全文获取类型
收费全文 | 2213篇 |
免费 | 174篇 |
国内免费 | 60篇 |
专业分类
安全科学 | 125篇 |
废物处理 | 17篇 |
环保管理 | 1041篇 |
综合类 | 577篇 |
基础理论 | 365篇 |
环境理论 | 2篇 |
污染及防治 | 42篇 |
评价与监测 | 57篇 |
社会与环境 | 129篇 |
灾害及防治 | 92篇 |
出版年
2023年 | 18篇 |
2022年 | 37篇 |
2021年 | 48篇 |
2020年 | 51篇 |
2019年 | 49篇 |
2018年 | 59篇 |
2017年 | 84篇 |
2016年 | 93篇 |
2015年 | 92篇 |
2014年 | 77篇 |
2013年 | 120篇 |
2012年 | 79篇 |
2011年 | 130篇 |
2010年 | 89篇 |
2009年 | 105篇 |
2008年 | 97篇 |
2007年 | 113篇 |
2006年 | 107篇 |
2005年 | 82篇 |
2004年 | 70篇 |
2003年 | 75篇 |
2002年 | 51篇 |
2001年 | 56篇 |
2000年 | 53篇 |
1999年 | 68篇 |
1998年 | 41篇 |
1997年 | 37篇 |
1996年 | 42篇 |
1995年 | 40篇 |
1994年 | 27篇 |
1993年 | 17篇 |
1992年 | 22篇 |
1991年 | 18篇 |
1990年 | 12篇 |
1989年 | 12篇 |
1988年 | 13篇 |
1987年 | 21篇 |
1986年 | 22篇 |
1985年 | 24篇 |
1984年 | 22篇 |
1983年 | 13篇 |
1982年 | 12篇 |
1980年 | 15篇 |
1979年 | 17篇 |
1978年 | 20篇 |
1977年 | 14篇 |
1975年 | 10篇 |
1973年 | 16篇 |
1972年 | 14篇 |
1971年 | 16篇 |
排序方式: 共有2447条查询结果,搜索用时 15 毫秒
131.
Zhao Ma Dennis R. Becker Michael A. Kilgore 《Journal of Environmental Planning and Management》2009,52(8):1035-1051
Following the intent of the National Environmental Policy Act of 1969, many states have adopted policies and procedures directing state agencies and local government units to evaluate the potential environmental impacts of development projects prior to their undertaking. In contrast to a rich literature on federal requirements, current understanding of state environmental review is narrowly focused and outdated. This paper seeks to provide information on the landscape of state environmental review policy frameworks. The paper identifies 37 states with formal environmental review requirements through a document review of state statutes, administrative rules and agency-prepared materials, and confirms this finding through a survey of state administrators. A two-tier classification is used to distinguish states based on the approach taken to address environmental review needs and the scope and depth of relevant policies and procedures implemented. This paper also provides a discussion of policy and programme attributes that may contribute to effective practice, and of the potential for adopting relevant legislation in states where environmental review is currently lacking. 相似文献
132.
This paper develops a methodology of proper scale analysis for regional industry development, which can be used in industry planning with the consideration of regional resource capacities. In the face of different data sources and even data scarcity, alternative methods based on linear programming and quadratic programming algorithms for calculating the resource intensity factors are designed. Based on the empirical study of industrialization, initial scenarios of industry development were set. Using HSY algorithm, sensitive industries that may cause exceeding regional resource capacity can be identified, and the risk of exceeding can be predicted and expressed in probability. Furthermore, a proper scale range can be designed for these sensitive industries according to resource capacity. Taking the case of Dalian city in China, this paper estimated the regional urban development plan, various resources capacities were studied, and land resources were estimated to be the most critical resource for the city. The land resource depletion intensities of different industries are calculated by quadratic programming algorithm. Under the constraint of 427.56 km2 available industrial land resources, the electronic and power industries have the most significant impact on total land use, if the scale of power industry exceeds 1.27 billion USD, the probability of land resource capacity breakthrough will be 50%. 相似文献
133.
