排序方式: 共有56条查询结果,搜索用时 265 毫秒
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研究了苯胺在土壤中的自然降解作用和化学氧化修复效果。结果表明:168h内自然降解方式对土壤中497.25mg·kg-1和1 195.67mg·kg-1苯胺的去除率分别为92.79%和92.88%;降解过程符合一级动力学方程,半衰期分别为49.51h和46.21h;自然降解过程主要依靠挥发和光降解。与自然降解相比,化学氧化修复具有修复效率高、修复周期短等优势。H2O2、Fenton试剂、类Fenton试剂、KMnO4和活化Na2S2O8等五种氧化剂中,活化Na2S2O8和KMnO4对土壤中苯胺的氧化去除率最高,分别为99.96%和99.20%,但氧化后样品上清液中氧化剂残留量高,均高于25%。类Fenton试剂对土壤中苯胺的氧化去除率可达99.00%,氧化后上清液中苯胺残留量和氧化剂残留量分别为0.97%和0.78%,是五种氧化剂中最理想的氧化剂。 相似文献
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Numerical simulation of March 11, 2011 Honshu, Japan tsunami 总被引:1,自引:0,他引:1
In order to predict tsunami hazards through numerical simulation,by using the focal mechanisms as well as fault parameters of Japan’s 2011 Tohoku Earthquake provided by National Geological Survey(referred to as USGS),we proposed a numerical model to simulate the Honshu,Japan tsunami.Numerical computing is conducted to investigate the security along the coast.We also analyzed the simulation results and distribution of tsunami disaster,trying to achieve a more reasonable tsunami warning program.Our numerical model is composed of simulation of surface deformation after the earthquake and the tsunami propagation process which is based on two dimensional shallow water equations.The simulation results show the characteristics of the tsunami propagation,and arrival times on recorder points are consistent with tsunami observation.This model can be applied to evaluate the security of the coastal area and obtain more accurate tsunami warning. 相似文献
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J. H. Thompson D. Aures L. Yuen M. Angulo 《Cellular and molecular life sciences : CMLS》1973,29(2):179-180
Zusammenfassung Nachweis, dass Pentagastrin (ICI-50123) 200 g/ml/kgh die Magensaftsekretion in der Shay-Ratte 2 h nach Ligatur des Pylorus erhöht. Die Histaminspeicher des Rattenmagens wurden reduziert und Histidindecarboxylase-Aktivität gesteigert. Verabreichung von 1000 mg/kg Histidin erhöht den basalen Histaminspiegel, jedoch wurde die Histidindecarboxylase-Aktivität bei normaler Magensaftsekretion nicht durch Pentagastrin induziert. 相似文献
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Genesis of a highly pathogenic and potentially pandemic H5N1 influenza virus in eastern Asia 总被引:4,自引:0,他引:4
Li KS Guan Y Wang J Smith GJ Xu KM Duan L Rahardjo AP Puthavathana P Buranathai C Nguyen TD Estoepangestie AT Chaisingh A Auewarakul P Long HT Hanh NT Webby RJ Poon LL Chen H Shortridge KF Yuen KY Webster RG Peiris JS 《Nature》2004,430(6996):209-213
A highly pathogenic avian influenza virus, H5N1, caused disease outbreaks in poultry in China and seven other east Asian countries between late 2003 and early 2004; the same virus was fatal to humans in Thailand and Vietnam. Here we demonstrate a series of genetic reassortment events traceable to the precursor of the H5N1 viruses that caused the initial human outbreak in Hong Kong in 1997 (refs 2-4) and subsequent avian outbreaks in 2001 and 2002 (refs 5, 6). These events gave rise to a dominant H5N1 genotype (Z) in chickens and ducks that was responsible for the regional outbreak in 2003-04. Our findings indicate that domestic ducks in southern China had a central role in the generation and maintenance of this virus, and that wild birds may have contributed to the increasingly wide spread of the virus in Asia. Our results suggest that H5N1 viruses with pandemic potential have become endemic in the region and are not easily eradicable. These developments pose a threat to public and veterinary health in the region and potentially the world, and suggest that long-term control measures are required. 相似文献
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Carbon isotope composition of low molecular weight hydrocarbons and monocarboxylic acids from Murchison meteorite 总被引:7,自引:0,他引:7
The origin of the organic matter in carbonaceous meteorites remains controversial despite extensive study over the past 20 yr. Motivated by the expectation that the patterns of isotopic variation with molecular structure among the organic compounds would contain important clues to their origin, we have measured the carbon isotopic compositions for individual hydrocarbons and monocarboxylic acids from Murchison meteorite, a C2 carbonaceous chondrite which fell in Australia in 1969. With few exceptions, notably benzene, the volatile products are substantially isotopically heavier than their terrestrial counterparts, signifying their extraterrestrial origin. For both classes of compounds, the ratio of 13C to 12C decreases with increasing carbon number in a roughly parallel manner, and each carboxylic acid exhibits a higher isotopic ratio than the hydrocarbon containing the same number of carbon atoms. These trends are consistent with the kinetically controlled synthesis of higher homologues from lower ones. The results suggest the possibility that the production mechanisms for hydrocarbons and carboxylic acids may be similar; they also impose constraints on the identity of the reactant species. 相似文献
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一种曲面网格优化的通用算法 总被引:5,自引:2,他引:3
提出了一种曲面网格优化的通用算法,该算法基于一些预先定义的优化准则,将给定的网格曲面优化成为单位网格曲面,定义了两种指导优化过程的优化标准。在优化过程中采用了三种优化算子(边分裂、边消除、边替换),是一个简单的曲面网格优化的通用算法。 相似文献
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Chan P. M. Yuen C. W. M. Yeung K. W.Institute of Textiles Clothing The Hong Kang Polytechnic University Hong Kong 《东华大学学报(英文版)》1999,(2)
The central composition experimental design of multiva-riate Response Surface Method was used to formulate mathematical models aiming to predict (1) the optimum dyeing conditions of simulated waste Tikuanyin tea for wool fabric and (2) the optimum extraction conditions of a natural mordant originated from common waste eggshell. The pre - mordanting eggshell was applied to wool fabric before dyeing with simulated waste Tikuanyin tea under the optimum dyeing conditions. After mordanting the wool fabric with extracted natural eggshell solution, the prominent effect of increment in dye uptake and improvement of the properties of light fastness, washing fastness and rubbing fastness were evaluated. 相似文献