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植物修复是土壤重金属污染修复的重要手段。为了探明南水北调工程中线水源地土壤污染状况并对其进行修复,本研究以湖北省朝北河和典型钒矿冶炼厂为对象,按季节采集该区域土壤(样本量n = 14)和当地优势陆生植物(样本量n = 113),使用微波消解?电感耦合等离子体质谱(ICP?MS)测定V、Cr、As和Cd重金属含量,根据内梅罗指数法综合评价了土壤污染程度,评估了各种植物对四种重金属的富集能力。结果表明,朝北河采样点中排污口与河水交汇处土壤中重金属Cd含量较高;钒矿冶炼厂原矿堆放区V超标近83倍,Cr、As和Cd重金属超标两倍以上,土壤受到严重污染;其他采样点均受到不同程度的重金属污染。植物重金属富集能力和耐受性评价结果表明,鼠麴草、密叶飞蓬、一年蓬对四种重金属耐受性极强,小蓬草、白茅、少花龙葵、野菊、白车轴草、稗是V、Cr和Cd的超富集植物,蜈蚣草、构树对As的富集能力极强,野艾蒿对Cr和Cd的富集能力较强,丁香蓼和日本毛连菜分别对Cr和V具有较强的耐受性和富集特异性,委陵菜和垂序商陆对Cd具有较强的富集能力和特异性。五种优势植物盆栽实验表明,苎麻在复合金属污染条件下耐受性最强,委陵菜富集能力最强
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This is an admirably concise and clear guide to fundamental concepts in physiology relevant to clinical practice. It covers all the body systems in an accessible style of presentation. Bulleted checklists and boxed information provide an easy overview and summary of the essentials. By concentrating on the core knowledge of physiology, it will serve as a useful revision aid for all doctors striving to achieve postgraduate qualification, and for anyone needing to refresh their knowledge base in the key elements of clinical physiology. The author’s own experience as an examiner at all levels has been distilled here for the benefit of postgraduate trainees and medical and nursing students. Dr Ashis Banerjee is Consultant in Emergency Medicine and serves as Examiner for those undertaking their MB, BS, MRCS and MFAEM examinations
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Data Hazards ◼ Instruction having register R as source follows shortly after instruction having register R as destination ◼ Common condition, don’t want to slow down pipeline Control Hazards ◼ Mispredict conditional branch ⚫ Our design predicts all branches as being taken ⚫ Naïve pipeline executes two extra instructions ◼ Getting return address for ret instruction ⚫ PIPE- executes three extra instructions Making Sure It Really Works ◼ What if multiple special cases happen simultaneously?
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In this lecture, we consider the motion of a 3D rigid body. We shall see that in the general three dimensional case, the angular velocity of the body can change in magnitude as well as in direction, and, as a consequence, the motion is considerably more complicated than that in two dimensions. Rotation About a Fixed Point We consider first the simplified situation in which the 3D body moves in such a way that there is always a point, O, which is fixed. It is clear that, in this case, the path of any point in the rigid body which is at a
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We will start by studying the motion of a particle. We think of particle as a body which has mass, but has negligible dimensions. Treating bodies as particles is, of course, an idealization which involves an approximation. This approximation may be perfectly acceptable in some situations and not adequate in some other cases. For instance, if we want to study the motion of planets it is common to consider each planet as a particle
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Intensive Study As His Name Is, So Is He! Para.1 For her first twenty-four years, she'd been known as Debbie-a name that didn't suit her good looks and elegant manner. \My name has always made me think I should be a cook, she complained. \I just don't feel like a Debbie.\
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Topics to be Discusses Aggregate Demand (AD) Function Aggregate Supply (AS) Function AS-AD Model Price Changes and Determination of Output Price Adjustment Process
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Carbon’s ability to form strong covalent bonds to other carbon atoms is the single property of the carbon atom that — more than any other—accounts for the existence of a field of study called organic chemistry. Carbon’s ability to form as many as four strong bonds to other carbon atoms, and to form strong bonds to hydrogen, oxygen, sulfur, and nitrogen atoms as well
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Compounds were classified as being either aliphatic or aromatic in the latter part of the nineteenth century. To be classified as aliphatic meant then that the chemical behavior of a compound was “fatlike”. To be classified as aromatic meant then that the compound had a low hydrogen/carbon ratio and that it was “fragrant
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1. As an organizing principle for life a. We tend to think of kin as something natural biological or as having some basis beyond culture i. For example, children reuniting with birth parents b. Kinship is actually highly variable and artificial from one culture to the next
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