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111.
This study employed an online survey (N = 310) to explore how viewers’ motivations for social TV participation influence their involvement in social TV activities, their program commitment, and network loyalty. Findings show that social infotainment and social companionship are the primary motivations of social TV participation. However, only social infotainment significantly predicts the intensity of viewers’ social TV usage, which has a positive influence on program commitment and network loyalty. Additionally, the relationship between social TV usage and network loyalty is partially mediated by program commitment. These findings demonstrate the value of social TV to broadcasters and provide directions for initiating and maintaining long-term relationships with viewers. 相似文献
112.
Vortices are whirling disturbances, commonly found in nature, ranging from tremendously small scales in Bose-Einstein condensations to cosmologically colossal scales in spiral galaxies. An optical vortex, generally associated with a spiral phase, can carry orbital angular momentum (OAM). The optical OAM can either be in the longitudinal direction if the spiral phase twists in the spatial domain or in the transverse direction if the phase rotates in the spatiotemporal domain. In this article, we demonstrate the intersection of spatiotemporal vortices and spatial vortices in a wave packet. As a result of this intersection, the wave packet hosts a tilted OAM that provides an additional degree of freedom to the applications that harness the OAM of photons. 相似文献
113.
关键能力是高考评价体系“四层”的考查重点,作业是能力培养的重要载体.本文对生物学作业进行模型化、流程化和进阶化的设计,目的是建构思维模型、领悟探究过程和训练逻辑思维,促进学生思维的发展,以落实关键能力的培养. 相似文献
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经营业态总体上反映一个产业的经营结构、供需关系、运营方式和发展战略,其合理性、科学性决定着产业市场运行模式的成败。近20年来我国学术期刊已逐步形成以纸质版、网络与电子版多元发布的全媒体出版产品结构,但这同一内容的2种版本却一直分别由不同的供应链各自定价发行,人为地将一个市场裂解为2个市场,造成了价格脱离价值、市场相互抵消、边际成本上涨、营销模式混乱的状态,严重削弱了期刊的市场主体地位,扭曲了产业生态,牵制了期刊和图书馆等信息服务机构的数字化转型升级与高质量发展。为根本上破解这一制约产业发展的全局性难题,应构建供需合作共赢的“刊-网-馆”融合运营模式,大幅度降低产业运行消耗,打造学术期刊数字版云出版、传播和服务与纸质版集约化生产发行和馆配相结合的全媒体经营业态。 相似文献
117.
面向Y一代的大学图书馆用户服务 总被引:3,自引:0,他引:3
探讨了Y一代的概念、学习特征、对图书馆服务的需求,提出了大学图书馆针对Y一代用户改进服务的对策。 相似文献
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There has been a large literature in the last two decades affirming adaptive DNA sequence evolution between species. The main lines of evidence are from (i) the McDonald-Kreitman (MK) test, which compares divergence and polymorphism data, and (ii) the phylogenetic analysis by maximum likelihood (PAML) test, which analyzes multispecies divergence data. Here, we apply these two tests concurrently to genomic data of Drosophila and Arabidopsis. To our surprise, the >100 genes identified by the two tests do not overlap beyond random expectation. Because the non-concordance could be due to low powers leading to high false negatives, we merge every 20–30 genes into a ‘supergene’. At the supergene level, the power of detection is large but the calls still do not overlap. We rule out methodological reasons for the non-concordance. In particular, extensive simulations fail to find scenarios whereby positive selection can only be detected by either MK or PAML, but not both. Since molecular evolution is governed by positive and negative selection concurrently, a fundamental assumption for estimating one of these (say, positive selection) is that the other is constant. However, in a broad survey of primates, birds, Drosophila and Arabidopsis, we found that negative selection rarely stays constant for long in evolution. As a consequence, the variation in negative selection is often misconstrued as a signal of positive selection. In conclusion, MK, PAML and any method that examines genomic sequence evolution has to explicitly address the variation in negative selection before estimating positive selection. In a companion study, we propose a possible path forward in two stages—first, by mapping out the changes in negative selection and then using this map to estimate positive selection. For now, the large literature on positive selection between species has to await reassessment. 相似文献
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文章就如何有效管理与利用日益增多的节目资源,从节目资料的全面收集、科学整理以及实现节目资料价值最大化等方面谈一些看法。 相似文献