Zn~(2+)、Mn~(7+)对刺参幼参的急性毒性及富集作用研究

在静水条件下,研究了Zn2+、Mn7+两种重金属离子对刺参幼参行为及其存活状况的影响,并分析了其在幼参体内的富集状况。结果表明:Zn2+、Mn7+单独处理时,幼参在Zn2+浓度低于0.4 mg/L或Mn7+浓度低于0.5 mg/L条件下暴露96 h后死亡率均为0.0%,表明在此对应浓度范围内两种金属离子均无明显的急性毒性作用;随浓度和暴露时间增加,幼参死亡率明显升高,其附壁率呈降低趋势。Zn2+对幼参的24、48、72 h的半致死浓度LC50分别为49.70、1.35、0.82 mg/L,安全浓度(SC)为0.14 mg/L;Mn7+对幼参的48、72、96 h的半致死浓度LC50分别为31.61、4.24、3.13 mg/L,SC为3.16 mg/L。因此,Zn2+对幼参的急性毒性作用强于Mn7+。随着水体中Zn2+与Mn7+浓度的增加,幼参体内重金属元素含量和累积速率总体呈升高趋势,而富集系数呈降低趋势,Zn2+的富集作用强于Mn7+。     

Se(Ⅳ)对钝顶和极大螺旋藻生长的影响

采用藻类生长动力学函数和藻类测试化学品毒性的标准方法,分别研究了高、低质量浓度Se（Ⅳ）对钝顶（S．platensis）和极大（S．maxima）螺旋藻生长的影响,结果表明：低质量浓度组中,Se（Ⅳ）的质量浓度低于16mg／L时对钝顶螺旋藻前4d的生长影响差异无显著性意义,但当质量浓度为32mg／L时出现明显的抑制作用;而低质量浓度范围内,即质量浓度低于32mg／L的Se（Ⅳ）在前4d对极大螺旋藻的生长的影响不明显．高质量浓度组中,当质量浓度高于560mg／L时,钝顶螺旋藻的生长被完全抑制;硒对极大螺旋藻的最低完全抑制质量浓度为600mg/L.     

不同地区茶叶中微量元素的测定

目的：对云南普洱茶、贵州苦丁茶、河北茉莉花茶中的锌（Zn）、铁（Fe）、铜（cu）、盌t（Mn）4种微量元素进行测定。方法：将样品用干法进行消解,并利用火焰原子吸收光谱法测定3种茶叶中Zn、Fe、Cu、Mn4种微量元素的含量。结果：Zn、Fe、Cu、Mn4种微量元素在3个地区茶叶中含量分别是云南普洱茶：43．43ug／g、57．28Ixg／g、33．14txg／g、135．67txg／g;贵州苦丁茶：19．91ug／g、32．98ug／g、9．74ug／g、77．08ug／g;河北茉莉花茶：36．09ug／g、84．37ug／g、28．52ug／g、220．08ug／g。结论：3种茶叶中均含有丰富的微量元素,不同地区茶叶中微量元素含量有一定差异。     

极大螺旋藻(Spirulina maxima)对六种重金属离子的生物吸附作用

研究了极大螺旋藻(Spirulina maxima)对Ag 、Cu2 、Mn2 、Ni2 、Pb2 和Zn2 等六种重金属离子的吸附作用.结果表明在pH5.5,吸附时间2h,重金属离子浓度为50mg/l的条件下,极大螺旋藻对六种重金属离子均有较强的吸附作用,其中对Ag 的吸附作用最强,吸附率为92.87%;对Ni2 的吸附作用最弱,吸附率为40.70%.极大螺旋藻对这6种离子的吸附能力依次为Ag ＞Pb2 ＞Zn2 ＞Cu2 ＞Mn2 ＞Ni2 .     

Cu、Zn、Mn对油菜种子萌发及幼苗生长的影响

采用水培实验研究了重金属元素Cu、Zn、Mn对油菜种子萌发、幼苗生长以及叶绿素含量的影响.结果表明低质量浓度≤50mg/L的Cu、Zn、Mn水溶液能促进油菜种子萌发、幼苗生长以及叶绿素的形成,而高质量浓度≥150mg/L的Cu、Zn、Mn水溶液对油菜生长有抑制作用.     

