首页 | 官方网站   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   251篇
  免费   8篇
  国内免费   2篇
环境安全   261篇
  2023年   1篇
  2022年   4篇
  2021年   2篇
  2020年   3篇
  2019年   1篇
  2018年   7篇
  2017年   10篇
  2016年   4篇
  2015年   2篇
  2014年   3篇
  2013年   20篇
  2012年   14篇
  2011年   14篇
  2010年   15篇
  2009年   8篇
  2008年   17篇
  2007年   16篇
  2006年   13篇
  2005年   15篇
  2004年   12篇
  2003年   13篇
  2002年   8篇
  2001年   3篇
  2000年   6篇
  1999年   7篇
  1998年   3篇
  1997年   2篇
  1996年   2篇
  1995年   2篇
  1994年   6篇
  1993年   2篇
  1992年   1篇
  1991年   1篇
  1988年   2篇
  1987年   2篇
  1986年   2篇
  1985年   3篇
  1984年   1篇
  1983年   2篇
  1982年   5篇
  1981年   2篇
  1977年   3篇
  1976年   1篇
  1960年   1篇
排序方式: 共有261条查询结果,搜索用时 109 毫秒
71.
The health of populations in industrialised societies has been affected for many years by ambient air pollutants presenting a threat of chronic bronchitis and lung cancer. In the 1980s Indoor pollutants received much needed investigation to assess their hazards to health. Exposure to environmental tobacco smoke and radon is now the subject of much research and concern. This review attempts to put some perspective on lung cancer that is attributable to lifetime exposure to airborne pollutants. The view is expressed that air pollution control authorities have played and are playing a major role in health improvement.  相似文献   
72.
73.
PROBLEM: Although graduated driver licensing (GDL) programs have reduced the high crash rates for 16-and 17-year-old drivers, research suggests that some teenagers fail to comply with restrictions on nighttime driving and carrying passengers. METHOD: A program to encourage compliance with GDL restrictions and seat belt requirements was implemented in Guilford County, North Carolina. The program combined increased enforcement with a multi-faceted publicity campaign drawing attention to the enforcement activity. A comparison community was studied to assess whether changes over time could be reasonably attributed to the program. RESULTS: Several measures indicate that greater enforcement did occur in the intervention community and that teenagers perceived the increase. However, self-reported data and direct observations of young drivers in the intervention and comparison communities showed the program resulted in only modest changes in compliance with GDL restrictions. DISCUSSION: The program put in place the mechanisms known to produce changes in driver behavior, but these may have been insufficient to alter the behavior of the minority of teenagers (and parents) who were not already complying with restrictions. However, the modest changes in young driver behavior plus the clear changes in both actual and perceived enforcement suggest that high visibility enforcement programs merit further use and evaluation in other communities, particularly those where compliance with GDL provisions is lower than in Guilford County.  相似文献   
74.
INTRODUCTION: Progress in dealing with the alcohol-impaired driving problem in the United States during the past 25 years is addressed. METHODS: Trends in various measures of the problem were tracked and a thorough review of the relevant literature conducted. RESULTS: In the 1980s and continuing into the early 1990s, major decreases occurred in alcohol-impaired driving and its consequences. The contribution of alcohol to fatal crashes dropped by 35-40% during this period. Two primary reasons for the decline appear to be the emergence of citizen activist groups that mobilized public support and attention to the problem, and the proliferation of effective laws. Since about 1995 the alcohol-impaired driving problem has stabilized at a reduced but still quite high level. CONCLUSIONS: Highway safety organizations and citizen activist groups have continued to highlight the problem, but its status as a social issue has diminished. We basically know what the primary target groups are, and we know measures that would work to reduce the problem if implemented more fully. We know that political leadership, state task forces, and media advocacy are important ingredients in addressing the problem. It is likely that a resurgence in citizen activism will be necessary to foster these elements and refocus the nation on the unfinished battle against alcohol-impaired driving. IMPACT ON INDUSTRY: Alcohol-impaired driving is still a major problem that needs continuing attention.  相似文献   
75.
76.
A study was undertaken in North Carolina to determine the characteristics of the minority of drivers who were not using seat belts following an extensive publicity/enforcement campaign, which had increased statewide use to 80%. Vehicles and drivers whose seat belt use was observed at sites across North Carolina were matched against Division of Motor Vehicles registration and driver history files for vehicle owners. The study file consisted of those observed drivers who matched the owners with respect to sex, race, and approximate age. The results of this investigation indicate that nonuse of seat belts was associated with males; younger age (<35); older vehicles (pre-1985); vehicles other than cars, especially pickups; and poor driving records. Telephone survey information indicated that nonusers were less likely to have health care coverage, more likely to acknowledge having consumed large amounts of alcohol in the past year, and more likely to have an arrest record. When asked about enforcement of the belt use law, many nonusers said that they would not respond to higher fines but they would respond to driver license points. To change the belt use behavior of this hard-core nonuser population, it well may be necessary as was done in Canada to combine publicity/enforcement campaigns with driver license points as a penalty for nonuse.  相似文献   
77.
