Bio-inspired untethered fully soft robots in liquid actuated by induced energy gradients     

Liang Xiong Lyu  Fen Li  Kang Wu  Pan Deng  Seung Hee Jeong  Zhigang Wu  Han Ding 《国家科学评论(英文版)》2019,6(5):970

Soft robotics with new designs, fabrication technologies and control strategies inspired by nature have been totally changing our view on robotics. To fully exploit their potential in practical applications, untethered designs are preferred in implementation. However, hindered by the limited thermal/mechanical performance of soft materials, it has been always challenging for researchers to implement untethered solutions, which generally involve rigid forms of high energy-density power sources or high energy-density processes. A number of insects in nature, such as rove beetles, can gain a burst of kinetic energy from the induced surface-energy gradient on water to return to their familiar habitats, which is generally known as Marangoni propulsion. Inspired by such a behavior, we report the agile untethered mobility of a fully soft robot in liquid based on induced energy gradients and also develop corresponding fabrication and maneuvering strategies. The robot can reach a speed of 5.5 body lengths per second, which is 7-fold more than the best reported, 0.69 (body length per second), in the previous work on untethered soft robots in liquid by far. Further controlling the robots, we demonstrate a soft-robot swarm that can approach a target simultaneously to assure a hit with high accuracy. Without employing any high energy-density power sources or processes, our robot exhibits many attractive merits, such as quietness, no mechanical wear, no thermal fatigue, invisibility and ease of robot fabrication, which may potentially impact many fields in the future.  相似文献   

中国城市创新基础设施的时空特征及影响因素——基于291个地级及以上城市数据的实证分析     

于英杰  吕拉昌 《科技管理研究》2021,41(16):9-19

以中国291个地级及以上城市为研究对象,基于1995至2018年数据,以2010年为阶段分界点划分创新基础设施建设发展的演化阶段,从重大科技基础设施、科教基础设施、产业技术创新基础设施三方面,采用2010、2018年数据分析创新基础设施的空间分布特征,并构建线性回归模型、空间滞后模型和空间误差模型解析影响其分布的因素.结果表明:(1)中国创新基础设施建设在1995至2010年为初步发展阶段,2010年之后为快速增长阶段;(2)创新基础设施空间分布不均匀,符合胡焕庸线的分布规律,京津冀和长三角地区是东部核心区,其中重大科技基础设施空间分布整体呈"H"型,科教基础设施从北京为单核心演变到北京、上海双核突出,产业技术创新基础设施形成北京-天津、上海-杭州、广州-深圳的双核心共生结构;(3)创新基础设施空间分布具有一定集聚现象但集聚度较低,主要集中在京津冀、长三角及个别省份的发达城市;(4)总体上,财政政策和创新企业对创新基础设施影响最大,其次是创新人才和金融发展水平.由此提出未来中国城市创新基础设施发展要转变经济发展方式,加大政策支持、创新资金投入和扩大对外创新开放程度,营造活跃的创新环境以及完善创新机制等对策建议.  相似文献   

追寻“探索与利用”研究的发展轨迹及知识结构——基于文献计量研究     

刘林青  吕淑雅  梅诗晔 《现代情报》2018,38(3):150-158

探索性活动与利用性活动之间存在知识冲突与需求张力,如何从旨在长期获益的探索性活动和着眼于短期利益的利用性活动之间找寻平衡,是学术和管理实践迫切需要解决的难题。自1991年March提出探索与利用张力以来,相关研究迅速蔓延到组织的许多领域。本文以WOS中1991-2016年间"探索与利用"研究的施引文献为研究对象,从关键词共现、作品共被引、关键路径3个层次进行分析,挖掘该领域的研究热点,知识基础及关键路径,以期为学者提供文献分析的便利。基于上述分析发现,当今"双元性（Ambidexterity）"是该领域的热门研究主题,与"知识管理"、"动态能力"等研究紧密相连;本研究的样本文献从基础理论,"探索与利用"张力相关研究话题,研究方法论3个方面构建了该领域的知识基础;该领域研究存在着"探索与利用"张力的表现形式及解决办法两条关键发展路径,未发现转折点。  相似文献   

Internet policy in Korea: A preliminary framework for assigning moral and legal responsibility to agents in internet activities     

