EFFECT OF PORE DIFFUSION ON DEACTIVATING RATES OF SECOND ORDER REACTION

The research and development of catalysts, the design and operation of catalytic reactors are complicated by the phenomenon of catalyst deactivation which is affected by various factors. In this paper, the effect of internal mass transfer resistance in the second order catalytic reaction system of uniform independent deactivation on both reaction and deactivation rates of straight cylindrical pore model has been discussed. In addition, the quantitative relations between effectiveness factor and Thiele modulus in second order reaction and first order deactivation system have been correlated     

Particle velocity and solids circulation rate in a jet-spouted bed

Radial distribution of particle velocities, solids circulation rate and radial variation in bed voidage in a jet-spouted bed were investigated in a 0.2 m diameter conical-cylindrical column. The upward particle velocity is strongly dependent on gas velocity and its radial profile is the Gaussian. The solids circulation rates are of the same order of magnitude as those in a conventional spouted bed and are proportional to the gas velocity. Estimation of the variation in bed voidage in the radial direction revealed that the annulus voidage of about 0.90 was greater than the spout voidage of around 0.70. This tendency is contrary to that in a conventional spouted bed.     

异辛酸合成液的气相色谱分析

建立了异辛酸合成过程中异辛醇、异辛酸和酯的气相色谱分析方法。以 10 %改性聚乙二醇 2 0M为固定液 ,苯乙酮为内标物 ,氢火焰离子化检测器 ,内标法定量分析异辛酸。实验结果表明 ,该方法准确可靠 ,测得异辛酸的相对重量校正因子 1.30 5 ,相对误差小于 2 .0 %。同时通过与化学法对照结果显示 ,合成液用内标法测定较好 ,而精产品用带校正因子的归一化法测定较好。     

工业循环冷却水用BC－653杀生剂的抗菌性能测定

本文对ＢＣ－６５３杀生剂进行了室内抗菌实验，着重阐述了投药量对杀菌率的影响。结果显示该杀生剂与国外同类产品杀菌力基本一致。     

幂律流体三维脉动流场数值模拟

利用ANSYS软件，模拟了振动诱导单螺杆挤出机熔体输送段中非牛顿幂律流体的三维脉动流场，得到了三维脉动流场的瞬时速度分布及螺槽中物料的流动轨迹。结果表明，在脉动流场作用下，非牛顿流体的瞬时速度响应与在驱动壁面上所施加的正弦形式的脉动驱动形式不同，横螺槽方向的环流中心位置受幂律指数影响，且发生周期性改变。振动的引入使得在相同的时间内，物料的流动路程增加，且可增大物料的平均停留时间，有利于改善混合效果。     

2.5万t/a离子膜烧碱技改项目国产自然循环复极槽工程概况

介绍了在2．5万t／a离子膜烧碱技改项目中采用国产自然循环复极槽及其配套装置的设计依据及运行情况，认为国产离子膜电解槽运行情况良好，但尚需完善。     

浸没循环撞击流反应器制备牙膏用磷酸氢钙

采用浸没循环撞击流反应器（SCISR），以焦磷酸钠和磷酸三镁为稳定剂，以磷钙液和石灰乳为原料，通过中和反应法制备出了平均粒度10μm的牙膏用微细磷酸氢钙；探讨了反应温度、熟化时间、反应器装填系数、反应终点pH、磷钙液质量浓度等对产品质量的影响。确定了最优操作条件：磷钙液质量浓度1．17～1．19kg／m^3，反应温度42℃，熟化时间2h，反应终点pH6．3，反应器装填系数0．75。得到产品符合HG3257—2001标准。     

Treatment of methanol wastewater with two-stage and two-phase anaerobic process

The two-stage and two-phase anaerobic process (TSTP) composed of hydrolytic acidification reactor,first-order and second-order external circulation anaerobic reactors (EC) was taken to treat methanol wastewater. Test results show that TSTP process is quick start-up in 51 d, and the maximum VFA of hydrolytic acidification reactor effluent reaches 876 mg/L. Under the condition of volume loading of 6.56 kgCOD/m3·d, COD removal rate of the first-order EC reactor is about 85%, and under the condition of volume loading of 1.02 kgCOD/m3·d, COD removal rate of the second-order EC reactor is about 50%. When the inflow COD of TSTP process is between 7000-11000 mg/L, its effluent COD is lower than 600 mg/L. In the biological conversion process of methanol into methane,the production of acetic acids as an intermediate product can be ignored and the direct production of methane from methanol is predominant.     

内部审计审计风险模型的探讨

全面风险管理理念已经兴起并形成了全面风险管理模式。全面风险管理模式有五个方面的特征,需要新的审计管理理论加以适应,这其中就包括了新的审计风险模型。新的审计风险模型结合全面风险管理理论和风险导向审计理论,侧重从内部审计的角度进行考虑,认为审计风险=企业总体风险中重大错报风险×检查风险。该模型能适应新形势下的审计要求,特别适用于内部审计部门。     

北太平洋涛动研究

北太平洋涛动是北半球大气中一个显著的、南北向跷跷板式的低频振荡,其演变不仅直接影响北太平洋附近地区的天气和气候,甚至对整个北半球的环流异常、持续以及气候突变都有重要影响.文章综述了北太平洋涛动的时间演变特征、区域变化特征、常用计算方法、北太平洋涛动指数的定义以及它们对天气气候的影响,阐述了需要进一步解决的一些问题,指出了目前关于NPO的研究尚处于初级阶段,对NPO的研究还可以借鉴其他涛动中较为成熟的研究方式和方法.