交叉三角形波纹通道的传热与流动特性的研究

为获得层流条件下交叉三角形波纹通道的传热和流动特性的实验数据,利用热线风速仪和热电偶对流过该设通道的风速和温度进行了测量,在充分考虑入口端流体力学和热力学效应情况下,对周期性通道的实验数据进行处理,并获得平均摩擦因数fD和平均努塞尔数NuD.将实验数据与Fluent数值模拟结果作了对比,误差结果小于±15%.     

高校电视台归属对其功能实现度的影响

高校电视台是一种传播校园信息、丰富高校文化生活的重要手段,高等学校对其要求不断趋向于普遍意义的教育电视媒体。高校电视台是否充分实现教育电视的功能、是否满足高等学校的发展建设需要成为了制约其发展壮大的瓶颈问题,而高校电视台归属是对其功能实现产生影响的本质原因。     

Implementation processes of online and offline channel conflict management strategies in manufacturing enterprises: A resource orchestration perspective

The rapid development of e-commerce is driving many traditional manufacturing enterprises to establish online channels. This typically leads to online and offline channel conflicts for these enterprises. Existing studies on channel conflict management primarily focus on describing the conflicts and discussing the types of strategies. Utilizing the case study method and taking the resource orchestration perspective as the theoretical lens, this study examines the implementation processes of online and offline channel integration and segmentation strategies in two Chinese manufacturing enterprises. The findings reveal the prerequisite to select online and offline integration and segmentation strategies, and specific resource orchestration actions and capabilities generated under the guidance of the integration and segmentation strategies. This study has theoretical implications to the online and offline channel conflict management strategies by extending the “what” question to the “how” question. In addition, this study also provides references to practitioners for selecting and implementing appropriate online and offline channel conflict management strategies.     

基于全渠道理论的图书馆资源建设与服务模式重构

[目的/意义]随着新一轮信息技术革命的深化,全渠道用户群体开始崛起,并改变着信息消费与利用形态。全渠道策略已经从单纯的商业层面扩展到社会层面,图书馆可以利用全渠道的理念与方法进行资源建设与服务模式的重构,更好地适应用户群体的变化,满足用户的需求。[方法/过程]引入全渠道理论,讨论全渠道理念与策略在图书馆资源建设与服务中的适用性,并据此提出相关实施建议。[结果/结论]图书馆引入全渠道策略可以更好地识别不同的服务阶段与服务方式,整合不同的服务主体,从而更好地为用户提供全方位的服务。     

数字内容传输渠道对消费者行为的影响研究

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。     

Charge transport in conducting polyaniline co-doped with sulfosalicylic acid and dodecylbenzoyl sulfonic acid

We prepared conducting polyaniline （PAn） co-doped with sulfosalicylic acid （SSA） and dodecylbenzoyl sultonic acid （DBSA） in micro-emulsive polymerization, and studied its charge transport behaviors based on the measurement of its electrical conductivity in the temperature range between 203 K and 298 K. The conductivity was found to increase with temperature, similar to the case in semiconductors. Analyzing the experimental data with three models, namely the charge-energy-limitedtunneling model, Kivelson model and the three-dimensional variable range hopping （3D-VRH） model demonstrated that these models all describe well the charge transport behaviors of PAn co-doped with SSA and DBSA within the mentioned temperature range. From calculation with the 3D-VRH model, the hopping distance of the conducting PAn is obviously larger than its localization length. The PAn doped with SSA and DBSA enjoys desirable crystallinity due to the co-doping of two functional sulfonic acids. The macroscopic conductivity may correspond to three-dimensional transport in the network of the bundles, and the metallic islands may be attributed to quasi-one-dimensional bundles.     

一种发动机液力悬置动特性研究

基于流体力学理论,研究发动机液力悬置惯性通道内阻尼力,建立一种液力悬置力学模型和数学模型,进行动特性仿真,从流体力学的角度分析了液力悬置的结构参数对其动态特性的影响。     

便携式超高频射频识别读写器设计

超高频读写器的便携式设计是射频识别（RFID）系统广泛应用的关键.为实现超高频RFID读写器的便携式设计,提出一种超高频RFID读写器的设计方案.硬件系统主要包括读写器的射频前端、功率放大器、功率检测、天线阻抗调谐电路等,在设计过程中考虑信道指标并对其进行评估;在对ISO/IEC18000-6的三种协议标准进行比较的基础上选用ISO/IEC 18000-6C协议,设计相应软件系统主要包括基带模块及防冲突碰撞模块.对硬件进行评估计算并结合硬件对软件进行验证及测试,结论如下：该读写器具有功率消耗低、体积小、接口丰富等便携式优点;硬件系统性能稳定;软件功能运行良好.上述设计有效实现了射频识别系统的便携式设计.     

Reliability and validity of field-based measures of leg stiffness and reactive strength index in youths

Abstract

The aim of the study was to assess the reliability of a mobile contact mat in measuring a range of stretch–shortening cycle parameters in young adolescents. Additionally, vertical leg stiffness using contact mat data was validated against a criterion method using force–time data. The reliability study involved 18 youths completing a habituation and three separate test sessions, while 20 youths completed a single test session for the validity study. Participants completed three trials of a squat jump, countermovement jump, and maximal hopping test and a single trial of repeated sub-maximal hopping at 2.0 Hz and 2.5 Hz. All tests were performed on the contact mat. Reliability statistics included repeated-measures analysis of variance, intraclass correlation coefficient, and coefficient of variation (CV), while the correlation coefficient (r) and typical error of estimate (TEE) were reported for the validity study. Squat jump height was the most reliable measure (CV = 8.64%), while leg stiffness during sub-maximal hopping, and reactive strength index produced moderate reliability (CV = 10.17–13.93% and 13.98% respectively). Measures of leg stiffness obtained from contact mat data during sub-maximal hopping were in agreement with the criterion measure (r = 0.92–0.95; TEE = 6.5–7.5%), but not during maximal hopping (r = 0.59; TEE = 41.9%). The contact mat was deemed a valid tool for measuring stretch–shortening cycle ability in sub-maximal but not maximal hopping. Although reliability of performance was generally moderate, the tests offer a replicable assessment method for use with paediatric populations.     

和谐社会建设下民族传统体育发展的途径

中华民族在几千年不同时期不同政治、经济和文化背景制约下所形成的民族传统体育,具有顽强的生命力和丰富的文化蕴涵。在社会主义和谐社会建设的精神指导下,民族传统体育结合自身发展的实践,通过学校体育培养和社区体育传播等途径来继承和发扬,使之更加璀璨。