北京园林绿地6种树木的叶片和一年生枝中5种重金属含量比较

为了解不同园林树木对重金属的吸收情况,以北京市陶然亭公园、紫竹院公园、中科院植物园、马甸公园、皇城根遗址公园和营城建都滨水绿道不同环境绿地为样地,选择样地间共有的园林树木,采用ICP光谱仪测定了6种树木叶片和一年生枝条中重金属锌(Zn)、铬(Cr)、镍(Ni)、砷(As)和汞(Hg)的含量,以此为基础,采用隶属函数法将6种树木单位重量对5种重金属的综合富集能力进行排序,并对同树种叶片与当年生枝、5种重金属吸收量分别进行相关分析。结果表明：1)不同树种叶片和一年生生枝条单位重量中重金属含量有显著差异,且因重金属种类而异。Zn、As含量最高的为金银木,Cr、Ni、Hg含量最高的依次为圆柏、侧柏、丁香;丁香富集Zn、Cr、As的能力最低,白皮松富集Ni能力最低,侧柏富集Hg能力最低。2)树木叶片和当年生枝单位重量对5种重金属综合富集能力排序为：金银木＞侧柏＞圆柏＞油松＞丁香＞白皮松。其中,针叶树种中圆柏、侧柏、油松富集5种重金属的综合能力显著高于白皮松(P＜0.01),阔叶树种中金银木吸收重金属的能力显著高于丁香(P＜0.01)。3)树木不同器官中重金属含量也不同,不同树种间叶片与枝条中仅Cr含量具有显著相关性,相关系数为0.461(P＜0.01),其他4种元素均未达到显著水平。4)同树种叶片和当年生枝Cr和Ni吸收呈极显著相关性(P＜0.01),其他元素吸收之间未呈现相关性。本研究结果对北     

试析不当得利返还请求权与其他请求权的关系

不当得利请求权和民法上的其他请求权之间的关系问题，即是一个理论问题，也是一个实务问题，不仅涉及民法各项制度的功能体系，也事关不当得利返还请求权在处理民事案件中作用的发挥。以财产上的请求权发生的基础为核心，不当得利与合同、无因管理、物的返还、侵权行为等之间的关系的适用性，仍是实践中存在的突出问题。我们应承认不当得利返还请求权的独立性，并在此基础上承认它与其他财产上请求权可能发生的竞合，这样有助于民法各项制度的功能协调，有利于更加充分地实现民法维护公平正义这一根本理念。     

工作分享对促进工作—生活平衡的作用研究

本文在分析工作分享理论和实践的基础上,剖析了我国实施工作分享的现实需求,提出了中国实施工作分享对促进企业员工工作—生活平衡的理论设想,并进行了实证研究,验证了实施工作分享可以缓解工作—家庭冲突、促进工作—生活平衡,一定程度上降低工作压力。工作分享理论是“以人为本”的管理理论,有利于员工全面发展,实现员工从“经济人”向“社会人”,再向“自我实现人”的发展,有利于建设积极的员工与企业的协调关系。     

利益偿还请求权价值和性质探析

票据利益返还请求权作为票据法上一项特殊权利,在其性质方面争议颇多,我国学者普遍认为其是一种特别请求权。笔者认为特别请求权说并不能反映利益偿还请求权的本质,反而把该权利的性质变得更加深不可测。本文探讨了票据利益返还请求权的价值、性质,认为票据利益偿还请求权是一种不当得利请求权。     

毛泽东对马克思中间阶级理论的丰富与发展

毛泽东从中国革命及社会主义现代化建设的实际出发，对马克思的中间阶级理论进行了科学的理论诠释和实践诠释，形成了中国化的马克思主义中间阶级理论，对中国当前的小康社会建设和中国特色社会主义事业具有具有重大的理论指导意义。     

Work-Family Conflict: A Virtue Ethics Analysis

Work-family conflict has been examined quite often in human resources management and industrial/organizational psychology literature. Numerous statistics show that the magnitude of this employment issue will continue to grow. As employees attempt to balance work demands and family responsibilities, organizations will have to decide to what extent they will go to minimize this conflict. Research has identified numerous negative consequences of work-family stressors for organizations, for employees and for employees' families. There are however many options to reduce this strain, each with advantages and disadvantages. An ethical analysis, from a virtue ethics perspective, is applied to this timely issue to present an alternative view in addressing this critical business decision. In addition, a strong connection between the virtue ethics analysis and a well-known management theory is given to provide a foundation for managerial implications for resolving work-family conflict.     

Factors influencing women's decision to leave an organization following childbirth

The purpose of this study was to understand the reasons why college-educated women leave organizations after childbirth. Results from 228 women who participated in a study of intention to work following childbirth indicated specific work and family factors that differentiated mothers who returned to work from mothers who stayed home after childbirth. Comparisons were also made between women who had a child and those who anticipated having a child. The findings are discussed in terms of their implications for organizational policy makers.     

Can taking charge at work help hospitality frontline employees enrich their family life?

Managing work-family interface has been a key issue for hospitality employees. By integrating the literature on thriving at work into the work-family enrichment model, this study proposes taking charge as a resource-generating behavior that employees could undertake to enrich their family life. Using data collected on two occasions from frontline employees and their supervisors in a hotel in China, we find that those who take charge are more likely to experience thriving at work, which helps them improve the quality of their family life. Furthermore, working under a leader facing high role ambiguity augments this relationship. The study findings advance current work-family enrichment literature, and also carry important practical implications for promoting employees’ work-to-family enrichment in the hospitality sector.     

砂岩型铜矿成矿机制分析

近年来,我国各地发现大量的砂岩型铜矿,一时间出现了寻找砂岩型铜矿的热潮。本文通过分析云南省宁蒗县砂岩铜矿的地层、构造、岩浆活动、沉积环境、化学组成,探求其矿床成因,认为区内三叠系砂岩和砂页岩在还原环境下有利于铜矿富集,喜马期的岩浆及热液活动是矿进一步富集的重要因素。