交联壳聚糖/聚羟基铝改性蒙脱土对水中Cu~(2+)和Pb~(2+)的竞争吸附

以交联壳聚糖和Al13高聚体共同改性所制得的交联壳聚糖/聚羟基铝改性蒙脱土为吸附剂,采用吸附竞争系数描述其在水溶液中对Cu2+、Pb2+的竞争吸附。结果表明,Cu2+、Pb2+存在于水溶液中被吸附时表现为拮抗效应,且此效应显著程度随pH升高而减弱;改性蒙脱土对两种金属离子的吸附选择性顺序为:Cu2+Pb2+。某种金属的吸附量在另一种金属初始浓度增加时基本不变,低浓度条件下,吸附竞争系数受浓度影响较大;离子强度增大促进改性蒙脱土对Cu2+、Pb2+的吸附;Cu2+、Pb2+的竞争吸附行为更符合Freundlich方程。     

天然高岭土对Pb~(2+),Cd~(2+),Ni~(2+),Cu~(2+)的吸附及解吸性能研究

探讨了吸附时间、溶液pH、重金属离子初始质量浓度、离子强度以及竞争吸附等因素对天然高岭土吸附水中Pb2+,Cd2+,Ni2+,Cu2+等重金属离子的影响.结果表明,pH、初始质量浓度、离子强度以及共存离子,是影响高岭土吸附重金属离子的主要因素;高岭土对Pb2+的吸附性能明显优于其它3种重金属离子,顺序为:Pb2+＞Cd2+＞Ni2+＞Cu2+;吸附等温线均符合Freundlich型等温方程,说明高岭土对这几种离子都是典型的单分子层吸附;Pb2+,Cd2+,Ni2+,Cu2+离子解吸量大小顺序为:Pb2+＜Ni2+＜Cu2+＜Cd2+.     

非活性马尾藻对水中Cd~(2+)和Ni~(2+)的生物吸附及脱附研究

【目的】以马尾藻粉为生物吸附剂,研究其在静态实验中对Cd2+和Ni 2+的吸附及脱附能力,并对吸附速度、动力学、重金属选择性和吸附剂再生等问题进行探讨。【方法】采用单因素法分析pH值、初始浓度、平衡离子类型等条件因素对重金属吸附容量的影响,采用准一级和准二级动力学模型对Cd2+、Ni 2+的吸附数据进行拟合。【结果】Cd2+的最佳吸附条件为pH值4.5、初始浓度500mg/L、平衡离子为NO3ˉ,Ni 2+的最佳吸附条件为pH值3.0、初始浓度900mg/L、平衡离子为Clˉ;Cd2+、Ni 2+的吸附平衡到达时间分别为50min和25min;准二级动力学模型对吸附数据的拟合效果更好,相关系数(R2)均大于0.99;对混合溶液中不同重金属的选择性吸附顺序为Pb2+Ni 2+Cd2+Mn2+;1.0mol/L HCl对Cd2+、Ni 2+的理论洗脱率均可达到99%。【结论】马尾藻粉对Cd2+和Ni 2+的吸附容量大,吸附条件温和,重金属脱附率高,是一种性能良好的生物吸附剂。     

海藻酸分子印迹聚合物的合成及其对锌离子的识别作用

将海藻酸钠与锌(II)配位形成配位聚合物膜,用FT-IR和DRS研究所得到的海藻酸-锌(II)配位聚合物(AA-Zn)的形成机理。将此配位聚合物与戊二醛(GA)进行交联,得到交联印迹聚合物前体,并用FT-IR光谱表征其结构。为了制备对Zn2+离子敏感的分子印迹聚合物(MIP),将前体聚合物浸入0.5 moL/L HCl溶液中48 h并搅拌,以洗脱Zn2+离子得到印迹聚合物(MIP-Zn)。洗脱液用UV-Vis光谱检测并验证,UV-Vis谱图显示Zn(II)的特征吸收峰在240 nm处,表明Zn2+离子已被洗脱。将制得的海藻酸钠-锌(II)印迹膜用于吸附Zn2+离子,结果表明印迹聚合物对Zn2+离子有较强的吸附能力。     

