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61.
Bioassays as well as biochemical responses (biomarkers) in ecosystems due to environmental stress provide us with signals (environmentally signalling) of potential damage in the environment. If these responses are perceived in this early stage in ecosystems, the eventual damage can be prevented. Once ecosystem damage has occurred, the remedial action processes for recovery could be expensive and pose certain logistical problems. Ideally, “early warning signals” in ecosystems using sensing systems of biochemical responses (biomarkers) would not only tell us the initial levels of damage, but these signals will also provide us with answers by the development of control strategies and precautionary measures in respect to the European Water Framework Directive (WFD). Clear technical guidelines or technical specifications on monitoring are necessary to establish and characterise reference conditions for use in an ecological status classification system for surface water bodies. For the Ecotoxicological Risk Assessment (ERA) of endocrine effects we used an approach of the exposure – dose – response concept. Based on the “Ecototoxicological Classification System of Sediments” that uses pT-values to classify effects in different river systems, we transferred the bio-monitoring data to the five-level ecological system of the WFD. To understand the complexity of the structure of populations and processes behind the health of populations, communities and ecosystems an ERA should establish links between natural factors, chemicals, and biological responses so as to assess causality. So, our ecological monitoring assessment has incorporated exposure & effects data. 相似文献
62.
Lindahl P Maquet A Hult M Gasparro J Marissens G González de Orduña R 《Journal of environmental radioactivity》2011,102(2):163-169
The distribution of natural radionuclides was studied in winter wheat plants collected from three sites in Belgium during 2004-2007. Activity concentrations of 40K, 226Ra, 228Ra and 228Th in organically and conventionally grown wheat, and in the corresponding soil samples, were determined using ultra low-level gamma-ray spectrometry. The observed soil-to-wheat concentration ratios were calculated for the different parts of the wheat plant (root, stem and grain) in the two agricultural systems (organic and conventional). There were large variations in radionuclide activity concentrations between the sites and fields, but no significant difference between conventionally and organically grown wheat plants was observed. 相似文献
63.
The USGS Water Availability and Use Science Program: Needs,Establishment, and Goals of a Water Census 下载免费PDF全文
Ari M. Michelsen Sonya Jones Eric Evenson David Blodgett 《Journal of the American Water Resources Association》2016,52(4):836-844
Many reports have recognized the need for a national water census for the United States and have called upon the U.S. Geological Survey to undertake this challenge. For example, the National Science and Technology Council stated: “The United States has a strong need for an ongoing census of water that describes the status of our Nation's water resource at any point in time and identifies trends over time.” Responding to the need for this information, the U.S. Congress established the SECURE Water Act. The directives are to provide a more accurate assessment of the status of the water resources of the United States; determine the quantity of water available for beneficial uses; identify long‐term trends in water availability; assist in determination of the quality of the water resources; and develop the basis for an improved ability to forecast the availability of water for future economic, energy production, and environmental uses. This article provides summary and new information on the process and progress on work to estimate water budget components nationwide, involvement of stakeholder interests, efforts to examine water‐use characteristics throughout the Nation, studies of water availability in geographically focused areas and the initiation of methods to provide open access to existing and new water resources information contributing to Open Water Data Initiative (OWDI) efforts and objectives. 相似文献
64.
Weitkamp G Van den Berg AE Bregt AK Van Lammeren RJ 《Journal of environmental management》2012,95(1):17-28
In the last decade policy makers have increasingly recognized the need to include people's perceptions in methods for describing landscape quality. At the same time, a third wave of Geographic Information Systems (GIS) has become available that make it technically possible to model landscape quality in a realistic manner. However, as there is often a mismatch between science and policy, it remains unclear to what extent perception-based models developed by scientists can be useful to policy makers. The aim of the present study was to evaluate the usefulness to policy making of a GIS-based procedure for describing perceived landscape openness. To this end, a workshop was organized which was attended by eight Dutch policy makers who acted as representatives of their province (region). The Group Decision Room (GDR) technique was used to elicit the policy makers' evaluations of the procedure in an anonymous and reliable manner. The procedure was presented to the policy makers using cases from their own province, which they assessed using a mixture of qualitative and quantitative methods. The results show that policy makers rated the procedure as being highly relevant to policy making, scientifically credible, usable by policy makers and feasible to implement in the policy making process. They especially appreciated the flexibility and transparency of the procedure. The policy makers concluded that the procedure would be of most value for monitoring landscape changes and for analysing impacts on landscape openness in land use scenario studies. However, they requested guidelines for proper implementation of the various options in the procedure. In general, the current study shows that explicit and transparent evaluation of the usefulness of GIS-based tools can aid integration at the science-policy interface and help to ensure that both scientists and policy makers are informed of interrelated options and requirements. 相似文献
65.
Gerd Scholl Frieder Rubik Harri Kalimo Katja Biedenkopf Ólöf Söebech 《Natural resources forum》2010,34(1):39-50
Policy-makers are increasingly recognising that the promotion of more sustainable consumption patterns is an indispensable prerequisite for achieving sustainable development in the long term. Policy documents and action plans have been published, and a wide array of policy instruments has been implemented with the aim of reducing the environmental and social burdens of consuming goods and services. But what are the latest trends and innovative approaches in sustainable consumption (SC) policies? What could be learnt for future policy-making? Based on an overview of European policy instruments and several case studies, the paper discusses instructive examples of SC policy instruments, in particular the Danish information campaign "One Tonne Less", the Dutch tax incentive scheme "Green Funds", the British "Red/Green calculator", and the pan-European internet platform "TopTen". Important features of novel policies — such as adaptability and collective action — are identified, and recommendations for future policies are presented. The recommendations refer to the foundation of SC policies, to the specific approach taken, to the applied instruments, and to the proper documentation of the implemented policies. 相似文献
66.
