首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   173篇
  免费   2篇
  国内免费   9篇
安全科学   5篇
环保管理   92篇
综合类   27篇
基础理论   20篇
污染及防治   10篇
评价与监测   15篇
社会与环境   10篇
灾害及防治   5篇
  2022年   1篇
  2021年   2篇
  2020年   2篇
  2019年   3篇
  2018年   5篇
  2017年   7篇
  2016年   7篇
  2015年   6篇
  2014年   5篇
  2013年   16篇
  2012年   2篇
  2011年   10篇
  2010年   5篇
  2009年   11篇
  2008年   9篇
  2007年   8篇
  2006年   12篇
  2005年   4篇
  2004年   2篇
  2003年   4篇
  2002年   5篇
  2001年   3篇
  2000年   6篇
  1999年   1篇
  1998年   4篇
  1997年   3篇
  1995年   2篇
  1994年   2篇
  1993年   4篇
  1992年   1篇
  1991年   2篇
  1989年   1篇
  1988年   2篇
  1987年   1篇
  1986年   2篇
  1985年   1篇
  1984年   4篇
  1983年   3篇
  1982年   3篇
  1981年   3篇
  1980年   6篇
  1979年   1篇
  1978年   1篇
  1977年   1篇
  1973年   1篇
排序方式: 共有184条查询结果,搜索用时 31 毫秒
181.
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   
182.
Introduction: The objective of this study is to examine sport and recreational (S&R) activity participation and injury rates (IR) in high school students (ages 14–19). Methods: High school students (N = 24 schools, n = 2,029; 958 male, 1,048 female, 23 identified ‘other’ or missing; ages 14–19) in Alberta completed a web-based survey during class (October 2018–March 2019). Students identified their top three sports for participation in the past year. Primary outcome measures included IR for (a) any S&R-related injury, (b) most serious S&R-related injury resulting in medical attention, and (c) most serious injury resulting in restriction from S&R for at least one day. Results: In total, 1763/2029 (86.89%) respondents [861/958 (89.87%) male, 886/1048 (84.54%) female, 16/23 (69.57%) identifying as ‘other’ or missing] participated in an S&R activity in the past year. Top sports for male participation were basketball (33.08%; 95% CI 27.67–39.00), ice hockey (20.46%; 95% CI 14.87–27.47), and soccer (19.42%; 95% CI 15.67–23.80). Top sports for female participation were dance (22.52%; 95% CI 17.98–27.82), basketball (18.32%; 95% CI 14.32–23.14), and badminton (17.84%; 95% CI 13.35–23.43). Of the 1,971 students completing the S&R injury question, 889 reported at least one injury during the past year [(IR = 45.10 injuries/100 students/year (95% CI 39.72–50.61)]. The medical attention IR was 29.09 injuries/100 students/year (95% CI 24.49–34.17) and time loss IR was 36.00 injuries/100 students/year (95% CI 30.47–41.93). Conclusions: High school student S&R IRs are high with 29% of adolescents reporting at least one medical attention injury within the past year. Injury prevention strategies targeting youth are necessary. Practical Application: Participation in S&R activities has multiple physical, psychological, and health benefits for adolescents, but some S&R activities also have greater risks of injury. This study informs the next sports to target for implementation of optimal prospective surveillance and injury prevention strategies among high school aged students.  相似文献   
183.
This study examines the effects of municipal promotion and education (P&E) investments on the recycling rates of recyclables found in Ontario's residential waste stream. Using panel data collected from 223 Ontario municipalities between 2003 and 2012, this study examines whether investments in recycling P&E lead to an increase in household recycling. Investments in recycling promotion and education have been characterized as a policy best practice and is promoted as one of the primary drivers of resource conservation and sustainability in Ontario. Focus is placed on analyzing: (a) the relationship between P&E expenditures and recycling rates in the province, (b) the relationship between municipal recycling rates and P&E investments at different funding levels and (c) the impact of locality on promotion and education efficacy. The results of the statistical regressions indicate that investments in recycling P&E do not increase municipal recycling rates, necessitating a re-evaluation of existing policy and management practices.  相似文献   
184.
Chicken eggs from five different production types (conventional, omega-3 enriched, free range, organic and free run) were collected, when available, from three regions (west, central and east) of Canada to determine persistent organic pollutant (POP) concentrations. Total polychlorinated biphenyl (PCB) concentrations (∑37 congeners) in yolks from the eggs ranged from 0.162 ng g−1 lipid to 24.8 ng g−1 lipid (median 1.25 ng g−1 lipid) while the concentration of the sum of the 6 indicator PCBs ranged from 0.100 ng g−1 lipid to 9.33 ng g−1 lipid (median 0.495 ng g−1 lipid). Total polychlorinated dibenzo-p-dioxin/dibenzofuran (PCDD/F) concentrations ranged from 2.37 pg g−1 lipid to 382 pg g−1 lipid (median 9.53 pg g−1 lipid). The 2005 WHO toxic equivalency (TEQ) ranged from 0.089 pg TEQPCDD/F+dioxin-like[DL]-PCB g−1 lipid to 12.8 pg TEQPCDD/F+DL-PCB g−1 lipid (median 0.342 pg TEQPCDD/F+DL-PCB g−1 lipid). PCB and PCDD/F concentrations were significantly different (p < 0.001) in egg yolks from different regions of collection. In contrast to observations in Europe, PCB and PCDD/F concentrations in Canadian egg yolks were not impacted solely by the production type (e.g., conventional, free range, organic, etc.) used to maintain the laying chickens. Additionally, only one Canadian free range yolk from western Canada (12.8 pg TEQPCDD/F+DL-PCB g−1 lipid) exceeded the European toxic equivalent concentration limits for eggs (5 pg TEQPCDD/F+DL-PCB g−1 lipid). This differs from observations in Europe where free range/home produced eggs frequently have higher POP concentrations than eggs from other production types. Median PCB dietary intake estimates based on consumption of eggs were less than 10 ng d−1 while median PCDD/F intakes were less than 45 pg d−1.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号