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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.Hamilton J.O.Rasmussen A.V.Ramayya S.Frauendorf 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-Akopian A.V.Daniel Yu.Oganessian M.A.Stoyer R.Donangelo 马文超 Physics Department Vanderbilt University Lawrence Berkeley national Laboratory Department of Chemistry U.C.Berkeley Department of Physics University of Notre Dame Institut für Strahlenphysik FZD-Rossendorf Department of Physics Tsinghua University School of Science Huzhou Teachers College School of Physics Peking University Department of Physics and Astronomy Shanghai Jiao Tong University Institute of Modern Physics Chinese Academy of Sciences Chemistry Department University of Kentucky Physics Division Oak Ridge National Laboratory Flerov Laboratory for nuclear Reactions JINR Lawrence Livermore national Laboratory 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核具有大的三轴形变,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Routhian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

Chebyshev polynomial-based Ritz method for thermal buckling and free vibration behaviors of metal foam beams

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Applied Mathematics and Mechanics(English Edition) 2024年第5期45卷 891-910页

作者： n.D.nGUYEn t.n.nGUYEn Faculty of Civil Engineering Ho Chi Minh City University of Technology and EducationHo Chi Minh City 71309Viet Nam Faculty of Engineering and technology Kien Giang UniversityChau Thanh 92000Viet Nam

this study presents the Chebyshev polynomials-based Ritz method to examine the thermal buckling and free vibration characteristics of metal foam *** analyses include three models for porosity distribution and two scenarios for thermal *** material properties are assessed under two conditions,i.e.,temperature dependence and temperature *** theoretical framework for the beams is based on the higher-order shear deformation theory,which incorporates shear deformations with higher-order *** governing equations are established from the Lagrange equations,and the beam displacement fields are approximated by the Chebyshev *** simulations are performed to evaluate the effects of thermal load,slenderness,boundary condition(BC),and porosity distribution on the buckling and vibration behaviors of metal foam *** findings highlight the significant influence of temperature-dependent(tD)material properties on metal foam beams'buckling and vibration responses.

关键词： Ritz method Chebyshev function buckling vibration metal foam beam higher-order beam theory(HOBt)

tuning the particle size,physical properties,and photocatalytic activity of Ag_(3)PO_(4)materials by changing the Ag^(+)/PO_(4)^(3-)ratio

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Chinese Physics B 2023年第3期32卷 561-568页

作者： Hung n M Oanh L t M Chung D P thang D V Mai V t Hang L t Minh n V Center for nano Science and technology Hanoi National University of Education136 Xuan Thuy RoadCau Giay DistrictHanoi 100000Vietnam Department of Physics Hanoi National University of Education136 Xuan Thuy RoadCau Giay DistrictHanoi 100000Vietnam Hanoi University of Mining and Geology Duc Thang WardNorth Tu Liem DistrictHanoi 100000Vietnam Institute of Materials Science Vietnam Academy of Science and Technology18 Hoang Quoc VietHanoi 100000Vietnam Faculty of Basic Sciences Hanoi University of Natural Resources and Environment41 A Phu Dien RoadNorth Tu LiemHanoi 100000Vietnam

this study demonstrates the influence of the Ag^(+)/PO_(4)^(3-)ratio in precursor solution on the crystal structural formation,morphology,physical properties,and photocatalytic performance of a Ag_(3)PO_(4)photocatalyst that is fabricated,using a facile precipitation method,from AgnO_(3)and na2HPO_(4)·12H_(2)*** material characterizations were carried out using x-ray diffraction(XRD),scanning electron microscopy(SEM),energy-dispersive x-ray spectroscopy(EDX),Brunauer–Emmett–teller(BEt)surface area,Fourier transform infrared(FtIR)absorption,Raman scattering,x-ray photoelectron spectroscopy(XPS),UV-vis absorption,and photoluminescence(PL).the results show that Ag_(3)PO_(4)crystallizes better when the excess PO_(4)^(3-)content increases,and the lattice parameters decrease slightly,while the crystal diameter and the particle size *** change is also observed in the Raman scattering and FtIR spectra with the increase in the vibration frequency of the[PO_(4)]*** compression of the[PO_(4)]unit was also confirmed in the XPS spectra with the shift of P 2p peaks toward higher binding *** photocatalytic results showed that the samples synthesized from excess PO_(4)^(3-)solution exhibited higher photocatalytic performance compared to the sample with a Ag^(+)/PO_(4)^(3-)ratio of 3:1.A sample prepared from the precursor solution with a Ag^(+)/PO_(4)^(3-)ratio of 3:1.5 was optimal for RhB decomposition under both visible light and natural sunlight,completely decomposing 10 ppm RhB after 15 minutes of xenon lamp irradiation and after 60 minutes under solar light *** is attributed to the high crystallinity,small particle size and low electron–hole recombination rate of the sample.

