全文获取类型
收费全文 | 2852篇 |
免费 | 2篇 |
国内免费 | 34篇 |
专业分类
安全科学 | 56篇 |
废物处理 | 139篇 |
环保管理 | 290篇 |
综合类 | 390篇 |
基础理论 | 1095篇 |
环境理论 | 1篇 |
污染及防治 | 558篇 |
评价与监测 | 186篇 |
社会与环境 | 173篇 |
出版年
2022年 | 2篇 |
2021年 | 7篇 |
2020年 | 1篇 |
2019年 | 2篇 |
2018年 | 110篇 |
2017年 | 116篇 |
2016年 | 181篇 |
2015年 | 50篇 |
2014年 | 12篇 |
2013年 | 19篇 |
2012年 | 423篇 |
2011年 | 209篇 |
2010年 | 25篇 |
2009年 | 30篇 |
2008年 | 47篇 |
2007年 | 66篇 |
2006年 | 66篇 |
2005年 | 393篇 |
2004年 | 528篇 |
2003年 | 406篇 |
2002年 | 43篇 |
2001年 | 39篇 |
2000年 | 18篇 |
1999年 | 30篇 |
1998年 | 4篇 |
1997年 | 9篇 |
1996年 | 3篇 |
1995年 | 10篇 |
1994年 | 4篇 |
1993年 | 2篇 |
1992年 | 3篇 |
1991年 | 7篇 |
1990年 | 4篇 |
1989年 | 4篇 |
1975年 | 2篇 |
1974年 | 2篇 |
1973年 | 1篇 |
1972年 | 2篇 |
1971年 | 1篇 |
1969年 | 1篇 |
1968年 | 1篇 |
1967年 | 1篇 |
1966年 | 2篇 |
1961年 | 1篇 |
1957年 | 1篇 |
排序方式: 共有2888条查询结果,搜索用时 15 毫秒
991.
The paper presents new studies about the removal efficiencies and characterization of the Municipal Wastewater Treatment Plant (MWWTP) in Kayseri, Turkey, which is serving for 800,000 population equivalents with the capacity of 110,000 m(3)/day, between 2006 and 2009. Kayseri discharges its effluents to Karasu Creek that downstream joins the Kizilirmak river, the longest river in Turkey discharging into the Black Sea. Four years of operation data between 2006 and 2009 calendar years were obtained from KASKI General Directorate. Influent and effluent samples were collected daily and suspended solids (SS), chemical oxygen demand (COD), biochemical oxygen demand in 5 days (BOD(5)), total nitrogen (TN), and total phosphorus (TP) were measured, aiming to study the evolution of the removal efficiencies for each year. The following yearly mean removal efficiencies were performed in the treatment plant: 94%, 97%, 97%, 95% for SS; 94%, 96%, 95%, 95% for COD; 98%, 98%, 98%, 98% for BOD(5); 84%, 87%, 89%, 82% for TN; and 71%, 86%, 80%, 86% for TP, in 2006, 2007, 2008, and 2009, respectively. The performance of Kayseri MWWTP was given both in terms of influent and effluent quality and in comparison with the current legislation on discharge limits to the receiving body. During the studied period, mean concentrations in the effluent did not exceed the imposed limits, but sometimes, higher values were noticed for SS, TN, and TP. In conclusion, the plant performances concerning these parameters were excellent and Kayseri MWWTP was operating efficiently according to the conventional control parameters. 相似文献
992.
Suspended sediment concentration (SSC) is generally determined from the direct measurement of sediment concentration of river or from sediment transport equations. Direct measurement is very costly and cannot be conducted for all river gauge stations. Therefore, correct estimation of suspended sediment amount carried by a river is very important in terms of water pollution, channel navigability, reservoir filling, fish habitat, river aesthetics and scientific interests. This study investigates the feasibility of using turbidity as a surrogate for SSC as in situ turbidity meters are being increasingly used to generate continuous records of SSC in rivers. For this reason, regression analysis (RA) and artificial neural networks (ANNs) were employed to estimate SSC based on in situ turbidity measurements. The SSC was firstly experimentally determined for the surface water samples collected from the six monitoring stations along the main branch of the stream Harsit, Eastern Black Sea Basin, Turkey. There were 144 data for each variable obtained on a fortnightly basis during March 2009 and February 2010. In the ANN method, the used data for training, testing and validation sets are 108, 24 and 12 of total 144 data, respectively. As the results of analyses, the smallest mean absolute error (MAE) and root mean square error (RMSE) values for validation set were obtained from the ANN method with 11.40 and 17.87, respectively. However these were 19.12 and 25.09 for RA. It was concluded that turbidity could be a surrogate for SSC in the streams, and the ANNs method used for the estimation of SSC provided acceptable results. 相似文献
993.
