全文获取类型
收费全文 | 171篇 |
免费 | 0篇 |
专业分类
安全科学 | 5篇 |
环保管理 | 27篇 |
基础理论 | 122篇 |
污染及防治 | 6篇 |
评价与监测 | 2篇 |
灾害及防治 | 9篇 |
出版年
2015年 | 1篇 |
2014年 | 9篇 |
2013年 | 11篇 |
2012年 | 1篇 |
2011年 | 6篇 |
2010年 | 12篇 |
2009年 | 13篇 |
2008年 | 5篇 |
2007年 | 13篇 |
2006年 | 8篇 |
2005年 | 14篇 |
2004年 | 16篇 |
2003年 | 6篇 |
2002年 | 1篇 |
2001年 | 7篇 |
1999年 | 1篇 |
1997年 | 9篇 |
1996年 | 4篇 |
1995年 | 6篇 |
1993年 | 5篇 |
1992年 | 1篇 |
1991年 | 3篇 |
1990年 | 3篇 |
1989年 | 2篇 |
1988年 | 4篇 |
1987年 | 1篇 |
1986年 | 1篇 |
1983年 | 1篇 |
1981年 | 2篇 |
1980年 | 2篇 |
1978年 | 1篇 |
1977年 | 2篇 |
排序方式: 共有171条查询结果,搜索用时 849 毫秒
101.
Researchers have noted that upward influence tactics are often used in varying patterns and combinations (e.g. Yukl and Falbe, 1990). This study investigated whether influence strategies representing hard, soft, or rational approaches to influence behavior would emerge in relation to upward influence tactics of assertiveness, rationality, coalition, upward appeal, ingratiation, and exchange. Hypotheses were offered concerning the relations of selected demographic, individual difference, relational, and opportunity factors to these strategies. The 225 participants were full-time employees of a national non-profit organization. Second-order factor analysis provided some support for the dimensionalization of upward influence tactics as representing hard, soft, and rational strategies. Each strategy was related to a unique set of predictors. The results suggest a higher level of complexity for influence strategies than previously expected. The implications of this study, as well as fruitful areas for future research, are discussed. © 1997 John Wiley & Sons, Ltd. 相似文献
102.
JOHN ZACHARIAS 《Journal of environmental psychology》2001,21(4):341
This paper is concerned with the exploratory behaviour of first-time visitors to an environment and specifically with the importance of visual stimuli in path choice. Forty-five participants were asked to select among photos representing the path choices at 13 street intersections in the historic centre of Montpellier, providing reasons as they proceeded. Preference among choices at intersections varied significantly in 10 of 13 cases. Eight intersections with the greatest differences in preference between choices were modified such that persons, signs, planters and awnings were removed from the most preferred scenes and inserted into the least preferred. The virtual tour was run again with a new group of participants. In comparison with the first group, the second expressed greater preference for path choices with added elements and diminished preference for photos with removed elements. Choices were also related to verbalizations and rated architectural properties. 相似文献
103.
Criteria for Oil Spill Recovery: A Case Study of the Intertidal Community of Prince William Sound, Alaska, Following the Exxon Valdez Oil Spill 总被引:1,自引:0,他引:1
Marine intertidal organisms in Prince William Sound were exposed to crude oil following the T/V Exxon Valdez oil spill in 1989. The intertidal communities were also subjected to mechanical disturbance during invasive oil spill remediation
and cleanup efforts. Using monitoring data collected from 1989 to 1997, impacts and eventual recovery were assessed at oiled
but uncleaned sites and oiled and cleaned study areas. A statistical model where recovery was defined as parallelism between
the time profiles at control and oiled sites was evaluated. Statistical analysis and graphical presentations of the data suggest
intertidal epibiota communities recovered from the oil spill by 1992 at the oiled sites and by 1994 at the oiled and remediated
sites. Empirical data from the intertidal monitoring program supports the use of tests of parallelism in evaluating recovery
and the need to avoid simply the comparison of sample means from control and oiled sites. 相似文献
104.
