粘附和根切对模态局部化加速度计的影响

为研究基于单面刻蚀的微机电系统制造工艺对模态局部化加速度计的影响,通过分析释放和刻蚀工艺对模态局部化加速度计结构的影响以及对加速度计幅频特性和初始工作点的影响研究了粘附和根切对模态局部化加速度计的影响。结果表明：释放氧化层时由于液体张力的存在极易使得器件层与基底层发生粘附,导致器件失效;根切会导致谐振器之间的质量差异,从而导致加速度计初始幅值比较大的漂移,增加了信号检测的难度。可见基于单面刻蚀的微机电系统制造工艺会增加模态局部化加速度计传感器的不确定性。     

一种新犹豫模糊符号距离及其应用

研究了属性权重部分已知的犹豫模糊多属性决策问题.针对犹豫模糊元中为便于计算添加的多余数值影响方案排序等问题,提出一种新的犹豫模糊决策方法.首先,提出一种新的犹豫模糊元得分函数与犹豫度.基于此,构造一种新的犹豫模糊符号距离,对犹豫模糊元中添加的多余数值具有很好的鲁棒性.其次,基于max-min算子思想,建立属性权重优化模型.最后,将新的犹豫模糊符号距离应用于求解多属性决策问题中,并通过算例说明所提方法的可行性与有效性.     

数据缺失状态下目标威胁评估的AR(p)动态突变排序法

针对目标威胁评估过程中观测数据缺失、难以综合考虑来袭目标的动态威胁态势以及已有评估方法大多需要确定各指标权重而过多依赖专家经验的问题,将自回归(auto regressive,AR(p))预测模型、时间序列赋权及突变理论相结合,提出了目标威胁评估的AR(p)动态突变排序法。该方法通过AR(p)模型预测时间序列上的缺失目标数据,为综合各时刻数据进行威胁评估提供了基础数据信息;采用泊松分布逆形式对时间序列进行赋权,全面考虑了当前时刻和之前时刻的目标关联信息;在突变理论基础上抽象出了突变排序的思想,将目标威胁评估指标体系中下层指标对上层指标的作用归因为控制变量对状态变量的作用,并采用归一化公式对作用程度进行求解,以此方式由底层往上逐层推进最终得到目标威胁评估值。实例分析结果表明,AR(p)动态突变排序法适用于目标数据缺失时的威胁评估,更贴合实战,且不需确定各指标权重,计算过程简洁高效,可操作性强,由于综合考虑了目标的动态威胁态势,评估结果更加合理,具有一定的实用价值。     

草莓冻结玻璃化保存的实验研究

以草莓为样品进行了食品冻结冻玻璃化保存的实验研究,结果表明,贮藏于玻璃态（－７５℃）的草莓质量明显优于贮藏在一般商用温度（－２９℃,－１８℃）下的草莓质量。     

计算机病毒的检测与清除

本文在分析了计算机病毒的结构的基础上,重点讲述了计算机病毒的检测与清除的主要理想与方法。其中在病毒的检测中介绍了检测病毒的原理,以及如何检测内存中的病毒、引导型及文件型病毒、在病毒的清除部分介绍了清除病毒的原理、以及如何用多种方法清除病毒。     

多相物质的有效导热系数

对由固体球状颗粒和经历了相变的充填物所组成的多相充填床建立了数学模型,对充填物的熔化和凝固过程进行了数值计算,并在此基础上计算了由不同相所组成的区域内的有效导热系数．运用特殊的数学方法处理相变过程中潜热的释放或吸收,分析了导热参数的变化对有效导热系数的影响．得出有效导热系数的计算结果：对于玻璃球冰充填床,为１５６Ｗ／（ｍ·Ｋ）,和实验结果的相对误差为２５％;对玻璃球水充填床,为０７８Ｗ／（ｍ·Ｋ）,和实验结果的相对误差为３８％．这表明：用数值计算的方法研究多相物质的有效导热系数是一种行之有效的手段     

英语功能名词短语研究及其应用

根据英语名词短语的句法功能,提出了一种新的英语名词短语——功能名词短语,同时与基本名词短语和最长名词短语相比较.利用Google在线翻译系统,对存在结构歧义的句子进行了翻译,发现英汉机器翻译的错误主要是由结构歧义引起的,并应用功能名词短语的定义对结构歧义问题予以解决.实验结果表明,功能名词短语的识别能够有效消解两种结构歧义:一是与动词构成固定搭配的名词引起的歧义;二是"介词+名词"结构是作状语还是作后置定语的歧义.功能名词短语的研究对消除句法结构歧义、提高英汉机器翻译译文质量具有重要意义.     

Control of rice grain-filling and yield by a gene with a potential signature of domestication

Grain-filling, an important trait that contributes greatly to grain weight, is regulated by quantitative trait loci and is associated with crop domestication syndrome. However, the genes and underlying molecular mechanisms controlling crop grain-filling remain elusive. Here we report the isolation and functional analysis of the rice GIF1 (GRAIN INCOMPLETE FILLING 1) gene that encodes a cell-wall invertase required for carbon partitioning during early grain-filling. The cultivated GIF1 gene shows a restricted expression pattern during grain-filling compared to the wild rice allele, probably a result of accumulated mutations in the gene's regulatory sequence through domestication. Fine mapping with introgression lines revealed that the wild rice GIF1 is responsible for grain weight reduction. Ectopic expression of the cultivated GIF1 gene with the 35S or rice Waxy promoter resulted in smaller grains, whereas overexpression of GIF1 driven by its native promoter increased grain production. These findings, together with the domestication signature that we identified by comparing nucleotide diversity of the GIF1 loci between cultivated and wild rice, strongly suggest that GIF1 is a potential domestication gene and that such a domestication-selected gene can be used for further crop improvement.     

Distributed localization for anchor-free sensor networks

Geographic location of nodes is very useful in a sensor network. Previous localization algorithms assume that there exist some anchor nodes in this kind of network, and then other nodes are estimated to create their coordinates. Once there are not anchors to be deployed, those localization algorithms will be invalidated. Many papers in this field focus on anchor-based solutions. The use of anchors introduces many limitations, since anchors require external equipments such as global position system, cause additional power consumption. A novel positioning algorithm is proposed to use a virtual coordinate system based on a new concept--virtual anchor. It is executed in a distributed fashion according to the connectivity of a node and the measured distances to its neighbors. Both the adjacent member information and the ranging distance result are combined to generate the estimated position of a network, one of which is independently adopted for localization previously. At the position refinement stage the intermediate estimation of a node begins to be evaluated on its reliability for position mutation; thus the positioning optimization process of the whole network is avoided falling into a local optimal solution. Simulation results prove that the algorithm can resolve the distributed localization problem for anchor-free sensor networks, and is superior to previous methods in terms of its positioning capability under a variety of circumstances.     

精冲过程的韧性断裂

金属塑性加工时，材料内部会出现应变集中和空穴长大两种损伤，导致材料的承载能力下降与丧失．分析了精密冲裁时均匀塑性流动形成光洁表面以及空穴长大引起的断面撕裂现象，从材料细观损伤角度阐明了精冲原理，比较了精冲与普通冲裁两种不同的材料分离机制，并对精冲过程的数值模拟结果进行了讨论．