全文获取类型
收费全文 | 693篇 |
免费 | 10篇 |
国内免费 | 11篇 |
专业分类
安全科学 | 47篇 |
废物处理 | 7篇 |
环保管理 | 192篇 |
综合类 | 111篇 |
基础理论 | 239篇 |
环境理论 | 4篇 |
污染及防治 | 39篇 |
评价与监测 | 21篇 |
社会与环境 | 29篇 |
灾害及防治 | 25篇 |
出版年
2023年 | 4篇 |
2022年 | 6篇 |
2021年 | 14篇 |
2020年 | 6篇 |
2019年 | 22篇 |
2018年 | 14篇 |
2017年 | 16篇 |
2016年 | 32篇 |
2015年 | 19篇 |
2014年 | 22篇 |
2013年 | 31篇 |
2012年 | 11篇 |
2011年 | 31篇 |
2010年 | 19篇 |
2009年 | 64篇 |
2008年 | 54篇 |
2007年 | 57篇 |
2006年 | 55篇 |
2005年 | 28篇 |
2004年 | 27篇 |
2003年 | 17篇 |
2002年 | 13篇 |
2001年 | 11篇 |
2000年 | 21篇 |
1999年 | 17篇 |
1998年 | 13篇 |
1997年 | 11篇 |
1996年 | 11篇 |
1995年 | 11篇 |
1994年 | 10篇 |
1993年 | 8篇 |
1992年 | 5篇 |
1991年 | 3篇 |
1990年 | 4篇 |
1989年 | 1篇 |
1987年 | 3篇 |
1986年 | 4篇 |
1985年 | 1篇 |
1984年 | 4篇 |
1983年 | 2篇 |
1980年 | 2篇 |
1979年 | 3篇 |
1978年 | 2篇 |
1977年 | 2篇 |
1974年 | 1篇 |
1973年 | 2篇 |
排序方式: 共有714条查询结果,搜索用时 718 毫秒
471.
中国经济系统地震易损性分析 总被引:5,自引:3,他引:5
本文分析了地震对经济系统功能的破坏。在现有数据的基础上建立了一个经济模型,用于定量分析地震对经济的破坏。并进一步提出了一个动态区域经济模型的原理和基本结构,当数据条件具备即可建立模型。这样一个动态模型可确切地描述地震对经济系统的破坏及破坏后的恢复过程。 相似文献
472.
200 years of sustainability in forestry: Lessons from history 总被引:4,自引:0,他引:4
K. Freerk Wiersum 《Environmental management》1995,19(3):321-329
Since the end of the 1980s the concept of sustainable development has gained general acceptance, but much uncertainty still
exists on how to operationalize this concept. In forestry the concept of sustainability has been an accepted principle since
the 18th century. The experiences with its application in forestry may contribute towards obtaining a better insight into
the implications and operational significance of the concept of sustainability. This article describes the history of sustainability
in forestry, including the various social values on which its interpretation has been based. The original principle of sustained
yield has gradually been broadened to a more inclusive principle of sustainable forest management. The dynamics in social
valuation of forest resources resulted in various attempts at practical operationalization of the principle. Notwithstanding
200 years of efforts to operationalize the concept of sustainability, its exact application in forestry remains troublesome.
Three lessons are drawn: (1) the need to recognize the different nature of ecological limits and social dynamics, (2) the
role of dynamic social values with respect to forest resources, and (3) the significance of operational experiences in trying
to attain sustainability within a concrete context. 相似文献
473.
Mark Zeitoun Azza Dirar Asim El Moghraby Mohammad Jalal Hashim 《Local Environment》2019,24(2):129-145
ABSTRACTThis paper applies a “justice” lens to the struggle of the people displaced by the Merowe Dam in northern Sudan. Application of distributive, procedural, and representational aspects of justice exposes the dissatisfaction of the affected people with the government’s offer and execution of compensation. Consideration of social justice and the utility of norms in trans-national activism brings into sharp focus the difference in interests, and abilities of the many actors involved, and highlights the government’s tactics to divide the communities, and the social divisions sown. As the struggle develops, justice claims are seen to change towards less material issues, suggesting that an expanded and dynamic conception of justice is more helpful than narrow or time-bound conceptions. The findings are of relevance to communities facing possible displacement from dams planned nearby, not least of all for the insight provided on the effectiveness of different tactics in the struggle. 相似文献
474.
M. Zemamou A. Toumi K. Mrigua Y. Lahlou M. Aggour 《International Journal of Green Energy》2020,17(11):652-665
ABSTRACT Advanced wind turbine designs and technologies have been evolved to take advantage of wind energy. Despite the significant progress already attained, the need for a dependable wind energy converter particularly devoted to small-scale applications remains a challenging issue. Due to its design simplicity, Savonius wind turbine is the most suitable candidate for such applications. It operates at low wind speed, with the necessary starting capacity and insensitivity to wind directions. Moreover, in the literature related to wind energy, the Savonius rotor is known for its low performance compared to other types of wind turbines. In this paper, we present a study into the utilization of Bézier curves and transient computational fluid dynamics (CFD) to optimize the conventional Savonius blade design. The k-ω SST turbulence model is employed to perform a series of CFD simulations in order to assess the power coefficient of each generated design. A validation of optimization results using the Taguchi method was carried out. The comparative analysis of the torque and power coefficients shows a significant increase in the power coefficient (Cp). The optimal Cp is 0.35 and is 29% higher than the conventional Savoniu wind turbine (SWT). Subsequently, the effectiveness of the innovative geometry is proved by improved pressure and velocity distributions around blades of novel design. 相似文献
475.
