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Gammasphere上裂变丰中子核核结构若干前沿领域的新进展(Ⅰ:第一和第二部分)

罗亦孝 , J.H.Hamilton , J.O.Rasmussen , A.V.Ramayya , C.Goodin , A.V.Daniel , N.J.Stone , 朱胜江 , J.K.Hwang , 刘少华 , C.J.Beyer , 李科 , H.L.Crowell , D.Almehed , S.Frauendorf , A.Covello , V.Dimitrov , 张敬业 , 车兴来 , 姜卓 , D.Fong , A.Gelberg , I.Stefanescu , A.Gargano , E.F.Jones , P.M.Gore , I.Y.Lee , G.M.Ter-Akopian , Yu.Ts.Oganessian , M.A.Stoyer , R.Donangelo , 马文超 , J.D.Cole , J.Kormicki , 张学谦 , S.C.Wu , J.Gilat , T.N.Ginter , S.J.Asztalos

原子核物理评论

使用Gammasphere多探测器系统对252Cf裂变源瞬发γ射线进行γ-γ-γ和γ-γ(θ)符合测量,裂变丰中子原子核核结构若干前沿领域的深入研究获得了新的进展.高达5.7×1011以上的三重和更高重符合事件的数据统计,以及更少压缩的三维数据为宽广未知丰中子核区的寻找和研究提供了有利的条件.在具有重要物理意义的若干丰中子核区首次建立,或显著扩展了一批包括转晕态和转晕附近能态的高自旋能级纲图.在偶-偶丰中子核110,112Ru和108Mo中鉴别出了手征对称破缺结构.丰中子110,112Ru附近核的三轴形变基态具有最低的能量,在它们之中已确认了接近最大值的三轴形变.在这些Ru和Mo同位素中观察到的手征双线能带展示出手征破缺的一切特征,特别是其理想的能量简并,表明它们在迄今已报道的手征破缺结构中,具有最好的手征特性.研究了手征结构从具有γ软度的108Ru到具有大三轴形变的110,112Ru的过渡.斜轴推转(TAC)和随机相近似(RPA)理论计算成功地拟合了在这些偶-偶丰中子核中观察到的手征双线能带的特性,并指定其为软手征振动态.在这些偶-偶核中观察到的手征破缺不可能归纳为奇-奇核中那样的简化的几何图像.前者来自闭壳外所有中子的相互作用.对双幻核132Sn附近N=83同中素链的系统研究为这个极富吸引力的核区提供了大量新的谱学信息.N=83同中素135Te(Z=52),134I(Z=53),137Xe(Z=54),138Cs(Z=55)和139Ba(Z=56)的最新能级信息,特别是首次建立的138Cs高自旋能级纲图和壳模型理论计算表明,Z=50质子闭壳外少数g7/2价质子激发同N=82中子闭壳外之唯一F7/2价中子的耦合对该核区能级结构具有关键作用.观察到了132Sn和208Pb附近核区谱学信息的相似性和相对应的三粒子和五粒子态.在135Te中观察到了磁转动,这是在双幻核132Sn附近观察到的首例磁转动.

关键词: 丰中子核 , 高自旋 , 转晕态 , 裂变 , 252Cf , γ射线三重符合 , 角关联 , Gammas-phere多探测器系统 , 手征对称破缺 , 三轴形变 , 斜轴推转(TAC)计算 , 软手征振动 , N=83同中数链 , 双幻核132Sn , 壳模型计算 , 磁转动 , 谱学相似性

Gammasphere上裂变丰中子核核结构若干前沿领域的新进展(II:第三和第四部分)

罗亦孝 , J.H.Hamilton , J.O.Rasmussen , A.V.Ramayya , C.Goodin , A.V.Daniel , N.J.Stone , 朱胜江 , J.K.Hwang , 刘少华 , C.J.Beyer , 李科 , H.L.Crowell , D.Almehed , S.Frauendorf , A.Covello , V.Dimitrov , 张敬业 , 车兴来 , 姜卓 , D.Fong , A.Gelberg , I.Stefanescu , A.Gargano , E.F.Jones , P.M.Gore , I.Y.Lee , G.M.Ter-Akopian , Yu.Ts.Oganessian , M.A.Stoyer , R.Donangelo , 马文超 , J.D.Cole , J.Kormicki , 张学谦 , S.C.Wu , J.Gilat , T.N.Ginter , S.J.Asztalos

