排序方式: 共有36条查询结果,搜索用时 15 毫秒
1.
2.
3.
4.
Leeming Chen Hezhong Guo Han-Ying Chen Ming-Hsiung Tsao Tz-Te Yang Yi-Chin Tsai Kwo Ray Chu 《IEEE transactions on plasma science. IEEE Nuclear and Plasma Sciences Society》2000,28(3):626-632
We report experimental investigation of a novel scheme for efficient interaction between a linear electron beam and an electromagnetic wave in a complex extended interaction structure. The structure of interest consists of a high R/Q, five-gap, coupled-cavity resonator that incorporates a coaxial section of a quarter plasma wavelength placed between the first and second cavities. In the coaxial section, beam and wave propagate in separate channels. The first cavity, strongly coupled to the other cavities through the wave channel of the coaxial section, serves as a buncher cavity. An inner channel running through the center conductor of the coaxial section provides a cutoff drift space for ballistic bunching of electrons, an effect that is shown to significantly enhance the interaction efficiency. Oscillation power of 2.2 kW at 16.6 GHz was demonstrated with an interaction efficiency of 30%. The total efficiency was further increased to 41% by incorporation of a two-stage depressed collector 相似文献
5.
6.
7.
8.
Millsap KW Bos R Busscher HJ van der Mei HC 《Journal of colloid and interface science》1999,212(2):495-502
Adhesive interactions between yeasts and bacteria are important in the maintenance of infectious mixed biofilms on natural and biomaterial surfaces in the human body. In this study, the extended DLVO (Derjaguin-Landau-Verwey-Overbeek) approach has been applied to explain adhesive interactions between C. albicans ATCC 10261 and S. gordonii NCTC 7869 adhering on glass. Contact angles with different liquids and the zeta potentials of both the yeasts and bacteria were determined and their adhesive interactions were measured in a parallel-plate flow chamber.Streptococci were first allowed to adhere to the bottom glass plate of the flow chamber to different seeding densities, and subsequently deposition of yeasts was monitored with an image analysis system, yielding the degree of initial surface aggregation of the adhering yeasts and their spatial arrangement in a stationary end point. Irrespective of growth temperature, the yeast cells appeared uncharged in TNMC buffer, but yeasts grown at 37 degrees C were intrinsically more hydrophilic and had an increased electron-donating character than cells grown at 30 degrees C. All yeasts showed surface aggregation due to attractive Lifshitz-van der Waals forces. In addition, acid-base interactions between yeasts, yeasts and the glass substratum, and yeasts and the streptococci were attractive for yeasts grown at 30 degrees C, but yeasts grown at 37 degrees C only had favorable acid-base interactions with the bacteria, explaining the positive relationship between the surface coverage of the glass by streptococci and the surface aggregation of the yeasts. Copyright 1999 Academic Press. 相似文献
9.
Lifetime of levels up to 22+, have been measured in 78Kr and an oblate shape is assigned to the ground state using the CSM and the configuration dependent shell correction calculations.
Calculations further show that 78Kr is highly γ-soft nucleus. The experimental Q
t values coupled with theoretical calculations indicate an oblate shape for 78Kr at low spins and triaxial shape at higher spins 相似文献
10.
Lifetimes of high spin states up to {
}=22+ in the yrast positive parity bands have been measured to investigate the shape evolution with increasing spin in 72, 74Se. The Q
t values derived from these measurements indicate that prolate shape stabilizes for 72Se, while a triaxial shape develops for 74Se at higher spins. Comparison of the observed trend in Q
t with spin for 72, 74Se with that of the corresponding kryptones isotones emphasizes the stability provided by N=38 prolate shell gap even at high rotational frequency. 相似文献