Dynamic real‐time monitoring of chloroform in an indoor swimming pool air using open‐path Fourier transform infrared spectroscopy

This study used open‐path Fourier transform infrared (OP‐FTIR) spectroscopy to continuously assess the variation in chloroform concentrations in the air of an indoor swimming pool. Variables affecting the concentrations of chloroform in air were also monitored. The results showed that chloroform concentrations in air varied significantly during the time of operation of the swimming pool and that there were two peaks in chloroform concentration during the time of operation of the pool. The highest concentration was at 17:30, which is coincident with the time with the highest number of swimmers in the pool in a day. The swimmer load was one of the most important factors influencing the chloroform concentration in the air. When the number of swimmers surpassed 40, the concentrations of chloroform were on average 4.4 times higher than the concentration measured without swimmers in the pool. According to the results of this study, we suggest that those who swim regularly should avoid times with highest number of swimmers, in order to decrease the risk of exposure to high concentrations of chloroform. It is also recommended that an automatic mechanical ventilation system is installed to increase the ventilation rate during times of high swimmer load.     

Synthesis of the novel fluoride-containing organic silane

A fluoride-containing organic silane was synthesized by the reaction of N-ethyl-N-hydroxy-ethyl perfluorinated octyl sulfonamide (EHPOS), N-(β-aminoethyl)-γ-aminopropyl trimethoxy silane (ATS) and cis-butenedioic anhydride (CA). The experimental results show that the yield of product is up to 87% when the molar ratio of EHPOS: CA: ATS is 1: 1.05: 1.1. EHPOS and CA were maintained at 115 °C for 3 hours, then after cooling the reaction solution to 75 °C, ATS was added and reacted for another 3.5 hours at 145 °C. The structure of the product and thermal properties were characterized by Fourier transform infrared (FTIR) and thermogravimetric analysis (TGA), respectively. Results show that fluoride-containing organic silane has excellent thermal stability below 185 °C. Funded by the Military Defense Project (No. 200701HX03)     

Advanced thermal enhancement and management of LED packages

Thermal management of packages consists of external cooling mechanisms, heat dissipaters, and thermal interfaces. While keeping cooling condition constant, junction temperature of LEDs with higher thermal resistance increases more rapidly; hence the luminous efficiency decreases more obviously. This paper includes the discussion about the calculation methods of the lighting's heat transfer. The calculation process has been demonstrated by an example of cooling of LEDs lighting in this paper. In particular, the operation package heat transfer enhancement is required by most package manufacturers with a decrease of 20% ~ 30% of the thermal resistance over conventional package geometries.     

鱼的能量需要及对饲料能量的利用

文章分析了当前国内外鱼类能量测定的各种方法与差异,通过对己有实验数据分析发现,鱼类对饲料中碳水化合物的利用率较低,对蛋白质饲料的利用率较高.     

平面磨削颤振与表面波纹度研究

本文对平面磨削颤振的发生与发展进行了试验研究及理论探讨,分析了磨削工艺参数对磨削颤振的影响,并研究了表面波纹度与磨削颤振之间的内在联系.     

可控气氛热处理新气源——醇类低温催化裂解气氛

这是一种立足于煤,适合国情,可以加速推进我国可控气氛热处理的新气源.文章从理论上分析了甲醇何以能够在约300℃的低温下充分裂解,900℃炉温下能得到1%的碳势,更新了甲醇只是一种中碳势载气原料的传统概念.甲醇低温催化裂解机比进口的甲醇高温裂解机有许多优越性,文章从5个方面用生产实例证明了它在高碳钢淬火保护、薄层渗碳、碳氮共渗和复碳等工艺上所取得的可喜效果.利用催化剂的多种功能,还可以方便地将气氛碳势在0.2～1.3%之间准确地调变.文章提供了调变碳势的方法和参考规律.降低碳势以满足低碳钢退火保护和回火保护的需求;提高碳势则是一种有前景的渗碳气氛。     

CR／MMA接枝胶粘剂的研究

本文研究了反应温度、引发剂用量、单体用量及体系浓度对ＣＲ／ＭＭＡ接枝聚合反应的影响，运用正交设计总结出了最佳反应条件。     

工业锅炉主汽压力和汽包水位的自校正控制系统仿真研究

本文对工业锅炉主汽压力和汽包水位的控制,分别采用了自校正控制器控制,仿真试验表明,自校正控制器对于动态特性比较复杂的对象有很好的控制效果。     

单整定参数的简化CGPC控制器

本文阐述一种连续时间广义预报控制器(CGPC)的简化设计方法,这种简化设计将原来CGPC控制器的15项设计参数减少至两个,同时不失去原CGPC控制器的优良控制性能;与原CGPC控制器相比,这种简化的CGPC控制器具有无控制加权、无参考轨迹设计、无参数估计器、无预测起点相对时间T_1,自动设计N_v,N_u和C(s)的特点,狭义的设计参数只剩下仿真步长δ和预测终点相对时间T_2,其中T_2是唯一的现场整定参数。