全文获取类型
收费全文 | 651篇 |
免费 | 11篇 |
国内免费 | 4篇 |
专业分类
安全科学 | 29篇 |
废物处理 | 38篇 |
环保管理 | 143篇 |
综合类 | 78篇 |
基础理论 | 127篇 |
环境理论 | 1篇 |
污染及防治 | 186篇 |
评价与监测 | 28篇 |
社会与环境 | 32篇 |
灾害及防治 | 4篇 |
出版年
2023年 | 4篇 |
2022年 | 4篇 |
2021年 | 6篇 |
2020年 | 3篇 |
2019年 | 6篇 |
2018年 | 10篇 |
2017年 | 13篇 |
2016年 | 12篇 |
2015年 | 13篇 |
2014年 | 12篇 |
2013年 | 70篇 |
2012年 | 24篇 |
2011年 | 41篇 |
2010年 | 29篇 |
2009年 | 29篇 |
2008年 | 29篇 |
2007年 | 37篇 |
2006年 | 36篇 |
2005年 | 25篇 |
2004年 | 31篇 |
2003年 | 23篇 |
2002年 | 19篇 |
2001年 | 12篇 |
2000年 | 10篇 |
1999年 | 5篇 |
1998年 | 7篇 |
1997年 | 7篇 |
1996年 | 8篇 |
1995年 | 13篇 |
1994年 | 8篇 |
1993年 | 5篇 |
1992年 | 8篇 |
1991年 | 10篇 |
1990年 | 7篇 |
1988年 | 5篇 |
1987年 | 5篇 |
1986年 | 9篇 |
1985年 | 5篇 |
1984年 | 12篇 |
1983年 | 8篇 |
1982年 | 11篇 |
1981年 | 3篇 |
1979年 | 9篇 |
1977年 | 2篇 |
1975年 | 2篇 |
1972年 | 2篇 |
1969年 | 2篇 |
1967年 | 3篇 |
1939年 | 1篇 |
1935年 | 1篇 |
排序方式: 共有666条查询结果,搜索用时 171 毫秒
61.
Pryor SC Larsen SE Sørensen LL Barthelmie RJ 《Environmental pollution (Barking, Essex : 1987)》2008,152(3):667-678
This paper reports a study designed to test, evaluate and compare micro-meteorological methods for determining the particle number flux above forest canopies. Half-hour average particle number fluxes above a representative broad-leaved forest in Denmark derived using eddy covariance range from -7x10(7) m(-2) s(-1) (1st percentile) to 5x10(7) m(-2) s(-1) (99th percentile), and have a median value of -1.6x10(6) m(-2) s(-1). The statistical uncertainties associated with the particle number flux estimates are larger than those for momentum fluxes and imply that in this data set approximately half of the particle number fluxes are not statistically different to zero. Particle number fluxes from relaxed eddy accumulation (REA) and eddy covariance are highly correlated and of almost identical magnitude. Flux estimates from the co-spectral and dissipation methods are also correlated with those from eddy covariance but exhibit higher absolute magnitude of fluxes. 相似文献
62.
This paper investigates the impact of the recent criminalisation of humanitarian actors engaged in the search for and rescue of migrants in distress in the Mediterranean Sea, focusing on the impact on the motivation and engagement of humanitarian volunteers in Greece. It argues that criminalisation is aimed at reducing search and rescue (SAR) activities and thus removing perceived ‘pull factors’ for migrants. The paper locates this phenomenon within the broader trend of policing and punishing those who assist migrants in order to deter them and prevent others from engaging in such endeavours. It finds that efforts to criminalise can have the unintended effects of encouraging and mobilising volunteers, as well as generating public attention and support for migrants. However, the negative consequences of criminalisation are far-reaching, including contributing to a high mortality rate among those crossing the Mediterranean without SAR capabilities and the heightened risk of violence against migrants and those who help them. 相似文献
63.
This study was conducted in the Swedish sub-Arctic, near Abisko, in order to assess the direction and scale of possible vegetation
changes in the alpine–birch forest ecotone. We have re-surveyed shrub, tree and vegetation data at 549 plots grouped into
61 clusters. The plots were originally surveyed in 1997 and re-surveyed in 2010. Our study is unique for the area as we have
quantitatively estimated a 19% increase in tree biomass mainly within the existing birch forest. We also found significant
increases in the cover of two vegetation types—“birch forest-heath with mosses” and “meadow with low herbs”, while the cover
of snowbed vegetation decreased significantly. The vegetation changes might be caused by climate, herbivory and past human
impact but irrespective of the causes, the observed transition of the vegetation will have substantial effects on the mountain
ecosystems. 相似文献
64.
