全文获取类型
收费全文 | 630篇 |
免费 | 4篇 |
国内免费 | 7篇 |
专业分类
安全科学 | 31篇 |
废物处理 | 41篇 |
环保管理 | 79篇 |
综合类 | 90篇 |
基础理论 | 141篇 |
环境理论 | 3篇 |
污染及防治 | 185篇 |
评价与监测 | 40篇 |
社会与环境 | 26篇 |
灾害及防治 | 5篇 |
出版年
2023年 | 8篇 |
2022年 | 10篇 |
2021年 | 20篇 |
2020年 | 16篇 |
2019年 | 14篇 |
2018年 | 16篇 |
2017年 | 26篇 |
2016年 | 29篇 |
2015年 | 23篇 |
2014年 | 40篇 |
2013年 | 45篇 |
2012年 | 44篇 |
2011年 | 49篇 |
2010年 | 33篇 |
2009年 | 41篇 |
2008年 | 43篇 |
2007年 | 37篇 |
2006年 | 30篇 |
2005年 | 17篇 |
2004年 | 24篇 |
2003年 | 8篇 |
2002年 | 16篇 |
2001年 | 4篇 |
2000年 | 7篇 |
1999年 | 3篇 |
1998年 | 9篇 |
1997年 | 4篇 |
1996年 | 3篇 |
1995年 | 1篇 |
1994年 | 7篇 |
1993年 | 3篇 |
1992年 | 1篇 |
1991年 | 1篇 |
1990年 | 1篇 |
1987年 | 1篇 |
1985年 | 2篇 |
1981年 | 1篇 |
1978年 | 1篇 |
1974年 | 1篇 |
1971年 | 1篇 |
1970年 | 1篇 |
排序方式: 共有641条查询结果,搜索用时 31 毫秒
231.
Andrea Santangeli Marco Girardello Evan Buechley Andre Botha Enrico Di Minin Atte Moilanen 《Conservation biology》2019,33(5):1056-1065
The prosperity and well-being of human societies relies on healthy ecosystems and the services they provide. However, the biodiversity crisis is undermining ecosystems services and functions. Vultures are among the most imperiled taxonomic groups on Earth, yet they have a fundamental ecosystem function. These obligate scavengers rapidly consume large amounts of carrion and human waste, a service that may aid in both disease prevention and control of mammalian scavengers, including feral dogs, which in turn threaten humans. We combined information about the distribution of all 15 vulture species found in Europe, Asia, and Africa with their threats and used detailed expert knowledge on threat intensity to prioritize critical areas for conserving vultures in Africa and Eurasia. Threats we identified included poisoning, mortality due to collision with wind energy infrastructures, and other anthropogenic activities related to human land use and influence. Areas important for vulture conservation were concentrated in southern and eastern Africa, South Asia, and the Iberian Peninsula, and over 80% of these areas were unprotected. Some vulture species required larger areas for protection than others. Finally, countries that had the largest share of all identified important priority areas for vulture conservation were those with the largest expenditures related to rabies burden (e.g., India, China, and Myanmar). Vulture populations have declined markedly in most of these countries. Restoring healthy vulture populations through targeted actions in the priority areas we identified may help restore the ecosystem services vultures provide, including sanitation and potentially prevention of diseases, such as rabies, a heavy burden afflicting fragile societies. Our findings may guide stakeholders to prioritize actions where they are needed most in order to achieve international goals for biodiversity conservation and sustainable development. 相似文献
232.
Caitlin R. Gabor Rosalinda Gonzalez Michelle Parmley Andrea S. Aspbury 《Behavioral ecology and sociobiology》2010,64(5):783-792
Male sailfin mollies (Poecilia latipinna) are sexually parasitized by gynogenetic Amazon mollies (Poecilia formosa). In areas of sympatry, Amazon mollies are frequently larger than female sailfin mollies. In sympatry, selection may favor males that prefer smaller conspecific mates (avoid mismating with Amazon mollies), or selection may favor males that prefer larger conspecific mates (higher fecundity). To explore this potential species and mate-quality recognition conflict, we examined male preference variation across populations. Males from one sympatric population showed stabilizing preference functions, whereas in another sympatric population, males showed directional preference functions. Variation across sympatric populations may be related to the length of time of co-evolution with Amazon mollies. In the allopatric populations, we found flat preference functions. Variation in male preferences could have important ramifications for the maintenance of Amazon mollies, as well as for the evolution of female size. 相似文献
233.
Francesco Aristodemo Ivan Federico Paolo Veltri Andrea Panizzo 《Environmental Fluid Mechanics》2010,10(4):451-470
This paper deals with a two-dimensional numerical model based on the smoothed particle hydrodynamics (SPH) technique for the
evaluation of the concentration field of pollutants in water. A SPH model is formulated to solve the fickian diffusion equation
applied to pollutants with the same density as the water. A lagrangian SPH formalism of the advective diffusion equation is
also developed for pollutant-water, taking into account the effects of molecular diffusion and natural advection induced by
differences between the fluid densities. These equations are coupled with the fluid mechanics equations. Attention is paid
to the numerical aspects involved in the solution procedure and to the optimization of the model parameters. Environmental
engineering problems concerning diffusion and natural advection phenomena occur in the presence of a pollutant in still water.
