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   97184篇
  免费   1416篇
  国内免费   2015篇
安全科学   4054篇
废物处理   3533篇
环保管理   14738篇
综合类   22972篇
基础理论   27359篇
环境理论   73篇
污染及防治   17346篇
评价与监测   5779篇
社会与环境   4029篇
灾害及防治   732篇
  2022年   909篇
  2021年   933篇
  2020年   791篇
  2019年   967篇
  2018年   1280篇
  2017年   1377篇
  2016年   2314篇
  2015年   1989篇
  2014年   2758篇
  2013年   9478篇
  2012年   2562篇
  2011年   2985篇
  2010年   3510篇
  2009年   3636篇
  2008年   2541篇
  2007年   2456篇
  2006年   2696篇
  2005年   2565篇
  2004年   2900篇
  2003年   2703篇
  2002年   2291篇
  2001年   2715篇
  2000年   2272篇
  1999年   1663篇
  1998年   1467篇
  1997年   1462篇
  1996年   1570篇
  1995年   1644篇
  1994年   1530篇
  1993年   1374篇
  1992年   1372篇
  1991年   1325篇
  1990年   1272篇
  1989年   1252篇
  1988年   1093篇
  1987年   1004篇
  1986年   1005篇
  1985年   1083篇
  1984年   1173篇
  1983年   1184篇
  1982年   1182篇
  1981年   1104篇
  1980年   951篇
  1979年   937篇
  1978年   833篇
  1977年   729篇
  1976年   658篇
  1974年   630篇
  1973年   656篇
  1972年   671篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
21.
Journal of Material Cycles and Waste Management - Owing to various advantages of artificial marble compared to natural marble, its application has been rising exponentially, which has resulted in...  相似文献   
22.
23.
24.
Objectives: The accuracy of self-reported driving exposure has questioned the validity of using self-reported mileage to inform research questions. Studies examining the accuracy of self-reported driving exposure compared to objective measures find low validity, with drivers overestimating and underestimating driving distance. The aims of the current study were to (1) examine the discrepancy between self-reported annual mileage and driving exposure the following year and (2) investigate whether these differences depended on age and annual mileage.

Methods: Two estimates of drivers’ self-reported annual mileage collected during vehicle installation (obtained via prestudy questionnaires) and approximated annual mileage driven (based upon Global Positioning System data) were acquired from 3,323 participants who participated in the Strategic Highway Research Program 2 (SHRP2) Naturalistic Driving Study.

Results: A Wilcoxon signed rank test showed that there was a significant difference between self-reported and annual driving exposure during participation in SHRP 2, with the majority of self-reported responses overestimating annual mileage the following year, irrespective of whether an ordinal or ratio variable was examined. Over 15% of participants provided self-reported responses with over 100% deviation, which were exclusive to participants underestimating annual mileage. Further, deviations in reporting differed between participants who had low, medium, and high exposure, as well as between participants in different age groups.

Conclusions: These findings indicate that although self-reported annual mileage is heavily relied on for research, such estimates of driving distance may be an overestimate of current or future mileage and can influence the validity of prior research that has utilized estimates of driving exposure.  相似文献   

25.
26.
27.
28.
29.
Research suggests that encouraging motivated residents to reach out to others in their social network is an effective strategy for increasing the scale and speed of conservation action adoption. However, little is known about how to effectively encourage large numbers of residents to reach out to others about conservation causes. We examined the influence of normative and efficacy-based messaging at motivating residents to engage in and to encourage others to participate in native plant gardening in their community. To do so, we conducted a field experiment with messages on mailings and tracked native plant vouchers used. Efficacy messages tended to be more effective than normative messages at increasing residents’ willingness to reach out to others to encourage conservation action, as indicated by a several percentage point increase in native plant voucher use by residents’ friends and neighbors. Messages sometimes had different impacts on residents based on past behaviors and perceptions related to native plant gardening. Among these subgroups, efficacy and combined efficacy and norm messages most effectively encouraged individual and collective actions, as indicated by increased voucher usage. Our findings suggest that interventions that build residents’ efficacy for engaging in a conservation behavior and for reaching out to others may be a promising path forward for outreach. However, given our results were significant at a false discovery rate cutoff of 0.25 but not 0.05, more experimental trials are needed to determine the robustness of these trends.  相似文献   
30.
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