J. C. Feng
,
M. Naka
,
J. C. Schuster(School of Materials Science and Engineering
,
Harbin Institute of Technology
,
Harbin
,
150001
,
China
,
Joining and Welding Research Institute
,
Osaka University
,
Mihogaoka 11 - 1
,
Ibaraki
,
Osaka 567
,
Japan
,
Institute of Physical Chemistry
,
University of Vienna
,
Austria )
金属学报(英文版)
Bonding of SiC to SiC using Ni and Ni - 25at%Cr foils was performed at high temperature.Interface structures and reaction phases were investigated by EPMA analyses and XRD diffraction method, re- spectively. At a bonding temperature of 1273K Ni reacts with SiC and forms various Ni silicides con- taining graphite baside SiC. Ni3Si without graphite was formed at Ni side.The interface structure of SiC/Ni joint was SiC/Ni2Si + C/Ni31 Si12 + G/Ni3 Si/Ni. At the interface between SiC and Ni- 25at%Cr alloy the Ni silicide was only Ni2Si at the same bonding temperature,and further(Cr, Ni)7 (Si, C)3 carbide was formed between Ni silicide + graphite zone and Ni - 25at%Cr alloy.The interface structure of SiC/Ni - 25at%Cr alloy was SiC/Ni2Si + C/(Cr, Ni)7 (Si, C)3+Ni(ss. Cr, Si)/Ni - 25at%Cr.
关键词:
interfacial structure
,
null
,
null
,
null
姜志进
原子核物理评论
在核吸收与随动者吸收理论的基础上,给出了在有QGP相变情况下高能重离子碰撞中的J/Ψ微分产生截面,并用其讨论了CERN的NA50合作组给出的入射动量为158 AGeV/c的Pb-Pb碰撞中的J/Ψ反常抑制现象。理论较好地解释了实验结果。
关键词:
J/Ψ反常抑制
,
核吸收
,
随动者
吉日木图
原子核物理评论
研究自旋和轨道量子数不同的介子之间的质量劈裂对检验夸克势模型非常重要.在以往的夸克势模型计算中,η_c-J/ψ的质量劈裂都很难达到实验的值.用正规化形状因μ~2/(q~2+μ~2),在对完整的动量空间中的Breit夸克势实施一次正规化下研究了η_c-J/ψ和新介子ηb与Υ(1s)之间的质量劈裂.结果表明,正规化形状因子中的屏蔽质量μ应与介子折合质量有关,当将其展开为介子折合质量的三阶多项式时,上述介子质量劈裂可以精确重现实验的结果.另外,由于完整的Breit 势包含有自旋一轨道耦合相互作用的项,因而还可以研究χ_(c0),χ_(c1)和χ_(c2)之间的质量劈裂.
关键词:
夸克势模型
,
矩阵元
,
介子束缚态
,
正规化
,
质量劈裂
董元篪
,
魏寿昆
,
彭(忄育)强
,
朱元凯
金属学报
<正> As一向认为是钢铁中的有害元素。除少数耐腐蚀钢种外,脱As是钢铁冶炼的一个问题。欲脱As必先知As在铁液中的热力学行为。文献中只报道过As的活度相互作用系数e_(As)~C,e_(As)~S及e_(As)~N。本文是继续前文研究As在Fe液中的热力学行为,旨在利用下列反应: 3(CaC_2)+2[As]=(Ca_3As_2)+6[C] (1) 求出Fe-As-C-j熔体中的
关键词:
陈建刚
,
卢凤双
,
张敬霖
,
张建生
,
张建福
金属功能材料
3J33(C)马氏体时效钢是以无碳(或超低碳)铁镍马氏体为基体的时效强化型高弹性合金.采用工业电炉处理合金,高温固溶处理后,再经过4次变温循环相变,基体组织由高温固溶后220 μm的粗大等轴晶细化为15 μm左右的均匀细小晶粒.进一步时效处理后,合金抗拉强度、屈服强度、弹性极限、硬度提高10%以上,断面收缩率、断后伸长率、冲击吸收功提高30%以上.
