全文获取类型
收费全文 | 578篇 |
免费 | 12篇 |
国内免费 | 7篇 |
专业分类
安全科学 | 14篇 |
废物处理 | 38篇 |
环保管理 | 42篇 |
综合类 | 65篇 |
基础理论 | 155篇 |
污染及防治 | 184篇 |
评价与监测 | 54篇 |
社会与环境 | 43篇 |
灾害及防治 | 2篇 |
出版年
2023年 | 7篇 |
2022年 | 20篇 |
2021年 | 14篇 |
2020年 | 8篇 |
2019年 | 12篇 |
2018年 | 26篇 |
2017年 | 26篇 |
2016年 | 34篇 |
2015年 | 14篇 |
2014年 | 32篇 |
2013年 | 49篇 |
2012年 | 42篇 |
2011年 | 55篇 |
2010年 | 34篇 |
2009年 | 38篇 |
2008年 | 29篇 |
2007年 | 34篇 |
2006年 | 24篇 |
2005年 | 26篇 |
2004年 | 16篇 |
2003年 | 15篇 |
2002年 | 4篇 |
2001年 | 8篇 |
2000年 | 9篇 |
1999年 | 2篇 |
1997年 | 3篇 |
1996年 | 3篇 |
1993年 | 3篇 |
1992年 | 1篇 |
1991年 | 3篇 |
1990年 | 2篇 |
1989年 | 1篇 |
1988年 | 1篇 |
1986年 | 1篇 |
1972年 | 1篇 |
排序方式: 共有597条查询结果,搜索用时 0 毫秒
81.
This paper examines the effects of asymmetric voter information on the environmental policies of democratic governments. The model builds on the electoral signaling model of Rogoff to illustrate the possibility that democratic governments may systematically overlegislate-and yet underenforce-environmental standards in a rational expectations equilibrium. The model also offers insights into the welfare implications of "right to know" legislation, proposals to depoliticize environmental policy, and private voluntary institutions. 相似文献
82.
Cesaro Alessandra Marra Alessandra Belgiorno Vincenzo Siciliano Antonietta Guida Marco 《Journal of Material Cycles and Waste Management》2018,20(2):1188-1198
Journal of Material Cycles and Waste Management - Cathode ray tube (CRT) monitors represent currently one of the most produced category of electronic waste. In CRTs most of the glass components... 相似文献
83.
Effective selective collection (SC) has been increasing in many countries of the European Union. As a consequence the composition of residual municipal solid waste (RMSW) is changing not only because of economic development, but also due to the collection system. The input of RMSW treatment plants is thus not homogeneous. This paper analyses two case studies involving a total of five SC scenarios and their impact on the generation of solid recovered fuel (SRF) with/without bio-drying, post-treatment and packaging take back programs (TBPs). These case studies are based on two types of SC: kerbside and drop-off. The latest regulation on SRF classification is taken into account: energy content, Cl and Hg concentrations are assessed and discussed. The role of the respirometric index (RI) is also analyzed. Results show that when SC is highly efficient RMSW can be classified directly as SRF, but only if the introduction of RI does not set stringent respirometric targets. The role of packaging TBPs is important as the residual waste remaining after the packaging has been processed, can be valorized increasing the lower heating value (LHV) of the residual RMSW and minimizing the streams that should be landfilled. The source separation of food waste has a significant impact on the suitability of bio-drying: when the SC of food waste is very efficient, its percentage in the RMSW may be too low for effective bio-drying. 相似文献
84.
Patrick Bergeron Stefano Grignolio Marco Apollonio Bill Shipley Marco Festa-Bianchet 《Behavioral ecology and sociobiology》2010,64(8):1299-1307
Social dominance is a fundamental aspect of male evolutionary ecology in polygynous mammals because it determines access to
estrous females. As it is rarely possible to monitor marked individuals of known morphology, little is known about the determinants
of male dominance. We studied the social structure of Alpine ibex males in Gran Paradiso National Park, Italy in 2003, 2006,
and 2007. Dominance interactions produced a linear social hierarchy. In ibex males, body mass and horn length are key traits
in male-male combat, and both increase with age. We explored the links between age, body mass, horn length, and social rank.
Ibex males showed much age-independent phenotypic heterogeneity and rapidly growing males reached high rank at a younger age
than slow-growing males. Because there is no trade-off between horn growth and longevity, fast-growing males may face weak
potential costs of rapid growth and high fitness benefit of achieving high rank. Violent interactions were more likely to
occur between males similar in both mass and horn length, independently of age. We suggest that only high-quality individuals
can afford a strategy of rapid growth for both secondary sexual characters, and likely reap substantial fitness benefits. 相似文献
85.
