全文获取类型
收费全文 | 265篇 |
免费 | 2篇 |
国内免费 | 3篇 |
专业分类
安全科学 | 6篇 |
废物处理 | 19篇 |
环保管理 | 17篇 |
综合类 | 50篇 |
基础理论 | 61篇 |
污染及防治 | 77篇 |
评价与监测 | 28篇 |
社会与环境 | 10篇 |
灾害及防治 | 2篇 |
出版年
2023年 | 5篇 |
2022年 | 10篇 |
2021年 | 9篇 |
2020年 | 8篇 |
2019年 | 5篇 |
2018年 | 8篇 |
2017年 | 5篇 |
2016年 | 13篇 |
2015年 | 11篇 |
2014年 | 13篇 |
2013年 | 26篇 |
2012年 | 21篇 |
2011年 | 21篇 |
2010年 | 8篇 |
2009年 | 18篇 |
2008年 | 9篇 |
2007年 | 14篇 |
2006年 | 19篇 |
2005年 | 13篇 |
2004年 | 6篇 |
2003年 | 7篇 |
2002年 | 8篇 |
2000年 | 3篇 |
1999年 | 3篇 |
1998年 | 3篇 |
1997年 | 1篇 |
1995年 | 1篇 |
1992年 | 1篇 |
1991年 | 1篇 |
排序方式: 共有270条查询结果,搜索用时 31 毫秒
261.
Daniela Canestrari Marta Vila José M. Marcos Vittorio Baglione 《Behavioral ecology and sociobiology》2012,66(9):1225-1235
In cooperatively breeding species, parents should bias offspring sex ratio towards the philopatric sex to obtain new helpers (helper repayment hypothesis). However, philopatric offspring might increase within-group competition for resources (local resource competition hypothesis), diluting the benefits of helper acquisition. Furthermore, benefits of offspring sex bias on parents’ fitness may depend on different costs of production and/or different breeding opportunities of sons and daughters. Because of these counteracting factors, strategies of offspring sex allocation in cooperative species are often difficult to investigate. In carrion crows Corvus corone corone in northern Spain, sons are more philopatric and more helpful at the nest than daughters, which disperse earlier and have higher chances to find a breeding vacancy. Consistent with the helper repayment hypothesis, we found that crows fledged more sons in groups short of subordinate males than in groups with sufficient helper contingent, where daughters were preferred. Crow females also proved able to bias primary sex ratio, allocating offspring sex along the hatching sequence in a way that provided the highest fledging probability to sons in the first breeding attempt and to daughters in the following ones. The higher cost of producing male offspring may explain this pattern, with breeding females shifting to the cheapest sex (female) as a response to the costs generated by previous reproductive attempts. Our results suggest complex adjustments of offspring sex ratio that allowed crows to maximize the value of daughters and sons. 相似文献
262.
Copepod grazing impact on planktonic communities has commonly been underestimated due to the lack of information on naupliar
feeding behaviour and ingestion rates. That is particularly true for small cyclopoid copepods, whose nauplii are mainly in
the microzooplankton size range (<200 μm). The trophic role of Oithona spp. nauplii was investigated off Concepción (central Chile, ~36°S) during the highly productive upwelling season, when maximum
abundances of these nauplii were expected. Diet composition, ingestion rates, and food-type preferences were assessed through
grazing experiments with different size fractions of natural planktonic assemblages (<3, <20, <100, and <125 μm) and cultures
of the nanoflagellate Isochrysis galbana. When the Oithona spp. nauplii were offered a wide range of size fractions as food (pico- to microplankton), they mostly ingested small (2–5 μm)
nanoflagellates (5–63 × 103 cells nauplius−1 day−1). No ingestion on microplankton was detected, and picoplankton was mainly ingested when it was the only food available. Daily
carbon (C) uptake by the nauplii ranged between 28 and 775 ng C nauplius−1, representing an overall mean of 378% of their body C. Our relatively high ingestion rate estimates can be explained by methodological
constraints in previous studies on naupliar feeding, including those dealing with “over-crowding” and “edge” effects. Overall,
the grazing impact of the Oithona spp. nauplii on the prey C standing stocks amounts up to 21% (average = 13%) for picoplankton and 54% (average = 28%) for
nanoplankton. These estimates imply that the nauplii of the most dominant cyclopoid copepods exert a significant control on
the abundances of nanoplankton assemblages and, thereby, represent an important trophic link between the classical and microbial
food webs in this coastal upwelling system. 相似文献
263.