Hyeon-Suk Lyu 《Government Information Quarterly》2012

Although the internet has become increasingly pervasive in our daily lives and interactions and has impacted existing social norms and ethics, very few studies have examined the relationship between the internet and ethics. In the face of increasing numbers of internet-related ethical violations, this lack of research constitutes a policy vacuum. This study investigates ethical controversies in cyberspace by examining actual events that occurred in South Korea, such as the “dog poop girl” incident, the suicide of a famous actress, a candlelight vigil against U.S. beef imports, and the arrest of a blogger named “Minerva.” The study proposes a preliminary framework for evaluating ethical issues occurring on and via the internet, focusing on the agent's moral and legal responsibility and on internet regulation.  相似文献   

Development a case-based classifier for predicting highly cited papers     

Mingyang Wang  Guang Yu  Jianzhong Xu  Huixin He  Daren Yu  Shuang An 《Journal of Informetrics》2012,6(4):586-599

In this paper, we discussed the feasibility of early recognition of highly cited papers with citation prediction tools. Because there are some noises in papers’ citation behaviors, the soft fuzzy rough set (SFRS), which is well robust to noises, is introduced in constructing the case-based classifier (CBC) for highly cited papers. After careful design that included: (a) feature reduction by SFRS; (b) case selection by the combination use of SFRS and the concept of case coverage; (c) reasoning by two classification techniques of case coverage based prediction and case score based prediction, this study demonstrates that the highly cited papers could be predicted by objectively assessed factors. It shows that features included the research capabilities of the first author, the papers’ quality and the reputation of journal are the most relevant predictors for highly cited papers.  相似文献   

True directed forgetting in pigeons may occur only when alternative working memory is required on forget-cue trials     

Karen L. Roper  Daren H. Kaiser  Thomas R. Zentall 《Learning & behavior》1995,23(3):280-285

Results of directed-forgetting research with pigeons are difficult to interpret because of alternative nonmemorial accounts of performance decrements and important procedural differences from comparable research with humans. Prior research has noted the absence of directed forgetting when artifacts have been removed (e.g., nonreward following forget cues and differences in response patterns on remember and forget trials in training). In this article, it is argued that, in human directed-forgetting research, presentation of a forget cue allows for the reallocation of memory maintenance to items to be remembered. In the present experiment, true directed forgetting is found when nonmemorial performance decrements are eliminated and forget cues allow for the reallocation of sample memory to test-relevant cues.  相似文献   

Finding the diamond in the rough: Exploring communication and platform in crowdsourcing performance     

Kristen L. Guth  Daren C. Brabham 《Communication monographs》2017,84(4):510-533

Ideas that rise to the top in crowdsourcing platforms are assumed to succeed because they are perceived to be the best ideas, but questions about the factors that influence the outperformance of one solution over another remain underexplored. The Peer Vetted Ideas model is proposed as an explanation of elements that affect performance in crowdsourcing for creative ideation solutions. Using content analysis and hierarchical multiple regression, the study examined the relationship between performance in a public sector crowdsourcing competition and (a) design concepts, (b) communication about the designs, and (c) platform context. Results indicate that crowdsourcing is not always a meritocratic process to produce the objective “best” ideas, but rather also depends on subjective communicative, temporal, and platform factors.  相似文献   

有益于读者的资料索引工作     

满达人 《大学图书馆学报》1986,(1):28-29

<正> 早在五十年代初期,为配合教育革命和文学教学,我馆曾先后编辑了《高等教育资料索引》和《文艺资料索引》、后者已由甘肃人民出版社出版.在建国初期全国有关单位的资料索引工作很少开展的情况下,这两部"索引"在教学科研上曾发挥了一定作用.三十多年后的今天,特别是在粉碎"四人帮"后的六、七年来,我们又继续开展了有关资料索引的编辑工作.截止目前为止,包括建国初期编辑的两种索引在内,先后共编辑了各种专题索引(包括目录)19种,其中连续出刊的11种,总共8百余万字,4万余册,读者范围包括人专学校、机关、科研等单位以及各方面读者.共主要内容可分以下几个方面:  相似文献   

老年健身班在推动老年健身运动中的作用     

钟达人 《体育科学研究》1998,(3)

通过对复旦大学老年健身班的调查分析,探讨了老年健身班如何根据老年人的兴趣爱好和身体状况,组织和引导他们进行科学锻炼。  相似文献   

网络环境下吉林省农民信息素养提升研究     

詹晖  吕康银 《现代情报》2015,35(5):168-170

提高网络环境下农民的信息素养已成为吉林社会主义新农村建设存在的主要问题,本文通过对吉林省部分地区农民信息素养的调研,认为吉林省农民的信息素养有待提高,需要通过加强农业基础设施建设和强化农民信息教育、培训、完善信息服务体系来实现。  相似文献