重金属对蛇鮈的急性毒性研究

本试验采用静水生物测试法,以蛇鮈(Saurogobio dabryi)为受试生物,以致死率为指标研究了不同质量浓度的重金属铜和锌对蛇鮈幼鱼的急性毒性,结果表明,铜、锌对蛇鮈的24、48、72、96小时LC50分别为0.91mg/L、0.69mg/L、0.56mg/L、0.49mg/L和39.63mg/L、36.06mg/L、32.43mg/L、28.77mg/L,安全质量浓度分别为0.12mg/L和8.96mg/L。铜对蛇鮈为高毒物质,锌对蛇鮈为低毒物质,蛇鮈对铜的耐受性低于对锌的耐受性。     

用壳聚糖絮凝剂处理含镉(Ⅱ)废水

报道了用脱乙酰基壳聚糖为絮凝剂,在电解质Na2SO4的作用下絮凝除镉的方法·考察了酸度、离子浓度、壳聚糖用量对去除率的影响·当水样含镉质量浓度不大于40mg/L,pH=8～9和壳聚糖的含量为1%时,镉的去除率达到9995%以上·在同样的条件下处理冶炼厂的含镉废水,除镉率达到997%以上,其他金属离子铜、锌和铅的残余质量浓度分别为0053,058,001mg/L,低于国家排放标准·还探讨了壳聚糖絮凝除镉机理     

锌对鲫鱼的急性毒性及安全浓度评价

以鲫鱼为受试生物,采用静水法生物测试,以致死率为指标研究了重金属锌对鲫鱼的急性毒性。所得24h、48h、72h和96h的半致死浓度为40.631 mg/L,39.234 mg/L,38.449 mg/L,37.406 mg/L,安全质量浓度为3.7406 mg/L。试验结果表明:鲫鱼对重金属锌的耐受性较高。锌对鲫鱼为低毒物质,其安全浓度远高于标准。LC50与时间的关系密切,随着时间的推移,LC50逐渐变小。同时,还表明锌的致毒过程较快,鲫鱼在48h内即出现大量死亡。     

敌百虫对九孔鲍稚鲍和真猛水蚤的毒性作用

不同温度下 ,敌百虫对稚鲍的毒性作用不同 ,在水温 2 1～ 2 2℃下 ,2 4h、 4 8h、72h、96h的半致死浓度分别为 182mg/L、 4 6mg/L、10 6mg/L ,6 6mg/L ,安全浓度为 4 6mg/L ;水温 2 6～ 2 7℃ ,在相同时间内的半致死浓度分别降至 12 9mg/L、 11 1mg/L、 8 2 5mg/L和5 1mg/L ,安全浓度为 1 11mg/L ;敌百虫对真猛水蚤的毒性也是随着水温升高而增强 ,水温2 1～ 2 2℃ ,2 4h、 4 8h、 72h的半致死浓度分别为 2 7× 10 - 1mg/L、 3 5× 10 - 2 mg/L、 2 0×10 - 2 mg/L ,安全浓度为 3 5× 10 - 2 mg/L ;当水温升至 2 6～ 2 7℃时 ,半致死浓度分别为 8 3× 10 - 2mg/L、8 3× 10 - 3mg/L、3 6× 10 - 3mg/L ,安全浓度为 8 3× 10 - 4mg/L 敌百虫对稚鲍的亚急性作用结果是 :在 0 4～ 2 0mg/L下生活 2 0d ,稚鲍的壳长、体重、摄食及存活率随其浓度的增大而降低 本文对九孔鲍工厂化育苗中如何正确使用敌百虫防治底栖桡足类提供了科学依据     

镉对鲫鱼胃肠道嗜银细胞密度的影响

以鲫鱼为研究对象,采用静水染毒法,设对照组和试验组(镉质量浓度0.05 mg/L,0.5 mg/L,5 mg/L)静养10 d,硝酸银染色方法显示鲫鱼胃肠道嗜银细胞,探讨了镉对鲫鱼胃肠道嗜银细胞密度的影响。结果表明,镉对鲫鱼前肠和中肠嗜银细胞数目有明显影响,表现在0.05 mg/L,0.5 mg/L浓度时前肠和中肠嗜银细胞数目明显增加,5 mg/L浓度时则减少;镉对鲫鱼后肠嗜银细胞的影响较小。     

