低泵浦能量类氖锗等离子体软X射线激光实验

提出并采用具有一定时间间隔的双束脉冲加热锗薄膜靶方法，在泵浦激光能量１００Ｊ，靶长１０ｍｍ的实验条件下，观察到波长１９．６１ｎｍ和２３．６３ｎｍ两条类氖锗３ｓ－３ｐ激光跃迁线。１９．６１ｎｍ（Ｊ＝０－１）的激光跃迁线发射强度较２３．６３ｎｍ（Ｊ＝２－１）激光线的强度大，其发散角较后者小。     

Interface controlled precipitate dissolution and constitutional liquation

The paper reviews some of the kinetic aspects of second phase dissolution in binary and multicomponent systems, and relates them to the phenomenon of constitutional liquation, which is one of the causes of liquation in the subsolidus portion of the weld heat affected zone (HAZ) of these alloys. Particular attention is devoted to the concept of interface control during precipitate dissolution, and its effect on the extent and kinetics of constitutional liquation. It is shown that the presence of a sluggish interfacial reaction during precipitate dissolution has the potential to completely eliminate subsolidus liquation in the HAZ. Some of the conditions under which precipitate dissolution might become interface controlled are discussed. It is proposed that some of these variables can be controlled either through proper alloy design or through appropriate heat treatments, in order to develop microstructures which resist liquation in the subsolidus HAZ.     

A Study on the Driving Force for Binding of Benzene Derivatives by α-and β-Cyclodextrin

WehavedemonstTatedthattheassociationconstantsfortheinclusioncomplexationofa-and6-cyclodextrin(a-and9-CD)withsubstitutedbenzene(PhX)arecorrelatedwithpropertiessuchasmolarrefraction(R.),hydrophobicity(n.)andeIectroniceffect(a.)ofsubstitUentsintheguestcompounds.Uponapplicationofanariificialneuralnetwork(ANN),theassociationconstants(Ka)fortheinclusionofa-CDand6-CDwithsubstitutedbenzenewerepredictedfromR.,rrxandG.withsatisfactoryresultSl'2.Furthermore,theeffectsofsubstituentsinbenzenederivat…     

Stress-dependent molecular pathways of silica-water reaction

Stress-corrosion of silica by water is studied by exploring the stress-dependent potential energy surface computed quantum mechanically at the level of molecular orbital theory. An ordered silica nanorod with clearly defined nominal tensile stress is constructed to model a structural unit of the stressed crack tip. Three competing hydrolysis reaction pathways are determined, each involving a distinct initiation step. Water dissociation, molecular chemisorption, and direct siloxane bond rupture dominate at low, intermediate, and high stress levels, respectively. A linear stress dependence in the thermodynamic driving force, not commonly considered in the criterion of brittle fracture initiation, is shown to originate from surface relaxation associated with bond rupture. This effect is particularly important in determining the Griffith condition of crack extension for nano-sized systems when spatial accommodation of foreign molecules is involved in the process of bond breaking. The physical origin of the stress dependence of kinetic barrier is revealed by a perturbation analysis of the minimum energy path parametrized by the continuous mechanical stress.     

提高道路交通系统的驾驶安全

道路交通系统是一个复杂的系统，其中包含了人的直接参与。在该系统中，人的因素起了重要的作用。本文中，在道路系统路面的某一点设计了一种类型控制信号，该点被称为信号点。在控制信号的作用下，当车辆经过信号点的时候，车辆需要降低速度。其目的在于能够通过控制信号控制交通流的状态，使其由无序变为有序，从而提高道路系统的交通安全。应用双车道的确定性NaSch模型进行仿真模拟，结果表明不仅交通流的状态能够由无序变为有序，而且交通流的状态是安全的。     

中国省际碳排放驱动因子及趋势分析:以辽宁省为例

采用1997-2012年辽宁省碳排放时间序列数据,参照STIRPAT模型,通过因子分析和最小二乘法回归拟合得到碳排放量和5类主要影响因子的拟合方程.研究结果表明:人口、人均GDP、第二产业产值、单位GDP能耗和全社会固定资产投资每增加或降低1%将带来碳排放量增加或降低比率分别为:0.3294%、0.1544%、0.1424%、0.2675%和0.1375%.通过灰色预测模型GM(1,1)进行预测分析,预测结果为:2020年和2030年辽宁省的碳排放总量将分别达到38705.368万t和69603.215万t,碳排放强度将分别降至0.576t/万元和0.2878t/万元.     

国际天然气价格驱动因素的结构性变化

页岩气开采技术的大规模应用增加了非常规天然气供应潜力,对国际天然气市场供需格局产生了较大冲击。本文利用带结构断点的协整检验、时变系数模型和条件误差修正模型等方法系统地研究了天然气价格与原油价格的动态关系,以及库存、天气和投机等短期因素对气价变化的影响。结果显示,国际天然气价格与原油价格间的协整关系在2005年飓风季与2008年金融危机期间发生了结构性变化,而且原油价格对天然气价格的影响强度呈现倒U型结构。此外,极端天气、突发性事件及投机等短期因素对气价存在显著的短期影响。不过,随着天然气供应出现过剩局面,天然气价格对这些短期因素的敏感性已大幅降低。     

Visualization observation of cells growth in low-density polyethylene foaming processes

Low-density polyethylene (LDPE)/p, p-oxybis (benzenesulfonylhydrazide) (OBSH) system was carried out to investigate the cell growth during foaming process with a visualization apparatus at a constant temperature. The results showed that the cells growth of LDPE foams follows the Logistic function with a higher correlation coefficient of 0.96738. Here, a method was adopted to establish the relationships between cell growth and foaming process with first and second derivatives of cell mean diameter vs. time, which reflected the cells growth rate and driving force during cell growth, respectively. Moreover, we elucidated the interactions of cells growth at less-foamed, better-foamed and over-foamed stages were asymmetric during foaming process, which resulted from the greater cells deformation. This revealed the method in describing cells growth provided a visual comprehension of the mechanisms for foaming process.