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   61篇
  免费   10篇
  国内免费   17篇
安全科学   32篇
环保管理   10篇
综合类   14篇
基础理论   24篇
污染及防治   2篇
社会与环境   4篇
灾害及防治   2篇
  2023年   1篇
  2022年   2篇
  2021年   3篇
  2020年   7篇
  2019年   6篇
  2018年   3篇
  2017年   7篇
  2016年   8篇
  2015年   7篇
  2014年   5篇
  2013年   4篇
  2012年   7篇
  2011年   3篇
  2010年   8篇
  2009年   3篇
  2008年   4篇
  2007年   1篇
  2006年   1篇
  2005年   2篇
  2003年   1篇
  2001年   1篇
  2000年   1篇
  1999年   1篇
  1977年   1篇
  1971年   1篇
排序方式: 共有88条查询结果,搜索用时 15 毫秒
41.
Since the last few decades, terrestrial diversity is found to be under stress due to the contamination by various chemicals and gases of aquatic and agricultural media. The bioaccumulation of these compounds at certain concentrations in different tissues produces histopathological changes leading to behavioral changes in target animals. This study focused on terrestrial molluscan slug, Semperula maculata, against lethal concentrations of mercury chloride (HgCl2). Bioaccumulation of Hg was highest in ovotestis, while lowest in the molluscan penis. Histopathological changes were observed in the cellular arrangement of reproductive organs. Alterations in the penis and the dart gland included dilated unicellular, multicellular glands, and muscular dystrophy, dilated peripheral glandular cells, respectively; dilation being maximal in the prostate gland. Ovotestis showed depleted number of gametocytes. Vacoulized pre-vitellogenic oocytes with early vitellogenic oocytes were noted under light microscopy. Mercury produced toxicity on secretory functions and lowered the rate of reproduction in animals. Evidence indicates that Hg produced gamete degeneration, impacted reproductive capacity and survival of this species in the ecosystem.  相似文献   
42.
采用生物行为传感器获取青鳉鱼的行为数据时,青鳉鱼个体差异会导致采集到的原始电信号在时空特性下完全不同。重要的行为特征往往被隐藏在原始信号中,传统的信号处理方法无法实时而有效地提取到这些特征。针对这个问题,观察并记录了暴露实验前后青鳉鱼的行为变化,提出了一种可以高效表征行为特征的直方图统计算法。实验结果表明,该方法能够准确对应人眼观测到的暴露实验前后鱼的行为变化趋势,同时也为后续异常行为识别提供一定的支持和参考。  相似文献   
43.
在人本主义地理学框架下,对城市社会空间结构的分类研究成为必然。以流动人口空间结构为主题,总结了城市化一空间的二元分析框架。在此基础上重点构建了流动人口空间结构体系,对流动人口区位空间、行为空间和感应空间的涵义、特征、功能等进行解析。认为流动人口空间是在城市空间基底上叠加的具有流动人口特质的空间形态,是一种再造的空间。提出流动人口收入水平及行为活动的多少是影响流动人口空间关系的主要因素。  相似文献   
44.
为预防和控制新生代员工不安全行为的出现,探讨心理资本、犬儒主义与工作场所不安全行为之间的关系,并以行为实验方式检验心理资本干预的有效性。基于构建的假设理论框架,通过行为实验对心理资本开发干预在增加心理资本、减少犬儒主义和不安全行为方面的有效性进行测试。结果表明:心理资本与不安全行为负相关;犬儒主义与不安全行为正相关;心理资本与犬儒主义负相关。心理资本干预措施效果良好,能够直接减少犬儒主义,间接降低不安全行为出现概率,支持心理资本干预的有效性,多组中介模型分析支持假设提出的犬儒主义中介作用。研究结论为提升新生代员工安全管理水平,深化心理资本和犬儒主义领域的理论与实践研究提供参考和借鉴。  相似文献   
45.
久效磷(MCP)是一种广谱类内吸附性有机磷农药和潜在的神经毒剂,能够对非靶生物产生神经毒性作用,而行为毒性是神经毒性的主要表现形式. 以运动、学习与觅食行为、乙酰胆碱酯酶活性为指标,研究了久效磷对非靶生物——秀丽隐杆线虫(Caenorhabditis elegans,下称线虫)行为的影响. 结果显示:经0.5、5.0和50.0 mg/L久效磷暴露后,各暴露组线虫头部摆动和身体弯曲频率均极显著降低,0.5 mg/L暴露组线虫向前摆动频率显著减少,5.0和50.0 mg/L暴露组线虫向前摆动频率极显著减少;5.0和50.0 mg/L暴露组线虫在NaCl存在和缺少食物条件下,对NaCl的趋向性极显著升高;与对照组相比,50.0 mg/L暴露组线虫菌落接触率在2、4、6、8 h时均显著降低,在24 h时极显著降低;各暴露组线虫的乙酰胆碱酯酶活性均受到极显著抑制. 表明久效磷能够导致线虫运动、学习与觅食行为的严重缺陷,乙酰胆碱酯酶活性抑制与久效磷对线虫运动行为的影响呈正相关,与其学习行为的影响呈负相关.   相似文献   
46.
