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   154篇
  免费   21篇
  国内免费   8篇
安全科学   58篇
环保管理   32篇
综合类   31篇
基础理论   20篇
环境理论   2篇
污染及防治   1篇
评价与监测   2篇
社会与环境   26篇
灾害及防治   11篇
  2024年   3篇
  2023年   1篇
  2022年   6篇
  2021年   7篇
  2020年   10篇
  2019年   11篇
  2018年   10篇
  2017年   21篇
  2016年   16篇
  2015年   6篇
  2014年   11篇
  2013年   12篇
  2012年   7篇
  2011年   11篇
  2010年   9篇
  2009年   5篇
  2008年   6篇
  2007年   3篇
  2006年   7篇
  2005年   1篇
  2004年   2篇
  2003年   3篇
  2002年   3篇
  2001年   1篇
  2000年   3篇
  1999年   1篇
  1996年   2篇
  1994年   1篇
  1993年   1篇
  1990年   1篇
  1985年   1篇
  1978年   1篇
排序方式: 共有183条查询结果,搜索用时 31 毫秒
61.
早期结瘤素93(ENOD93)蛋白在植物根瘤形成初期扮演着重要的角色.基于大麦基因组信息鉴定大麦ENOD93基因家族成员,分析其理化特性、进化关系、基因结构、蛋白质结构和启动子顺式作用元件;并分析ENOD93家族在不同组织和不同基因型(籽粒大小)的表达情况.结果显示,大麦ENOD93基因家族有16个成员,均含有ENOD93基因家族特有的保守结构域;编码区长度在207-627 bp之间,外显子数量有1-4个,平均2.75个,且大部分位于细胞膜上;进化树结果表明与水稻、小麦和玉米等禾本科植物ENOD93基因的亲缘关系较近;启动子顺式元件主要有植物生长发育响应元件、胁迫响应元件以及激素响应元件;大部分HvENOD93基因在灌浆期籽粒和大粒材料中表达量较高.推测大麦HvENOD93基因在籽粒大小形成中起关键性作用;另外,结合其他物种相关基因研究结果,共筛选出3个同源基因.(图4表2参45)  相似文献   
62.
ABSTRACT

The concept of reflexive governance has to a large extent emerged from an increasing recognition of the need to consider different meanings of nature in the environmental policy-making process. Yet, so far, little attention has been paid to creating conditions for reflexive governance among different actors in intercultural settings, particularly in the context of environmental conflict and strong cultural change among indigenous peoples. This paper reviews three participatory research projects carried out in the Gran Sabana in Canaima National Park, Venezuela, which facilitated dialogue among indigenous people regarding their conflicting views of fire, in part by developing community-wide critical reflections on processes of cultural change and identity formations. These experiences suggest that once marginalized environmental knowledge is publicly acknowledged within the context of endogenous cultural processes, indigenous people feel more confident to engage in dialogue with other actors, thus allowing the emergence of reflexive environmental governance.  相似文献   
63.
为了解人类近亲恒河猴piwil1基因的结构、表达和功能差异,利用RT-PCR方法克隆了恒河猴piwil1基因,并对其编码产物进行了相应的生物信息学分析,随后检测了piwil1 mRNA在成年恒河猴10种组织中的表达情况,最后利用免疫组化方法比较了PIWIL1蛋白在成人、成年恒河猴和幼年恒河猴睾丸组织中表达的异同.结果表明,恒河猴piwil1基因全长2 586 bp,编码861个氨基酸,氨基酸数目与人类piwil1基因相同.恒河猴PIWIL1蛋白与人的PIWIL1蛋白序列同源性达99%,均含有PAZ结构域和Piwi结构域.在成人和成年恒河猴的睾丸组织中,PIWIL1蛋白均在精母细胞和精细胞的胞浆中表达,而在幼年恒河猴睾丸组织中,PIWIL1表达与成年恒河猴相比存在差异,表达量相对较低,且主要表达于生精小管的细胞的细胞核上.上述结果提示,PIWIL1蛋白在成人和成年恒河猴可能具有相同作用,但是在不同的发育阶段中PIWIL1蛋白的功能不同.  相似文献   
64.
Although the prevalence of employees working within the same workplace or occupation with their spouse has increased, relatively little research has examined their experiences. On the basis of the boundary and conservation of resources (COR) theories, we argue that higher levels of work–family role integration among work‐linked couples will lead to higher levels of spousal support resources and lower levels of work–family conflict. This will, in turn, lead to lower emotional exhaustion among employees in a work‐linked relationship. Among two samples of employees in a variety of occupations, we found that being in a work‐linked relationship was associated with both higher spousal instrumental support as well as different forms of work–family conflict. The interaction between spousal support and work–family conflict was associated with emotional exhaustion. We discuss the implications of these findings for boundary and COR theories in terms of movement of resources across work–family boundaries and resource relevance in the strain process. Copyright © 2011 John Wiley & Sons, Ltd.  相似文献   
65.
This paper examines what organizations and groups individuals rely on to help prepare for natural disasters and how reliance differs vis-à-vis demographic characteristics. Using data gathered from 2,008 individuals employed in the United States, the results revealed that individuals are significantly more likely to rely on friends and family than government organizations at the local, state, and federal level. The findings also suggest that this reliance varies across demographic groups. For example, data from the present study suggest that women and minority groups as well as individuals who are older and less educated are significantly more likely to rely on organizations to help prepare for natural disasters. This study contributes to the disaster management and risk communication literatures by offering key insights into the organizations and groups the American public in general, and certain demographic groups in particular, rely on when it comes to preparing for natural disasters. Knowledge about the organizations and groups that individuals rely on to help prepare for natural disasters can help policymakers and practitioners target those organizations as conduits to deliver critical preparedness information, as well as other information related to disaster mitigation, response, and recovery.  相似文献   
66.
