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491.
Mayumi Allinson Brian Williams Graeme Allinson Michelle Graymore Frank Stagnitti 《毒物与环境化学》2013,95(3-4):401-414
Dithianon formulations are unstable in slightly basic aqueous solutions (pH 9, 20°C, t ½ = 5.6 h) but relatively stable in neutral or acidic solution (pH 4,20°C, t ½ = 6443 h). To ensure the efficacy of this fungicide it is important to prepare the spray mix fresh with neutral or slightly acidic water. Dithianon is unstable towards natural sunlight in the solid and aqueous phase, with half‐lives of approximately 68 and 42 days, respectively. Thermal hydrolysis does not seem to be the preferred degradation pathway when aqueous solutions are heated by the South Australian summer sun. The major aqueous phase photodegradation product has been identified as 2,3‐dihydro‐1,4‐dithiaanthraquinone. These results strongly suggest that should dithianon be accidentally released into basic Australian waters then it is likely to be rapidly chemically hydrolysed and pose little long term environmental threat. However, dithianon is only slowly chemically and photo‐lytically hydrolysed in neutral and acidic waters, and in this case accidentally release may pose a significant short term environmental threat. 相似文献
492.
为了有效、科学地对金属矿采空区的稳定性进行评价,提出基于改进突变级数法的采空区稳定性分析模型。根据改进突变级数法,对影响采空区稳定的9个因素进行多层次分解,并运用主成分分析法确定各层指标的相对重要性,以获得采空区稳定性评价指标体系。为得到最后的评价结果,对数据进行归一化处理,并结合突变理论与模糊数学理论,进行综合量化运算。利用搜集的26组地下金属矿采空区数据,对该评价模型进行训练和检验。研究表明,该评价模型既有效地避免了直接使用难于确定的“权重”概念,又客观地确定了各层指标的相对重要性,其判别结果比较符合实际,为金属矿采空区稳定性评价提供了一种新方法。 相似文献
493.
Improvement of the assimilable organic carbon (AOC) analytical method for reclaimed water 总被引:2,自引:0,他引:2
Xin ZHAO Hongying HU Shuming LIU Feng JIANG Xiaolei SHI Mingtang LI Xueqiao XU 《Frontiers of Environmental Science & Engineering》2013,7(4):483-491
Microbial growth is an issue of concern that may cause hygienic and aesthetic problems during the transportation and usage of reclaimed water. Assimilable organic carbon (AOC) is an important parameter which determines the heterotrophic bacterial growth potential of water. Pseudomonas fluorescens P17 and Spirillum sp. NOX are widely used to measure AOC in drinking water. The AOC values of various reclaimed water samples determined by P17 and NOX were compared with those determined by the new strains isolated from reclaimed water in this study. It showed that the conventional test strains were not suitable for AOC measurement of reclaimed water in certain cases. In addition to P17 and NOX, Stenotrophomonas sp. ZJ2, Pseudomonas saponiphila G3 and Enterobacter sp. G6, were selected as test strains for AOC measurement of reclaimed water. Key aspects of the bioassay including inoculum cell density, incubation temperature, incubation time and the pH of samples were evaluated for the newly selected test strains. Higher inoculum density (104 CFU·mL-1) and higher incubation temperature (25°C) could reduce the time required for the tests. The AOC results of various collected samples showed the advantages of the method proposed based on those five strains in evaluating the biologic stability of reclaimed water. 相似文献
494.
为促进高GC含量基因在荧光假单胞菌(Pseudomonas fluorescens)中表达效果更加理想、操作更加简便,本研究首先采用不依赖基因序列和连接反应的克隆(Sequence and ligation independent cloning,SLIC)方法将载体pCIBhis上与复制相关的序列和标记基因片段构建成克隆载体pCIBS1.然后优化荧光假单胞菌转化方法,用电转化法将pCIBS1导入荧光假单胞菌BL915中,随后又将T7和tac基因启动子分别插入pCIBS1中,成功构建了表达载体pCIBS3和pCIBS2.研究发现载体pCIBS1在大肠杆菌和荧光假单胞菌中均较为稳定,并且将绿色荧光蛋白基因插入表达载体中,在大肠杆菌BL21(DE3)中获得表达,验证了表达载体功能.本研究构建的表达载体和建立的荧光假单胞菌BL915电转化方法,为高GC含量基因在荧光假单胞菌中的表达奠定了基础. 相似文献
495.
Chun-Ping Lin Jo-Ming TsengYi-Ming Chang Yen-Chun ChengHsing-Yu Lin Ching-Yun Chien 《Journal of Loss Prevention in the Process Industries》2012,25(1):1-7
Liquid organic peroxides, such as tert-butyl peroxybenzoate (TBPB), have been widely employed in the petrifaction industry as a polymerization formation agent. This study investigated the thermokinetic parameters of TBPB by isothermal kinetic algorithms and non-isothermal kinetic equations, using thermal activity monitor III (TAM III) and differential scanning calorimetry (DSC), respectively. Simulations of 0.5 L, 25 kg, 55 gallon, and 400 kg reactors in liquid thermal explosion models were performed and compared to the results in the literature. A green thermal analysis was developed for a reactor containing TBPB to prevent pollution and reduce the energy consumption by thermal decomposition. It is based on the thermal hazard properties, such as the heat of decomposition (ΔHd), activation energy (Ea), self-accelerating decomposition temperature (SADT), control temperature (CT), emergency temperature (ET), and critical temperature (TCR). From the experimental results, the optimal conditions to avoid violent runaway reactions during the storage and transportation of TBPB were determined. 相似文献
496.
韩颖 《中国个体防护装备》2012,(3):23-26
有证实物标准样品"石材放射性标准样品"、"陶瓷产品的放射性标准样品"及"粉煤灰砌块的放射性标准样品"适用于γ谱仪校准和考核相近基质样品中所含放射性核素226Ra、232Th和40K含量测定的准确性,覆盖了建材产品需要检验的所有核素,达到放射平衡。样品由8家权威放射性检测机构采用低本底多道γ能谱仪测量方法进行定值测量,均匀性和稳定性良好,以对人们的安全与健康提供保护。 相似文献
497.
基于模糊随机可靠性的边坡稳定性评价 总被引:1,自引:0,他引:1
付士根 《中国安全生产科学技术》2012,8(8):98-101
影响边坡稳定性的因素中包含有很多的不确定性,这些不确定因素既具有随机性也具有模糊性。基于模糊分析理论,建立了模糊随机可靠性分析模型,提出了边坡模糊随机可靠性分析的点估计法,并运用该方法对一露天矿边坡稳定的的可靠性进行分析,通过对影响边坡稳定的各个力学参数进行模糊处理,然后应用统计矩点估计方法估计边坡的安全系数均值和可靠度,得出边坡的失稳概率。这种方法由于考虑到了各个力学参数的模糊性,比较符合客观实际,因而更具有实际指导意义。 相似文献
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