数字电视用中分辨率74cm纯平彩色显像管BC配列不良的分析与对策

通过对74cm中分辨率纯平彩色显像管BC配列局部严重群散不良的调查分析,确定荫罩受力塌陷是主要原因,通过改良设计、工艺优化及其它方面的综合对策,使以上技术难题得到满意的解决,整管不良率由4.78%下降到0.172%。     

Damage Development in Gray Cast Iron under Static Deformation

The authors discuss the results of experimental investigation of structural degradation of gray cast iron at various stages of static tensile deformation. Analysis of the deformation process has revealed that damageability of a material under loading can be assessed by both a special strain parameter and scatter of hardness characteristics or a ratio of the modulus deviation to the current value of the elastic modulus. A correlation between these parameters has been established.     

生长条件对KDP晶体中散射颗粒的影响

利用透射电子显微技术对不同条件下生长的KDP晶体中包裹物进行了观察并测量了其相应尺寸。结果表明，晶体中的生长缺陷、pH值、生长速度和杂质与KDP晶体散射颗粒的形态存在密切关系。     

Investigation of the Correlation between Texture and Microstructure on a Submicrometer Scale in the TEM

In recent years the investigation of local texture and microstructure by analysis of electron backscatter diffraction patterns (EBSP) in the SEM has become a very powerful and popular method. With the introduction of SEM with field emission guns (FEG) the spatial resolution of EBSP measurements could be enhanced from 500 nm with a tungsten emitter to better than 50 nm. This evolution of SEM techniques raises the question whether transmission electron microscopy (TEM) still has fields of application in texture research. The present article answers this question with a clear “yes” and presents three examples of investigations where TEM is indispensable. The three examples comprise the investigation of the correlation between dislocation structure and deformation texture, a study on nucleation mechanisms of recrystallization in highly deformed metals and the investigation of microtexture and microstructure in nanocrystalline materials. Together with the presentation of these cases some of the necessary measurement techniques are described briefly. It is shown that TEM has to be applied when highest spatial resolution of orientation determination and imaging and high accuracy of orientation determination are to be reached, when the three‐dimensional and quantitative characterization of lattice defects is required or when materials with a high density of lattice defects are to be investigated.     

Generalized null space uncorrelated Fisher discriminant analysis for linear dimensionality reduction

We propose a generalized null space uncorrelated Fisher discriminant analysis (GNUFDA) technique integrating the uncorrelated discriminant analysis and weighted pairwise Fisher criterion. The GNUFDA can effectively deal with the small sample-size problem and perform satisfactorily when the dimensionality of the null space decreases with increase in the number of training samples per class and/or classes, C. The proposed GNUFDA can extract at most C-1 optimal uncorrelated discriminative vectors without being influenced by the null-space dimensionality.     

散射式浊度测量仪

浊度是一项评定水质的重要技术指标。如何提高测量浊度的精度是国内外一直在研究的问题之一。文章介绍了作者在散射式浊度测量仪设计过程中，为提高浊度的测量精度和稳定性所做的工作。在测量仪的部件（光学系统，电路系统等）设计中，采取了许多特殊方法，使浊度测量的各项精度指标都得到了较大的提高。     

基于散射通信的雷达情报传输系统方案设计

针对传统雷达情报传输方式灵活性、机动性差或受地理环境和通信距离限制较大的现状,在分析散射通信的原理和特点以及散射传输可行性的基础上,提出一种基于散射通信的雷达情报传输系统方案设计.该方案采用具有较好抗干扰能力的扩频通信技术,通过对流层散射传输信息,系统能够在复杂地形或特殊场合的雷达站和旅团情报中心之间实现超视距无线传输.仿真结果表明系统的误码率小于10 3.该设计在战时可作为一种重要的雷达情报应急传输方式和备份手段.     

异步脑—机接口的空闲状态检测新方法*

提出一种新的空闲状态检测方法,以训练集中各类运动想象样本的类内散度和正确检测率为指标,结合接收机曲线确定分类阈值,设计最佳三分类器,并采用模糊化技术对预测标签进行处理。将该方法应用于2005年BCI竞赛数据IVc,测试的均方误差为0.278 7。实验结果验证了该方法的有效性。     

Incoherent scatter spectra due to HF heating in the low ionosphere region

The electron velocity distribution function and the incoherent scatter spectra during ionospheric heating in low ionosphere region are presented with consideration of the elastic collision between electrons and neural particles and the excitation of rotation energy level. The effects of pump frequency and electric fields on the spectra are discussed. With the increase of electric field, the non-Maxwellian feature is enhanced, and with the increase of heating frequency, the non-Maxwellian feature is weakened. The non-Maxwellian factor will bring a large error in ionosphere parameters, which must be considered in the inversion. Supported by the National Natural Science Foundation of China (Grant No. 40310223), the National Key Laboratory of Electromagnetic Environment (LEME), and National Key Technologies R&D Program of China (Grant No. 2006BAB18B06)     

基于UTD的机体散射体对机载天线耦合布局影响研究

通过研究不同形状机体散射体对机载天线间互耦特性的影响,可对飞机机载天线布局设计提供理论指导。利用一致性几何绕射理论(the uniform geometrical theory of diffraction,UTD)场的局部性原理计算典型结构问题快速、简便的优点,对半圆柱、三角柱、长方体等典型的机体散射体两侧天线耦合度进行了计算和分析验证,得到了不同形状机体散射体两侧天线的最大和最小耦合度值的粗略位置,同时也证明了该方法的正确性。最后,将上述得到的不同形状机体散射体两侧天线的布局结果应用于实际飞机的简化模型上,并通过Feko仿真了飞机机翼上两对点之间单极子天线的耦合度值,与UTD计算结果进行对比,误差较小,证实了该方法的正确性。该方法对于飞机天线布局预设计相对于普通方法具有计算简便、快速的特点,具有一定的实用价值。