Integrated rice-fish culture: Coupled production saves resources   总被引:9,自引:0,他引:9  
Rice is a key component in global food security, as it is the main ingredient in the daily diets of around 3 billion people, especially in Asia. Like all agricultural production, rice cultivation depends on scarce natural resources. This article briefly outlines the utilization of land and water in rice production, and suggests an approach for optimizing use efficiency, namely through the combination of rice and fish culture. The authors argue that the utilization of land and fresh water is optimized through integrated and complementary production of rice and fish — two basic foods items in daily local diets. The article reviews currently available scientific literature on integrated rice‐fish systems. Rice‐fish culture systems are briefly characterized, and respective yield potential and interactions between rice and fish are discussed. Results of socio‐economic surveys regarding the adoption of integrated rice‐fish culture are summarized. The article also reviews literature on the impact of fish culture on rice field ecology as outlined in studies on weed infestation, insect populations, and greenhouse gas emissions. The article concludes that rice‐fish culture can be an option to help rice producing countries keep pace with soaring domestic demand for food, especially fish. Integrated rice and fish culture optimizes the benefits of scarce land and water resources through complementary use, and exploits the synergies between fish and plant.  相似文献   
78.
In recent model years, Ford vehicles have been equipped with a supplementary seat belt reminder system that flashes and chimes intermittently for up to 5 min if the driver is unbelted. Sound- and light-based belt reminder systems of various types are beginning to appear in the market place, and it is important to learn about their acceptance and ability to increase belt use. The present study was designed to ascertain consumer reaction and reported belt use regarding the Ford system. Personal interviews were conducted with 405 drivers of vehicles with the reminder system. Among the drivers, 67% said they had activated the belt reminder one or more times, 73% said that the last time this happened they fastened their belts, 46% said their belt use had increased since driving this vehicle, 78% said they liked the reminder system, and 79% said they wanted a reminder system like this in their next vehicle. Five percent had disabled the system. Part-time users were responsive to the reminder, for example, of those who said they currently used belts usually but not on some occasions, 70% said they fastened their seat belts the last time the reminder was activated and 76% said their belt use had increased. Five percent spontaneously mentioned the belt reminder as an especially disliked feature of their new vehicles, and 2% said their belt use had decreased since having it. The 7% of respondents who reported they used belts never or very occasionally were least responsive to the system. Overall, the Ford belt reminder system is being favorably received.  相似文献   
79.
The Environmental Impact Statement (EIS) attempts to portray the current character of a given ecosystem. This provides a Baseline against which future possible changes can be assessed. Ecosystems, however, are dynamic and in a constant state of change. Consequently, data representing a single year reflect conditions only for that year and can be misleading if compared against any other year. In addition to this temporal variation, considerable spacial variation exists in species composition and cover. Ample sampling is required to compensate for this heterogeneity. Variation, or background noise, can be minimized by the use of similarity indexes and sampling over a period of at least two years.  相似文献   
80.
The purpose of this research was to elicit and compare the open-space preferences of citizens and openspace experts in Albuquerque, New Mexico, USA. A randomly selected sample of 492 citizens and 35 open-space experts participated in a telephone survey during May 5–18, 1986. The following hypothesis was tested and used as a guideline for the study:HO1: There is no significant difference between respondents' status and preference for open space in Albuquerque, New Mexico.The hypothesis was rejected. Findings confirmed respondents' status affected preference for open space. Of the eight issues on which the citizen and expert groups were compared, five recorded significant differences in response profiles. The open-space expert group was significantly more supportive of using open space to accommodate offroad vehicle facilities, wildlife preserves, a citywide recreational trail, and a trail system along the arroyos and city ditches. The citizen sample was significantly more supportive of using open space to accommodate overnight camping facilities. Both groups equally supported using open space to accommodate an outdoor amphitheater, outdoor education facilities, and rafting, kayaking, and canoeing facilities.The finding indicated that expert preferences did not represent an aggregate of citizen preferences for managing open-space resources. Understanding both expert and citizen positions will facilitate decision-making processes and help resolve environmental disputes.  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-23

京公网安备 11010802026262号