Numerical methods for integrating chemical kinetic rate equations

In this paper we present a numerical method which is suitable for the integration of chemical rate equations. These equations are normally extremely stiff due to large differences in the kinetic rate coefficients. The method takes advantage of the fact that the Jacobian matrix is readily obtainable for this type of problem. Stability analysis will also be discussed in a general framework.     

受基坑支撑影响的地下室劲性钢结构施工技术

高层建筑地下室常具有支撑密集、施工空间狭小等特点,常导致劲性钢结构与土建施工相互影响,影响施工效率与安装精度。为此,研究一种适合于受基坑支撑影响的地下室劲性钢结构施工技术,采用自制的微调定位措施,提高悬空地脚螺栓的安装精度;另外,通过优化劲性钢柱吊装方法,提高施工效率与安装精度,解决受基坑支撑影响下的劲性钢柱安装问题。并采用全站仪与水准仪进行监测,最大偏差均控制在3mm以内,取得了较好的效果。     

长节段钢管拱肋与系梁劲性骨架整体安装技术

对常州戚墅堰大桥的长节段钢管拱肋与系梁劲性骨架整体安装技术进行了介绍,指出施工过程中的大构件空间定位技术、大阶段拱肋安装变形控制技术、拱肋简支状态下水平力控制技术等具有创新性,在类似桥梁施工中可以推广应用。     

乌石北江大桥主塔施工技术

阐述了乌石北江大桥主塔施工的方案,对劲性骨架施工、索导管安装及调整、塔柱爬模系统及预应力施工等关键技术的施工要点进行了详细介绍,以确保工程的质量,实现主塔的成功封顶。     

一种适用于分布式发电系统的显式一隐式混合积分算法

针对分布式发电系统的典型特征,提出了一种适用于分布式发电系统的显式…隐式混合积分算法。分布式发电系统中电力电子元件具有较快的动态特性,而分布式电源本身如燃料电池、风机、微型燃气轮机、蓄电池等动态响应较慢,根据这一特性设计了算法的划分原则,针对快动态电力电子元件采用隐式积分算法,针对慢动态分布式电源采用显式积分算法,同时...     

硬盒机节约型内卡纸供给装置

介绍了HLP、YB41和YB43硬盒香烟包装机的节约型内卡纸供纸装置的主要结构、传动原理和改进内卡纸尺寸的主要措施，以及该产品所具有的节约降耗带来的经济效益和社会效益。     

国家大剧院H型钢劲性柱施工

结合国家大剧院工程的施工过程,针对H型钢劲性柱的加工、制作、安装及混凝土施工工艺进行分析和探讨。     

Numerical simulation of the deflagration to detonation transition

The present work is focused on the numerical simulation of the deflagration to detonation transition. The Euler equations expressed for a time-dependent, compressible, and one-dimensional flow with finite-rate kinetics are solved with adaptive mesh refinement. Because of the problem stiffness, a time-step splitting method is used to couple the conservation equations and the chemical kinetics equations. The calculated length of the deflagration to detonation transition in H₂-O₂ and CH₄-O₂ mixtures in a confined domain and the time evolution of detonation are in good agreement with the theoretical values of constant volume explosions and Chapman-Jouguet conditions. The length of the transitional region is compared with experimental findings for a range of initial fuel concentrations, which shows that the model predicts the tendencies qualitatively well but yields significant quantitative deviations.__________Translated from Fizika Goreniya i Vzryva, Vol. 41, No. 2, pp. 108–115, March–April, 2005.     

Numerical Simulation of Differential Systems Displaying Rapidly Oscillating Solutions

The aim of this article is to describe an approximation procedure for stiff differential equations producing highly oscillating solutions. For the sake of simplicity the presentation is restricted to ordinary differential equations. The procedure and the general approximation results are presented. Then the general results are applied to a number of simple explicit systems, for which numerical simulations of the exact and approximate solutions are performed and compared.     

GDX2包装机新型硬盒烟内卡纸供给系统

介绍了GDX2包装机新型硬盒烟内卡纸供给系统的主要结构和工作原理 ,通过对决定内卡纸长度尺寸的零件及相关装配零件尺寸的改进 ,以达到缩短内卡纸长度。产生可观的经济效益和社会效益