134.
Charles A. Young Marisa I. Escobar‐Arias Martha Fernandes Brian Joyce Michael Kiparsky Jeffrey F. Mount Vishal K. Mehta David Purkey Joshua H. Viers David Yates 《Journal of the American Water Resources Association》2009,45(6):1409-1423
Young, Charles A., Marisa I. Escobar‐Arias, Martha Fernandes, Brian Joyce, Michael Kiparsky, Jeffrey F. Mount, Vishal K. Mehta, David Purkey, Joshua H. Viers, and David Yates, 2009. Modeling the Hydrology of Climate Change in California’s Sierra Nevada for Subwatershed Scale Adaptation. Journal of the American Water Resources Association (JAWRA) 45(6):1409‐1423. Abstract: The rainfall‐runoff model presented in this study represents the hydrology of 15 major watersheds of the Sierra Nevada in California as the backbone of a planning tool for water resources analysis including climate change studies. Our model implementation documents potential changes in hydrologic metrics such as snowpack and the initiation of snowmelt at a finer resolution than previous studies, in accordance with the needs of watershed‐level planning decisions. Calibration was performed with a sequence of steps focusing sequentially on parameters of land cover, snow accumulation and melt, and water capacity and hydraulic conductivity of soil horizons. An assessment of the calibrated streamflows using goodness of fit statistics indicate that the model robustly represents major features of weekly average flows of the historical 1980‐2001 time series. Runs of the model for climate warming scenarios with fixed increases of 2°C, 4°C, and 6°C for the spatial domain were used to analyze changes in snow accumulation and runoff timing. The results indicated a reduction in snowmelt volume that was largest in the 1,750‐2,750 m elevation range. In addition, the runoff center of mass shifted to earlier dates and this shift was non‐uniformly distributed throughout the Sierra Nevada. Because the hydrologic model presented here is nested within a water resources planning system, future research can focus on the management and adaptation of the water resources system in the context of climate change. 相似文献
135.
Kristin Floress Jean C. Mangun Mae A. Davenport Karl W.J. Williard 《Journal of the American Water Resources Association》2009,45(6):1352-1360
Floress, Kristin, Jean C. Mangun, Mae A. Davenport, and Karl W.J. Williard, 2009. Constraints to Watershed Planning: Group Structure and Process. Journal of the American Water Resources Association (JAWRA) 45(6):1352‐1360. Abstract: The roles that agencies and other partners play in collaborative watershed management are not always clearly identified. Key factors contributing to group‐level outcomes in watershed groups include both structural and procedural elements. Structural elements include membership systems, project partners, and funding, while procedural elements include leadership, shared vision, and mission development. The current research reports on a case study conducted with a Midwestern watershed group that received Clean Water Act Section 319 funds to undertake a watershed planning process. Data come from focus groups, interviews, public comments, and meeting observation, and were analyzed using grounded theory. Findings of this study indicate that homogenous skill set, discord over group and partner roles, and failed problem identification contributed to the organizational inertia experienced by the watershed group. Implications of this research for groups receiving 319 funds are provided. 相似文献
136.
Kelli Larson 《Journal of the American Water Resources Association》2009,45(4):879-893
Abstract: Surface water resources in urban areas serve multiple functions ranging from recreation to wildlife habitat. As a result, diverse values influence people’s views about resource protection, potentially leading to conflicting interests. In metropolitan Portland, Oregon, natural resource planning has recently focused on habitat restoration as well as stormwater and pollution mitigation, especially through the protection of riparian areas. Due to opposition over proposed regulations in the study region, this research examines public attitudes about an array of resource management efforts. The primary research question is: what is the extent of positive–negative attitudes about water resource protection, and what theoretical dimensions underlie diverse judgments? After empirical survey results are presented, I outline a conceptual approach for future assessments of environmental attitudes while highlighting important value‐based dimensions of judgments. Although flexible, the framework allows broad comparisons to advance knowledge about the social acceptability of varied water resource management approaches across diverse places and contexts. 相似文献
137.
