全文获取类型
收费全文 | 121篇 |
免费 | 1篇 |
国内免费 | 1篇 |
专业分类
安全科学 | 5篇 |
废物处理 | 1篇 |
环保管理 | 16篇 |
综合类 | 18篇 |
基础理论 | 37篇 |
污染及防治 | 29篇 |
评价与监测 | 11篇 |
社会与环境 | 4篇 |
灾害及防治 | 2篇 |
出版年
2021年 | 4篇 |
2020年 | 1篇 |
2019年 | 1篇 |
2017年 | 1篇 |
2016年 | 6篇 |
2015年 | 5篇 |
2014年 | 4篇 |
2013年 | 17篇 |
2012年 | 4篇 |
2011年 | 7篇 |
2010年 | 1篇 |
2009年 | 2篇 |
2008年 | 3篇 |
2007年 | 6篇 |
2006年 | 6篇 |
2005年 | 3篇 |
2004年 | 2篇 |
2003年 | 1篇 |
2002年 | 3篇 |
2001年 | 1篇 |
2000年 | 1篇 |
1999年 | 1篇 |
1998年 | 1篇 |
1997年 | 2篇 |
1996年 | 2篇 |
1994年 | 3篇 |
1993年 | 3篇 |
1992年 | 3篇 |
1991年 | 1篇 |
1990年 | 2篇 |
1989年 | 1篇 |
1988年 | 1篇 |
1987年 | 4篇 |
1985年 | 5篇 |
1984年 | 2篇 |
1983年 | 3篇 |
1982年 | 2篇 |
1981年 | 1篇 |
1980年 | 3篇 |
1974年 | 1篇 |
1972年 | 1篇 |
1965年 | 1篇 |
1963年 | 1篇 |
排序方式: 共有123条查询结果,搜索用时 437 毫秒
91.
Richard A. Carpenter 《Environmental management》1980,4(1):13-20
Since October 1977, the East-West Environment and Policy Institute in Honolulu has been conducting a multinational collaborative project to enhance the preparation and utilization of natural systems assessments in developing countries. This paper presents some of the findings to date: 1. Channels are developing rapidly for transferring ecological knowledge into political and administrative decision making. 2. The systematic approach of ecology is replacing environmental quality as the organizing concept for information about natural resources and the environment. 3. Benefit-cost analysis is a promising method for integrating ecological knowledge into economic development decision making. 4. The lack of baseline information, inventories, and predictive capability will not be remedied soon or easily; thus priorities for ecological research are essential.This paper is adapted from a presentation at the Fifth Symposium on Tropical Ecology of the International Society for Tropical Ecology, University of Malaya, Kuala Lumpur, Malaysia, on 19 April 1979. Environmental Management, Vol. 4, No. 1, pp. 13–20 相似文献
92.
James S. Latimer Constance G. Carey Eva J. Hoffman James G. Quinn 《Journal of the American Water Resources Association》1988,24(4):791-800
ABSTRACT: The Pawtuxet River flows from a relatively rural area through some of the more highly industrialized sections of Rhode Island. During its journey, the river receives many municipal, industrial, and ground water sources of metal constituents. The present report is the first in a two part series in which the water quality of this urban river was evaluated by a chemical monitoring study of the sources, transport mechanisms, and fate of cadmium, chromium, copper, lead, and nickel in the river. The second paper will use the chemical data to derive and calibrate a steady-state water quality model for this river. The metal concentrations In the river tended to increase from the headwaters to the mouth with river stations nearest to point source outfalls showing elevated values. In some sections of the river, levels of a few of the metals could not be explained by the point sources; and other inputs, including sediment resuspension, axe proposed to make up this apparent unbalance. The ability of a municipal secondary treatment plant to remove metals was demonstrated, and the tie-in of the effluent from a major chemical company to the plant did not cause any observable deterioration in treatment efficiency. 相似文献
93.
