商业模式动态演化机制：基于互联网业的多案例内容分析          下载免费PDF全文

张新香  胡立君 《科研管理》2018,39(3):110-121

本文根基商业模式内涵，构建商业模式结构模型，依据发展历程收集5家代表案例企业时间序列新闻文献和数据资料，运用内容分析法结构化分析文献资料，提炼互联网业商业模式动态演化规律和演化路径。研究显示：互联网业商业模式中，价值定义、价值实现、价值创造与传递三大构件的主导地位依次更替，对应呈现出客户价值实现、企业价值实现和网络价值实现的纵向三阶段演化模型，三阶段模型在时间跨度和运营绩效上与企业生命周期的创业期、发展期和成熟期很好吻合，商业模式的三大构件同样呈现出动态演化特征。本研究试图打开商业模式的组成结构黑箱，将商业模式的设计理论从静态视角升级到动态层面，为互联网业的发展给出可行的实践参考。  相似文献   

数字内容传输渠道对消费者行为的影响研究          下载免费PDF全文

朱建学  熊励 《科研管理》2018,39(9):42-51

根据个人理性约束和激励相容约束，基于期望效用理论构造了数字内容消费者行为模型，运用计算机仿真技术分析了消费者的数字内容消费数量及其效用变化情况，研究了数字内容传输分发渠道对消费者行为的影响。研究结果表明：（1）在传统传输分发渠道下，数字内容价格对消费者数字内容消费数量及其效用影响显著，是影响消费者行为的重要因素；（2）在数字化网络传输分发渠道下，会员制收费模式的会员费直接影响消费者效用，按交易量收费模式通过数字内容消费数量间接影响消费者效用；（3）在双重传输分发渠道下，消费者效用和数字内容消费数量均高于上述传输分发渠道。综上可得，双重传输渠道更加符合消费者利益，为了体现消费者日益增强的影响力和主导权，数字内容供应商应该实施双重传输分发渠道策略。  相似文献   

不同负荷运动训练对大鼠骨骼肌线粒体三羧酸循环的影响及其机制研究     

李洁  杨静  赵丽丽 《武汉体育学院学报》2019,53(5):88-94

目的：探讨不同负荷运动训练对大鼠骨骼肌线粒体三羧酸循环的影响及其机制。方法：将雄性Wistar大鼠50只随机均分为5组：安静对照组（C）、低负荷运动训练组（LT）、中等负荷运动训练组（MT）、高负荷运动训练组（HT）和极高负荷运动训练组（ST），每组10只。各运动组分别进行6周的跑台运动训练。训练方案结束后，取腓肠肌样本，提取线粒体，测定线粒体柠檬酸合成酶（CS）、异柠檬酸脱氢酶（ICD）和α-酮戊二酸脱氢酶（α-KGDHC）活性；线粒体Ga²⁺含量、胞浆NADH、NAD⁺、ATP和ADP含量，以及ICD mRNA转录水平。结果：（1）不同负荷运动训练组线粒体CS、ICD和α-KGDHC的活性均显著高于安静对照组（P < 0.01），且CS和ICD活性由高到低顺序均为：MT组 > HT组 > ST组 > LT组 > C组，α-KGDHC活性由高到低顺序为：HT组 > MT组 > ST组 > LT组 > C组。（2）不同负荷运动训练组线粒体Ca²⁺ 含量均显著高于安静对照组（P < 0.01），其含量由高到低顺序为：MT组 > HT组 > ST组 > LT组 > C组；胞浆NADH/NAD⁺和ATP/ADP的比值均显著低于安静对照组（P < 0.01），其比值由低到高顺序为：MT组 < ST组 < HT组 < LT组 < C组。（3）不同负荷运动训练组ICD mRNA转录水平均高于安静对照组（P < 0.01），其水平由高到低顺序为： MT组 > HT组 > ST组 > LT组 > C组。结论：低负荷、中等负荷、高负荷及极高负荷运动训练均可提高大鼠骨骼肌线粒体三羧酸循环功能，且中等负荷运动训练效果最佳。其机制与胞浆NADH/NAD⁺和ATP/ADP比值、线粒体摄钙能力及限速酶基因的表达有关。  相似文献   