Cu(II)离子印迹聚合物微球制备及其性能

饮用水中的重金属是给水处理面临的主要问题之一。以甲基丙烯酸(MAA)为功能单体,乙二醇二甲基丙烯酸酯(EDGMA)为交联剂,甲苯为溶剂,应用反相微乳液聚合方法,制备了Cu(Ⅱ)离子印迹聚合物微球。运用扫描电子显微镜和红外光谱仪等对该印迹聚合物微球进行表征,表明该聚合物微球外观形貌和内部孔隙清晰分明,对水中的重金属Cu(Ⅱ)离子具有良好的识别和吸附性能。     

新型自组装材料的制备及其对钍的识别研究

以钍(IV)为模板离子,制备了基于硅胶表面修饰的离子印迹聚合物.采用傅立叶变换红外光谱和N2吸附-脱附对其进行了结构表征.通过静态分析和动态分析系统研究了印迹聚合物对钍(IV)的吸附行为及选择性,结果表明该印迹材料对钍(IV)的等温吸附线属于Langmuir吸附模型.与非印迹聚合物相比,离子印迹聚合物对钍(IV)离子有较好的选择识别能力,模板离子钍(IV)相对竞争离子铀(VI)、镧(III)和铈(III)的选择系数分别是50.8,78.3和82.6.并且吸附速率快,10 min即达到吸附平衡,最大吸附容量为56.8 mg/g,可望在分离富集领域获得实际应用.     

Mycobacterium phlei菌对重金属Pb~(2+);Zn~(2+);Ni~(2+);Cu~(2+)的吸附规律

研究了Mycobacteriumphlei菌株分别对水相中重金属离子Pb2+,Zn2+,Ni2+,Cu2+的吸附规律·结果表明,Mycobacteriumphlei菌株对水相中的这四种重金属离子均有一定的吸附作用;吸附过程均在10min内就达到平衡;pH对吸附过程影响较大,在pH=3 0～4 0时,Mycobacteriumphlei菌对这四种金属离子吸附效果最好;温度升高对Pb2+,Ni2+和Cu2+的吸附过程不利,但Mycobacteriumphlei菌对Zn2+的吸附则是一个吸热过程·重金属离子在Mycobacteriumphlei菌上的吸附的选择性大小的顺序为:Pb2+>Zn2+>Cu...     

硅藻土对水相中Pb~(2+)的吸附

研究了吉林长白硅藻土吸附水相中Pb2+的吸附过程,讨论了各试验因素对吸附效果的影响·实验结果表明:吉林长白硅藻土对Pb2+有较好的吸附效果·该吸附过程进行得很快,在5min左右就达到吸附平衡·与酸性条件下的吸附效果相比,pH=6 5时的吸附效果最佳·温度对吸附效果影响不大·吸附过程中吸附剂用量少,对100mL铅离子质量浓度为50mg/L的溶液,0 4g的硅藻土就可以使Pb2+去除率达到98%·经过硅藻土二次吸附后,铅离子去除率接近100%·     

氨基磺酸铵-细菌纤维素对Pb~(2+)的吸附性能及机理

为了提高细菌纤维素(BC)对重金属离子的吸附性能,以细菌纤维素为原料通过化学修饰的方法对其进行改性,制备了新型的重金属离子吸附剂氨基磺酸铵-细菌纤维素(ASBC).同时将制得的ASBC用于吸附重金属Pb2+,考察了其对Pb2+吸附性能,并对吸附机理进行了初步研究.结果表明:pH值是影响氨基磺酸铵-细菌纤维素对Pb2+吸附效果的重要参数,对Pb2+的吸附符合二级反应动力学特征和Langmuir吸附等温方程,并具有良好的线性,说明ASBC对Pb2+是典型的单分子层吸附;静电吸引和螯合作用是吸附的主要机理之一.     

啤酒酵母菌对Pb~(2+) 与Zn~(2+) 的生物吸附规律

研究了啤酒酵母菌体对工业废水中重金属离子Pb2+,Zn2+的生物吸附规律·实验结果表明,啤酒酵母菌体对Pb2+的吸附效果比对Zn2+的吸附效果要好;啤酒酵母菌体对铅离子和锌离子的吸附作用与pH值密切相关,最佳的pH值范围均是4～6·体系pH=4时,啤酒酵母菌对Pb2+的吸附量最大,为98 20mg/g;在pH=5 5时,啤酒酵母菌对Zn2+的吸附量最大,为13.89mg/g·在初始铅、锌离子浓度均为1mmol/L的水溶液中,吸附时间为15min即达到吸附平衡,该吸附过程具有一级动力学反应特征·     

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

正~~