战略性关键矿产资源供给安全研究综述与展望     

吴巧生  周娜  成金华 《资源科学》2020,42(8):1439-1451

战略性关键矿产资源事关人类社会持续发展、在关键领域发挥战略性作用。本文从战略性关键矿产资源的界定与遴选、供给风险评价与预警、供给安全体系优化与政策三方面对当前研究进行了综述。主要结论有：①战略性关键矿产资源是满足国防军事需求与实现战略性关键产业良性发展的原材料,是一个国家或地区主权属性的集中体现,需结合国家或地区发展实际动态遴选战略性关键矿种;②战略性关键矿产资源供给风险具有更强的模糊性与不确定性,战略性关键矿产资源供给风险评价模型的建立面临诸多挑战;③通过全球资源优化配置,完善全球治理体系,是战略性关键矿产资源供给安全体系优化与政策选择的重要方向。从多学科交叉研究供给安全的形成机理,由大数据驱动与全球供给链跟踪明确供给风险评价要素,基于外部冲击因素和内部产业因素结合的视角完善战略性关键矿产资源供给安全政策是未来战略性关键矿产供给安全研究的重要方向。  相似文献   

黄河流域农村饮水安全问题及对策     

袁星  孔畅  王利  韦炳干  李海蓉  杨林生 《资源科学》2020,42(1):69-77

21世纪以来中国农村饮水安全工程建设取得重大成就,截至2018年底,全国农村自来水普及率已达到80%以上,解决了绝大多数农村人口的安全饮水问题。然而黄河流域部分农村地区水资源短缺、水源水质差、饮水型地方病危害重、饮用水水源地缺乏保护和农村饮水安全工程不完善等问题突出,饮水安全保障工作相对于全国农村饮水安全工程进程较为滞后。为切实解决黄河流域农村人民群众的饮水安全问题,促进黄河流域生态保护和高质量发展,本文综述了目前黄河流域饮水安全突出的问题,并结合全国农村饮水提质增效的工作目标,提出了进一步做好流域内农村饮水安全工作的建议,包括实现水资源动态配置、加强饮水安全设施建设和工程管理、强化水源地保护与监测等,从优先保障饮用水水量和水质方面全面维护流域内农村地区的饮水安全。  相似文献   

在线评论对异质性消费者购买决策的影响研究——基于眼动实验          下载免费PDF全文

唐晓莉  宋之杰 《情报科学》2020,38(4):83-88

【目的/意义】本研究基于个体认知加工的视角,探索消费者对在线评论有用性的感知过程和感知结果,并揭示在线评论影响消费者购买决策的过程机制。【方法/过程】本研究以120名大学生为被试,开展2评论类型(客观VS主观)×2认知需求(高VS低)的眼动实验,探索消费者对于在线评论有用性的感知过程和感知结果。【结果/结论】结果表明:(1)与主观体验评论相比,消费者对客观属性评论的注视时间更长,感知有用性更大,购买意愿也更强;(2)与高认知需求者相比,低认知需求者的注视时间较短,感知有用性较大,购买意愿也较大;(3)认知需求显著调节评论类型对注视时间的影响,但对感知有用性和购买意愿的调节效应不显著。据此,建议相关企业采取个性化匹配的措施,使得评论类型能够切合消费者的认知需求水平,以便提高在线评论的感知有用性和消费者的购买意愿,从而做出更为满意的购物决策。  相似文献   

Internet‐based Science Learning: A review of journal publications     

Silvia Wen‐Yu Lee  Ying‐Tien Wu  Meng‐Jung Tsai  Tzu‐Chien Liu  Fu‐Kwun Hwang 《International Journal of Science Education》2013,35(14):1893-1925

