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951.
Modeling Abundance Index Data from Anuran Calling Surveys 总被引:2,自引:0,他引:2
J. ANDREW ROYLE 《Conservation biology》2004,18(5):1378-1385
Abstract: Evaluation of anuran populations is commonly based on calling surveys that report categorical abundance index data. I present a statistical model for abundance index data that are observations representing ordered abundance classes (e.g., none, some, many). The proposed model provides a formal treatment of detection probability, factors that affect detection, and variation in abundance. The model can be viewed as a generalization of that proposed by MacKenzie et al. (2002) for estimating site-occupancy rates in that it allows for more than two abundance classes. Because the abundance distribution is characterized by multiple abundance classes, it may be more sensitive to subtle changes in the underlying abundance that may go undetected with simple occupancy estimates under which sites are characterized merely as occupied or not. The method is most immediately applicable to surveys of anurans in which index data related to the intensity of calling activity are collected. I applied the proposed method to calling index data from the green frog ( Rana clamitans ) collected as part of the North American Amphibian Monitoring Program. The best model indicated considerable variation in detectability over time and in response to temperature. The resulting adjusted (for detectability) abundance-state distribution demonstrates the negative bias in abundance state obtained from simplistic summaries of calling index data that disregard these sources of variation in detectability. 相似文献
952.
H. J. O’Neill R. A. Bingham Geoffrey D. Howell F. Colin Duerden Christopher Roberts 《Environmental management》1993,17(2):257-265
The ability to access information for use in decision making is a well-recognized need within the context of management sciences.
A similar need exists in order to make effective technical decisions pertaining to environmental resource management. Data
bases are the principle vehicle by which scientists, engineers, and resource managers store and access environmental information.
An integrated data-base mechanism is essential in order for federal agencies to manage programs such as enforcement of the
Canadian Environmental Protection Act (CEPA), state of the environment (SOE) reporting, and the environmental assessment and
review process (EARP). A data-base structure and data dissemination mechanism under current development within Environment
Canada, Conservation and Protection, Atlantic Region, is presented along with some of its operational benefits and constraints. 相似文献
953.
Malcolm Newson 《Journal of Environmental Planning and Management》1991,34(2):72-74
This paper is concerned with the way in which academics who are drawn into the Environmental Assessment process use their skill, knowledge and understanding. It identifies shortcomings and pitfalls and stresses the importance of integrity and monitoring. 相似文献
954.
Administrative machinery has been set up to regulate and control most of the emissions that are known to have severe local
consequences, such as the discharge of raw sewage into rivers and lakes and the smokestack emission of air pollutants. Now,
the nature of environmental degradation is usually different. We are faced with pollutants and effects with more subtle cause-effect
relationships, often characterized by larger geographic areas of interest and longer term potential damage; the potential
risk is now more chronic than acute. Acid rain and climate change are good examples, in that they are associated with a variety
of pollutants from a number of sources and damage to ecosystems occurs over many years. It is argued that monitoring programs
should evolve to reflect the changing nature of the environmental problems they are addressing. It is now necessary to consider
interactions among many pollutants, mixing among the various media, and potentially affecting many components of the ecosystem
in both indirect and direct ways. Here, integrated monitoring and analysis is presented as a unifying strategy to bring together
different measurement methodologies in different disciplines, addressing environmental questions of complexity beyond the
scope of many existing activites that have a classical narrower focus. The underlying concept is of nested networks, each
tier being composed of sites selected for specific purposes but arranged to maximize the number of common sites where more
multidisciplinary questions can be addressed. 相似文献
955.
As human influences fragment native communities and ecosystems, remaining land must be better managed to conserve many elements
of biodiversity. Much of this land is privately held, yet traditional private land-use management practices often further
diminish biodiversity by promoting favored or edge-adapted species.
Today, private land stewards are increasingly aware of and concerned about biodiversity, but little guidance exists for them
to make land-use decisions incorporating principles and knowledge from conservation biology. Consequently, most management
strategies are highly subjective. This article addresses that problem by introducing current conservation wisdom to management
and use of private lands. The result is a model program for developing land management plans, with the goal of maintaining
viable populations and natural distributions of native species and communities from a landscape perspective.
The program establishes a protocol for classifying sites according to the importance of their species, communities, and other
elements to global and regional biodiversity. These site classifications are based on the management objectives necessary
to maintain important elements. Once managers classify a site, the program provides management standards, general stewardship
principles, examples of land management strategies, and basic monitoring and evaluation procedures. 相似文献
956.
