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   105篇
  免费   7篇
  国内免费   1篇
安全科学   31篇
废物处理   1篇
环保管理   22篇
综合类   10篇
基础理论   33篇
污染及防治   5篇
社会与环境   7篇
灾害及防治   4篇
  2023年   7篇
  2022年   1篇
  2021年   4篇
  2020年   4篇
  2019年   3篇
  2018年   2篇
  2017年   5篇
  2016年   7篇
  2015年   1篇
  2014年   4篇
  2013年   4篇
  2012年   7篇
  2011年   7篇
  2010年   4篇
  2009年   11篇
  2008年   7篇
  2007年   7篇
  2006年   5篇
  2005年   3篇
  2004年   2篇
  2003年   1篇
  1999年   1篇
  1998年   3篇
  1997年   3篇
  1996年   3篇
  1995年   2篇
  1994年   3篇
  1985年   1篇
  1982年   1篇
排序方式: 共有113条查询结果,搜索用时 15 毫秒
21.
了解和掌握毕业生的就业意向,对于更好地开展就业指导服务、促进大学生就业起到很重要的作用。从就业地区、就业单位、就业信息渠道等方面,对社区管理与服务专业毕业生的就业意向进行调查和分析,提出应该转变毕业生就业观念,对毕业生进行就业心理指导,学校应积极开拓东南沿海地区就业市场,提高就业指导和服务水平,加强专业建设等对策。  相似文献   
22.
Two computational methods were applied to classification of movement patterns of zebrafish (Danio rerio) to elucidate Markov processes in behavioral changes before and after treatment of formaldehyde (0.1 mg/L) in semi-natural conditions. The complex data of the movement tracks were initially classified by the Self-organizing map (SOM) to present different behavioral states of test individuals. Transition probabilities between behavioral states were further evaluated to fit Markov processes by using the hidden Markov model (HMM). Emission transition probability was also obtained from the observed variables (i.e., speed) for training with the HMM. Experimental transition and emission probability matrices were successfully estimated with the HMM for recognizing sequences of behavioral states with accuracy rates in acceptable ranges at central and boundary zones before (77.3-81.2%) and after (70.1-76.5%) treatment. A heuristic algorithm and a Markov model were efficiently combined to analyze movement patterns and could be a means of in situ behavioral monitoring tool.  相似文献   
23.
We performed male attraction experiments and staged courtship sequences to test for non-random mating with respect to social behavioral phenotype in the comb-footed spider, Anelosimus studiosus. While asocial behavior is the dominant phenotype in all A. studiosus populations examined to date, a social phenotype approaches a frequency of 15% in colder environments. We collected test subjects from higher latitude polymorphic populations and scored all individuals as to their behavioral phenotype prior to their use in these trials. Males of both phenotypes differentially approached and courted social females over asocial females and no-spider controls. By offering males different numbers of females of one type vs. the other in subsequent trials, we determined that the difference in attractiveness between the two phenotypes social/asocial is 1.5/1. Both the web produced by a female and a female that has been removed from its web attract males. We suggest that the male attracting pheromone is present on females and is also attached to silk threads. Staged encounters completed between males and females of the respective phenotypes demonstrated that courting males suffer significantly less pre-copulatory sexual cannibalism with social females than with asocial ones, and thus, female social tendency is phenotypically linked to sexual aggression. We propose that the male preference for social females is adaptive because of the observed asymmetry in courtship success.  相似文献   
24.