Robert B. McKusick Richard M. Adams J. Herbert Snyder 《Journal of the American Water Resources Association》1977,13(3):489-498
ABSTRACT: This paper evolved from a concern that water resource administrators and planners do not have a consistent definition of the value of goods and services of outputs from projects and programs. A more flexible approach to planning and evaluation is presented that recognizes the interaction of production and consumption through the use of commodity demand curves. Use of the concept of consumer surplus permits measurement of the differential impacts on producers' and consumers' welfare. Quadratic programming is suggested as a consistent means of quantifying these differential impacts. 相似文献
476.
Hugh Clout 《Journal of Environmental Planning and Management》1987,30(2):70-78
Serious social and environmental problems are encountered on many of the large post‐war estates of blocks of social housing (grands ensembles) surrounding French cities, as well as in many inner‐city districts. In 1981 the new Socialist administration set up a National Commission to foster grass‐roots schemes in order to improve housing and to attempt to tackle both the expressions and the causes of social problems. The resulting neighbourhood programme represents an innovative dialogue between the central State, the regions, local authorities and residents’ groups. Examination of a sample of projects from the provinces (Romans, Dreux, Les Minguettes) and the Paris region confirms that progress has been made by improving housing, open spaces and community facilities. Formidable problems of poverty, unemployment and racism remain on many estates. 相似文献
477.
Lester W. Milbrath 《Environmental management》1985,9(2):161-172
The beliefs of Americans about the proper relationship between humans and their environment were profoundly affected by waves of immigration from Europe. Immigrants valued ownership of land, individuality, freedom, domination of nature, and technological development. These themes remain strong today as centerpieces of the American dominant social paradigm (DSP).That DSP has been reexamined and found wanting by an increasing proportion of Americans. This departure from the old DSP has progressed further among the public than among the elite who have a greater stake in preserving the status quo. Environmentalists constitute a vanguard trying to lead the people to a new, more environmentally oriented social paradigm. The beliefs of the old DSP and the new environmental paradigm (NEP) are contrasted in Table 2. Briefly, the NEP advocates stress love of nature rather than domination of it; compassion for other peoples, future generations, and other species; planning to avoid risk; limits to growth; fundamental social change; and a new structuring of politics.These two worldviews are likely to be in vigorous conflict for several decades in the USA. Social learning, spurred by deterioration of the old ways, is likely to lead Americans to a new perspective on their relationship to nature.With the advice and assistance of Barbara V. Fisher. 相似文献
478.
Herbert C. Preul Constantine N. Papadakis 《Journal of the American Water Resources Association》1973,9(2):291-300
ABSTRACT A synthetic storm rainfall hyetograph for a one-year design frequency is derived from the one-year intensity-duration curve developed for Cincinnati, Ohio. Detailed rainfall data for a three-year period were collected from three raingages triangulating the Bloody Run Sewer Watershed, an urban drainage areas of 2380 acres'in Cincinnati, Ohio. The advancement of the synthetic storm pattern is obtained from an analysis of the antecedent precipitation immediately preceding the maximum period of three selected durations. Rains which produced excessive runoff at least for some duration were considered only. The same approach can be used for other design frequencies. The purpose of this study is to provide synthetic storm hyetographs to be used as input in deterministic mathematical models simulating urban storm water runoff for the design, analysis and possible surcharge prediction of sewer systems. 相似文献
479.
Achieving resource sustainability, particularly in the coastal zone, is complicated by a variety of interdependencies and trade-offs between economic, social, and ecological variables. Although trade-offs between each of these variables are important, this paper emphasizes the social components of resource management. In this regard a distinction is made between individual and cooperative choices. Individual choices frequently are made from a shortterm, self-interested perspective, whereas cooperative choices are made from a long-term, community and resource-sustainability perspective. Typically, when presented with a spectrum of resource management decisions, individuals have a tendency to act in a self-interested manner. Thus, cooperative benefits, such as reduced conflict and improved resource certainty, are not realized. An overview of selected aspects of social dilemma theory suggests that socially cooperative choice outcomes are attainable in coastal zone management by integrating structural and behavioral solutions in resource use decision making. Three barriers to successful integration of structural and behavioral solutions are identified as self-interest, mistrust, and variable perceptions of resource amenities. Examples from coastal zone management indicate that these barriers may be overcome using approaches such as scopereduction, co-management, community education, and local participation. The paper also provides comment on the potential benefits of integrating structural and behavioral solutions in international coastal zone management efforts. 相似文献
480.
亚热带典型小流域总氮最大日负荷(TMDL)及影响因子研究——以金井河流域为例 总被引:5,自引:0,他引:5
本研究以亚热带红壤丘陵区为研究区域,选取10个典型小流域,根据土地利用和畜禽养殖密度分为4种类型(森林、森林-种植、养殖和种植-养殖小流域),并基于近3年小流域把口站的原位观测数据,采用负荷历时曲线模型(LDC)计算了不同类型小流域水体总氮(TN)的最大日负荷(TMDL),运用灰度分析法定量研究了不同流量阶段小流域主要因子对TN负荷消减率的影响.结果表明,小流域TN负荷特征与流域类型密切相关,10个小流域TN年均负荷为739.0~2798.4 kg·km-2·a-1,由小到大依次为森林、森林-种植、养殖、种植-养殖小流域,其中,养殖、种植-养殖小流域水质整体超标严重,且应针对中、低流量条件下(秋、冬季节)负荷进行消减,而森林-种植小流域TN负荷超标情况略好,但高流量阶段(春、夏)超标率过高.灰度分析结果表明,TN负荷消减率在高、中流量阶段下主要受农田面积比例影响,而低流量阶段受畜禽密度影响.农田面积比例对高、中流量段TN消减率影响显著,而畜禽养殖密度在低流量段具有更大影响,小流域景观越破碎、类型越丰富、斑块分布越零散、形状越复杂,TN负荷通量则越大. 相似文献