脉冲磁体增强技术发展概述

在脉冲强磁体设计中，磁应力是目前面临的最大困难，当磁场强度达到100T时，磁体绕组中的磁应力高达4GPa，这是目前任何实用导体材料都无法随的，因此，脉冲强磁体的发展在很大程度上取决于磁应力的解决情况，文章介绍了国外在解决脉冲强磁体巨大问题上采用的方法，主要叙述了新材料技术，绕组加固技术和改善电流分布技术，并对其优缺点及性能进行了分析。     

Experimental Evaluation of the Effect of the Structure of Composite Rings on Their Properties in the Radial Direction

Based on the results of bending tests on cut glass-fiber-reinforced plastic rings with a longitudinal-circumferential reinforcement, their radial peel strength is evaluated. The effect of the fiber layout on the properties of the rings in the radial direction is investigated. It is shown that their radial tensile strength only slightly depends on the fiber layout but is basically determined by the properties of the polymer interlayer between the fibers. In radial tension, the presence of fibers in the polymer layer leads to a strain concentration, which results in a premature failure of the polymer phase of the composite. The strain-concentration factor cannot be used for an accurate prediction of the breaking stresses or strains of the composite, because of different failure modes of the pure resin and the composite.     

PRESSURE DROP ACROSS A FIXED BED REACTOR WITH MECHANICAL FAILURE OF CATALYST PELLETS DESCRIBED BY SIMPLIFIED ERGUN‘S EQUATION

The pressure drop across a laboratory-scale catalyst packed bed with mechanical failure of catalyst pellets has been examined. It was found that the increased pressure drop can be described by a simplified model deduced from Ergun‘s equation. The pressure drop is determined mainly by the term of viscous energy loss.     

类铍CⅢ 和 OⅤ离子激发态的相对论能量和跃迁几率

利用多组态相互作用方法及Rayleigh-Ritz变分法,计算了类铍CⅢ和OⅤ离子激发态1s22s2p1P0,1s22s2p3P0,and 1s22p2 3P的能量,包括了相对论能量和质量极化效应。计算了相关态的振子强度、跃迁几率和波长。计算结果与其它理论和实验结果符合得很好。     

铁道外锁闭铁在脉动载荷下的强度分析

对道岔外锁闭铁建立有限元模型，计算其在工作载荷下的应力场，发现结构的大部分区域应力很小，而部分角点处存在很大的应力集中，其中最大应力集中处也是实际破坏部位；比较了常用的脉动载荷下的强度理论，针对本文的工况选用其中的Goodman脉动强度理论解释了该结构的破坏原因，并给出了容许的最大工作载荷．     

Fe40—45Cr30—35Co20—25Mo0—4Zr0—2合金微观结构对力学性能的影响

研究了高矫顽力型FeCrCo合金力学性能和微观结构间的关系.对抗弯强度和断裂韧性的测试 结果表明，高矫顽力型FeCrCo合金的力学性能远低于普通FeCrCo合金.透射电镜照片显示高 矫顽力合金的两相成分差较大；x射线衍射结果反映高矫顽力合金衍射峰强度较弱而半高宽 较大，说明高矫顽力合金中调幅分解进行彻底.合金中α₁，α₂两 相成分差的扩 大使晶格错配度增加，强度提高，韧性降低.这就是高矫顽力合金力学性能变差的原因. 关键词： 力学性能 调幅分解 抗弯强度 断裂韧性     

Photocrosslinking of ultra high strength polyethylene fibers

Ultra high strength polyethylene (HSPE) fibers have been successfully photocrosslinked using benzophenone as photoinitiator. The introduction of photoinitiator without disturbing the fiber structure is a difficult problem which was solved by vapor absorption at elevated temperature while keeping the fiber under constant strain. The crosslinked fiber showed no decrease in mechanical properties at room temperature as is the case when fibers are crosslinked by other reported methods such as radiation and chemical crosslinking. The crosslinked fiber showed enhanced high temperature resistance as well as much lower creep rate on prolonged stressing. Photocrosslinking of HSPE fiber is superior to other crosslinking methods reported in the literature.     

Properties unique in nuclei far from β stability line

Nucleons with very small binding energies present in nuclei far from the β stability line produce a unique shell structure, which leads to the disappearance of traditional magic numbers or to the creation of new magic numbers and new deformation regions. We study the shell structure in terms of the variation of two important ingredients, the kinetic energy and the spin-orbit splitting, as a function of the orbital angular momentum ℓ, when binding energies of neutrons decrease towards zero. It is also shown that for low-lying threshold strength, a negative sign is possible for the polarization charge coming from the coupling of one-particle to isoscalar shape oscillations. Received: 1 May 2001 / Accepted: 4 December 2001     

类钠等电子系列振子强度与原子实极化系数计算

应用屏蔽氢模型计算类钠等电子系列电偶极子跃迁振子强度f和原子(离子)实极化系数α,计算结果和有关文献是一致的;并讨论极化系数随主量子数、原子序数的变化情况.     

Acidity of Several Anilinium Derivatives in Pure Tetrahydrofuran

The acidity constant (pK _a) of eleven substituted anilinium ions and the dissociation constants of their perchlorate salts (pK _salt) were determined in pure tetrahydrofuran by potentiometry and conductometry. The pK _a values of the studied aniliniums extend downward the range of previously determined pK _a values. The resolution of acid strength for cationic acids in tetrahydrofuran was compared with those obtained in other amphiprotic and aprotic solvents. It is shown that the resolution in tetrahydrofuran is higher than the ones in water and methanol, similar to those in acetone, dimethyl sulfoxide and isobutylmethylketone, but lower than those in acetonitrile and nitromethane.