Hirokazu Kobayashi
,
Shogo Ito
,
Kenji Hara
,
Atsushi Fukuoka
催化学报
doi:10.1016/S1872-2067(16)62564-0
一种中孔硫酸化的、只含Br?nsted酸位的氧化锆-氧化硅催化剂可将甘油转化为丙烯醛,其产率和选择性分别为81%和82%.即使在低温(523 K)下,产物时空收率可高达9.0 mmol h–1 gcat–1.本催化剂的活性和选择性高于典型的硫酸化的ZrO2催化剂.氧化硅稀释了锆物种而使得催化剂酸性更温和,较大的孔径使得传质更快,因此催化剂性能提高.
关键词:
丙烯醛
,
甘油
,
中孔
,
硫酸化二氧化锆
ZHAO Dewen
,
XIE Yingjie
,
LIU Xianghua
,
WANG Guodong
钢铁研究学报(英文版)
Using the twin shear stress yield criterion, the surface integral of the coline vectors, and the integration depending on upper limit, Kobayashi′s threedimensional velocity field of rolling was analyzed and an analytical expression of rolling torque and single force was obtained. Through redoing the same experiment of rolling pure lead as Sims, the calculated results by the above expression were compared with those of Kobayashi and Sims formulae. The results show that the twin shear stress yield criterion is available for rolling analysis and the calculated results by the new formula are a little higher than those by Kobayashi and Sims ones if the reduction ratio is less than 30%.
关键词:
twin shear stress yield criterion;coline vector integral;threedimensional rolling;analytical solution
徐明海
工程热物理学报
本文分析对比了5种用于非结构化网格的扩散项的离散格式的精度和运算量.结果表明,除简单投影法外,其它方法的精度相差不大,但计算量差别较大.在此基础上,改进了Kobayashi的法向梯度法,克服了它对网格质量依赖较强和易于发散的缺点.总的结果表明在非结构化网格上提高扩散通量的计算精度仍然是一个值得继续研究的问题.
关键词:
非结构化网格
,
扩散项
,
离散格式
DENG Wei
,
ZHAO De-wen
钢铁研究学报(英文版)
A new linear integral method for bar hot rolling on roughing train was obtained. Above all, for inner deformation power, equivalent strain rate about Kobayashi’s three-dimensional velocity field was expressed by two-dimensional strain rate vector then inverted it into inner product and integrated term by term. During those processes, boundary equations and mean value theorem were introduced; but solution by definite integral was applied to integral procedure for friction and shear power. Then minimized the total upper bound power, and sequentially, analytical expressions of roll torque and separating force, and stress state factor were obtained. The calculated results by the expressions were compared with those of experimental values. The results show that this new linear integral method is available for analysis of bar rough rolling and the calculated results by the method are higher than those of experimental ones. However, the maximum error percentage between them is less than 10%.
关键词:
bar rough rolling;linear integral;strain rate vector;roll separating force
欧青立
,
徐林波
,
郭子叶
,
李娅
连铸
doi:10.3969/j.issn.1007-5461.2016.01.008
采用忆阻器替换分段线性电阻的方法,在Matsumoto,Chua和Kobayashi (MCK)提出的四阶混沌电路基础上,设计了一个含有忆阻器的五阶对称混沌电路,建立了五阶忆阻混沌电路的数学模型.采用常规动力学分析方法,分析了五阶忆阻混沌电路的平衡点集及其稳定性、Lyapunov指数.采用常规元器件,构建了五阶忆阻混沌电路的仿真模型,并进行了电路仿真实验.理论分析和仿真实验结果表明,设计的五阶忆阻混沌电路具有丰富的混沌行为,丰富了忆阻混沌电路的设计与应用.
关键词:
非线性光学
,
五阶忆阻混沌
,
动力学分析
,
忆阻器
,
混沌电路