Zhongshuo?Xu Jinjun?Li Yuying?Pan Xiaoli?ChaiEmail author 《Environmental monitoring and assessment》2016,188(4):229
The aim of this study was risk characterization of a replaced urban industrial land located north of Qingdao, in relation to heavy metals values. Soil concentrations of Cd, Pb, Cu, Ni, Cr, and Zn were analyzed. It was observed that the components of Cd, Pb, Cu, Ni, Cr, and Zn are about 2.22, 8.07, 4.70, 6.81, 2.65, and 3.0-folds, respectively, when compared with the local natural background values in Qingdao. The spatial distribution of heavy metals indicated that these hotspots for Cr and Zn located in the southwestern part, Ni and Cd in the middle of the south area, Pb in the northwest, and Cu in the middle of the east area. The values of pollution index and Nemerow integrated pollution index revealed that 100 % of soil samples were moderately or heavily contaminated by six heavy metals. From these results, human health risk assessment for sensitive population was performed according to two different land uses. For non-carcinogenic risk, the direct oral ingestion appeared to be the main exposure pathway followed by dermal and inhalation absorption. The HI values of Pb and Cr characterized for children were larger than 1, while HI values of each metal for adults in two scenarios were lower than 1. Besides, carcinogenic risk from inhalation exposure to Cr for children and adults in two scenarios all exceeded the safety limit. 相似文献
994.
Lorenzo?VilizziEmail author Ali?Serhan?Tarkan 《Environmental monitoring and assessment》2016,188(4):243
Although fish is widely consumed by humans for its nutritional properties, accumulation of heavy metals can pose serious health hazards. Widespread common carp Cyprinus carpio is cultured worldwide and represents an economically important species for fisheries in several countries. These include Turkey, where C. carpio often makes for a large part of the sales of the locally marketed fish and also for a traditional dish. This study provides a review of bioaccumulation of metals in tissues of C. carpio from water bodies of Anatolia and also includes reference to worldwide studies. From 42 water bodies across the region, 27 metals in total were studied, of which Cd, Cr, Cu, Fe, Mn, Ni, Pb and Zn were the most widely analysed, mainly in the muscle, liver and gill tissues. Amongst the potentially toxic metals, Cd, Cr and Pb occurred in several water bodies at concentrations not only above maximum allowed limits but also higher relative to other water bodies worldwide, even though As, Hg and Ni were also sometimes present at potentially hazardous concentrations. The essential metals Cu, Fe, Mn, Se and Zn were detected at various concentrations, with the latter two occasionally above limit. All water bodies flagged as having especially critical (i.e. above limit) concentrations of toxic metals supported C. carpio fisheries from highly populated regions, raising concern about food safety and calling for preventative measures. Given the significantly lower bioaccumulation levels in the muscle relative to the liver and gill tissues, it is suggested that consumption of C. carpio as fillets may be safer than after processing into e.g. meat balls and sausages. The limits of 1.0 μg/g for Cr and 1.15 μg/g for Se, currently lacking from the Turkish food safety legislation, are proposed, and it is suggested that a similar meta-analytical approach as adopted in this study may benefit other countries where C. carpio represents an important fisheries resource. 相似文献
995.