关键词:
马氏体时效钢
,
变温循环相变
,
时效
,
力学性能
王忠纯
,
沈法华
,
刘成林
量子电子学报
doi:10.3969/j.issn.1007-5461.2011.01.011
研究了腔间有耦合的双J-C模型中原子纠缠的动力学,分析了腔间耦合系数A和原子的初态对原子纠缠的猝灭(ESD)和猝生(ESB)的影响.通过对原子间共生纠缠度的数值分析发现,当原子初态为第一类类Bell态时,不会出现ESD和ESB,腔间的耦合可使原子的纠缠加大,并能使初态为分离态的原子产生纠缠.当原子初态为第二类类Bell态时,A的大小可改变出现ESD与ESB的时间间隔,或决定是否出现ESD,但腔间的耦合不能使初态不纠缠的原子产生纠缠.
关键词:
量子光学
,
耦合谐振腔
,
双J-C模型
,
共生纠缠度
,
纠缠的猝灭
,
纠缠的猝生
封玲娟
,
张英杰
,
夏云杰
量子电子学报
doi:10.3969/j.issn.1007-5461.2013.06.012
研究了受经典场驱动的两个二能级原子分别与两个单模腔场相互作用模型中两原子的纠缠动力学行为.该工作主要是对经典场驱动存在的J-C模型进行研究,采用数值计算的方法,详细分析了纠缠初始状态以及经典场的驱动强度对原子纠缠和转移特性的影响.结果表明,适当调节经典场驱动强度,可以使原子的纠缠突然死亡现象得到抑制,同时实现原子与腔场间的最大转移.
关键词:
量子光学
,
量子纠缠
,
部分转置矩阵负本征值
,
经典场驱动
Journal of Physics-Condensed Matter
The temperature dependences of the magnetization, internal energy and specific heat in a three-sublattice ferrimagnet or ferromagnet with /J(ab)/ = /J(bc)/ not equal /J(ca)/ are calculated within the framework of the linear spin-wave approximation, by employing retarded Green's functions. For both the ferromagnet and the ferrimagnet, the internal energy and the specific heat decrease with increasing J ' /J and/or the value of the spins. For fixed values of S,, Sb, S, and J ' /J, the internal energy and the specific heat increase, whereas the sublattice magnetization decreases with increasing temperature theta. The three-sublattice ferrimagnet has some particular characteristics which are not shown by the systems with two sublattices. For ferrimagnets, the antiferromagnetism of the system becomes weaker with increasing J ' /J. The sublattice magnetization at low temperatures (also the magnetization M(0) at 0 K) of a ferrimagnet increases with increasing J ' /J for fixed values of S(a), S(b) and S(c). The effects of the spins S(a) (S,) and Sb On the magnetizations of other sublattices differ. The characteristics of the a-sublattice are the same as those of the c-sublattice, due to their similarity as well as the symmetry of the system. The behaviours of the b-sublattice are different from those of the a- and c-sublattices, due to the asymmetry of the three-sublattice system. The spin-value dependences of the spin deviation Deltam per spin land also the energy for the zero-point quantum fluctuation) of the system are different for different sublattices. These differences are ascribed to the asymmetry of the three-sublattice systems, which leads to the new intrinsic properties of the systems.
关键词:
layered heisenberg ferrimagnets;spin-wave theory;elementary;excitations;superlattices;systems;magnetoresistance;antiferromagnet;interfaces
胡要花
量子电子学报
doi:10.3969/j.issn.1007-5461.2012.04.010
考虑一个二能级原子与单模热光场经由双光子过程耦合,采用量子约化熵研究了原子和场的约化熵变化规律,用共生纠缠度(Concurrence)研究了原子与场之间的纠缠演化.借助于数值计算方法,详细分析了在混态J-C模型中,Stark位移和平均光子数对约化熵变和纠缠的影响.结果表明在Stark位移影响下,原子和光场的约化熵变化量均减小.选择适当的原子初态,可以使得原子的约化熵和光场的约化熵发生交换.此外,考虑Stark位移时,原子与光场之间纠缠的最小值增大,原子与光场不再出现退纠缠态.
关键词:
量子光学
,
纠缠
,
共生纠缠度
,
量子约化熵
,
Stark位移
,
Jaynes-Cummings模型
