Charge dynamic characteristics in corona-charged polytetrafluoroethylene film electrets

In this work, the charge dynamics characteristics of injection, transport and decay in porous and non-porous polytetrafluoroethylene (PTFE) film electrets were investigated by means of corona charging, isothermal and thermal stimulating surface-potential decay measurements. The results showed that the initial surface potential, whether positively or negatively charging, is much higher in non-porous PTFE than in porous PTFE. For porous film the value of initial surface potentials increases with increase of film thickness. Higher charging temperature can remarkably improve charge stability. The charge dynamics are correlated to materials microstructure according to their scanning electron micrographs.For non-porous PTFE films, polarizability change of C-F bonds is the main origin of electret charges; but for porous PTFE film a large number of bulk and interface type traps are expected because of the greater area of interface and higher crystallinity.     

不告不理与我国刑事诉讼

不告不理原则,是调整起诉和审判关系的基本诉讼原则,内涵十分丰富,有着曲折的历史发展过程。我国立法在二审审理范围、再审程序的启动等方面都没有彻底贯彻不告不理,在司法实践也存在着违背这一原则的情况,应予以改变并完善相关立法。     

均匀磁场中转动的导体上电荷的分布

指出了具有轴对称的导体在平行于轴的均匀磁场中绕轴转动时,导体内电荷呈均均分布,导体表面上出现电荷,并具体解出了导体球上的电荷分布.     

职业学校虚拟班主任制度研究

职校生由于知识基础薄弱、自主意识不强,在思想和行为方面往往有不良的表现,而简单粗暴的教育方式只会增加他们的逆反心理.因此,教师必须采用民主、平等、以人为本的现代教育理念,特别是通过人人可以担任虚拟班主任,让他们成为班级管理的主人,以主人翁的态度来对待学习和生活,从而在实践中增强自己的参与意识和集体观念,实现班级的自主化管理.     

高校学分制收费管理制度个案研究--以温州广播电视大学为例

我国多数高校已实行了教学学分制，探索和构建与之相适应的学分制收费管理制度成了重中之重。实行学分制收费后，许多学校在学生学籍管理，教务管理和日常教学管理中遇到了一些新的问题，必须建立与新的收费制度相适应的教学、教务管理体系。     

烷烃链分子电荷迁移机理的理论研究

利用密度泛函理论在B3LYP/6-311+G*基组水平上以两类饱和烷烃分子链体系为研究对象:CnH2n+1OH(n=10,12,14,16,18)和C12H25X(X=Cl,OH,NH2),讨论了烷烃链分子中末端官能团、分子链链长对分子电子结构的影响以及电荷迁移机理.计算结果表明:末端官能团对分子电子结构影响较大,分子链链长对分子电子结构影响则相对较小,而饱和烷烃链分子的电荷迁移属于空穴传输机理,而不是电子传输机理.     

总理海军事务衙门论略

清政府于1885年设立的总理海军事务衙门是洋务运动的产物。它的成立，标志着清朝军队已由单一兵种发展成为陆海军两个兵种，同时表明清朝在军事制度建设方面有了历史性突破。它的最终衰亡与晚清政府腐败的政治及僵化的体制不无关系，亦是国内外时局交相激荡的必然结果。     

NO2^-在聚合物膜中扩散系数的测定

制备由阳离子交换聚合物AQ和阴离子聚合物PVP组成的复合修饰电极,考察该电极在PH=1的0．05mol／L的H2SO4底液和含亚硝酸根的H2SO4底液中的电化学行为．计算出了NO2^-在单层膜与复合膜中的扩散系数．结果显示NO2^-在上述膜中的扩散系数基本相同.     

收费管理体制中“费改税”探讨

"费改税"和收费管理体制改革的最终目标是实现财政收入以税收为主,辅以少量收费收入的财源结构.应规范合理收费并建立健全相应管理机制,将部分具有税收性质的收费纳入税收轨道,取缔不合理收费.     

