全文获取类型
收费全文 | 305篇 |
免费 | 11篇 |
国内免费 | 5篇 |
专业分类
安全科学 | 9篇 |
废物处理 | 16篇 |
环保管理 | 47篇 |
综合类 | 79篇 |
基础理论 | 73篇 |
污染及防治 | 71篇 |
评价与监测 | 12篇 |
社会与环境 | 9篇 |
灾害及防治 | 5篇 |
出版年
2023年 | 6篇 |
2022年 | 13篇 |
2021年 | 20篇 |
2020年 | 12篇 |
2019年 | 11篇 |
2018年 | 19篇 |
2017年 | 10篇 |
2016年 | 19篇 |
2015年 | 6篇 |
2014年 | 14篇 |
2013年 | 16篇 |
2012年 | 14篇 |
2011年 | 22篇 |
2010年 | 12篇 |
2009年 | 18篇 |
2008年 | 11篇 |
2007年 | 10篇 |
2006年 | 12篇 |
2005年 | 9篇 |
2004年 | 6篇 |
2003年 | 11篇 |
2002年 | 11篇 |
2001年 | 8篇 |
2000年 | 3篇 |
1999年 | 1篇 |
1998年 | 4篇 |
1996年 | 4篇 |
1995年 | 1篇 |
1994年 | 4篇 |
1993年 | 1篇 |
1992年 | 1篇 |
1990年 | 2篇 |
1988年 | 1篇 |
1984年 | 1篇 |
1983年 | 1篇 |
1981年 | 2篇 |
1979年 | 2篇 |
1976年 | 1篇 |
1974年 | 1篇 |
1973年 | 1篇 |
排序方式: 共有321条查询结果,搜索用时 15 毫秒
51.
Honeybees, Apis spp., maintain elevated temperatures inside their nests to accelerate brood development and to facilitate defense against predators.
We present an additional defensive function of elevating nest temperature: honeybees generate a brood-comb fever in response
to colonial infection by the heat-sensitive pathogen Ascosphaera apis. This response occurs before larvae are killed, suggesting that either honeybee workers detect the infection before symptoms
are visible, or that larvae communicate the ingestion of the pathogen. This response is a striking example of convergent evolution
between this "superorganism" and other fever-producing animals.
Received: 2 September 1999 / Accepted in revised form: 28 February 2000 相似文献
52.
Russell?Alpizar-JaraEmail author Kenneth?H.?Pollock Dawn?E.?Haines 《Environmental and Ecological Statistics》2005,12(2):155-168
The combined mark-recapture and line transect sampling methodology proposed by Alpizar-Jara and Pollock [Journal of Environmental and Ecological Statistics, 3(4), 311–327, 1996; In Marine Mammal Survey and Assessment Methods Symposium. G.W. Garner, S.C. Amstrup, J.L. Laake, B.F.J. Manly, L.L. McDonald, and D.C. Robertson (Eds.), A.A. Balkema, Rotterdam, Netherlands, pp. 99–114, 1999] is used to illustrate the estimation of population size for populations with prominent nesting structures (i.e., bald eagle nests). In the context of a bald eagle population, the number of nests in a list frame corresponds to a pre-marked sample of nests, and an area frame corresponds to a set of transect strips that could be regularly monitored. Unlike previous methods based on dual frame methodology using the screening estimator [Haines and Pollock (Journal of Environmental and Ecological Statistics, 5, 245–256, 1998a; Survey Methodology, 24(1), 79–88, 1998b)], we no longer need to assume that the area frame is complete (i.e., all the nests in the sampled sites do not need to be seen). One may use line transect sampling to estimate the probability of detection in a sampled area. Combining information from list and area frames provides more efficient estimators than those obtained by using data from only one frame. We derive an estimator for detection probability and generalize the screening estimator. A simulation study is carried out to compare the performance of the Chapman modification of the Lincoln–Petersen estimator to the screening estimator. Simulation results show that although the Chapman estimator is generally less precise than the screening estimator, the latter can be severely biased in presence of uncertain detection. The screening estimator outperforms the Chapman estimator in terms of mean squared error when detection probability is near 1 wheareas the Chapman estimator outperforms the screening estimator when detection probability is lower than a certain threshold value depending on particular scenarios. 相似文献
53.
54.
Thays de Andrade Guedes Cristina Moreira-de-Sousa Hellen Maria Soares Lima Tatiane Caroline Grella Priscila Cintra Socolowski Carmem Silvia Fontanetti 《Journal of environmental science and health. Part. B》2020,55(8):687-693
AbstractThe objective of this research was to investigate the potential damage caused by the residual concentrations of the insecticides Regent® WS 800 and Curbix® SC 200, containing fipronil and ethiprole, respectively as active ingredients, on the liver of Oreochromis niloticus. The analyses of HSP70 shock protein labelling and cell death process by TUNEL method were performed in order to measure the effects of the exposure of cell repair system of fish to both insecticides. Statistical analyses showed no significant molecular damage to the hepatic tissue of animals. Nevertheless, variations in HSP70 and DNA fragmentation levels, endpoint of cell repair system response and cellular death, respectively, were observed in several groups. These results indicate that the cell repair machinery was efficient when in contact with residual concentrations of insecticides. However, the DNA fragmentation detected by the TUNEL method suggests that even in face of the cytoprotective action of the HSP70 protein, there are damages that become irreparable. To finish, it is worth mentioning that given the results obtained from residual concentrations, use in the field should be with caution. 相似文献
55.
