水镁石纤维水泥混凝土工作性研究

为了解决水镁石纤维的加入使水泥混凝土的流动性差,导致其无法充分发挥其增韧作用的问题,通过混凝土坍落度试验,利用灰色关联分析方法分别研究了水镁石纤维等级、用量、减水剂种类、减水剂纤维比等因素对水泥混凝土工作性能的影响.结果表明,对水镁石纤维混凝土影响程度最大的是水灰比和纤维长径比(水镁石纤维等级),其次是减水剂纤维比,影...     

输煤皮带机尾粉尘污染及气动射雾除尘

为对选煤厂输运皮带机尾粉尘污染进行控制,对皮带机尾粉尘颗粒运动及机尾处作业空间粉尘质量浓度扩散进行相关的数值仿真.利用气-尘-液多相流理论,对粉尘颗粒运动进行数值分析,得出皮带机尾处粉尘污染规律,实测数据验证了数值模型的正确性.提出针对机尾粉尘逸散特性的气动射雾除尘方案,确定了除尘技术参数.研究结果表明:粘附在机尾表面的浮尘是机尾的发尘源,滚筒离心力和风流剪切力是尘源飞扬的动因;对机尾皮带进行封闭是除尘的前提条件,在密封罩内设置气动射雾使得封闭罩内形成雾池,粉尘在过饱和湿空气状态下被迅速捕捉沉降.     

城市水体氮污染类型及同位素溯源研究

城市中各类含氮污染物的排放对环境产生了各种危害,明确氮污染的来源及循环规律可为环境治理提供一系列的专业依据.文章阐述了氮污染的机理、产生的危害、城市水体氮污染现状及污染类型,综述了城市水体氮污染溯源研究的最新进展.地表水主要受总氮、硝态氮和铵态氮污染影响,大部分水体仅满足Ⅳ～Ⅴ类水质标准,人为活动是城市水体氮污染的主要贡献者.此外,更进一步对水体氮污染来源示踪技术（水化学分析法、同位素示踪法、微生物源追踪技术（MST）及同位素源解析模型等）和端元物质中硝酸盐氮氧同位素特征值进行汇总,为氮污染溯源和明确氮污染迁移规律提供了可靠的依据.本综述对城市水体的氮污染溯源及氮污染防治工作具有重要意义.     

水镁石纤维路面混凝土路用性能

通过力学试验和扫描电镜微观分析,对水镁石纤维的适用性以及水镁石纤维混凝土制备关键参数进行了优化试验,并对水镁石纤维混凝土与普通水泥混凝土的力学性能、疲劳、耐磨性和抗冻性的试验结果进行了对比分析。结果表明：水镁石纤维适用于路面混凝土;水镁石纤维湿法掺加工艺优于干法,外加剂优选为引气作用较强的D型减水剂,水镁石纤维最佳掺量（质量分数）为4%;水镁石纤维混凝土较普通水泥混凝土在抗弯拉强度提高的同时,刚度降低,韧性上升,耐疲劳与抗冲击等动力学性能均有改善,抗冻、抗渗、耐磨、抗腐蚀等性能均有一定幅度的提高;纤维的阻裂机制、增强作用和微集料效应,提高了水镁石纤维混凝土路面的耐久性能。     

水镁石纤维路面混凝土路用性能

通过力学试验和扫描电镜微观分析,对水镁石纤维的适用性以及水镁石纤维混凝土制备关键参数进行了优化试验,并对水镁石纤维混凝土与普通水泥混凝土的力学性能、疲劳、耐磨性和抗冻性的试验结果进行了对比分析。结果表明：水镁石纤维适用于路面混凝土;水镁石纤维湿法掺加工艺优于干法,外加剂优选为引气作用较强的D型减水剂,水镁石纤维最佳掺量（质量分数）为4%;水镁石纤维混凝土较普通水泥混凝土在抗弯拉强度提高的同时,刚度降低,韧性上升,耐疲劳与抗冲击等动力学性能均有改善,抗冻、抗渗、耐磨、抗腐蚀等性能均有一定幅度的提高;纤维的阻裂机制、增强作用和微集料效应,提高了水镁石纤维混凝土路面的耐久性能。     

