全文获取类型
收费全文 | 321篇 |
免费 | 0篇 |
国内免费 | 8篇 |
专业分类
安全科学 | 6篇 |
废物处理 | 19篇 |
环保管理 | 33篇 |
综合类 | 146篇 |
基础理论 | 54篇 |
环境理论 | 2篇 |
污染及防治 | 54篇 |
评价与监测 | 9篇 |
社会与环境 | 6篇 |
出版年
2020年 | 3篇 |
2019年 | 3篇 |
2018年 | 4篇 |
2017年 | 8篇 |
2016年 | 6篇 |
2015年 | 5篇 |
2013年 | 17篇 |
2012年 | 7篇 |
2011年 | 13篇 |
2010年 | 7篇 |
2009年 | 13篇 |
2008年 | 11篇 |
2007年 | 8篇 |
2006年 | 6篇 |
2005年 | 7篇 |
2004年 | 3篇 |
2003年 | 6篇 |
2002年 | 14篇 |
1999年 | 9篇 |
1998年 | 6篇 |
1996年 | 8篇 |
1994年 | 6篇 |
1993年 | 4篇 |
1992年 | 3篇 |
1991年 | 7篇 |
1990年 | 9篇 |
1989年 | 6篇 |
1987年 | 3篇 |
1982年 | 3篇 |
1981年 | 5篇 |
1980年 | 3篇 |
1979年 | 3篇 |
1975年 | 3篇 |
1974年 | 3篇 |
1973年 | 8篇 |
1969年 | 3篇 |
1968年 | 2篇 |
1966年 | 2篇 |
1965年 | 5篇 |
1964年 | 3篇 |
1963年 | 5篇 |
1962年 | 3篇 |
1961年 | 6篇 |
1960年 | 4篇 |
1959年 | 3篇 |
1958年 | 5篇 |
1957年 | 6篇 |
1955年 | 2篇 |
1954年 | 5篇 |
1927年 | 2篇 |
排序方式: 共有329条查询结果,搜索用时 218 毫秒
321.
322.
Objective
To evaluate CarFit, an educational program designed to promote optimal alignment of driver with vehicle.Methods
A driving activity survey was sent to 727 randomly selected participants living in retirement communities. Drivers (n = 195) were assigned randomly to CarFit intervention (n = 83, M age = 78.1) or Comparison (n = 112, M age = 79.6) groups. After 6 months, participants completed a post-test of driving activity and CarFit recommendations.Results
Nonconsenting drivers were older and participated in fewer driving activities. CarFit participation was moderate (71%) with 86% of the participants receiving recommendations. 60% followed the recommendations at the 6-month re-evaluation). The CarFit (67.6%) and Comparison (59.3%) groups reported at least one type of self-regulation of driving activity at baseline. There was no significant change in the driving behaviors at the six-month follow-up.Conclusion
CarFit was able to detect addressable opportunities that may contribute to the safety of older drivers.Impact on industry
CarFit recommendations may need stronger reinforcement in order to be enacted by a participant. 相似文献323.
For anisotropic density functions of e.g. fruit or leaf dispersal, most mathematical research is only done in polar coordinates. However, in software solutions aiming to derive inverse models for real world dispersal data, Cartesian coordinates may be preferred for several reasons. Thus, we introduce an anisotropic model in Cartesian coordinates following the approach in Wälder et al. (2009) with the von Mises approach. By introducing a correction factor, we thereby consider the fundamental attribute, that the integral over a density function with respect to the Cartesian coordinates has to be equal 1. It may have been overlooked so far that guaranteeing for this attribute needs different approaches whether working in polar or Cartesian coordinates. One result is that our approach can be used also for other anisotropic models rather than models from the von Mises approach. 相似文献
324.
Cardoso NF Lima EC Pinto IS Amavisca CV Royer B Pinto RB Alencar WS Pereira SF 《Journal of environmental management》2011,92(4):1237-1247
The cupuassu shell (Theobroma grandiflorum) which is a food residue was used in its natural form as biosorbent for the removal of C.I. Reactive Red 194 and C.I. Direct Blue 53 dyes from aqueous solutions. This biosorbent was characterized by infrared spectroscopy, scanning electron microscopy, and nitrogen adsorption/desorption curves. The effects of pH, biosorbent dosage and shaking time on biosorption capacities were studied. In acidic pH region (pH 2.0) the biosorption of the dyes were favorable. The contact time required to obtain the equilibrium was 8 and 18 h at 298 K, for Reactive Red 194 and Direct Blue 53, respectively. The Avrami fractionary-order kinetic model provided the best fit to experimental data compared with pseudo-first-order, pseudo-second-order and chemisorption kinetic adsorption models. The equilibrium data were fitted to Langmuir, Freundlich, Sips and Radke-Prausnitz isotherm models. For both dyes the equilibrium data were best fitted to the Sips isotherm model. 相似文献
325.
