化学法制备高纯碲过程中杂质元素脱除的热力学分析

通过对Te(Ⅳ)-Pb(Ⅱ)-Cu(Ⅱ)-As(Ⅲ)-H2O和Te(Ⅳ)-MeS-H2O系热力学分析,得到溶液中Te(Ⅳ),Pb(Ⅱ),Cu(Ⅱ)和As(Ⅲ)离子总浓度与溶液pH值、温度以及溶液中S2-浓度的关系。热力学分析结果表明:采用硫化物沉淀法可以深度净化Na2TeO3溶液,去除其中大部分重金属离子及砷离子,确定理论上去除Na2TeO3溶液中Pb(Ⅱ),Cu(Ⅱ)和As(Ⅲ)离子的最佳pH值为11左右。采用硫化物沉淀法对Na2TeO3溶液中Pb(Ⅱ),Cu(Ⅱ)和As(Ⅲ)离子的净化实验验证了热力学分析的正确性,通过实验使粗TeO2中的Pb,Cu和As杂质的质量分数由0.273 0%,0.165 9%和0.280 0%分别降低到3.24×10-4%,1.00×10-4%和1.30×10-3%,但S2-浓度过量对As的去除不利。实验确定硫化沉淀法去除杂质离子的最佳条件是:pH=11,温度为373 K,反应时间为50 min。     

污水生物处理工艺对重金属离子的去除特性分析

以福州市A、B两座污水处理厂为研究对象,Mn、Fe、Ni、As、Cr为检测项目,对各重金属元素的去除特性与去除机制进行分析讨论.研究结果表明:1两座污水处理厂进水重金属离子污染情况不严重,仅Mn、Fe含量略高,可能与福州地区环境背景有关;2以A/O工艺作为生物单元的A污水处理厂对重金属离子的去除率在49.3%(Mn)至93.1%(Fe)之间,以CASS工艺为主的B污水处理厂去除率整体上劣于A污水处理厂,各重金属离子的去除率在28.5%(Mn)至88.2%(Fe)之间;3在城市污水生物处理过程中,重金属去除主要依赖于生物单元,物理单元的去除作用不显著;4预测两座污水处理厂对各重金属离子的去除能力为0.03~18.10 kg·d-1.     

改性表面增强拉曼基底对几种重金属的定量检测

重金属离子对水质及其应用有着严重的影响,开发高选择性及灵敏度的重金属离子检测平台在水资源保护中有着重要的意义。采用4-巯基苯甲酸功能化金纳米粒子为载体制备的表面增强拉曼(SERS)溶胶基底,对水溶液中Pb~(2+)、Cd~(2+)、As~(3+)等重金属离子具有较强的选择性和较高的灵敏度。实验发现,SERS基底对Pb~(2+)、Cd~(2+)和As~(3+)的拉曼检测光谱在1 047、1 075、1 587cm~(-1)附近有着明显的振动频带位移及峰强变化。通过对溶胶基底优化得到了性能优异的增强基底,能够实现对3种重金属离子的区分,对重金属的检出限可达0.1mg/L,并在0.5～100mg/L范围呈线性关系,并成功的对真实水样中Pb~(2+)进行了加标验证实验。该基底提供了一个快速、便捷的重金属鉴别检测方法,且具有较好的增强效果和重金属定量分析能力,为水中重金属离子的高效检测提供了有效手段。     

经修饰的桔子皮对重金属Zn~(2+)的吸附研究

传统去除重金属离子的方法很多,但都存在某些不足之处,而生物吸附法因其材料易得,价格低廉,去除效果好而受到人们的青睐。本文通过桔子皮生物吸附剂对锌离子吸附动力学、最大吸附量的研究可以得到以下结论:桔子皮生物吸附剂对锌金属离子的吸附可以分成三个阶段。桔子皮生物吸附剂吸附重金属锌离子的最大吸附量的吸附等温线都非常符合Langmuir方程(R2=0.92-0.98)。     

特殊环境条件下复合重金属污染固化土中离子迁移特性分析

运用有限元软件建立二维轴对称分析模型,研究了重金属离子(Cu2+,Cd2+)在土壤中的迁移扩散规律,对比了单一重金属离子(Cu2+)和复合重金属(Cu-Cd)的迁移特性,分析了固化前后重金属的扩散规律,并考虑了温度和干湿作用的影响。结果表明:复合重金属在渗透过程中的迁移半径大于单一重金属离子的迁移半径;固化后的污染土对于重金属离子的扩散速率有着良好的控制作用,固化作用对单一重金属离子扩散的影响更为明显。环境温度对于重金属离子的扩散速率和范围呈现出正相关的影响;干湿循环作用下重金属离子的扩散范围明显增大。     

