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1.
用深能级瞬态谱(DLTS)法,结合表面光伏(SPV)法,研究了1MeV能量和不同剂量的电子辐照下对N型液相外延(LPE)、汽相外延(VPE)GaAs层逐次引入的缺陷和400-500K温区等时退火行为.讨论了随辐照剂量逐次增大及等时退火后缺陷浓度NT的变化,以及根据L2/DNT-1作图来判别电照引入的"E"缺陷能级中对少子寿命起主要控制作用的复合中心能级.  相似文献   
2.
基于现实生活中威胁生命安全事件的增多,建立了适用于寿险研究中的个体风险推广模型,解决了个体风险在保单数量较多时风险模型应用的局限性。为了简化个体风险推广模型在实际问题中的计算过程,选取了在风险模型中有重要应用的De Pril递推近似方法。给出了个体风险推广模型的De Pril递推公式替代计算方法及误差分析结果。得到结论为总理赔金额S的De Pril递推公式一阶近似为复合Poisson过程,并给出了De Pril递推公式一阶近似时,总理赔金额的各阶原点矩表达式。最后将上述结论应用到个体风险推广模型破产概率的研究中,针对该模型在理赔分布服从指数分布情况下,进行了数值分析与图形描述,从而能更直观的观察出各参数对破产概率的影响。  相似文献   
3.
在本工作中,首次用近红外光致发光法观察到在GaAs衬底上用金属有机化学相沉积方法(MOCVD)生长的Ga_(0.5)In_(0.5)P外延薄膜所发射的1.17、0.99及0.85eV的个新发光峰。其中只有1.17eV发射与Ga_(0.5)In_(0.5)P外延薄膜的部分有序结构有关。实验获得的1.17eV发射的变温与变激发强度特性可用受主-施主对复合来很好地给予解释。该受主-施主对系由镓空位作为受主及与其最邻近的镓子格子上的碳作为施主所组成。在考察Ga_(0.5)In_(0.5)P外延薄膜的部分有序结构与其受主-施主对复合能间关系的基础上,导出了受主-施主对跃迁的新的能量方程。  相似文献   
4.
Recent work has led to significant advances in our understanding of the late steps of genetic recombination and the post-replicational repair of DNA. The RuvA and RuvB proteins have been shown to interact with recombination intermediates and catalyse the branch migration of Holliday junctions. Although both proteins are required for branch migration, each plays a defined role with RuvA acting as a specificity factor that directs RuvB (an ATPase) to the junction. The RuvB ATPase provides the motor for branch migration. The next step is catalysed by RuvC protein which recognises Holliday junctions and promotes their resolution by endonucleolytic cleavage. New data indicates an alternative pathway for Holliday junction processing. This pathway involves RecG, a branch migration protein which is functionally analogous to RuvAB, and a protein (activated by arus mutation) which works with RecG to process intermediates independently of RuvA, RuvB and RuvC.  相似文献   
5.
Generally speaking, the intron size positively correlates with recombination rate in Caenorhabditis elegans genome. Here, we analyze the correlations between recombination rate and some measures of different intron lengths so as to know whether the recombination influences the introns of different lengths in the same way. Results show that the correlation between the recombination rate and the percentage of short introns (<100 bp) is negative, but the correlation between the recombination rate and the percentage of introns that are larger than 500 bp is positive. Average intron length correlates positively with the recombination rate for introns whose length is in the range of 100–1000 bp. We speculate that the recombination mainly exerts impact on introns whose length ranges from 100–1000 bp. We also show that the average intron number per gene correlates negatively with the recombination rate.  相似文献   
6.
汉字词属性重组是中信息技术基础研究的一个重要手段。本主要介绍了基于C/S模式的汉字属性OLAP系统中的三大模块之一:一个汉字词属性重组工具的设计,中首先给出了一此相关的概念:C/S模式,汉字词属性和重组原理等;在此基础上,给出了属性重组模块所隶属系统的数据分布环境及其详细实现步骤的设计。  相似文献   
7.
研究索赔次数为复合Poisson-Geometric风险下索赔额的一种修正分布的保险混合分红问题,运用动态规划原理建立了混合分红函数满足的HJB方程,通过求解HJB方程得到了其显式解,最后用数值算例分析了偏离系数对混合分红的影响,对保险资金的管理具有一定的指导意义。  相似文献   
8.
采用pH值检测新技术和高性能pH值检测元件及单片机,研制出一种精度高、功能强、操作方便的动态pH值监测记录系统,可广泛用于电力、环保、废水处理过程中pH值的自动检测和分析处理。  相似文献   
9.
The root-feeding aphids of the tribe Tramini have been cited as a possible case of ancient apomixis, as there are no substantiated records in the literature of a functional bisexual generation, even in common and well-known European species. The karyotypic variation found in this group, involving considerable structural heterozygosity within species, also pointed to the decay of diploidy that would be an expected consequence of loss of sexuality and absence of meiosis. However, we have now found a small number of oviparae (mating females) and males in populations of the common species Trama troglodytes. Fertilized eggs were not obtained, but adult oviparae contained large, yolky eggs. The single adult male was apterous, small and blind, but had fully developed mouthparts and genitalia, and contained mature sperm. Both sexual morphs are described, and the karyotrypic variation is reassessed in the light of these findings. Occasional sexual reproduction is in concordance with recent molecular evidence that some recombination occurs in T. troglodytes and related species.  相似文献   
10.
本文研究了我校近两年选育的7个早杂新组合在我省作早稻栽培的可能性及应用价值。威优242—2比威优49早4~5d,单产与威优49相近,日产量比威优49高,稻米品质优良,中抗稻瘟病和白叶枯病,可望在我省作中熟早稻栽培。汕优242—2比威优49早3d,产量比威优49略高,且成熟时落色好;对稻瘟病的抗性明显优于威优49,稻米品质优良,可在我省作中迟熟早稻种植。  相似文献   
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