甘肃敦煌西湖国家级自然保护区湿地现状及其保护对策研究

系统阐述了甘肃敦煌西湖国家级自然保护区湿地资源的特点和现状,分析了保护区内湿地保护和利用面临的问题,提出恢复和重建湿地生态系统、制定区域保护计划、正确处理湿地资源保护和开发的关系、加强宣传增强保护意识等一系列措施,以期为甘肃敦煌西湖国家级自然保护区湿地资源的保护提供科学依据。     

中国若尔盖高原湿地的生态补偿基线研究

本文选择我国甘肃尕海—则岔、甘肃黄河首曲和四川若尔盖3处国家级自然保护区作为若尔盖高原湿地研究区,构建委托-代理框架探究影响牧民保护湿地积极性的因素,运用耦合群落调查法和遥感解译法完成了若尔盖高原湿地边界的遥感制图,旨在研究我国若尔盖高原湿地的生态补偿基线.结果表明:研究区高原湿地面积约为1 463km2,其生态系统服务价值为274.29亿元,湿地生态补偿标准应以每亩110元为下限,1.25万元为上限,实施过程中综合考虑牧民年均收入、其他保护相关成本等因素.     

敦煌大泉河水环境特征分析

以位于敦煌盆地南部莫高窟区的大泉河为例,分析了极干旱环境条件下小河流的基本特征,研究了该河流的径流量和水质成分的时空变化规律,其目的是合理有效地开发利用戈壁荒漠区极珍贵的水资源,兴利避害,为敦煌莫高窟的保护及旅游事业发展提供服务.     

基于RS/GIS的斧头湖湿地演变及其驱动力研究

研究湿地景观的动态变化及原因是有效保护湿地资源、合理制定利用与保护湿地政策的关键.采用ERDAS、ArcGIS等软件对1991年、2005年7月的湖北斧头湖区遥感影像图进行解泽,确定斧头湖湿地类型现状,描述湿地类型动态变换.结果表明:(1)研究期内湿地景观类型发生了较大幅度的变化,其中湖泊及滩地面积缩减较为严重;(2)...     

颍州西湖国家湿地公园生物多样性及保护对策研究

颍州西湖国家湿地公园的良好生境为多种生物提供了生存和繁衍条件,动植物资源丰富。西湖湿地保护面临面积不断减少、环境污染、生物资源利用不合理、经费不足、科研薄弱及城镇化、旅游开发对生境影响等问题。提出恢复植被、退田还湖、防治污染、完善法规、增加投入、加强科研与宣传、促进社区经济发展等湿地保护建议。     

基于RS/GIS的斧头湖湿地演变及其驱动力研究

研究湿地景观的动态变化及原因是有效保护湿地资源、合理制定利用与保护湿地政策的关键.采用ERDAS、ArcGIS等软件对1991年、2005年7月的湖北斧头湖区遥感影像图进行解泽,确定斧头湖湿地类型现状,描述湿地类型动态变换.结果表明:(1)研究期内湿地景观类型发生了较大幅度的变化,其中湖泊及滩地面积缩减较为严重;(2)研究区内居民点面积处于加速扩张过程,是湿地景观格局空间变化的关键影响因素;(3)研究期内不同湿地类型的动态变化特征差异显著,其中人工湿地类型双向动态变化较为明显,湖区湿地受人为干扰较严重.长江水位变化及长江入湖口堵塞是引起这种变化的自然原因;围湖造田与精养鱼池扩建是引起这种变化的主要人为因素.     

额尔齐斯河河谷沿岸湿地植被调查

采用定点、选取典型样线和样地的植物调查方法对额尔齐斯河河谷的湿地植被进行了实地的调查。2010年植被调查样点106处,2011年共选的典型样线5个、植被调查样点94处。利用野外采样数据并结合2010年该区遥感影像对额尔齐斯河河谷的湿地植被进行区系划分;对研究区湿地自然植被的类型特征及分布情况进行了分析;归纳影响研究区湿地植被分布的影响因素,同时提出研究区湿地植被保护的相关措施。结果表明：额尔齐斯河河谷沿岸湿地的植被可分为4个植被类型,10个植被亚型,20个群系。     

敦煌盆地生态脆弱区缓变型地质灾害及保护对策

运用生态地质学系统方法,通过对敦煌盆地内生态地质环境问题进行调查分析,主要存在月牙泉湖水位下降、天然绿洲和湿地萎缩,以及土地盐渍化、沙漠化等缓变型地质灾害.结合干旱区生态特征分析认为农业生产与水系统循环密切关联,水土平衡矛盾是主要控制因素.恢复敦煌河道自然水循环系统,建立合理水土的开发利用方式,是缓解盆地内上述地质环境问题的有效对策.     

面向对象的黄河源典型区湿地信息提取

以黄河源玛多县为实验区,遥感TM影像和DEM为数据源,在研究区湿地定义、成像机制及其地学规律分析的基础上确定了湿地遥感提取的分类体系和湿地信息提取的有效特征（包括光谱、纹理、地形和结构特征）,并构建了面向对象的遥感湿地提取方法.实验显示:该方法湿地提取的总精度为90.13％,Kappa系数为88.33％,比常用的最大似...     

一种新的湿地信息遥感提取方法研究

针对多光谱影像水体信息提取,结合湿地遥感自身特点,提出了一种基于湿度分量与水体光谱特征的湿地信息提取方法.与传统单波段阈值法、谱间关系法等水体提取方法相比较,此算法不仅适合于开敞水体的提取,还将滩涂、芦苇沼泽地等湿地信息同时提取出来,然后利用建立的湿地分类决策树模型,实现了研究区湿地信息分类提取.     

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.     

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