Numerical tests referring to a strip and a bubble of contaminant in a water tank with different initial concentration laws
have been carried out. The results obtained by the proposed SPH models are compared with other available SPH formulations,
showing an overall better agreement with standard analytical solutions in terms of spatial evolution of the concentration
values. Capabilities and limits of the proposed SPH models to simulate advective diffusion phenomena for a wide range of density
ratios are discussed. 相似文献
234.
Several factors can affect occupational accident frequency, namely economical factors, technologies used (low automation, discontinuous operating) job design, organization of work/environmental conditions and human factors. In particular, technological advances in industrial activities can give rise to improvement in productivity and in occupational health and safety, but not necessarily simultaneously. The beginning of the container transport dates back to 50 years ago, but while containerization changed everything, from ships and ports to patterns of global trade, its impact on work injuries was not explored at all. The aim of this paper is to investigate the relationship between work organization, job experience, productivity and occupational accidents, from the starting of the container expansion to nowadays, considering Genoa port (Italy), one of the largest of the Mediterranean Sea. In order to minimize possible reporting biases, such as underreporting or reclassification to a lower level of severity, injury statistics are elaborated starting from data collected directly on-site, from internal accident or medical-aid reports. An in-depth statistical analysis on occupational injuries in the years 1980–2006 is carried out, with reference to frequency indexes, mechanism of injury and material causes. The increase of container-ships traffic and, consequently, the sharp change in port infrastructure involved a rapid modification also in the work organization, with particular reference to the number and characteristics of workforce (decrease from 5783 to nearly 1000 employees and increase of low experience workers from 28% to 74%). The striking high percentage increase of young or low experienced workers in handling container (and performing correlated new tasks) caused a remarkable increase of the risk for occupational injuries. In the studied port, we recorded an increase of the frequency index (injuries per hundred thousand hours worked) from 13.0 to 29.7. It results that the increased expansion of shipping container utilization is not connected to a correspondent human factor safety implementation. Main risk factors are pointed out, revealing an increase of accidents due to transport vehicle (+8.3%) and a reduction of accidents caused by substance or materials (?4.5%). These factors show a statistical significant correlation with the new job tasks. Consideration of these findings may enable managerial solutions and workplace organization interventions for the prevention of injuries and safety performance improvement in port activities. 相似文献
235.
236.
237.
238.
David M. Hetrick Andrea L. Sjoreen 《Journal of the American Water Resources Association》2004,40(5):1129-1140
ABSTRACT: Hydrologic Transport Assessment System (HYTRAS) is a software package that models contaminant transport in rivers and streams, including volatilization, adsorption/desorption, sedimentation, settling, and resuspension. Biodegradation, photolysis, and any other process that can be modeled using a first‐order decay constant can be included as well. HYTRAS originally modeled the transport of radionuclides and has recently been expanded to include transport of chemicals. The transport of chemicals has been validated using data from an accidental release of the chemicals disulfoton and thiometon into the Rhine River in 1986. For these chemicals, sorption is not an important process. For the range of measured flow velocities, HYTRAS was found to bound the peak arrival times. For the range of measured degradation rates, HYTRAS was found to bound the peak concentrations within 400 km of the source and bound the peak concentrations within a factor of two out to 700 km. 相似文献
239.
A New Respirometric Test Simulating Soil Burial Conditions for the Evaluation of Polymer Biodegradation 总被引:2,自引:0,他引:2
Roberto Solaro Andrea Corti Emo Chiellini 《Journal of Polymers and the Environment》1998,6(4):203-208
A new convenient and reliable method is described for assessing the biodegradation properties of polymeric materials under simulated soil burial conditions, which makes it possible to test with nutrient-rich soils. This method consists of the utilization of a minimum amount of a soil layer, in which the samples to be tested are set in close contact, sandwiched between two layers of perlite, a natural porous aluminosilicate. The biodegradation level is monitored by determining the carbon dioxide evolution derived from the test samples. The limited amount of soil used limits carbon dioxide evolution from the blanks, due to the corresponding limited overall amount of soil carbon. This experimental setup allows for an extremely satisfactory level of confidence in the analytical results, permitting a wider variety of soil types to be tested. 相似文献
240.
垃圾中转站是城市生活垃圾收运处置系统中一个必不可少的环节,合肥市居民生活垃圾中转站目前有31个,其中27个正常运行.由于合肥市垃圾采取卫生填埋处置,现有垃圾中转站的最大特点,就是将垃圾采用高强度的压缩技术进行"打包".我们对合肥市各区垃圾中转站分布及其具体情况也作了详细的调查,并对中转站的位置进行了卫星定位,以期为居民生活垃圾的清运机制的优化打下基础.在对合肥市老城区垃圾中转站进行调查的基础上,提出了合肥市老城区的中转站存在的问题,并对合肥市滨湖新区垃圾中转站的建设提出建议. 相似文献