Structure and development of pre-service physics teachers’ professional knowledge     

Stefan Sorge  Jochen Kröger  Stefan Petersen  Knut Neumann 《International Journal of Science Education》2019,41(7):862-889

ABSTRACT

Teachers’ professional knowledge is considered one of the most important predictors of instructional quality. According to Shulman, such professional knowledge includes content, pedagogical content and pedagogical knowledge. Although recent research shed some light on the structure of the dimensions of professional knowledge, little is known how teacher education impacts pre-service physics teachers’ professional knowledge. In an effort to address this issue, we examined the content, pedagogical content and pedagogical knowledge of N?=?200 pre-service physics teachers enrolled in different years of teacher education at 12 major teacher education universities in Germany. We used structural equation modelling (1) to examine the relations amongst pre-service physics teachers’ content, pedagogical content and pedagogical knowledge, (2) to explore how the three kinds of knowledge and their relations differ across different stages of teacher education and (3) to identify factors affecting the level of each component of professional knowledge. Our findings suggest that content, pedagogical content and pedagogical knowledge represent distinct types of knowledge. Furthermore, our findings show that in the first years of professional education, pedagogical content knowledge is more closely related with general pedagogical knowledge while in later years, it is more closely related with content knowledge, suggesting that it develops from a general knowledge about teaching and learning into knowledge about the teaching and learning of specific content. Finally, beyond school achievement and years of enrolment as predictors, we find in particular the amount of classroom observations to have a positive impact on the professional knowledge of pre-service physics teachers.  相似文献   

Probing the amalgam: the relationship between science teachers’ content,pedagogical and pedagogical content knowledge     

Knut Neumann  Vanessa Kind  Ute Harms 《International Journal of Science Education》2019,41(7):847-861

ABSTRACT

This Special Issue aims to present evidence about the relationships between content knowledge (CK), pedagogical knowledge (PK) and pedagogical content knowledge (PCK); the development of these types of knowledge in novice and experienced secondary science teachers; and how CK, PK and/or PCK impact students’ learning. Since Shulman’s introduction of PCK as the feature that distinguishes the teacher from the content expert, researchers have attempted to understand, delineate, assess and/or develop the construct in pre- and in-service teachers. Accordingly, empirical findings are presented that permit further discussion. Outcomes permit post-hoc examination of a recent, collectively described, ‘consensus’ model of PCK, identifying strengths and potential issues. As we will illustrate, the relationship between CK, PK and PCK is central to this; that is, probing the hypothesis of pedagogical content knowledge as an ‘amalgam’ of content and pedagogical knowledge.  相似文献   

Psychological support for sport coaches: an exploration of practitioner psychologist perspectives     

Sarah Kelly  Richard Thelwell  Jamie B. Barker  Chris G. Harwood 《Journal of sports sciences》2018,36(16):1852-1859

In the present study we add to the literature by exploring the degree to which UK practitioner psychologists perceive themselves able to support sport coaches, and how professional training prepares psychologists for coach work across performance domains. Ten participants comprising seven sport and exercise psychologists with Health Care Professions Council (HCPC) practitioner psychologist status and three trainee psychologists studying towards the British Psychological Society (BPS) qualification in sport and exercise psychology (QSEP) were individually interviewed. All participants reported prior experience of working with coaches across all performance domains. We explored: practitioner’s understanding of the challenges coaches face within their job; practitioner’s experiences of coach work; perspectives about the ways in which practitioners could and should support coaches; and, the degree to which professional training prepares practitioners for coach work. Using recommended procedures of Connelly and Peltzer, content analysis revealed practitioners perceived the challenges faced by coaches are different at grassroots level compared to those working with elite athletes, and that practitioners require skills to provide one-to-one coach support and group-based interventions. All practitioners perceived that training programmes do not adequately equip trainees with skills required for coach work. We discuss the implications for enhancing practitioner training in the UK.  相似文献   

