薄壁的

The formula can be used in approximate calculation of instable critical load of high pier in the design and construction.

本文利用能量原理的Ritz法，在对截面惯性矩变化作线性假定后，推导出变截面空心薄壁高墩失稳临界荷载近似计算公式，可用于设计施工中对高墩失稳临界荷载的近似计算。1中心压杆稳定理论及能量原理中心压杆的失稳问题是稳定问题中的一个最基本的问题。

Based on detailedly analyzing the application and development of plastic heat exchangers at home and abroad, one approach was advanced that by substituting plastic heat exchanger made of thin wall and canaliculus PTFE plastic tube for the metal heat exchanger of traditional lithium bromide absorption cooler.

本文在对国内外塑料换热器的应用、发展进行详尽分析的基础上，提出采用薄壁小管径聚四氟乙烯塑料管制成的塑料换热器代替传统的溴化锂吸收式制冷机中的金属换热器，制作一台塑料管溴化锂吸收式制冷机及其实验系统的课题。

The study reveals that the secondary xylem of 6 mangrove species of Sonneratia possesses the following characteristics:the diameter of vessel is small,the distribution frequency of vessel is high,the reperforating rate is high,the wall of vessel is thick,the wall of fibre is relatively thick and the wood parenchyma is short or sparse,whish is suitable with the environment.

应用光镜及扫描电镜对生长在热带、亚热带海岸潮间带的 6种海桑属红树植物的次生木质部进行了解剖学研究表明：海桑属 6种红树植物的次生木质部具有导管直径小，导管分布频率高，复孔率高，导管壁厚和纤维壁较厚且具次生加厚，木薄壁组织缺乏或稀少等与环境相适应的特点。

That if the process can produce much liquid phase during the sintering, and which can become into completely-crystal needle-shap or aborization or bar-shap calcium ferrite instead of glass in the cooling process; if the magnetite is interweaved by the caking into the melting corrosion structure, the granular structure or the eutectic structure instead of exiling in the massive isolation; if the mount of the poreis is little, and uniformitly distributing; if the grain is little; if the organizational structure is symmetrical, all of which can improve the quality of the sintering.

另外还归纳出有利于强度提高的工艺参数和操作制度。分析工业试验和水钢现行生产的矿物组成、结构表明，水钢烧结矿以他形晶磁铁矿为主，铁酸钙为主要的粘结相，多形成熔蚀结构、粒状结构和共晶结构，强度较高；而在台车边缘和表层，由于存在较严重边缘效应和点火温度较低，使该区域的烧结矿组织结构疏松，局部呈蜂窝状或薄壁大孔状，铁酸钙较少而硅酸二钙和玻璃质较多，形成骸晶状结构和磁铁矿连晶，强度较低，致使返矿升高。

The formulae for computing the sectional properties and mass properties of the main girders and the crossbeams were given. Then the dynamic characteristic analysis of two given rigid frame bridges were carried out using this model, the single beam model and the solid model respectively for comparison.

基于剪力柔性梁格理论提出了能够充分考虑薄壁箱梁的自由扭转刚度、约束扭转刚度和转动惯量的三梁式计算模型，推导了模型中各主梁截面特性和质量分布的计算公式，以及横梁刚度特性的计算方法。

Firstly, the leaf vascular bundle turned to single vascular bundle, and becoming concrescence, the mid-part presented the pith-like parenchyma tissue, the concrescence of the different needle in one bundle formed the typical structure of the short shoot.

首先针叶中的维管束全部转变为单维管束，进而针叶基部逐渐愈合，中央部位逐渐出现类似髓部的薄壁组织，不同针叶的维管束逐渐愈合，最终形成完全具备枝条的典型结构。

The flexible workpiece vibration modes are available for partitioning the distinct machining stages that denote the dynamic variation characteristics of the workpiece in the process and for selecting the high-order dynamic frequency modes that can produce the displacement at the tool-cutting position as the virtual vibration modes to predict the cutting stability.

根据薄壁零件的振型模态，划分表示工件在加工过程中动态特性变化的不同加工阶段、选取能够在刀具切削位置激起振动位移的高阶动态频响模型作为预测切削稳定性的有效振型。

Results show that random properties of parameters take more effect on the thin-walled box-girders.

计算结果表明，计算参数的随机性对薄壁结构的可靠指标有显著的影响，是工程设计中一个不可忽视的因素。

Based on the critical approach, a model for multiaxial fatigue life prediction was established by combining maximum shear strain and normal strain on the critical plane, and the effect of stress state under the multiaxial cyclic loading condition on the fatigue life was taken into account.

通过对薄壁圆管和缺口试样的高温多轴疲劳寿命特性分析，基于临界面方法提出了一个的多轴疲劳寿命预测模型，在考虑临界面上最大剪应变和正应变对多轴疲劳损伤贡献的同时，还引入了应力状态对多轴疲劳寿命的影响因素。

The number of spot-weld of thin-walled punched structures of automobile has important impacts on the automotive manufacturing cost.In order to reduce the cost,topological optimization of the spot-weld is becoming a hotspot.

汽车薄壁冲压件的焊点数量是汽车制造成本的决定性因素，为了降低成本，焊点的拓扑优化逐渐成为人们关注的热点。

It has been put forward that there exists single Ball point and double Ball points on the symmetrical connecting-rod curves of equilateral mechanisms.

从鲍尔点的形成原理出发，分析对称连杆曲线上鲍尔点的产生条件，提出等边机构的对称连杆曲线上有单鲍尔点和双鲍尔点。

The factory affiliated to the Group primarily manufactures multiple-purpose pincers, baking kits, knives, scissors, kitchenware, gardening tools and beauty care kits as well as other hardware tools, the annual production value of which reaches US$ 30 million dollars.

集团所属工厂主要生产多用钳、烤具、刀具、剪刀、厨具、花园工具、美容套等五金产品，年生产总值3000万美元，产品价廉物美、选料上乘、质量保证，深受国内外客户的青睐