原子核物理评论

使用Gammasphere多探测器系统对252Cf裂变源瞬发7射线进行γ-γ-γ和γ-γ(θ)符合测量,A~100(Z~40,N>56)丰中子核区关于形状过渡、形状共存和形状突变的深入研究获得了新的进展.奇-Z核的系统研究揭示了从Z=39(Y)同位素的轴对称大四极形变到Z=43(Tc),44(Ru)和45(Rh)同位素中具有中等四极形变之大三轴形变的过渡.Nb(Z=41)同位素具有过渡核的特征.根据邻近同位素和同中素带交叉信息的系统性及推转壳模型(CSM)计算,Tc和Rh偶-N同位素中观察到的带交叉产生于一对h11/2中子的转动顺排.首次观察到100Nb(Z=41,N=59)的高自旋能级纲图和形变态,从而证实了100Nb中的形状共存,并确认,在Nb同位素链上,基态形状突变发生于N=58(球形)到N=59(大形变);而在Sr(Z=38),Y(Z=39)和Zr(Z=40)各同位素链上,基态形状突变均发生于N=59(球形)到N=60(大形变).100Nb具有大形变基态,同现有理论预言相矛盾,其大形变的基态及转动带所具有的很大的和不规则的转动惯量具有重要的理论意义. 对奇-质子Cs(Z=55)和La(Z=57)丰中子同位素八极激发的详细研究,发现了141,143,144Cs同位素链上电二极矩D.随中子数增加而减小的急剧变化,此前在145,147La中观察到的电二极矩Do的较缓和的减小似乎亦很陡地下延至148La.在Cs和La同位素中观察到的电二极矩D.的急剧下降很可能同偶-质子核146Ba和224Ra中观察到的电二极矩D.的急剧下降相类似,后者已获反射非对称平均场壳修正理论的成功解释.实验证明,141Cs具有很大电二极矩D.141Cs和142Xe中观测到的很大的电二极矩D.和仅在141Cs中观察到的电二极矩D.的simplex量子数相关性需要进一步的理论研究.根据转动频率比值ω-(I)/ω+(I)的检定,同Xe同位素一样,认定Cs同位素中包括号143Cs的八极激发为八极振动,而在La同位素中存在八极形变.

关键词: 形状过渡 , 轴对称形状 , 三轴形变 , 形状突变 , 带交叉 , 奇-质子 , 八极激发 , B(E1)/B(E2)比值 , 电二极矩D0 , 二极矩的下降 , 八极振动 , Cs,La同位素

Thermodynamic Behaviour of Fe-S-RE,Fe-Csat.-S-RE,Ni-S-RE,Cu-S-RE Solutions

Ting DU Longmei WANG Yeming WU Yuqing ZHANG Aisheng LIU Central Iron and Steel Research Institute , Beijing , 100081 , China

材料科学技术(英文)

The temperature dependences of the equilibrium constants for the reactions RES_((S))=[RE]+[S]. (RE=Ce,La,Nd,Sm,Y),of the standard Gibbs energies for the RES formed and of the interaction coefficients between RE elements and S for the Fe-base,Ni-base and Cu-base solutions are sum- marized.

关键词: thermodynamics , null , null , null , null

Quantum transport of Au-S-S-Au nanoscale junctions

Applied Physics Letters

Transport in S(2) molecules sandwiched between Au electrodes is investigated with a combination of density functional theory and the non-equilibrium Green's function method. We consider four different configurations and find that their conductances are related to the details of the bonding geometry. When S(2) connects to pyramidal-shaped electrodes at the top site, the transmission is governed by a resonance and is strongly affected by the bias. In contrast, the transport of the remaining three configurations is through several closely spaced broad molecular orbitals, and the transmission coefficient is almost flat around the Fermi level. (C) 2012 American Institute of Physics. [doi:10.1063/1.3665614]

关键词: conductance;molecule

EQUILIBRIUM OF Mg-S IN Ni MELTS

WANG Conghua HAN Qiyong University of Science and Technology Beijing , Beijing , China WANG Conghua Faculty of Physical Chemistry of Metallurgy , University of Science and Technology Beijing , Beijing , China

金属学报(英文版)

The equilibrium of Mg-S in Ni melt was studied by the method of vapour equilibrium in a sealed chamber.At 1530℃ the equilibrium constant of the reaction MgS_(s)=Mg_(Ni)+S_(Ni)and the activity interaction coefficient were determined as K_(MgS)=6.76×10~(-5)and e_S~(Mg)=-9.1.

