砖混房屋现浇楼板裂缝原因分析及对策

长期以来 ,砖混结构现浇楼盖裂缝问题令许多工程技术人员感到棘手 ,且近年来日趋严重。结合一幢砖混结构宿舍楼现浇楼板裂缝实例 ,计算分析了该种结构现浇楼板常见裂缝产生的原因 ,并提出了相应的处理和预防措施。后续类似工程证明所建议的裂缝预防措拴是有效的。     

乳化液废水处理浅议

介绍了乳化油在水中的存在形态，结合化学法处理乳化废液中乳化油的处理机理，对乳化液的具体处理工程进行了探讨，提出了使设备投资和工程造价显著降低的措施。     

GPS在城市控制测量应用中的几点体会

文章以阜阳市G PS控制网改造为例,从G PS网的构成、观测、数据处理、精度评定等方面加以论述,对G PS在城市控制测量中的优越性与实用性等问题作了相关探讨。     

新一代本币交易系统的综合性能测试实践

为测试多市场金融交易平台的性能,提出一种基于LoadRunner测试平台的综合性能测方法,通过搭建模拟测试环境和软件模拟大批量在线并发用户等方法,严格按照性能测试实施流程,实现了对交易平台的系统容量、系统处理能力、客户端响应时间、系统可靠性和安全性等指标的测试,取得了较好的验证和评估效果。     

载人月球车等效侧倾刚度和阻尼计算方法

载人月球车是月面探测必不可少的探测工具,以载人月球车为主的月面活动技术是载人探月及建立月球基地的关键技术。载人月球车移动系统作为承载平台不仅要承担一定的重量,还要保证宇航员在行驶中安全,需要研究其操纵稳定性,而在进行其操纵动力学建模时,等效侧倾刚度和阻尼取值的准确性直接影响其侧翻安全性计算的准确性。在通过对双横臂扭杆悬架结构的载人月球车瞬时侧倾刚度和阻尼进行数学建模时,发现其随车身的侧倾运动发生变化,而不为定值;当采用整个侧倾运动过程中的能量等效的方法,得到的等效侧倾刚度随车身的侧倾运动变化较小,接近定值。因此对不同的等效侧倾刚度与阻尼的取值方法下操纵动力学方程的计算结果与载人月球车的操纵动力学仿真结果进行对比与分析,得到较为精确的等效侧倾刚度和阻尼的取值方法,为载人月球车的操纵动力学和侧翻安全性的研究奠定基础。     

GSM多功能基站无线语音通信研究

基于GSM多功能基站的手机终端接入功能,实现其语音通信功能。首先开通基站的语音呼叫业务,然后将原始语音形成语音发送脉冲,最后将手机锁定在基站工作,对语音功能进行测试。根据多功能基站的功能和性能要求,不仅实现其语音通信功能,且使之具有呼叫异常处理能力,功能设计上相对商用基站也作了一些改进。实验证明：锁定在多功能基站工作的手机能收到基站发送的语音信息。     

Constrained Efficient Global Optimization for Pultrusion Process

Composite materials, as the name indicates, are composed of different materials that yield superior performance as compared to individual components. Pultrusion is one of the most cost-effective manufacturing techniques for producing fiber-reinforced composites with constant cross-sectional profiles. This obviously makes it more attractive for both researchers and practitioners to investigate the optimum process parameters. Validated computer simulations cost less as compared to physical experiments, therefore this makes them an efficient tool for numerical optimization. However, the complexity of the numerical models can still be “expensive” and forces us to use them sparingly. These relatively more complex models can be replaced with “surrogates,” which are less complex and are therefore faster to evaluate representative models. In this article, a previously validated thermochemical simulation of the pultrusion process has shortly been presented. Following this, a new constrained optimization methodology based on a well-known surrogate method, i.e., Kriging, is introduced. Next, a validation case is presented to clarify the working principles of the implementation, which also supports the upcoming main optimization test cases. This design problem involves the design of the heating die with one, two, and three heaters together with the pulling speed. The results show that the proposed methodology is very efficient in finding the optimal process and design parameters.     

测量长期光辐射下人眼对比度敏感函数及模型

正常环境下研究得出的对比敏感度函数模型,在人眼受长时间高亮度电脑或手机显示屏光辐射(即视觉异常)时不再适用。文中基于正弦光栅的计算公式在Matlab中编程得到了实验所需的正弦光栅。由于在不同光谱功率分布下的对比敏感度值会有较大差别,实验基于LCD显示器得出视觉异常实验者在不同光谱功率分布(日光,灯光)下的对比敏感度值和CSF曲线。并通过非线性最小二乘法得出视觉异常时CSF模型。其结果表明,视觉异常时人眼最敏感空间频率和光学成像能力均发生了较大变化,且节能灯和显示屏等非自然光源与自然光源日光相比其光谱功率分布对人眼对比敏感度的影响最大。     

Passive acoustic emissions from particulates in a V-blender

Context: Regulatory agencies are recommending the development of process analytical technologies (PAT) to improve the efficiency and product quality during pharmaceutical manufacturing.

Objective: The objective of the research was to investigate the potential application of passive acoustic emission monitoring of a V-blender.

Materials and methods: Trials were conducted with sugar spheres, lactose or MCC in a V-blender. Vibrations from acoustic emissions were measured using PCB Piezotronics accelerometers with ICP signal conditioners.

Results and discussion: A wavelet filter was applied to the measured acoustic emissions to remove vibrations from the tumbling motion of the V-shell, allowing a focus on information about particle motion and interactions within the V-shell. The ideal sensor location was determined to be the lid of one of the V-shell arms due to the impact of the tumbling particles on the lid and transmission of the vibrations from other particle motion within the V-shell. The amplitude of vibrations increased with particle size due to larger particle momentum before a collision. The fill level and the V-shell scale also influenced the measured vibrations as particle motion was affected which in turn affected momentum. Changes in particle flowability could be detected through variations in the measured acoustic emissions.

Conclusion: The measured vibrations from passive acoustic emissions reflected particle motion and interactions within a V-blender demonstrating potential as a monitoring method.     

矿用隔爆型移动变电站的维护与故障处理

保证矿用隔爆型移动变电站的安全可靠运行,已成为煤矿供电安全管理的重要工作内容。结合矿用隔爆型移动变电站在煤矿安全生产中的实际应用情况,对移动变电站的基本特征、工作原理、操作维护方法等方面存在的问题进行常见故障分析,并提出相应的解决措施;在解决故障的同时,对操作过程进行了优化,使之更加安全规范。分析认为,熟悉设备基本性能,提高快速排除各种故障的技能,可以为煤矿供电系统的安全可靠提供保障。