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Science China Mathematics 2002年第2期45卷 233-240页

作者：郑采星刘让苏董科军彭平刘海蓉徐仲榆卢小勇 Department of Physics Hunan University Changsha410082 China Department of Chemistry Hunan University Changsha410082 China Department of Electrical Engineering Hunan University Changsha410082 China

For the first time, a molecular dynamics simulation study has been performed for a liquid metal system consisting of 50000 atoms to deeply investigate the transitions of microstructure configurations during the rapid cooling processes. Especially, the cluster-type index method has been adopted to analyze the transforming and evolving processes of clusters and cluster configurations from liquid metal atoms. It has been found that the bigger cluster configurations in the system are formed by means of connecting some small clusters (they are combined by several smaller clusters), and not taken on the multi-shells configuration accumulated with an atom as the center and the surrounding atoms arranged according to some fixed pattern. With the decrease in temperature, the probability of repetitive appearance for clusters increases largely, which reveals that clusters are indeed possessing a certain relative stability and continuity ( namely hereditary effect). These results will give us an important enlightenment to understand not only the forming mechanisms and microscopic processes of the short-order sections and disorder sparse seiions in amorphous structures but also the freezing processes of liquid metals.

关键词： liquid metals, rapid cooling processes, cluster, computer simulation and visualization.

Variation characteristics of heavy metals and nutrients in the core sediments of Taihu Lake and their pollution history

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Science China Earth Sciences 2006年第Z1期49卷 82-91页

作者： LIU Enfeng SHEN Ji LIU Xingqi ZHU Yuxin WANG Sumin Nanjing Institute of Geography & Limnology Chinese Academy of Sciences Nanjing 210008 China Nanjing Institute of Geography & Limnology Chinese Academy of Sciences Nanjing 210008 China Nanjing Institute of Geography & Limnology Chinese Academy of Sciences Nanjing 210008 China Nanjing Institute of Geography & Limnology Chinese Academy of Sciences Nanjing 210008 China Nanjing Institute of Geography & Limnology Chinese Academy of Sciences Nanjing 210008 China

The sedimentary environment change, trophic evolution and heavy metals pollution history of the northern Taihu Lake in the last 100 years are studied according to the sedimentary geochemical proxies of the core sediments, such as grain size, nutrients, heavy metals, diatom, etc. The nutrients in the sediments depended mainly on the lake internal circulation and the heavy metals were from natural geogenic sources before the 1920s, which were not influenced by human activities generally, and grain size was one of the key factors influencing heavy metals content in the *** alternation of manner and strength of human activities in Taihu Lake catchment before and after the 1920s made the lake sediments coarser, and hence heavy metals and TP content decreased contrasted with that before the 1920s. TP content in sediments and water increased from the 1950s to late 1970s due to anthropogenic pollutants discharge, and the lake belonging to mesotrophic *** and TOC content and C/N ratio increased due to the increasing external pollutants into Taihu Lake by human activities, TP content also increased obviously in water and sediments, and the diatom association was dominated by eutrophic species since the late 1970s, indicating the eutrophication state of Taihu Lake in this period. Meanwhile the increasing in heavy metals content, such as Cu, Mn,Ni, Pb and Zn, and their proportion of valid fractions in the sediments indicates that they all result from human pollutants since the late 1970s. The heavy metals in the surface sediments have certain potential biological toxicity due to the higher SEM/AVS ratio.

关键词： sediments, heavy metals, nutrients, human activities, pollution history, Taihu Lake.

Using Atomic Microstates and Atomic Number Parity in Support of Lutetium and Lawrencium Classification as Transition metals

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Journal of Chemistry and Chemical Engineering 2018年第3期12卷 92-95页

作者： Valery Tsimmerman Brookeville Maryland 20833 USA

Unlike other groups of elements, Group 3 constituency remains unsettled. This article argues that ground level microstates and atomic number parity suggest Sc-Y-Lu-Lr Group 3 membership.

关键词： Transition metals, inner transition elements lawrencium placement, rare earth metals, group 3 constituents, ground level atomic microstates, atomic number parity f-block.

