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161.
循环经济条件下,政府制度安排与政策制定需要考虑更多利益主体。引入动态博弈理论的有关成果,通过建立政府与企业在循环经济背景下的博弈模型,对两者的行为进行分析,从而对循环经济背景下政府制度设计与政策制定提出建议。  相似文献   
162.
研究了游离细胞与载体吸附培养、不同载体材料对Phanerochaete chrysosporium进行连续染料脱色及产酶能力的影响。结果表明,P. chrysosporium可在载体上良好生长,甚至生长到载体内部。木屑、玉米芯、花生壳3种载体材料中,以木屑载体吸附培养物的持续脱色和产酶效果最佳,该培养物经三轮连续脱色后对染料RB5仍能达到最高95%的脱色率,并产生596 U/L锰依赖过氧化物酶(MnP)和1 326 U/L木质素过氧化物酶(LiP),对染料的持续脱色和产酶能力明显优于游离细胞培养物。  相似文献   
163.
采用四步连续提取法提取不同季节南京仙林地区PM_(2.5)中不同化学形态的金属组分。结果显示:(1)PM_(2.5)日均值平均为84.93μg/m3,75%的样品超过了《环境空气质量标准》(GB 3095—2012)中PM_(2.5)日均值二级标准值(75μg/m~3)。(2)PM_(2.5)中Fe、Zn和Pb浓度最高,As和Cd浓度最低。(3)Zn、Cd和Mn主要以弱酸提取态(F1)存在,Pb以可还原态(F2)为主,As主要以F1和F2存在,Ni和Cr以F1和可氧化态(F3)为主,Cu主要为F1、F2、F3,Fe和Ti大部分以残渣态(F4)存在。(4)Zn具有非常高的环境风险,Cd、As、Cu和Mn均表现出高风险,Pb、Ni和Cr具有中等风险,Fe、Ti具有低风险。(5)对于儿童,Cr具有潜在致癌风险;对于成人,As和Cr具有潜在致癌风险。  相似文献   
164.
中国现行的固体废物氰化物总量和氰化物浸出毒性的分析方法存在缺陷,不便于广泛指导监测工作,笔者优化了固体废物氰化物测定的前处理方法,明确了固体废物氰化物总量、氰化物浸出毒性测定时的样品粒径、浸提方法和消解方法,建立了容量法、分光光度法、流动注射法测定固体废物氰化物总量和浸出毒性的方法,并与标准方法(离子色谱法)进行比较。实验结果表明:容量法、分光光度法、流动注射法测定结果与离子色谱法无显著差异,3种方法测定固体废物氰化物总量加标回收率为80.5%~102%,平行样测定相对标准偏差为3.0%~6.9%,3种方法测定固体废物氰化物浸出毒性加标回收率为80.1%~107%,平行样测定相对标准偏差为7.8%~9.5%,3种方法测定结果精密度和准确度良好,均能够满足固体废物氰化物总量和氰化物浸出毒性的测定要求。其中容量法、分光光度法由于其仪器设备简单、操作简便,可用于突发环境事件应急监测等情况下固体废物氰化物的测定。但容量法检出限较高,不能满足评价标准较低的分析测试工作要求,离子色谱法、分光光度法和流动注射法检出限均能满足一般分析测试要求。  相似文献   
165.
In atmospheric environment, the layout difference of urban buildings has a powerful influence on accelerating or inhibiting the dispersion of particle matters (PM). In industrial cities, buildings of variable heights can obstruct the diffusion of PM from industrial stacks. In this study, PM dispersed within building groups was simulated by Reynolds-averaged Navier-Stokes equations coupled Lagrangian approach. Four typical street building arrangements were used: (a) a low-rise building block with Height/base H/b = 1 (b = 20 m); (b) step-up building layout (H/b = 1, 2, 3, 4); (c) step-down building layout (H/b = 4, 3, 2, 1); (d) high-rise building block (H/b = 5). Profiles of stream functions and turbulence intensity were used to examine the effect of various building layouts on atmospheric airflow. Here, concepts of particle suspension fraction and concentration distribution were used to evaluate the effect of wind speed on fine particle transport. These parameters showed that step-up building layouts accelerated top airflow and diffused more particles into street canyons, likely having adverse effects on resident health. In renewal old industry areas, the step-down building arrangement which can hinder PM dispersion from high-level stacks should be constructed preferentially. High turbulent intensity results in formation of a strong vortex that hinders particles into the street canyons. It is found that an increase in wind speed enhanced particle transport and reduced local particle concentrations, however, it did not affect the relative location of high particle concentration zones, which are related to building height and layout.

