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921.
Research on the development of the interrelationship between society and environment is crucial for the understanding of contemporary
landscapes. The West-Estonian archipelago provides an opportunity for such investigations because of its small size, landscape
diversity, and well-defined economic activities.
The contemporary landscapes of the islands reflect environmental changes resulting from centuries of human activity. This
paper describes both natural and human factors in the change in landscape of small Estonian islands during the last centuries.
During the period 1850–1940, human activity diversified the landscape structure. During World War II, with the establishment
of Soviet rule, the islets were depopulated; their landscape became more uniform and lost their economic and ecological vitality.
The re-establishment of private ownership of land and a market economy is predicted to result in positive changes in the landscape
of the islets. 相似文献
922.
The rise of the postwar environmental movement is rooted in the development of ecological consciousness within intellectual circles as well as the general public. Though many commentators cite the 1960s as the focal point of the new environmentalism, the ecological ethic had actually evolved by the 1930s in the writings and speeches of both scientists and public commentators. Agricultural conservationists led the way in broadcasting the message of ecology. Friends of the Land, an agriculturally-oriented conservation organization formed in 1940 and active through the 1950s, is an interesting example of how the agricultural community was an integral component in the rise of environmentalism. While Friends of the Land flourished only for a brief period, its goals and the ideas that the group represented illustrate how the ecological ethic was burgeoning by the early-1950s. Furthermore, the history of Friends of the Land is an important chapter in the ongoing quest for ecological agriculture and societal permanence. 相似文献
923.
A broad and objective perspective of ecological and socioenomic knowledge is required to underlie a scientific approach to
the problems of terrestrial restoration ecology. Uncertainty associated with limited scientific knowledge highlights the crucial
importance of the interaction between science and policy in weighing ecological restoration alternatives in relation to other
management options. In this paper, we provide a pragmatic definition for restoration ecology that is suitable for extensive
terrestrial applications and present a decision framework to help organize and clarify different phases of the decision process
as it is related to ecological restoration. We argue that restoration planning should include a wider spectrum of participants
and decisions than have traditionally been employed. 相似文献
924.
Joanne Heckman 《Environmental management》1985,9(2):141-149
The Cape Verde Islands originally supported a limited island ecology which, since the arrival of settlers 500 years ago, has been steadily altered or destroyed. Today, deforestation and overfarming, combined with the natural conditions of aridity and strong winds, have rendered the islands barren and eroded. The current government of the Republic of Cape Verde is attempting to alter traditional attitudes and customs of environmental neglect and mismanagement, while at the same time striving to restore or create self-sustaining ecosystems. The introduction of plants, animals, and physical structures enhancing soil and water conservation may create a more viable total ecosystem than existed before humans arrived. 相似文献
925.
Fred D. Theurer Ivan Lines Terry Nelson 《Journal of the American Water Resources Association》1985,21(1):53-64
ABSTRACT: This analysis relates physical-process, ecological, and economic models to: (1) analyze the instream water temperatures with respect to existing and proposed riparian vegetation under natural conditions; (2) use these water temperatures to determine salmon and steel-head fish populations that were based upon actual field count and known temperature preference data; and (3) determine the economic worth based upon the estimated carrying capacity of the river, the estimated number of return spawners, and the economic value of commercially caught and sport-caught salmon and steelhead. The economic evaluations are in accordance with procedures outlined by the U.S. Water Resources Council (1983). 相似文献
926.
Monica Goigel Turner 《Environmental management》1987,11(2):237-247
Land use since 1935 was quantified for Georgia, USA, and for a sample of 20 counties from the major physiographic regions within the state. Statistical data on crop production, pasture productivity, and forest growth were used to estimate net primary production. Appropriate harvest indices (ratio of crop yield to total plant production) were used to correct crop yield data for different decades. Net primary production (NPP) of the Georgia landscape increased from 2.5 to 6.4 tonnes/ha from 1935 to 1982, but varied considerably among land uses and physiographic regions. NPP in the piedmont and mountains reached a plateau between 1960 and 1982, but the upper and lower coastal plains showed a continued linear increase in NPP. In all regions, NPP rose most between 1960 and 1982, coinciding with increases in inputs such as fertilizer and irrigation. Natural ecosystem NPP for Georgia is approximately 16–18 tonnes/ha, and the estimated actual NPP is thus considerably less than the potential. Spatial and temporal patterns of NPP may be a useful basis for evaluating the biological performance of a landscape. 相似文献
927.
Since the beginning of the 1960s, mass tourism has been the most important menace to the environmental stability of fragile
and vulnerable Mediterranean microinsular systems. The socioeconomic changes introduced by tourism have produced important
variations in the use of resources, including land. The result usually has been an increase in the level of artificiality
of the territory, particularly in coastal areas. The intensity and frequency of change in the use of resources and the induced
changes in the level of artificiality may be used as an estimation of environmental stability. The northern area of Formentera,
Balearic islands, Spain, being the most environmentally important area of the island and simultaneously the most threatened
by mass tourism development, has been chosen as a study case. Forty types of vegetation and land use have been estimated and
mapped in the area. The stability level of each land use type has been estimated, before and after the development of tourism,
and the main environmental processes have been identified. An attempt is made to predict some future trends and their variations. 相似文献
928.
B. De Martis M. A. de Miranda Restivo A. Mocci Demartis E. Serra 《Environmental management》1992,16(3):381-388
Capoterra Pond in southern Sardinia is described and analyzed with respect to its morphological, meteorological, physical
and chemical characteristics, and its zoobenthic, zooplankton, and phytoplankton biocenoses. The birdlife, flora, and riparian
associations of vegetation are studied in order to draw international attention to the importance of this lagoon, the precariousness
of its ecosystem, the seriousness of current attempts to destabilize it, and the need to encourage the Sardinian authorities
to initiate conservation measures, especially as rare birds have found their niches there. 相似文献
929.
Agriculture and medicine palpably manifest a culture's world view. Correspondingly, changes in agriculture and medicine may be barometers of change in a culture's overall outlook. Conventional industrial agriculture and modern surgical/chemical medicine clearly express the Newtonian mechanical model of nature. The modern classical world view represents nature to be an externally related, atomic, reductive, material, and mechanical aggregate. Modern medicine, correspondingly, treats the body as an elaborate mechanism and industrial agriculture regards soil as a substratum for monocultures assembled from fossil fuels, synthetic fertilizers, and chemical pesticides. The nascent agroecology and wellness movements each express and reflect the new paradigm variously emerging from ecology and quantum physics. Ecology and the new physics, each in its own way, represent nature to be an internally related, systemic, integrated, organic whole. Agroecology translates this abstract new vision into a concrete agricultural vocabulary: The farmstead is regarded as an artificial ecosystem with a multiplicity of diverse plant and animal constituents interacting with one another and with environing natural ecosystems in complex and mutually supporting ways. 相似文献
930.
本文描述了海洋高技术的兴起与进展、海洋采矿对生态环境影响的案例分析。60年代以来,海洋高技术最重要的成就是深海采矿,根据当前发展动态看,深海石油和采矿技术仍是海洋高技术的主要方向,而海洋生物技术也是最有前景的高技术领域之一。对油船触礁造成的漏油事故案例分析指出海洋高技术对海洋生态环境的影响主要表现如下:1.对海洋生物资源的危害。首先,在油污染事件的短期内大量海鸟和海兽被杀死;其次,长期累积在经济鱼类内的有害物质通过食物链进入人体而对人体健康产生危害。2.对海滨环境的影响。如破坏海滨浴场水质。为了避免各种海洋高技术对海洋生态环境的影响,介绍了几点政策建议。 相似文献