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61.
62.
第三代移动通信技术替代进程分析 总被引:5,自引:0,他引:5
第三代移动通信技术支持高速移动多媒体业务 ,全面突破了传统移动语音通信模式 ,将给社会经济生活带来重大影响 ,它的渐进性的技术替代进程既受到新技术本身实际性能改进程度的影响 ,又受到新技术替代旧技术成功程度的的示范效应影响 ,对技术替代进度可以从时间和空间维度两方面进行考虑 ,把握技术替代的节奏和重点 相似文献
63.
基于3G技术的手机图书馆服务探讨 总被引:1,自引:0,他引:1
3G技术的发展为图书馆移动信息服务提供了新的平台。基于3G技术构建手机图书馆可使图书馆服务更加丰富和高效。简述了3G时代手机图书馆的发展概况,着重探讨了手机图书馆的服务。 相似文献
64.
This paper addresses the role that scientific status plays in initial public offerings of technology focused firms. The paper builds on the literature of the sociology of science as well as the work of Spence (1974) and Podolny (1993) and argues that the presence of a Nobel laureate affiliated with a firm making an IPO provides a signal of firm quality to potential investors. Moreover, and building on the work of Podolny and Scott Morton (1999) and Stuart et al. (1999) we hypothesize that the importance of status diminishes as other measures of firm quality become available. We test our hypothesis for two periods of initial public offerings in biotechnology. We document that there is a clear difference in “maturity” of the firms across the two windows on a number of metrics. Consistent with our hypothesis that Nobel laureates play an important role as a non-financial signal of firm quality, we find that first-window firms with a Nobel laureate affiliate realize greater IPO proceeds in the amount of $24 million. In the second window the amount of money raised is not significantly different between Nobel and non-Nobel firms. This finding is consistent with the signaling literature that argues that the importance of a signal is inversely related to the availability of cogent information on firm quality. Consistent with this view, we also find a change between the two windows in the importance of other non-financial metrics used to convey value. Our research is one of the first to examine the dynamic nature of signals. Because we are unable to distinguish the extent to which the reduction in uncertainty at the firm level is correlated with the reduction of uncertainty at the industry level, the question remains as to the extent to which the diminished importance of signals in our second period is due to a change in market uncertainty versus a change in firm uncertainty. 相似文献
65.
66.
3G时代的手机图书馆 总被引:1,自引:1,他引:0
论文分析3G环境下建立手机图书馆的可行性,介绍国内手机图书馆的发展状况,详谈图书馆利用3G技术和手机开展的新型服务,最后提出构建手机图书馆的问题与对策. 相似文献
67.
Upendra Yadav Pradeep Kumar Vandana Rai 《Indian journal of clinical biochemistry : IJCB》2021,36(1):23
Methionine synthase reductase (MTRR) is an important enzyme of the folate/homocysteine pathway. It is responsible for regulation of methionine enzyme by reductive methylation. A common variant A66G is reported in the FMN-binding domain of the MTRR gene, which leads to substitution of isoleucine by methionine (I22M) in MTRR enzyme with reduced activity. Reduced catalytic activity of enzyme leads to high homocysteine concentration in blood and increases risk for numerous diseases. The frequency of A66G polymorphism varies in different ethnic groups. The present study has been designed to evaluate the frequency of MTRR A66G gene polymorphism in the Eastern UP population by PCR–RFLP method. Along with this we also performed a meta-analysis to evaluate the global prevalence of this polymorphism. Databases were screened to identified the eligible studies. The prevalence of the G allele and GG genotype was determined by the use of prevalence proportion with 95% CI. Open meta-analyst software was used for the meta-analysis. Total 1000 blood samples were analyzed, the frequencies of A and G alleles were 0.35 and 0.65 respectively. Meta-analysis results revealed that the prevalence of G allele and GG genotype were 49.4% (95% CI 40.6–58.1, p ≤ 0.001) and 24.3% (95% CI 17.8–30.9, p ≤ 0.001) respectively. In sub-group meta-analysis, the lowest frequency of G allele was found in South America (32.7%; 95% CI 14.1–51.3, p ≤ 0.001), and highest in Asia (56.4%; 95% CI 39.5–73.3, p ≤ 0.001). The results of the meta-analysis showed that the Asian population has the highest frequency of G allele and highest frequency of the GG genotype was found in the European population. 相似文献
68.
朱凯 《洛阳师范学院学报》2014,(2):61-63
20122013年,3G、4G竞相争辉,我国移动通信事业的发展即将迎来再一次的飞跃.文章分析我国3G、4G的发展现状,剖析当前3G、4G网络发展存在的问题,说明3G与4G的相互关系和发展的趋势,最后对4G发展作出展望. 相似文献
69.
张繇曦 《湖南广播电视大学学报》2014,(2):41-46
20世纪70年代以来,分析马克思主义作为西方马克思主义的主流开始流行,作为分析马克思主义的领军人物,G.A.科恩见证了它的繁荣和衰退。那至于为何衰退?或许G.A科恩在展示马克思拜物教思想时已见端倪。他在解读马克思拜物教思想的逻辑起点和基本内容后,呼吁消灭形式的统治,实现内容的解放,为共产主义的历史必然实现作了辩护。 相似文献
70.
当前正处于后WEB2.0时代的“网络信息社会”,随着信息技术的发展,将进入到WEB3.0时代:网站内的信息可以直接和其他网站相关信息进行交互。并且用户在互联网上拥有的自己的数据,用浏览器即可以实现复杂的系统程序才具有的功能。当WEB技术逐步发展进入到WEB3.0时期时,企业的品牌传播模式将会有显著的变化。它将使得基于智能手机、微博及微信的品牌传播更具个性化、可信度及可控性,从而提高传播效果。 相似文献