被动式建筑空气龄和热舒适度的数值分析

为研究地下室和通风井以及通风井开口面积对被动式建筑室内空气龄和热环境的影响。我们利用计算流体力学软件PHOENICS对上述情况进行模拟研究。模拟结果表明:设置地下室和通风井将有利于室内空气品质的提升和热环境的改善;建筑单独设置通风井对空气龄的影响较大,对热环境的影响较小;当通风井开口面积与横截面积之比分别为2/3、1/2、1/3时,取通风井开口面积与横截面积之比为1/2,则一楼空气龄和室内热环境为最佳。     

Numerical Simulation of Energy Saving Potential in Dispersing Process of Blasted Smoke in Mines

The dispersing process of the blasted smoke in underground mines by ventilation is very important for the safety of personnel, and its energy consumption is also worthy of concern. In this study, the impact of supply air flow rate on the decay process of harmful gases and fan energy, and the role of harmful gases buried by blasted pile in the smoke dispersing process is analyzed with three-dimensional numerical simulation. According to the results, air flow facilitates quick smoke dispersion and the gas emits from the blasted pile is only significant at the beginning of ventilation. It is thus recommended that large amount of air supply is taken to disperse the smoke quickly until the concentration of harmful gases reaches relevant standards, and reduce the amount of air in the remain time with frequency conversion technology to save energy. In the given study, 12 m/s air flow rate is taken for dispersing smoke and 3 m/s air flow rate is taken for the waiting time. The energy consumption for ventilation is reduced by about 50％. In addition, due to the gases in the blasted pile remains very high concentration after the dispersing process, it is recommended to keep suitable amount of ventilation in the consequent process.     

基于通风系统的高瓦斯基建矿井巷道施工优化

基建矿井主、副（风）井贯通后,且在进入二期工程前必须形成全风压通风系统,此时,井下工程仍需采用地面局部通风机供风。由于井筒直径限制,布置的风筒数量极其有限,导致工程施工无法全面展开,严重制约了矿井的建设速度。本文以古城煤矿的建设为例,分析了施工现状存在的问题,提出了高瓦斯基建矿井的施工应充分考虑现有和未来一段时间临时通风系统的变化情况,并结合瓦斯治理工程实施方案,优化巷道施工顺序,为局部通风机入井运行及井下工程的全面开展奠定基础。     

与发达国家铸造业通风除尘环保技术方面的差距——德国考察的体会与思考

详细介绍了Busch铸造公司、Tweer铸造厂、Baumgarte铸造厂、宝马汽车铸造厂及GF—Singen铸造厂的除尘系统配置情况和实际效果，分析指出德国工厂环境保护意识强、除尘技术先进可靠、工艺设备密闭性好．并且强调供排风的平衡和重视旧砂再生技术。     

低频脉冲电流退火对CoFeSiB非晶薄带巨磁阻抗效应的影响

研究了经不同低频脉冲电流密度退火的Co66.3Fe3．7Si12B18非晶薄带的巨磁阻抗（GMI）效应。结果表明，在低频脉冲电流下，巨磁阻抗效应的大小与退火电流密度密切相关。非晶带的GMI变化率△Z／Z先随退火电流密度的增加而增强，当电流密度为104A／mm^2时，△Z／Z达到最大值53．8％，此后随电流密度增大，GMI变化率开始减小。对脉冲电流退火影响巨磁阻抗效应的机制作了定性分析。并分析了由脉冲电流退火在材料内感生的横向各向异性场凤对GMI效应的影响，发现HK有利于提高GMI效应的峰值，但同时存在一个临界值，当超过这个值时，GMI效应的峰值减弱。     

分缝分块对金安桥大坝混凝土温度应力的影响分析

金安桥碾压混凝土重力坝最大坝高160 m,顺流向最大长度156 m。通过对坝体混凝土通仓浇筑和横缝间距对温度应力的影响分析,确定大坝混凝土采用通仓浇筑,同时为控制和减少温度应力引起的劈头裂缝,在坝体上游面设置短缝。     

模糊PID和Hopfield神经网络在矿井通风系统中的应用

针对传统的PID控制或者单一的模糊控制无法准确控制矿井通风系统风量的问题,提出了一种采用模糊PID调节器和Hopfield神经网络调节器对矿井通风机的转速、风门、风量进行控制的方法。该方法利用模糊控制器对PID参数进行实时修正,并结合Hopfield神经网络的联想记忆功能和反馈调节特性,实现矿井通风机风量的快速、稳定输出。仿真与实验结果表明,模糊PID调节器和Hopfield神经网络调节器可以准确控制矿井通风机的转速和风量,实现通风系统的稳定输出。     

一种新型矿井通风参数综合检测仪的研制

针对矿井通风安全技术管理中风阻测定方法繁杂、误差大、分析困难等问题,文章提出了一种新型便携式矿井通风参数综合检测仪的设计方案。该检测仪采用STM32F103VB芯片作为主控制器、采用电池供电方式,具有液晶屏、大容量存储器、键盘和通信接口,可采集矿井巷道压力、温度、湿度、风速、瓦斯浓度等参数,并可记录巷道编号、支护形式等巷道信息。试运行结果表明,该检测仪性能稳定、动作可靠、测量准确。     

通风网络区域划分算法与程序实现

通风网络风道之间的风量依从关系对于通风网络的合理性分析具有重要意义。对于任意复杂的通风网络系统,有时很难从图形上直接判断出任意2条风道之间的风量依从关系。文章提出了通风网络任意风道影响区和依赖区的概念,指出其可用于任意风道之间的风量依从关系的分析;介绍了通风网络各风道依赖区、影响区划分方法以及任意风道之间归属度和依赖度计算方法,并采用C#语言编制了程序;最后用实例验证了文中所论及算法的正确性。     

Local calibration of rigid pavement performance models using resampling methods

The performance prediction models in the Pavement-ME design software are nationally calibrated using in-service pavement material properties, pavement structure, climate and truck loadings, and performance data obtained from the Long-Term Pavement Performance programme. The nationally calibrated models may not perform well if the inputs and performance data used to calibrate those do not represent the local design and construction practices. Therefore, before implementing the new M-E design procedure, each state highway agency (SHA) should evaluate how well the nationally calibrated performance models predict the measured field performance. The local calibrations of the Pavement-ME performance models are recommended to improve the performance prediction capabilities to reflect the unique conditions and design practices. During the local calibration process, the traditional calibration techniques (split sampling) may not necessarily provide adequate results when limited number of pavement sections are available. Consequently, there is a need to employ statistical and resampling methodologies that are more efficient and robust for model calibrations given the data related challenges encountered by SHAs. The main objectives of the paper are to demonstrate the local calibration of rigid pavement performance models and compare the calibration results based on different resampling techniques. The bootstrap is a non-parametric and robust resampling technique for estimating standard errors and confidence intervals of a statistic. The main advantage of bootstrapping is that model parameters estimation is possible without making distribution assumptions. This paper presents the use of bootstrapping and jackknifing to locally calibrate the transverse cracking and IRI performance models for newly constructed and rehabilitated rigid pavements. The results of the calibration show that the standard error of estimate and bias are lower compared to the traditional sampling methods. In addition, the validation statistics are similar to that of the locally calibrated model, especially for the IRI model, which indicates robustness of the local model coefficients.