Peter O. Otieno P. Okinda Owuor Joseph O. Lalah Gerd Pfister Karl-Werner Schramm 《Environmental monitoring and assessment》2013,185(3):2723-2733
This study reports evidence of increased chlorpyrifos contamination in sediment and water in Lake Naivasha following its intensive application in the horticultural farms in the catchment area. Analytical results show that levels of chlorpyrifos residues were influenced by climate-induced rainfall pattern with higher levels reported during period of heavy precipitation with significant decrease during low rainfall. On average, the levels ranged between 14.8 and 32.8 ng g?1 in sediment during rainy season compared to a range of 8.5–16.6 ng g?1 in the dry season. Additionally, the mean concentration of chlorpyrifos in water ranged between 8.61 and 22.4 μg L?1 during rainy season and below detection limit (bdl) ?13.6 μg L?1 in dry season as quantified by enzyme-linked immunosorbent assay. Meanwhile, independent t test analysis indicated that there was significant difference in concentration at p?≤?0.05 between the seasons with respect to sediment and water samples. This demonstrated that climate-induced variations had considerable influence on contamination. While diazinon and carbofuran were equally applied intensively, their levels were below the detection limit in the all the samples analyzed. ELISA results were validated by the capillary-HPLC photodiode-array detector instrument analysis, and statistical comparison showed no significant difference between them. It was evident that chlorpyrifos residues determination in water and sediment by ELISA can be a useful strategy in environmental management and monitoring program, and a complimentary analytical tool to high performance liquid chromatography. Levels of chlorpyrifos detected in sediment and water were found to exceed recommended criteria for protection of aquatic life and preservation of water quality and may be hazardous if not regularly monitored. 相似文献
67.
Diver-towed global positioning systems (GPS) handhelds have been used for a few years in underwater monitoring studies. We
modeled the accuracy of this method using the software KABKURR originally developed by the University of Rostock for fishing
and marine engineering. Additionally, three field experiments were conducted to estimate the precision of the method and apply
it in the field: (1) an experiment of underwater transects from 5 to 35 m in the Southern Chile fjord region, (2) a transect
from 5 to 30 m under extreme climatic conditions in the Antarctic, and (3) an underwater tracking experiment at Lake Ranco,
Southern Chile. The coiled cable length in relation to water depth is the main error source besides the signal quality of
the GPS under calm weather conditions. The forces used in the model resulted in a displacement of 2.3 m in a depth of 5 m,
3.2 m at a 10-m depth, 4.6 m in a 20-m depth, 5.5 m at a 30-m depth, and 6.8 m in a 40-m depth, when only an additional 0.5 m
cable extension was used compared to the water depth. The GPS buoy requires good buoyancy in order to keep its position at
the water surface when the diver is trying to minimize any additional cable extension error. The diver has to apply a tensile
force for shortening the cable length at the lower cable end. Repeated diving along transect lines from 5 to 35 m resulted
only in small deviations independent of water depth indicating the precision of the method for monitoring studies. Routing
of given reference points with a Garmin 76CSx handheld placed in an underwater housing resulted in mean deviances less than
6 m at a water depth of 10 m. Thus, we can confirm that diver-towed GPS handhelds give promising results when used for underwater
research in shallow water and open a wide field of applicability, but no submeter accuracy is possible due to the different
error sources. 相似文献
68.
Gerd W. Buschhorn 《Die Naturwissenschaften》1998,85(12):565-574
HERA, a high energy particle collider at the Deutsches Elektronensychrotron DESY in Hamburg, allows investigation of the
structure of the proton with a spatial resolution of 10 cm, corresponding to about 1/1000 of its diameter. This view deep into the inner properties of matter is obtained from the
scattering of high-energy electrons or positrons from high-energy protons. With its 6.3 km circumference, HERA can be regarded
as a gigantic electron microscope. The high energies available at HERA allow a wealth of further studies on the properties
of elementary particles and their interactions. After a brief review of earlier experiments, the article describes the concept
of HERA and the detectors H1 and ZEUS, with which the scattering events are analyzed, as well as some of the physics results. 相似文献
69.
Smith–Lemli–Opitz (RSH) syndrome (SLOS, OMIM 270400) is a relatively common, autosomal recessive disorder of cholesterol biosynthesis with a broad spectrum of phenotypic abnormalities caused by mutations of the 7-dehydrocholesterol reductase gene (DHCR7) on chromosome 11. Prenatal diagnosis can be established by detection of elevated 7-dehydrocholesterol or of SLOS-causing mutations in the DHCR7 gene. We report here our experience with molecular prenatal diagnosis of SLOS. Mutation analysis of the DHCR7 gene was performed in chorionic villus samples of 13 pregnancies of couples with a family history of SLOS and known SLOS genotypes. This approach is accurate and reliable. If facilities for biochemical analysis are not available, or in cases with ambiguous biochemical patterns, molecular prenatal diagnosis is an attractive, alternative option. Copyright © 2002 John Wiley & Sons, Ltd. 相似文献
70.