砖混结构现浇混凝土板裂缝产生的原因与防治

砖混结构在住宅建筑中占据着主导地位,砖混结构现浇混凝土板裂缝问题成为影响结构安全、观感质量和使用功能的重要因素.对以往的竣工工程进行调查分析,对现浇混凝土板裂缝的基本特征进行统计,总结了出现裂缝的基本规律.从混凝土本身性能及混凝土组成材料的质量方面、设计方面、施工过程等产生裂缝原因进行分析,并针对相应原因提出防止措施.在以后的工程设计、施工过程中,按照措施的要求,进行实施和监控,基本解决了砖混结构现浇板的裂缝问题.     

正极辊压工艺的研究

引俄辊压设备的进粒系统对正极活性物质的流动性及形态均有较高的要求。本文通过对引俄辊压设备的进料系统进行理论分析后,改进了进料系统,降低了正极辊压设备对活性物质的流动性及形态的要求。改进后的辊压设备不必使用特殊处理的活性物质就能辊压正电极,从而降低了生产成本。经测试,使用传统工艺生产的正极活性物质,即可满足生产批量化,压制出厚度、重量均匀性较高的正电极。     

硫酸亚锡电解阳极板的改造

阳极板是隔膜电解法生产硫酸亚锡时阳极区的反应物。文章针对硫酸亚锡电解工序阳极板残极率高的问题,逐一进行了原因分析和采取的相应措施,并取得了较好的经济效益。     

道光《城口厅志》的三种印本

《城口厅志》应只有一种版本,即刘绍文主持的道光24年刻本。所见三种印本中,四川本印刷时间更早,书版的毁损程度较轻。城口本、重庆本印刷时间约晚50年,书版的毁损程度较重,但印刷质量较好,内容更完整,并增补有少量光绪年间的材料。城口本中的补正出自近人,讹误较多。     

扫叶山房创始年代考

目前学术界对清代著名书坊扫叶山房的创始年代有着不同的说法，其中主要代表有明万历说和明季说等。本文通过对各说的辨析，并考察扫叶山房主人洞庭席氏相关人物的情况，以及席氏购藏汲古阁《十七史》书版的经过，从而确定清乾隆后期当为扫叶山房真实的创始年代。     

倾斜柱塞泵运动参数的简便计算

本文推导了倾斜柱塞泵运行参数ρ随科盘倾角Φ变化的函数关系式,用此函数关系进行倾斜柱塞系的设计计算,比用传统的函数ρ=f（α）要简单,且比较精确。     

Validity and reliability of a novel optoelectronic device to measure movement velocity,force and power during the back squat exercise

This study analysed the validity and reliability of a new optoelectronic device (Velowin) for the measurement of vertical displacement and velocity as well as to estimate force and mechanical power. Eleven trained males with Mean (SD) age = 27.4 (4.8) years, completed an incremental squat exercise test with 5 different loads (<30–90% of their 1?repetition maximum) while displacement and vertical velocity of the barbell were simultaneously measured using an integrated 3D system (3D motion capture system + force platform) and Velowin. Substantial to almost perfect correlation (concordance correlation coefficient = 0.75–0.96), root mean square error as coefficient of variation ±90% confidence interval ≤10% and good to excellent intraclass correlation coefficient = 0.84–0.99 were determined for all the variables. Passing and Bablock regression methods revealed no differences for average velocity. However, significant but consistent bias were determined for average or peak force and power while systematic and not proportional bias was found for displacement. In conclusion, Velowin, in holds of some potential advantages over traditionally used accelerometer or linear transducers, represents a valid and reliable alternative to monitor vertical displacement and velocity as well as to estimate average force and mechanical power during the squat exercise.     

Analysis of 3D curve expansion of conical cam with oscillating tapered roller follower

This paper focuses on the analysis of running conditions and machining processes of conical cam with oscillating follower. We point out the common errors existing in the design and machining of the widely used plane expansion method of conical cam trough-out line. We show that the motion can be divided into two parts, i.e. the oscillating motion of oscillating bar and the rotary motion of oscillating bar relative to the conical cam. By increasing the rotary motion of oscillating bar, the motion path of tapered roller on oscillating bar (i.e. contour surface of conical cam) can be expanded on the cylinder. Based on these analyses, we present a creative and effective designing and machining method for 3D curve expansion of conical cam with oscillating follower.     

基于J2EE组件的企业信息安全访问策略

本文针对企业信息安全性及易维护性的要求，提出了一种建立在J2EE规范上的基于组件的企业信息访问模型，有三层结构组成。该模型将对数据的操作由组件进行限制与分流，从而保证信息操作的针对性与安全性，整个体系形成了不同用户对应不同组件的用户界面，不同格式的数据对应不同的数据处理组件的访问逻辑，实现了同时对程序和数据的访问控制。     

重力式膝伸肌力量训练器械动力传动凸轮轮廓设计

通过实验获得人体膝伸肌等动向心收缩的力矩-角度特征曲线，然后，采用工作位法，在一定范围内对伸膝力矩-角度特征曲线进行模拟，获得器械工作凸轮的力臂值和轮径值，完成膝伸肌动力传动凸轮轮廓的设计。设计凸轮提供的阻力矩更符合人体膝伸力矩，解决了器械的全载负荷问题和因起始力矩过大产生可利用惯性、肌肉易疲劳和器械噪声等一系列问题。设计具有普遍适用性，使用的工作位法适用同类器械动力传动凸轮轮廓的设计。