全文获取类型
收费全文 | 1492篇 |
免费 | 47篇 |
国内免费 | 23篇 |
专业分类
安全科学 | 61篇 |
废物处理 | 66篇 |
环保管理 | 324篇 |
综合类 | 125篇 |
基础理论 | 474篇 |
环境理论 | 4篇 |
污染及防治 | 299篇 |
评价与监测 | 106篇 |
社会与环境 | 83篇 |
灾害及防治 | 20篇 |
出版年
2023年 | 11篇 |
2022年 | 25篇 |
2021年 | 33篇 |
2020年 | 26篇 |
2019年 | 30篇 |
2018年 | 38篇 |
2017年 | 51篇 |
2016年 | 56篇 |
2015年 | 51篇 |
2014年 | 53篇 |
2013年 | 130篇 |
2012年 | 71篇 |
2011年 | 120篇 |
2010年 | 71篇 |
2009年 | 87篇 |
2008年 | 103篇 |
2007年 | 94篇 |
2006年 | 77篇 |
2005年 | 56篇 |
2004年 | 56篇 |
2003年 | 51篇 |
2002年 | 33篇 |
2001年 | 15篇 |
2000年 | 15篇 |
1999年 | 20篇 |
1998年 | 15篇 |
1997年 | 14篇 |
1996年 | 18篇 |
1995年 | 13篇 |
1994年 | 18篇 |
1993年 | 13篇 |
1992年 | 15篇 |
1991年 | 8篇 |
1990年 | 5篇 |
1989年 | 8篇 |
1988年 | 6篇 |
1987年 | 3篇 |
1986年 | 5篇 |
1985年 | 2篇 |
1984年 | 3篇 |
1983年 | 7篇 |
1982年 | 6篇 |
1981年 | 6篇 |
1980年 | 7篇 |
1978年 | 4篇 |
1976年 | 2篇 |
1975年 | 3篇 |
1973年 | 2篇 |
1959年 | 1篇 |
1957年 | 1篇 |
排序方式: 共有1562条查询结果,搜索用时 515 毫秒
921.
We compared the nesting success of a disturbance-dependent species, the Indigo Bunting ( Passerina cyanea), on different kinds of habitat edges in five sites (225 total nests) in southern Illinois from 1989 to 1993. Nest predation rates along agricultural and abrupt, permanent edges (e.g., wildlife openings, campgrounds) were nearly twice as high as rates along more gradual edges where plant succession was allowed to occur (e.g., treefalls, streamsides, gaps created by selective logging ). Levels of brood parasitism by Brown-headed Cowbirds ( Molothrus ater) varied significantly among sites and years, but not among edge types. Clutch sizes, however, were significantly smaller at agricultural edges where nest predation rates were also high, which suggests either decreased food availability or a population dominated by younger and/or lower-quality ( poor condition) birds. The results of this study illustrate the need to reevaluate management practices (e.g., wildlife openings) that are designed to promote populations of disturbance-dependent wildlife. 相似文献
922.
Singer AC Bell T Heywood CA Smith JA Thompson IP 《Environmental pollution (Barking, Essex : 1987)》2007,147(1):74-82
In this study we examine the effects of polycyclic aromatic hydrocarbons (PAHs) on the ability of the hyperaccumulator plant Alyssum lesbiacum to phytoextract nickel from co-contaminated soil. Planted and unplanted mesocosms containing the contaminated soils were repeatedly amended with sorbitan trioleate, salicylic acid and histidine in various combinations to enhance the degradation of two PAHs (phenanthrene and chrysene) and increase nickel phytoextraction. Plant growth was negatively affected by PAHs; however, there was no significant effect on the phytoextraction of Ni per unit biomass of shoot. Exogenous histidine did not increase nickel phytoextraction, but the histidine-extractable fraction of soil nickel showed a high correlation with phytoextractable nickel. These results indicate that Alyssum lesbiacum might be effective in phytoextracting nickel from marginally PAH-contaminated soils. In addition, we provide evidence for the broader applicability of histidine for quantifying and predicting Ni phytoavailability in soils. 相似文献
923.
The concentrations of organochlorine pesticide residues were determined in roots and leaves of giant sedges (Cyperus exaltatus), fresh leaves and dry hay of guinea grasses (Panicum maximum), and in stems and leaves of elephant grasses (Pennisetum purpureum) in the vicinity of a point source of contamination, an old storage site at Vikuge farm in Tanzania. The GPC-cleaned extracts were analyzed by GC-ECD and GC/MS. The concentrations of total DDT ranged from 83 to 18274 ng/g, 166 to 7922 ng/g, and 68 to 405 ng/g, on fresh weight basis, in C. exaltatus, P. maximum and P. purpureum, respectively. The concentrations of total HCH were up to 74 ng/gfw in leaves of C. exaltatus, 43 ng/gdw in dry hay of P. maximum, and 10 ng/gfw in stems of P. purpureum. Aldrin and dieldrin were only detected in C. exaltatus and their concentrations were up to 11 and 8 ng/gfw, respectively. The strong positive correlations between the concentrations of the detected compounds suggest a common source. The concentrations of total DDT were far above the Australian extraneous maximum residue limit in primary animal feedstuffs. These findings indicate potential risks and concerns for livestock and public health. The concentrations of aldrin, dieldrin and lindane were lower than the Australian limits. 相似文献
924.