Relationship between fracturing nominal stress and porosity for metal foams under biaxial tension

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Science China(Technological Sciences) 2003年第5期46卷 546-550页

作者： LIU Peisheng (刘培生) The Key Laboratory of Beam Technology and Material Modification of Ministry of Education & Department of Materials Science and Engineering Beijing Normal University Beijing 100875 China

The relationship between two fracturing nominal stresses and porosity has been put forward for metal foams under biaxial tensile loading, and its mathematical formula is proved to be quite practical with the relative ...

关键词： metal foams, foamed metals, porous metals, porous materials.

Determination of the heavy metal content of Entoban herbal medicinal product

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Journal of Chinese Pharmaceutical Sciences 2015年第11期24卷 764-769页

作者： Sadia Shakeel Zeeshan Ahmed Sheikh Khan Usmanghani Nadeem Khalid Zafar Ali Somia Gul Safila Naveed Faculty of Pharmacy Dow University of Health Sciences Herbion Pakistan (Pvt.) Ltd. Faculty of Pharmacy Jinnah University for Women Karachi.

The levels of As, Cd, Pb and Hg were investigated in the medicinal herbal syrup Entoban, which is widely used in the management of non-specific diarrhea and acute intestinal infections of various etiologies. The ingredients in Entoban syrup include 6 potent herbal drugs: Aegle marmelose, Berberis aristata, Butea frondosa, Holarrhena antidysenterica, Myrtus communis, and Quercus infectoria. Entoban medicinal plant syrup was analyzed for As, Cd, Pb and Hg by flame atomic absorption spectroscopy(FAAS). Contents of heavy metals in the examined samples were in the range: As(0.074–10.0 ppm); Cd(0.020–0.3 ppm); Pb(0.00–10.0 ppm) and Hg(0.00–1.0 ppm). Results were compared with permissible limit acceptability intake(AHPA). According to determined amounts of heavy metals, the investigated Entoban syrup samples were validated and considered safe for human consumption.

关键词： Heavy metals, Flame atomic absorption spectroscopy, Medicinal plants, Entoban syrup

Metal concentrations and mycorrhizal status of plants colonizing copper mine tailings: potential for revegetation

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Science China(Life Sciences) 2005年第Z1期48卷 156-164页

作者： CHRISTIE Peter Department of Agricultural and Environmental Science The Queen's University of Belfast Newforge Lane Belfast BT9 5PX Northern Ireland UK

A field survey of metal concentrations and mycorrhizal status of plants growing on copper mine tailings was conducted in Anhui Province, China. Available phosphorus and organic matter in the tailings were very low. High concentrations of Pb, Zn, As and Cd as well as Cu were observed on some sites. The dominant plants growing on mine tailings belonged to the families Gramineae and Compositae, and the most widely distributed plant species were Imperata cylin-drica, Cynodon dactylon and Paspalum distichum. Coreopsis drummondii also grew well on the arid sites but not on wet sites. Very low or zero arbuscular mycorrhizal (AM) fungal colonization was observed in most of the plants, but extensive mycorrhizal colonization was recorded in the roots of C. drummondii and C. dactylon. Metal concentrations in plant tissues indicated that /. cylindrica and P. distichum utilized avoidance mechanisms to survive at high metal concentrations. The investigation suggests that remediation and revegetation of heavy metal contaminated sites might be facilitated by selection of tolerant plant species. Isolation of tolerant AM fungi may also be warranted.

关键词： phytoremediation, revegetation, heavy metals, copper mine tailings, arbuscular mycorrhiza.

Rare earth market analysis in May 2017

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China Rare Earth Information 2017年第6期23卷 4-6页

Prices of rare earth products continued to raise in May, especially price of europium oxide, up 31.05% year-on-year. Rare earth market kept rebounding from Jan. to May. The third round of national stockpiling ended on May 27. Total bidding amount reached over 3,000 tons. China Minmetals, Baogang Group, Chalco, Ganzhou Rare Earths, Rising Nonferrous metals, Xiamen Tungsten and CNMC participated in the bidding. Prices of mainstream products were higher than the previous round. For instance, bidding price of europium oxide increased from the previous 500,000 yuan/ton to 570,000 yuan/ton this time, up 14%.

关键词： Ganzhou Rare Earths, Rising Nonferrous metals, Xiamen