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   318篇
  免费   2篇
  国内免费   6篇
安全科学   10篇
废物处理   19篇
环保管理   40篇
综合类   58篇
基础理论   65篇
污染及防治   96篇
评价与监测   17篇
社会与环境   19篇
灾害及防治   2篇
  2023年   5篇
  2022年   10篇
  2021年   18篇
  2020年   8篇
  2019年   8篇
  2018年   5篇
  2017年   11篇
  2016年   11篇
  2015年   17篇
  2014年   17篇
  2013年   20篇
  2012年   17篇
  2011年   22篇
  2010年   16篇
  2009年   24篇
  2008年   11篇
  2007年   12篇
  2006年   18篇
  2005年   15篇
  2004年   12篇
  2003年   8篇
  2002年   11篇
  2001年   4篇
  2000年   2篇
  1998年   1篇
  1997年   2篇
  1996年   2篇
  1995年   3篇
  1993年   4篇
  1992年   1篇
  1991年   1篇
  1989年   2篇
  1986年   1篇
  1983年   1篇
  1981年   1篇
  1966年   1篇
  1964年   1篇
  1962年   1篇
  1960年   1篇
  1958年   1篇
排序方式: 共有326条查询结果,搜索用时 15 毫秒
161.
Social insect workers mature behaviorally and physiologically with increasing age, generally transitioning from or adding new tasks to their existing repertoire of within-nest nursing tasks. As adult minor workers of the ant Pheidole dentata age, they attend to brood more frequently and nurse more efficiently, perform a broader array of tasks, and undergo myological and neural development. Because these factors covary, the causal relationships among age, task experience, and neural and physiological maturation are not understood. We compared brood-care performance and efficiency by 10-day-old P. dentata minors that had acquired nursing experience to that of equal-age minors experimentally deprived of brood contact. We found the frequency and efficiency of nursing did not significantly differ between experimental and control worker groups, suggesting experience is not required for age-related improvement in nursing efficiency. Workers with and without prior nursing experience did not significantly differ macroscopically in brain anatomy or in brain serotonin content, although workers from the two treatments had slightly, but significantly, different levels of brain dopamine. These results suggest experience with brood is not required for P. dentata minor workers to develop nursing proficiency or undergo a substantial degree of the age-related neural development identifiable by our assessments, which could underscore the ontogeny of brood-care efficiency.  相似文献   
162.
163.
164.
IntroductionSafety participation is of paramount importance in guaranteeing the safe running of nuclear power plants.MethodThe present study examined the effects of empowering leadership on safety participation.ResultsBased on a sample of 495 employees from two Spanish nuclear power plants, structural equation modeling showed that empowering leadership has a significant relationship with safety participation, which is mediated by collaborative team learning. In addition, the results revealed that the relationship between empowering leadership and collaborative learning is partially mediated by the promotion of dialogue and open communication.ConclusionsThe implications of these findings for safety research and their practical applications are outlined.Impact on IndustryAn empowering leadership style enhances workers' safety performance, particularly safety participation behaviors. Safety participation is recommended to detect possible rule inconsistencies or misunderstood procedures and make workers aware of critical safety information and issues.  相似文献   
165.
Animals adopt different strategies to communicate by means of sound in noisy environments. Some animals increase, while others decrease, their vocal activity in the presence of interference. Anuran amphibians from diverse latitudes exhibit both kinds of responses. Recent studies have shown that males of Batrachyla taeniata and Batrachyla antartandica from the temperate austral forest do not call in response to the presentation of advertisement calls of sympatric congeneric species, but their responsiveness to other kinds of interference has not been tested. To explore the diversity in responsiveness to acoustic intrusion in a single species, we exposed males of B. taeniata to prolonged prerecorded natural abiotic noises of wind, creek, and rain and to a band-pass noise centered at 2,000 Hz, at 67 dB sound pressure level (SPL). The subjects drastically increased their call rate when exposed to all four sounds. Frogs also responded by augmenting their vocal activity to exposures of band-pass noise at increasing intensities (55–79 dB SPL). The increase in vocal activity in response to noise is strong relative to those of other anurans from the temperate forest studied previously under similar exposures. These results reveal a remarkable activation of vocal response to acoustic interference of continuous abiotic noise, which would allow compensating for limitations in the active communication space under background sounds. This strategy contrasts with the decrease in vocal output amid interference from heterospecific signals reported formerly for this frog, a tactic that would restrict energy expenditure to relevant acoustic competition with conspecifics.  相似文献   
166.
Journal of Polymers and the Environment - The current global proposal for withdrawing polymers with high resistance to degradation and from fossil sources from disposable appliances, as well as the...  相似文献   
167.
168.
169.
As part of a study of the predictive utility of employee preferences for forms of supervisory inducements, a sample of 236 administrators and first-line supervisors provided survey data regarding their individual superiors. The respondents' statements of preferred forms of social influence from their superiors were statistically adjusted for the reported level of influence used in order to determine more precisely whether discrepancies between actual and preferred forms of influence could uniquely predict criterion variance. Results indicated that these adjusted discrepancy values were inversely correlated with satisfaction with supervision, ingroup status, and superior's considerate-ness. These supportive results suggest that discrepancies between preferences for inducements and reported forms of influence may be an important ingredient in a fuller explanation of the phenomenon of motivation and leadership.  相似文献   
170.
Chile is one of the most seismically active countries in the world. Earthquakes are periodic phenomena that test the quality of construction, as well as the capacity of the population to adapt to sharp changes in socio-environ-mental conditions.
Experience in this regard has demonstrated the desirability of being prepared, at the institutional level and at the level of the general population, to carry out investigations and to begin measures to cope with these catastrophes, in order to reduce damage and the interruption of normal life to a minimum.
In this paper some general aspects of the social and health impacts of the earthquake of 3rd March 1985 are examined. The shock affected the central area of Chile which contains 61% of the total population.
The earthquake occurred at 19:50 hours on Sunday, 3rd March, and was of magnitude 7.8. Recorded personal losses included 180 dead and 2,575 injured, and around 200,000 damaged or destroyed dwellings. The destruction also affected the infrastructure of the public services, such as energy, road, telecommunications and water supply, giving rise to an emergency in the provision of assistance.
Special reference is made to the effects, on the health care infrastructure, drinking water supply and, less important, on the behavior of some communicable intestinal diseases that are highly endemic in the area under study.  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