Alves RR Vieira KS Santana GG Vieira WL Almeida WO Souto WM Montenegro PF Pezzuti JC 《Environmental monitoring and assessment》2012,184(11):6877-6901
For many millennia humans and reptiles have interacted, but the attitude of humans towards these animals has depended on culture, environment, and personal experience. At least 719 reptile species are known to occur in Brazil and about 11% of this fauna has been exploited for many different purposes, including bushmeat, leather, ornamental and magic/religious uses, and as folk medicines. Brazil can therefore serve as an interesting case study for better understanding reptile use by human societies, and the present paper catalogues some of the reptile species being used in Brazil and discusses implications for their conservation. A literature review indicated that 81 reptile species are culturally important in this country, with 47 (58%) species having multiple uses, 54 being used for medicinal purposes, 38 as food, 28 for ornamental or decorative purposes, 20 used in magic/religious practices, 18 as pets, and 40 are commonly killed when they come into contact with humans. Regarding their conservation status, 30 (37.5%) are included on State's Red List, Brazilian Red List or the IUCN Red List. There are many forms of interaction between reptiles and humans in Brazil-although most of them are quite negative in terms of wildlife conservation-which reinforces the importance of understanding such uses and interactions in the context of protecting reptiles in Brazil. A better understanding of the cultural, social, and traditional roles of these reptiles is fundamental to establishing management plans for their sustainable use. 相似文献
996.
Cornelia Hesse Valentina Krysanova Anja Vo? 《Environmental Modeling and Assessment》2012,17(6):589-611
For a long time, watershed models focused on the transport of chemicals from the terrestrial part of the watershed to the surface water bodies by leaching and erosion. After the substances had reached the surface water, they were routed through the channel network often without any further transformation. Today, there is a need to extend watershed models with in-stream processes to bring them closer to natural conditions and to enhance their usability as support tools for water management and water quality policies. This paper presents experience with implementing in-stream processes in a ecohydrological dynamic watershed model and its application on the large scale in the Saale River basin in Germany. Results demonstrate that new implemented water quality parameters like chlorophyll a concentrations or oxygen amount in the reach can be reproduced quite well, although the model results, compared with results achieved without taking into account algal and transformation processes in the river, show obvious improvement only for some of the examined nutrients. Finally, some climate and water management scenarios expected to impact in-stream processes in the Saale basin were run. Their results illustrate the relative importance of physical boundary conditions on the amount and concentration of the phytoplankton, which leads to the conclusion that measures to improve water quality should not only take nutrient inputs into account but also climate influences and river morphology. 相似文献
997.
Sophie?GourguetEmail author Olivier?Thébaud Sarah?Jennings L.?Richard?Little Catherine?M.?Dichmont Sean?Pascoe Roy?A.?Deng Luc?Doyen 《Environmental Modeling and Assessment》2016,21(3):371-389
Fisheries management must address multiple, often conflicting objectives in a highly uncertain context. In particular, while the bio-economic performance of trawl fisheries is subject to high levels of biological and economic uncertainty, the impact of trawling on broader biodiversity is also a major concern for their management. The purpose of this study is to propose an analytical framework to formally assess the trade-offs associated with balancing biological, economic and non-target species conservation objectives. We use the Australian Northern Prawn Fishery (NPF), which is one of the most valuable federally managed commercial fisheries in Australia, as a case study. We develop a stochastic co-viability assessment of the fishery under multiple management objectives. Results show that, due to the variability in the interactions between the fishery and the ecosystem, current management strategies are characterized by biological and economic risks. Results highlight the trade-offs between respecting biological, economic and non-target species conservation constraints at each point in time with a high probability and maximizing the net present value of the fishery. 相似文献
998.
Using the analytical hierarchy process to assess the environmental vulnerabilities of basins in Taiwan 总被引:3,自引:0,他引:3
Every year, Taiwan endures typhoons and earthquakes; these natural hazards often induce landslides and debris flows. Therefore,
watershed management strategies must consider the environmental vulnerabilities of local basins. Because many factors affect
basin ecosystems, this study applied multiple criteria analysis and the analytical hierarchy process (AHP) to evaluate seven
criteria in three phases (geographic phase, hydrologic phase, and societal phase). This study focused on five major basins
in Taiwan: the Tan-Shui River Basin, the Ta-Chia River Basin, the Cho-Shui River Basin, the Tseng-Wen River Basin, and the
Kao-Ping River Basin. The objectives were a comprehensive examination of the environmental characteristics of these basins
and a comprehensive assessment of their environmental vulnerabilities. The results of a survey and AHP analysis showed that
landslide area is the most important factor for basin environmental vulnerability. Of all these basins, the Cho-Shui River
Basin in central Taiwan has the greatest environmental vulnerability. 相似文献
999.
1000.
