM),which is based on structural risk minimization principle,is now widely used in pattern recognition,function approximation and other research fields.It shows better generalization ability than traditional statistical learning theory,especially,when used to small sample.Some dimensionless parameter is selected as the eigenvalue,and support vector machine is applied to fault diagnosis in engine parameter acquisition unit.Experimental result proves that it has good capability in fault pattern classification of engine parameter acquisition unit.

A new method for performance evaluation and prediction of diesel locomotive turbocharging system has been proposed in this paper.The choice and measurement of some relative parameters are introduced.The performance evaluation of turbocharging system is completed by using fuzzy theory and the performance prediction is performed by using gray neural network.It is proved that the method can provide the theoretical foundation for using condition based maintenance for turbocharger.

A new method for performance evaluation and forecast of a diesel locomotive combustion system has been proposed.The condition of combustion system are in relation to the diesel power,fuel consumption,fuel pressure,turbocharging pressure and temperature of outlet.The measuring and calculation of the parameters are introduced.The performance evaluation of combustion system is obtained by using fuzzy theory.The performance forecast is obtained by using gray neural network.The achievement is applied to the system of data acquisition and fault diagnosis in diesel locomotive.It is proved by examples that the method is viable and effective.Compared with other diagnosis methods of locomotive,the method can evaluate and predict the conditon of combustion system comprehensively.The method provide the reliable basis for the maintenance of diesel locomotive.

A new method for fault diagnosis of diesel locomotive combustion system has been proposed.The conditions of combustion system are in relation to the diesel power,fuel consumption rate,fuel pressure,turbocharging pressure and exhaust temperature.The measuring and calculation of the parameters are introduced.The fault diagnosis results of combustion system are obtained by using momentum backpropagation(MOBP) and variable learning rate back-propagation(VLBP).The method is proved to be effective by examples.