电火花线切割3B代码编程方法

3B代码程序是国产数控电火花线切割机床最常采用的格式之一,通过例举典型模具零件的加工,重点介绍直线和圆弧的3B代码编程方法。     

对男子110m栏技术要素的分析研究

跨栏技术的实效性、环节技术的熟练性、专业特点的经济性和反映这三个特性的几个技术如“直线性、节奏性、摆动腿技术、腿臂配合技术” ,构成了现代 110m跨栏跑技术的特点 ,使其更趋完善和合理。通过对 110m跨栏跑现代技术要素的分析 ,揭示了现代 110m跨栏跑的技术特点及理论依据 ,对男子 110m跨栏的教学、训练提供借鉴     

MEASUREMENT OF THE DIELECTRIC PROPERTIES OF BIOLOGICAL TISSUE

An open-ended coaxial line reflection method especially suitable for meas-uring the dielectric properties of biological tissue in vivo is described.This method offersthe advantage of not requiring any special preparation of the samples to be measured but aclose contact with the open end of a coaxial line.It is,therefore,very convenient to acquirea large number of measurement data in broad band rapidly.The method may also be usedto measure the properties of other substances.The measuring system consists of a networkanalyzer controlled by a microcomputer and calibrated by using ANA procedure to elimi-hate the influnce of error network introduced by the adapter,some connectors,etc.In or-der to reach higher accuracy,the iterative method is used to determine the parameters ofthe equivalent circuit.Measurements of permeativities of some living tissues have been per-formed in the frequency band of 0.5-2GHz.Compared with the results known in somepapers,the validity of this method has been confirmed.The difference in dielectric proper-ties between living and dead tissues,and the tissue permeativites(ε)versus frequency andduration of measurement after death have also been measured.     

Neuropsychological Assessment of First‐Year Architecture Students’ Visuospatial Abilities: Overview

First‐year architecture students are expected to utilise visuospatial abilities to generate/construct, retain, rotate and manipulate space mentally and physically through physical and digital representations. This study of 57 female and 23 male participants was conducted to investigate first‐year architecture students’ visuospatial abilities by means of the Beck Depression Inventory, Logical Reasoning Test and Judgment of Line Orientation (JLO) test. Participants’ sexes, cognitive development level, depression scale scores, university entrance exam results, vision disorders, physical competences, art training prior to university and error types were the study’s main parameters. The results showed that academic scores of the participants both to enrol in the program and complete the first‐year studio did not correlate with their JLO scores. Nondepressed participants performed better in JLO. Error analyses demonstrated that there is a concentration on certain items according to the test stimulus line positions, especially in females. Those who reported limited physical and visual competency made more mistakes in the same items. The study concludes that sex, depression, and individual differences in physical and visual competency, and art training, are significant variables for visuospatial performance. Judging visuospatial parameters through spatial design exercises is different from having proper methods and instruments to assess the achievements of the students regarding those abilities in architectural design education. It is important to map students’ visuospatial abilities individually from a developmental perspective. There is a strong need to develop 4D psychometric instrument to assess visuospatial abilities.     

圆钢矫直机轧辊曲面的设计

以轧辊曲面为研究对象,分别运用图解法和解析法求解轧辊曲面的接触线和曲面轮廓线,并可用计算机计算出结果或输出图形,以满足实际生产需要.     

单摆测重力加速度的误差问题

本文从物理理论和实验操作等几个方面比较详细地分析了用单摆测重力加速度的误差问题。     

混合CD-DY共轭梯度法

在CD方法和DY方法的基础上对求解无约束优化问题提出了一种混合的CD-DY共轭梯度法.在广义Wolfe线搜索下无需给定下降条件,即可证明混合方法的全局收敛性.初步试验表明新方法的数值效果优于CD方法和DY方法.     

裸子植物的幼苗类型及其进化关系

 裸子植物的幼苗可分为3个类型、8个亚型。即：1．苏铁型，包括苏铁亚型、银杏亚型、南洋杉亚型；2．松型，包括杉亚型，松亚型，麻黄亚型；3．买麻膝型，包括买麻滕亚型，百岁兰亚型。类型和亚型都有特征描述，并有一个检索表。文中首先讨论了种子的起源是多元的，因而裸子植物的起源也应是多元的，是前裸子植物不同类型平行进化的结果。 又根据裸子植物幼苗类型的形态特征，提出裸子植物有4条进化路线，即：苏铁路线，银杏路线，松柏路线和买麻滕路线。还讨论幼苗类型之间的进化关系，认为除买麻滕型幼苗因其形态特殊有自己独特的发展路线外，总的趋势是由留土萌发向出土萌发发展。     

基于土地利用冲突识别与协调的“三线”划定方法研究——以常州市金坛区为例

在经济发展新常态和建设“美丽中国”的要求下,科学合理地划定基本农田保护红线、城市开发边界和生态保护红线（“三线”）对统筹协调“生产-生活-生态”空间、高效配置土地资源、优化城市景观格局等具有积极意义。本文在对“三线”内涵解析的基础上,提出了“三线”协同划定的分析框架和协调策略,选取江苏省常州市金坛区为案例区,通过构建“生态-耕作-建设”三种利益导向的土地适宜性评价体系,分析了不同目标导向下各类土地利用适宜性程度,综合各适宜性评价结果识别土地利用冲突区,基于生态优先、集中紧凑、邻域和谐和空间识别的原则,对各类冲突区进行耦合协调,以期为“三线”划定提供新思路。研究结果表明：金坛区的生态保护红线范围主要包括西部的茅山片区、北部的天荒湖湿地以及钱资湖、长荡湖等区域,总面积260.63km²;基本农田主要分布在茅山片区及低山丘陵的东侧,中部冲积湖积圩田平原和东部的高亢平原,总面积303.57km²;城市开发边界圈定了中心城区可扩张的最大范围,总面积69.43km²。     

诺贝尔科学奖获得者的教育背景分析及其启迪

诺贝尔科学奖是世界公认的和最具权威的最高荣誉奖,但是中国大陆的科学家至今还与诺贝尔科学奖无缘.教育与科学关系最为密切,通过研究外国著名大学教育、研究生教育、创新教育、实验教育和家庭教育对诺贝尔科学奖人才产生的重要作用,旨在加强我国人才教育和高水平大学建设,为中国科学家获得诺贝尔科学奖提供有益启迪和借鉴.