基于SEM的不安全行为与其意向关系的研究   总被引:4,自引:2,他引:2  
为检验不安全行为与不安全行为意向的关系,基于计划行为理论(TPB),对7个煤矿的735名一线作业人员进行问卷调查,收集工人被记录的和未被记录的不安全行为数据。采用结构方程模型(SEM)对不安全行为意向与不安全行为之间的关系进行分析。结果表明:安全行为态度、班组安全氛围、不安全行为风险认知偏差与不安全行为意向显著相关(路径系数分别为-0.36,-0.23和-0.57);不安全行为意向与不安全行为显著相关(路径系数为0.85);行为风险认知偏差与不安全行为显著相关(路径系数为0.51);而安全行为态度、班组安全氛围与不安全行为的关系并不显著。  相似文献   
47.
行人违章过街行为心理成因分析及预测   总被引:2,自引:2,他引:0  
为深入了解行人在交叉口违章过街行为,调查影响行人在长周期信号控制交叉口违章过街的心理成因,采用计划行为理论(TPB)制作了行人违章过街心理行为问卷。利用此问卷,对上海居民进行过街违章心理研究,得到250个覆盖各年龄层的有效样本。信度效度分析验证了行人违章过街心理行为问卷能够用来解析行人的违章过街心理成因。在对问卷中自述违章过街行为和心理要素的聚类分析筛除明显隐瞒自身违章过街行为的行人后,对心理要素和现实行为违章行为进行判别分析。结果表明:问卷中2个TPB的心理要素:知觉行为控制和行为意向能够用来推测行人的实际违章行为,准确率为73.9%。其中,代表行人对交叉口交通情况和自身时间约束的心理要素知觉行为控制对行人违章行为有关键的影响。  相似文献   
48.
The ability of both regulators and farmers themselves to monitor the impact of environmental practices may be an issue with nonpoint source pollution. Effects that can be perceived via direct sensory evidence provide information at low cost. Results from a survey of livestock farmers suggest that a practice that has more obvious effects on water quality, manure application setbacks, is more likely to be adopted than a more complicated one with less visible effects, manure testing. Farmers’ perceptions of the profitability of the two practices were similar. The importance of observability and complexity has implications for educational programs.  相似文献   
49.
Dispersal propensity, reflecting one of the most decisive mammalian life history traits, has been suggested to vary heritably and to locally adapt to prevailing dispersal conditions in wild house mouse populations. Because individual dispersal propensity highly significantly covaries with the developmental timing of the onset of agonistic interactions between littermate brothers, we used agonistic onset as an endophenotype to explore the potential genetic basis of dispersal-related behavioral variation in male house mice. We found significant covariation of microsatellite marker compositions with the probability of fraternal pairs to exhibit agonistic relationships before the age of 2 months. In particular, the presence of two alleles associated with a serotonin transporter protein gene (Slc6a4) and a testosterone dehydrogenase gene (Cyp3a11), respectively, strongly covaried with the probability of early agonistic onset. These results are congruent with recent findings of microsatellite length polymorphisms marking regulatory variation of gene expression that is relevant for social behavior, including dispersal propensity development, in other mammals. Genetic variability for ontogenetic timing of agonistic onset would be in agreement with genotypic differentiation of the dispersive behavioral syndrome in natural populations that could lead to local adaptation.  相似文献   
50.
Abstract: The last century has seen the ascendance of a core economic model, which we will refer to as Walrasian economics. This model is driven by the psychological assumptions that humans act only in a self‐referential and narrowly rational way and that production can be described as a self‐contained circular flow between firms and households. These assumptions have critical implications for the way economics is used to inform conservation biology. Yet the Walrasian model is inconsistent with a large body of empirical evidence about actual human behavior, and it violates a number of basic physical laws. Research in behavioral science and neuroscience shows that humans are uniquely social animals and not self‐centered rational economic beings. Economic production is subject to physical laws including the laws of thermodynamics and mass balance. In addition, some contemporary economic theory, spurred by exciting new research in human behavior and a wealth of data about the negative global impact of the human economy on natural systems, is moving toward a world view that places consumption and production squarely in its behavioral and biophysical context. We argue that abandoning the straightjacket of the Walrasian core is essential to further progress in understanding the complex, coupled interactions between the human economy and the natural world. We call for a new framework for economic theory and policy that is consistent with observed human behavior, recognizes the complex and frequently irreversible interaction between human and natural systems, and directly confronts the cumulative negative effects of the human economy on the Earth's life support systems. Biophysical economics and ecological economics are two emerging economic frameworks in this movement.  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