和静县耕地土壤微量元素缺素状况及应对措施

1和敖县耕地土壤微量元素缺素状况 根据新疆第二次土壤普查资料，和静县耕地剖面耕作层对B、Fe、Cu、Mn、Zn样品分析结果，微量元素中B、Fe、Cu三种元素都很丰富，而Mn和Zn两种元素普遍都缺。依据新疆土壤分级标准：有效Zn〈0．5mg／kg为极缺，0．5—1．0mg／kg为缺，1-2mg／kg为适量，〉2mg／kg为丰富；     

芦柑果皮和果肉中微量元素比较

南方富产大量的芦柑,实验结果表明:芦柑果肉和果皮中富含对人体有益的微量元素Cu、Fe、Mn、Se、Zn、K、Ca和Mg.其中Cu、Fe、Mn、Se和Zn等的元素含量范围在3.62～30.74μg.g-1,Mg、Ca和K三元素的含量范围在9.46～34.40mg·g-1.微量元素含量大小顺序为:K>Ca>Mg>Se>Mn>Fe>Zn>Cu.比较果皮和果肉中元素含量,Cu、Fe和Mn的含量果皮低于果肉,Se、Zn、K、Ca和Mg等元素的含量超过果肉.Se、Zn和Mg的含量果皮是果肉的1.12～1.17倍,K和Ca的含量果皮尤其高,分别是果肉的2.81和5.55倍.通过水泡制芦柑皮,得出元素浸提最佳温度为80℃,时间30min.元素浸提率为5.01%～97.70%.K、Ca和Zn浸提率为5%～7%,Se、Mn和Mg浸提率为20%～30%,Cu和Fe浸提率尤其高,分别为95.02%和97.70%.日常饮用水泡制芦柑皮是补充人体所需微量元素的好方法.研究为芦柑皮应用开发提供了科学依据.     

原子吸收光谱法测定不同矿泉水中的微量元素

用原子吸收光谱法对9种不同品牌矿泉水中的10种微量元素进行了测定，结果表明：天然矿泉水含有Cu、Zn、Fe、Mn、Ni、Ca、Mg等多种对人体健康有益的微量元素，其中奥必佳矿泉水Cu含量（0．0326mg／L）、统一矿表水Zn含量（0．4471mg／L）和Mn含量（0．0249mg／L）、农夫山泉矿泉水（Ca：113．09mg／L，Mg：24．27mg／L）和统一矿泉水（Ca：107．82mg,／L，Mg：15．30mg／L）Ca、Mg含量相对较丰富；而不同矿泉水中均合有丰富的Fe和Ni。9个品牌的矿泉水中毒理指标Pb、Cd、Cr含量均较低。与其他几个国家和组织的饮用水标准进行了比较，所分析的矿泉水均符合饮用水水质标准。     

Cu^2＋和Zn^2＋抗性真菌的分离、鉴定及其富集特性

从湖南省岳阳市临湘铜锌尾砂坝士壤内分离、纯化得到1株抗铜和锌的菌株CTB430-1,分析该菌株形态和测定菌株ITS基因序列鉴定菌种,研究不同pH值、金属离子初始浓度和金属离子共存对菌体生长量和富集重金属的影响;分别采用考马斯亮兰法和碘量法测定菌体内可溶性蛋白和还原性谷胱甘肽含量.研究结果表明:鉴定该菌株为Aspergillus flavus,其对Cu2+和Zn2+的最低抑菌质量浓度分别为400和800 mg/L,菌株的生长和富集受溶液pH值、金属离子初始质量浓度和金属离子共存的影响,Cu2+和Zn2+的富集量分别在其质量浓度为200和250 mg/L时达到最大,为30.82和40.37 mg/g;菌体内可溶性蛋白和还原性谷胱甘肽含量发生变化,表明菌株对Zn2+具有较强的适应能力和抗性,还原性谷胱甘肽能缓解Cu2+和Zn2+对CTB430-1的氧化损伤.     

食用蓝藻螺旋藻和葛仙米中金属元素的分析

采用硝酸和高氯酸(4∶1)混合酸消化2种可食用蓝藻螺旋藻和葛仙米,原子吸收光谱法检测螺旋藻和葛仙米中的K、Na、Mg、Ca、Zn、Fe、Cu、Mn、Cr、Pb和Cd共11种金属元素含量。结果表明,2种蓝藻中矿质元素含量均较高,特别是Ca含量高达61 905.132mg·kg~(-1);而有害重金属Cr,Po和Cd含量均远低于国家规定标准,表明这2种食用蓝藻均无重金属富集或污染。本结果显示,螺旋藻和葛仙米是极好的天然富钙营养食品,可作为人体矿质元素和微量元素缺乏症的补给品.     

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.     

An Analysis of Catherine＇s Character——Wuthering Heights

Wuthering Heights, Emily Bronte＇s only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.     

Lower Paleozoic oil relationships within Williston Basin, Canada

The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.     

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.     

Design and analysis of generic LBS application developing platform

Location based services is promising due to its novel working style and contents.A software platform is proposed to provide application programs of typical location based services and support new applications developing efficiently. The analysis shows that this scheme is easy implemented, low cost and adapt to all kinds of mobile nework system.     

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