螺旋伞齿轮精锻工艺及发展趋势的研究

当前,代表各国机械制造发展程度的是齿轮精锻工艺的水平,提升锻造工艺水平可以促进中国机械工业更好更快发展,从而减少与世界顶尖技术的距离。并且能够更大程度上减少对资源的消耗和材料的浪费,给机械工业减少成本的消耗。因而文章从我国螺旋齿轮精锻研究概况、及其所面临的问题以及研究方法等几方面入手研究螺旋伞齿轮的精锻工艺,并且展望了该技术的未来趋势。     

双联齿轮的毛坯件制造分析

双联齿轮就是两个齿轮连成一体,这种双联齿轮在轮系中(变速器)被称为滑移齿轮,一般用于变速箱中主要起换档调速作用。双联齿轮本身的制造精度,对整个机器的工作性能、承载能力及使用寿命都有很大的影响。文章研究双联齿轮加工毛坯件的制造形式。     

Annual weather variability and its influence on the population dynamics of Calanus finmarchicus

The reaction of the population of Calanus finmarchicus to relatively extreme annual cycles of weather in the North Sea was investigated by one-dimensional model simulations. A population dynamics model for C. finmarchicus was coupled with a physical and a biological upper-layer model for phosphate, phytoplankton and detritus to simulate the development of the successive stages of C. finmarchicus. Observed annual weather cycles were used to drive the physical water column model, the results of which were then input to the plankton model. The simulations yielded the temporal development of all stages of C. finmarchicus over an annual cycle in terms of numbers and weights. Compared with the results reported for 1984 by Carlotti and Radach (1996; Limnol . Oceanogr . 41: 522–539), it appears that the temporal range for the occurrence of the peak concentration of C. finmarchicus may be 2 weeks in the northern North Sea. The simulated variability is in accordance with observations. Years with more continuous primary production such as the year 1984, which was cloudy and windy during the summer, may then provide the optimum conditions with respect to producing an abundance of zooplankton during the following year.     

Calcification of intervertebral discs in the dachshund. A radiographic study of 327 young dogs.

The vertebral columns of 327 clinically normal, 12 to 18 months old dachshunds, were x-rayed. This sample represented 16.1% of all dachshunds registered with the Norwegian Kennel Club in the period 1986-1988. Calcified intervertebral discs were identified in 79 (24.2%) of the dogs and the number of calcified discs in each individual varied from 1 to 11 with a mean of 2.3. Calcified discs were estimated to occur in 23.5% of Norwegian dachshunds. The occurrence of calcified discs in standard-sized dachshunds was higher in the wirehaired variety (27.1%) than in the smoothcoated (16.4%) or longhaired (9.1%) varieties. However, within the longhaired variety the occurrence was higher in dwarfs and kaninchens (36.0%) than in standard-sized dachshunds (9.1%). Calcification was identified in all cervical, thoracic and lumbar intervertebral discs other than T1-2, and was found to be most frequent in the caudal thoracic vertebral column.     

计算刚架的矩阵迭代法

本文在迭代法基础上推导出矩阵迭代法的计算公式。用以编制程序,可节省容量,尤其适用于袖珍计算机。     

论高校社科学报特色栏目的策划与建设

分析了高校社科学报目前存在的诸多问题:一是数量多,刊名相似;二是特色趋同,影响小;三是办刊模式陈旧,市场意识缺乏。认为高校社科学报在市场竞争中生存下去的手段是开办特色栏目,并指出设置特色栏目的方法:找准特色,开发作者群,选择好学术带头人。     

作物育种品系试验四种分析方法比较

用水稻、小麦和大豆的8个三重复品系试验的产量结果, 进行了作物育种品系试验的三种分析方法与随机完全区组分析(RB)的比较. 此三种分析方法分别是, 行列区组分析(RC)、行列区组及近邻小区分析(RCN)和行列区组及以小区丛数为协变量的协方差近邻分析(COV). 结果表明, 以误差均方作为相对效率指标, RC、 RCN、 COV相对于RB的平     

Determination of Load Share between Gear Teeth with Contact Finite Element Method

The determination of load share between teeth is a complex problem in gear strength calculation. On the basis of contact finite element method this paper considers the production-assembly error as initial gap to get the finite element model which meets load share between teeth in gear meshing. Through calculating and comparing the result with that from ISO formula to get the load share between teeth which meets the requirements in actual usage.     

Mothematical Model for Planing of Precise and Hardened Gear

In this paper, the mathematical model for gear planing of precise and hardened gear is established. The computational charts and results for the tooth edge height,cutter edge contact length and cutter area are given out to improve the present planing technique.     

THE PRINCIPLE AND TECHNIQUE FOR GEAR PLANING BY DISCONTINUOUS GENERATING

The principle of gear planing by discontinuous generating is introduced and two kinds of techniques are presented based on this principle. Examples are given to show that both the accuracy and efficiency of the new techniques are higher and the cost is lower that those of gear hobbing and gear shaping.