大同风化煤净化含重金属离子废水的研究

本文报导了用大同风化煤研制和开发一种在水中无腐植酸溶出、有较高去除水中重金属离子能力和一定强度的粒状炭质净化剂的工作。经试验证明,大同风化煤对不同金属离子的净化次序为: Pb~(2 )>Hg~(2 )>Fe~(2 )>Cu~(2 )～Cd~(2 )>Zn~(2 )>Ca~(2 )>Ni~(2 )>Mg~(2 )>Cr~(3 )。该净化剂价廉易得,效果良好,可用作处理含重金属离子废水,以期控制污染、回收金属和水的再用。本文也初步探讨了净化剂去除镍离子的机制,这将有助于这种新型净化剂的开发。这里讨论了除Ni~(2 )过程的主要因素:总酸性基团含量和碘吸附率。     

酸性氯化亚铁废水的处理与资源化研究

应用络合萃取法与沉淀法分离钢丝绳企业氯化亚铁废水中的重金属元素锌与铅,分析了废水体系中金属离子的存在形态,探讨了不同实验条件对处理效果的影响,得出最佳处理工艺条件为:以甲苯为稀释剂、YF1为络合剂对重金属元素锌进行萃取分离,络合剂浓度为0.5 mol/L,油水体积比(O/W)为0.4∶1,使用1 mol/L NaOH溶液作为反萃剂,锌离子将以四羟基合锌酸根离子的形式转移到反萃水相中;同时研究了萃取剂YF1萃取锌的机理,最终萃合物组成为(YF1)2.H2ZnCl4;选择YF2(0.5 mol/L)作为沉淀剂去除废水中的重金属元素铅,沉淀剂与废水的最佳体积比为0.04∶1.处理后的高浓度氯化亚铁溶液中锌与铅的浓度均达到10×10-6以下,符合相关企业的质量指标,从而实现了酸性氯化亚铁废水的治理与资源化.     

CS-g-PMMAPANNHNH2水处理剂的应用研究

运用静态法和动态法研究了自制改性淀粉CS-g-PMMAPANNHNH2对重金属离子的吸附去除能力.结果表明,在重金属离子单独存在或共存时,CS-g-PMMAPANNHNH2对Pb2+、Cr6+、Cd2+、Cu2+、Mn2+、Zn2+等金属离子都具有较好的吸附效果,最高吸附率可达99%.同时,利用CS-g-PMMAPANNHNH2对实际含Pb和含Cu、Pb的废水进行了处理,结果表明,CS-g-PMMAPANNHNH2是一种很好的水处理剂,对Pb2+、Cu2+等重金属离子具有很好的吸附效果,具有实际应用和推广价值.     

经修饰的桔子皮对重金属Zn2+的吸附研究

传统去除重金属离子的方法很多,但都存在某些不足之处,而生物吸附法因其材料易得,价格低廉,去除效果好而受到人们的青睐.本文通过桔子皮生物吸附剂对锌离子吸附动力学、最大吸附量的研究可以得到以下结论:桔子皮生物吸附剂对锌金属离子的吸附可以分成三个阶段.桔子皮生物吸附剂吸附重金属锌离子的最大吸附量的吸附等温线都非常符合Langmuir方程(R2=0.92-0.98).     

重金属离子对高岭土物理力学性质的影响研究

通过试验分析了三种常见且危害性较大的重金属离子(Pb²⁺、Zn²⁺、Cu²⁺)单独作用和共同作用时，其对高岭土物理力学性质的影响规律.研究结果表明：不论是单一重金属离子污染高岭土还是多种重金属离子污染高岭土，其液塑限、塑性指数、抗剪强度均会随着重金属离子浓度的增加而降低，其渗透系数则均会随着重金属离子浓度的增加而增加；多种重金属离子对高岭土液塑限、抗剪强度以及渗透性的影响程度要大于单一重金属离子的影响程度，但要小于单一重金属离子影响程度的总和，且重金属离子浓度越大，这种效应就越明显，因此不能用单一重金属离子污染土的工程特性推求多种重金属离子污染土的工程特性.     

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     

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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Brief Introduction to “Journal of Jilin University( Science Edition) ”

<正>"Journal of Jilin University(Science Edition)"is a comprehensive academic journal in the fields of science sponsored by Jilin University and administrated by the Ministry of Education of the Peoples Republic of China.The journal started publication in 1955.The original name at starting publication was"Journal of Natural Science of Northeast People University",which was changed into"Acta Scientiarum Naturalium Universitatis Jilinensis"in 1958 owing to the name change of the university.The present journal name has