产甘油重组大肠杆菌的构建及其耐高渗透压性能的测定

克隆了酿酒酵母(Saccharomyces cerevisiae) 中的3-磷酸甘油脱氢酶和3-磷酸甘油酯酶基因,通过融合PCR构建了双基因共表达载体,将酵母细胞内应答渗透压变化的甘油合成途径引入大肠杆菌（Escherichia coli）。以葡萄糖为底物对重组大肠杆菌进行摇瓶发酵培养,该重组菌的甘油产量为1g/L。渗透压胁迫测试证明该重组菌的耐渗透压性能较出发菌株有明显提高。     

试论汉语语素的类型及其相关概念

科学研究离不开分类 ,本文通过对汉语中最基本的语法单位语素的分类研究 ,不仅准确地定义了汉语虚词 ,而且理清了汉语语法研究中长期混淆不清的两个概念———汉语虚语与附加成分的界限     

TM-Zn金属间化合物结构稳定性的第一性原理研究

基于能带结构,提出Jahn-Teller效应的诱发条件.基于声子色散曲线,揭示晶格动态稳定性和简并振动模式产生劈裂的物理特征.基于电子局域化函数和束缚能,揭示原子成键特性.结果表明,TM-Zn(TM=Ni,Pd,Pt,Cu,Ag,Au)金属间化合物发生立方到四方的相变变形过程中,结构保持稳定.     

Inferring the palaeoenvironment of ancient bacteria on the basis of resurrected proteins

Features of the physical environment surrounding an ancestral organism can be inferred by reconstructing sequences of ancient proteins made by those organisms, resurrecting these proteins in the laboratory, and measuring their properties. Here, we resurrect candidate sequences for elongation factors of the Tu family (EF-Tu) found at ancient nodes in the bacterial evolutionary tree, and measure their activities as a function of temperature. The ancient EF-Tu proteins have temperature optima of 55-65 degrees C. This value seems to be robust with respect to uncertainties in the ancestral reconstruction. This suggests that the ancient bacteria that hosted these particular genes were thermophiles, and neither hyperthermophiles nor mesophiles. This conclusion can be compared and contrasted with inferences drawn from an analysis of the lengths of branches in trees joining proteins from contemporary bacteria, the distribution of thermophily in derived bacterial lineages, the inferred G + C content of ancient ribosomal RNA, and the geological record combined with assumptions concerning molecular clocks. The study illustrates the use of experimental palaeobiochemistry and assumptions about deep phylogenetic relationships between bacteria to explore the character of ancient life.     

TS-1分子筛合成与苯羟基化反应性能考察

以TEOS、TBOT和自制的w =20 % TPAOH 水溶液为原料,合成了TS- 1 分子筛,并经IR、XRD和Raman 光谱等手段证实。用该分子筛作催化剂对芳烃羟基化催化性能进行考察,并在实验的基础上推测了TS- 1 分子筛催化芳烃直接羟基化的反应历程。     

高原鼢鼠油脂中亚油酸含量定量分析

用气象色谱方法对高原鼢鼠油脂中亚油酸含量进行了定量分析,并对方法的准确度进行了检验。结果发现:高原鼢鼠油脂中亚油酸含量为10.84%±0.38%,皂化和酯化最佳时间分别为15min和7min,亚油酸甲酯标准曲线回归系数r=0.9999,亚油酸甲酯色谱峰面积的相对偏差为0.0124,样品亚油酸甲酯回收率为95.08%。     

基于TrustZone的嵌入式系统安全性研究

嵌入式系统安全性的研究逐渐成为网络安全领域的一个重要课题。对基于TrustZone技术的嵌入式系统的安全性进行了研究,介绍了嵌入式安全操作系统、可信计算、CPU特权体系结构以及TrustZone技术。研究表明,基于可信硬件和安全操作系统的嵌入式系统安全体系,是解决嵌入式系统安全问题的可行方案。胡：2011一06—08     

基于蚁群粒子群优化算法的云计算资源调度方案

通过对蚁群算法和粒子群算法分别进行改进,利用两种算法自身优势相结合的方式建立一种蚁群粒子群算法,以提高云计算资源调度效率,解决云计算中资源调度方案优化问题.实验结果表明,该算法所消耗的时间更少,效果更好.