Aderibigbe Abiodun D. Stewart Alex G. Hursthouse Andrew S. 《Environmental geochemistry and health》2018,40(1):395-413
Environmental Geochemistry and Health - A multidisciplinary approach to research affords the opportunity of objectivity, creation of new knowledge and potentially a more generally acceptable... 相似文献
925.
Species composition of the international shark fin trade assessed through a retail‐market survey in Hong Kong
下载免费PDF全文
![点击此处可从《Conservation biology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Andrew T. Fields Gunter A. Fischer Stanley K. H. Shea Huarong Zhang Debra L. Abercrombie Kevin A. Feldheim Elizabeth A. Babcock Demian D. Chapman 《Conservation biology》2018,32(2):376-389
The shark fin trade is a major driver of shark exploitation in fisheries all over the world, most of which are not managed on a species‐specific basis. Species‐specific trade information highlights taxa of particular concern and can be used to assess the efficacy of management measures and anticipate emerging threats. The species composition of the Hong Kong Special Administrative Region of China, one of the world's largest fin trading hubs, was partially assessed in 1999–2001. We randomly selected and genetically identified fin trimmings (n = 4800), produced during fin processing, from the retail market of Hong Kong in 2014–2015 to assess contemporary species composition of the fin trade. We used nonparametric species estimators to determine that at least 76 species of sharks, batoids, and chimaeras supplied the fin trade and a Bayesian model to determine their relative proportion in the market. The diversity of traded species suggests species substitution could mask depletion of vulnerable species; one‐third of identified species are threatened with extinction. The Bayesian model suggested that 8 species each comprised >1% of the fin trimmings (34.1–64.2% for blue [Prionace glauca], 0.2–1.2% for bull [Carcharhinus leucas] and shortfin mako [Isurus oxyrinchus]); thus, trade was skewed to a few globally distributed species. Several other coastal sharks, batoids, and chimaeras are in the trade but poorly managed. Fewer than 10 of the species we modeled have sustainably managed fisheries anywhere in their range, and the most common species in trade, the blue shark, was not among them. Our study and approach serve as a baseline to track changes in composition of species in the fin trade over time to better understand patterns of exploitation and assess the effects of emerging management actions for these animals. 相似文献
926.
Zachary L. Robinson Donovan A. Bell Tashi Dhendup Gordon Luikart Andrew R. Whiteley Marty Kardos 《Conservation biology》2021,35(2):666-677
Augmenting gene flow is a powerful tool for the conservation of small, isolated populations. However, genetic rescue attempts have largely been limited to populations at the brink of extinction, in part due to concerns over negative outcomes (e.g., outbreeding depression). Increasing habitat fragmentation may necessitate more proactive genetic management. Broader application of augmented gene flow will, in turn, require rigorous evaluation to increase confidence and identify pitfalls in this approach. To date, there has been no assessment of best monitoring practices for genetic rescue attempts. We used genomically explicit, individual-based simulations to examine the effectiveness of common approaches (i.e., tests for increases in fitness, migrant ancestry, heterozygosity, and abundance) for determining whether genetic rescue or outbreeding depression occurred. Statistical power to detect the effects of gene flow on fitness was high (≥0.8) when effect sizes were large, a finding consistent with those from previous studies on severely inbred populations. However, smaller effects of gene flow on fitness can appreciably affect persistence probability but current evaluation approaches fail to provide results from which reliable inferences can be drawn. The power of the metrics we examined to evaluate genetic rescue attempts depended on the time since gene flow and whether gene flow was beneficial or deleterious. Encouragingly, the use of multiple metrics provided nonredundant information and improved inference reliability, highlighting the importance of intensive monitoring efforts. Further development of best practices for evaluating genetic rescue attempts will be crucial for a responsible transition to increased use of translocations to decrease extinction risk. 相似文献
927.
