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基于CAS理论的维基百科序化机制研究 被引量:17
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作者 马费成 夏永红 《图书馆论坛》 CSSCI 北大核心 2008年第6期85-92,共8页
在阐述CAS理论的核心思想的基础上,描述了维基百科的复杂适应性特征,定义了网站、内容、用户和组织四种类型的有序度指标,对维基百科的有序性进行了评估,并对其序化机制进行了分析,提出"相信大众智慧的思想"和"促进信息... 在阐述CAS理论的核心思想的基础上,描述了维基百科的复杂适应性特征,定义了网站、内容、用户和组织四种类型的有序度指标,对维基百科的有序性进行了评估,并对其序化机制进行了分析,提出"相信大众智慧的思想"和"促进信息流通的机制"是维基百科成功地实现有序演化的关键因素。 展开更多
关键词 CAS理论 维基百科 序化机制
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Implications of mitochondrial DNA mutations and mitochondrial dysfunction in tumorigenesis 被引量:20
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作者 Jianxin Lu Lokendra Kumar Sharma Yidong Bai 《Cell Research》 SCIE CAS CSCD 2009年第7期802-815,共14页
Alterations in oxidative phosphorylation resulting from mitochondriai dysfunction have long been hypothesized to be involved in tumorigenesis. Mitochondria have recently been shown to play an important role in regulat... Alterations in oxidative phosphorylation resulting from mitochondriai dysfunction have long been hypothesized to be involved in tumorigenesis. Mitochondria have recently been shown to play an important role in regulating both programmed cell death and cell proliferation. Furthermore, mitochondrial DNA (mtDNA) mutations have been found in various cancer cells. However, the role of these mtDNA mutations in tumorigenesis remains largely unknown. This review focuses on basic mitochondrial genetics, mtDNA mutations and consequential mitochondrial dysfunction associated with cancer. The potential molecular mechanisms, mediating the pathogenesis from mtDNA mutations and mitochondrial dysfunction to tumorigenesis are also discussed. 展开更多
关键词 mitochondrial DNA mutation CANCER ROS APOPTOSIS
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Standardization of tritiated water by the CIEMAT/NIST and TDCR methods 被引量:1
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作者 WU YongLe LIU HaoRan +6 位作者 LIANG JunCheng LIU JiaCheng XIONG WenJun YUE HuiGuo LIU SenLin YANG YuanDi YUAN DaQing 《Science China(Technological Sciences)》 SCIE EI CAS CSCD 2015年第3期559-564,共6页
The activity of tritiated water has been standardized by two liquid scintillation counting methods:The CIEMAT/NIST method with the54Mn-standard efficiency tracing and the triple-to-double coincidence ratio(TDCR)method... The activity of tritiated water has been standardized by two liquid scintillation counting methods:The CIEMAT/NIST method with the54Mn-standard efficiency tracing and the triple-to-double coincidence ratio(TDCR)method.The samples were prepared with Ultima Gold TM AB liquid scintillation cocktail in low-potassium glass vials.In the application of the CIEMAT/NIST method,the computer program EMILIA was used to calculate the efficiency of3H and54Mn according to the KL1L2L3M atomic rearrangement model.And the detection efficiency of the TDCR counter was calculated using TDCR07 code,which makes it possible to allow for the potential asymmetry between the three photomultiplier tubes.The influence of stopping power and k B factor is discussed in the paper.When a power approach is adopted for the stopping power for electrons below 1ke V and k B is chosen to be 0.0075 cm/Me V,the relative deviation will be only 0.3%between the two methods. 展开更多
关键词 tritiated water the CIEMAT/NIST method the TDCR method k B factor the stopping power liquid scintillation counting
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Focal mechanisms of the Lushan earthquake sequence and spatial variation of the stress field 被引量:28
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作者 LUO Yan ZHAO Li +1 位作者 ZENG XiangFang GAO Yuan 《Science China Earth Sciences》 SCIE EI CAS CSCD 2015年第7期1148-1158,共11页
Using broadband seismic records from regional networks, we determined the focal mechanisms and depths of 37 earthquakes in the 2013 M7.0 Lushan earthquake sequence(3.4≤Mw≤5.1) by fitting the three-component waveform... Using broadband seismic records from regional networks, we determined the focal mechanisms and depths of 37 earthquakes in the 2013 M7.0 Lushan earthquake sequence(3.4≤Mw≤5.1) by fitting the three-component waveform data. The results show that the earthquakes are predominantly thrust events, with occasional strike-slip mechanisms. Most earthquakes occurred at depths of 10–20 km. We derived the regional distribution of the average stress field in this area using the damped linear inversion method and the focal mechanisms obtained in this study. The inversion results suggest that the Lushan region and the adjacent area are mostly under compression. The orientations of the maximum principal axes trend NW-SE, with some local differences in the stress distribution at different depths. Compared with the distribution of the stress field in the Wenchuan earthquake area, the stress field in the southwest section of the Longmenshan Fault zone(LFZ) share similar characteristics, predominantly thrust faulting with a few strike-slip events and the maximum compression axes being perpendicular to the LFZ. 展开更多
关键词 Lushan earthquake focal mechanisms stress field aftershock sequence
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