全文获取类型
收费全文 | 3588篇 |
免费 | 61篇 |
国内免费 | 34篇 |
专业分类
安全科学 | 206篇 |
废物处理 | 117篇 |
环保管理 | 947篇 |
综合类 | 345篇 |
基础理论 | 879篇 |
环境理论 | 7篇 |
污染及防治 | 790篇 |
评价与监测 | 227篇 |
社会与环境 | 132篇 |
灾害及防治 | 33篇 |
出版年
2023年 | 15篇 |
2022年 | 23篇 |
2021年 | 27篇 |
2020年 | 27篇 |
2019年 | 35篇 |
2018年 | 43篇 |
2017年 | 68篇 |
2016年 | 83篇 |
2015年 | 74篇 |
2014年 | 75篇 |
2013年 | 451篇 |
2012年 | 132篇 |
2011年 | 178篇 |
2010年 | 119篇 |
2009年 | 135篇 |
2008年 | 156篇 |
2007年 | 198篇 |
2006年 | 136篇 |
2005年 | 119篇 |
2004年 | 125篇 |
2003年 | 127篇 |
2002年 | 108篇 |
2001年 | 63篇 |
2000年 | 79篇 |
1999年 | 49篇 |
1998年 | 56篇 |
1997年 | 47篇 |
1996年 | 62篇 |
1995年 | 60篇 |
1994年 | 64篇 |
1993年 | 54篇 |
1992年 | 48篇 |
1991年 | 43篇 |
1990年 | 38篇 |
1989年 | 31篇 |
1988年 | 43篇 |
1987年 | 31篇 |
1986年 | 35篇 |
1985年 | 34篇 |
1984年 | 32篇 |
1983年 | 37篇 |
1982年 | 48篇 |
1981年 | 47篇 |
1980年 | 25篇 |
1979年 | 28篇 |
1978年 | 26篇 |
1977年 | 29篇 |
1976年 | 14篇 |
1974年 | 10篇 |
1972年 | 11篇 |
排序方式: 共有3683条查询结果,搜索用时 296 毫秒
701.
Robert J. Pheasant Mark N. Fisher Greg R. Watts David J. Whitaker Kirill V. Horoshenkov 《Journal of environmental psychology》2010,30(4):501-509
In a world of sensory overload, it is becoming increasingly important to provide environments that enable us to recover our sense of well being. Such restorative (‘tranquil’) environments need to comprise sufficient sensory stimulation to keep us engaged, whilst at the same time providing opportunity for reflection and relaxation. One essential aspect in safeguarding existing, or developing new ‘tranquil space’, is understanding the optimum relationship between the soundscape and the visual composition of a location. This research represents a first step in understanding the effects of audio-visual interaction on the perception of tranquillity and identifies how the interpretation of acoustic information is an integral part of this process. By using uni and bi-modal auditory-visual stimuli in a two stage experimental strategy, it has been possible to measure the key components of the tranquillity construct. The findings of this work should be of particular interest to those charged with landscape management, such as National Park Authorities, Regional Councils, and other agencies concerned with providing and maintaining public amenity. 相似文献
702.
703.
704.
Moriarity Robert J. Tsuji Leonard J. S. Liberda Eric N. 《Environmental science and pollution research international》2023,30(6):14304-14317
Environmental Science and Pollution Research - Hunting, trapping, and fishing are part of an Indigenous lifestyle in subarctic Canada. However, this lifestyle may be a route of exposure to... 相似文献
705.
Permanent vegetation plots were established on mixed overburden and topsoiled overburden on a lignite test pit in eastern Texas in 1982. Vegetative treatments included two grass-legume treatments [switchgrass (panicum virgattun) — sideoats grama (Bouteloua curtipendula) — subterrancan elover (Trifolitun subterranean) and litte bluestem (Schizachyriun scoparium) — sideoats grama (Bouteloua curtipendula) — Illinois hundleflower (Dessmanthus illinoiensis)] and three monocultures [Coastal bermudagrass (Cynodon dactylon), bahia grass (paspalum notatum) and yellow Indiangrass (Sorghastrum nutans)]. Water was applied to the 0.5m2 plots using a sprinklertype rainfall simulator and quality of runoff was determined for each plot. Parameters analyzed included: settleable solids, total filterable solids, sediment production, infiltration rate, nitrites, nitrates, total iron and total manganese. Topsoiling significantly increased inliltration and significantly decreased filterable sediments, sediment production and settleable solids. The hydrologie qualities of the switchgrass-sideoats grama-subterranean elover mixture coincided closely with those of the Coastal bermudagrass monoculture.Authors are presently graduate research assistant and assistant professor. Range Science Department. Texas A&M University. College Station, Texas 77843. Acknowledgement is given to Northwestern Resources Co. for providing the funding for this project. 相似文献
706.
This study was implemented to determine the effects of one, two, or three months of establishment irrigation, after spring or summer seeding on the long-term composition of mined land plant associations. While the treatment plots were seeded with the same diverse mixture of native species, floristic differences among treatment combinations were apparent after five growing seasons. Summer seeding enhanced the development of seeded warm-season grasses by retarding the initial development of seeded cool-season grasses and by limiting competitive effects of nonseeded species through seedbed tillage. Supplemental irrigation was substantially more important to the development of warm- than cool-season grasses. Seeded perennial forbs performed poorly on all treatments, presumably due to low seed viability, low germination, and/or competition from more water-responsive species. Despite drought conditions during plant establishment, supplemental irrigation was not critical to the ultimate development of nonseeded plant species when seedbed tillage occurred shortly after topsoil was applied. However, irrigation became more important to the long-term development of these species when tillage was delayed. Most forbs encountered were perennial natives that had volunteered from the direct-haul topsoil.Atriplex canescens was the only successful seeded shrub and performed particularly well on the summer seeded plot that received one month of initial irrigation.Authors are research plant ccologist and director of research. This contribution submitted as Montana Agricultural Experiment Station Journal Series No. J-1560. This study was funded entirely by the Western Energy Company, Butte, Montana. The authors express their appreciation to Bill Schwarzkoph and Joe Cocnenberg of Western Energy Company, and former Reclamation Research Unit members Ed DePuit, Chet Skilbred, and Steve Young for their participation in the early stages of this study. 相似文献
707.
708.
709.
Feeding behavior in sexual and clonal strains of Poeciliopsis 总被引:1,自引:0,他引:1
Stephen C. Weeks Oscar E. Gaggiotti Russell A. Schenck Kurt P. Spindler Robert C. Vrijenhoek 《Behavioral ecology and sociobiology》1992,30(1):1-6
Summary Sexual and clonal fish of the genus Poeciliopsis occur together in desert streams of Sonora, Mexico. Their coexistence has been explained in terms of niche partitioning for food and space. We examined predatory behavior that might influence niche relationships, and found significant differences among two coexisting sperm-dependent clonal strains and their two sexual progenitors. Handling time and prey manipulation of free-swimming (Artemia) and benthic (chironomid larvae) prey differed significantly among sexual and clonal strains. Analyses of gut contents from field-collected fish revealed that the laboratory estimates of predatory efficiency were related to their feeding behavior in nature. Behavior differences, such as those described herein, contribute to our understanding of the mechanisms of unisexual/bisexual coexistence in Poeciliopsis.
Offprint requests to: R.C. Vrijenhoek 相似文献
710.