Implications: This study has demonstrated the height variation and layout of urban architecture affect the local concentration distribution of particulate matter (PM) in the atmosphere and for the first time that wind velocity has particular effects on PM transport in various building groups. The findings may have general implications in optimization the building layout based on particle transport characteristics during the renewal of industrial cities. For city planners, the results and conclusions are useful for improving the local air quality. The study method also can be used to calculate the explosion risk of industrial dust for people who live in industrial cities.  相似文献   

166.
Urban tinkering     
Cities are currently experiencing serious, multifaceted impacts from global environmental change, especially climate change, and the degree to which they will need to cope with and adapt to such challenges will continue to increase. A complex systems approach inspired by evolutionary theory can inform strategies for policies and interventions to deal with growing urban vulnerabilities. Such an approach would guide the design of new (and redesign of existing) urban structures, while promoting innovative integration of grey, green and blue infrastructure in service of environmental and health objectives. Moreover, it would contribute to more flexible, effective policies for urban management and the use of urban space. Four decades ago, in a seminal paper in Science, the French evolutionary biologist and philosopher Francois Jacob noted that evolution differs significantly in its characteristic modes of action from processes that are designed and engineered de novo (Jacob in Science 196(4295):1161–1166, 1977). He labeled the evolutionary process “tinkering”, recognizing its foundation in the modification and molding of existing traits and forms, with occasional dramatic shifts in function in the context of changing conditions. This contrasts greatly with conventional engineering and design approaches that apply tailor-made materials and tools to achieve well-defined functions that are specified a priori. We here propose that urban tinkering is the application of evolutionary thinking to urban design, engineering, ecological restoration, management and governance. We define urban tinkering as:
A mode of operation, encompassing policy, planning and management processes, that seeks to transform the use of existing and design of new urban systems in ways that diversify their functions, anticipate new uses and enhance adaptability, to better meet the social, economic and ecological needs of cities under conditions of deep uncertainty about the future.
This approach has the potential to substantially complement and augment conventional urban development, replacing predictability, linearity and monofunctional design with anticipation of uncertainty and non-linearity and design for multiple, potentially shifting functions. Urban tinkering can function by promoting a diversity of small-scale urban experiments that, in aggregate, lead to large-scale often playful innovative solutions to the problems of sustainable development. Moreover, the tinkering approach is naturally suited to exploring multi-functional uses and approaches (e.g., bricolage) for new and existing urban structures and policies through collaborative engagement and analysis. It is thus well worth exploring as a means of delivering co-benefits for environment and human health and wellbeing. Indeed, urban tinkering has close ties to systems approaches, which often are recognized as critical to sustainable development. We believe this concept can help forge much-closer, much-needed ties among engineers, architects, evolutionary ecologists, health specialists, and numerous other urban stakeholders in developing innovative, widely beneficial solutions for society and contribute to successful implementation of SDG11 and the New Urban Agenda.
  相似文献   
167.