Caroline S. Chaboo Michael S. Engel Maria Lourdes Chamorro-Lacayo 《Die Naturwissenschaften》2009,96(9):1121-1126
Complex ethological adaptations and intraspecific interactions leave few fossil traces. We document three Dominican (20 million
years old [myo]) and Baltic (45 myo) amber fossils that exhibit firm evidence of highly integrated interactions between mothers
and offspring in the diverse camptosomate lineage of beetles (Chrysomelidae, leaf beetles). As in contemporary species, these
hard cases were initially constructed by mothers, then inherited and retained by offspring, which then elaborate this protective
domicile with an unusual but economical building material, their feces. The three fossils are classified in the Subfamily
Cryptocephalinae; two are classified in the tribe Chlamisini based on morphological evidence—the flattened head lacking a
sharp keel and long legs with simple recurved untoothed claws. These diagnostic features are not clearly visible in the third
specimen to permit more refined identification. These fossils provide more precise paleontological dating of tribal nodes
within the cryptocephaline radiation of leaf beetles. These fossils are the first and earliest evidence of mother–offspring
interaction, building behavior, and fecal recycling in Camptosomata beetles and of inheritance of architectural structures
in beetles. 相似文献
56.
Rajeh Caroline Saoud Imad P. Kharroubi Samer Naalbandian Salpy Abiad Mohamad G. 《Journal of Material Cycles and Waste Management》2021,23(1):1-17
Journal of Material Cycles and Waste Management - While society struggles to meet increasing food demand and mitigate food security challenges, approximately one-third of the food produced globally... 相似文献
57.
Endale DM Fisher DS Owens LB Jenkins MB Schomberg HH Tebes-Stevens CL Bonta JV 《Journal of environmental quality》2011,40(3):969-979
Approximately 11% of the Southern Piedmont (1.8 million ha) is used for pasture and hay production, mostly under low-input management. Few studies have investigated in the region long-term nitrogen and carbon losses in surface runoff, which can be significant. We present 1999 to 2009 hydrologic and water quality data from a rotationally grazed, 7.8-ha, zero-order pasture (W1) near Watkinsville in the Georgia Piedmont. Annual rainfall was 176 to 463 mm below the long-term average (1240 mm) in 7 of the 11 yr. There were 20 runoff events during 86 mo of below-average rainfall (deficit period), compared with 54 events during 46 mo of nondeficit period. Mean event flow-weighted concentration (in mg L) was 0.96 for nitrate-nitrogen (NO-N), 0.97 for ammonium-nitrogen (NH-N), 3.70 for total nitrogen (TN), and 9.12 for total organic carbon (TOC) ( = 43-47; limited due to instrument problem). Nutrient loads (in kg ha per event) averaged 0.04 for NO-N, 0.03 for NH-N, 0.19 for TN, and 0.54 for TOC. Total loads for N and TOC were 6 to 11 times greater from nondeficit than from deficit periods. The observed N concentrations, while well below maximum drinking water standard limits, could pose risk for eutrophication, which can be stimulated at lower concentrations. However, the ability of headwater streams, such as the one downstream of W1, to reduce nutrient concentrations might partially alleviate this concern. The results of this study point to the need to use a long-term dataset that includes measurements made in drought and wet years when evaluating the efficacy of water quality standards. 相似文献
58.
Razafimahefa Ravo M. Ludwig-Begall Louisa F. Diallo Mamadou Amadou Dewals Benjamin G. Vanderplasschen Alain Nivelles Olivier Deketelaere Caroline Mauroy Axel Thiry Etienne 《Food and environmental virology》2021,13(4):493-506
Food and Environmental Virology - Human noroviruses impose a considerable health burden globally. Here, a flow cytometry approach designed for their detection in biological waste and food samples... 相似文献
59.
Kristoffer Hylander Caroline Greiser Ditte M. Christiansen Irena A. Koelemeijer 《Conservation biology》2022,36(3):e13847
Conservation of biodiversity in managed forest landscapes needs to be complemented with new approaches given the threat from rapid climate change. Most frameworks for adaptation of biodiversity conservation to climate change include two major strategies. The first is the resistance strategy, which focuses on actions to increase the capacity of species and communities to resist change. The second is the transformation strategy and includes actions that ease the transformation of communities to a set of species that are well adapted to the novel environmental conditions. We suggest a number of concrete actions policy makers and managers can take. Under the resistance strategy, five tools are introduced, including: identifying and protecting forest climate refugia with cold-favored species; reducing the effects of drought by protecting the hydrological network; and actively removing competitors when they threaten cold-favored species. Under the transformation strategy, we suggest three tools, including: enhancing conditions for forest species favored by the new climate, but currently disfavored by forest management, by planting them at suitable sites outside their main range; and increasing connectivity across the landscape to enhance the expansion of warm-favored species to sites that have become suitable. Finally, we suggest applying a landscape perspective and simultaneously managing for both retreating and expanding species. The two different strategies (resistance and transformation) should be seen as complementary ways to maintain a rich biodiversity in future forest ecosystems. 相似文献
60.
Gardia-Parège Caroline Kim Tiam Sandra Budzinski Hélène Mazzella Nicolas Devier Marie-Hélène Morin Soizic 《Environmental science and pollution research international》2022,29(20):29368-29381
Environmental Science and Pollution Research - Effect-directed analysis (EDA) aims at identifying the compound(s) responsible for toxicity in a complex environmental sample where several dozens of... 相似文献