N A Al‐Anani and Jewell D GW Howe
Due to their high magnetizing field requirement, the emergence of rare‐earth based permanent magnets is creating onerous demands on the capacitor‐discharge systems which are used…
Abstract
Due to their high magnetizing field requirement, the emergence of rare‐earth based permanent magnets is creating onerous demands on the capacitor‐discharge systems which are used for their initial magnetization, a process which is aggravated by the fact that the transient current pulse induces eddy currents, which inhibit the penetration of the magnetizing field, and causes heating and stressing of the magnetizing fixture. The problems are compounded in multi‐pole and post‐assembly magnetization systems, particularly for fine pole‐pitch fields. However this paper concentrates on the pre‐magnetization of magnets in air‐cored solenoids, which, despite the difficulty in subsequently handling magnetized magnets, remains the most common requirement. It presents a methodology for the design of impulse magnetizing solenoids to produce the amplitude and time to peak of magnetizing field required for a specific generic type and aspect ratio of magnet to be magnetized, and describes a procedure for the subsequent analysis of the complete impulse magnetization system.
An emerging, globally Web‐based Chinese language virtual library offers unprecedented content availability and user accessibility. Virtual and physical libraries are defined, and…
Abstract
An emerging, globally Web‐based Chinese language virtual library offers unprecedented content availability and user accessibility. Virtual and physical libraries are defined, and compared, in terms of bibliographical searching. Then, the size of the Chinese language virtual library is estimated and its future development is predicted. The quantitative analysis concentrates on the content of this virtual library through examining the subject directories of more than 100 of its search engines. The findings show that 20 percent of the subject categories provide 80 percent of online access activities. Many subject categories characterise values of the Chinese‐speaking world. Discussion continues with structural and functional analyses of Chinese language search engines that support this virtual library. Further, an analytic overview is presented of Chinese language applications that render the necessary and sufficient computational linguistic conditions for utilising Chinese language online resources.