山东省胃癌高低发病区人发中的微量元素分析

用ＰＩＸＥ技术分析人发中微量元素，给出了山东省胃癌高发区栖霞县和低发区苍山县高发病年龄组（５５～６５岁）健康人发中的微量元素谱．测量数据的统计结果显示，栖霞县人发中砷、铬、铁和钴的含量明显高于苍山县，而硒则明显低于苍山县     

山东省胃癌高低发病区人发中的微量元素分析

用ＰＩＸＥ技术分析人发中微量元素，给出了山东省胃癌高发区栖霞县和低发区苍山县高发病年龄组（５５￣６５岁）健康人发中的微量元素谱，测量数据的统计结果显示，栖霞县人发中砷、铬、铁和钴的含量明显高于苍山县，而硒则明显低于苍山县。     

硒对茶树镉毒害的缓解作用研究

【目的】通过溶液培养试验,探讨硒(Se)对镉(Cd)胁迫下茶树生长和生理特性的影响,为保障茶叶饮用安全和综合开发利用提供参考。【方法】以种植于陕西汉中地区的‘龙井43’茶树为试验材料,采用营养液培养方法,分别进行镉和硒处理试验,包括7个处理,分别为Cd 10 mg/L、Se 0.5 mg/L、Se 1.5 mg/L、Se 3.0 mg/L、Se 0.5 mg/L+Cd 10.0 mg/L、Se 1.5 mg/L +Cd 10.0 mg/L、Se 3.0 mg/L +Cd 10.0 mg/L。测定了不同质量浓度硒处理缓解茶树叶片镉毒害的生理响应,以及茶树叶生物量,茶树叶硒和镉的含量。【结果】与未施加镉和硒的对照相比,单一施镉处理使得茶树叶片的光合色素含量、过氧化氢酶(CAT)、抗坏血酸过氧化物酸(APX)、谷胱甘肽过氧化物酶(GPX)活性,以及生物量和可溶性糖、可溶性蛋白含量受到明显抑制,而丙二醛(MDA)和过氧化氢(H₂O₂)含量、渗透调节物质脯胺酸含量明显增加。单一施硒处理条件下,与单一施镉处理对比,上述指标均不同程度得到显著改善,其中1.5 mg/L硒处理下茶树叶片的各项指标改善程度最高。与单一施镉处理相比,在镉和硒的复合处理下,随着硒含量提高,上述各项指标均不同程度得到改善,以Se 1.5 mg/L +Cd 10.0 mg/L复合处理下的各项指标改善程度最高。硒的施加有助于缓解茶树叶片镉的积累。【结论】施加适量的硒在一定程度上可以增加茶树叶片镉诱导产生的抗氧化酶CAT、APX和GPX活性,降低质膜过氧化产物MDA和H₂O₂含量积累,缓解镉对茶树叶片的毒害,并降低对镉的积累。     

北京城区麻雀体内污染物的研究

通过比较重工业区和对照区麻雀（Passer montanus)的肝脏、胸肌和初级飞羽中砷（As)、硒（Se)以及重金属汞（Hg)、铬（Cr)、镉（Cd)、铅（Pb）、锰（Mn)、铜（Cu）的质量分数,探讨了将麻雀作为环境指示物种的可行性。分析结果表明,重工业区麻雀体内污染物的质量分数明显高于对照区;成鸟体内的Hg,Se,Cd,Pb,Cu明显高于幼鸟;重工业区麻雀羽毛中Se,Cd,Pb,Mn和Cu的质量分数显著高于对照区;对比羽毛和其他组织中各元素的聚集量,发现羽毛中Cd,Mn,Cu的质量分数和肝脏、肌肉中的呈显著性正相关,这几种元素在羽毛中的积累和在其他组织中的积累有线性关系。这显示采用麻雀羽毛监测环境中某些元素的污染是可行的,麻雀能够作为城市环境的指示物种。     

水果中矿物元素含量分析与评价

利用微波消解-石墨炉原子吸收光谱法,分析了本地区市售20种水果中铜(Cu)、镉(Cd)、铅(Pb)、锌(Zn)、硒(Se)元素的含量,并进行了初步风险评价.结果表明:红富士苹果中Cd含量最高,平均含量为4.548μg/kg;山竹中Cu含量最高,平均含量为409.150μg/kg;红富士苹果中Pb含量最高,平均含量为18.340μg/kg;桃子中Zn含量最高,平均含量为693.400μg/kg;橙子中Se含量最高,平均含量为16.080μg/kg,但均远低于2011年颁布的国家限量标准.不同人群经水果摄入Cu、Cd、Pb和Zn的风险较低,但经水果摄入Se有一定的风险.本结论可为食品安全监控和合理饮食研究提供理论参考.     

