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质子数Z分别位于Ru之上和之下的A～(100～126)丰中子原子核三轴形变在原子核形状变迁和共存中的重要作用(英文)

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原子核物理评论 2015年第1期32卷 1-23页

作者：罗亦孝 j.H.Hamilto. j.o.rasmussen A.V.Ramayya S.Frauendo.f 王恩宏 j.K.Hwang 王建国李红洁杨韵颐朱胜江刘艳鑫焦长峰梁午阳石跃许甫荣孙扬刘少华 N.T.Brewer I.Y.Lee G.M.Ter-Ako.ian A.V.Daniel Yu.o.anessian M.A.Sto.er R.Do.angelo.马文超 Physics Department Vanderbilt University Lawrence Berkeley Natio.al Labo.ato.y Department o. Chemistry U.C.Berkeley Department o. Physics University of Notre Dame Institut für Strahlenphysik FZD-Rossendorf Department o. Physics Tsinghua University Scho.l o. Science Huzhou Teachers College Scho.l o. Physics Peking University Department o. Physics and Astro.o.y Shanghai Jiao Tong University Institute o. Mo.ern Physics Chinese Academy of Sciences Chemistry Department University of Kentucky Physics Divisio. Oak Ridge National Laboratory Flero. Labo.ato.y fo. Nuclear Reactio.s JINR Lawrence Livermo.e Natio.al Labo.ato.y Instituto.de Fisica Facultad de Ingenieria Physics Department Mississippi State University

基于Ru(Z=44)丰中子同位素中存在最大三轴形变的理论预言和实验证据,综述了近年来Rh(Z=45),Pd(Z=46),Ag(Z=47),Cd(Z=48)(质子数Z位于Ru,Z=44之上)及Zr(Z=40),Nb(Z=41),Mo.Z=42),Tc(Z=43)(质子数Z位于Ru,Z=44之下)的A～(100～126)丰中子同位素中关于三轴形变的形状变迁和形状共存系统性研究的重要进展。252Cf自发裂变瞬发γ射线γ-γ-γ三重符合、特别是新建立的γ-γ-γ-γ四重符合数据的系统观测和研究,在Ru,Pd,Cd和Nb丰中子同位素中显著扩展或首次观测到了一系列能带,为这个核区原子核形状的研究提供了新的、重要的实验数据。联系此前报道的有关进展,使用PES,TRS,PSM,CCCSM和SCTAC理论模型计算拟合新的实验数据,在该核区沿同中素和同位素链,并随自旋和激发能变化各自由度,跟踪原子核形状渐进变化,获得了新的系统性研究成果,显著扩展和深化了人们对原子核形状变迁和形状共存的认知。对于Ru及其上的Rh(Z=45),Pd(Z=46),Ag(Z=47)和Cd(Z=48)丰中子同位素的研究表明:Rh丰中子核具有比最大值稍小的三轴形变,γ=-28°,并在103–106Rh同位素链上鉴别出了手征对称破缺;在三轴形变核112Ru和114Pd(N=68)中发现了三轴原子核的摆动运动,该摆动运动也可能在114Ru(N=70)中存在;观察到了从具有最大三轴形变的110,112Ru中手征破缺到稍小三轴形变的112,114,116Pd中扰动的手征破缺的过渡;在较软的Ag核中观察到了丰富的谱学结构,在104,105Ag中鉴别出了可能的手征对称破缺,在较重的115,117Ag中提出了趋于三轴形变的γ软度;具有小形变的Cd核的能级结构被解释为准粒子耦合、准转动和软三轴形变;最近的库伦激发的研究提供了Z=50,N=82满壳附近122,124,126Cd核中出现核集体性的实验和理论证据;上述研究成果展现出从Ru中的最大三轴形变(γ=-30°,三轴形变极小增益为0.67 Me V),经具有大三轴形变的Rh核(γ=-28°),到Pd核中的稍小、但稳定于中等自旋到高自旋区的三轴形变(γ～-41°,三轴形变极小增益为0.32 Me V),再经Ag核中的γ软度,最后到具有很小形变、但仍出现集体性质、包括软三轴形变的Cd核的过渡。对于Pd核转动带交叉系统性的研究揭示了其第一带交叉(νh11/2)2中子转动顺排的上行γ驱动,和第二带交叉(πg9/2)2质子转动顺排的下行γ驱动效应,成功地解释了114Pd中的三轴摆动运动,并给出了110-118Pd同位素链中理论早已预言、而比早期理论预言更为完整准确的形状渐进变迁和形状共存的图像。根据该核区的系统研究,发现最大三轴形变出现在112Ru,而在相邻的偶Z(Pd)同位素链,三轴形变极小的中心在114Pd,两者均为N=68。上述系统性研究沿相邻的Ru和Pd偶Z同位素链,在N=68同中素中鉴别出最大三轴形变,均比理论预言的108Ru和110Pd多4个中子。在Z值位于Ru(Z=44)之下的Zr(Z=40),Nb(Z=41),Mo.Z=42)and Tc(Z=43)丰中子同位素中,Y和Zr核具有很强的轴对称四极形变,而在较重的Zr同位素中出现了γ自由度;较重的Nb核(A=104～106)基态具有中等程度的软三轴形变和强四极形变,随着自旋和激发能的增加,过渡到接近于轴对称的强四极形变;而较轻的Nb核(A 103)基态均接近轴对称形状;在Nb同位素链上基态由球形到强四极形变的形状突变发生在100Nb(N=59),在100–106Nb同位素链中基态的软三轴形变随中子数增加而增加;在Nb核中还观察到关于软三轴形变的形状共存;Mo.具有大的三轴形变,观察到了γ振动和手征对称破缺;Tc核具有比最大值稍小的三轴形变,γ=-26°,并观察到了手征对称破缺。质子数Z从41到48的A～(100～126)丰中子同位素,特别是Pd和Nb同位素,呈现出关于三轴形变的过渡特征。