Heavy metal induced ecological risk in the city of Urumqi, NW China   总被引:2,自引:0,他引:2  
A total of 169 samples of road dust collected in the city of Urumqi, capital of the Xinjiang Uygur Autonomous Region in northwest China, were analyzed by method of inductively coupled plasma-mass spectrometry for 10 elements (i.e., Cd, Cr, Cu, Ni, Pb, Mn, Be, Co, Zn, and U). The possible sources of metals are identified with multivariate analysis such as correlation analysis, principal component analysis, and cluster analysis. Besides, enrichment factors are used to quantitatively evaluate the influences of human activities on heavy metal concentrations. Moreover, the potential ecological risk index is applied to evaluating the ecological risk of heavy metal pollutants. The results indicate that: (1) the concentrations of the heavy metals involved were much higher in urban areas than the background values, except those of Co and U. Mn, U, and Co are mainly of natural origin; Cu, Pb, Zn, and Cr are mainly of traffic sources and are partly of industrial sources; Ni and Be are mainly the results of industrial activities, such as machine shops, firepower plants, tire and rubber factories, cement factories, and textile mills and are partly of the traffic sources; (2) with high “toxic-response” factor and high concentration, Cd has more serious influences on the environment than other heavy metals. Therefore, commercial and industrial areas are usually characterized by higher potential ecological risk when compared with residential areas and new developing urban areas. The results of this study could be helpful for the management of environment in industrial areas.  相似文献   
168.
利用2002-2007年5~10月烟台市四十里湾赤潮多发海域的实际监测数据,采用spearman秩相关系数法对海域主要环境因子的变化趋势及与海域赤潮发生的关系进行了分析.分析结果表明,2002-2007年海域水质透明度、盐度、无机氮呈下降趋势,表层水温、磷酸盐、表层DO、pH、叶绿素a及COD呈上升趋势;发生赤潮年份表层水温较高,透明度较低,盐度较低,无机氮与磷酸盐比值(DIN/DIP)发生变化,海水pH偏高,COD升高;赤潮前期DO较高,赤潮间DO降低;叶绿素a与赤潮呈明显的正相关.  相似文献   
169.
Li X  Zhang Q  Dai J  Gan Y  Zhou J  Yang X  Cao H  Jiang G  Xu M 《Chemosphere》2008,72(8):1145-1151
Organochlorine pesticides (OCPs, including DDT, HCH and HCB) and six indicator polychlorinated biphenyls (PCB 28, 52, 101, 138, 153, and 180) were measured in water, sediment, zooplankton, fish and Chinese softshell turtle (Pelodiscus sinensis) from Gaobeidian Lake, which is located in the effluent of Gaobeidian wastewater treatment plant (WWTP) in Beijing, China. DDTs were dominant except for in water. In water, the concentrations of DDTs (6.22 ng l(-1)) and HCHs (18.0 ng l(-1)) were less than the limits (l000 ng l(-1) for DDTs and 5000 ng l(-1) for HCHs). However, PCBs concentration (20.8 ng l(-1)) exceeded the limit (14 ng l(-1)) suggested by the United States Environmental Protection Agency (USEPA). The high ratio of p,p'-DDT/DDTs (0.80) in water suggested that DDTs had recently been discharged into the ambient environment despite a longtime ban in China. For fish and Pelodiscus sinensis, the accumulation patterns of OCPs and PCBs were different in muscle and liver. And HCB and PCB 153 were significant different in different species (p<0.05). PCBs were dominated by PCB 52 in zooplankton, but by PCB 138 and 153 in Pelodiscus sinensis. The highest food web magnification factor (FWMF) was 4.83 for p,p'-DDT and the second highest was 4.36 for PCB 101 in Gaobeidian Lake. As compared with the other studies, biomagnification in the present study was not obvious. Trophic levels and age were two important factors that might contribute to the bioaccumulation in the present study.  相似文献   
170.
我国城市内涝灾害的影响因子及气象服务对策   总被引:2,自引:0,他引:2  
近年来,一场暴雨导致某座现代化大都市部分功能瘫痪、生命财产损失惨重的案例屡见不鲜。以山西为例,通过分析认为城市化导致大城市降水量和强降水事件增多、城市规划和排水管网建设滞后、完善的城市内涝灾害气象服务体系尚未建立等是造成城市内涝灾害加重的主要原因,并提出城市内涝气象服务对策建议。  相似文献   
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