KEVIN M. BROWN R. MICHAEL ERWIN MILO E. RICHMOND P. A. BUCKLEY JOHN T. TANACREDI DAVE AVRIN 《Environmental management》2001,28(2):207-224
During the 1980s, the exponential growth of laughing gull (Larus atricilla) colonies, from 15 to about 7600 nests in 1990, in the Jamaica Bay Wildlife Refuge and a correlated increase in the bird-strike
rate at nearby John F. Kennedy International Airport (New York City) led to a controversy between wildlife and airport managers
over the elimination of the colonies. In this paper, we review data to evaluate if: (1) the colonies have increased the level
of risk to the flying public; (2) on-colony population control would reduce the presence of gulls, and subsequently bird strikes,
at the airport; and (3) all on-airport management alternatives have been adequately implemented. Since 1979, most (2987, 87%)
of the 3444 bird strikes (number of aircraft struck) were actually bird carcasses found near runways (cause of death unknown
but assumed to be bird strikes by definition). Of the 457 pilot-reported strikes (mean = 23 ± 6 aircraft/yr, N= 20 years), 78 (17%) involved laughing gulls. Since a gull-shooting program was initiated on airport property in 1991, over
50,000 adult laughing gulls have been killed and the number of reported bird strikes involving laughing gulls has declined
from 6.9 ± 2.9 (1983–1990) to 2.6 ± 1.3 (1991–1998) aircraft/yr; nongull reported bird strikes, however, have more than doubled
(6.4 ± 2.6, 1983–1990; 14.9 ± 5.1, 1991–1998). We found no evidence to indicate that on-colony management would yield a reduction
of bird strikes at Kennedy Airport. Dietary and mark–recapture studies suggest that 60%–90% of the laughing gulls collected
on-airport were either failed breeders and/or nonbreeding birds. We argue that the Jamaica Bay laughing gull colonies, the
only ones in New York State, should not be managed at least until all on-airport management alternatives have been properly
implemented and demonstrated to be ineffective at reducing bird strikes, including habitat alterations and increasing the
capability of the bird control unit to eliminate bird flocks on-airport using nonlethal bird dispersal techniques. Because
the gull-shooting program may be resulting in a nonsustainable regional population of laughing gulls (>30% decline), we also
recommend that attempts be made to initiate an experimental colony elsewhere on Long Island to determine if colony relocation
is a feasible management option. 相似文献
105.
JOEL BERGER STEVEN L. CAIN ELLEN CHENG PETER DRATCH KEVIN ELLISON JOHN FRANCIS HERBERT C. FROST SCOTT GENDE CRAIG GROVES WILLIAM A. KARESH ELAINE LESLIE GARY MACHLIS RODRIGO A. MEDELLIN REED F. NOSS KENT H. REDFORD MICHAEL SOUKUP DAVID WILCOVE STEVE ZACK 《Conservation biology》2014,28(1):4-12
Public agencies sometimes seek outside guidance when capacity to achieve their mission is limited. Through a cooperative agreement and collaborations with the U.S. National Park Service (NPS), we developed recommendations for a conservation program for migratory species. Although NPS manages ~36 million hectares of land and water in 401 units, there is no centralized program to conserve wild animals reliant on NPS units that also migrate hundreds to thousands of kilometers beyond parks. Migrations are imperiled by habitat destruction, unsustainable harvest, climate change, and other impediments. A successful program to counter these challenges requires public support, national and international outreach, and flourishing migrant populations. We recommended two initial steps. First, in the short term, launch or build on a suite of projects for high‐profile migratory species that can serve as proof to demonstrate the centrality of NPS units to conservation at different scales. Second, over the longer term, build new capacity to conserve migratory species. Capacity building will entail increasing the limited knowledge among park staff about how and where species or populations migrate, conditions that enable migration, and identifying species’ needs and resolving them both within and beyond parks. Building capacity will also require ensuring that park superintendents and staff at all levels support conservation beyond statutory borders. Until additional diverse stakeholders and a broader American public realize what can be lost and do more to protect it and engage more with land management agencies to implement actions that facilitate conservation, long distance migrations are increasingly likely to become phenomena of the past. Optimismo y Retos para la Conservación Científicamente Basada de Especies Migratorias Dentro y Fuera de Parques Nacionales de E.U.A. 相似文献
106.
