疏勒河流域生态环境可持续发展对策研究

分析了疏勒河流域生态环境现状及存在的主要问题，认为流域生态环境可持续发展的关键是水资源的合理利用。运用可持续发展的理论，从流域水土资源开发，生态环境的建设和管理等方面，提出流域生态环境可持续发展的对策措施。     

石羊河流域水问题及生态需水估算

水资源是西北干旱区经济发展的主要瓶颈,更是生态环境建设的关键性制约因素.本文以石羊河流域为例,从分析石羊河流域水资源开发利用现状及主要的水环境问题出发,得出石羊河流域生态环境建设必须要解决的问题是:农业结构调整、上下游之间用水矛盾的解决、大力改善水环境和加强生态建设;通过对石羊河流域水资源供需平衡与生态建设关系的分析得出该区生态环境建设必须以水资源合理利用为核心.     

石羊河流域水资源可持续利用研究

石羊河流域位于河西走廊东部 ,水资源日益短缺 ,供需矛盾突出 ,地下水严重超采 ,生态环境日益恶化 ,水资源可持续利用呈现危机。文章通过对流域内水资源利用现状分析 ,阐述引起水资源短缺的主要是由于水资源开发利用管理粗放 ,节水意识淡薄 ,节水灌溉技术推广滞后等多种因素 ,水资源浪费严重所致。提出实现水资源可持续利用的几条途径 :推广地膜种植技术、调整农业种植结构、加强水资源管理监督机制 ,进行优化配水灌溉 ,建设全流域网络化管道输水系统、推广先进节水灌溉技术 ,建立节水农业模式 ,实现全流域水资源利用的可持续发展     

石羊河流域生态环境问题突出,亟待加强治理保护

了编制《甘肃河西生态环境保护和建设规划》 ,笔者在石羊河流域进行了专程调研 ,所见所闻令人忧心。石羊河流域人口与水资源的矛盾突出、生态环境严重恶化、民勤绿洲岌岌可危 ,如不采取有力措施、加强治理保护 ,民勤会很快变为第二个罗布泊！一、生态环境上存在的突出问题石羊河流域是我国水资源最紧缺的地区之一 ,目前人均水资源量仅为６２７ｍ３。究其原因 ,一是来水减少 ,二是需水量急剧增加 ,三是用水技术落后。当地群众总结为“上游流失水、中游浪费水、下游蒸发水、城市污染水”。由于水资源十分短缺 ,引发了一系列的生态环境问题 ,局…     

汾河流域生态环境需水与水资源安全问题研究

根据所估算的汾河流域生态环境需水量提出了该河上、中、下游地表水的合理开发利用率,即对径流量的利用应限制在多年平均径流量的18%4、4%和34%以内.针对长期过度开发引起的水资源安全问题,探讨解决汾河流域生态环境需水问题,维护流域水资源安全的方案和设想.     

黑河流域（干）水资源优化利用

以黑河流域（干）水资源基本特征和水资源开发利用现状及其对生态环境的影响为基础，根据上、中、下游统筹兼顾，经济效益、生态环境效益和社会效益相结合的原则，提出并建立了基于动态规划法的流域水资源优化利用方案和优化管理数学模型。结果表明，动态规划法对解决水资源供需矛盾等问题是可行的。     

浅谈乌鲁木齐河流域水环境问题及保护对策

文章在分析乌鲁木齐河流域水环境现状的基础上,针对该流域水环境面临的问题,论述了加强乌鲁木齐河流域水环境保护的重要性和必要性,并提出保护乌鲁木齐河流域水环境及生态环境的一些对策与建议,以期实现其社会经济、水资源与生态环境之间的协调发展.     

石羊河流域生态环境恶化及水资源利用现状浅议

石羊河流域生态环境恶化的主要原因是流域内水资源的严重匮乏所致,因此,分析流域水资源利用中存在的问题,并提出相应措施,对石羊河流域生态环境治理具有重要意义。本文介绍了石羊河流域的生态环境恶化的现状、成因及流域治理水资源利用中存在的问题,并针对水资源利用中存在的问题提出了几点建设性意见。     

改善石羊河流域生态环境的途径

石羊河流域生态环境恶化问题已引起党和国家领导人的高度重视,温家宝总理亲自批示“：绝不让民勤成为第二个罗布泊”,要改善生态环境,首先必须解决水的问题,在跨流域调水工程近期不能实施的前提下,推广高新节水技术、实现全流域水资源统一管理、严格实行计划生育政策,对生态恶化的地区实行生态移民,减轻生态环境压力、人工绿洲区实行调整农作物结构,推广抗旱节水新品种、工业上大力发展循环经济,提高水资源的重复利用率等措施是改善石羊河流域生态环境的正确途径。     

从水资源看黑河流域的生态变化及防治

在分析黑河流域水资源开发利用现状的基础上,阐明了近年来由于中游地区用水量的增加,造成下游水资源短缺,使原已很脆弱的生态环境日趋恶化,一系列生态问题不断涌现,威胁着下游绿洲的生存.提出当前黑河流域生态环境恶化是由人们不合理利用水资源所造成的,其原因是人为的,同时提出了现阶段防治下游生态环境恶化的基本措施,以供流域综合规划参考.     

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.     

An Analysis of Catherine＇s Character——Wuthering Heights

Wuthering Heights, Emily Bronte＇s only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.     

Lower Paleozoic oil relationships within Williston Basin, Canada

The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.     

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.     

Design and analysis of generic LBS application developing platform

Location based services is promising due to its novel working style and contents.A software platform is proposed to provide application programs of typical location based services and support new applications developing efficiently. The analysis shows that this scheme is easy implemented, low cost and adapt to all kinds of mobile nework system.     

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