外显生长指数

基于一篇文章所引用的参考文献和该文的被引频次两个维度,提出了衡量该文外显成长度的相对指标.该研究涉及的引用数据及每条参考文献的被引数据均来自网络版科学引文索引(Web of Science),检索日期为2010年4月最后一周.     

克劳德·申农:科学家与工程师(英文)

2 0 0 1年初克劳德·申农逝世了 .本文对申农的生平做了总体介绍 .申农是许多科学领域的先驱 :他在开关理论中引入了布尔代数 ,他是通讯理论之父 ,他还做过一些人工智能方面的实验 .这里 ,我们着重介绍他的工作与信息科学的关联 .此外 ,也描述了他对n grams的运用 .最后 ,我们对n grams在信息科学领域的应用做了一般性讨论     

On indexing in the Web of Science and predicting journal impact factor

We discuss what document types account for the calculation of the journal impact factor （JIF） as published in the Journal Citation Reports （JCR）. Based on a brief review of articles discussing how to predict JIFs and taking data differences between the Web of Science （WoS） and the JCR into account, we make our own predictions. Using data by cited-reference searching for Thomson Scientific＇s WoS, we predict 2007 impact factors （1Fs） for several journals, such as Nature, Science, Learned Publishing and some Library and Information Sciences journals. Based on our colleagues＇ experiences we expect our predictions to be lower bounds for the official journal impact factors. We explain why it is useful to derive one＇s own journal impact factor.     

Purification and reconstitution of the calcium release channel from skeletal muscle

The calcium release channel from rabbit muscle sarcoplasmic reticulum (SR) has been purified and reconstituted as a functional unit in lipid bilayers. Electron microscopy reveals the four-leaf clover structure previously described for the 'feet' that span the transverse tubule (T)-SR junction. Ca2+ release from the SR induced by T-system depolarization during excitation-contraction coupling in muscle may thus be effected through a direct association of the T-system with SR Ca2+-release channels.     

血管成形术和Stent放置术放射治疗后动脉损伤的治疗

用于评价经皮穿刺血管成形术和Ｓｔｅｎｔ在放疗后所致动脉疾病的治疗,及靶血管内Ｓｔｅｎｔ的长期支撑开放作用。资料和方法：１４例患者,因为放疗所致１８处动脉性病变,而给予血管成形术治疗。１３个Ｓｔｅｎｔ放置于８个患者,分别治疗血管闭塞３例,内膜撕裂１例,动脉瘤１例,残存狭窄２例,多发狭窄１例,球囊成形术后再发狭窄１例。所有病例均用ＣＴ扫描和／或多普勒超声检查,观察Ｓｔｅｎｔ及其靶血管内和Ｓｔｅｎｔ内的血流情况。结果：血管成形术成功治疗１４例病人,８例患者在动脉病变处放置Ｓｔｅｎｔ。１１例动脉病基本消失,追踪２年（８月～５年）,临床症状完全解除,３例临床症改善。１１例患者接受了１或２次血管成形术。１例患者重复承受了４次血管成形术,并放置３个Ｓｔｅｎｔ,２个Ｓｔｅｎｔ放在两髂总动脉和腹主动脉,１个Ｓｔｅｎｔ放在腹腔动脉。另１位重复４次血管成形术的患者,在肠系膜上动脉放了２个Ｓｔｅｎｔ。最后１例,因为血管成形术后内膜撕裂和血管闭塞,而放置了１个Ｓｔｅｎｔ,经５年随防,其动脉病变为临床治愈。结论：单一的血管成形术或者多技术综合运用,可有效治疗放疗所致的动脉性病变,应考虑其为动脉损伤性病变的首选治疗     

A multi-metric approach for research evaluation

Background information is provided about the Web 2.0 related term altmetrics. This term is placed in the context of the broader field of informetrics. The term influmetrics is proposed as a better term for altmetrics. The importance of considering research products and not just scientific publications is highlighted. Issues related to peer review and making funding decisions within a multi-metric approach are discussed and brought in relation with the new metrics field.     

Host sanctions and the legume-rhizobium mutualism

Explaining mutualistic cooperation between species remains one of the greatest problems for evolutionary biology. Why do symbionts provide costly services to a host, indirectly benefiting competitors sharing the same individual host? Host monitoring of symbiont performance and the imposition of sanctions on 'cheats' could stabilize mutualism. Here we show that soybeans penalize rhizobia that fail to fix N(2) inside their root nodules. We prevented a normally mutualistic rhizobium strain from cooperating (fixing N(2)) by replacing air with an N(2)-free atmosphere (Ar:O(2)). A series of experiments at three spatial scales (whole plants, half root systems and individual nodules) demonstrated that forcing non-cooperation (analogous to cheating) decreased the reproductive success of rhizobia by about 50%. Non-invasive monitoring implicated decreased O(2) supply as a possible mechanism for sanctions against cheating rhizobia. More generally, such sanctions by one or both partners may be important in stabilizing a wide range of mutualistic symbioses.     

The R- and AR-indices： Complementing the h-index

Based on the foundation laid by the h-index we introduce and study the R- and AR-indices. These new indices eliminate some of the disadvantages of the h-index, especially when they are used in combina-tion with the h-index. The R-index measures the h-core’s citation intensity, while AR goes one step further and takes the age of publications into account. This allows for an index that can actually in-crease and decrease over time. We propose the pair (h, AR) as a meaningful indicator for research evaluation. We further prove a relation characterizing the h-index in the power law model.     

Hirsch 指数研究的新进展

提出了离散Hirsch 指数（简称h 指数）的精确定义，引入了“Hirsch 核心”这一概念。不仅将h 指数推广到实数集，还介绍了其他相关的派生指数，g 指数和A 指数。只有h 指数和g 指数相结合，才能较全面地评价科学家的科研成就。