点阴极电场辅助阳极连接中的紧密接触面积和电流

用等效电路的方法研究了点阴极情况下的电场辅助阳极连接效应，计算了连接电流，连接孕育期和紧密接触面积，本文结果表明，连接初期电流迅速衰减，随后缓慢变小，直至某一稳定值，孕育期随温度上升指数下降，连接温度高时，孕育期将难以观察到；待连接表面之间紧密接触面积随时间延长而非线性扩展，紧密接触区域增大时，其边界向外推进速度渐小，而接触面积增加渐快。     

Unfolding mechanism of rubredoxin from Pyrococcus furiosus

As part of our studies on the structural and dynamic properties of hyperthermostable proteins, we have investigated the unfolding pathways of the small iron-sulfur protein rubredoxin from Pyrococcus furiosus (RdPf) at pH 2. Unfolding has been initiated by temperature jump, triggered by manual mixing of a concentrated protein solution into a thermally preequilibrated buffer. The process has been followed in real time by absorption, tryptophan fluorescence emission, and far-UV circular dichroism. Unlike the case of the mesophilic rubredoxin from Clostridium pasteurianum (RdCp), RdPf displays a complex unfolding kinetics, pointing to the formation of at least three intermediates. All of the steps, including the one involving metal ion release, are extremely slow. However, hydrophobic core relaxation--not Fe3+ loss--is rate-determining for RdPf unfolding. This clearly rules out the fact that Fe3+ is solely responsible for the kinetic stability of RdPf. Results have been discussed in terms of sequential vs parallel pathways, and the possible role of irreversible phenomena has been taken into consideration. Aggregation does not appear to play a significant role in the observed kinetic complexities. According to a proposed sequential mechanism, partial release of secondary structure elements precedes iron loss, which is then followed by further loss of beta-sheet content and, finally, by hydrophobic relaxation. Although the main features of the RdPf unfolding mechanism remain substantially unchanged over the experimentally accessible temperature range, final hydrophobic relaxation gets faster, relative to the other events, as the temperature is decreased. A qualitative assessment of the unfolding activation parameters suggests that this arises from the very low activation energies (Ea) that characterize this step.     

Behavior of chemically modified cellulose towards dyeing. XIV. Behavior of cotton and crosslinked cottons before and after mercerization towards some reactive dyestuffs

Cotton fabric was crosslinked with DMDEU by applying the Form D-Process and Form W-Process. The cotton and crosslinked cotton were then treated with caustic soda solution of mercerizing strength. The ability of cotton and crosslinked cottons to dyeing with two reactive dyes, viz. Procion Blue MRB and Procion Red HB was examined. It was found that crosslinking reduces significantly the amenability of cotton to reactive dyes particularly when the Form D-Process was applied. Mercerization enhances dyeability of all substrates, but the enhancement was much greater in the case of noncrosslinked cotton. Based on dyeing and other properties such as tensile strength, elongation at break, and crease recovery, it was shown that crosslinking decreases considerably the affinity of cotton to caustic soda solution. It was further anticipated that different color designs with different patterns and properties can be conferred on a given cotton fabric by making use of local crosslinking and/or mercerizing followed by dyeing.     

大武岩溶水源地地下水水化学特征及其影响因素

选取北方典型岩溶裂隙含水系统,利用水文地球化学方法和统计学方法分析其地下水水化学特征及其影响因素,结果表明:沿着地下水主径流路径,地下水水化学类型种类逐年增加,除水岩作用外影响水化学类型的Ca~(2+)、Cl~-、Na~+、SO_4~(2-)多来源生活污水、工业废水和生活垃圾,且地下水中挥发性有机污染物的检出及NO_3~-、VOCs时空输入的多变性,表明区内地下水水化学持续受到人类活动的影响;利用比例系数法和因子分析法等获知影响地下水水化学的主要过程为水岩相互作用、阳离子交替吸附作用及溶滤作用,综合分析水化学类型和聚类分析可解译出监测点接收的物质组分及来源、地下水水化学动态变化过程及影响因素。     

辽宁省玉米水分生产率时空变化规律及影响因素

基于 2005- 2017 年辽宁省 14 个地级市玉米种植数据、灌溉用水量及气象数据等资料, 运用线性倾向估计及全局空间自相关分析等方法, 从不同地区、不同降水年型( 枯、平、丰) 角度出发, 分析不同玉米水分生产率指标的时空变化规律及其影响因素, 结果表明: 在时间尺度上, 全省玉米灌溉水分生产率多年平均值为 11 63 kg / m3 , 玉米水分生产率总体每 10 a 以 01 04 kg/ m3 的速率波动上升; 在空间尺度上, 全省玉米灌溉水分生产率均值呈现出西北 高、东南低的空间分异, 玉米水分生产率在枯水年( 2006) 和平水年( 2007) 总体均表现为东北高、西南低, 而丰水年 ( 2012) 则表现为西北高、东南低; 玉米单产量是影响各水分生产率指标最显著的因素。该研究成果可为提高辽宁省农业用水效率、缓解水资源压力提供一定参考。     

基于图着色理论的最大效用频谱分配算法

研究基于图着色理论的频谱分配算法,提出一种改进的最大效用频谱分配算法。该算法生成类似于ISAA算法的用户效用矩阵和相应的干扰矩阵,选择最大效用用户或干扰值为0的用户进行频谱分配。仿真结果表明,该算法能有效减少频谱分配的时间开销,提高频谱的使用效率,最大化认知无线电系统的总效用。     

斜拉桥索导管的施工监控

斜拉索是斜拉桥的重要组成部分。是弹性连续主梁的弹性支座。其到位精度直接影响主梁的受力。所以它的施工监控就十分重要。结合仙桃汉江公路大桥索导管的施工监控过程，对索导管的场内加工、安装就位、成品验收等一系列监控流程作了详细介绍，并提出一些积极建议，以期对斜拉桥的施工起到推进作用。