全文获取类型
收费全文 | 217篇 |
免费 | 1篇 |
国内免费 | 1篇 |
专业分类
安全科学 | 3篇 |
废物处理 | 6篇 |
环保管理 | 14篇 |
综合类 | 142篇 |
基础理论 | 35篇 |
污染及防治 | 14篇 |
评价与监测 | 1篇 |
社会与环境 | 4篇 |
出版年
2023年 | 3篇 |
2015年 | 2篇 |
2014年 | 3篇 |
2013年 | 10篇 |
2012年 | 5篇 |
2011年 | 6篇 |
2009年 | 3篇 |
2008年 | 3篇 |
2007年 | 3篇 |
2006年 | 7篇 |
2005年 | 5篇 |
2004年 | 2篇 |
2003年 | 7篇 |
2002年 | 3篇 |
2001年 | 2篇 |
2000年 | 3篇 |
1999年 | 2篇 |
1998年 | 4篇 |
1992年 | 2篇 |
1991年 | 2篇 |
1978年 | 2篇 |
1967年 | 3篇 |
1966年 | 2篇 |
1965年 | 5篇 |
1964年 | 3篇 |
1963年 | 5篇 |
1962年 | 4篇 |
1959年 | 6篇 |
1957年 | 2篇 |
1956年 | 4篇 |
1955年 | 6篇 |
1954年 | 5篇 |
1951年 | 6篇 |
1950年 | 5篇 |
1949年 | 2篇 |
1947年 | 2篇 |
1946年 | 3篇 |
1941年 | 5篇 |
1940年 | 6篇 |
1939年 | 5篇 |
1938年 | 2篇 |
1937年 | 7篇 |
1934年 | 2篇 |
1932年 | 4篇 |
1930年 | 2篇 |
1929年 | 2篇 |
1923年 | 2篇 |
1920年 | 4篇 |
1918年 | 2篇 |
1913年 | 2篇 |
排序方式: 共有219条查询结果,搜索用时 312 毫秒
1.
Carly E. Federman Durelle T. Scott Erich T. Hester 《Journal of the American Water Resources Association》2023,59(1):29-48
River flooding impacts human life and infrastructure, yet provides habitat and ecosystem services. Traditional flood control (e.g., levees, dams) reduces habitat and ecosystem services, and exacerbates flooding elsewhere. Floodplain restoration (i.e., bankfull floodplain reconnection and Stage 0) can also provide flood management, but has not been sufficiently evaluated for small frequent storms. We used 1D unsteady Hydrologic Engineering Center's River Analysis System to simulate small storms in a 5 km-long, second-order generic stream from the Chesapeake Bay watershed, and varied % channel restored (starting at the upstream end), restoration location, restoration bank height (distinguishes bankfull from Stage 0 restoration), and floodplain width/Manning's n. Stream restoration decreased (attenuated) peak flow up to 37% and increased floodplain exchange by up to 46%. Floodplain width and % channel restored had the largest impact on flood attenuation. The incremental effects of new restoration projects on flood attenuation were greatest when little prior restoration had occurred. By contrast, incremental effects on floodplain exchange were greatest in the presence of substantial prior restoration, setting up a tradeoff. A similar tradeoff was revealed between attenuation and exchange for project location, but not bank height or floodplain width. In particular, attenuation and exchange were always greater for Stage 0 than for bankfull floodplain restoration. Stage 0 thus may counteract human impacts such as urbanization. 相似文献
2.
3.
Erich Huster 《Die Naturwissenschaften》1977,64(9):448-460
This paper deals with the history of exoelectron emission (EE), as well as with the experimental results and the attempts to explain them. The author concludes that thermally and optically stimulated EE (TSEE, OSEE) are different phenomena and that OSEE is mere photoeffect. The source of the energy causing the emission has been heatedly discussed. The author believes that most of the models can be ruled out by the fact that the activation energies do not depend on the nature of the metal nor on its oxide. He supposes the simplest model—direct thermal emission from surface traps—to be right. The author concludes that none of the excitation processes produces electron traps, as is often assumed. They only fill existing traps with electrons, e.g., radiation, mechanical treatment or a simple dip in water. 相似文献
4.
5.
6.
7.
Egarter Vigl Lukas Tasser Erich Schirpke Uta Tappeiner Ulrike 《Regional Environmental Change》2017,17(8):2237-2250
Regional Environmental Change - Managing multiple ecosystem services (ES) in agricultural landscapes is a challenging task, especially in regions with complex topographical and agro-ecological... 相似文献
8.
Brenda Maria Zoderer Paola Sabina Lupo Stanghellini Erich Tasser Janette Walde Harald Wieser Ulrike Tappeiner 《Regional Environmental Change》2016,16(7):2033-2044
The socio-cultural assessment of ecosystem services has been proposed as a promising tool for eliciting people’s preferences towards ecosystem services. Despite an increasing integration of the socio-cultural perspective in ecosystem service research, little knowledge exists about linkages between landscape and the socio-cultural values people assign to ecosystem services. This paper combines a socio-cultural valuation approach with the use of landscape pictures to analyse and compare people’s perceived importance of the provisioning, regulating, and cultural ecosystem service categories across three landscape types (i.e. larch meadows, spruce forests, and hay meadow). A survey with 470 tourists visiting the region of South Tyrol (Italy) was conducted to link people’s perceived importance to their socio-demographic background and to the landscape types explored. The results show that regulating ecosystem services are preferred over provisioning and cultural services, whereby environmental awareness is found to be more influential than formal education levels regarding the perceived importance of regulating services. The results further demonstrate that cultural background is an important driver in determining people’s perceived importance of cultural services. The underlying landscape types, however, exert an even stronger influence on people’s socio-cultural valuation of ecosystem service categories. This finding suggests that the focus of most ecosystem services assessments on the study area as a whole risks mistakenly attributing differences in people’s socio-cultural values to socio-demographic characteristics only. A better knowledge of the spatial integration of socio-cultural values, however, could help with anticipating the consequences of changes in the landscape and provide better guidance for future landscape planning. 相似文献
9.
A growing literature has suggested that high performance goals can have unintended consequences within organizations as employees engage in unethical behavior to achieve outcomes associated with goal attainment. Extending research on the dark side of goal setting, we suggest that high performance goals not only create a desire to achieve a particular outcome but also alter moral reasoning processes related to goal attainment. Integrating goal-setting theory with motivated moral reasoning, we hypothesize an indirect effect of high performance goals on unethical behavior via state moral disengagement. We also examine goal commitment—which tends to amplify the relationship between high goals and performance—as a key boundary condition associated with this indirect effect. We build this conditional indirect effect model across three studies conducted in the field and the laboratory. Our results provide new insight into both when and why high goals can facilitate moral disengagement and unethical behavior within organizations. 相似文献
10.
Erich Weber 《Journal of the Air & Waste Management Association (1995)》2013,63(6):657-659
The NATO Council has in November, 1979, on the occasion of its autumn session, consented to the final report of the Pilot Study “Air Pollution Assessment Methodology and Modeling” which had been proposed by the Federal Republic of Germany and approved by NATO/CCMS in May, 1976. The recommendations on measures for air pollution control in the NATO member countries contained in the Final Report were adopted unanimously. 相似文献