Local dynamics and stability of apocytochrome b562 examined by hydrogen exchange

Cytochrome b562 is a heme-binding protein consisting of four helices folded into a classic helix bundle motif. Though retaining much of the topology of the holoprotein, apocytochrome b562 displays physical features commonly associated with so-called protein molten globules. Here, the stability and dynamics of this "structured" molten globule are probed by examination of the dependence of its hydrogen exchange behavior upon the presence of a chemical denaturant. Compared to other systems studied in this manner, apocytochrome b562 displays a limited dynamic range of hydrogen exchange rates and the analysis required the development of a quantitative approach. The protein is found to have three regions of subglobal cooperative stability. The most stable region, or core, is composed of the central two helices of the bundle, with the N- and C-terminal helices being of independent and lower stability. The dependence of the global unfolding free energy upon denaturant concentration indicates the applicability of a binding model and explains the observed difference between global unfolding free energies obtained by the linear extrapolation method and those obtained by calorimetry and hydrogen exchange. These observations place a significant restraint upon the type of folding pathway that is operative for this protein and suggest that that the N- and C-terminal helices fold and unfold independently of the core of the molecule.     

RSView32和MATLAB之间的通讯

MATLAB是一种具有强大的矩阵处理功能和绘图功能的应用软件。在许多复杂工程应用中，需要将MATLAB和其他软件交互协同工作。本文介绍了MATLAB与罗克韦尔公司的RSView32的特点，并重点论述了他们之间的通讯方法。     

滑坡灾害风险分析研究

本文对滑坡灾害的风险分析理论进行了探讨 ,阐述了影响斜坡稳定性的不确定性因素及风险 ,对国内外的滑坡灾害风险研究作了评述 ,分析了滑坡灾害的可接受风险水平。把滑坡灾害的风险评价确定为一个动态过程 ,分别从危险性评价、社会经济易损性评价、破坏损失评价和防治工程评价等方面进行综合性的评价 ,由此建立滑坡灾害的风险评价体系。     

最佳差分算子在P-SV波正演模拟中的应用

本文提出用最佳差分技术模拟在二维非均匀介质中传播的Ｐ－ＳＶ波。只要这种方法的差分算子半长度取成４－６，每最短波长取３个空间网格点就可得到精度很高的弹性波正演模拟结果。用最佳差分算子模拟Ｐ－ＳＶ波的计算速度比用传统差分格式至少快一个数量级，比目前公认的速度较快的伪谱法还要快３－５倍。     

地下室大体积砼施工及防水措施

在泉州市中山公园人防工程主体施工中 ,为保证大体积混凝土不产生冷缝与开裂 ,应注意结合现场实际进行板带的计算划分 ,并在施工防水中加强各个节点及构造的处理 ,从而杜绝渗漏现象     

Quo vadis efficiency analysis of water distribution? A comparative literature review

Recognizing the growing importance of scientific benchmarking in water distribution, we provide a comprehensive survey of the available literature. We begin with a discussion about the (limited) use of benchmarking in the regulation of UK water utilities, and then extend the analysis to regulated water sectors in other countries. We find no clear impact of public or private ownership; instead, the institutional settings appear to be a dominant driver of efficiency. Quality and structural variables are significant parameters; and water losses and population density are also important drivers. Analysis reveals that economies of scale only exist in fragmented water industries, whereas economies of density are omnipresent. We find evidence suggesting important economies of scope (e.g. between water and sewerage). Finally, we summarize the tensions that exist in attempting to measure efficiency in the water industry and draw conclusions about how to improve efficiency analysis in the future.     

GT147二苯醚系列快干无溶剂漆的研制与应用

论述以二苯醚为主的快干无溶剂漆的研制过程 ,并与T114 7无溶剂漆的性能及应用工艺进行了比较