The reconstruction and interpretations of lake status at 6 ka and 18 ka B.P.in inland mainland Asia

By means of survey of literature through compilations of sedimentological, biogeological and geomorphologic data, the inland lake level changes in arid or semi-arid mainland Asia at 6 and 18 ka B. P. have been reconstructed. The results showed that the lakes from western and northwestern Asia were characterized by very high water levels at 18 ka B. P., but low or intermediate water stands at 6 ka B. P. The high lake level in this region was associated with the southward displacement of westerlies, therefore, the extent of the high lake stand indicated the southern flank of westerlies during the glaciation. Conversely, the lakes from the eastern and southern Asia registered comparative low levels at 18 ka B. P. and significantly high one at 6 ka B. P. The lowering of lake level at 18 ka B. P. was caused by the weakened summer monsoon and the high lake level at 6 ka B. P. by the enhanced summer monsoon induced by the enlarged thermal contrast between land and ocean. The extent of high lake levels indicated the northern boundary of monsoon expansion. Between the above two regions, there is a climatic transitional zone in the Central Asia where the lake behavior was close to that in southeastern Asia at 6 ka B. P. but became similar to that in northwestern Asia at 18 ka B. P. Thus this zone became a transitional sector from the monsoon to the westerlies.     

开普勒第三定律表达式的一种新的推导方法

利用椭圆的几何性质由开普勒第一、第二定律推导开普勒第三定律     

悬浇梁合龙段劲性骨架结构分析

悬浇梁合龙段施工是全桥施工的关键阶段,而劲性钢骨架的埋设位置、构造形式及承载力分析又是合龙施工的关键控制内容,因此,合龙段劲性骨架在施工过程中的结构分析就显得尤为重要.以沈阳新立堡大桥为例,详细讨论了劲性钢骨架施工的理论依据及注意事项.     

在仿刺参体腔液中发现新的调理素样分子

通过研究发现,仿刺参体腔液中存在一种新的调理素样分子。通过SDS-PAGE,凝胶过滤层析,质谱分析等方法进行蛋白质的纯化和分析,采用荧光显微镜观察吞噬细胞对酵母细胞的吞噬作用,发现一种分子量约为18 kDa的分子可以结合到酵母细胞表面,并可以增强吞噬细胞的吞噬作用。推测这种分子是无脊椎动物调理素样分子中的新成员。同时也发现,虽然调理素样分子能够增强吞噬细胞的吞噬作用,但是,它不是单独起作用的,仍然必须依赖体腔液中其他未知成分,而对未知成分的鉴定需要进一步研究。     

r-排列非递归生成算法及应用

提出一种利用回溯法生成r-排列的算法.该算法使用栈和队列,并引入标记已选元素的方法,避免了回溯时的重复选择.生成的r-排列具有分组和对称性,且符合字典序.此算法也能生成全排列.利用该算法提出了r-组合生成算法,分析了它们的时间和空间复杂度,并介绍了r-排列和r-组合算法在任务安排问题中的应用.     

一种基于DTRS模型与α-正域的邮件过滤方法

提出一种基于决策粗糙集(decision-theoretic rough set,DTRS)模型的邮件过滤方法(spam filtering based on DTRS-SFDTRS).首先用α-正域约简理论对邮件数据进行属性约简,然后根据最小风险Bayes决策方法,将无法明确判断的邮件用DTRS模型的边界域进行刻画,实现正常邮件、垃圾邮件和可疑邮件的三枝决策.仿真实验表明:SFDTRS方法能显著降低数据的维度,保证邮件过滤效果的同时,提高模型训练和邮件过滤的效率.     

含FeO熔渣对ZrO2固体电解质侵蚀性研究

采用热力学计算软件FactSage中的Equilib平衡计算模块,模拟研究静态条件下SiO2-CaO-Al2O3-MgO-FeO五元渣系对ZrO2材质的侵蚀特性。利用MgO稳定的ZrO2固体电解质管与碳饱和铁液以及酸性渣构建可控氧流电池,分别进行电池在开路条件与外加电势条件下的侵蚀实验,并通过SEM、EDS分析检测,讨论酸性渣可控氧流电解时ZrSiO4新相的形成机理以及对固体电解质导电性能的影响。结果表明,ZrO2的侵蚀程度随温度的升高和渣中FeO含量的增加而增加;在低碱度和高碱度条件下,熔渣与氧化锆之间分别会有ZrSiO4和CaZrO3生成;相对于静态以及开路条件,外加电势电解条件下酸性熔渣与氧化锆之间易形成新相层,从而显著增大电池内阻,阻碍氧离子迁移,但也能减轻或阻碍熔渣对ZrO2固体电解质的渗透侵蚀;可控氧流电解时酸性渣中初始FeO含量最好低于20%,碱度R最好在0.23～0.80之间。     

某导弹模拟训练系统中虚拟环境与兵器的设计实现

通过对某导弹模拟训练系统中虚拟环境与兵器的设计实现介绍,讨论了几种Direct3D三维特效程序设计的基本途径,同时还简单介绍了作者对Direct3D API函数的可视化类库封装,该类库降低了三维程序设计的复杂度,提高了程序员工作的效率。     

High-resolution sedimentary record of hydrocarbon contaminants in a core from the major reaches of the Pearl River,China

The concentrations and compositions of hydrocarbon contaminants, and molecular marker indices in modern sediments from a core in the major reaches of the Pearl River were investigated. The sedimentary record of hydrocarbons in the core, in combination with²¹⁰Pb-dating, was used to reconstruct the pollution history of hydrocarbon pollutants in the Pearl River in the past 100 years.

     

适于RAPD分析的三种基因组DNA提取方法比较

通过对 3种基因组DNA提取方法的实验比较 ,找到了一种既能够满足RAPD实验要求 ,又简便快捷、经济的基因组DNA提取方法 ,经RAPD试验检测与电泳结果分析表明 :DNA扩增效果良好