长江口影响水资源承载力关键指标与临界条件

中国幅员辽阔,区域气象水文条件差异极大,社会经济发展不均衡,水资源问题极其复杂。因此,需根据不同水文分区,明确区域的水资源问题,识别区域水资源承载力的制约要素,提出物理机制明确且能反映水文机理的影响承载力关键指标及其对应的临界条件。该文以长江口为例,从问题产生的机理出发,识别出入海径流为河口水资源承载力的关键指标和水文要素,提出定值方法,结合动力学模型模拟长江口盐度场,确定长江口抵御咸潮入侵的入海径流的临界条件,以此作为水资源承载力的刚性约束,为不同水文分区展开类似工作提供借鉴。     

长江口南港河段洪季水质底质综合评价

本文根据1985年7月洪水期长江口南港河段水文、水质同步调查所提供的水质底质资料将二者综合进行多要素的环境质量评价,因该区段水质中的铜全部超标,故采用含铜和不含铜两种情况进行对比,各污染物权重值根据P_(ij)主成分——因子分析法加以确定。评价结果表明,该区段水质底质大部分介于尚清洁和微污染。局部地区出现轻污染,较客观地反映了实际情况。     

长江口南港河段洪季水质底质综合评价

本文根据1985年7月洪水期长江口南港河段水文、水质同步调查所提供的水质底质资料将二者综合进行多要素的环境质量评价,因该区段水质中的铜全部超标,故采用含铜和不含铜两种情况进行对比,各污染物权重值根据P_(ij)主成分——因子分析法加以确定.评价结果表明,该区段水质底质大部分介于尚清洁和微污染.局部地区出现轻污染,较客观地反映了实际情况.     

长江口区沉积地球化学特征的定量研究

对长江口区３２个表层样的２８种元素进行数理统计分析，并结合该区的水文、地貌和沉积环境等背景资料，探讨长江口区沉积物的元素地球化学特征。Ｑ型聚类分析结果表明长江口可划分为四大沉积地球化学区，Ｒ型因子分析揭示了控制长江口区元素来源和分布的主要因素。     

水文要素在桥墩基础防护监测方案中的应用

必要和充分的水文要素监测,对于桥墩基础水下施工的进度及质量控制具有非常重要的意义。以广东九江大桥为例,通过先进的水文监测手段,对桥墩附近水下地形开展地貌及地质状况的监测,同时结合水位、流速变化等水文要素的综合分析研究,为桥墩基础冲刷防护监测的确定和调整提供技术依据。     

长江口北槽悬沙输移机理分析

运用通量机制分解法对长江口北槽深水航道的实测水文泥沙资料进行了分析,将悬沙通量分解成了8个动力项,从平流输沙、潮泵效应输沙和垂向净环流输沙三方面综合分析了长江口北槽的悬沙输移特征。研究结果表明:在水文资料实测年份时,北槽输沙主要来源于上游来沙;平流输沙项占总体净输沙的比重最大;潮泵输沙所占比例较小;航道内的各测点的垂向净环流输沙主要受欧拉余流控制;深水区悬沙含量垂向变化明显,河口浅水区,表底余流方向不同,垂向净环流输沙作用增强。     

水文综合智能仪及其在潮水河水文测验中的应用

水文综合智能仪及其在潮水河水文测验中的应用姜德保，水文，１９９２年第４期水文综合智能仪既能采集脉冲数字量信息，又能采集模批量信息。由程序控制自动进行流速、流向、水温等多种水文要素的测量、记录、存贮和计算。现场测量一结束，便可提供所有测量资料和全部计算...     

长江口咸淡水混合及其对悬沙的影响

本文应用现场实测水文资料,讨论了长江口咸淡水混合及潮差、高潮位的关系以及在不同潮相时各种混合动力机制的相对重要性。还从混合产生的环流效应、絮凝作用、层化界面等方面分析了长江口悬沙输移和聚集的原因,并用二维盒子模型计算验证了环流对河口泥沙聚集的效应。本文的结论深化了以往对长江口混合的认识,具有理论意义和实际应用价值。     

长江口咸淡水混合及其对悬沙的影响

本文应用现场实测水文资料,讨论了长江口咸淡水混合及潮差、高潮位的关系以及在不同潮相时各种混合动力机制的相对重要性.还从混合产生的环流效应、絮凝作用、层化界面等方面分析了长江口悬沙输移和聚集的原因,并用二维盒子模型计算验证了环流对河口泥沙聚集的效应.本文的结论深化了以往对长江口混合的认识,具有理论意义和实际应用价值.     

长江口河水氯离子浓度指标值的建模与预报

长江口宽度大叉道多，影响潮流运动的因素错综复杂，且各种变化量的实测资料有限，面对如此一个复杂的非线性随时间变化且实测资料有限的系统，利用传统的方法分析研究系统的建模、预报有一定的强求和困难。作者尝试利用在八十年代后期得到飞速发展的人工神经网络现代技术分析研究长江口河水氯离子浓度指标值的动态变化规律。所采用的模型集是多层映射的BP神经网络，利用长江口水文观察站的水文观察资料，采用误差反向传播学习方法来调整BP网络参数连接权值和节点阀值。经过训练学习后的BP神经网络输出与量测输出是非常接近的。并考虑三峡水库建成后有不同的调水方案，用得到的BP神经网络模型分别来与博爱长江口河水日平均氯离子浓度值的变化情况，所得结果供上海有关部门自来水公司做决策参考。     

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.     

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     

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     

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     

Journal of Donghua University ( English Edition) Contents of Volume 31

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