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31.
Monitoring of the ocean environment in southern California, USA, has been conducted by a diverse array of public and private organizations with different motivations, working on a variety of spatial and temporal scales. To create a basis from which to integrate information from these diverse programs, we conducted an inventory of ocean monitoring activities in the Southern California Bight to address the following questions: (1) How much money is being expended annually on marine monitoring programs? (2) Which organizations are conducting the most monitoring? (3) How are resources allocated among the different types of monitoring programs? This inventory focused on programs existing, or those expected to be in existence, for at least 10 years and that were active at any time between 1994 and 1997. For each program identified for inclusion in this study, information was collected on the number of sites, sampling intensity, parameters measured, and methods used. Levels of effort were translated into cost estimates based upon a market survey of local consulting firms. One hundred fourteen marine monitoring programs, conducted by 65 organizations and costing US $31 million annually, were identified. Most of the effort (81 programs, 65% of samples, 70% of costs) was expended by ocean dischargers as part of their compliance with National Pollutant Discharge Elimination System (NPDES) permit requirements. Federal programs (11 programs, 25% of samples, 10% of total expenditures) expended more than state or local government programs. More than one quarter of monitoring expenditures were conducted to measure concentrations and mass of effluent inputs to the ocean. The largest effort expended on receiving water monitoring was for measuring bacteria, followed by sediments, fish/shellfish, water quality, and intertidal habitats. The large level of expenditures by individual agencies has presented opportunities for integrating small, site-specific ocean monitoring programs into regional- and national-scale monitoring and assessment programs.  相似文献   
32.
/ The coastal zone of the Indian Ocean is coming under increasing pressure from human activities. Australia may be one of the few countries in this region that can afford to take adequate conservation measures in the near future. As it also has one of the longest Indian Ocean coastlines, Australia has the opportunity, and responsibility, to make a meaningful contribution to the conservation of Indian Ocean biodiversity. Threatened species, including marine turtles, inshore dolphins, and dugongs are an important component of that biodiversity. The dugong has been exterminated from several areas in the Indian Ocean, and it appears to be particularly threatened by mesh netting andhunting. Its long-term survival may depend on adequate protection in Australia, which contains the largest known Indian Ocean populations. This protection will require, in part, an appropriate system of marine protected areas (MPAs). This paper examines the adequacy of MPAs along Australia's Indian Ocean coast. Dugongs occur in two MPAs in Western Australia. The proposed expansion of the system of marine reserves is based primarily on representative samples of ecosystems from each biogeographic region. It is inadequate because it does not take into account the distribution and relative abundance of threatened species. If the conservation of biodiversity is to be maximized, the system of MPAs should incorporate both representativeness and the needs of threatened species. The level of protection provided by MPAs in Western Australia is low. Under current government policy potentially damaging activities, including commercial fishing, seismic surveys, and oil and gas drilling are permitted in protected areas.KEY WORDS: Marine protected areas; Dugongs; Western Australia; Indian Ocean; Conservation; Biodiversity  相似文献   
33.
Energy economy of salmon aquaculture in the Baltic sea   总被引:1,自引:0,他引:1  
Resource utilization in Atlantic salmon aquaculture in the Baltic Sea was investigated by means of an energy analysis. A comparison was made between cage farming and sea ranching enterprises each with yearly yields of 40 t of Atlantic salmon. A variety of sea ranching options were evaluated, including (a) conventional ranching, (b) ranching employing a delayed release to the sea of young smolts, (c) harvesting salmon both by offshore fishing fleets and as they return to coastal areas, and (d) when offshore fishing is banned, harvesting salmon only as they return to coastal areas where released. Inputs both from natural ecosystems (i.e., fish consumed by ranched salmon while in the sea and raw materials used for producing dry food pellets) and from the economy (i.e., fossil fuels and energy embodied in economic goods and services) were quantified in tonnes for food energy and as direct plus indirect energy cost (embodied energy). The fixed solar energy (estimated as primary production) and the direct and indirect auxiliary energy requirements per unit of fish output were expressed in similar units. Similar quantities of living resources in tonnes per unit of salmon biomass output are required whether the salmon are feeding in the sea or are caged farmed. Cage farming is about 10 times more dependent on auxiliary energies than sea ranching. Sea ranching applying delayed release of smolts is 35–45% more efficient in the use of auxiliary energies than conventional sea ranching and cage farming. Restriction of offshore fishing would make sea ranching 3 to 6.5 times more efficient than cage farming. The fixed solar energy input to Atlantic salmon aquaculture is 4 to 63 times larger than the inputs of auxiliary energy. Thus, cage farming and sea ranching are both heavily dependent on the productivity of natural ecosystems. It is concluded that sustainable development of the aquaculture industry must be founded on ecologically integrated technologies which utilize the free production in marine ecosystems without exhausting or damaging the marine environment.  相似文献   
34.
As large numbers of ships either take in ballast from or discharge their ballast into the Mumbai Harbor region, it is pertinent to quantify microorganisms of health concerns and suggest on the suitability of water for ballasting purposes. To meet with this main aim, a selected set of general and pathogenic bacterial groups and their seasonal variations were studied from the Mumbai Harbor area. Sampling was carried out during postmonsoon (November 2001), pre-monsoon (April 2002) and monsoon (October 2002) periods. We quantified total coliforms and eight other groups of known human pathogenic bacteria from water, sediment, marine plant and animal samples collected in and around Mumbai Harbor. When compared with similar studies from other parts/harbors of the world, the Mumbai Harbor area has over 100-times higher levels of coliforms. The serotypes of Escherichia coli O157 and Shigella-Alkaligens Dispar group were abundant throughout the year. Even Vibrio cholerae, V. parahaemolyticus, Salmonella spp., campylobacters and aeromonads were present in large numbers. This comprehensive study, conducted with a view to quantify these bacterial groups and to evaluate the suitability of these waters for ballasting purposes, clearly suggests that both ballasting and deballasting be avoided in this region and alternative procedures should be developed for treating/handling ballast water.  相似文献   
35.
