论流域水土保持中水保与土保的关系

为揭示水土保持中＂水保＂和＂土保＂的关系,运用水资源结构分析方法,探讨了流域＂水流失＂的内涵.在此基础上,以安塞纸坊沟为例,利用土壤侵蚀的特征指标和水流失的特征指标分别表征土壤侵蚀和水流失,分析了水流失与土壤侵蚀之间的关系,并对不同目标下的水土保持用水进行了讨论.结果表明：水流失本质上就是流域生态环境水向潜在资源水和灾害水转化的过程;1938—1999年间纸坊沟流域水流失与土壤侵蚀的强度与程度之间均有较好的相关关系;纸坊沟流域土保可达到微度侵蚀的目标,此时的径流量约为6.77×10^4m^3,基本可满足河道生态环境需水以及一定社会经济用水的需求.     

基于GIS的天水罗玉沟流域土壤侵蚀强度评价

以天水罗玉沟流域为评价区域,采用高分辨率遥感图像解译和野外调查相结合的方法提取土地利用信息,同时结合土壤类型信息计算出该流域的植被覆盖度.利用GIS技术对1∶1万地形图建立数字高程模型(DEM),进而提取地形坡度,经过数据综合分析,建立了土壤侵蚀强度评价模型.结果表明,该流域42.34%的区域属于强烈及强烈以上侵蚀区,土壤侵蚀严重.主要原因是该区域属浅切割区,质地较软,抗蚀力弱.     

冀西北地区(坝下)土壤侵蚀卫星遥感应用研究

利用Landsat-5TM图像,分别进行影响土壤侵蚀的各因素解译和基本侵蚀图斑的解译,然后,采用多因子多层次综合评判方法,确定出土壤侵蚀强度等级,进而分析了冀西北山间盆地土壤侵蚀现状以及土壤侵蚀发展趋势.     

基于Pleiades影像的东北黑土区沟蚀分异特征研究

以Pleiades遥感影像为数据源,获取东北典型黑土区2013年的侵蚀沟分布数据,并根据研究区范围内1∶10 000的数字高程模型(digital elevation model,DEM)数据提取坡度、坡向和坡形等地形因子,探讨了各地形因子影响下的侵蚀沟密度与强度规律,全面分析了东北典型黑土区沟蚀分异特征.结果表明:研究区内侵蚀沟总体分布较均匀,但在东北部地区侵蚀沟分布较密集;沟壑密度与强度随坡度的增加总体上呈先增大后减小的趋势,在5°~10°范围内沟壑密度与强度达到最大;研究区中西南、南以及东南三个坡向上的沟壑密度与强度远大于其他坡向,东北和北坡沟壑密度与强度最低;研究区内凹形坡侵蚀沟发生的概率几乎是凸形坡的2倍,直线坡沟壑侵蚀发生的概率最低,且研究区沟蚀密度和强度均与地形具有相关关系.     

关中中东部地区土壤侵蚀评判研究

从土壤侵蚀的环境背景入手，划分了关中中东部地区的土壤侵蚀类型。以侵蚀类型为单元，依据侵蚀因子与侵蚀强度的关系建立了侵蚀强度评判模式，进而利用流域输沙模数对评判结果进行了检验，符合区域土壤侵蚀评判的精度要求。最后总结了侵蚀强度分布规律。     

皖西大别山区土壤侵蚀空间分布特征及与地形的关系

基于修正的通用土壤流失方程和GIS空间分析方法,定量分析了皖西大别山区土壤侵蚀空间分布特征,讨论了侵蚀强度与海拔、坡度、坡向等因子的关系.基于信息熵模型评价地形因子与土壤侵蚀强度的空间相关性结果表明:(1)皖西大别山区2010年土壤侵蚀总量为1844.30×10~4t,平均侵蚀模数为1415.05t/km~2·a.区域以微度和轻度侵蚀为主,分别占总面积的52.95%和31.99%,侵蚀强度由东南至西北逐渐加剧.(2)坡度和海拔主导着区域内土壤侵蚀强度的空间分布.随着坡度和海拔增加,侵蚀强度不断加剧,强度侵蚀的面积比例增加,微度侵蚀的面积减少;在坡度15-25°区域、海拔200-500m区域的土壤侵蚀总量最大.坡向对土壤侵蚀强度的影响较小,土壤侵蚀强度在东南坡向较其它坡向略强.(3)地形因子与土壤侵蚀强度的空间相关性强弱为:坡度海拔坡向.坡度是安徽省大别山区土壤侵蚀强度的主导因子.     

湟水流域土壤侵蚀评估

以湟水流域为研究对象,基于USLE模型评估土壤侵蚀强度,并探讨不同土地利用类型、海拔和坡度下,土壤侵蚀强度的变化规律。结果表明:湟水流域土壤侵蚀模数为523.8t/(km2·a),属于轻度侵蚀。     

黄河流域土壤侵蚀快速评估

在前期研究的基础上,将基于最小图斑的土壤侵蚀快速评估方法应用到黄河流域土壤侵蚀的评估中,建立了土壤侵蚀特征指标(EI)与土壤侵蚀强度E之间的判别分析关系,并根据判别函数判断EI的归属类别,从而获得每个图斑的土壤侵蚀强度.经敏感性分析,说明评估结果是稳定可靠的.应用表明,土壤侵蚀特征指标能够较好地表征流域土壤侵蚀强度;土壤侵蚀快速评估方法在实际应用中具有明显优势,不仅对输入数据和参数要求相对较低,而且能够提高模型的评估效率.     

DEM精度对土壤侵蚀评价的影响

选取位于东北黑土区的拜泉县为研究区,以高精度的DEM(1∶1万比例尺)为基准,探讨低精度的DEM(1∶5万比例尺)提取地形因子的差异及其对土壤侵蚀评价的影响。结果表明:在拜泉县的西南平原和缓坡台地区、三河(双阳河、通肯河、润津河)沿岸低洼易涝区,1∶5万DEM提取的L因子分别高估11%和25%,提取的S因子则低估25%和31%。在西北和中部漫岗丘陵区、东南丘陵和台地区,L因子分别低估20%和7%,S因子分别低估16%和12%。地形因子的差异所带来的土壤侵蚀评价也有差异,其中在平原区差异较小(为10.67%),但在丘陵区差异较大(达23.14%)。因此,在土壤侵蚀评价中,在高精度的DEM难以获取的情况下,平原区可用较低分辨率的DEM来代替;但在丘陵区则不能代替,或者须对其计算的LS因子进行必要的修订,从而在一定程度上保证土壤侵蚀评价的精度。     

浅谈阿品德小流域水土保持工程设计

阿品德小流域土壤侵蚀的类型随流域的地形、地貌等自然条件的变化而不同,在流域上游及源头,植被覆盖率20～40%左右,侵蚀类型主要为水力侵蚀,侵蚀强度为轻度。流域内地面坡度陡,土层深厚,土壤容易被水流冲刷,加之人为开垦耕地,草场退化较为严重。     

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     

Call for Papers

<正>"The Journal of Shanghai Normal University:Mathematics"is published by Shanghai Normal University as regular issues of The Journal of Shanghai Normal University each year from 2014 in English.The editors-in-chief of the issues are professors Yuhao Cong and Maoan Han.The Journal of Shanghai Normal University was started in 1958 with