MICHAEL A. MCCARTHY ALANA L. MOORE JOCHEN KRAUSS JOHN W. MORGAN CHRISTOPHER F. CLEMENTS 《Conservation biology》2014,28(6):1575-1583
Biodiversity indices often combine data from different species when used in monitoring programs. Heuristic properties can suggest preferred indices, but we lack objective ways to discriminate between indices with similar heuristics. Biodiversity indices can be evaluated by determining how well they reflect management objectives that a monitoring program aims to support. For example, the Convention on Biological Diversity requires reporting about extinction rates, so simple indices that reflect extinction risk would be valuable. We developed 3 biodiversity indices that are based on simple models of population viability that relate extinction risk to abundance. We based the first index on the geometric mean abundance of species and the second on a more general power mean. In a third index, we integrated the geometric mean abundance and trend. These indices require the same data as previous indices, but they also relate directly to extinction risk. Field data for butterflies and woodland plants and experimental studies of protozoan communities show that the indices correlate with local extinction rates. Applying the index based on the geometric mean to global data on changes in avian abundance suggested that the average extinction probability of birds has increased approximately 1% from 1970 to 2009. Conectando Índices para el Monitoreo de la Biodiversidad con la Teoría de Riesgo de Extinción 相似文献
107.
ERIK A. BEEVER BRADY J. MATTSSON MATTHEW J. GERMINO MAX POST VAN DER BURG JOHN B. BRADFORD MARK W. BRUNSON 《Conservation biology》2014,28(2):302-314
Integration of conservation partnerships across geographic, biological, and administrative boundaries is increasingly relevant because drivers of change, such as climate shifts, transcend these boundaries. We explored successes and challenges of established conservation programs that span multiple watersheds and consider both social and ecological concerns. We asked representatives from a diverse set of 11 broad‐extent conservation partnerships in 29 countries 17 questions that pertained to launching and maintaining partnerships for broad‐extent conservation, specifying ultimate management objectives, and implementation and learning. Partnerships invested more funds in implementing conservation actions than any other aspect of conservation, and a program's context (geographic extent, United States vs. other countries, developed vs. developing nation) appeared to substantially affect program approach. Despite early successes of these organizations and benefits of broad‐extent conservation, specific challenges related to uncertainties in scaling up information and to coordination in the face of diverse partner governance structures, conflicting objectives, and vast uncertainties regarding future system dynamics hindered long‐term success, as demonstrated by the focal organizations. Engaging stakeholders, developing conservation measures, and implementing adaptive management were dominant challenges. To inform future research on broad‐extent conservation, we considered several challenges when we developed detailed questions, such as what qualities of broad‐extent partnerships ensure they complement, integrate, and strengthen, rather than replace, local conservation efforts and which adaptive management processes yield actionable conservation strategies that account explicitly for dynamics and uncertainties regarding multiscale governance, environmental conditions, and knowledge of the system? Éxitos y Retos de la Formación a la Implementación de Once Programas de Conservación de Amplio Alcance 相似文献
108.
109.
110.
JOHN E. FA MIGUEL ANGEL FARFÁN ANA LUZ MARQUEZ JESÚS DUARTE JANET NACKONEY AMY HALL JEF DUPAIN SARAH SEYMOUR PAUL J. JOHNSON DAVID W. MACDONALD J. MARIO VARGAS 《Conservation biology》2014,28(1):224-233
Bushmeat markets exist in many countries in West and Central Africa, and data on species sold can be used to detect patterns of wildlife trade in a region. We surveyed 89 markets within the Cross–Sanaga rivers region, West Africa. In each market, we counted the number of carcasses of each taxon sold. During a 6‐month period (7594 market days), 44 mammal species were traded. Thirteen species were on the International Union for Conservation of Nature (IUCN) Red List or protected under national legislation, and at least 1 threatened species was traded in 88 of the 89 markets. We used these data to identify market groups that traded similar species assemblages. Using cluster analyses, we detected 8 market groups that were also geographically distinct. Market groups differed in the diversity of species, evenness of species, and dominant, prevalent, and characteristic species traded. We mapped the distribution of number of threatened species traded across the study region. Most threatened species were sold in markets nearest 2 national parks, Korup National Park in Cameroon and Cross River in Nigeria. To assess whether the threatened‐species trade hotspots coincided with the known ranges of these species, we mapped the overlap of all threatened species traded. Markets selling more threatened species overlapped with those regions that had higher numbers of these. Our study can provide wildlife managers in the region with better tools to discern zones within which to focus policing efforts and reduce threats to species that are threatened by the bushmeat trade. Mapeo de Sitios Críticos para Especies Amenazadas Comercializadas en Mercados de Vida Silvestre en la Región de los Ríos Cross‐Sanaga 相似文献