企业生态位理论研究现状与趋势

企业生态位理论作为组织生态学中的重要组成部分之一仍处于发展之中.目前研究主要集中在企业生态位宽度、重叠密度等角度研究生态位对企业生存与发展的影响,因此有许多尚待扩展的领域.本文主要对企业生态位理论研究主线、属性、主要流派等方面对企业生态位理论进行梳理与综合评述,并指出研究趋势.     

开关电源管耗计算及DC—DC电路分析

本介绍了电源技术领域中的后起之秀－开关电源的特点，基本工作原理及电路中功率晶体管，二极管损耗的计算方法并将开关电源与传统电源进行了比较，章还介绍了开关电源中常见的四种类型的DC－DC变换器并对其中两种进行详细分析，得出电路中各点电流电压波形，计算出电压变换比。     

"555"初始脉冲的修正

由“555”构成的多谐振荡器作为脉冲信号源时,往往会出现通电后产生的第一个脉冲比后续脉冲宽,就这种现象的原因进行具体分析,并给出其解决方法。     

控制论在犯罪人分类中的应用初探

系统科学自从创立以来就得到了自然科学界和社会科学界的广泛应用,然而在法学领域的应用却很少,本文即为系统科学在犯罪学领域深入应用的初探。文章主要阐述了《控制论》中的模糊集合在犯罪人分类要求中的应用,模糊聚类分析在犯罪人分类标准中的应用,以及时变系统理论在以矫正犯罪人为目的分类中的应用,以求有助于实际工作中对犯罪人分类的量化和系统化。     

黄化型大麦的系列研究 Ⅲ南黄大麦生长发育的调查

本文系统地报道了南黄大麦与原品种早熟3号在生育期、植株高度、叶片长宽、分蘖数以及穗部性状等方面的比较.指出南黄大麦除出土时间,倒二叶的长宽与早熟3号基本一致,剑叶长宽略大于早熟3号外,其余性状差异显著.植株矮小,生长发育缓慢,这与黄化型大麦叶色浅,叶绿体的片层结构不发达,光合机能弱,光合产物少有关.     

贾平凹的角色定位与自我身份认同

在对贾平凹的创作历程进行宏观梳理与跟踪关注的基础上,从"用笔写作的天才"、"游走在边缘的参悟者"、"非潮流化写作与'大陆文坛之独行侠'"、"意欲穷尽一切可能的'百变灵笔'"、"我是农民"等五个侧面分别勾勒出贾平凹作为作家的一些本质特征。这五个侧面在空间上的组合,使我们可以完整地把握到作家贾平凹所独有的精神气质和角色特征。     

Robust Confidence Intervals for the Bernoulli Parameter

Despite the simplicity of the Bernoulli process, developing good confidence interval procedures for its parameter—the probability of success p—is deceptively difficult. The binary data yield a discrete number of successes from a discrete number of trials, n. This discreteness results in actual coverage probabilities that oscillate with the n for fixed values of p (and with p for fixed n). Moreover, this oscillation necessitates a large sample size to guarantee a good coverage probability when p is close to 0 or 1.

It is well known that the Wilson procedure is superior to many existing procedures because it is less sensitive to p than any other procedures, therefore it is less costly. The procedures proposed in this article work as well as the Wilson procedure when 0.1 ≤p ≤ 0.9, and are even less sensitive (i.e., more robust) than the Wilson procedure when p is close to 0 or 1. Specifically, when the nominal coverage probability is 0.95, the Wilson procedure requires a sample size 1, 021 to guarantee that the coverage probabilities stay above 0.92 for any 0.001 ≤ min {p, 1 ?p} <0.01. By contrast, our procedures guarantee the same coverage probabilities but only need a sample size 177 without increasing either the expected interval width or the standard deviation of the interval width.     

Transformed Logit Confidence Intervals for Small Populations in Single Capture–Recapture Estimation

The good performance of logit confidence intervals for the odds ratio with small samples is well known. This is true unless the actual odds ratio is very large. In single capture–recapture estimation the odds ratio is equal to 1 because of the assumption of independence of the samples. Consequently, a transformation of the logit confidence intervals for the odds ratio is proposed in order to estimate the size of a closed population under single capture–recapture estimation. It is found that the transformed logit interval, after adding .5 to each observed count before computation, has actual coverage probabilities near to the nominal level even for small populations and even for capture probabilities near to 0 or 1, which is not guaranteed for the other capture–recapture confidence intervals proposed in statistical literature. Thus, given that the .5 transformed logit interval is very simple to compute and has a good performance, it is appropriate to be implemented by most users of the single capture–recapture method.     

短跑运动员的身体形态与专项素质特征

运动员选材是指通过对所选的对象进行身体形态、专项素质、生理机能、专项意识等方面的测试,把具有运动天赋的儿童、少年选拔出来的一种科学评价方法．本文仅对在短跑运动员选材中起到决定作用的身体形态与专项素质这两项指标进行分析,以探讨这两项指标在短跑运动员选材中的作用．     

解构“后爱情” ——评程青的小说《脸上露出幸福的笑容》

程青的小说《脸上露出幸福的笑容》是一幅当代爱情的经典画卷。作者以女性的视角扫描了文化女人的情感世界,以略带嘲讽的语言揭示了“后爱情”的变幻无常和情不由己。轻松的笔调既解构了当代人带有游戏色彩的爱情生活,又从本质上剖析了“后爱情”忽略女性智慧、拆除责任心的客观效果,使读者对当世的爱情故事有了形象与理性的认知。