环境友好产品--过氧化钙的合成及其应用

通过加入新型稳定剂磷酸铵,研究了常温水相中合成过氧化钙的新工艺.讨论了原料配比、浓度、温度、时间、稳定剂加入量等因素对过氧化钙产率和纯度的影响,在最佳条件下合成的CaO2纯度大于65%.采用CaO2产品处理含铜、镉、铅、锌离子的工业废水,通过原子吸收分光光度计测定处理前后废水中铜、镉、铅、锌离子的浓度.结果表明,在室温下,过氧化钙用量与重金属离子摩尔比为2∶1时,处理60 min,处理过程不调节pH的条件下,含铜54.12 mg/L、镉36.58 mg/L、铅22.74 mg/L、锌30.10 mg/L的废水经一次处理后,铜、镉、铅、锌去除率均达到99.5%以上,且铜、镉、铅、锌浓度均达到国家一级水排放标准.     

鲫鱼体内重金属的分布和积累规律研究

对采自嘉陵江重庆段的鲫鱼的鱼鳞、肉和内脏中的汞、铅、砷、铜、铬和锌等的含量进行了监测 ,并对其分布和积累规律进行了研究。结果表明 :汞、锌在鲫鱼体内的分布为鱼鳞大于内脏大于鱼肉 ;砷的分布为鱼鳞大于鱼肉大于内脏 ;铜在鱼内脏中含量较高 ;铅和铬的分布为内脏大于鱼鳞大于鱼肉。不同重量级间及各组织间的含量差异显著。积累含量C与鱼重G的关系分别为 :砷在鱼鳞和内脏中是C =2 .32 3× 10 -3 G1.3 60 和C =8.810× 10 -3 G0 .695 ;汞和铜的C与G间的这种关系不明显 ;铅、铬和锌的C与G的关系是C =0 .0 385G0 .2 12 ,C =1.2 88× 10 -4 G1.695 和C =0 .12 1G0 .2 5 0 。     

城镇小型污水处理厂对重金属的去除

为探讨不同的污水处理工艺对重金属的去除效果,通过对浙中地区SBR,CAST,A/O,A2/O和氧化沟5个典型的城镇小型污水处理工艺进行调查,利用微波等离子体原子发射光谱仪对污水处理厂进出水中铬、镍、锌、镉、铅、铜6种重金属进行了测定与分析.结果表明:1)各污水厂重金属进水质量浓度为10-1～103μg/L; 2) CAST处理工艺对6种重金属去除效果相对其他几种工艺较好; 3) CAST,SBR与氧化沟工艺对锌的去除效果居前,分别为74. 26%,71. 00%,66. 22%,CAST工艺对铜的去除效果达74. 56%,SBR工艺对镍的去除率为67. 87%,A/O工艺对铬的去除率为72. 10%; 4)不同污水处理工艺对重金属的去除效果各不一样.     

铜、锌离子抗性菌筛选及重金属作用下富集特性研究

从湖南临乡桃林矿区土壤中分离到一株高抗铜、锌菌株,经26S rRNA D1/D2鉴定为Aspergillus aculeatus.该菌株单抗铜400 mg/L、锌800 mg/L.优化条件下:30 ℃,pH值5.0,起始离子浓度50 mg/L,摇床转速120 r/min,培养时间120 h,菌体对铜、锌离子的吸附率为54%和60%.铜、锌离子浓度50 mg/L时,菌体内谷胱甘肽含量达到最大值分别为0.98和0.88 mg/g;而正常菌体内只有0.04 mg/g.可初步认为谷胱甘肽的增加缓解了铜、锌离子对Aspergillus aculeatus的氧化损伤.     

汾河中上游农田土壤重金属含量特征及来源解析

为了解山西汾河中上游农田土壤重金属污染状况及其污染来源,对其重金属含量进行了研究,并通过相关分析法、聚类分析法、主成分分析法对汞、镉污染进行源解析。结果表明:所有点位汞、砷、铜、锌、镍、铅、镉、铬平均质量分数分别为0.14 mg/kg、9.13 mg/kg、14.50 mg/kg、53.28 mg/kg、20.56 mg/kg、14.56 mg/kg、0.14 mg/kg、37.83 mg/kg,汞、镉2种重金属污染最严重,污染程度排序为:汞镉砷铅锌铬镍铜;S29点位均为最高值,最低值均在S1点位;汞、镉污染主要为流域煤企和化工排废及引黄汇口上游水质影响。     

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