Retirement transition has become a prolonged process of adaptation, including changes in role identity. However, there is a dearth of research on the process by which retirees cope with the role transition, including how pre-retirement role identities shape the transition, the forms of identity work undertaken by retirees, and the unfolding nature of retirement transition. In an in-depth qualitative examination of the transition process, we identify pre-retirement role identity profiles based on work and nonwork role identities. We then examine how pre-retirement role identities influence the transition process, including the nature of identity work in transition and the transition pathways demonstrated by retirees. Our findings provide insights into strengths and limitations afforded by pre-retirement identities: They facilitate agentic coping in which retirees shed old and adopt new identities but also impose inertia and prolong the transition until identity crises force the retirees to undergo identity exploration and adoption of new identities.  相似文献   
67.
Introduction: Despite the rich tradition of research on predictors of workplace injury, most studies rely on cross-sectional, between-person designs. Furthermore, prior research has often overlooked the possibility that factors outside the work domain can influence the occurrence of actual injuries at work. To address these limitations, the current study examined the effects of work and family demands on the occurrence of workplace injury. Drawing on the intuition of the work-home resources model (W-HR), we investigated how within-person level changes in demands and resources from both domains influence work injuries over a 12-year period. Method: We used 12 years of longitudinal data (N = 7,820) to study the long-term within-person changes in work and family domains and to capture the event of low frequency incidence such as workplace injury. Specifically, we conducted multilevel analyses to study the links between within-person change in time and energy resources both in work and family domains and within-person change in the likelihood of experiencing a workplace injury. Results and conclusion: The findings showed that within-person changes in work hours, spousal work hours, income and number of children, were significantly associated with changes in the likelihood of experiencing a workplace injury. We conclude with a discussion of implications for theory and future research of workplace injuries. Practical application: The research provided useful insights on the intimate association between work and family domains in the context of safety management.  相似文献   
68.
Place attachment has been researched extensively in the social and behavioural sciences over the past two decades. However, it is challenging for researchers to assimilate the mixed messages presented in the place attachment literature and to understand the multiple place attachment terms. In this study, a four-dimensional model of rural landholder attachments to their natural resource management region was conceptually and empirically developed with the aim of developing an integrated approach to the measurement of place attachment that clearly distinguishes between different elements of place scholarship. A 29-item place attachment scale with the dimensions of place identity, place dependence, nature bonding, and social bonding was tested on a random sample of rural landholders in the Adelaide and Mount Lofty Ranges in South Australia (N = 320). The majority of respondents were male (69.3%) and the average age was 59 years. The scale was reduced to 20-items and then administered simultaneously and in the same response format to rural landholders in two other areas of South Australia: the Northern and Yorke region (N = 664) and South Australian Murray-Darling Basin region (N = 659). In both studies, the majority of respondents were male (85%) and the average age was 55 years. Exploratory factor and reliability analyses of Adelaide and Mount Lofty Ranges and Northern and Yorke datasets produced a five-dimensional model of place attachment with high reliabilities. Social bonding divided into the constructs of family bonding and friend bonding. The refined five-dimensional model was then examined for convergent validity, with moderate but significant correlations found between individual attachment constructs and dependent variables expected to be related to the construct, such as place identity and length of residence, and nature bonding and time currently spent in nature. We used confirmatory factor analysis to test the goodness-of-fit of the South Australian Murray-Darling Basin (SAMDB) dataset to the proposed five-dimensional model and then compared its fit to the traditional two-dimensional model of place identity and place dependence. The five-dimensional model provided moderate fit for the SAMDB data. We conclude with a discussion of the validity and reliability of the five-dimensional model and its future role in place attachment research.  相似文献   
69.
ABSTRACT

Although recent expansions in hydraulic fracking operations across the United States have led to greater news coverage and attention from the public, overall understanding remains fairly low. For some, relevant social identities, including environmental or political, may provide a short cut to becoming informed about fracking, or to determining what they believe about it and how that influences their positions on fracking policies. Social identity influence frameworks provide an approach to understanding the relationships between belief and identity, which this study investigates through its affiliational and attitudinal components. National survey data are used to model pathways from environmental and political identities to beliefs about risks associated with fracking. Environmental attitudes significantly predicted belief that fracking has health risks, and mediated a relationship from environmental group affiliation, but environmental information was not significant. Ideology had direct and indirect effects, through partisan media use, while partisanship had direct effects on beliefs about environmental risks.  相似文献   
70.
三峡库区城镇移民家庭生活安置状况调查与分析   总被引:1,自引:0,他引:1  
利用回溯性的调查资料来研究已经搬迁的城镇移民家庭在搬迁后的生活安置现状,分析城镇移民家庭的生活安置适应性。在评价方法上首先是对比城镇移民家庭搬迁前后的生活条件和社会保障的变化,再分析移民各个分项满意程度,最后将所提取的因子得分值作为自变量,总体“生活安置满意度”作为因变量,对数据进行Logistic回归分析,分析移民安置过程中哪些方面的满意度会影响到城镇移民对总体安置满意度的判断。研究发现城镇移民家庭的生活居住条件良好。搬迁后,城镇移民家庭的生活和居住条件都得到了较大幅度的改善,住房面积增大,房屋居住的安全系数有所提高。城镇移民家庭医疗保险享有率很高,但养老保险的享有率不容乐观,城镇移民家庭的养老保障仍有待提高。城镇移民生活安置满意度随着社区满意度和居住满意度的提高而提高  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