Synoptic data on concentrations of sediment-associated chemical contaminants and benthic macroinfaunal community structure were collected from 1,389 stations in estuaries along the U.S. Atlantic and Gulf of Mexico coasts as part of the nationwide Environmental Monitoring and Assessment Program (EMAP). These data were used to develop an empirical framework for evaluating risks of benthic community-level effects within different ranges of sediment contamination from mixtures of multiple chemicals present at varying concentrations. Sediment contamination was expressed as the mean ratio of individual chemical concentrations relative to corresponding sediment quality guidelines (SQGs), including Effects Range-Median (ERM) and Probable Effects Level (PEL) values. Benthic condition was assessed using diagnostic, multi-metric indices developed for each of three EMAP provinces (Virginian, Carolinian, and Louisianian). Cumulative percentages of stations with a degraded benthic community were plotted against ascending values of the mean ERM and PEL quotients. Based on the observed relationships, mean SQG quotients were divided into four ranges corresponding to either a low, moderate, high, or very high incidence of degraded benthic condition. Results showed that condition of the ambient benthic community provides a reliable and sensitive indicator for evaluating the biological significance of sediment-associated stressors. Mean SQG quotients marking the beginning of the contaminant range associated with the highest incidence of benthic impacts (73–100% of samples, depending on the province and type of SQG) were well below those linked to high risks of sediment toxicity as determined by short-term toxicity tests with single species. Measures of the ambient benthic community reflect the sensitivities of multiple species and life stages to persistent exposures under actual field conditions. Similar results were obtained with preliminary data from the west coast (Puget Sound).  相似文献   
36.
南半球气候变暖对西北太平洋热带气旋的影响   总被引:7,自引:0,他引:7  
在分析南半球地面气温序列和西北太平洋热带气旋序列的基础上,讨论了南半球气候变暖对西北太平洋上热带气旋的影响和可能的机制。结果表明,随着南半球气候变暖,西北太平洋上热带气旋的频数减少,强度减弱;同时,随着南半球气候变暖,西北太平洋上强台风的频数将减少,最大中心风速将减弱。一种可能的机制是由于从南半球侵入西北太平洋的冷空气随着南半球气候的变暖而减弱。  相似文献   
37.
Non‐governmental organisations (NGOs) are widely believed to raise their flag in humanitarian hotspots with a strong media presence in order to attract higher private donations. We assess this hypothesis by comparing the changes in donations between US‐based NGOs with and without aid operations in the four countries most affected by the tsunami in the Indian Ocean in 2004. Simple before‐after comparisons tend to support the hypothesis that ‘flying the flag’ helps attract higher private donations. However, performing a difference‐in‐difference‐in‐differences (DDD) approach, we find only weak indications that private donors systematically and strongly preferred NGOs with operations in the region. Extended specifications of the baseline regressions reveal that our major findings are robust. NGO heterogeneity matters in some respects, but the DDD results hold when accounting for proxies of the NGOs’ reputation and experience.  相似文献   
38.
The Arctic Ocean is undergoing rapid change: sea ice is being lost, waters are warming, coastlines are eroding, species are moving into new areas, and more. This paper explores the many ways that a changing Arctic Ocean affects societies in the Arctic and around the world. In the Arctic, Indigenous Peoples are again seeing their food security threatened and cultural continuity in danger of disruption. Resource development is increasing as is interest in tourism and possibilities for trans-Arctic maritime trade, creating new opportunities and also new stresses. Beyond the Arctic, changes in sea ice affect mid-latitude weather, and Arctic economic opportunities may re-shape commodities and transportation markets. Rising interest in the Arctic is also raising geopolitical tensions about the region. What happens next depends in large part on the choices made within and beyond the Arctic concerning global climate change and industrial policies and Arctic ecosystems and cultures.  相似文献   
39.
Dimethyl sulphide (DMS) and carbon monoxide (CO) are climate-relevant trace gases that play key roles in the radiative budget of the Arctic atmosphere. Under global warming, Arctic sea ice retreats at an unprecedented rate, altering light penetration and biological communities, and potentially affect DMS and CO cycling in the Arctic Ocean. This could have socio-economic implications in and beyond the Arctic region. However, little is known about CO production pathways and emissions in this region and the future development of DMS and CO cycling. Here we summarize the current understanding and assess potential future changes of DMS and CO cycling in relation to changes in sea ice coverage, light penetration, bacterial and microalgal communities, pH and physical properties. We suggest that production of DMS and CO might increase with ice melting, increasing light availability and shifting phytoplankton community. Among others, policy measures should facilitate large-scale process studies, coordinated long term observations and modelling efforts to improve our current understanding of the cycling and emissions of DMS and CO in the Arctic Ocean and of global consequences.  相似文献   
40.
The Arctic marine ecosystem is shaped by the seasonality of the solar cycle, spanning from 24-h light at the sea surface in summer to 24-h darkness in winter. The amount of light available for under-ice ecosystems is the result of different physical and biological processes that affect its path through atmosphere, snow, sea ice and water. In this article, we review the present state of knowledge of the abiotic (clouds, sea ice, snow, suspended matter) and biotic (sea ice algae and phytoplankton) controls on the underwater light field. We focus on how the available light affects the seasonal cycle of primary production (sympagic and pelagic) and discuss the sensitivity of ecosystems to changes in the light field based on model simulations. Lastly, we discuss predicted future changes in under-ice light as a consequence of climate change and their potential ecological implications, with the aim of providing a guide for future research.  相似文献   
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