Combustion Reactivity of Rice Husk：An Experimantal and Numerical Investigation

The combustion reactivity of rice husk from New South Wales,ustralia was measured by heating cubical baskets in controlled environment and monitoring the centre temperature.Frank-Kamenetskii‘s ignition theory was used to calculate the activation energy,Results agreed well with tests on other cellulosic materials,Numerical simulations of temperature changes were carried out,using a special technique to deal with non-linearities in the heat conduction equation.The numerical Results indicate that the time factor should be taken into account when evaluating self-combustion risks.     

循环流化床锅炉的飞灰含碳量问题

循环流化床锅炉的飞灰含碳量问题近年来受到关注。对实际运行的多台燃烧各种燃料的220t／h锅炉的飞灰样品测定表明：飞灰的含碳量具有明显的不均匀性。分析了煤质、分离器及运行条件对飞灰含碳量的影响。结果表明：循环流化床锅炉燃烧过程中焦炭反应性逐渐下降;焦炭燃烧过程中发生的爆裂、磨损、失活等行为与煤种有关,对循环流化床锅炉飞灰碳燃尽有很大影响。气固混和不均匀是导致较高的飞灰含碳量的原因之一。图7表2参13     

高火山灰活性煅烧煤矸石添加量对水泥抗压强度的影响

为研究高火山灰活性下煤矸石添加量对水泥抗压强度影响,以龙岩翠屏山煤矿煤矸石为研究对象,分析了温度对煤矸石活性的影响以及煤矸石添加量对水泥强度的影响。结果表明:随着煅烧温度的增大,煤矸石烧失量在逐渐增大,烧失量与煅烧温度呈幂函数关系;随着煅烧温度的增大,煤矸石活性呈现先增大后减小的规律,煅烧煤矸石吸钙量与温度成二次多项式关系,推断实验煤矸石的煅烧最佳温度为750 ℃;随着煤矸石添加量的增加,水泥单轴抗压强度呈下降趋势,试件的抗压强度与煤矸石添加量成指数关系;随着龄期的增大,添加煤矸石的试件强度具有增长的趋势。研究结果对确定煤矸石添加量提供了理论依据,对指导煤矸石在凝胶材料中应用具有重要意义。     

基于MCNP程序的海洋核动力平台堆芯核设计校核计算研究

海洋核动力平台是小型核反应堆与船舶工程技术的有机结合,具有机动性好、一次性装料运行周期长、功率密度大、运行成本低、节能环保等特点。本文采用蒙特卡罗粒子输运程序(MCNP),建立海洋核动力平台反应堆堆芯几何模型,计算该反应堆首循环初始装料冷态、常压下的堆芯反应性和控制棒价值,并与核设计计算结果进行对比。结果表明:MCNP程序适用于海洋核动力平台反应堆堆芯核设计校核计算,并可与核设计值互相验证。     

Introduction.

This article introduces this special issue of Health Psychology. Its purpose is to summarize recent findings on the influence of race on autonomic nervous system reactivity. Many but not all of the studies in this special issue were funded by a National Heart, Lung, and Blood Institute initiative. The studies reported herein, as well as those published recently in other journals (for a review, see Anderson 1989), represent perhaps the first generation of studies that have explored the reactivity model in Blacks. As such, they provide an empirical foundation on which future studies may build. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

丙烯腈与N-乙烯基吡咯烷酮共聚体系对单体竞聚率的影响

利用Kelen—Tudos方法测算丙烯腈(AN)与N—乙烯基吡咯烷酮(NVP)自由基共聚合单体竞聚率，研究了不同反应体系对单体竞聚率的影响。结果发现：在水相悬浮聚合体系中，转化率小于18％时，两单体的竞聚率同DMS0均相溶液聚合结果相近；转化率较大时，同容液聚合结果偏差较大。H2O／DMS0混合溶剂悬浮聚合时，当水含量超过60％(质量比)后，单体竞聚率向水相悬浮聚合结果靠近。溶剂的极性增大，rAN与rNVP值均减小。随反应温度升高，共聚反应向理想共聚方向进行。     

Photocrosslinkable copolymers based on 4‐acryloyloxyphenyl‐3′‐chlorostyryl ketone and methyl methacrylate: synthesis,comonomer reactivity ratios and UV photosensitivity

A new photosensitive acrylate monomer having a pendant chlorocinnamoyl moiety (APCSK) was copolymerized with methyl methacrylate (MMA) in different feed compositions in ethyl acetate solution at 70°C using benzoyl peroxide as a free‐radical initiator. The newly synthesized copolymers were characterized by FTIR, ¹H and ¹³C nuclear magnetic resonance (NMR) spectral techniques, as well as by size‐exclusion chromatography. Their thermal behaviour was assessed by thermogravimetric analysis in air and differential scanning calorimetry under nitrogen atmosphere. The copolymers exhibit no phase separation since there is only one glass transition temperature (T_g) value in the region of copolymer composition studied. The reactivity ratios of the comonomers were calculated by adopting linearization methods such as the Fineman–Ross (F‐R), Kelen–Tudos (K‐T) and extended Kelen–Tudos (ExtK‐T) methods, and by a non‐linear error‐in‐variables model method (EVM) using a computer program (RREVM). The results suggest that MMA is more reactive than APCSK and that their copolymerization leads to the formation of random copolymers. The photosensitivity of the copolymer samples was studied in solution as well as in thin films through UV irradiation. The influence of different factors, including solvent nature, concentration, temperature, photosensitizer and copolymer composition, on the rate of photocrosslinking of the photoreactive copolymers was investigated for effective industrial application of these polymers as negative photoresists. Copyright © 2004 Society of Chemical Industry     

在轻水堆上用模拟机落棒法测量反应性时一种消除空间效应的方法

推出一种以实验为基础，引入理论计算空间通量畸变因子Ｋ的修正公式来消除模拟机落棒法测量反应性空间效应的方法。用两个实例验证了该方法的效果；与脉冲中子源法结果作了比较，符合很好。该修正公式用微机输入参数作在线运算，将使落棒法在保持原有优点的前提下获得满足工程需要的精度。还列举两种典型的Ｋ因子平面分布图来说明其分布的规律，指出寻找到Ｋ在０８至１２之间区域内放置探测器，可得到一次落棒小于±３％的实测精度，而不需作任何修正。