Some Properties of Quasi-keep-range Operators and Their Applications

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基于矩阵初等变换的n元函数极值的快速判别法

给出了 n元函数极值的一个充分条件 ,并结合矩阵的初等变换建立了 n元函数极值的一种快速判别法 ,最后给出了一个例子     

多个硅通孔引起的热应力对迁移率和阻止区的影响

本文主要讨论了多个硅通孔引起的热应力对迁移率和阻止区的影响, 得到了器件沟道沿[100]方向时, 硅通孔之间的角度和间距对电子迁移率和阻止区的影响. 设定两种阻止区区域, 即迁移率变化分别为5%和10%的区域, 且主要考虑相邻TSV之间的区域. 仿真结果表明: 当硅通孔和X轴所成角度为π/4时, 电子迁移率变化和阻止区区域最小, 但是可布置器件区域不规则, 不易于布局. 随着间距的增加, 电子迁移率变化和阻止区区域逐渐增大, 趋向于单个TSV的情况; 当角度为0 时, 电子迁移率变化和阻止区区域变大, 可布置器件区域为硅通孔围成的中心小区域上, 形状比较规则, 便于布局. 而且随着间距的增加, 电子迁移率变化和阻止区区域越来越小, 趋向于单个硅通孔的情况.     

Emittance-dominated long bunches in dual harmonic RF system

The storage of long bunches for long time intervals needs flattened stationary buckets with a large bucket height. The longitudinal motion of the initially mismatched beam has been studied for both the single and dual harmonic RF systems. The RF amplitude is determined to be r.m.s wise matched. The bucket height of the single harmonic system is too small even for shorter bunch with only 20% increased energy spread. The Halo formation and even debunching can be seen after a few synchrotron periods for single particles with large amplitude. In the case of small energy spread for a cooled beam, Coulomb interaction cannot be ignored. The external voltage has to be increased to keep the r.m.s bunch length unchanged. The new voltage ratio R(N) simplifies physics for the emittance-dominated bunches with modest particle number N. For the single harmonic system, substantial amount of debunching occurs without increasing the external voltage, but very little if the RF amplitude is doubled. Results from the ORBIT tracking code are presented for the 1 GeV bunch in the HESR synchrotron, part of the GSI FAIR project.     

Bipartite entanglement in spin-1/2Heisenberg model

The bipartite entanglement of the two-and three-spin Heisenberg model was investigated by using the concept of negativity.It is found that for the ground-state entanglement of the two-spin model,the negativity always decreases as B increases if A Δ＜y-1,and it may keep a steady value of 0.5in the region of B＜J[(Δ+1)2-y2]1/2if Δ＞y-1,while for that of the three-spin model,the negativity exhibits square wave structures if y=0 or Δ=0.For thermal states,there are two areas showing entanglement,namely,the main region and the sub-region.The main region exists only when Δ＞Δc(Δc1=and(y2-1)/2for the 2-and 3-spin model respectively)and extends in terms of B and T as Δ increases,while the sub-region survives only when y≠0 and shrinks in terms of B and T as Δ increases.