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531.
滨河湿地地下水水位变化及其与河水响应关系研究   总被引:4,自引:0,他引:4  
滨河湿地的发育与退化过程受河流水文过程的显著影响.以黄河湿地国家自然保护区盂津湿地为研究对象,通过滨河湿地地下水位变化(特刖是小浪底水库调水调沙期间)野外定位观测,深入分析了滨河湿地地下水水位与洪水的响应关系.结果表明,滨河湿地地下水位受河水水位影响显著,地下水位的波动幅度与河岸距离之间存在明显的负指数关系,调水期内这...  相似文献   
532.
保护生态系统、提高居民福祉是实现联合国2030可持续发展目标的核心内容。在分析秦巴山区生态系统服务与居民福祉时空演化特征的基础上,采用弹性系数揭示了二者的时空耦合关系。研究发现:(1)1990—2018年秦巴山区水源涵养总量、土壤保持总量均呈波动下降趋势,碳储量总量则呈缓慢增长趋势,且各生态系统服务呈不同的空间分异特征。(2)1990—2018年居民福祉呈上升趋势,增幅高达220%,并呈“南高北低”的分布格局。(3)县域尺度上,三种生态系统服务与居民福祉明显不协调发展。其中,水源涵养、固碳服务与居民福祉的耦合关系均以“福祉增—服务减”为主,占比分别为88.75%、62.5%;而土壤保持服务与居民福祉的耦合关系则以“双增”为主,占比为57.5%。此外,各项生态系统服务与居民福祉反向变化区多分布于汉江河谷盆地和秦岭山脉中段。研究结果可为促进贫困山区生态系统服务与居民福祉协调发展提供决策依据。  相似文献   
533.
陕西省城市化与生态环境系统耦合关系   总被引:1,自引:0,他引:1  
采用层次分析法(AHP)和系统科学的理论构建了城市化与生态环境系统的评价指标体系和耦合模型,并将这个耦合系统的演化周期分为低级共生、协调发展等4个阶段,根据耦合度为45°时,耦合效果最佳的理论又可将协调发展阶段分为相对协调、最佳协调、低度协调3个状态.1990-2008年陕西省的城市化综合指数呈现直线上升的趋势,生态环...  相似文献   
534.
定量构效关系(Quantitative Structure Activity Relationship, QSAR)在化合物毒性虚拟计算领域被广为使用,能够高效、准确地用于化合物毒性的预测和风险评估.本文综述了利用QSAR方法开展化合物毒性预测中数据集、数据输入和模型方法3个领域的发展与变化,分析了研究的发展历程,提出了当前研究热点,并针对定量构效关系在化合物毒性预测领域的未来发展提出了展望.  相似文献   
535.
Although transformational leadership has been investigated in connection with change at higher levels of organizations, less is known about its “in‐the‐trenches” impact. We examined relations among transformational leadership, explicit change reactions (i.e., relationship quality), change frequency, and change consequences (i.e., task performance and organizational citizenship behavior (OCB)) during continuous incremental organizational change at lower hierarchical levels. In a sample of 251 employees and their 78 managers, analyses revealed that the quality of relationships between leaders and employees mediated the influence of transformational leadership on employee task performance and OCB. We also found that change frequency moderated the positive association of relationship quality with task performance and OCB, such that associations were stronger when change frequency was high. Copyright © 2012 John Wiley & Sons, Ltd.  相似文献   
536.
537.
Although the social exchange relationships between employers and employees are increasingly important to the performance of safety management systems, the psychological effects of work attitudes on this relationship have been less studied. Using a sample of first-line operators and their supervisors from 188 facilities in Taiwan which had Occupational Health and Safety Assessment Series 18000 (OHSAS 18000) certification, the current research conducted an empirical investigation of the influence of safety climate on organizational citizenship behavior (OCB). Work attitude was used to disclose the psychological effect. Research results indicated that (a) safety climate was a significant predicator of OCB, (b) the psychological effect significantly influenced social exchange relationships, and (c) job satisfaction showed a stronger mediating influence than organizational commitment due to the frequent top management turnover. Discussions and implications are also addressed.  相似文献   
538.
为有效提升煤矿企业安全管理效能,提高矿工安全绩效,基于资源保存理论、社会认知理论和自我决定理论,以团队层面的团队效能感和个体层面的安全动机为中介变量,探讨团队关系冲突(TRC)对矿工安全绩效的跨层次影响机制.对40个班组347名矿工进行问卷调查和实证研究,结果表明:TRC不仅能直接负向影响矿工安全绩效,还能通过团队效能...  相似文献   
539.
Aron Ralston and Christopher McCandless, two outdoor adventurers, have captured the hearts of many American environmentalists. Each has attained the status of cultural icons and inspired books and films to recount their tales. While entertainment media have romanticized both individuals, news media are not as easy on one—McCandless is vilified while Ralston is valorized. When reporting these stories, news media outlets attempted to retell each story in a way that conforms to the dominant American ideology of wilderness, where “progress” is marked by control over nature—control that both Ralston and McCandless clearly unsettled. In addition, both committed many of the same errors in being underprepared. Despite these similarities, why are they each presented so differently in the news media? This paper offers a rhetorical analysis of newspaper articles on each story, where the phenomenon of scapegoating alienates McCandless, and the phenomenon of mortification purifies Ralston, restabilizing this American environmental ideology in both stories. In conclusion, I argue that the essential difference between these two stories is that they present two opposing ideals of a human–nature relationship, with Ralston's ideology including a space for technology and industrial knowledge, and thus construed as more appropriate than McCandless' ideology.  相似文献   
540.
Employee engagement has recently been introduced as a concept advantageous to organizations. However, little is known about the value of employee engagement in explaining work performance behaviors compared with similar concepts. The learning climate, defined as the organization's beneficial activities in helping employees create, acquire, and transfer knowledge, has also been proposed as an antecedent of employee engagement. Using data from a sample of 625 employees and their supervisors in various occupations and organizations throughout Israel, we investigated employee engagement as a key mechanism for explaining the relationship between perceptions of the organization's learning climate and employees' proactivity, knowledge sharing, creativity, and adaptivity. We also tested whether employee engagement explained the relationship more thoroughly than similar concepts such as job satisfaction and job involvement. Multilevel regression analyses supported our hypotheses that employee engagement mediates the relationship between the perceived learning climate and these extra‐role behaviors. Moreover, engagement provides a more thorough explanation than job satisfaction or job involvement for these relationships. The implications for organizational theory, research, and practice are discussed. Copyright © 2015 John Wiley & Sons, Ltd.  相似文献   
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