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141.
An increasing number of studies indicate that marine mammals and some seabirds are exposed to organotins. However, results from northern and Arctic areas are few. Here results from analysis of tributyltin (TBT), dibutyltin (DBT), monobutyltin (MBT), triphenyltin (TPhT), diphenyltin (DPhT) and monophenyltin (MPhT) in harbour porpoise (Phocoena phocoena), common seal (Phoca vitulina), ringed seal (Phoca hispida) and glaucous gull (Larus hyperboreus) from Norwegian territory are presented. Relatively high concentrations of DBT, TBT and MBT were observed in muscle, kidney and liver from harbour porpoises caught in northern Norway in 1988, just before restrictions on the use of tributyltin (TBT)(mainly on small boats) were introduced in several European countries. The concentrations in harbour porpoise muscle tissue were reduced significantly 11 years later, possibly as a result of the introduced restrictions. Considerably lower concentrations of butyltins were observed in the seals compared to porpoises. The lowest levels of organotins were found in ringed seals from Spitsbergen, where only traces of dibutyltin (DBT) and monobutyltin (MBT) were observed. Traces of DBT and MBT were also found in some individual glaucous gulls from Bear Island. The sum of the degradation products MBT and DBT in liver samples from all analysed species were generally higher than TBT itself. Triphenyltin (TPhT) was observed in all porpoise samples and in livers of common seals. Also the sum of the degradation products MPhT and DPhT in liver samples from porpoise and common seals were higher than TPhT. No traces of phenyltins were found in ringed seals from Spitsbergen or in glaucous gulls from Bear Island. The limited data available indicate low to moderate exposure to organotins in northern areas (Spitsbergen and Bear Island). Marine mammals are however more exposed further south along the Norwegian Coast.  相似文献   
142.
Since its introduction into Danish planning in 1989, Environmental Impact Assessment (EIA) has been widely discussed. At the centre of the debate the question has been whether EIA has actually offered anything new and there has been a great deal of scepticism about the efficacy of the instrument. Although, in principle EIA offers a holistic and proactive methodology, it does not seem to lead to a more holistic and proactive regulation which covers more ground than traditional planning and environmental regulation. In an evaluation of Danish experiences, this study has looked more closely at the effects of EIA. Three types of effects on projects have been examined: changes occurring prior to the formal application; changes during the EIA process; and the mitigation measures that are demanded of projects. The general conclusion is that EIA does generate a significant number of changes to projects. In approximately half of the cases studied, modifications are made prior to the formal application. During the formal EIA process, modifications were made in more than 90% of the cases. However, most of these could be considered as minor. EIA is characterized by being based upon a broad concept of the environment. It was found that a progressive narrowing of the concept of environment takes place during the course of the EIA process.  相似文献   
143.
144.
DNA damage in the form of cyclobutane pyrimidine dimers(CPDs) and (6-4) photopreducts(6-4PPs) induced by UV-B radiation in Arabidopsis thaliana at different temperatures was investigated using ELISA with specific monoclonal antibodies. CPDs and 6-4PPs increased during 3 h UV-B exposure, but further exposure led to decreases. Contrary to the commonly accepted view that DNA damage induced by UV-B radiation is temperature-independent because of its photochemical nature, we found UV-B-induction of CPDs and 6-4PPs in Arabidopsis to be slower at a low than at a high temperature. Photorepair of CPDs at 24℃ was much faster than that at 0℃ and 12℃,with 50% CPDs removal during 1 h exposure to white light. Photorepair of 6-4PPs at 12℃ was very slow as compared with that at 24℃,and almost no removal of 6-4PPs was detected after 4 h exposure to white light at 0℃. There was evidence to suggest that temperaturedependent DNA damage and photorepair could have important ecological implications.  相似文献   
145.
Lake water and fish livers and gills of sahar (Tor putitora), spiny eel (Mastacembelus armatus), African magur (Clarias gariepinus), and tilapia (Oreochromis niloticus) from Lake Phewa, Nepal, were assessed for the concentrations of trace metals/elements and persistent organic pollutants. The lake water was neutral with low ionic and metallic concentrations as compared to high-altitude lakes of Nepal. The four elements Cu, Zn, Se, and Cd had highest concentrations in livers, indicating uptake from diet, whereas four other metallic elements Cr, Mn, Ni, and Pb had highest concentrations in gills, indicating uptake from lake water. O. niloticus tended to have most of trace metals in the liver at higher concentrations than the other species but significant differences among the different species were found only for Mn, Ni, and Zn in the gills. A pilot study on the concentrations of persistent organic pollutants in muscle revealed that dichlorodiphenyltrichloroethane and related compounds were the dominant organochlorine pesticides, having highest concentrations in C. gariepinus and lowest in O. niloticus.  相似文献   
146.