Ni-MH spent batteries: a raw material to produce Ni-Co alloys 总被引:5,自引:0,他引:5
Ni-MH spent batteries are heterogeneous and complex materials, so any kind of metallurgical recovery process needs a mechanical pre-treatment at least to separate irony materials and recyclable plastic materials (like ABS) respectively, in order to get additional profit from this saleable scrap, as well as minimize waste arising from the braking separation process. Pyrometallurgical processing is not suitable to treat Ni-MH batteries mainly because of Rare Earths losses in the slag. On the other hand, the hydrometallurgical method, that offers better opportunities in terms of recovery yield and higher purity of Ni, Co, and RE, requires several process steps as shown in technical literature. The main problems during leach liquor purification are the removal of elements such as Mn, Zn, Cd, dissolved during the leaching step, and the separation of Ni from Co. In the present work, the latter problem is overcome by co-deposition of a Ni-35/40%w Co alloy of good quality. The experiments carried out in a laboratory scale pilot-plant show that a current efficiency higher than 91% can be reached in long duration electrowinning tests performed at 50 degrees C and 4.3 catholyte pH. 相似文献
264.
265.
Daniela Fottová 《Environmental monitoring and assessment》1995,34(2):215-221
Monitoring of element flows and their mass balances in the natural unit of the biosphere represented by a small catchment appears to be the most suitable for the solution of complex problems such as the deterioration of environmental quality. Long-term collection of comparable biogeochemical data, which will enable the identification of environmental trends, is the main aim of the GEOMON network. One of the most important applications of these data will be the calculation of critical loads. The Czech Geological Survey possesses data from 44 catchments in the former Czechoslovakia. Qualitative and quantitative data on inputs in atmospheric deposition and outputs via surface runoff are available. Simple input-output mass balances yield estimates of total accumulation or loss of individual components. Some examples of interpretations of the GEOMON data, especially in connection with different bedrock types, will be given. 相似文献
266.
Stefano Colazza Mauro Lo Bue Daniela Lo Giudice Ezio Peri 《Die Naturwissenschaften》2009,96(8):975-981
Chemical footprints left behind by true bugs are perceived as contact kairomones by scelionid egg parasitoids. Female wasps
encountering a contaminated artificial substrate display a characteristic arrestment posture, holding the body motionless
and antennating the surface. In the system Nezara viridula (L.) and its egg parasitoid Trissolcus basalis (Wollaston), previous studies have shown that the kairomone mediating such behavior is part of N. viridula’s cuticular hydrocarbons (CHC) and furthermore that the wasp’s ability to discriminate host male and female footprints is mainly
based on the presence/absence of nonadecane (nC19). In this study, the effect of epicuticular waxes of leaves of broad bean, Vicia faba, on wasp responses to footprints of N. viridula females were investigated. Approximately 20% of T. basalis females displayed an arrestment posture when released on the adaxial leaf surfaces of broad bean plants with intact wax layer
and without host chemical contamination; whereas ∼70% of wasps displayed the arrestment posture when intact leaves were contaminated
by host female footprints. Adaxial leaf surfaces of broad bean plants dewaxed with an aqueous solution of gum arabic and afterwards
contaminated by N. viridula females induced arrestment responses in about 10% of female wasps; the same percentage of arrestment (10%) was observed when
the wasps were released on leaves contaminated by host females and subsequently dewaxed. The side of the polymer film that
was appressed to the leaf surface, peeled from the contaminated leaves, induced an arrestment posture in about 95% of observed
wasps. Scanning electron microscopy (SEM) revealed that the epicuticular waxes occurred as a film densely crystallized as
irregularly shaped platelets with spherical granules randomly distributed. These findings demonstrated that epicuticular waxes
of broad bean leaves can mediate the foraging behavior of T. basalis females by absorbing contact kairomones of the host. 相似文献
267.
Pedroso Thays Millena Alves Benvindo-Souza Marcelino de Araújo Nascimento Felipe Woch Júlia dos Reis Fabiana Gonçalves de Melo e Silva Daniela 《Environmental science and pollution research international》2022,29(12):17464-17475
Environmental Science and Pollution Research - Occupational exposure to pesticides has been identified as a major trigger of the development of cancer. Pesticides can cause intoxication in the... 相似文献
268.
Bendix Phillip Achenbach Hermann Weihaupt Petra Eckert Daniela Oehme Ines Berg Holger 《Journal of Material Cycles and Waste Management》2022,24(4):1432-1443
Journal of Material Cycles and Waste Management - The construction sector is the second largest area for the application for plastics. Due to the long life times of construction products, the... 相似文献
269.
Jara Marcia Daniela Lazo Alvarez Luis Alberto Contreras Guimarães Marco C. C. Antunes Paulo Wagnner Pereira de Oliveira Jairo Pinto 《Environmental science and pollution research international》2022,29(31):46487-46508
Environmental Science and Pollution Research - Devices based on lateral flow assay (LFA) have been gaining more and more space in the detection market mainly due to their simplicity, speed, and low... 相似文献
270.
Slow pyrolysis of olive mill solid residues as a sustainable valorization strategy for waste biomass
Piscitelli Lea Rasse Daniel P. Malerba Anna Daniela Miano Teodoro Mondelli Donato 《Journal of Material Cycles and Waste Management》2023,25(3):1688-1698
Journal of Material Cycles and Waste Management - Pyrolysis is a valid thermos-chemical process of energy production that produces biochar from potentially harmful biomasses. This study aims to... 相似文献