Henry Travers Lucy J. Archer Geoffrey Mwedde Dilys Roe Julia Baker Andrew J. Plumptre Aggrey Rwetsiba E.J. Milner-Gulland 《Conservation biology》2019,33(6):1296-1306
In conservation understanding the drivers of behavior and developing robust interventions to promote behavioral change is challenging and requires a multifaceted approach. This is particularly true for efforts to address illegal wildlife use, where pervasive—and sometimes simplistic—narratives often obscure complex realities. We used an indirect questioning approach, the unmatched count technique, to investigate the drivers and prevalence of wildlife crime in communities surrounding 2 national parks in Uganda and combined scenario interviews and a choice experiment to predict the performance of potential interventions designed to tackle these crimes. Although poverty is often assumed to be a key driver of wildlife crime, we found that better-off households and those subject to human–wildlife conflict and those that do not receive any benefits from the parks’ tourism revenue sharing were more likely to be involved in certain types of wildlife crime, especially illegal hunting. The interventions predicted to have the greatest impact on reducing local participation in wildlife crime were those that directly addressed the drivers including, mitigating damage caused by wildlife and generating financial benefits for park-adjacent households. Our triangulated approach provided insights into complex and hard-to-access behaviors and highlighted the importance of going beyond single-driver narratives. 相似文献
928.
Understanding and conserving mobile species presents complex challenges, especially for animals in stochastic or changing environments. Nomadic waterbirds must locate temporary water in arid biomes where rainfall is highly unpredictable in space and time. To achieve this they need to travel over vast spatial scales and time arrival to exploit pulses in food resources. How they achieve this is an enduring mystery. We investigated these challenges in the colonial‐nesting Banded Stilt (Cladorhynchus leucocephalus), a nomadic shorebird of conservation concern. Hitherto, Banded Stilts were hypothesized to have only 1–2 chances to breed during their long lifetime, when flooding rain fills desert salt lakes, triggering mass‐hatching of brine shrimp. Over 6 years, we satellite tagged 57 individuals, conducted 21 aerial surveys to detect nesting colonies on 14 Australian desert salt lakes, and analyzed 3 decades of Landsat and MODIS satellite imagery to quantify salt‐lake flood frequency and extent. Within days of distant inland rainfall, Banded Stilts flew 1,000–2,000 km to reach flooded salt lakes. On arrival, females laid over half their body weight in eggs. We detected nesting episodes across the species’ range at 7 times the frequency reported during the previous 80 years. Nesting colonies of thousands formed following minor floods, yet most were subsequently abandoned when the water rapidly evaporated prior to egg hatching. Satellite imagery revealed twice as many flood events sufficient for breeding‐colony initiation as recorded colonies, suggesting that nesting at remote sites has been underdetected. Individuals took risk on uncertain breeding opportunities by responding to frequent minor flood events between infrequent extensive flooding, exemplifying the extreme adaptability and trade‐offs of species exploiting unstable environments. The conservation challenges of nest predation by overabundant native gulls and anthropogenic modifications to salt lakes filling frequencies require investigation, as do the physiological and navigational mechanisms that enable such extreme strategies. 相似文献
929.
Kaninga Belinda Lark R. Murray Chishala Benson H. Maseka Kakoma K. Sakala Godfrey M. Young Scott D. Tye Andrew Hamilton Elliott M. Watts Michael J. 《Environmental geochemistry and health》2021,43(9):3699-3713
Environmental Geochemistry and Health - A field experiment was undertaken on farmers’ fields adjacent to a large mine tailings dam in the Zambian mining town of Kitwe. Experimental plots were... 相似文献
930.
Nicholas L. Ortodossi Ben L. Gilby Thomas A. Schlacher Rod M. Connolly Nicholas A. Yabsley Christopher J. Henderson Andrew D. Olds 《Conservation biology》2019,33(3):580-589
Seascape connectivity (landscape connectivity in the sea) can modify reserve performance in low-energy marine ecosystems (e.g., coral reefs, mangroves, and seagrass), but it is not clear whether similar spatial linkages also shape reserve effectiveness on high-energy, exposed coastlines. We used the surf zones of ocean beaches in eastern Australia as a model system to test how seascape connectivity and reserve attributes combine to shape conservation outcomes. Spatial patterns in fish assemblages were measured using baited remote underwater video stations in 12 marine reserves and 15 fished beaches across 2000 km of exposed coastline. Reserve performance was shaped by both the characteristics of reserves and the spatial properties of the coastal seascapes in which reserves were embedded. Number of fish species and abundance of harvested fishes were highest in surf-zone reserves that encompassed >1.5 km of the surf zone; were located < 100 m to rocky headlands; and included pocket beaches in a heterogeneous seascape. Conservation outcomes for exposed coastlines may, therefore, be enhanced by prioritizing sufficiently large areas of seascapes that are strongly linked to abutting complementary habitats. Our findings have broader implications for coastal conservation planning. Empirical data to describe how the ecological features of high-energy shorelines influence conservation outcomes are lacking, and we suggest that seascape connectivity may have similar ecological effects on reserve performance on both sheltered and exposed coastlines. 相似文献