收费全文 | 4992篇 |
免费 | 429篇 |
国内免费 | 626篇 |
安全科学 | 1056篇 |
废物处理 | 125篇 |
环保管理 | 942篇 |
综合类 | 2599篇 |
基础理论 | 342篇 |
污染及防治 | 374篇 |
评价与监测 | 282篇 |
社会与环境 | 127篇 |
灾害及防治 | 200篇 |
2024年 | 16篇 |
2023年 | 78篇 |
2022年 | 115篇 |
2021年 | 170篇 |
2020年 | 213篇 |
2019年 | 135篇 |
2018年 | 83篇 |
2017年 | 203篇 |
2016年 | 165篇 |
2015年 | 224篇 |
2014年 | 214篇 |
2013年 | 252篇 |
2012年 | 314篇 |
2011年 | 394篇 |
2010年 | 269篇 |
2009年 | 257篇 |
2008年 | 180篇 |
2007年 | 308篇 |
2006年 | 357篇 |
2005年 | 246篇 |
2004年 | 243篇 |
2003年 | 238篇 |
2002年 | 209篇 |
2001年 | 168篇 |
2000年 | 155篇 |
1999年 | 145篇 |
1998年 | 115篇 |
1997年 | 87篇 |
1996年 | 82篇 |
1995年 | 73篇 |
1994年 | 54篇 |
1993年 | 54篇 |
1992年 | 40篇 |
1991年 | 22篇 |
1990年 | 15篇 |
1989年 | 7篇 |
1987年 | 11篇 |
1986年 | 13篇 |
1985年 | 9篇 |
1984年 | 6篇 |
1983年 | 9篇 |
1982年 | 10篇 |
1981年 | 7篇 |
1980年 | 16篇 |
1979年 | 10篇 |
1978年 | 10篇 |
1977年 | 6篇 |
1974年 | 5篇 |
1973年 | 5篇 |
1971年 | 9篇 |
Objective: The objective of this study was to provide additional evidence that posture control is negatively affected at BACs greater than 0.06 g/dL or breath alcohol concentrations (BrACs) of 0.06 g/210 L.
Method: This was a between-subjects study, with BrAC group as the independent variable (5 levels: 0.00, 0.04, 0.06, 0.08, and 0.10 g/210 L); 4 measures of postural control as the dependent variables; and age, height, and weight as the covariates. Posture control was measured with a force-sensing platform connected to a computer. The feet's center of pressure (CoP) on the platform was recorded and the corresponding movement of the body in the anterior–posterior and lateral planes was derived. Participants (N = 96) were randomly assigned to one of the BrAC groups. Positive BrAC groups were compared to the zero BrAC group. Data were examined with hierarchical multiple regression.
Results: Adjusted for age, height, and weight, the main effect of lateral CoP with eyes open was not statistically significant. There was a statistically significant main effect of alcohol on anterior–posterior CoP excursion with eyes open and with eyes closed and lateral CoP excursion with eyes closed. For all 3 of those variables, only BrACs of 0.08 and 0.10 g/210 L produced differences against zero BrAC. Although the main effect of alcohol on Lateral CoP Excursion with eyes open was not statistically significant, the contrasts between 0 and 0.08 and 0 and 0.10 g/210L BrAC were in the hypothesized direction.
Conclusion: The current study did not directly address the issue of whether the sobriety tests are sensitive to BrACs of 0.05 g/210 L or above; rather, it provides additional evidence that postural control, one of the components of those tests, is relatively unaffected by BrACs lower than 0.08 g/210 L. Additional research is needed on the diagnostic characteristics of the sobriety tests at BrACs lower than 0.08 g/210 L. 相似文献