Marco Ghisalberti 《Environmental Fluid Mechanics》2010,10(3):329-343
Obstructed shear flows (i.e. those over permeable media) are common in the environment. An archetypal example, flow over a
submerged vegetation canopy, is investigated here. Like any flow through complex geometry, canopy flows are characterised
by strong spatial gradients. The focus of this experimental study is the three-dimensionality of aquatic canopy flow, in particular
that of the coherent interfacial vortices that govern mixing into and out of the canopy. It is shown here that the vortices
have a finite lateral scale that is comparable to their vertical scale; both are of the order of the drag length scale of
the canopy, (C
D
a)−1, where a is the frontal area density and C
D
is a bulk drag coefficient. The finite lateral extent of the vortices generates strong lateral hydrodynamic gradients, both
instantaneously and in the long-term. The instantaneous gradients, which can contribute greatly to the dispersion of dissolved
and particulate species, are far more pronounced. Finally, the potential for canopies to generate differential roughness secondary
circulation is examined. In the consideration of vertical scalar transport, this circulation can be of the same order as turbulent
diffusion. 相似文献
86.
Spatial distribution and temporal variation of epibenthic assemblages of coralligenous biogenic rocky outcrops occurring in
the northern Adriatic Sea (45°04′–45°24′N; 12°23′–12°43′E) were investigated by photographic sampling from 2003 to 2006 at
12 randomly selected sites. The dominant reef-forming organisms were the encrusting calcareous algae (Lithophyllum stictaeforme, Lithothamnion minervae and Peyssonnelia polymorpha), while the main bioeroders were boring sponges (Cliona viridis, C. celata, C. thoosina, C. rhodensis, Piona vastifica) and the bivalve Gastrochaena dubia. Composition of the assemblages varied thorough years and among sites. Spatial heterogeneity, at local and regional scale,
prevailed over temporal variation. This variability was related both to the geo-morphological features of the outcrops and
to environmental variables. Sites clearly differed in the percent cover of reef builder and bioeroder species while only limited
temporal variation within site was found. Some taxa revealed complex intra-site temporal trends. These results provide valuable
information on the diversity and variability of epibenthic assemblages of the northern Adriatic coralligenous reefs, essential
for the management and conservation of these unique biogenic habitats. 相似文献
87.
Marco Martínez-Cinco Jesús Santos-Guzmán 《Journal of the Air & Waste Management Association (1995)》2016,66(6):631-642
The Monterrey Metropolitan Area (MMA) in Northeast Mexico has shown high PM2.5 concentrations since 2003. The data shows that the annual average concentration exceeds from 2 to 3 times the Mexican PM2.5 annual air quality standard of 12 µg/m3. In a previous work we studied the chemical characterization of PM2.5 in two sites of the MMA during the winter season. Among the most important components we found ammonium sulfate and nitrate, elemental and organic carbon, and crustal matter. In this work we present the results of a second chemical characterization study performed during the summer time and the application of the chemical mass balance (CMB) model to determine the source apportionment of air pollutants in the region. The chemical analysis results show that the chemical composition of PM2.5 is similar in both sites and periods of the year. The results of the chemical analysis and the CMB model show that industrial, traffic, and combustion activities in the area are the major sources of primary PM2.5 and precursor gases of secondary inorganic and organic aerosol (SO2, NOx, NH3, and volatile organic compounds [VOCs]). We also found that black carbon and organic carbon are important components of PM2.5 in the MMA. These results are consistent with the MMA emission inventory that reports as major sources of particles and SO2 a refinery and fuel combustion, as well as nitrogen oxides and ammonium from transportation and industrial activities in the MMA and ammonium form agricultural activities in the state. The results of this work are important to identify and support effective actions to reduce direct emissions of PM2.5 and its precursor gases to improve air quality in the MMA. Implications: The Monterrey Metropolitan Area (MMA) has been classified as the most air-polluted area in Mexico by the World Health Organization (WHO). Effective actions need to be taken to control primary sources of PM2.5 and its precursors, reducing health risks on the population exposed and their associated costs. The results of this study identify the main sources and their estimated contribution to PM2.5 mass concentration, providing valuable information to the local environmental authorities to take decisions on PM2.5 control strategies in the MMA. 相似文献
88.
Honeybee colonies (Apis mellifera) maintain temperatures of 35-36°C in their brood nest because the brood needs high and constant temperature conditions for optimal development. We show that incubation of the brood at the level of individual honeybees is done by worker bees performing a particular and not yet specified behaviour: such bees raise the brood temperature by pressing their warm thoraces firmly onto caps under which the pupae develop. The bees stay motionless in a characteristic posture and have significantly higher thoracic temperatures than bees not assuming this posture in the brood area. The surface of the brood caps against which warm bees had pressed their thorax were up to 3.2°C warmer than the surrounding area, confirming that effective thermal transfer had taken place. 相似文献
89.
90.