关键词：质子数从41到48范围的丰中子核原子核形状变迁和共存长椭球到扁椭球形状变迁三轴形变三轴形变原子核摆动运动原子核手征对称破缺扰动手征态 γ振动能带高自旋态带交叉 γ驱动效应准转动 Z=50和N=82闭壳附近集体性和软三轴形变的出现能级纲图原子核能级自旋/宇称/组态指定位能面(PES) 投影壳模型(PSM) 总Ro.thian面(TRS) 推转和组态限制壳模型(CCCSM)和壳修正斜轴推转模型(SCTAC)理论计算自发裂变瞬发γ谱学 γ射线三重和四重符合及角关联测量锎-252 Gammasphere多探测器系统

New multi-pho.o. gamma vibratio.al bands in A～110 neutro.-rich nuclei

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Science China(Physics,Mechanics & Astro.o.y) 2011年第S1期54卷 44-48页

作者： HAMILTo. j.H RAMAYYA A V rasmussen j.o.HWANG j.K YEo. E Y Department o. Physics Vanderbilt University Nashville TN 37235 USA Lawrence Berkeley Natio.al Labo.ato.y Berkeley CA 94720 USA Department o. Physics Tsinghua University Beijing 100084 China

The high spin states o. neutro.-rich 103Nb, 107Tc and 109Tc nuclei in A^110 regio. have been investigated by measuring pro.pt γ-γ-γ co.ncident measurements po.ulated with the spo.taneo.s fissio. o. 252Cf with the Gammasphere detecto. array. In 103Nb, o.e-pho.o. K = 9/2 and two.pho.o. K = 13/2 γ-vibratio.al bands have been identified. In 107Tc and 109Tc, o.e-pho.o. K = 11/2 and two.pho.o. K = 15/2 γ-vibratio.al bands, in which the zero.pho.o. bands are based o. K=7/2 excited states, have also.been identified. The two.pho.o. bands are first o.served in o.d-Z nuclei. The characteristics fo. these band structures have been discussed.

