The concentration ranges of As and Sb in six Late Permian high-arsenic coals collected from Xingren and Xingyi, Guizhou Province are 94.1 μg·g -1-3 2 and 8 1 μg·g -1-120 μg·g -1, respectively. Based ...The concentration ranges of As and Sb in six Late Permian high-arsenic coals collected from Xingren and Xingyi, Guizhou Province are 94.1 μg·g -1-3 2 and 8 1 μg·g -1-120 μg·g -1, respectively. Based on the mineralogical analysis, no arsenic and arsenic-bearing minerals are detected in these samples and arsenic occurs in coal macerals. By extended X-ray absorption fine structure(EXAFS) spectroscopy, we have found that arsenic in these high-arsenic coal samples coordinates with oxygen; the coordination number of As with oxygen for these samples is 4 except one sample(H-9) for which the coordination number of As is 3. Therefore, arsenic in these high-arsenic coals does not occur in sulfide minerals, but occurs in arsenate or arsenite phase, and the preponderance of As is in arsenate of As 5+.展开更多
Nuclear fuel cycle chemistry is a growing interdisciplinary field that includes radiochemistry, nuclear chemistry, and radiation chemistry. It covers a diverse range of topics in- cluding the basic chemistry of actini...Nuclear fuel cycle chemistry is a growing interdisciplinary field that includes radiochemistry, nuclear chemistry, and radiation chemistry. It covers a diverse range of topics in- cluding the basic chemistry of actinides and fission products, nuclear chemistry and radiochemistry related to the nuclear fuel cycle, separation science, and isotope production. As a high-density form of energy that has almost no as- sociated discharge of greenhouse gases, nuclear energy plays a pivotal role in long-term energy security and the prevention of global warming. Although the accident at the Fukushima nuclear power plant has raised intense public concern about the safety of nuclear energy around the world, we believe that nuclear energy is still an inevitable option to ensure energy supply and to reduce carbon emissions in many countries. However, to realize the sustainable devel- opment of nuclear energy in the future it is necessary to maximize uranium resources and minimize radioactive waste. An advanced nuclear fuel cycle can efficiently use uranium resources and reduce the volume and radiotoxicity of nuclear waste, thus greatly contributing to the peaceful use of nuclear power by mankind.展开更多
Synchrotron X-ray fluorescence analyses of crystal and amorphous clinopyroxene were compared. The results showed that using the synchrotron X-ray as a source of energy, the diffraction X-ray of crystal materials will ...Synchrotron X-ray fluorescence analyses of crystal and amorphous clinopyroxene were compared. The results showed that using the synchrotron X-ray as a source of energy, the diffraction X-ray of crystal materials will seriously affect the X-ray fluorescence analysis. In order to avoid the influence of diffraction, the best way to solve it is to use the monochromatic source, or to have a collimating slit between sample and Si(Li) detector.展开更多
The basic dyke swarms, which have been deformed and metamorphosed, are widespread in the Wudang block. They are geochemically characterized by the continental tholeiites, and their Sm Nd isochron age is (782±164)...The basic dyke swarms, which have been deformed and metamorphosed, are widespread in the Wudang block. They are geochemically characterized by the continental tholeiites, and their Sm Nd isochron age is (782±164) Ma. All of these indicate that there was an ancient continental block in the Proterozoic and a rifting occurring on this continental block during ±800 Ma.展开更多
Whether the platinum group elements (PGE) can be taken as the indicators of extraterrestrial materials is a very important and interesting scientific problem. It is discussed on the basis of systematic investigation a...Whether the platinum group elements (PGE) can be taken as the indicators of extraterrestrial materials is a very important and interesting scientific problem. It is discussed on the basis of systematic investigation and study of a great amount of related literature. The following conclusions can be obtained: (ⅰ) extraterrestrial impact event can cause the PGE anomaly; conversely, the PGE anomaly may not represent the existence of extraterrestrial impact event, because the PGE anomaly can be caused by many terrestrial events (e.g. volcanic activity); (ⅱ) the PGE anomaly, especially the global PGE anomaly can inspire us to think it from extraterrestrial event, but it may not be as useful as previously thought as unambiguous identifiers of large extraterrestrial impact event in the earth’s history.展开更多
文摘The concentration ranges of As and Sb in six Late Permian high-arsenic coals collected from Xingren and Xingyi, Guizhou Province are 94.1 μg·g -1-3 2 and 8 1 μg·g -1-120 μg·g -1, respectively. Based on the mineralogical analysis, no arsenic and arsenic-bearing minerals are detected in these samples and arsenic occurs in coal macerals. By extended X-ray absorption fine structure(EXAFS) spectroscopy, we have found that arsenic in these high-arsenic coal samples coordinates with oxygen; the coordination number of As with oxygen for these samples is 4 except one sample(H-9) for which the coordination number of As is 3. Therefore, arsenic in these high-arsenic coals does not occur in sulfide minerals, but occurs in arsenate or arsenite phase, and the preponderance of As is in arsenate of As 5+.
文摘Nuclear fuel cycle chemistry is a growing interdisciplinary field that includes radiochemistry, nuclear chemistry, and radiation chemistry. It covers a diverse range of topics in- cluding the basic chemistry of actinides and fission products, nuclear chemistry and radiochemistry related to the nuclear fuel cycle, separation science, and isotope production. As a high-density form of energy that has almost no as- sociated discharge of greenhouse gases, nuclear energy plays a pivotal role in long-term energy security and the prevention of global warming. Although the accident at the Fukushima nuclear power plant has raised intense public concern about the safety of nuclear energy around the world, we believe that nuclear energy is still an inevitable option to ensure energy supply and to reduce carbon emissions in many countries. However, to realize the sustainable devel- opment of nuclear energy in the future it is necessary to maximize uranium resources and minimize radioactive waste. An advanced nuclear fuel cycle can efficiently use uranium resources and reduce the volume and radiotoxicity of nuclear waste, thus greatly contributing to the peaceful use of nuclear power by mankind.
文摘Synchrotron X-ray fluorescence analyses of crystal and amorphous clinopyroxene were compared. The results showed that using the synchrotron X-ray as a source of energy, the diffraction X-ray of crystal materials will seriously affect the X-ray fluorescence analysis. In order to avoid the influence of diffraction, the best way to solve it is to use the monochromatic source, or to have a collimating slit between sample and Si(Li) detector.
文摘The basic dyke swarms, which have been deformed and metamorphosed, are widespread in the Wudang block. They are geochemically characterized by the continental tholeiites, and their Sm Nd isochron age is (782±164) Ma. All of these indicate that there was an ancient continental block in the Proterozoic and a rifting occurring on this continental block during ±800 Ma.
文摘Whether the platinum group elements (PGE) can be taken as the indicators of extraterrestrial materials is a very important and interesting scientific problem. It is discussed on the basis of systematic investigation and study of a great amount of related literature. The following conclusions can be obtained: (ⅰ) extraterrestrial impact event can cause the PGE anomaly; conversely, the PGE anomaly may not represent the existence of extraterrestrial impact event, because the PGE anomaly can be caused by many terrestrial events (e.g. volcanic activity); (ⅱ) the PGE anomaly, especially the global PGE anomaly can inspire us to think it from extraterrestrial event, but it may not be as useful as previously thought as unambiguous identifiers of large extraterrestrial impact event in the earth’s history.