p34cdc2 and cyclin B are two key proteins in the eukaryotic cell cycle control machinery. They thus could be important cell cycle markers for studies of environmental effects on cell cycle progression and on growth rate of marine phytoplankton. From July 1993 to March 1995, we used commercially available antibodies to examine the presence of their homologs in a marine phytoplankton species, Dunaliella tertiolecta Butcher. A p34cdc2-like protein was detected on the Western blots, with an apparent molecular mass as expected (34 kDa). Anti-cyclin B detected a protein of 63 kDa, a size similar to that of cyclin B in other organisms. The two proteins decreased from the exponential to the stationary growth phase. As determined on the Western blots, their abundance only changed slightly during the cell cycle, being slightly more abundant prior to cell division. Immunofluorescence performed for a partially synchronized culture showed that the fraction of the cell population that was positively stained by anti-p34cdc2 was highest at the time when the culture was mainly in the late G1 or early S phase, and in the late G2 or early M phase, respectively. The fraction was low when the culture was mainly in the S phase. Although further characterization is required to verify their identities, these two growth phase-related proteins appear to be p34cdc2 and cyclin B homologs, which may be useful in studying the cell cycle and growth rates of phytoplankton. 相似文献
94.
Marie-Louise Smith Constance Carpenter 《Environmental monitoring and assessment》1996,39(1-3):187-198
Ecological regionalization according to the USDA Forest Service National Hierarchical Framework of Ecological Units was undertaken for the New England-New York region. A topdown, map-overlay approach was used to map sections and subsections. Where available, landscape level units (LTAs) were aggregated and evaluated to supplement the subsection mapping. A regional collaborative effort was undertaken to counterbalance the shortfalls of a purely mechanistic approach. As a result of this process, 17 section and 58 draft subsection units were delineated for the New England-New York region. The sub-regional units developed reflect the strong correspondence among climate, topography and geography at this scale. Geologic factors, due to their influence on landform and mineral availability, are also reflected in the ecological unit boundaries. Efforts to apply the multifactor model at the sub-regional level have been hampered by the lack of scale appropriate information on a number of factors particularly meso-scale climate and potential natural community composition and distribution. Further research and investigation are required before these criterion are adequately met. 相似文献
95.
Invasive species can have severe effects on aquatic ecosystems. After invasions occur, eradication should be considered whenever the potential loss of ecosystem services outweighs the cost of the eradication method. Here we evaluate the possibility of destratifying Crystal Lake, Wisconsin, USA, to eradicate the invasive fish rainbow smelt (Osmerus mordax). We modeled the effects of three destratification scenarios (non-, low-, and high-mixing) using both physical and biological models. Field observations were used to calibrate the models. Water temperatures estimated from 18 unique DYRESM simulations were used in a bioenergetics model to estimate growth of five age classes of rainbow smelt under normal and destratified conditions. Our simulations indicate that destratification can eliminate optimal rainbow smelt thermal habitat resulting in mortality. Destratified lake temperatures also surpassed several physiological critical temperatures. Bioenergetics simulations predicted a weight loss of 45-55% in yearling and adult rainbow smelt. We found that destratification is potentially effective for eradicating cold-water species in temperate lakes. 相似文献
96.
Given the common use of self‐ratings and other‐ratings (e.g., supervisor or coworker) of organizational citizenship behavior (OCB), the purpose of this meta‐analysis was to evaluate the extent to which these rating sources provide comparable information. The current study's results provided three important lines of evidence supporting the use and construct‐related validity of self‐rated OCB. The meta‐analysis of mean differences demonstrated that the mean difference in OCB ratings is actually quite small between self‐ and other‐raters. Importantly, the difference between self‐ and other‐raters was influenced by neither the response scale (i.e., agreement vs. frequency) nor the use of antithetical/reverse‐worded items on OCB scales. The meta‐analysis of correlations showed that self‐ and other‐ratings are moderately correlated but that self–other convergence is higher when antithetical items are not used and when agreement response scales are used. In addition, self‐ratings and supervisor‐ratings showed significantly more convergence than self‐ratings and coworker‐ratings. Finally, an evaluation of self‐rated and other‐rated OCB nomological networks showed that although self‐rated and other‐rated OCBs have similar patterns of relationships with common correlates, other‐rated OCB generally contributed negligible incremental variance to correlates and only contributed appreciable incremental variance to other‐rated behavioral variables (e.g., task performance and counterproductive work behavior). Implications and future research directions are discussed, particularly regarding the need to establish a nomological network for other‐rated OCB. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
97.