Correlation estimates from a meta‐analysis of 108 studies including 126 independent samples and nearly 70 000 participants were used to test multiple path models of the antecedents of militant and nonmilitant union participation. Variables moderating the relationship between union commitment and participation were examined. The magnitude of the relationship between commitment and militant participation was moderated by status‐based group membership (i.e., white collar versus blue collar), supporting a contingency model of union participation. Results updated and further developed an integrative model of union participation. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献
326.
Alyson Haslam Sara Wagner Ro Matthew R. Bonner William Lindbl Joey Allegr Ye Shen John E. Vena 《环境科学学报(英文版)》2016,28(3):270-277
Fish from the Great Lakes contain polychlorinated biphenyls(PCBs)which have been shown to disrupt endocrine function and mimic thyroid hormones,but they also contain beneficial omega-3 fatty acids that may offer protection against endocrine cancers.The purpose of this study was to examine the effects of Lake Ontario fish consumption and the estimated consumption of PCBs and omega-3 fatty acids on the risk of thyroid cancer in a group of sport fishermen.Anglers from the New York State Angler Cohort Study were followed for cancer incidence from 1991–2008.Twenty-seven cases of incident thyroid cancer and 108 controls were included in the analyses.Total estimated fish consumption,estimated omega-3 fatty acid consumption,and estimated PCB consumption from Lake Ontario fish were examined for an association with the incidence of thyroid cancer,while matching on sex,and controlling for age and smoking status.Results from logistic regression indicate no significant associations between fish consumption,short-term estimated omega-3 fatty acids,or estimated PCB consumption from Great Lakes fish and the development of thyroid cancer,but it was suggested that long-term omega-3 fatty acid from Great Lakes fish may be protective of the development of thyroid cancer.In conclusion,fish consumption,with the possible concomitant PCBs,from the Great Lakes does not appear to increase the risk of thyroid cancer in New York anglers.Further research is needed in order to separate the individual health effects of PCBs from omega-3 fatty acids contained within the fish. 相似文献
327.
Stephanie J. Perles Tyler Wagner Brian J. Irwin Douglas R. Manning Kristina K. Callahan Matthew R. Marshall 《Environmental management》2014,54(3):641-655
Forests are socioeconomically and ecologically important ecosystems that are exposed to a variety of natural and anthropogenic stressors. As such, monitoring forest condition and detecting temporal changes therein remain critical to sound public and private forestland management. The National Parks Service’s Vital Signs monitoring program collects information on many forest health indicators, including species richness, cover by exotics, browse pressure, and forest regeneration. We applied a mixed-model approach to partition variability in data for 30 forest health indicators collected from several national parks in the eastern United States. We then used the estimated variance components in a simulation model to evaluate trend detection capabilities for each indicator. We investigated the extent to which the following factors affected ability to detect trends: (a) sample design: using simple panel versus connected panel design, (b) effect size: increasing trend magnitude, (c) sample size: varying the number of plots sampled each year, and (d) stratified sampling: post-stratifying plots into vegetation domains. Statistical power varied among indicators; however, indicators that measured the proportion of a total yielded higher power when compared to indicators that measured absolute or average values. In addition, the total variability for an indicator appeared to influence power to detect temporal trends more than how total variance was partitioned among spatial and temporal sources. Based on these analyses and the monitoring objectives of the Vital Signs program, the current sampling design is likely overly intensive for detecting a 5 % trend·year?1 for all indicators and is appropriate for detecting a 1 % trend·year?1 in most indicators. 相似文献
328.
329.
Majaron Vinícius F. da Silva Marisa Gomes Bortoletto-Santos Ricardo Klaic Rodrigo Ribeiro Sidney J. L. Polito Wagner L. Bevilaqua Denise Farinas Cristiane S. Ribeiro Caue 《Journal of Polymers and the Environment》2022,30(6):2602-2613
Journal of Polymers and the Environment - Fertilization is essential to provide suitable conditions for plant development and crop productivity, but the environmental cost of fertilizers is a... 相似文献