Cultivated and settlement areas were studied in a small area (14 km2) in South Wollo, Ethiopia, by aerial photos, satellite images, field observations and interviews. Areas for cultivation/rural settlement decreased a few per cent between 1958 and 2013. Cultivated land per household slowly decreased in 1958–2003 but in 2003–2013 the annual decrease was 3–4 times higher. New farm buildings are often built on cultivated land, and abandoned buildings areas return to cultivation. Rainwater harvesting ponds have increased the areas with perennial crops that are important as a source of income. Tin roofed buildings are signs of improved livelihood. Very small farm size and rain-dependent agriculture combined with climate variability make food security vulnerable. Land-use inventories including remote sensing and local knowledge would be a valuable approach to assess livelihood needs. Further, it should involve decision makers at different levels, but local agricultural extension officers may play a central role.  相似文献   
147.
In a landscape of fragmented private ownership, the need to coordinate game management across large areas presents challenges for landowners and public agencies alike. This paper describes how a recent reorganization of moose management in Norway achieves landscape-level planning while maintaining a tradition of local management by hunting teams. These two seemingly contradictory imperatives – coordinating wildlife management across large areas while keeping benefits and control in the hands of local resource users – are resolved through a nesting of management institutions, wherein the state serves a regulatory function and mid-level government (the county) serves to facilitate inter-local cooperation. This paper documents how the system is structured and describes the balance of incentives that enable the system to work. Information was gathered via interviews with staff at the Norwegian Directorate for Nature Management (now called the Norwegian Environment Agency), with wildlife management officials at the municipal level, with hunters, and from the most recent regulatory documents.  相似文献   
148.
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   
149.
Helander B  Bignert A  Asplund L 《Ambio》2008,37(6):425-431
This paper summarizes results from the monitoring of reproduction of white-tailed sea eagle in Sweden 1965-2006. Since 1989 the eagle population on the Swedish Baltic coast has been included in the National Environment Monitoring Program as an indicator species for potentially harmful chemicals. The percentage of successfully reproducing pairs and nestling brood size decreased in synchrony with rising concentrations of contaminants in the 1950s on into the 1970s. Mean productivity was 1.3 young per pair prior to 1950 and decreased to 0.3 in 1965-1985. Dichlorodiphenyldichloroethene (DDE) in eagle eggs decreased from a range of annual means in 1965-1974 of 600-1200 microg g(-1) (lipid weight) to 60-140 microg g(-1) in 1996-2005. Total polychlorinated biphenyl (PCB) concentrations averaged above 1000 microg g(-1) into the early 1980s and remained in the range of 250-500 microg g(-1) in 1996-2005. Productivity began to improve when concentrations of DDE and PCBs dropped below approximately 300 and 800 microg g(-1), respectively. Brood size remains below the pre-1950 level in one coastal region, indicating a possible impact from other contaminants. The power to detect significant trends under the program is presented and discussed: if white-tailed sea eagle reproduction had been monitored earlier during the 20th century, the negative impact of dichlorodiphenyltrichloroethane (DDT, source of DDE) would have been signaled as early as the 1950s in the Baltic Sea. The dramatic fall of white-tailed sea eagle reproduction under the influence of DDT and PCBs, and the subsequent rise following their ban, illustrates the usefulness of raptors like sea eagles as sentinels for environmental pollutants.  相似文献   
150.
Hydroxylated polybrominated diphenyl ethers (OH-PBDEs) and methoxylated polybrominated diphenyl ethers (MeO-PBDEs) are present in the ecosystem of the Baltic Sea. OH-PBDEs are known to be both natural products from marine environments and metabolites of the anthropogenic polybrominated diphenyl ethers (PBDEs), whereas, MeO-PBDEs appear to be solely natural in origin. Polybrominated dibenzo-p-dioxins (PBDDs) are by-products formed in connection with the combustion of brominated flame retardants (BFRs), but are also indicated as natural products in a red alga (Ceramium tenuicorne) and blue mussels living in the Baltic Sea. The aims of the present investigation were to quantify the OH-PBDEs and MeO-PBDEs present in C. tenuicorne; to verify the identities of PBDDs detected previously in this species of red alga and to investigate whether cyanobacteria living in this same region of the Baltic Sea contain OH-PBDEs, MeO-PBDEs and/or PBDDs. The red alga was confirmed to contain tribromodibenzo-p-dioxins (triBDDs), by accurate mass determination and additional PBDD congeners were also detected in this sample. This is the first time that PBDDs have been identified in a red alga. The SigmaOH-PBDEs and SigmaMeO-PBDEs concentrations, present in C. tenuicorne were 150 and 4.6 ng g(-1) dry weight, respectively. In the cyanobacteria 6 OH-PBDEs, 6 MeO-PBDEs and 4 PBDDs were detected by mass spectrometry (electron capture negative ionization (ECNI)). The PBDDs and OH-PBDEs and MeO-PBDEs detected in the red alga and cyanobacteria are most likely of natural origin.  相似文献   
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