关键词: Equilibrium constant , null , null , null , null

S49钢轨轧制工艺设计

陈亚平 , 王彦中 , 陶功明

钢铁钒钛 doi:10.3969/j.issn.1004-7638.2002.01.007

结合攀钢轨梁厂工厂特点及S49钢轨断面特点,论述了S49钢轨的轧制工艺设计,并着重阐述了孔型系统的选择和孔型参数的确定,同时设计了导卫装置等.通过孔型系统的优化设计,使S49钢轨一次试轧成功.

关键词: S49钢轨 , 孔型设计 , 导卫装置

EQUILIBRIA OF Sr,Ba AND O,S IN LIQUID Fe

YUE Kexiang DONG Yuanchi East China Institute of Metallurgy , Ma'anshan , China

金属学报(英文版)

The equilibrium constants between Sr-O,Ba-O and Sr-S,Ba-S in liquid iron at 1570℃ and the interaction coefficients concerning these elements have been determined as follows: K_(Sro)=1.897×10~(-7),e_O~(Sr)=-43.8 K_(BaO)=8.204×10~(-8),e_O~(Ba)=-98.0 K_(SrS)=8.356×10~(-7),e_S~(Sr)=-3.9 K_(BaS)=4.083×10~(-7),e_S~(Ba)=-3.5

关键词: equilibrium , null , null , null , null

H2S应力腐蚀试验用H2S气通设计

孙耀峰

腐蚀学报(英文) doi:10.3969/j.issn.1002-6495.2001.z1.007

在满足H2S应力腐蚀试验的试验条件下,设计了H2S应力腐蚀实验室中H2S气体的通气装置.设计方案切实易行,安全可靠;实现了出口H2S气体的吸收再利用,减少了对环境的污染.

关键词: H2S气体 , 设计方案 , H2S应力腐蚀试验 , 环境保护

Thermodynamic discussion on Young's equation in wetting

Zeitschrift Fur Metallkunde

Young's equation is discussed on a thermodynamic basis. The result shows that the equation is a thermodynamic equilibrium of the wetting system rather than a force balance. The equilibrium satisfies the general equilibrium condition, that is, Gibbs free energy should be minimum when the wetting equilibrium is reached. The validity of Young's equation is only limited to some special cases, namely if the droplet shape is an exact sphere sector. It implies that Young's equation can only be used in the case without the action of gravity. If the curve of the liquid surface changes, the term of cos theta in Young's equation should be replaced by another functional form of the contact angle theta. In the discussion, the author suggests that, in the case of a solid, the surface energy should be considered rather than the surface tension, and the concept of a solid surface tension should be reconsidered based on the difference between a liquid surface and a solid surface.

关键词:

NUMERICAL SIMULATION OF CASTING'S MOLD FILLING PROCESS

J.X. Zhou , R.X. Liu , L.L. Chen , D.M. Liao , H.S. Wei

金属学报(英文版)

Numerical simulation of casting's mold filling process is the main and the most important aspect of the foundry CAE technology. But it is time-consuming; it may take dozens of hours or several days. While with the development of computer hardware, numerical simulation of casting's mold filling process has made rapid progress. The simulation results, therefore, have become more and more practical. This study tries to find some clues of the computational time of mold filling process. Firstly, this paper introduces mathematic model and the basic route of numerical simulation of casting's mold filling process. Then the computational time of mold filling process has been carefully studied, and some new and useful results have been gained from the study of the computational time. Finally, this paper has given some real applications of numerical simulation of casting's mold filling process.

关键词: numerical simulation , null , null

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