Optical microscopy, and scanning electron microscopy in conjunction with energy dispersed X-ray spectrometry （SEM-EDX）, have been used to study the minerals and the concentrations of 12 trace elements in the No.14 c...Optical microscopy, and scanning electron microscopy in conjunction with energy dispersed X-ray spectrometry （SEM-EDX）, have been used to study the minerals and the concentrations of 12 trace elements in the No.14 coal from the Huolinhe mine, Inner Mongolia China. The distribution, affinity and removability of the trace elements were studied by float-sink experiments and petrological methods. A high mineral content, dominated by clay minerals, was found in the No.14 coal from the Huolinhe mine. The concentrations of As, Sb and Hg are relatively high compared to the average values for Chinese coals. As, Cr, Hg, Li, Mn, Pb are mainly associated with the minerals while Cd, Co, Ni, Sb, and Se are evenly distributed between the minerals and the organic matter. Be and Ba are mainly distributed in the minerals with a minor proportion in the organic matter. Most elements have a low organic affinity, although Sb, Se, Co, Cd, Ni are closely integrated with the organic matter. High theoretical removabilities are indicated for most trace elements. So it may be possible to lower the concentrations of trace elements during coal preparation.展开更多
In his first speech on February 17 to a joint session of Congress, US President Bill Clinton outlined his wision of smaller deficits through higher income taxes on the wealthy, increased energy taxes and selected spen...In his first speech on February 17 to a joint session of Congress, US President Bill Clinton outlined his wision of smaller deficits through higher income taxes on the wealthy, increased energy taxes and selected spending cuts including a one-year freeze on federal pay. US Secretary of State Warren Christopher arrived in Cairo on February 18 to start his six nation Middle East tour which will also take him to Jordan, Syria, Saudi Arahia, Kuwait, Israel and Lebanon.展开更多
China announced on April 16 its decision to send military observers and engineers to join UN transitional authorities in Cambodia. The contingent left Beijing on the same day. On April 21, Peruvian President Alberto F...China announced on April 16 its decision to send military observers and engineers to join UN transitional authorities in Cambodia. The contingent left Beijing on the same day. On April 21, Peruvian President Alberto Fujimori announced a 12-month plan to return Peru to democracy. He said he never intended to create a dictatorship when he launched his militarybacked crackdown on April 5 aimed at fighting corruption,展开更多
目的:检索大数据与健康相关的SCI论文,分析当前该领域的研究方向。方法:对Web of Science^(TM)核心合集数据库中该主题的SCI论文进行文献计量学分析,统计频次大于等于28次的高频主题词并生成共现矩阵,使用SPSS软件进行聚类分析,进而获...目的:检索大数据与健康相关的SCI论文,分析当前该领域的研究方向。方法:对Web of Science^(TM)核心合集数据库中该主题的SCI论文进行文献计量学分析,统计频次大于等于28次的高频主题词并生成共现矩阵,使用SPSS软件进行聚类分析,进而获得该领域的研究热点。结果:经检索得出相关论文979篇,高频主题词14个,获得该领域六个主要研究热点。结论:近年来有关大数据与健康相关的SCI论文主要研究方向包括:人口患病率研究、儿童健康领域研究、卫生保健领域研究、护理质量的效果与控制、健康和风险研究、疾病死亡率研究。展开更多
文摘Optical microscopy, and scanning electron microscopy in conjunction with energy dispersed X-ray spectrometry （SEM-EDX）, have been used to study the minerals and the concentrations of 12 trace elements in the No.14 coal from the Huolinhe mine, Inner Mongolia China. The distribution, affinity and removability of the trace elements were studied by float-sink experiments and petrological methods. A high mineral content, dominated by clay minerals, was found in the No.14 coal from the Huolinhe mine. The concentrations of As, Sb and Hg are relatively high compared to the average values for Chinese coals. As, Cr, Hg, Li, Mn, Pb are mainly associated with the minerals while Cd, Co, Ni, Sb, and Se are evenly distributed between the minerals and the organic matter. Be and Ba are mainly distributed in the minerals with a minor proportion in the organic matter. Most elements have a low organic affinity, although Sb, Se, Co, Cd, Ni are closely integrated with the organic matter. High theoretical removabilities are indicated for most trace elements. So it may be possible to lower the concentrations of trace elements during coal preparation.
文摘In his first speech on February 17 to a joint session of Congress, US President Bill Clinton outlined his wision of smaller deficits through higher income taxes on the wealthy, increased energy taxes and selected spending cuts including a one-year freeze on federal pay. US Secretary of State Warren Christopher arrived in Cairo on February 18 to start his six nation Middle East tour which will also take him to Jordan, Syria, Saudi Arahia, Kuwait, Israel and Lebanon.
文摘China announced on April 16 its decision to send military observers and engineers to join UN transitional authorities in Cambodia. The contingent left Beijing on the same day. On April 21, Peruvian President Alberto Fujimori announced a 12-month plan to return Peru to democracy. He said he never intended to create a dictatorship when he launched his militarybacked crackdown on April 5 aimed at fighting corruption,
文摘目的:检索大数据与健康相关的SCI论文,分析当前该领域的研究方向。方法:对Web of Science^(TM)核心合集数据库中该主题的SCI论文进行文献计量学分析,统计频次大于等于28次的高频主题词并生成共现矩阵,使用SPSS软件进行聚类分析,进而获得该领域的研究热点。结果:经检索得出相关论文979篇,高频主题词14个,获得该领域六个主要研究热点。结论:近年来有关大数据与健康相关的SCI论文主要研究方向包括:人口患病率研究、儿童健康领域研究、卫生保健领域研究、护理质量的效果与控制、健康和风险研究、疾病死亡率研究。
