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41.
应用时间破裂分析方程中表征地震距释放程度的m值,选取不同空间尺度进行时空扫描研究,得到震前1年以每2个月为时间间隔的空间m值随时间变化的分布图像,运用不同参数设置计算了地震前Benioff累积应变释放特征。通过对比这些变化找出研究区内m值空间分布搜索主震破裂点扫描效果较好的参数模型,尝试性地给出了"矩释放程度空间扫描"方法应用于地震预测的经验指标。并结合与矩加速释放具有相同物理机制的加卸载响应比(Load/Unload Response Ratio)方法进行综合分析,利用这两种方法对地震进行中短期预测,达到两种方法互相检验、相互辅助的目的。考虑到本文仅对6个震例进行研究,无法给出具有统计显著性的结论,所以仍需结合其他方法进行点、线、面的综合分析。 相似文献
42.
A pilot-scale study of cryolite precipitation from high fluoride-containing wastewater in a reaction-separation integrated reactor 总被引:2,自引:0,他引:2
Fluoride removal by traditional precipitation generates huge amounts of a water-rich sludge with low quality, which has no commercial or industrial value. The present study evaluated the feasibility of recovering fluoride as low water content cryolite from industrial fluoride-containing wastewater. A novel pilot-scale reaction-separation integrated reactor was designed. The results showed that the seed retention time in the reactor was prolonged to strengthen the induced crystallization process. The particle size of cryolite increased with increasing seed retention time, which decreased the water content. The recovery rate of cryolite was above 75% under an influent fluoride concentration of 3500 mg/L, a reaction temperature of 50℃, and an influent flow of 40 L/hr. The cryolite products that precipitated from the reactor were small in volume, large in particle size, low in water content, high in crystal purity, and recyclable. 相似文献
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采用溶胶-凝胶法制备酞菁-TiO2光催化剂,并分别掺杂铁、铜、钴、镍元素。酞菁作为光敏化剂,提高TiO2在可见光下对有机染料的降解效果。采用SEM对催化剂进行表征,研究在可见光下酞菁-TiO2光催化剂对5种有机染料(甲基橙、甲基红、甲酚紫、亚甲基蓝和孔雀石绿)的降解效果,结果表明,酞菁铁-TiO2,酞菁钴-TiO2,酞菁铜-TiO2,酞菁镍-TiO2均能有效降解这几种有机染料,光催化反应300 min后降解率达92%。比较4种催化剂对甲基橙的降解率,酞菁钴-TiO2催化剂降解效果最明显,以下是酞菁铁、酞菁镍和酞菁铜-TiO2催化剂。 相似文献
45.
化石燃料原油和原煤的燃烧、含钒矿石的开采和冶炼是大气中重金属钒的主要来源。文章利用重金属钒的排放系数分析了中国1978-2010年人为过程释放到大气中重金属钒的总量和行业重金属钒的排放,预测了2020年和2030年中国大气中重金属钒的排放量。结果表明,自1978年以来,中国钒的排放量增加了4倍,中国2010年人类活动向大气排放的重金属钒总量达3.18万吨,约占世界总量的12%。原油燃烧释放到大气中的钒约占总量的85%,煤炭燃烧的排放量占10.5%,其中工业耗油向大气中释放重金属钒的比例从1980的71%下降到2008年的42%,总量从3 721 t增加至9 361 t;交通运输行业从10%上升到36%,总量从547 t增加至7 967 t;其它行业(农林牧渔水利业、批发零售业和住宿餐饮业、生活消费)基本维持在20%左右,总量从986 t增加至5 052 t。因此,应加强大气中钒的监测和管理,预防大气钒污染事件的发生。 相似文献
46.
论述了输油泵站控制系统及微波通信系统遭受雷击的危害及原因,有针对性地采取了各种防雷的有效措施,完善微波通讯和站控及网络防雷保护系统,为确保输油安全生产提供了有利保证. 相似文献
47.
48.
在硫酸系统中,通过水平衡分析计算烟气带入净化工序的SO2体积分数和含水量,确定净化工序的能力,控制干燥塔进口烟气温度,使干吸工序生产出合格产品;通过计算,烟气带入净化工序的水量小于产品带出的水量,制酸净化污水经过污水处理工序处理后返回到净化工序重复使用,实现净化污水零排放,消除对环境的污染. 相似文献
49.
Yanhui Li Bing Xi Quansheng Zhao Fuqiang Liu Pan Zhang Qiuju Du Dechang Wang Da Li Zonghua Wang Yanzhi Xia 《环境科学学报(英文版)》2011,23(3):404-411
Kaolin has been widely used as an adsorbent to remove heavy metal ions from aqueous solutions. However, the lower heavy metal
adsorption capacity of kaolin limits its practical application. A novel environmental friendly material, calcium alginate immobilized
kaolin (kaolin/CA), was prepared using a sol-gel method. The e ects of contact time, pH, adsorbent dose, and temperature on Cu2+
adsorption by kaolin/CA were investigated. The Langmuir isotherm was used to describe the experimental adsorption, the maximum
Cu2+ adsorption capacity of the kaolin/CA reached up to 53.63 mg/g. The thermodynamic studies showed that the adsorption reaction
was a spontaneous and endothermic process. 相似文献
50.
Historical trends of heavy metal contamination and their sources in lacustrine sediment from Xijiu Lake, Taihu Lake Catchment, China 总被引:3,自引:1,他引:2
Concentrations of Cd, Cr, Cu, Pb, Zn and Hg in Xijiu Lake sediment from the Taihu Lake catchment, China, were analyzed. Their contamination state was investigated based on the geoaccumulation index and enrichment factors. Statistical analysis was used to differentiate the anthropogenic versus natural sources of heavy metals (HMs), and the anthropogenic accumulation fluxes were calculated to quantify anthropogenic contribution to HMs. The results indicated that the lake sediment had been heavily contaminated by Cd, enrichment of Zn and Hg was at a relatively high level, while that of Cu and Pb was in the lower-to-moderate level and Cr was in the low enrichment level. Sources of Cr in the sediment were mainly from natural inputs, while other metals, especially Cd, were predominantly derived from anthropogenic sources. In the past century, anthropogenic accumulation fluxes of Pb, Zn and Hg increased by 0.1-47.3 mg/(cm2.yr), 2.4-398.1 mg/(cm2.yr), and 3.7-110.3 ng/(m2.yr), respectively, accounting for most inputs of HMs entering the sediment. The contamination state of HMs varied with industrial development of the catchment, which demonstrated that contamination started in the early 20th century, reached the maximal level between the mid-1970s and mid-1990s, and decreased a little after the implementation of constraints on high contamination industries, although the contamination of some HMs, such as Cd, Zn and Hg, is still at high levels. 相似文献