Rundqvist S Hedenås H Sandström A Emanuelsson U Eriksson H Jonasson C Callaghan TV 《Ambio》2011,40(6):683-692
Shrubs and trees are expected to expand in the sub-Arctic due to global warming. Our study was conducted in Abisko, sub-arctic
Sweden. We recorded the change in coverage of shrub and tree species over a 32– to 34-year period, in three 50 × 50 m plots;
in the alpine-tree-line ecotone. The cover of shrubs and trees (<3.5 cm diameter at breast height) were estimated during 2009–2010
and compared with historical documentation from 1976 to 1977. Similarly, all tree stems (≥3.5 cm) were noted and positions
determined. There has been a substantial increase of cover of shrubs and trees, particularly dwarf birch (Betula nana), and mountain birch (Betula pubescens ssp. czerepanovii), and an establishment of aspen (Populus tremula). The other species willows (Salix spp.), juniper (Juniperus communis), and rowan (Sorbus aucuparia) revealed inconsistent changes among the plots. Although this study was unable to identify the causes for the change in shrubs
and small trees, they are consistent with anticipated changes due to climate change and reduced herbivory. 相似文献
65.
Stakeholders on Meat Production, Meat Consumption and Mitigation of Climate Change: Sweden as a Case
Henrik Lerner Bo Algers Stefan Gunnarsson Anders Nordgren 《Journal of Agricultural and Environmental Ethics》2013,26(3):663-678
In this paper we analyse and discuss the views of Swedish stakeholders on how to mitigate climate change to the extent it is caused by meat production. The stakeholders include meat producer organisations, governmental agencies with direct influence on meat production, political parties as well as non-governmental organisations. Representatives of twelve organisations were interviewed. Several organisations argued against the mitigation option of reducing beef production despite the higher greenhouse gas intensity of beef compared to pork and chicken meat (according to life cycle analysis). Regarding feed production some organisations proposed use of the best available industrial fertilizers, others were against all use of such fertilizers. Several organizations suggested domestic production of more protein-rich fodder and use of manure for biogas production. Regarding meat consumption the focus was on throwing away less food as waste and on eating less meat but the best (most climate friendly) meat, which was considered to be Swedish meat in contrast to imported meat. There was agreement on many issues. Most disagreement was found regarding political steering. We find many of the stakeholders’ mitigation proposals regarding meat production and consumption acceptable. However, we are to some extent critical to their defence of Swedish beef production. We also point out certain problems with the suggestion to reduce consumption of imported meat but not of domestically produced meat. 相似文献
66.
Fred M. Vukovich 《Journal of the Air & Waste Management Association (1995)》2013,63(12):2067-2072
ABSTRACT This study examined the spatial distribution of the weekday/weekend difference in Baltimore, MD, and vicinity. The difference in Baltimore was characterized by having ~39% more NOx , ~59% more CO, and ~27% more volatile organic compounds (VOCs) on the average weekday, but there was ~13% more O3 on the weekend day. Spatially, the difference was elongated in the northeast-southwest direction. It decreased from 13% more O3 in Baltimore to 6% at ~20 km west of Baltimore and to 4% at ~40 km south of Baltimore. It also appeared to decrease to the east, but the magnitude of the decrease could not be determined because of the lack of data east of the Chesapeake Bay. However, the difference increased to the north, reaching a value of almost 18% at a northern Delaware site. 相似文献
67.
68.
69.
Eric S. Larsen Michael J. Pilat 《Journal of the Air & Waste Management Association (1995)》2013,63(9):1199-1206
An activated carbon moving bed system (10 to 100 acf m air flow) was tested for controlling VOC emissions from a commercial aircraft painting facility. The cross-flow moving adsorbent bed showed a VOC collection efficiency in the 77.1 to 99.6 percent range over a superficial gas velocity range of 27 to 185 ft/min (0.14-0.94 m/sec). The collection efficiencies were neither affected by a change in carbon flow rates from 5 to 8 Ib/hr (2.3 to 3.6 kg/hr) nor by a change in the gas superficial velocity from 27 to 185 ft/min. The VOC concentration in the emission stream from the painting hangar was found to vary by at least a factor of 20 (from 0.18 to 15 ppm) both over the five month period (during which the 15 system tests of about three hours each were conducted) and within a single eight hour work shift. 相似文献
70.
James S. Dusenbury Fred S. Cannon 《Journal of the Air & Waste Management Association (1995)》2013,63(7):871-889
Abstract The objective of this research was to investigate a sequentially loaded and regenerated granular activated carbon (GAC) biofilter system and to determine whether regenerative ozonation/advanced oxidation could improve the removal and biodegradation of a volatile organic compound from a contaminated airstream. Bench-scale reactors were constructed to operate in a manner analogous to a commercially available system manufactured by Terr-Aqua Environmental Systems (only with longer contact time). The GAC system consisted of two GAC biofilter beds that operated in a cyclical manner. On a given day, the first GAC bed adsorbed methyl isobutyl ketone from a simulated waste airstream, while the second bed underwent regeneration; then on the next day, the second bed was in the adsorption mode while the first was regenerated. Three bench-scale systems were used to compare the performance under three operating conditions: (1) ozone/ associated oxidant regeneration of a GAC biofilter system that was seeded with microorganisms from a field site, (2) a humid air regeneration of a seeded GAC biofilter, and (3) a humid air regeneration of an unseeded GAC biofilter. For the advanced oxidant regenerated GAC biofilter, a maximum removal efficiency of >95% was achieved with an empty bed contact time of 148 sec and an influent concentration of 125 ppm methyl isobutyl ketone, and 90–95% was achieved at 148-sec empty bed contact time and a 1150-ppm influent. 相似文献