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“重击”不但成为有效的得分手段，而且效果显著可直接获优势胜利。散手运动实践表明，灵活、巧妙地运用重拳或横踢腿击头，最易达到“重击”的目的。本文举例说明在主动进攻及防守反击中实施重击的技巧。 相似文献
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以宿州煤矿区为例,通过现场采样和室内试验测定,探讨了土壤-豆类作物系统中重金属元素Cu、Pb、Zn、Cr、Cd和Mn的含量特征及富集状况,并利用潜在生态风险指数和健康风险模型对土壤及农作物的安全风险水平进行了评估,结果表明:矿区农田土壤中Cd严重超标,导致土壤潜在生态风险达到强等级程度;豆类作物对土壤中各重金属元素的富集系数依次为ZnCuCdMnPbCr,大豆与绿豆相比,更易于吸收Cu、Pb、Cd和Mn,而对Zn和Cr的富集能力稍弱;两种日均摄食量情境下,豆类作物的重金属致癌危害风险以Cr最高,风险值超出ICRP和USEPA的最大可接受风险水平,而非致癌危害风险以Cu最高,风险值高于HCEPD的可忽略风险水平。 相似文献
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文章以文献资料法,数理统计法和综合分析为主要研究方法,围绕运动训练能否导致骨骼肌纤维类型转这一有争议话题,阐述目前对此问题的两种不同观点及其实验证据,以及运动训练对骨骼肌纤维产生的影响,以使读者对当前纤维类型与遗传和运动训练关系研究状况有所了解,并具同时阐述了自己的一些观点。 相似文献
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婺江柱样沉积物的磁学特征及其与重金属污染的相关分析 总被引：1，自引：0，他引：1
通过对婺江江心洲伍佰滩柱样沉积物(76cm)进行多项磁学参数和重金属含量的测定,得到磁性物质和重金属的垂直分布情况。运用SPSS软件对所得数据作主成分分析,分析表明磁学指标χARM/SIRM和χfd%与Fe、Al、Pb、Ga、V、Ce、Cr、Ni、Cu等重金属含量有较强的相关关系,反映了细晶粒亚铁磁性矿物对重金属的吸附作用。建立了利用磁学参数χARM/SIRM和χfd%推断污染较严重的几种重金属含量的线性回归模型。本研究表明利用磁学参数来快速推断河流沉积物的重金属污染状况是可行的。 相似文献
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贵州省磷石膏渣对乌江汞排放的评估与环保对策 总被引：1，自引：0，他引：1
常近时 《毕节师范高等专科学校学报》2014,(8):62-67
在联合国环境规划署（UNEP）制定的国际《水俣公约》正式生效之前,本文对我国采用传统湿法工艺生产磷酸的废渣磷石膏对水环境污染的形势做了分析;实测了贵州磷石膏悬浊液中重金属含量,发现汞的含量很高。估算了贵州两大磷肥企业磷石膏渣堆向乌江排入悬浊液总量和汞与其它毒重金属的年排量。对全国汞排量最多的贵州省做了汞排结构分析,指出乌江干流水库遭磷石膏污染的严重危害,提出若干相应的环保对策。 相似文献
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Mycorrhizoremediation an enhanced form of phytoremediation 总被引：2，自引：0，他引：2
Khan AG 《Journal of Zhejiang University. Science. B》2006,7(7):503-514
Study of plant roots and the diversity of soil micro biota, such as bacteria, fungi and microfauna associated with them, is important for understanding the ecological complexities between diverse plants, microbes, soil and climates and their role in phytoremediation of contaminated soils. The arbuscular mycorrhizal fungi （AMF） are universal and ubiquitous rhizosphere mi- croflora forming symbiosis with plant roots and acting as biofertilizers, bioprotactants, and biodegraders. In addition to AMF, soils also contain various antagonistic and beneficial bacteria such as root pathogens, plant growth promoting rhizobacteria including free-living and symbiotic N-fixers, and mycorrhiza helping bacteria. Their potential role in phytoremediation of heavy metal （HM） contaminated soils and water is becoming evident although there is need to completely understand the ecological complexities of the plant-microbe-soil interactions and their better exploitation as consortia in remediation strategies employed for contaminated soils. These multitrophic root microbial associations deserve multi-disciplinary investigations using molecular, biochemical, and physiological techniques. Ecosystem restoration of heavy metal contaminated soils practices need to incorporate microbial biotechnology research and development. This review highlights the ecological complexity and diversity of plant-microbe-soil combinations, particularly AM and provides an overview on the recent developments in this area. It also discusses the role AMF play in phytorestoration of HM contaminated soils, i.e. mycorrhizoremediation. 相似文献
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《线性代数》是高等院校一门重要的公共基础课,内容具有很强的抽象性,逻辑性,内在联系性。本文研究了自考课程《线性代数（经管类）》助学中要注意的教学重难点以及教学内容的内在联系,旨在帮助自考学生掌握线性代数课程,提高学习效率和自考考试成绩。 相似文献
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XU Dong-mei CHEN Bo LIU Wen-li LIU Guang-shen LIU Wei-ping 《浙江大学学报(A卷英文版)》2007,8(7):1157-1163
Comparative study on the activity and kinectic properties of acid phosphatase (ACPase) of three soils amended with Hg and Cu at constant temperature and humidity was carried out. The results indicated that the inhibition on ACPase of the three sample soils by Hg and Cu varied with the content of soil organic matter and pH, where, Soil 1 was the most seriously contami- nated due to its lowest content of organic matter and the lowest pH among three samples, Soil 2 took the second place, and Soil 3 was the least contaminated. Except Soil 3, the activity of soil ACPase tended to increase along with the contact time under the same type and the same concentration of heavy metal. In particular the Vmax values of ACPase in all three samples decreased with increasing Hg and Cu concentration, whereas the Km values were affected weakly. According to the change of Vmax and Km values, Cu and Hg had the same inhibition effect on soil ACPase. Both of them may be a type of compound of non-competitive and anti-competitive inhibition. Statistic analyses indicated that activities of soil ACPase and Vmax values could serve as bioindicator to partially denote the heavy metal Hg and Cu contamination degree. 相似文献
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INTRODUCTION Regulation, handling and bioremediation of hazardous materials require an assessment of the risk to some living species other than human being, or assessment of hazard to the entire ecosystem. As- sessment endpoints are values of the ecosystem that are to be protected and are identified early in the analysis. Such endpoints may include life cycle stages of a species and reproductive or growth patterns. Ecosystem risk assessment is at its dawn with this area of environment sci… 相似文献