柴油机精确实体模型的结构化网格建立与应用

利用逆向工程获得4B26柴油机的螺旋进气道,通过三维造型软件,建立该柴油机进气道—气门—气缸的精确实体模型。应用多块结构化网格的划分思想,借助ICEM—CFD软件,完成4B26柴油机整机的结构化六面体网格划分,建立了基于KIVA—3V程序的柴油机瞬态仿真模型。计算结果表明,所建网格能够满足KIVA—3V的计算要求,瞬态模型计算的缸内压力与试验值吻合较好,实现了KIVA—3V程序在复杂计算区域上的应用,拓展了程序的使用范围。     

EFFECTS OF OUABAIN AND DIGOXIN ON THE GENE EXPRESSION OFSODIUM PUMP α-SUBUNIT ISOFORM IN AORTIC SMOOTH MUSCLE OF RATS

Accumulating evidence indicates that endoge-nous ligands of the digitalis receptor may exist inthe mammalian body, which has recently been de-scribed to be indistinguishable from ouabainL1'2j.Endogenous ouabain (EO) might induce many cy-tobiological changes and play an important role inregulating water and sodium metabolism and vas-cular tone in the body["'J. Many studies haveshowed that EO content in both hypertensive pa-tients and hypertensive animals is much more thanthose of normal subje…     

白藜芦醇的免疫调节作用

目的　探讨白藜芦醇对免疫系统的调节作用。方法　通过建立免疫抑制模型鼠来观察不同剂量的白藜芦醇对机体免疫功能的影响。结果　不同剂量的白藜芦醇均能显著提高免疫抑制模型鼠的巨噬细胞吞噬率、血清半数溶血值、机体抗体形成细胞数量、淋巴细胞转化率及抑制小鼠耳片肿胀度即正常小鼠的Ⅳ型超敏反应。结论　白藜芦醇可对免疫功能低下和免疫缺陷小鼠发挥免疫调节作用 ,并可抑制正常小鼠的Ⅳ型超敏反应。     

A Simplified Approach to Analysis of High—Rise Frame Tube Structures

Based on finite element method and finite strip method, a simplified approach was presented to analyze high-rise frame tube structures. The generalized strip element is introduced and then the generalized stiffness matrices for beam and column-line are derived by using the displacement functions that describe the nodal displace-ments and displacement transforms. Furthermore, the formulas for the generalized stiffness matrix of generalized strip element and load arrays corresponding to the displacement parameters were developed. It is shown through a series of numerical computation that the nodal angular displacements at the same floor in a generalized strip element are approximately identical. A comparison of the finite element method and the finite strip method shows that the simolified approach not only is accurate, but also reduces the number of basic unknown quantities.     

三菱公司的铁道车辆用空气压缩机技术与产品

日本三菱公司在机车车辆用制动装置的技术研发中着重考虑了确保运输安全、稳定、小型轻量化,以及环保等方面的需求。介绍了该公司为铁道车辆用制动装置等精心研制的空气压缩机的特征、技术参数和应用效果。     

形形色色的微型收音机

随着微电子技术的发展,国外消费类电子产品日益向“薄、轻、短、小”的方向变化。国外流行的微型收音机,它们不仅设计精巧、造型奇特,而且很有实用价值,给人类的生活提供了种种方便,因此深受消费者青睐。     

对车体连接部噪声侵入部位采取降噪对策后效果的验证方法

介绍了降低车辆连接部噪声的试验方案,阐述了定置试验方法以及采取降噪对策后效果的验证、确认。     

汽车噪声测量的声场空间变换方法及其应用

降低汽车噪声的前提条件是准确确定噪声源位置及声强等参数,声场空间变换方法是确定噪声源位置的一种较好方法,阐述了声场空间变换的理论基础及基本原理,给出了应用实例,并对应用效果进行了分析。     

小型氦气制冷机技术

1.前言 超导电磁体除用于高能物理学和核聚变科学的实验设备外,近年来还广泛应用于工业设备和医用设备,并逐渐走向普及。随着超导电磁体的普及,价格低、可靠性高的氦气液化装置的需求量也日益增大。为进一步普及超导电磁体,必须降低其生产成本,使用户意识不到氦的存在,因此价格低、可靠性高且效率高的氦气液化