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971.
自然灾害研究的新趋势——社会易损性分析 总被引:10,自引:4,他引:10
社会易损性分析在自然灾害及减灾中的重要性是近期才被认识到的。本文分析了自然灾害、易损性和灾难的概念,探讨了社会易损性的内容、分析评价方法及其应用。今后应充分注意社会易损性分析在自然灾害和减灾研究中的重要性,积极开展社会易损性分析和评价研究。 相似文献
972.
973.
974.
化工制药工艺残渣燃烧过程固氯研究 总被引:1,自引:0,他引:1
采用管式固定床反应器对化工制药工艺残渣的燃烧分解进行了实验研究,进一步通过加入氧化钙/碳酸钙来防止燃烧过程残渣中氯的释放.实验结果表明,残渣在燃烧时氯主要以氯化氢形式排出,加入固氯剂后能有效地抑制氯化氢的生成,且固氯效果随着钙化物投加量的增加而明显提高.当氧化钙/残渣比(质量比)达到0.8时,固氯率可达97%以上;当碳酸钙/残渣比(质量比)提高到2.0时,固氯率为76%.与此对应的Ca/Cl摩尔比分别为30和40.继续增加钙投加量,固氯效果基本不变.同时发现添加一定量的木屑在助燃的同时有助于提高固氯效果. 相似文献
975.
Temporal-spatial variability and fractal characteristics of soil nitrogen and phosphorus in Xinji District, Hebei Province, China 总被引:1,自引:0,他引:1
Rutai Gao Shuqing Liu Yigong Zhang Huizhuo Li Yuanfang Huang Xunfeng Xia Tiantian Jiang Hui Zhang 《Environmental monitoring and assessment》2011,174(1-4):229-240
Traditional statistics, geostatistics, fractal dimensions, and geographic information systems (GIS) were employed to study the temporal?Cspatial variability of soil total nitrogen (TN) and total phosphorus (TP) levels in Xinji District, Hebei Province area of the North China Plain from 1980 to 2007. The results indicate that nutrient levels follow normal or lognormal distributions. The TN content was 0.59 ±0.155 g kg???1 in 2007, an increase of 0.44 g kg???1 compared with that of 1980. In 2007, the TP content was 1.21 ±0.227 g kg???1, an increase of 0.01 g kg???1 from 1980. The geostatistical analysis showed that the distribution of these soil nutrients in the study area exhibits a trend and anisotropy. The range and [C 0/(C 0?+?C)] of TN and TP in 1980 were all less than in 2007. The ordinary kriging interpolation method was used to analyze the nutrient contents differences between 1980 and 2007. The results indicate that soil TN levels have increased over the 27-year period, and the area where the TN level had increased by at least 0.4 g kg???1 was about 61.7% of the district. The area where the TP content increased covered about 58.4% of the district. The variance analysis indicated that land-use type had a clear influence on the distribution and change in TN and TP content. Using the 3-D box-counting dimension method combined with GIS, the fractal dimension of soil nutrient spatial distribution over the two periods showed that in 27 years, the fractal dimension of TN increased from 1.95 to 2.02, and the fractal dimension of TP increased from 1.89 to 2.01, indicating that the complexity of the spatial distribution of all nutrient contents had increased. This study can provide a basis for accurate fertilizing and to enhance the conversion of soil characteristics under different spatial scales. 相似文献
976.
Jiang JG 《Environmental pollution (Barking, Essex : 1987)》2006,139(2):306-317
We developed a new biotic index of species pollution value (SPV) and community pollution value (CPV) based on the correlation of protozoan communities with chemical water quality to assess freshwater pollution. Five hundred and twenty-three species of protozoa SPV were established based on the data of River Hangjiang and Lake Donghu. The present research was conducted in order to further consummate the biotic index. Protozoa of the water system in Changde City were collected from 16 stations using the PFU method and the water chemical parameters of the stations were analyzed. The results showed that CPV calculated from SPV had a close correlation with the degree of water pollution (p < 0.00001), which indicated that the method is reliable. By combining the data of River Hangjiang, Lake Donghu and Changde City, the final form of SPV was accomplished and the SPV list increased to 757. The ultimate water standard evaluated by CPV calculated from SPV was proposed. 相似文献
977.
978.
我国正在研制专用于销毁高浓度多氯联苯(PCBs)的焚烧炉,主要处理废旧的含(PCBs)的电力电容器和变压器,应用可靠准确的监测方法测定了试验性焚烧炉渣、烟灰排气和废水中的二口恶口英(dioxins),类二口恶口英多氯联苯(dioxinlikePCBs)和PCBs含量,结果表明该炉试烧高浓度PCBs时,焚毁率可以达到99.9999%,炉渣中的2,3,7,8TCDD毒性当量为87.86pgTEQ/g,烟灰中残留二口恶口英和类二口恶口英的总2,3,7,8TCDD毒性当量为47.23ngTEQ/g. 相似文献
979.
980.
Hui ZHANG Le XU Yifei ZHANG Mengchan JIANG 《Frontiers of Environmental Science & Engineering》2016,10(2):336-340
The release of pollutants from sewage sludge in the treatment process is a worldwide tricky problem in the field of sludge treatment. In this paper, the release and reaction between monomers of polycyclic aromatic hydrocarbons (PAHs) in the sewage sludge incineration treatment were studied based on simulated experiments. The result indicates that the transformation may occurre between monomers of PAHs during their release in the treatment. Over 90% of total PAHs in sewage sludge are released at the the temperature of 300°C–750°C. The possible transformation of Naphthalene to indeno(1, 2, 3-cd)pyrene was related to the temperature of the treatment system. Here, we showed that the output rate of transformation reactions for indeno(1, 2, 3-cd)pyrene is 94% at 300°C. These findings, by identifying corresponding treatment conditions as well as techniques, can help to understand the reactions and control real outputs of PAHs in the treatment process. 相似文献