Miners' unsafe behavior (UB) is the main cause of coal mine accidents. Previous research has suggested that excessive noise in tunnels impacts miners' temperaments and safe production behavior. To explore the influence of noise on UB, four different dimensions of noise annoyance were identified: cognitive, emotional, communication, and physical mechanism annoyance. The coal mine noise annoyance scale, miners' unsafe behavior intention (UBI) scale, and miners’ UB scale were developed according to different dimensions. In the first survey, a total of 200 questionnaires were distributed in the two coal mines, and 193 valid questionnaires were recovered. Exploratory factor analysis was conducted, and invalid items were removed according to the analysis results to form the final scale. Then, 500 final scales were distributed in two Chinese coal mines, and 482 valid questionnaires were collected. Confirmatory factor analysis was conducted by collating the data of the second questionnaire. Based upon the structural equation model (SEM), the SEM of the influence of noise annoyance degree on UB and the path analysis with latent variable path analysis with the latent variables (PA-LVs) mediating model of the effect of UBI on UB were established, and the path coefficients with fitting data of the model were analyzed. The results indicated that the four dimensions of coal mine noise annoyance had a strong positive impact on UB, which was reduced by less noise annoyance. In addition, the Bootstrap method was used to verify the mediating method among the four dimensions of noise annoyance, cognitive annoyance, emotional annoyance, with communication annoyance indirectly affecting UB through UBI. The research results provide theoretical support for reducing the UB of miners and improving coal mine safety levels.  相似文献   
25.
The age at which worker honey bees begin foraging varies under different colony conditions. Previous studies have shown that juvenile hormone (JH) mediates this behavioral plasticity, and that worker-worker interactions influence both JH titers and age at first foraging. These results also indicated that the age at first foraging is delayed in the presence of foragers, suggesting that colony age demography directly influences temporal division of labor. We tested this hypothesis by determining whether behavioral or physiological development can be accelerated, delayed, or reversed by altering colony age structure. In three out of three trials, earlier onset of foraging was induced in colonies depleted of foragers compared to colonies depleted of an equal number of bees across all age classes. In two out of three trials, delayed onset of foraging was induced in colonies in which foragers were confined compared to colonies with free-flying foragers. Finally, in three out of three trials, both endocrine and exocrine changes associated with reversion from foraging to brood care were induced in colonies composed of all old bees and devoid of brood; JH titers decreased and hypopharyngeal glands regenerated. These results demonstrate that plasticity in age-related division of labor in honey bee colonies is at least partially controlled by social factors. The implications of these results are discussed for the recently developed ‘‘activator-inhibitor” model for honey bee behavioral development. Received: 8 November 1995/Accepted after revision: 10 May 1996  相似文献   
26.
There have been numerous reports of genetic influences on division of labor in honey bee colonies, but the effects of worker genotypic diversity on colony behavior are unclear. We analyzed the effects of worker genotypic diversity on the phenotypes of honey bee colonies during a critical phase of colony development, the nest initiation phase. Five groups of colonies were studied (n = 5–11 per group); four groups had relatively low genotypic diversity compared to the fifth group. Colonies were derived from queens that were instrumentally inseminated with the semen of four different drones according to one of the following mating schemes: group A, 4 A-source drones; group B, 4 B-source drones; group C, 4 C-source drones; group D, 4 D-source drones; and group E, 1 drone of each of the A-D drone sources. There were significant differences between colonies in groups A-D for 8 out of 19 colony traits. Because the queens in all of these colonies were super sisters, the observed differences between groups were primarily a consequence of differences in worker genotypes. There were very few differences (2 out of 19 traits) between colonies with high worker genotypic diversity (group E) and those with low diversity (groups A-D combined). This is because colonies with greater diversity tended to have phenotypes that were average relative to colonies with low genotypic diversity. We hypothesize that the averaging effect of genotypic variability on colony phenotypes may have selective advantages, making colonies less likely to fail because of inappropriate colony responses to changing environmental conditions.  相似文献   
27.
