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811.
运用小波变换方法分析了跨断层形变观测资料不同尺度的小波变换的细节信号变化特征.研究结果表明:1)不同尺度小波变换分解的细节信号显示出不同的时变特征.当尺度为1时,日均值的细节信号主要为噪声;尺度为2、4时,日均值细节信号主要为非平稳信号;尺度为5、6时,细节信号主要为平稳周期信号;2)每月观测一次和每4月观测一次的跨断层形变资料在尺度为3时的细节信号有较好的年周期特征;3)关中地区垂直形变小波处理结果与测点附近200km左右范围内的中强地震有较好的对应关系,口镇-关山断裂2005年最新资料显示异常,应给予关注.  相似文献   
812.
膨润土改性及其在分散大红溶液脱色处理中的应用   总被引:26,自引:1,他引:26  
采用新型无机—有机改性方法,对浙江临安膨润土进行改性,有效地将双长链阳离子表面活性剂引入膨润土层间,从而提高了有机膨润土的亲油性和对废水中有机污染物的吸附能力。  相似文献   
813.
Aperspectiveanalysisonmunicipalsolidwaste(MSW)energyrecoveryinChinaHePinjing,ShaoLimingNationalLaboratoryofPolutionControlan...  相似文献   
814.
城市垃圾与排水污泥混合堆肥配比的研究   总被引:6,自引:0,他引:6  
配比是城市垃圾与排水系统污泥(污水厂污泥和管道污泥)混合堆肥工艺的关键参数。研究以理论和实验分析的方法,确定了合理的实验方法,即以堆反原料参数空隙率与堆肥过程评价参数(稳定周期或过程平均耗氧速率)的实验数据相关分析来确定适宜配比值域。城市垃圾与污水厂污泥适宜配比,城市垃圾与污水厂污泥、管道污泥适宜配比,分别为0.26~0.38、0.3~0.4(总污泥重量分率)。  相似文献   
815.
高强度开发下的上海农业环境问题与对策   总被引:6,自引:0,他引:6  
文章指出高强度开发下上海市郊主要的农业污染问题,并分析了污染形成的原因,提出了符合可持续发展战略的污染探讨对策。  相似文献   
816.
The mechanisms for dust emission involve the saltation of sand-sized particles and the transfer of momentum from the atmosphere to the surface. Roughness elements on aeolian surfaces influence the transfer of momentum through the partition of total momentum flux into a pressure drag on roughness elements and a skin drag on substrate surface. The objective of this study is to better understand the mechanisms for momentum transfer over rough surfaces and drag partition, so that better dust-emission parameterization schemes can be developed. A large-eddy simulation model is implemented for the purpose. We perform computational simulations of turbulent flows over individual and arrays of roughness elements. Further, we examine how roughness elements affect drag partition and dust emission. The results lead to a possible new concept of dust emission over rough surfaces.  相似文献   
817.
通过对长输石油管道打孔盗油各种形式的分析,提出相应的安全修复方法及作业要点,阐述了为使修复作业能够在安全状态下进行,抢维修单位应该事先做好的一些方面的工作.  相似文献   
818.
Ecosystem health assessment is one of the most important issues in regional ecological quality and safety studies. It also has a great significance to ecological conservation and regional development. This study focused on assessing the health status of forest, agriculture and urban ecosystems in the southwestern Beijing, China, including the Fangshan and Fengtai Districts. Based on field surveys and data collection, an assessment index system containing the vigor, organization and resilience factors was developed to measure the ecosystem health. Each index was scored from 1 to 5, representing five levels that contribute to the whole ecosystem health. The analytic hierarchy process (AHP) method was used to measure the weights of each index and three factors, and thus an overall score for a certain ecosystem was calculated. The results show that the forest ecosystem in the Fangshan District had higher health value than the Fengtai District, while the urban ecosystem had a slightly lower value in the Fangshan District than the Fengtai District. Both districts show lower resilience values in forest and urban ecosystems. Maintaining the ecosystem health will definitely benefit the long-term development of two districts. This study suggested that an approach for assessing the regional ecosystem health could be further developed to address spatial and synergy relationships between ecosystems and the three health factors.  相似文献   
819.
建筑涂料生产废水的处理技术   总被引:3,自引:0,他引:3  
采用混凝沉淀-芬顿试剂催化氧化-活性炭吸附工艺对建筑涂料生产废水的处理进行了研究。用硫酸铝作混凝剂,投加量为500mg/L:芬顿试剂法处理的废水pH为6.0,H2O2/COD值为4.0,FeSO4投加量为1540mg/L,氧化反应时间大于4h;活性炭投加量为0.2g/L时,处理后出水COD小于100mg/L。  相似文献   
820.
Guangzhou is a city in southern China that has experienced very rapid economic development in recent years. The city's air has very high concentrations of various pollutants, including sulphur dioxide (SO2), oxides of nitrogen (NOx), ozone (O3) and particulate. This paper reviews the changes in air quality in the city over the past 15 years, and notes that a serious vehicular-related emissions problem has been superimposed on the traditional coal-burning problem evident in most Chinese cities. As NOx concentrations have increased, oxidants and photochemical smog now interact with the traditional SO2 and particulate pollutants, leading to increased health risks and other environmental concerns.
Any responsible NOx control strategy for the city must include vehicle emission control measures. This paper reviews control strategies designed to abate vehicle emissions to fulfill the city's air quality improvement target in 2010. A cost-effectiveness analysis suggests that, while NOx emission control is expensive, vehicular emission standards could achieve a relatively sizable emissions reduction at reasonable cost. To achieve the 2010 air quality target of NOx, advanced implementation of EURO3 standards is recommended, substituting for the EURO2 currently envisioned in the national regulations. Related technical options, including fuel quality improvements and inspection/maintenance (I/M) upgrades (ASM or IM240), are assessed as well.  相似文献   
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