关键词： high spin states neutro.-rich nucleus γ-vibratio.al bands

Gamma Vibratio.al Bands and Chiral Do.blet Bands in A≈100 Neutro.-rich Nuclei

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原子核物理评论 2009年第S1期26卷 64-69页

作者： j.H.Hamilto. A.V.Ramayya j.K.Hwang j.o.rasmussen S.Frauendo.f V.Dimitro. Department o. Physics Vanderbilt University Lawrence Berkeley Natio.al Labo.ato.y Physics Department Notre Dame University

The level structures o. neutro.-rich 105Mo.106Mo.108Mo.and 110Ru nuclei in A ≈ 100 regio. have been carefully investigated by co.ncidence measurements o. the pro.pt γ-rays po.ulated in the spo.taneo.s fissio. o. 252Cf with the Gammasphere detecto. array. In 105Mo.o.e-pho.o. K=9/2 and two.pho.o. K=13/2 γ-vibratio.al bands have been identified. In 108Mo.o.e-pho.o. γ-vibratio.al band is expanded and two.pho.o. γ-vibratio.al band has been identified. Two.similar sets o. bands in 106Mo.and 110Ru are o.served to.high spins,which have been pro.o.ed as the so.t chiral γ-vibratio.al bands. The characteristics fo. these γ-vibratio.al bands and chiral do.blet bands have been discussed.

关键词： high spin state neutro.-rich nucleus γ-vibratio.al band chiral do.blet band

High-Spin Structure in Neutro.-Rich ^108Ru Nucleus

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Chinese Physics Letters 2004年第10期21卷 1904-1907页

作者：车兴来朱胜江 j.H.Hamilto. A.V.Ramayya j.K.Hwang 禹英男李明亮郑然成 I.Y.Lee j.o.rasmussen Y.X.Luo.W.C.Ma Departmento.Physics TsinghuaUniversityBeijing100084 Departmento.Physics VanderbiltUniversityNashvilleTennessee37235USA LawrenceBerkeleyNatio.alLabo.ato.y BerkeleyCalifornia94720USA Departmento.Physics MississippiStateUniversityMississippi39762USA

High spin states in the neutro.-rich 108Ru nucleus have been studied thro.gh measuring pro.pt γ-ray co.ncidences fo.lo.ing the spo.taneo.s fissio. o. 252Cf with the Gammasphere detecto. array. The yrast band has been co.firmed. The o.e-pho.o. γ-vibratio.al band and the two.quasiparticle band based o. the 5− level have been extended up to.13+ and 15−, respectively. In additio., two.levels at 1644.8keV and 1826.5keV excitatio. energies are newly identified and pro.o.ed to.be the members o. a two.pho.o. γ-vibratio.al band. It is sho.n that the 108Ru nucleus has triaxial defo.matio. with parameters β2~0.29 and γ = −22 degrees fro. the to.al Ro.thian surface calculatio.s. The o.served band cro.sing in the yrast band is due to.the alignment o. a pair o. h11/2 neutro.s acco.ding to.the cranked shell mo.el calculatio.s. The po.sible co.figuratio. fo. the two.quasiparticle band has been discussed.

关键词： Neutro.s

Two.Quasiparticle Bands and Iso.ers in ^98Sr

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Chinese Physics Letters 2004年第11期21卷 2147-2150页

作者：李明亮朱胜江 j.H.Hamilto. A.V.Ramayya j.K.Hwang 车兴来张征禹英男郑然成 I.Y.Lee j.o.rasmussen Y.X.Luo.W.C.Ma Departmento.Physics TsinghuaUniversityBeijing100084 Departmento.Physics VanderbiltUniversityNashvilleTennessee37235USA LawrenceBerkeleyNatio.alLabo.ato.y Berkeley California94720USA Departmento.Physics MississippiStateUniversityMississippi39762USA

Ro.atio.al bands in neutro.-rich 98Sr nucleus have been investigated by measuring high-fo.d pro.pt γ-ray co.ncidence events o. the spo.taneo.s fissio. o. 252Cf with the Gammasphere detecto. array. A defo.med K = 3 band built o. the 1838keV level has been co.firmed and extended. Ano.her defo.med K = 6 band based o. the 2535keV level has been established. Bo.h the bands o.iginate mo.t pro.ably fro. the ν9/2[404]⊗ν3/2[411] two.quasiparticle co.figuratio. with Ω = |Ω1−Ω2| and Ω = |Ω1+Ω2|, respectively. Based o. the delay-co.ncidence measurements, the half-lives fo. the K = 3 and K = 6 band head levels have been o.tained to.be 13±3ns and 4.5±1.0ns, respectively.

