性起源、性分化和地球早期生物的多样性

<周易>上说,"万物生于阴阳交合". 若将这里的万物理解为生活在地球上的多种多样的生物,阴阳交合理解为两性的分化及其有性生殖的过程,则这句写在三千多年前的话,用今天的科学术语可以表达成"有性生殖导致了生物的多样性".     

自适应入侵检测系统

论述入侵检测系统的基本概念,分析入侵检测系统(IDS)的关键技术及存在的问题.为了解决传统入侵检测模型所存在的问题,提出了一个自适应入侵检测系统(AIDS)模型,阐述了系统模型的结构及主要功能.运用自适应的模型生成方法,使收集数据、建立模型并将模型分配给检测器的过程高效、自动化.该模型为开放的系统模型,具有很好的可伸缩性,可大大减少使用IDS的代价,解决IDS的环境适应性问题,降低建立模型的代价,提高系统的效率.     

赋权图中最重的最长v-路与赋权周长

对2－连通非Hamilton赋权图G,本文证明：若P（u,v)是G中最重的最长路，则G的赋权周长C^w(G)≥d^w(u) d^w(v)，假设G满足文中描述的额外条件C1，C2，则max｛d^w(x),d^w(y)|d(x,y)=2｝≥m/2时，对每个顶点v,G含量最重长v-路P（u,v)使d^w(u)≥m/2，而d^w(x) d^w(y) d^w(z)≥m（当d(x,y,z)=2)时，c^w(G)≥2m/3.改进了非赋权图的周长及赋权图的赋权周长的若干已有结果。     

光学超晶格的多波长倍频实验研究

介绍了在同一块非周期结构的LiTaO3光学超晶格中，直接对皮秒掺钛蓝宝石泵浦的多波长参量激光器输出的脉冲激光倍频，实现了从可见光到红外光的倍频激光输出，其最大光－光转换效率达到90％。     

分次代数的分次Jacobson根

证明了对一般Monoid分次R－代数A（A未必有1，R是有1的交换环）的分次Jacobson根J'G（A）与作为分次环A的分Jacobson根相等，并给出了J'G（A）的几个特征。     

漫话汉字计算机输入法及其选用

介绍了各大类汉字输入法的基本情况，提出了开发与使用各种汉字输入法应注意的问题。     

Lehmer DH数与其逆之差的分布性质

设素数 p≥ 3,对模 p的任一原根 x,且 1≤ x相似文献   

核密度估计的中偏差

在一些正则性条件下，使用Gaer-Ellis定理和尾概率估计的某些技巧，得到了核密度估计在点态和一致范数下的两个中偏差定理。     

Microelement analysis of source of raw materials of terracotta warriors and horses of Qin’s Mausoleum in pits No. 1 and No. 2

In order to search for sources of the raw material of the Qin’s terracotta warriors and horses, we selected 20 samples of pottery warriors and pottery horses of the Qin’s Mausoleum from pit No. 1, 19 samples of pottery warriors and brick from pit No. 2, 20 samples of clays near the Qin’s Mausoleum and 2 samples of Yaozhou porcelain bodies. The 32 kinds of element content of each sample were measured by neutron activation analysis (NAA). These data were analyzed by fuzzy cluster analysis, the trend cluster analysis diagram was obtained. The results showed that samples of terracotta warriors and horses from pits No.1 and No. 2 were closely related to the loam layer near Qin’s Mausoleum, but their relations with the loess layers were not so close, and they were out of all relation to Yaozhou porcelain bodies. Thus, it could be deduced that the Li Mountain clay may be considered as the original place of the raw materials of the terracotta warriors and horses, the kiln sites might be located nearby the Qin’s Mausoleum.