水二聚体间电荷转移与分子轨道研究

水二聚体间氢键作用受电荷转移的影响,为了研究电荷转移程度与氧氧间距离的关系,文章应用从头分子动力学方法(CPMD)并结合限定性动力学方法对水二聚体在330(±20)K时不同距离的原子电荷分布和分子轨道进行了系统计算。计算结果表明,电荷转移程度随着距离的增加而显著减弱。     

咸丰三年钦天监教案考述

传教士想利用科技达到其传教的目的,清廷对基督教传播的容忍却有限度。有清一朝发生在钦天监的教案共有三次。咸丰三年(1853)钦天监教案的发生不仅仅因为钦天监是西方传教士与清廷角逐的主要场所,还因为咸丰帝上台后内忧外患相交迭起。这次教案仅历经短短三天,并以较为温和的方式草草结案,其原因在于:无证据;钦天监不再是双方角逐的主要阵地;咸丰帝担心从严惩治会得罪西方传教士,不利于自己的统治。     

嵌岩桩非线性动力学特性

The nonlinear dynamic characteristics of a pile embedded in a rock were investigated. Suppose that both the materials of the pile and the soil around the pile obey nonlinear elastic and linear viscoelastic constitutive relations. The nonlinear partial differential equation governing the dynamic characteristics of the pile was first derived. The Galerkin method was used to simplify the equation and to obtain a nonlinear ordinary differential equation. The methods in nonlinear dynamics were employed to solve the simplified dynamical system, and the time-path curves, phase-trajectory diagrams, power spectrum, Poincare sections and bifurcation and chaos diagrams of the motion of the pile were obtained. The effects of parameters on the dynamic characteristics of the system were also considered in detail.     

一类动态特性稳健设计中的响应曲面分析

针对含多个噪声因素的动态特性的稳健设计,建立了响应曲面模型,给出了模型的统计分析方法,得出了有关统计量的统计分布及效的估计。     

非英语专业学生写作中的中动构式变化特征分析

本文以构式语法和中动构式理论为基础,通过对非英语专业一至四年级本科生的英语写作为语料,分析学习者在不同学习阶段中对何种动词、主语以及副词能用于中动构式所做的判断情况,以及该特征和汉语迁移的相关性。并基于研究结果得出关于大学英语写作教学的一点启示。     

抗震动力学课程网络教育平台探析

夯实动力学课程的理论水平与数值分析技能,是开展水工抗震领域相关研究的重要基础。然而,动力学概念与分析手段对于许多高年级本科生或硕士研究生来说,都显得过于复杂,难以在短时间内领悟,一定的怠学情绪存在于课堂教学中。本文拟从拓展教学手段的角度出发,尝试探讨网络平台教育的可行性,对该问题做一分析,在生动地拓展同学知识面的同时,激发学习热情,为实现教育教学资源的高水平立体化而服务。     

安徽高校体育专业毕业生心境状态及其动态变化的研究

对体育专业毕业生心境状态及其变化特点进行初步观测,在6个月的时间内分4次对安徽省普通高校体育专业毕业生男184名和女105名采用简明心境量表测量心境。结果表明：体育专业毕业生心境状态不容乐观;与学生常模相比,体育专业毕业生在首次测查和第2次测查中均表现出较多的紧张焦虑情绪;女性体育专业毕业生心境状态较男性差（P〈0.05）;社会体育专业学生心境状态优于其他三个体育专业毕业生。     

Computational fluid dynamics simulation of formaldehyde emission characteristics and its experimental validation in environment chamber

We investigated the effect of supply air rate and temperature on formaldehyde emission characteristics in an environment chamber. A three-dimensional computational fluid dynamics （CFD） chamber model for simulating formaldehyde emission in twelve different cases was developed for obtaining formaldehyde concentration by the area-weighted average method. Laboratory experiments were conducted in an environment chamber to validate the simulation results of twelve different cases and the formaldehyde concentration was measured by continuous sampling. The results show that there was good agreement between the model prediction and the experimental values within 4.3% difference for each case. The CFD simulation results varied in the range from 0.21 mg/m3 to 0.94 mg/m3, and the measuring results in the range from 0.17 mg/m3 to 0.87 mg/m3. The variation trend of formaldehyde concentration with supply air rate and temperature variation for CFD simulation and experiment measuring was consistent. With the existence of steady formaldehyde emission sources, formaldehyde concentration generally increased with the increase of temperature, and it decreased with the increase of air supply rate. We also provided some reasonable suggestions to reduce formaldehyde concentration and to improve indoor air quality for newly decorated rooms.     

Study on the applicability of frequency spectrum of micro-tremor and dynamic characteristics of surface ground in Asia area

INTRODUCTION It is well known that micro-tremor observation is one of the most convenient methods for investi- gating the dynamic characteristics of the surface ground and the affected structure (Bard, 1998; Dow- rick, 1997). Micro-tremor is a kind of geophysics information related to soil formation of site, corre- sponding to engineering geological condition. The frequency characteristics of micro-tremor can be obtained by spectral analyses of its signals, which can be used to probe into…