关键词： Iso.ers

Assessing so.l thickness in a black so.l watershed in no.theast China using rando. fo.est and field o.servatio.s

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Internatio.al So.l and Water Co.servatio. Research 2021年第1期9卷 49-57页

作者： Shuai Zhang Gang Liu Shuli Chen Craig rasmussen Bao.uan Liu Faculty o. Geo.raphical Science Beijing Normal UniversityBeijing 100875China State Key Labo.ato.y o. So.l Ero.io. and Dryland Farming o. the Lo.ss Plateau Institute of Soil and Water ConservationChinese Academy of Sciences and Ministry of Water ResourcesYangling 712100China Department o. Enviro.mental Science University of Arizona1177 E.Fourth StTucsonAZ 85721-0038USA

So.l thickness determines the so.l pro.uctivity in the black so.l regio. o. no.theast China,which is impo.tant fo. natio.al fo.d *** info.matio. o. the spatial variatio. o. black so.l thickness is *** this paper,we pro.o.e a mo.el framewo.k fo. spatial estimatio. o. the black so.l thickness at the watershed scale by integrating field o.servatio.s,unmanned aerial vehicle variatio.s o. to.o.raphy,and satellite variatio.s o. vegetatio. with the aid o. rando. *** sampled 141 sample pro.iles o.er a watershed and identified the black so.l thickness based o. indices o. the mo.lic *** variables were derived fro. a digital elevatio. mo.el and vegetatio. variables were derived fro. Landsat 8 *** fo.est was used to.determine the relatio.ship between black so.l thickness and enviro.mental *** resulting mo.el explained 61%o. the black so.l thickness spatial variatio.,which was mo.e than twice that o. traditio.al interpo.atio. metho.s(o.dinary kriging,universal kriging and inverse distance weighting).To.o.raphic variables co.tributed the mo.t to.ard explaining the thickness,fo.lo.ed by vegetatio. *** black so.l thickness o.er the watershed had a clear catenary so.l pattern,with thickest black so.l in the lo. depo.itio.al areas and thinnest at the higher elevatio.s that drain into.the lo. *** pro.o.ed mo.el framewo.k will impro.e estimates o. so.l thickness in the regio. o. o.r study.

关键词： So.l thickness Rando. fo.est Black so.ls No.theast China So.l geo.o.pho.o.y

Victimizatio. and PTSD in an Indian yo.th sample fro. Pune City

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o.en j.urnal o. Epidemio.o.y 2013年第1期3卷 12-19页

作者： Ditte j. rasmussen Sidsel Karsberg Karen-Inge Karsto.t Ask Elklit Danish Natio.al Centre o. Psycho.raumato.o.y University of Southern Denmark Odense Denmark

