Four pitfalls in normalizing citation indicators: An investigation of ESI’s selection of highly cited papers     

Zhigang Hu  Wencan Tian  Shenmeng Xu  Chunbo Zhang  Xianwen Wang 《Journal of Informetrics》2018,12(4):1133-1145

InCites Essential Science Indicators is becoming increasingly used to identify top-performing research and evaluate the impact of institutes. Unfortunately, our study shows that ESI indicators, as well as other normalized citation indicators, have the following flaws. First, the publication month and the online-to-print delay affect a paper’s probability of becoming a Highly Cited Paper (HCP). Papers published in the earlier months of the year are more likely to accumulate enough citation counts to rank at the top 1% compared with those published in later months of the year. Papers with longer online-to-print delays have an apparent advantage for being selected as HCPs. Research field normalizations lead to the third pitfall. Different research fields have different citation thresholds for HCPs, making research field classification important for a journal. In addition, the uniform thresholds for both articles and reviews in ESI affect the reliability of HCP selection because, on average, reviews tend to have higher citation rates than articles. ESI’s selection of HCPs provides an intuitive feel for the problems of normalized citation impact indicators, such as those provided in InCites and SciVal.  相似文献   

Specific tackling situations affect the biomechanical demands experienced by rugby union players     

Elena Seminati  Dario Cazzola  Ezio Preatoni  Grant Trewartha 《Sports biomechanics / International Society of Biomechanics in Sports》2017,16(1):58-75

Tackling in Rugby Union is an open skill which can involve high-speed collisions and is the match event associated with the greatest proportion of injuries. This study aimed to analyse the biomechanics of rugby tackling under three conditions: from a stationary position, with dominant and non-dominant shoulder, and moving forward, with dominant shoulder. A specially devised contact simulator, a 50-kg punch bag instrumented with pressure sensors, was translated towards the tackler (n = 15) to evaluate the effect of laterality and tackling approach on the external loads absorbed by the tackler, on head and trunk motion, and on trunk muscle activities. Peak impact force was substantially higher in the stationary dominant (2.84 ± 0.74 kN) than in the stationary non-dominant condition (2.44 ± 0.64 kN), but lower than in the moving condition (3.40 ± 0.86 kN). Muscle activation started on average 300 ms before impact, with higher activation for impact-side trapezius and non-impact-side erector spinae and gluteus maximus muscles. Players’ technique for non-dominant-side tackles was less compliant with current coaching recommendations in terms of cervical motion (more neck flexion and lateral bending in the stationary non-dominant condition) and players could benefit from specific coaching focus on non-dominant-side tackles.  相似文献   

纳米流体液滴撞击固体壁面的实验和模拟研究     

王睿  沈学峰  霍元平  王军锋  郑诺  刘海龙 《中国科学院大学学报》2020,37(2):281-287

液滴撞击固体壁面现象常见于动力机械、喷雾冷却和薄膜材料沉积制备等工业生产中。将石墨烯和碳纳米管作为分散颗粒，应用超声波分散技术制备均匀性与稳定性良好的树脂基纳米流体。利用高速摄像技术，研究纳米流体液滴撞击固体壁面的动力学行为。基于有限元法，通过修正的幂律黏度模型耦合纳米流体的剪切变稀特性，采用水平集方法捕捉相界面的移动，建立纳米流体液滴撞击固体壁面的数值模型。模拟结果与实验结果较好一致，验证了数值模型的正确性与准确性。研究发现实验配制的纳米流体表现出非牛顿剪切变稀特性，纳米颗粒的加入抑制了液滴撞击固体壁面过程中的铺展和回缩行为。随着幂律指数m的减小，液滴撞击固体壁面后的铺展范围变大。随着表面张力的增大，液滴的无量纲直径在铺展阶段无明显变化，但在回缩阶段逐渐减小。  相似文献   

新冠肺炎后演艺行业的走势     

姚石 《演艺科技》2020,(3):1-3

2020年,演艺行业虽受新冠肺炎疫情影响,但需求始终存在,并能够随着经济的增长而增长。5G、大数据中心、人工智能和工业互联的发展,将推动演艺行业在在线化、专业音视频与消费类产品融合发展。  相似文献   