Zusammenfassung
Hintergrund und Ziel Die Exposition gentechnisch ver?nderter Kulturpflanzen erfordert die Beobachtung ihrer Umweltwirkungen. Ziel der Beitragsserie
über die Beobachtung ?kologischer Wirkungen von GVO ist es, den hierzu erreichten Stand der Wissenschaft vorzustellen. Da
bei einem Bundesl?nder und ggf. europ?ische Staaten übergreifenden Monitoring besonders auf methodisch vergleichbare und r?umlich
aussagekr?ftige Daten zu achten ist, werden in diesem einführenden Beitrag wissenschaftstheoretische und statistische Grundlagen
des Monitoring sowie die Standardisierung der Beobachtungsverfahren behandelt.
Schwerpunkte Im Mittelpunkt stehen zun?chst ?kologische Anforderungen an das GVO-Monitoring. Um mit GVO ggf. zusammenh?ngende Umweltver?nderungen
ermitteln zu k?nnen, ist eine Eingliederung in bestehende Umweltbeobachtungsprogramme erforderlich. GVO-Exposition und-Wirkung
sind aufeinander bezogen über die Organisationsstufen ?kologischer Systeme hinweg zu erfassen. Ein effizientes und suffizientes
Monitoring bedarf eines wissenschaftstheoretisch und statistisch soliden Designs. Deshalb werden einem weiteren Schwerpunkt
dieses Beitrags wissenschaftstheoretische Grundlagen der Hypothesenbildung und-prüfung behandelt. Hierfür bedarf es Daten,
die mehreren, im Einzelnen behandelten Qualit?tskriterien entsprechen müssen. Eines dieser Kriterien ist die r?umliche und
zeitliche Verallgemeinerungsf?higkeit der Monitoring-Befunde, die in dem dritten Schwerpunkt des Beitrags dargestellt wird.
Schlussfolgerungen Für die Prüfung von Hypothesen über Umweltfolgen von GVO sind konsequent ?kosystemforschung und Monitoring eng miteinander
zu vernetzen. Denn sie erfüllen komplement?re Funktionen, die für das Monitoring der Umweltwirkungen von GVO von gro?er praktischer
und wissenschaftlicher Bedeutung sind.
Empfehlungen Das GVO-Monitoring sollte in bestehende Programme der ?kosystemforschung und der Umweltbeobachtung eingebettet werden und
die ?kologischen Organisationsstufen sowie GVO-Exposition und-Wirkung einschlie?en. Die Lokalisierung der Messorte sollte
die erwartete Exposition oder Wirkung berücksichtigen.
Perspektiven Weitere Beitr?ge dieser Serie werden die Messplanung, das Pollenmonitoring und die r?umliche Verallgemeinerung von Ergebnissen
standortspezifischer Messungen oder Modellierungen behandeln.
Environmental monitoring of ecological impacts of GMOs
Goal, Scope and Background The release of genetically modified organisms (GMOs) may result in ecological impacts to be monitored. This series presents the state-of-art concerning the environmental monitoring of ecological impacts of GMOs. Since this monitoring is conducted by several authorities, the methodical comparability and spatial validity of the monitoring data is crucial. Thus, the respective fundamentals of philosophy of science and of statistics as well as the methodical standardisation form the focus of this article. Main Features At first, the monitoring requirements will be described from the viewpoint of ecology. Consequently, the GMO monitoring needs to be integrated into existing programmes. Exposure and effects of GMOs have to be monitored across the hierarchy of ecological organisation. For monitoring to be efficient and sufficient, the design must be founded in terms of philosophy of science and statistics. Hence the fundamentals concerning the verification of hypotheses represent another feature of this article. The data used for the verification of hypotheses must comply with quality criteria. One of these criteria is the spatial and temporal extrapolation of the monitoring results, which is the third feature in this introductory article. Conclusions The evaluation of hypotheses on GMO impacts requires the linkage to ecosystems research and environmental monitoring. These both are, in terms of methodology, complementary and of significant technical and scientific value for GMO monitoring. Recommendations GMO-monitoring should closely be connected with ecosystems research and environmental monitoring. The levels of ecological organisation should be covered as well as the exposure and the effects of GMOs. The expected GMO exposure and effects should be considered by localising the monitoring sites. Perspectives Further articles of this series will deal with network designing, GMO pollen monitoring and extrapolation of site-specific measurements and modelling results.相似文献