Internet‐based science learning has been advocated by many science educators for more than a decade. This review examines relevant research on this topic. Sixty‐five papers are included in the review. The review consists of the following two major categories: (1) the role of demographics and learners' characteristics in Internet‐based science learning, such as demographic background, prior knowledge, and self‐efficacy; and (2) the learning outcomes derived from Internet‐based science learning, such as attitude, motivation, conceptual understanding, and conceptual change. Some important conclusions are drawn from the review. For example, Internet‐based science learning is equally favorable, or in some cases more so, to learning for female students compared to male students. The learner's control is essential for enhancing students' attitudes and motivation toward learning in Internet‐based science learning environments. Nevertheless, appropriate guidance from teachers, moderators, or the Internet‐based learning environment itself is still quite crucial in Internet‐based science learning. Recommendations for future research related to the effects of Internet‐based science learning on students' metacognitive reflections, epistemological development, and worldviews are suggested.  相似文献   

The influence of academic self-efficacy on academic performance: A systematic review     

《Educational Research Review》2016

This review integrates 12 years of research on the relationship between academic self-efficacy and university student's academic performance, and known cognitive and motivational variables that explain this relationship. Previous reviews report moderate correlations between these variables, but few discuss mediating and moderating factors that impact this relationship. Systematic searches were conducted in April 2015 of psychological, educational, and relevant online databases for studies investigating academic self-efficacy and performance in university populations published between September 2003 and April 2015. Fifty-nine papers were eligible. Academic self-efficacy moderately correlated with academic performance. Several mediating and moderating factors were identified, including effort regulation, deep processing strategies and goal orientations. Given the paucity of longitudinal studies identified in this review, further research into how these variables relate over time is necessary in order to establish causality and uncover the complex interaction between academic self-efficacy, performance, and motivational and cognitive variables that impact it.  相似文献   

中国企业跨国并购的国家安全审查:以美国为例     

刘凤朝  姜滨滨 《科学学与科学技术管理》2010,31(3)

金融危机的爆发使一些处于技术前沿或领先地位的国外企业陷入困境,为中国企业走出国门进行跨国并购提供了契机.以美国为例,研究其针对外资并购的国家安全审查,重点分析国家安全审查的程序及范围,结合外国投资委员会最新年报阐明近年来外国企业并购美国企业的趋势,并对中国企业并购美国企业提出相关建议.  相似文献   

成人教育与学习参与障碍研究述评与展望     

陈国华 《职教通讯》2012,(22):42-46

通过整理近年来国内外的相关文献,对当前成人教育与学习参与障碍的研究成果进行系统的总结与归纳。重点对成人教育与学习参与障碍的内涵、情境障碍、机构障碍、心理障碍与信息障碍进行梳理,最后从成人教育与学习参与障碍未来本土化理论体系的建构与多元化研究方法的采用方面进行展望。  相似文献   

The impact of peer achievement and peer heterogeneity on own achievement growth: Evidence from school transitions     

《Economics of Education Review》2013

This paper estimates ability peer effects on achievement growth in reading and math. It exploits variation in peer characteristics generated at the transition from primary to secondary school in a sample of Berlin fifth-graders. As will be discussed in detail, this variation is exogenous in large parts. Results are similar for both achievement measures: pupils benefit from abler peers, but high-achievers do so to a smaller extent. The variance in peer skills has no impact on achievement growth – the corresponding estimates are negative, but insignificant.  相似文献   

对现阶段我国普通高校体育教学模式的审视与思考   总被引：1，自引：1，他引：0  

李剑  杨继星 《体育科技文献通报》2010,18(1):58-60

探讨现阶段我国普通高校体育教学模式,会更有利于树立和正确理解＂健康第一＂的指导思想,发挥出体育课程应有的作用与价值。本文运用系统论的观点,对构成体育教学过程的因素进行分析,从整体的角度探讨普通高校体育教学模式,为我国普通高校体育教学提供相应的参考。  相似文献   

新中国农村经营体制改革60年回顾与展望     

关锐捷  禤燕庆 《科技成果管理与研究》2010,(1):83-86

本文回顾了共和国60年来农村经营体制随着国家经济体制变化而发生的重大变革，以及呈现出的鲜明时代特点。通过分析农村经营管理体制变迁史，总结吸取其中成功的经验和失败的教训，以便更好的推动中国农村经管事业健康发展。针对随着社会经济发展，如何解决农业经营体制机制方面的深层次矛盾也进行了展望和论述。  相似文献