比较文学教学的四个关键词     

吴家荣 《安徽教育学院学报》2011,29(1):116-118

比较文学作为一门学科,内容丰富、学理性强。如何使学生真正了解比较文学学科的价值、意义,使他们正确运用比较文学原理、方法,深入开展文学研究,四个关键词至关重要,即：比较;影响;可比性;变异性。学生只有充分了解关键词的含义,切实掌握了关键词的运用,比较文学的教学才能收到事半功倍的成效。  相似文献   

Evaluating indicator‐based methods of ‘measuring long‐term impacts of a science center on its community’     

Eric Allen Jensen 《科学教学研究杂志》2016,53(1):60-64

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我国大学生体育态度对自我和谐的影响研究*     

顾春先 《广州体育学院学报》2016,(5):70-73

通过SCCS自我和谐量表以及自编问卷,对2391名大学生体育态度对自我和谐影响做U检验和相关研究,实验结果表明:体育态度与自我和谐之间具有高度负相关性(相关系数为0.92).其中,男大学生体育态度得分高于女大学生;艺体类体育态度得分最高,理工次之,文史最差;大一学生体育态度得分最高,大二、大三次之,大四最差;在自我和谐度上,男大学生的自我和谐度优于女大学生;艺体类大学生自我和谐度最好,理工类次之,文史类最差;大一学生自我和谐度最好,大二、大三次之,大四最差.  相似文献   

一位院士的情怀对科技期刊编辑的启示——阅读《大家博友》《大师小文》的感悟   总被引：1，自引：0，他引：1  

宫福满 《编辑学报》2016,28(1):101-101

针对学术期刊数字化程度与影响力提升的效应问题,重点对江苏省17种中文地学类期刊的网络化建设及应用程度做了调研和量化分析,并将其数据与统计期刊近5年的影响因子和被引频次做了分析比较.结果显示,被统计期刊学术影响力指标的上升趋势,与评价期刊数字化应用程度高低的得分值有很好的对应关系.进一步分析结果表明,代表期刊数字化程度较高的微信运用,有可能对提升科技期刊学术影响力起到意想不到的推动作用.  相似文献   

利用GoWeb、PubMed及ISIS系统评价医学期刊对研究热点的把握度     

宋国营  常春  苏楠  张媛  郭瑞  石朝云  熊曾 《编辑学报》2016,28(5):453-456

以哮喘机制研究为例,使用GoWeb生物医学专业搜索引擎搜索学科领域研究热点,以PubMed文献检索服务系统来源的国外权威期刊和ISIS系统检索获得的国家自然科学基金项目为评价标准,比较国内权威医学期刊对学科领域研究热点及其发展趋势的把握度.结果发现,免疫学、气道重塑、表观遗传学为哮喘机制研究3大热点,三者发文量或项目数占比之和由高到低排列分别为《中华医学杂志》(96.0％)、国家自然科学基金项目(89.5％)、国外权威期刊(87.0％)、《中华结核与呼吸杂志》(75.7％).与国外权威期刊及国家自然科学基金项目相比较,国内权威期刊中免疫学机制比例较高,而气道重建比例较低,表观遗传学研究见于国外权威期刊、国家自然科学基金项目及《中华医学杂志》中,发文量或项目数占比基本相当;在国内期刊中,《中华医学杂志》对哮喘机制研究热点的把握度较好.基于GoWeb对科技期刊研究领域进行对比分析有利于医学期刊及其编辑把握有关领域的研究热点及其发展趋势,组织发表紧跟国际研究热点的高水平的医学科研论文.  相似文献   

Early Literacy and the Public Library: An Opportunity of a Lifetime (of Reading)     

Bill Ptacek 《Public Library Quarterly》2016,35(4):338-343

In this article, author Bill Ptacek says that the future is now, and, at least from the 1970s through today, in the field of early childhood work, the future has come so fast that it is constantly upon us. That reality means that those concerned about young children in libraries have been about adaptation on a continuing basis. In this world of rapid change, innovation is constant: City firefighters come to the libraries in uniform to read stories to children, library outreach specialists take programs to daycare centers in their communities, and staff members create a space in a library devoted to early childhood reading. This tradition of rapid change means that the early childhood staff of most large public libraries in North America is changing for the future on a regular basis. The work unit should be considered seriously as one model for 21st century public library reform.  相似文献