高频低造型变压器绕组的折叠式制作方法

比较了两种高频低造型变压器绕组的折叠式制作方法,即"z"字形法和"5/6匝"法。实验表明,后者与前者相比,不仅使绕组对磁心窗口面积的利用率和生产效率有显著的提高,而且减少了绕组的损耗和变压器的漏感,提高了导体材料的利用率,从而降低了产品成本。

高频低造型电源变压器的计算机辅助设计

介绍了高频低造型(High-Frequency and Low-Profile)电源变压器的计算机辅助设计。当给定设计参数诸如变换器拓扑、输入输出电压、输出功率、变压器效率等后,此程序便会自动搜索满足设计要求的体积最小的变压器。设计者可根据具体要求,调整设计参数,以达到最为满意的设计结果。

高频低造型磁性元件设计

概述了高频开关电源当中的低造型磁性元件的发展现状,具体介绍了几种主要磁性材料的特点,并重点对几种新型磁性元件的磁心和绕组结构设计作了比较。

高频低造型变压器绕组导体的最佳厚度

利用麦克斯韦电磁场方程求得高频低造型变压器绕组导体在一定频率下的最佳厚度,即铜损值最小时的导体厚度。此结果与利用美国 Ansoft 公司的电磁场仿真软件算得的结果相一致。

高频低造型电源变压器的设计与应用

探讨了高频低造型电源变压器设计的有关问题，给出了平板式绕组的设计制作方法。该方法能自动串连绕组各层导体从而解决了绕组各层导体之间的连线问题，避免了焊接，大大提高了器件的可靠性和绕组对磁心窗口的利用率。实验结果用这种方法制作的变压器漏感小、效率高、特别适合用于分布式高功率的七关电源模块当中，文中还给出了高频低造型电源变压器的计算机辅助设计方法，这不仅使得设计过程更灵活、快捷、也使得设计结果更可靠。

高频低造型电源变压器的设计与应用

本文探讨了高频低造型电源变压器设计的有关问题,给出了平板式绕组的设计制作方法。该方法能自动串连绕组各层导体,从而解决了绕组各层导体之间的连线问题,避免了焊接,大大提高了器件的可靠性和绕组对磁芯窗口的利用率。实验结果表明,用这种方法制作的变压器漏感小、效率高,特别适合用于分布式高功率密度的开关电源模块中。文中还给出了高频低造型电源变压器的计算机辅助设计,这不仅使得设计过程更灵活、快捷,也使得设计结果更可靠。

低风阻分体式电动汽车造型设计

分体式造型是汽车外形设计的全新领域,在造型方面具有突破性的意义,但突出的问题之一是风阻往往比普通汽车更高,因此如何做到低阻化是一个新的课题.以A级车为参考车型级别,建立了分体式低风阻基本造型,并考虑了人机空间等基本实用性因素.之后通过造型不断细化与空气动力学仿真迭代方法,最终获得了风格鲜明的分体式造型,并使其风阻系数C_D仅为0.224 9,达到了预期目标,具有应用与推广价值.

基于低风阻的电动汽车造型设计

分析了当代电动车造型整体格局,确定了目标车型的基本参数.基于最小阻力体气动研究,将低阻生物作为形态仿生对象,完成了低阻车体设计.通过与传统车的对比研究,确定了整车的造型风格.之后对车头、车轮等各部位依次作了造型与气动优化,完成了整车设计.整个过程采用了气动、散热、人机布局、仿生等多元素耦合的研究方法,最终得到了一款全新低阻电动汽车造型,制作了1:1模型.经风洞试验风阻系数C_D为0.193,明显优于0.238的预估目标值.

服装制版中的二次成型

在服装制版过程中有些特殊结构无法一次成型,有些过程复杂,费时费工,需分阶段进行完成。这种分阶段完成服装结构造型的方式,笔者称之为＂二次成型＂、＂三次成型＂或＂多次成型＂。有效的利用这些分阶段完成的方法,可以降低造型难度,提高工作效率和制版速度。

Mechanical performance of the mixed post-installed connection in low-strength concrete

Due to inadequate bearing capacity of the chemically-planted steel bar in low-strength concrete, a new mixed post-installed connection is proposed using small diameter anchoring steel bars and grouting materials together to anchor the main steel bar. To investigate the feasibility of the proposed post-installed connections, a series of pull-out tests with different anchors were conducted for comparison,including fully adhesive anchors, partially adhesive anchors,grouting material anchoring connection and the new mixed post-installed connection. The experimental results of the single steel bar pull-out test show that the mixed post-installed connection can effectively enhance the bearing capacity of post-installed steel bars in low-strength concrete. The bearing capacity is increased by nearly two times with no cone-type concrete failure compared with the fully adhesive anchor. The results show that adopting the new mixed post-installed connection can ensure that joint performance meets the requirements if the space dimension is available.

20世纪西方流行时尚中低腰造型特点分析

本文以20世纪低腰造型流行的20年代、六七十年代和90年代的社会人文和流行时尚为背景,从低腰造型的位置/形态、与人体腰部结构的关系、着装感等方面对其造型特点进行分析和比较,为低腰的合理化、个性化的结构设计提供依据和参考。

Low Cost and Reusability of Launch Vehicle

This paper analyzes the launch price of the launch vehicles, domestic and abroad, studies the status and trend of the low cost launch vehicles, and introduces two measures to reduce the cost by means of evolved and disruptive technologies, utilizing the concept of low cost manufacturing and operating modes as well. This paper also analyzes the launch strategies for small satellites such as piggyback, networking launch, and single launch with a small launch vehicle(SLV). Finally, the development trend of reusable launch vehicles is discussed as well as the development prospects for China's reusable launch vehicle.

Analysis of Shape and General Arrangement for a UUV

The construction and shape of UUVs are described in the paper. UUV design is the shape of the overall design of unmanned underwater vehicle should first be resolved UUV underwater vehicle directly affects the shape of the resistance and noise, which is related to energy, payload, maneuverability and concealment UUV problem The main characteristic and parameter tables for foreign torpedo shape, fiat shape and anomalous shape are also given in the paper. The general layout of typical foreign UUVs is analyzed in detail. And the total layout figure and interior constructive figure are introduced. Torpedo-type because of its good water power and low noise, no one has been the main form of underwater vehicle-like, and many designers are now highly favored because of its stable performance, anti-environmental interference capability. Other irregular shapes designed primarily for the completion of a specific task, according to the specific environment and mission requirements. According to comparing and summarizing, some suggestions and conclusions are oresented.

3D numerical simulation of high pressure squeezing process with revised Drucker-Prager/Cap model

In order to investigate the sand mold strength after the aeration sand filling-high pressure squeeze moldingprocess,a tree-dimentional(3D)numerical simulation was introduced.The commercial finite element method(FEM)software ABAQUScombined with a revised Drucker-Prager/Cap model was used to simulate the squeeze compaction process.Additionally,the sand bulk density after the aeration sand filling process was tested by a specially designed experiment,which divided the whole sand bulk in the molding chamber into5x9regions and it was used as the input to simulate the squeeze process.During the simulation process,the uniform modeling simulation and the patition modeling simulation methods were used a d the3D numercal simulation results were compared with correlative benchmark testings.From the3D numerica simulation results,it can be concluded that the uniform sand bulk density distribution can obtain a high quality sandmold and the revised Drncker-Pager/Cap model is suitable for handling the situation with the complex paaern.The3D numerical simulation results can predict well the sand mold strength distribution and can be used as guidelines for the production practice.