基于化工园区整体风险量分析的安全规划研究 总被引:3,自引:2,他引:1
通过对园区安全容量和危险量的分析,得到园区整体的风险评估值;提出并定义园区危安比最大临界点,用其反映园区的最大可接受风险量;运用"二八法则",确定危安比上限;当危安比在3种不同值域区间下,对应的园区安全规划的重点不同;从园区整个生命周期考虑,提出包含各个阶段的园区安全规划主要内容。 相似文献
138.
对杭州市部分自然灾害应急预案完备性评价的实证研究 总被引:2,自引:0,他引:2
采用故障树分析方法,从灾害的预防与应急准备、监测与预警、应急响应、后期处理4个方面,对2008年以前杭州市编制的部分自然灾害应急预案的完备度进行评价。结果表明:各类自然灾害应急预案的完备度不一,一些应急预案具有较高的完备度,而一些应急预案完备度偏低;大部分应急预案在灾害监测与预警方面具有较高的完备度,部分应急预案在灾害预防与应急准备、灾害后期处理完备度偏低;各应急预案中志愿者队伍的建设、灾害风险评价、应急人员的安全防护、灾后的保险理赔、重要设施的安全防护、启动应急避难场所等基本事件的缺失率较高,反映了部分应急预案编制过程中灾害全过程管理理念的缺失。 相似文献
139.
我国城市灾害风险应对现状及对策研究 总被引:5,自引:4,他引:1
阐述了城市灾害的分类;从城市灾害预防与控制,应急反应与救援等方面分析我国在城市灾害风险控制与应对上的不足;提出8个方面的对策。该对策研究包括:建立城市安全规划、风险防范和危机管理法律体系;实施城市防灾减灾规划并融入城市规划中;完善城市灾害风险决策支持系统和信息管理系统;实行安全规划风险评价机制;加快防灾减灾综合管理机构建设;建立科学、完善的应急救援体系;加强安全教育和防灾减灾宣传;加强城市安全科学研究与交流。该研究结果对如何提高我国城市灾害风险预防与控制能力及应急救援水平具有重要的借鉴和指导作用。 相似文献
140.
Monitoring urban growth and detecting land-cover changes on the Istanbul metropolitan area 总被引:1,自引:0,他引:1
Istanbul is the most populated city of Turkey with a population of around 10.58 M (2000) living on around 5,750 km2. In 1980, the population was only 4.7 M and then it has been more than doubled in only two decades. The population has been
increasing as a result of mass immigration. An urbanization process continues and it causes serious increases in urban areas
while decreasing the amount of green areas. This rapid, uncontrolled, and illegal urbanization accompanied by insufficient
infrastructure has caused degradation of forest and barren lands in the metropolitan area, especially through the last two
decades. The watershed basins inside the metropolitan area and the transportation network have accelerated the land-cover
changes, which have negative impacts on water quality of the basins. Monitoring urban growth and land cover change will enable
better management of this complex urban area by the Greater Istanbul Metropolitan Municipality (GIMM). A temporal assessment
of land-cover changes of Istanbul has been documented in this study. The study mainly focuses on the acquisition and analysis
of Landsat TM and Landsat GeoCover LC satellite images reflecting the significant land-cover changes between the years of
1990 and 2005. Raster data were converted to vector data and used in Geographic Information Systems (GIS). A database was
created for Istanbul metropolitan area to plan, manage, and utilize statistical attribute data covering population, water,
forest, industry, and topographic position. Consequently an overlay analysis was carried out and land use/cover changes through
years have been detected for the case study area. The capability of Landsat images in determining the alterations in the macro
form of the city are also discussed. 相似文献