贵州富锌硒茶产区地质环境条件与土壤元素地球化学特征

通过对贵州不同区域典型茶园进行野外调查,在每个茶叶主产区选择代表性的茶园进行土壤剖面样品采集,探讨贵州富锌硒茶产区地质环境条件与土壤元素地球化学特征.结果表明:贵州茶叶主产区成土母岩及土壤中主要元素含量水平存在明显的区域差异,富锌硒茶产区成土母岩中S、Ca、Fe、P、Mo含量均明显高于非富锌硒茶产区,其次是Zn、Se、...     

阴极溶出伏安法测定痕量硒

据有关资料报道,人体内可以测定出几十种微量元素,其中硒(Se)是人体所必需的微量元素之一,与人体健康关系十分密切。 硒与维生素E相互作用防止肌肉的营养不良;硒能保护组织不被氧递降分解;特别是硒能逆转危害性大的镉(Cd)对人体所产生的不良影响。现已确定人体内镉的浓度与心脏病有着密切联系,而且患某些癌的病人体内镉的含量明显高于正常健康的人,然而硒却能抵消镉的不良影响,不仅如此,硒还是其它重金属毒性的特殊解毒剂。     

赣东北万年地区富锗土壤与农作物地球化学特征及其意义

锗元素在工业和医疗领域都具有良好的应用潜力,所以富锗土壤的开发具有很大意义。为适应国民经济发展的新需求,紧密配合鄱阳湖生态经济区建设,研究上饶市万年县部分地区的土壤与农作物中锗的含量并对研究区开展地球化学评估。结果表明:研究区内水稻样品锗元素的含量变化范围在0.003～0.010 mg/kg之间,平均含量为0.005 mg/kg;水稻根系土壤中锗含量较高,变化范围1.61～2.74 mg/kg,全锗的平均含量为1.98 mg/kg,稍小于该地表层土壤背景值。同时研究区土壤环境质量总体优良,区内I类及II类土壤分布面积约占研究区总面积的88.68%,且齐埠乡地区土壤环境质量达到优等。水稻中Ge元素与土壤中的Hg、Ge的含量呈极低正相关关系,且与土壤的p H呈低度正相关关系;水稻中Ge元素与土壤中As、Cd、Cr、Cu、Pb、Ni、Zn、Se、有机质、CEC含量呈负相关关系,其中Cr、Cu、Ni、Se、有机质、CEC与水稻Ge呈现明显的负相关关系。水稻中,Se、Zn、Cd、Cu、Hg等元素为高富集元素; Ni为中富集元素; Ge、As、Cr、Pb为低富集元素,即元素的含量与水稻自身的吸收富...     

弥河流域土壤中钴、钼、硒、锌空间分布及来源分析

为研究弥河流域表层土壤中钴(Co)、钼(Mo)、硒(Se)、锌(Zn)的空间分布及其来源,在弥河流域不同用地类型表层土壤中采集48个样品,测定四种微量元素含量及其他土壤理化指标,并采用空间插值和正定矩阵因子分析(positive matrix factorization, PMF)等数理方法进行了数据分析。结果显示,研究区内Co、Mo、Se、Zn均存在不同程度的富集现象,其中在耕地中富集程度最高。Co和Mo的高浓度区主要分布在临朐-青州-昌乐三县交界地带,Se的高浓度区主要分布在研究区西部,Zn的高浓度区主要分布在研究区西南部。土壤中Co含量主要受铁锰氧化物和土壤质地影响,Mo主要受铁锰氧化物影响,Se主要受N、P、有机质影响,Zn主要受N、P、有机质和土壤质地影响。PMF模型源解析表明研究区内Co、Mo、Se、Zn的主要来源为自然源、农业源和交通-工业混合源,所占比例分别为44.6%、35.7%和19.7%,其中Co、Se主要来源于自然源(48.7%、51.3%),Mo、Zn则自然源、农业源和交通-工业混合源均衡。     

大花君子兰(Clivia miniata RegeI)体内的微量元素

用火焰发射原子吸收分光光度计和石墨炉原子吸收分光光度计分析了君子兰叶片、花瓣、花粉、果实外皮和根的铜、锌、铁、锰、镁、铅、铬、钴、镉、镍、硒十一种元素的含量。发现花瓣中镁、铁、锌的含量都此较高。铜、铅、铬、镉、钴在君子兰体内含量较低。硒含量很高,甚至高于吉林人参。甘肃岩昌黄芪和蒙古黄芪的含硒量。     

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.     

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