西部开发与城市土壤侵蚀及防治对策--以黄土高原地区为例

西部大开发战略 ,必将促进西部地区经济发展和城市化进程 ,为进一步防止城市土壤侵蚀 ,分析了黄土高原地区城市化对侵蚀营力、侵蚀物源及土壤侵蚀量的影响 ;提出了转变观念、提高认识、明确指导思想和目的要求 ,做好规划 ,搞好协作 ,加强宣传与监督 ,依法防治城市土壤侵蚀等防治对策     

快速城市化条件下地下水开发的环境效应研究

赋存于寒武系和奥陶系灰岩中的岩溶水是徐州市的主要供水水源.1978年以来,随着经济的发展和快速城市化,市区岩溶地下水开采量逐年增加;而且城市西北郊煤矿的开采疏排水活动也导致大量的地下水流失.上述两种作用导致徐州市岩溶地下水位的持续下降,降落漏斗面积逐年增加,增强了地下水系统的脆弱性,诱发了诸如局部水资源枯竭、水质恶化、地下水污染和岩溶塌陷等一系列环境问题.这些环境问题具有系统性和连锁性的特征,已严重影响了城市的发展质量,增加了城市供水的风险.根据各个环境要素演化关系,本文建立了城市化条件下地下水开发的环境效应概念模型,并提出了岩溶地下水保护的措施建议.     

近代流民入城对城市化进程的影响

近代中国由于资本主义入侵、战乱、灾荒等原因，产生了大量流民。流民入城对近代城市化进程产生了一系列的影响：一方面，使近代城市人口规模迅速上升，为城市的工商业提供了充足的后备劳动力，改变了城市的社会结构，在一定程度上推动了城市化进程；另一方面，使失业人口剧增，城市市民生活质量下降，社会矛盾不断加剧，人居环境恶化，人口性别比例严重失调，人口职业结构出现畸形，城市功能受到很大影响，不利于城市的可持续发展。     

优化区域教育

城市化是指农村人口大量向城市集中，城市的数量不断增加，城市的规模不断扩大的一个历史进程。这是城市文明在社会生活中的扩张，也是社会现代化的变迁过程。城市化将进一步拓展城市的服务功能，使之成为名副其实的区域政治经济中心、信息中心、教育中心、人才中心、智力中心、文化休闲中心等。     

“绿色奥运,绿色行动”系列报道之九 透水砖:让路面环保起来

在长期城市化发展的过程中,大规模的路面硬化和新建筑造成不透水面积大大增加,使得城市雨水不能顺利地回归自然,不仅造成了地下水补充涵养大量减少,洪峰流量大大增加,加剧了城市防洪排水负担,造成城市大面积积水事件。同时,弱化了城市环境的呼吸功能(即生命功能),造成热岛效应(燥热)、扬尘和噪音加剧,恶化了城市小气候,     

城市污水处理现状及可持续发展

随着城市化进程的加快和经济建设的飞速发展，城市污水排放量也迅速增加，大量未经处理的污水任意排放，如果不能得到妥善处理，将给城市及水环境造成严重污染，影响人居环境质量和城市的可持续发展。从我国城市污水现状入手，分析了污水处理存在的问题，并提出了可持续发展的策略。     

民国时期陇海铁路入陕与宝鸡城市化建设

交通建设是城市化建设的加速器。民国时期陇海铁路西延入陕,为铁路沿线地区经济发展创造了条件,同时抗战时期的客观环境为西北城市发展提供了广袤的市场。这一时期宝鸡城市化进程步伐加快,近代工商业的发展使宝鸡城市经济功能日益凸显;城市人口数量增多,市区规模扩大成为城市化发展的显著特征;教育事业、文娱、市政建设的发展,清晰地显示出宝鸡浓厚的城市化生活气息。     

城市化进程中城市污染土地的治理研究——以美国城市棕色地块的治理为例

城市化和工业化进程的加快,造成我国城市土地污染、侵蚀、酸化、硬化和闲置等一系列较为严重的城市环境问题,制约了社会经济的可持续发展.以美国城市棕色地块(Brownfield site)的治理为例,分析了美国棕色地块的现状,棕色地块治理的社会、经济和法律措施.通过借鉴美国城市棕色地块治理的经验,为我国城市化进程所带来的土壤污染防治、土地资源再利用提供新思路、新方法。     

保护城市生态系统

城市是人类技术进步、经济发展和社会文明的标志。但它也成为了人类自然、社会、经济发展变化的矛盾焦点。城市人口的密集性给城市提供了高效的生产环境、便利的生活条件和丰富的信息来源。但随着城市化进程的加快，城市工业化发展和城市人口迅速增加，人口、资源环境之问的矛盾也越来越复杂。就在城市这块狭小的区域内进行着大量的资源、能源的利用，大量的物资交换、流通和众多的产品消费，     

环境法制在城市发展与节能减排中的作用

<正>马克思在《共产党宣言》中说,城市化使"城市人口比农村人口大大增加了起来,因而很大一部分人脱离了乡村生活的愚昧状态。"这种从封闭到开放、从贫穷到富裕、从愚昧到文明的过程是历史发展的必然。但是,随着城市化进程的加快,上世纪90年代以来,全球气候变化、环境恶化、资源紧缺已成为世界性难题,世界各国都在     

Markedness and its Interpretation in Language Use

Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.     

Features of Women's language

Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women＇s language from these perspectives： pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women＇s language, more attention should be paid to language use in social context. What＇s more, the linguistic phenomena in a speaking community can be understood more thoroughly.     

低渗透非均质砂岩油藏启动压力梯度研究

理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。     

On Tragic Consciousness In The Works By Ernest Hemingway

As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.     

Jane Eyre——A Feminist In The 19th Century

In the 19th century the society was controlled by men, and women were just appendants of them, they had not any rights and freedom. But Jane was an exception, she showed some characteristics of early feminist. Jane showed her characteristics of feminism in three aspects: rebellion, equality, and independence. These characteristics were helpful to her success, and feminism is the only way out for women of that time.     

Achieving Unusual States of Matter Under High Pressure

正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-     

Exchange-Correlation and Electronic Excitation Energies from Pairing Matrix Fluctuations

We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-     

Density Functional Theory for the Response of Periodic Systems to Electric Fields Based on the Vector Potential Approach

正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that     

On the Thermodynamic Limit for Responses to Static Electromagnetic Fields

For molecular systems,the quantum-mechanical treatment of their responses to static electromagnetic fields usually employs a scalar-potential treatment of the electric field and a vector-potential treatment of the magnetic field.Although the potential for each field separately is associated with the choice of an(unphysical)origin,the precise choice of the origin for the electrostatic field has little consequences for the results.This is different for the     

An affordable accurate evaluation of the binding conformations predicted by molecular docking studies in bio-system

Franck-Condon factors bridge the gap between theoretical modeling and experimental observations for molecular electronic spectroscopy and electron transfer.Under the displaced harmonic oscillator approximation,multidimensional Franck-Condon factors are decomposed into a product of many one-dimensional(1D)Franck-Condon(FC)factors,and each 1D-FC factor is associated with one Huang-Rhys factor that determines the leading contribution of