王晓楠 《中国环境科学》2020,40(8):3495-3505
运用计划行为理论和A-B-C理论,结合强政策背景下上海垃圾分类的实际,完善居民生活垃圾分类行为测量量表,改进并区分居民垃圾分类目标意愿和执行意愿,构建城市居民垃圾分类行为影响路径理论模型.基于“2019年上海居民垃圾分类行为”调查数据,覆盖上海16个区县的2555有效样本,运用结构方程模型验证强政策背景下居民环境态度、主观规范和感知行为控制对垃圾分类行为影响路径.结果表明:环境态度、主观规范、感知行为控制分别对居民垃圾分类目标意愿和执行意愿有显著正向的影响.环境态度分别通过目标意愿和执行意愿对垃圾分类行为产生间接效应.主观规范和感知行为控制并没有通过两类意愿对垃圾分类行为产生间接效应.垃圾分类的政策效能感在目标意愿对垃圾分类行为效应中起到了调节作用.虽然环境态度、主观规范、感知行为控制可以促进公众垃圾分类行为目标意愿和执行意愿的形成,但仅有环境态度可以通过激发公众目标意愿和执行意愿进而形塑居民垃圾分类行为.  相似文献   
28.
在前人研究成果的基础上,选择认知水平、同事顾虑、上级领导抵触、利己考虑、集体考虑、系统本身、安全文化7个影响因素,并依据SCASS分类标准,将上报意愿分为6个维度(报告提交经验、航空器不良运行或设备缺陷报告提交意愿、自身违规差错报告提交意愿、空防安全事件或隐患报告提交意愿、执行标准或飞行程序困难事件报告提交意愿、同事发生此类事件报告提交意愿),构建并验证个体自愿上报意愿的影响因素模型。研究发现,各类事件上报意愿分别受到不同的因素影响,其中,认知水平和安全文化对上报意愿起到正向影响,其他影响因素起到负向影响。本研究为民航单位针对性提高员工上报意愿提供理论指导。  相似文献   
29.
Longitudinal behavioral data generally contains a significant amount of structure. In this work, we identify the structure inherent in daily behavior with models that can accurately analyze, predict, and cluster multimodal data from individuals and communities within the social network of a population. We represent this behavioral structure by the principal components of the complete behavioral dataset, a set of characteristic vectors we have termed eigenbehaviors. In our model, an individual’s behavior over a specific day can be approximated by a weighted sum of his or her primary eigenbehaviors. When these weights are calculated halfway through a day, they can be used to predict the day’s remaining behaviors with 79% accuracy for our test subjects. Additionally, we demonstrate the potential for this dimensionality reduction technique to infer community affiliations within the subjects’ social network by clustering individuals into a “behavior space” spanned by a set of their aggregate eigenbehaviors. These behavior spaces make it possible to determine the behavioral similarity between both individuals and groups, enabling 96% classification accuracy of community affiliations within the population-level social network. Additionally, the distance between individuals in the behavior space can be used as an estimate for relational ties such as friendship, suggesting strong behavioral homophily amongst the subjects. This approach capitalizes on the large amount of rich data previously captured during the Reality Mining study from mobile phones continuously logging location, proximate phones, and communication of 100 subjects at MIT over the course of 9 months. As wearable sensors continue to generate these types of rich, longitudinal datasets, dimensionality reduction techniques such as eigenbehaviors will play an increasingly important role in behavioral research. This contribution is part of the special issue “Social Networks: new perspectives” (Guest Editors: J. Krause, D. Lusseau and R. James). An erratum to this article can be found at  相似文献   
30.
Introduction: The paper presents three intervention studies designed to modify supervisory monitoring and rewarding of subordinates' safety performance. Method: Line supervisors received weekly feedback concerning the frequency of their safety-oriented interactions with subordinates, and used this to self-monitor progress toward designated improvement goals. Managers higher up in the organizational hierarchy received the same information, coupled with synchronous data concerning the frequency of workers' safety behaviors, and highlighting co-variation of supervisory action and workers' behavior. Results: In all the companies involved, supervisory safety-oriented interaction increased significantly, resulting in significant changes in workers' safety behavior and safety climate scores. Continued improvement during the post-intervention period suggests the inclusion of workers' safety behavior as in-role supervisory responsibility. Applied and theoretical implications are discussed.  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