后发地区创新创业模式及优化研究          下载免费PDF全文

汪明月  刘宇  秦海波  李梦明 《科研管理》2018,39(9):68-77

成功实施创新创业战略的后发地区究竟是采取了什么样的发展模式？模式的选择受到什么要素的影响及优化的方式是什么？既往的研究还未做出较为深刻地解释与回答。本研究基于南昌、郑州与贵阳创新创业发展案例的数据进行探索性研究，总结归纳了中国后发地区推进创新创业的发展模式及优化的内在规律。理论发展模式表明：后发地区推进双创的基础在于识别区域发展的潜在优势，潜在后发优势的发挥需要通过优化人力、资金、载体、技术、制度与文化要素来实现。推进后发地区双创发展要通过制定和完善相应的政策体系来引导要素的定向配置；构建实体平台或互联网虚拟平台实现要素的空间集聚；营造双创文化来提升要素的内在动力。相较于现有的侧重于先发地区创新创业的理论与实践，基于后发地区双创模式分析能够从宏观层面打开双创模式选择的“黑箱”。  相似文献   

体育明星电视广告代言研究          下载免费PDF全文

孙文树 《河北体育学院学报》2019,33(1):28-33

以中央五频道2013—2015年间播放的电视广告为样本，采用内容分析法对体育明星的电视广告代言情况进行分析。结果显示：①体育明星进行电视广告代言的比例非常高，占27.66%；而在电视商业广告中，这一数字达到了36.05%，说明体育明星在电视广告中的流行程度非常高。②电视广告中体育明星的代言内容十分广泛，以汽车、公益、体育用品、酒类、赛事、媒体、企业形象、饮品等八类为主，并且体育相关产品的51.0%、非体育相关产品的25.7%都是由体育明星来代言的。③体育明星代言电视广告的数量与奥运会密切相关，企业选择体育明星作为代言人受体育明星的流行程度、匹配性、领域地位等因素的影响。④未来体育明星电视广告一定程度上会受移动广告的冲击，但是体育娱乐化也进一步拓宽了体育明星代言电视广告之路。  相似文献   

Mini-research Experience in Simple Linear Regression     

Paul Isihara  Elisabeth Congdon  Terry Perciante 《PRIMUS》2018,28(7):699-716

Within the undergraduate mathematics curriculum, the topic of simple least-squares linear regression is often first encountered in multi-variable calculus where the line of best fit is obtained by using partial derivatives to find the slope and y-intercept of the line that minimizes the residual sum of squares. A markedly different approach from linear algebra, which could also be introduced in multi-variable calculus, obtains the regression line by vector projection. The latter viewpoint offers elegant proof of the equation relating the total, explained and unexplained variations. Consideration of data with the same regression line and correlation opens the door for a “mini-research experience” (MRE). A sequel MRE gives rise to an open Research Experience for Undergraduates topic to analyze reflection sequences and a fundamental connection between complex analysis and regression analysis. A few general guidelines and basic goals for MREs are included for those whose main interest is in undergraduate research.  相似文献   

Content Analysis of Google Alerts for Cultural Heritage Institutions     

Elizabeth Joan Kelly 《Journal of Web Librarianship》2018,12(1):28-45

This article outlines evidence-based methods for cultural heritage institutions to look for news and mentions about their collections and services online. Google Alerts were created for repository names, websites, and finding aid websites for 66 institutions randomly selected from the Archive Grid database. Results were analyzed to determine Google Alerts' accuracy, what types of institutions would benefit most from using Google Alerts, what the content of the sources found by the alerts was, what types of publications returned the most results, and if Google Alerts could also identify image reuse. While Google Alerts' accuracy for returning usable results for analysis was not very high, the structure of alert e-mails makes discarding irrelevant results simple and quick. Mid- to large-sized museums and institutions staging frequent exhibits and events, as well as those with active collections, return the largest number of alerts. News publications and social media publish the most content related to cultural heritage institutions. Though the sample set was small, Google Alerts also was able to identify image reuse.  相似文献