Results 1 to 10 of about 331 (103)

Research on the axial force-slip characteristics of permanent magnetic eddy current Frictional torque limiter [PDF]

open access: yes, 2023
In view of the current situation of short life and poor reliability of the overload protection device of friction moment limiter in coal mine machinery, a new high-power fast breaking permanent magnet eddy current friction Moment limiter (PMEFTL) is ...
Hong ZHANG, Yuting WANG
core   +1 more source

The influence of the electrical boundary condition on domain structures and electrocaloric effect of PbTiO3 nanostructures [PDF]

open access: yes, 2016
本文在基于金兹堡—朗道—德文希尔唯象理论的相场法理论下,应用有限差分方法及四阶龙格—库塔法数值求解,研究不同电学边界条件对铁电纳米点畴结构演化和热电温度效应的影响。本文所用的中间电学边界条件,可以用来表示表面电极与纳米点之间的黏合情况及电极对表面电荷的补偿情况,进而说明退极化电场和退极化电能对系统自由能的影响,不同以往的对退极化能进行权重处理,具有实际的物理意义。 当电学参数λ0为0时,中间电学边界可以退化为开路电学边界条件;当λ0趋向无穷大时,对应于短路电学边界条件,即表面电荷可充分补偿。λ0的值越大,
陈志英
core   +1 more source

Study on Remove of Free-Form Surface Structure by Magnetic Polishing [PDF]

open access: yes, 2017
磁性抛光因柔性工具的工件表面适应性高而具有较好的应用潜力。自行设计抛光工具头,制备磁性抛光体,搭建试验平台,并对不锈钢平面工件进行定点抛光试验,平均去除效率为0.231μm/10min,且工件表面质量得到了很大的改善,验证了该磁性抛光方法的可行性。继而对两种自由曲面结构工件进行抛光:一是采用工具头水平移动式、工具头等高线移动式两种不同的抛光进给运动方式对不同曲率的不锈钢工件进行抛光去除试验,试验证明:两种抛光方式对每个曲率的轮廓均有去除能力,去除量在0.14~1.33μm之间 ...
林龙侨, 王振忠, 陈世平
core   +1 more source

物理学的历史负担 = Altlasten der Physik [PDF]

open access: yes, 2023
人们通常沿科学发展的路径来学习物理。这是一条曲折的路径。在这条路径中,有许多错误的概念、多余的名称和过时的方法。在这本书中,我们用了200多篇文章的篇幅逐一分析了这些错误。每篇文章都有相同的结构:1.主题,2.负担,3.历史,4.建议。这些文章已经发表在一些期刊中。因此 ...
Herrmann, Friedrich, Job, Georg
core   +2 more sources

Optimized Copper Distribution and Enhanced Coercivity in PrO2‐Doped Sm2Co17‐Type Magnets

open access: yesRare Metals, Volume 45, Issue 1, January 2026.
ABSTRACT A rational design of Cu distribution is crucial for achieving optimal magnetic properties in Sm2Co17‐type magnets. In this study, nanostructured PrO2 powders were employed to induce Cu redistribution at grain boundaries while preserving the cellular microstructure. The corresponding coercivity (Hcj), remanence (Br), and maximum energy product (
Qi‐Qi Yang   +5 more
wiley   +1 more source

Paleogeographic reconstruction of the North China Craton in the supercontinent Nuna/Columbia: paleomagnetic and geological constraints [PDF]

open access: yes, 2019
The North China Craton has abundant Precambrian geological records, but its positions in the two supercontinents are still controversial. Detailed geochronological, geochemical, rock magnetic and paleomagnetic analyses have been carried out.
Wang, Chong
core  

近代科学得以产生的社会根源 [PDF]

open access: yes, 2014
近代科学兴起于16-17世纪的欧洲,究其社会根源错综复杂。文艺复兴、宗教改革为科学的出现做了必要的铺垫,哲学家、自然研究者与高级工匠的结合,科学机构的建立,欧洲社会在1600年前后所呈现出的前所未有的开放性、好奇心和驱动力,强烈的个人主义和扩张精神,以及积极入世的新教伦理 ...
方在庆
core  

基于磁电复合材料的四态存储器 [PDF]

open access: yes, 2008
四态存储器是一种能够在一个存储单元内记录四种信息状态的新型存储器.采用磁电复合材料Co/PZT制作了一个四态存储器的存储单元原型,该存储单元的磁电输出信号随外磁场变化存在明显的滞回现象.根据磁电滞回现象,提出了施加偏置磁场的读取原理,实际测试结果给出了区别明显的15.8μV,?4.4μV,5.5μV,?11.3μV四种信号,初步演示了磁电复合材料用作四态存储器的可行性.国家自然科学基金(批准号:50571084); 国家高技术研究发展计划(编号:2006AA03Z101 ...
刘兴军   +3 more
core  

Gas Sensor Array Signal Detection System [PDF]

open access: yes, 2009
介绍在一个VC平台下与PIC单片机互连的数据采集系统。利用PIC单片机实现硬件的数据采集,利用VC++编写上位机界面,实现数据的动态曲线显示。In this paper,a data acquisition system based on VC platform interconnecting with a PIC single-chip machine is introduced.A PIC single-chip machine is used to collect the data.The ...
冯勇建, 杨雅雯
core  

Design and Simulation of a New Axial-field Permanent-magnet DC Generator [PDF]

open access: yes, 2008
对一种新型小功率盘式永磁直流风力发电机的原理和电磁设计进行了分析和推导,利用Ansoft Maxwell 3D软件对电机的磁场分布和运动情况进行了仿真,其结果可为进一步研究提供参考。In this paper,an innovative model of vertical-axis permanent-magnet direct-current wind-energy generator has been presented.Its working principle and ...
杜华夏   +3 more
core  

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