Ti-15-3合金高温变形机制分析

对Ti-15-3合金进行了等温压缩物理模拟试验,计算不同变形条件下的激活能数值,探讨此合金高温变形的主要机制。结果表明,在实验范围内,变形是一个热激活过程,其中变形速率对激活能的影响不大,而随温度和变形量的升高,激活能呈下降趋势。变形合金的透射电镜照片表明位错的攀移和交滑移为合金变形的主要机制。     

High resolution linkage disequilibrium and haplotype maps for the genes in the centromeric region of chromosome 15 in Tibetans and comparisons with Han population

WITH THE SUCCESSFUL COMPLETION OF THE HUMAN GE- NOME PROJECT, ONE OF THE SCIENTIFIC MILESTONES, GENETIC VARIATIONS AND THEIR FUNCTIONAL IMPLICATIONS, HAVE BE- COME ONE OF THE FOCUSES IN GENOME RESEARCH. IT HAS BEEN KNOWN THAT GENETIC VARIATIONS, TOGETHER WITH ENVI- RONMENT, ARE RESPONSIBLE FOR THE DIFFERENCES IN COMPLEX TRAITS IN INDIVIDUALS: PHYSICAL CHARACTERISTICS, DISE…     

Analysis of proteins that interact with nucleocapsid protein of SARS-CoV using 1 5-mer phage-displayed library

Analysis of proteins that interact with N protein of SARS-CoV using 15-mer phage-displayed library will help to explore the virus pathogenesis and to develop new drugs and vaccines against SARS. In this study, we cloned, expressed and purified N protein of SARS-CoV. This 46-kD N protein was verified by SDS-PAGE and Western-blot. Then, the peptides binding-specific to N protein were identified using 15-mer phage-displayed library. Surprisingly, all of the 89 clones from monoclonal ELISA were positive （S/N〉2.1） and the result was further confirmed experimentally once again. Six N protein-binding peptides, designated separately as SNA1, SNA2, SNA4, SNA5, SNA9 and SNG11, were selected for sequencing. Sequence analysis suggested that SNA5 shared approximatively 100% sequence identity to SNA4, SNA2, SNA9 and SNA1. In addition, the binding specificity of the 15-mer peptides with the SARS-CoV N protein was further demonstrated by blocking ELISA using the synthetical 15-mer peptide according to the deduced amino acid sequence of SNA5. Also, the deduced amino sequence of SNA5 was compared with proteins in translated database using the tblastx program, and the results showed that the proteins with the highest homology were Ubiquinol-cytochrome c reductase iron-sulfur subunits （UCRI or UQCR）, otherwise known as the Rieske iron-sulfur proteins （RISP）. Notablely, in the [2Fe-2S] redox centre of UCRI, there were 6 residues [GGW（Y）F（Y）CP] compatible to the residues （position 2→7, GGWFCP7） of the NH2-terminal of the 15-mer peptide, which indicated higher binding specificity between the N protein of SARS-CoV and the redox centre of UCRI to some extent. Here, the possible molecular mechanisms of SARS-CoV N protein in the pathogenesis of SARS are discussed.     

基于主成分分析的测光红移方法

通过对最新的合成星系光谱库GALAEV进行主成分分析（principle component analysis，PCA），发现该光谱库所包含的信息可以充分压缩为3个本征谱，用其可精确地重构真实星系的谱能量分布．结果显示，用PCA得到的3个本征谱可作为模板估计星系的测光红移．我们使用BATC15色测光系统，用合成与真实星系测试了用这一套模板决定的测光红移精度，结果显示对于测光误差约为σm=0．05mag时，测光红移测量误差大约为σz=0．013，错误率约为0．12％；当红移低于z=1．20时，测量的误差为σz=0．012，而错误率为0．与传统方法相比，基于PCA的测光红移方法需要的模板谱数量少、运算速度快、测量的准确度较高．利用该方法可以通过对各种测光系统及其组合进行测试，选用尽可能少的中带滤光片，结合宽带测光，在保证科学目标要求的测光红移精度前提下，可最大限度地减少望远镜的观测时间．     

Secondary biogenic coalbed gas in some coal fields of China

The secondary biogenic coalbed gas, a new genetic and energy source type of coalbed gas in China, has been found in Xinji, Liyazhuang and Enhong areas. The essential characteristics of this type of gas are: (i) the major component of the gas is methane, with C1/C1-5 value higher than 0.99, indicating that the gas is part of dry gas; (ii) theδ13C1 value is in the range of -61.7‰to -47.9‰, mostly lower than -55‰, which is much lower than the estimatedδ13C1 value of thermogenic methane according to the thermal evolution degree of the coal rocks (with R0 value from 0.87% to 1.43%), showing the characteristics of the secondary biogenic gas; (iii) theδ5D value of methane ranges from -244‰to -196‰; (iv)δ13C 2 value ranges from -26.7‰to -15.9‰andδ13C 3 value ranges from -10.8‰to -25.3‰, indicating that the heavier hydrocarbons have a thermogenic origin; (v) the content of CO2 is very low, andδ13CCO2 value changes greatly, reflecting a characteristic of secondary change; (vi)δ15N2 value ranges mainly from -1‰to +1‰, indicating N2 derived significantly from air. The negative linear correlation between the contents of N2 and CH4 reflects the activity of bacteria bearing surface water infiltrating into coal beds. The comprehensive tracing indices show that the coalbed gas in the studied areas is the mixed gas of primarily secondary biogenic gas and a part of remnant thermogenic gas. The uplift of coal beds and the development of faults in the studied areas create favorable conditions for the formation of the secondary biogenic gas.     

苯基氮杂-15-冠-5-八钼多酸钠超分子配合物的结构与热分解

本文对新型超分子配合物［Ｎａ（ＮＰｈ）１５Ｃ５（Ｅｔ２Ｏ）］２Ｎａ２Ｍｏ８Ｏ２６进行了Ｘ射线四园衍射测定,该晶体属单斜晶系,空间群为Ｐ２１／ｃ,ａ＝１７８０３（４）,ｂ＝１３６７４（３）,ｃ＝１４６１０（３）,β＝１１２３３（２）°,Ｖ＝３２９０（１）ｎｍ３,Ｍｒ＝２０２１３,Ｄｃ＝２１４ｇ／ｃｍ３,μ＝１７１ｍｍ－１,Ｆ（０００）＝２０７９６３,Ｒ＝００２５６和Ｒｗ＝００２９５,并联系差热热重分析和１ＨＮＭＲ实验,讨论了配合物的热分解过程．     

残留碳化物对GCr15钢接触疲劳寿命的影响

本文综述了残留碳化物对轴承钢疲劳寿命的影响;并介绍了GCr15钢碳化物细化的工艺方法.     

稀土硝酸盐与取代苯并-15-冠-5固态配合物的合成与性质

以无水乙腈为溶剂,合成了3’,4’-二硝基苯并-15-冠-5与Ln(NO_3)_3·6H_2O(Ln=La,Ce,Pr,Nd)的固态配合物,进行了元素分析、差热、热重分析及摩尔电导的测定,初步确定了配合物的组成,证明其均是1:1型、非溶剂化、含有结晶水的非电解质。讨论了取代基对苯并-15-冠-5的配合物的影响。