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   648篇
  免费   6篇
  国内免费   2篇
安全科学   36篇
废物处理   22篇
环保管理   118篇
综合类   114篇
基础理论   135篇
环境理论   1篇
污染及防治   179篇
评价与监测   32篇
社会与环境   15篇
灾害及防治   4篇
  2022年   7篇
  2021年   12篇
  2020年   12篇
  2019年   5篇
  2018年   3篇
  2017年   11篇
  2016年   19篇
  2015年   21篇
  2014年   29篇
  2013年   45篇
  2012年   26篇
  2011年   48篇
  2010年   35篇
  2009年   21篇
  2008年   27篇
  2007年   43篇
  2006年   38篇
  2005年   25篇
  2004年   35篇
  2003年   22篇
  2002年   17篇
  2001年   4篇
  1999年   8篇
  1998年   4篇
  1997年   6篇
  1995年   3篇
  1994年   8篇
  1993年   8篇
  1992年   4篇
  1991年   4篇
  1990年   3篇
  1989年   5篇
  1988年   4篇
  1987年   4篇
  1983年   3篇
  1982年   5篇
  1980年   5篇
  1979年   3篇
  1972年   3篇
  1961年   3篇
  1952年   2篇
  1940年   3篇
  1939年   2篇
  1937年   2篇
  1930年   2篇
  1928年   2篇
  1926年   3篇
  1923年   2篇
  1914年   3篇
  1913年   4篇
排序方式: 共有656条查询结果,搜索用时 281 毫秒
531.
Objective: The objective of this study was to estimate the safety benefits of in vehicle lane departure warning (LDW) and lane keeping aid (LKA) systems in reducing relevant real-world passenger car injury crashes.

Methods: The study used an induced exposure method, where LDW/LKA-sensitive and nonsensitive crashes were compared for Volvo passenger cars equipped with and without LDW/LKA systems. These crashes were matched by car make, model, model year, and technical equipment; that is, low-speed autonomous emergency braking (AEB) called City Safety (CS). The data were extracted from the Swedish Traffic Accident Data Acquisition database (STRADA) and consisted of 1,853 driver injury crashes that involved 146 LDW-equipped cars, 11 LKA-equipped cars, and 1,696 cars without LDW/LKA systems.

Results: The analysis showed a positive effect of the LDW/LKA systems in reducing lane departure crashes. The LDW/LKA systems were estimated to reduce head-on and single-vehicle injury crashes on Swedish roads with speed limits between 70 and 120 km/h and with dry or wet road surfaces (i.e., not covered by ice or snow) by 53% with a lower limit of 11% (95% confidence interval [CI]). This reduction corresponded to a reduction of 30% with a lower limit of 6% (95% CI) for all head-on and single-vehicle driver injury crashes (including all speed limits and all road surface conditions).

Conclusions: LDW/LKA systems were estimated to lower the driver injury risk in crash types that the systems are designed to prevent; that is, head-on and single-vehicle crashes. Though these are important findings, they were based on a small data set. Therefore, further research is desirable to evaluate the effectiveness of LDW/LKA systems under real-world conditions and to differentiate the effectiveness between technical solutions (i.e., LDW and LKA) proposed by different manufacturers.  相似文献   