The quality of scientific information in policy-relevant fields of research is difficult to assess, and quality control in
these important areas is correspondingly difficult to maintain. Frequently there are insufficient high-quality measurements
for the presentation of the statistical uncertainty in the numerical estimates that are crucial to policy decisions. We propose
and develop a grading system for numerical estimates that can deal with the full range of data quality—from statistically
valid estimates to informed guesses. By analyzing the underlying quality of numerical estimates, summarized as spread and
grade, we are able to provide simple rules whereby input data can be coded for quality, and these codings carried through
arithmetical calculations for assessing the quality of model results. For this we use the NUSAP (numeral, unit, spread, assessment,
pedigree) notational system. It allows the more quantitative and the more qualitative aspects of data uncertainty to be managed
separately. By way of example, we apply the system to an ecosystem valuation study that used several different models and
data of widely varying quality to arrive at a single estimate of the economic value of wetlands. The NUSAP approach illustrates
the major sources of uncertainty in this study and can guide new research aimed at the improvement of the quality of outputs
and the efficiency of the procedures. 相似文献
957.
Russell R. Schoof Edward H. Seely Arlin D. Nicks Carlton D. Edens Paul B. Allen 《Journal of the American Water Resources Association》1968,4(4):54-63
Daily, monthly, and yearly summaries of streamflow and sediment transport are computed from continuous gage height records and discrete measurements of sediment concentration and discharge rate. The system includes computer computation of discharge measurement notes and an accuracy check of gage height and time input data. Maximum volumes of runoff for selected time intervals up to eight days and flow duration data can also be compiled. Electronic data processing equipment including a chart reader, card punch, computers, and card sorter are used. The system software includes 12 Fortran programs. 相似文献
958.
Using specially designed temperature profiling equipment, two surveys were conducted during thermal backwashing operations at Pilgrim Nuclear Power Station to determine the spatial and temporal extent of temperature rises above ambient. Thermal backwashing is a process where biofouling is combated by a heat treatment procedure. Backwashing formed a thermal plume about 5- to 6-ft thick (1.5- to 1.8-m) in front of the intake screenwall. Maximum observed surface temperatures were 101.0°F (38.3°C), representing a rise (T) of about 43.4°F (24.1°C) above ambient. The frontal zone of the plume spread gradually seaward at about 0.2 kn. Its outer edge became thinner and rapidly cooled, presumably by advection and turbulent diffusion associated with currents from the reverse pumping and local changes from dissipation to the atmosphere. Along the intake shoreline, the plume was often less than 1 ft (0.3 m) thick. Most of the hot water was dissipated within several hundred feet of the intake with Ts of about 10.0 to 15.0°F (5.6 to 8.3°C) above ambient. Under the influence of 15 mph southwesterly winds during the second survey, some warmed water was apparently carried beyond the outer breakwaters into Cape Cod Bay. These surveys provided real-time data indicating that the backwashing operation caused a relatively thin thermal plume, which spread rapidly from the intake out across the study area and along the seaward breakwater. Within a few hours these backwash thermal plumes were completely dissipated.Formerly affiliated with Normandeau Associates, Inc., Bedford, New Hampshire. 相似文献
959.
Water quality criteria were developed for delivery waters to Everglades National Park. The park receives a minimum of 12.34 m3/sec (315,000 acre-ft/yr) of water from controlled sources external to its boundary. These waters often originate from areas that are or potentially are impacted from urban and agricultural developments. When, in 1970, the U.S. Congress guaranteed minimum water deliveries to Everglades National Park, it also required that these waters be of good quality.The Everglades National Park water quality data base was analyzed from 1970 to 1978 at both in-park and water delivery sites to determine the current level of delivery water quality and to select representative delivery sites. It was found that current delivery water quality was sufficiently high to be adopted as criteria against which future water quality could be compared. From the delivery sites S-12C and L-67A all data were combined from 1970–1978 for 36 parameters including macronutrients, heavy metals, and field parameters such as DO, pH, and specific conductance. Mean concentrations and upper limits were computed and tabulated for comparison during future monitoring programs. These criteria were subsequently adopted through a joint memorandum of agreement between the U.S. Army Corps of Engineers, South Florida Water Management District and the U.S. National Park Service. 相似文献
960.
Johan G. Borchert 《Journal of Environmental Planning and Management》1983,26(2):68-74
This paper is based on a shopping study carried out by the Department of Geography, University of Utrecht, during 1983. It is concerned with retail planning research for larger regions and starts with a state of the art review of retail planning research in the Netherlands. The aim, in developing a new research strategy, was to reduce time and costs through using computer facilit es for both data handling and data collection. There is discussion of methodology and some outcomes to demonstrate the possibilities of the strategy. 相似文献