复合掺杂对高磁导率锰锌铁氧体磁性能的影响

用复合掺杂的方法制备了高性能的高磁导率MnZn铁氧体材料。研究了Nb2O5-P2O5复合掺杂对MnZn铁氧体微观结构及磁性能的影响。结果表明,适量的Nb2O5-P2O5复合掺杂有利于促进晶粒均匀致密,提高材料的起始磁导率,降低损耗。在配方中,当ζ(Nb2O5∶P2O5)为2∶8时,起始磁导率可达到11 823。     

平板电视能效测试标准深入探讨

从指标体系的公平性、严谨性及先进性等方面比较了目前影响较大的"能源之星3.0"、EuP标准及制定中的国标草案,结果显示,国标草案中的评价指标能更好地体现"公正"、"严谨"、"先进"等这些标准制定的原则,能更好地促进产业的健康发展.     

平板电视能效测试标准解析

介绍了目前国际上主流的电视能效评价指标、能效限定值及具体的测量方法,同时提出了国内正在制定中的平板电视能效标准的主要概况和评价指标.通过比较,说明各种方法在评价使用时的区别与联系.     

DOA estimation in unknown colored noise using covariance differencing and sparse signal recovery

A direction-of-arrival （DOA） estimation algorithm is presented based on covariance differencing and sparse signal recovery, in which the desired signal is embedded in noise with unknown covariance. The key point of the algorithm is to eliminate the noise component by forming the difference of original and transformed covariance matrix, as well as cast the DOA estimation considered as a sparse signal recovery problem. Concerning accuracy and complexity of estimation, the authors take a vectorization operation on difference matrix, and further enforce sparsity by reweighted l1-norm penalty. We utilize data-validation to select the regularization parameter properly. Meanwhile, a kind of symmetric grid division and refinement strategy is introduced to make the proposed algorithm effective and also to mitigate the effects of limiting estimates to a grid of spatial locations. Compared with the covariance-differencing-based multiple signal classification （MUSIC） method, the proposed is of salient features, including increased resolution, improved robustness to colored noise, distinguishing the false peaks easily, but with no requiring of prior knowledge of the number of sources.     

Spontaneously deployable structure for space diffractive telescope

In order to satisfy the demands for diffractive telescopes in space exploration, a new deployable space diffractive telescope is designed. The structure and geometrical sizes of the spontaneously deployable telescope are preliminarily designated through the Serrurier truss principle and the optimized design theory. The finite element model of the deployable structure is established, and its deployed characteristics are analyzed. The prototype of the spontaneously deployable structure is constructed and some experiments are carried out to study its characteristics. Experimental results indicate that the deployable structure is 2.95 m in length, its repetitive deployed precision can reach less than 2 mm, the off-center error is less than 0.3 mm, and its deployed precision can be adjusted to micrometer level by actuators when it has deployed. It has simple structure, low mass, steady and reliable deployment, as well as higher precision for space diffractive telescopes.     

无人机数据链工作效能评估

针对无人机数据链工作效能评估,建立了无人机工作效能评估指标体系,根据无人机数据链的工作原理,利用Simulink搭建无人机上行遥控链路动态仿真平台,利用动态仿真平台探寻了信道译码前后误码率变化规律,对无人机上行遥控链路的可靠性效能和有效性效能进行了定量评估.     

平板显示分形扫描的伽马校正

传统的平板显示灰度扫描方法存在扫描效率不高的问题,分形扫描方法作为一种全新的平板显示扫描方法有效解决了这一问题,扫描效率达到100%,为平板显示尺寸提升和高灰度级显示提供了一种解决方法。文章设计实现了带伽马校正的分形扫描显示控制系统,该设计从平板显示特性和人眼视觉特性两方面入手讨论伽马校正过程,通过查找表的方式实现伽马校正功能,最后通过1 280×1 024分辨率平板显示器中的一个32×32像素子阵列作为显示窗口对文中提出的方法进行验证。理论和实验结果表明文中提出的校正方法可使平板显示效果更佳。     

ISO 9001与CMMI融合实施的可行性研究

论述了ISO 9001质量管理体系要求和CMMI模型的基本特点及其在软件企业中的应用现状。通过对两者的比对,深入地分析了其异同点;并进一步地研究了ISO 9001条款和CMMI各个过程域融合实施的可行性,为软件企业完善质量管理流程,提高质量管理效率提供参考。