沙尘暴期间运动尘颗粒对高压输电导线施加的应力预测

针对沙尘暴期间输电导线动力学行为分析中运动粉尘颗粒对高压输电导线施加的应力预测,以引入的粉尘颗粒与输电导线的碰撞概率为基础,应用弹性碰撞模型和颗粒运动方程对碰撞时间予以定量预测,提出一种基于粉尘颗粒和输电导线尺度、粉尘质量浓度及流场作用的粉尘颗粒对输电导线施加应力的计算方法 .揭示了以上因素对应力的影响规律:应力随粉尘颗粒的速度近似呈线性增大;随输电导线的半径近似呈线性增大;随粉尘颗粒的半径近似呈指数形式减小.结果表明,在输电线路设计中,不仅要考虑风荷载,还需考虑运动粉尘颗粒的作用.     

腾格里沙漠晚更新世以来湖相沉积年代学及高湖面期的初步确定

对腾格里沙漠古湖泊沉积和地貌的考察及对典型代表剖面初步研究结果表明，一个连续而巨大的淡水湖泊高水位形成于距今３．９～３．６万年前．在距今３．３～２．３万年期间，腾格里沙漠西北部曾存在一面积至少达１６２００ｋｍ２、水深２５ｍ（白碱湖，最大水深超过６０ｍ，分布于大海子一带）的淡水湖泊．大量的瓣鳃类、腹足类化石及介形类化石组合的存在表明该时期湖泊水温不低于１０℃，由此把该时期的湖泊暂且称“腾格里大湖”（ＭｅｇａｌａｋｅＴｅｎｇｇｅｒ）     

纤维水镁石对水泥硬化浆体力学性能的影响

采用SEM,XRD和电阻率测定仪研究了纤维水镁石对硅酸盐水泥硬化浆体的力学增强机理.结果表明,由于添加具有高拉伸强度和高杨氏模量的纤维水镁石,在水泥硬化浆体原有网络结构的基础上又建立了一个新的网络结构,改进了基体材料的界面结构,同时,纤维水镁石和水泥基体材料同属极性物质,在水化开始后水镁石纤维表面被水化产物C-S-H凝胶所覆盖,表明其具有良好的物理相溶性,这种双重作用提高了水泥硬化浆体的物理力学性能.     

磷肥的施用造成的面源污染

随着城市点源污染得到逐步的控制，农业面源污染已经越来越成为水体富营养化的主要污染源。本文简要地概述了农业面源污染中磷肥的施用在水体富营养化中所起的作用以及防治农业面源污染的困难，建立稳定、和谐与良性循环的农业生态系统是治理农业面源污染的长久之计。     

稻虾共作模式下水体及土壤氮磷变化特征研究

稻虾共作模式是一种新型的生态种养模式,研究不同生长阶段水体及土壤氮磷含量的变化特征对农业面源污染防治具有指导意义.以江西省新建恒湖垦殖场稻虾基地为研究对象,分别于不同生长期采集灌溉水、田间水、排水及土壤,检测3类水体及土壤中的硝态氮、铵态氮、总氮及总磷的含量.结果表明:水体中氮磷等物质均为排水>田间水>灌溉水,铵态氮及硝态氮在抽穗期及灌浆期远高于其他生长期,总氮在整个生长周期中变化不大,总磷为逐渐上升;土壤中硝态氮在分蘖期及成熟期最大,土壤全氮在成熟期最大,土壤铵态氮及全磷变化不明显.可见,应针对不同生长期合理施肥,在抽穗期及灌浆期减少肥料的投入,同时加强农田排水氮磷的防控.     

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.     

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