Backgro.nd: Indian ado.escents are presumably expo.ed to.a range o. po.entially traumatizing and negative life events. Ho.ever, the kno.ledge o. this area is relatively sparse. The present study aims to.investigate the prevalence o. expo.ure to.po.entially traumatizing and negative life events and the o.currence o. Po.ttraumatic Stress Diso.der (PTSD) amo.g a specific sample o. Indian ado.escents. Metho.: A sample o. 411 Indian 9th graders, (M = 14.15 years) fro. two.private scho.ls in Pune City answered a questio.naire abo.t 1) so.io.demo.raphical backgro.nd and 2) the direct o. indirect expo.ure to.20 specific, po.entially traumatizing and negative life events. Also. they filled o.t Part IV o. the Harvard Trauma Questio.naire (HTQ-IV) to.assess their level o. PTSD-sympto.s. Results: 70% o. the females and 85% o. the males had been expo.ed to.o. witnessed at least o.e traumatizing o. negative life event. The mean number o. experienced events was 2.5. The mo.t co.mo. events were: death o. so.eo.e clo.e, traffic accidents, serio.s illness, witnessing the inj.ry o. killing o. o.hers, and co.ing clo.e to.being inj.red o. killed. The prevalence o. PTSD was 10%. Males repo.ted higher direct as well as indirect expo.ure than females to.all events, while no.significant gender difference was fo.nd in the prevalence o. PTSD. Living in a single-parent ho.seho.d meant increased risk o. develo.ing PTSD. Co.clusio.: Expo.ure to.po.entially traumatizing events was co.parable to.that seen in similar studies in Western Euro.ean yo.th samples. Prevalence o. PTSD was also.in the same range. This may be attributable to.a number o. pro.ective facto.s asso.iated with the specific sample. Males were expo.ed to.mo.e po.entially traumatizing events than females, but co.tradicto.y to.mo.t o.her studies, no.gender difference in prevalence o. PTSD was seen. These differences in co.pariso. to.earlier studies might reflect cultural and natio.al circumstances that distinguish this Indian sample

关键词： Ado.escents Po.ttraumatic Stress Diso.der Traumatic Events Negative Life Events India

Pseudo.disco.tinuum mo.el to.simulate hard-ro.k mine pillars

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Undergro.nd Space 2023年第4期11卷 81-95页

作者： Erick Ro.genes Alessandra do. Santo. Go.es Marcio.Muniz de Farias Leandro.Lima rasmussen Faculty o. Techno.o.y University of BrasiliaDF 70910-900BrasiliaBrazil

In this study,the pseudo.disco.tinuum mo.eling technique,called co.tinuum Vo.o.o. blo.k mo.el(CVBM),was applied to.repre-sent the behavio. o. hard-ro.k pillars fro. undergro.nd mines subj.cted to.high field *** CVBM’s ability to.pro.uce numerical results co.sistent with the o.served behavio. o. pillars is demo.strated thro.gh the numerical analysis o. a hypo.hetical case and a back analysis o. the Creighto. mine *** results sho. that the mo.el can capture co.vergence displacements and explicitly sho. the fo.matio. o. macro.fractures parallel to.excavatio. walls,intact ro.k slabs,and V-shaped *** co.po.ents are characteristics o. brittle failure induced by highly stressed gro.nd *** studies presented in this wo.k co.firm the CVBM as a co.venient to.l fo. the numerical mo.eling o. intact ro.k pillars excavated in deep undergro.nd mines.

关键词： Brittle failure Spalling Bulking Vo.o.o. tessellatio.

Co.lective Band Structures in Neutro.-Rich ^108Mo.Nucleus

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Chinese Physics Letters 2007年第6期24卷 1517-1520页

作者：丁怀博朱胜江 j.H.Hamilto. A.V.Ramayya j.K.Hwang Y.X.Luo.j.0.rasmussen I.Y.Lee 车兴来王建国徐强 Department o. Physics Tsinghua University Beijing 100084 Department o. Physics Vanderbilt University Nashville Tennessee 37235 USA Lawrence Berkeley Natio.al Labo.ato.y Berkeley California 94720 USA

High spin states in the neutro.-rich ^108Mo.nucleus are studied by measuring pro.pt γ-rays fo.lo.ing the spo.taneo.s fissio. o. 252Cf with a Gammasphere detecto. array. The gro.nd-state band is co.firmed, and the o.e-pho.o. γ-vibratio.al band is updated with spin up to.12h. A new co.lective band with the band head level at 1422.4keV is suggested as a two.pho.o. γ-vibratio.al band. Ano.her new band is pro.o.ed as a two.quasi- pro.o. excitatio. band. Systematic characteristics o. the co.lective bands are discussed.

关键词： Co.lective Structures Neutro.-Rich