Carol Carpenter 《Natural resources forum》2001,25(1):11-19
The thesis in this article is that both women's work and its invisibility are essential to development, and at two levels: to the economy of rural households and to the wider development process. For rural households, the case of Pakistan suggests that the veils that conceal women's work shield a portion of household production from the risks and extractions inherent in their involvement with development. This shielded production depends on off-farm natural resources of which the use is also veiled. For States and other development interests, the author suggests that women's work constitutes a subsidy which is intentionally invisible. The subsidy of women's labour is linked to a forest-to-farm subsidy. Women's invisible work, in other words, is not invisible because it is not seen, but because the process of economic development—for both rural households and States and other development actors—requires that it be hidden. 相似文献
98.
Dubuc C Muniz L Heistermann M Engelhardt A Widdig A 《Behavioral ecology and sociobiology》2011,65(8):1615-1627
In mammals, when females are clumped in space, male access to receptive females is usually determined by a dominance hierarchy
based on fighting ability. In polygynandrous primates, as opposed to most mammalian species, the strength of the relationship
between male social status and reproductive success varies greatly. It has been proposed that the degree to which paternity
is determined by male rank decreases with increasing female reproductive synchrony. The priority-of-access model (PoA) predicts
male reproductive success based on female synchrony and male dominance rank. To date, most tests of the PoA using paternity
data involved nonseasonally breeding species. Here, we examine whether the PoA explains the relatively low reproductive skew
in relation to dominance rank reported in the rhesus macaque, a strictly seasonal species. We collected behavioral, genetic,
and hormonal data on one group of the free-ranging population on Cayo Santiago (Puerto Rico) for 2 years. The PoA correctly
predicted the steepness of male reproductive skew, but not its relationship to male dominance: the most successful sire, fathering
one third of the infants, was high but not top ranking. In contrast, mating success was not significantly skewed, suggesting
that other mechanisms than social status contributed to male reproductive success. Dominance may be less important for paternity
in rhesus macaques than in other primate species because it is reached through queuing rather than contest, leading to alpha
males not necessarily being the strongest or most attractive male. More work is needed to fully elucidate the mechanisms determining
paternity in rhesus macaques. 相似文献
99.
Early warning signals (EWS) of regime shifts are challenging in cases where the true natural data-generating process is uncertain. Nonparametric drift-diffusion-jump models address this problem by fitting a general model that can approximate a wide range of data-generating processes. Drift measures the local rate of change. Diffusion measures relatively small shocks that occur at each time step. Jumps are large intermittent shocks. Total variance combines the contributions of diffusion and jumps. Nonparametric methods are well suited to emerging technology for automated, high-frequency sensors. Total variance is the most precisely measured indicator. Jump intensity appears to be a useful EWS. Estimates of the drift are highly uncertain unless long time series with many regime shifts are available. EWS computed from drift estimates (such as autocorrelation coefficients or return rates) have low precision and should be used with caution. Nonetheless, in the current state of knowledge, it is premature to disregard any potential EWS. 相似文献
100.
Russell Jones Constance Travers Charles Rodgers Brian Lazar Eric English Joshua Lipton Jason Vogel Kenneth Strzepek Jeremy Martinich 《Mitigation and Adaptation Strategies for Global Change》2013,18(6):731-758
We estimated the biological and economic impacts of climate change on freshwater fisheries in the United States (U.S.). Changes in stream temperatures, flows, and the spatial extent of suitable thermal habitats for fish guilds were modeled for the coterminous U.S. using a range of projected changes in temperature and precipitation caused by increased greenhouse gases (GHGs). Based on modeled shifts in available thermal habitat for fish guilds, we estimated potential economic impacts associated with changes in freshwater recreational fishing using a national-scale economic model of recreational fishing behavior. In general, the spatial distribution of coldwater fisheries is projected to contract, being replaced by warm/cool water and high-thermally tolerant, lower recreational priority (i.e., “rough”) fisheries. Changes in thermal habitat suitability become more pronounced under higher emissions scenarios and at later time periods. Under the highest GHG emissions scenario, by year 2100 habitat for coldwater fisheries is projected to decline by roughly 50 % and be largely confined to mountainous areas in the western U.S. and very limited areas of New England and the Appalachians. The economic model projects a decline in coldwater fishing days ranging from 1.25 million in 2030 to 6.42 million by 2100 and that the total present value of national economic losses to freshwater recreational fishing from 2009 to 2100 could range from $81 million to $6.4 billion, depending on the emissions scenario and the choice of discount rate. 相似文献