532.
Zur Verwendung von Mikroalgen für Ernährungszwecke   总被引:2,自引:0,他引:2  
  相似文献   
533.
534.
Objective To develop a theoretical framework for analysing ethnic differences in determinants of participation and non-participation in prenatal screening for Down syndrome. Methods We applied Weinstein's Precaution Adoption Process (PAP) Model to the decision of whether or not to participate in prenatal screening for Down syndrome. The prenatal screening stage model was specified by reviewing the empirical literature and by data from seven focus group interviews with Dutch, Turkish and Surinamese pregnant women in the Netherlands. Results We identified 11 empirical studies on ethnic differences in determinants of participation and non-participation in prenatal screening for Down syndrome. The focus group interviews showed that almost all stages and determinants in the stage model were relevant in women's decision-making process. However, there were ethnic variations in the relevance of determinants, such as beliefs about personal consequences of having a child with Down syndrome or cultural and religious norms. Discussion The prenatal screening stage model can be applied as a framework to describe the decision-making process of pregnant women from different ethnic backgrounds. It provides scope for developing culturally sensitive, tailored methods to guide pregnant women towards informed decision-making on participation or non-participation in prenatal screening for Down syndrome. Copyright © 2007 John Wiley & Sons, Ltd.  相似文献   
535.
536.
Scientific debates on environmental impacts in cost-benefit analysis (CBA) focus on methodological questions. The literature, however, contains very little information on the influence of these debates on CBAs made in spatial planning practice. In this paper, this gap is filled by a qualitative analysis of 67 CBAs made in the Netherlands between 2000 and 2011. From the literature on environmental valuation, we derive criteria to evaluate the quality of CBA practice, such as completeness and the inclusion of uncertainties. The analysis shows that in many cases relevant environmental effects are omitted or not monetised. Moreover, non-monetised effects are often not included in CBA conclusions. If impacts are monetised, the methods used are frequently not very sophisticated. The consequences of assumptions are often not communicated, for example, where high discount rates make long-term effects seem unimportant. In this research we identify four main points for good practice.  相似文献   
537.
538.
OBJECTIVE: Smoking has been linked to disease and injury. The purpose of this study is to investigate the smoking habits of motor vehicular driver trauma center patients and their association with previous injury history and risky behaviors. METHODS: The studied population included 323 motor vehicular driver injury patients (123 smokers and 200 non-smokers) interviewed as part of a larger study of psychoactive substance use disorders at an adult Level I trauma center. Patients with head injuries, hospital stays of less than two days, and diminished cognition were excluded. Interviews included demographics (age, gender, race, marital status), socioeconomic status (SES; income, education, employment), risky behaviors (seatbelt non-use, drinking and driving, riding with drunk driver, binge drinking), and trauma history information (vehicular, assault, and other injuries). Substance abuse (alcohol and drug dependence) was evaluated in depth using DSM III-R criteria. Smokers and non-smokers were compared in relation to control and dependent variables using student's t test and chi-square (alpha = 0.05). Outcome variables included previous trauma history and risky behaviors. Multiple logistic regression models using step-down selection methods (alpha = 0.05) were constructed with risky behaviors and trauma history as dependent variables including demographics, SES and substance as independent variables. RESULTS: Smokers represented 38 percent of the 323 patients studied. Smokers (n = 123) were younger (34 vs. 43 years), more likely to be male (72 percent vs. 50 percent), not married (72 percent vs. 56 percent), and had higher rates of alcohol (29 percent vs. 9 percent) and drug dependence (14 percent vs. 3 percent) than non-smokers (n = 200). Educational achievement (20 percent vs. 15 percent less than high school) and income level (24 percent vs. 23 percent with less than $15,000 of yearly income) were not different between smokers and non-smokers. Smokers were more likely than non-smokers to have a history of prior vehicular trauma (48 percent vs. 26 percent), assault (25 percent vs. 9 percent), or other injury (50 percent vs 37 percent). The following injury-prone behaviors were also more common among the smokers than non-smokers: seatbelt non-use (49 percent vs. 29 percent), drinking and driving (38 percent vs. 15 percent), riding with drunk driver (38 percent vs. 13 percent), and binge drinking (68 percent vs. 26 percent). In multiple logistic regression models adjusting for demographics, SES, and substance abuse, smoking revealed significantly higher odds ratios (OR) for the following dependent variables: seatbelt non-use (OR = 2.9), riding with drunk driver (OR = 2.2), binge drinking (OR = 2.4), previous vehicular (OR = 2.0), and assault injuries (OR = 2.5). Smoking did not reach significance for drinking and driving and other (non-vehicular and non-assault) injury. CONCLUSION: Smoking is independently associated with risky behaviors and repeated history of vehicular or assault injury within the vehicular trauma population.  相似文献   
539.
The application of direct-flame incineration to successfully eliminate a smoke-oil-mist and odor problem in the manufacture of rubber-base rug underlay, is presented. The investigation of various air pollution control processes leading to the development and adoption of the direct-flame incineration system, is covered. The rug-underlay curing process incorporating the direct-flame incineration system with primary heat recovery is described. Results and discussion of a source test to determine the effectiveness of direct-flame incineration in this application are included.  相似文献   
540.
Occupational exposure to cobalt‐containing dust may cause a severe type of pneumoconiosis as well as obstructive lung disease. Peroral exposure to cobalt chloride may under certain circumstances precipitate cardiomyopathy.

There are only a limited number of experimental studies available which deal with the carcinogenic, mutagenic and teratogenic effects of cobalt and its salts. Single or repeated injections of cobalt powder or cobalt chloride have been shown to induce malignant tumours at the site of injection in rats, but not in mice. In vitro studies have shown that cobalt chloride has mutagenic and teratogenic properties. There are no data available on cancer incidence among workers occupationally exposed to cobalt. Thus the possible role of cobalt in human carcinogenesis is still an open question.  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