关键词： morphology photocatalytic Ag^(+)/PO_(4)^(3-)ratio visible light

nonlinear-Optical Analogies in nuclear-Like Soliton Reactions:Selection Rules,nonlinear tunneling and Sub-Barrier Fusion–Fission

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Chinese Physics Letters 2024年第8期41卷 1-7页

作者： t.L.Belyaeva V.n.Serkin Universidad Autonoma del Estado de Mexico Av.Instituto Literario 100C.P.50000TolucaMexico Benemerita Universidad Autonoma de Puebla Av.4 Sur 104C.P.72001PueblaMexico

the main goal of our study is to reveal unexpected but intriguing analogies arising between optical solitons and nuclear physics,which still remain hidden from *** consider the main cornerstones of the concept of nonlinear optics of nuclear reactions and the well-dressed repulsive-core *** the base of this model,we reveal the most intriguing properties of the nonlinear tunneling of nucleus-like solitons and the soliton selfinduced sub-barrier transparency *** describe novel interesting and stimulating analogies between the interaction of nucleus-like solitons on the repulsive barrier and nuclear sub-barrier *** main finding of this study concerns the conservation of total number of nucleons(or the baryon number)in nuclear-like soliton *** show that inelastic interactions among well-dressed repulsive-core solitons arise only when a“cloud”of“dressing”spectral side-bands appears in the frequency spectra of the *** property of nucleus-like solitons is directly related to the nuclear density distribution described by the dimensionless small shape-squareness *** the Fourier spectra of nucleus-like solitons are similar to the nuclear form *** show that the nuclear-like reactions between well-dressed solitons are realized by“exchange”between“particle-like”side bands in their spectra.

关键词： solitons soliton nonlinear

numerical assessment of spacing–burden ratio to effective utilization of explosive energy

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International Journal of Mining Science and technology 2015年第2期25卷 291-297页

作者： Sazid Mohd Singh t.n. Mining Engineering Department King Abdulaziz University Department of Earth Sciences Indian Institute of Technology-Bombay

the spacing–burden(S/B) ratio plays significant role on rock fragmentation and proper utilization of explosive energy to minimize the undesirable *** S/B ratio generates fine fragments due to pressure rings coalescence of two blast holes,whereas boulder generations were observed above optimum S/B *** conditions are not acceptable because of wastage of explosive ***,to resolve this issue,a numerical model study was conducted to optimize the S/B ratio and to envisage its effect on rock fragmentation based on utilization of explosive *** element simulation tool was used to see the extent of two blast hole influence area variation with varying S/B *** better results were obtained at S/B ratio of 1:2 with optimum utilization of peak explosive *** performance was observed based on peak kinetic energy,peak pressure,radial and hoop stresses on centre of the two blast holes,where pressure rings coalescence.

关键词： Rock blasting Spacing-burden ratio (S/B)Rock fragmentation numerical modelling Pressure rings

An Ensemble Forecast of the South China Sea Monsoon

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Advances in Atmospheric Sciences 1999年第2期16卷 159-182页

作者： t.n.Krishnamurti Mukultewari EdBensman Department of Meteorology Florida State University Tallahassee Climate and Radiation Branch Code 913 NASA Goddard Space Flight Center Greenbelt

this paper presents a generalized ensemble forecast procedure for the tropical latitudes. Here we propose an empirical orthogonal function-based procedure for the definition of a seven-member ensemble. the wind and the temperature fields are perturbed over the global tropics. Although the forecasts are made over the global belt with a high-resolution model, the emphasis of this study is on a South China Sea monsoon. Over this domain of the South China Sea includes the passage of a tropical Storm, Gary, that moved eastwards north of the Philippines. the ensemble forecast handled the precipitation of this storm reasonably well. A global model at the resolution triangular truncation 126 waves is used to carry out these seven forecasts. the evaluation of the ensemble of forecasts is carried out via standard root mean square errors of the precipitation and the wind fields. the ensemble average is shown to have a higher skill compared to a control experiment, which was a first analysis based on operational data sets over both the global tropical and South China Sea domain. All of these experiments were subjected to physical initialization which provides a spin-up of the model rain close to that obtained from satellite and gauge-based estimates. the results furthermore show that inherently much higher skill resides in the forecast precipitation fields if they are averaged over area elements of the order of 4° latitude by 4° longitude squares.

关键词： Ensemble forecast triangular truncation

Bound States Energies of a Harmonic Oscillator Perturbed by Point Interactions

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Communications in theoretical Physics 2017年第3期67卷 241-249页

作者： n.Ferkous t.Boudjedaa Laboratory of theoretical Physics Department of Physics University of Jijel PB 98 Ouled Aissa DZ-18000 Jijel Algeria

We determine explicitly the exact transcendental bound states energies equation for a one-dimensional harmonic oscillator perturbed by a single and a double point interactions via Green's function techniques using both momentum and position space representations. the even and odd solutions of the problem are discussed. the corresponding limiting cases are recovered. For the harmonic oscillator with a point interaction in more than one dimension,divergent series appear. We use to remove this divergence an exponential regulator and we obtain a transcendental equation for the energy bound states. the results obtained here are consistent with other investigations using different methods.

关键词： Green's function delta potential harmonic oscillator regularization

Multisubband electron mobility in a parabolic quantum well structure under the influence of an applied electric field

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Journal of Semiconductors 2014年第1期35卷 1-6页

作者： n.Sahoo t.Sahu Department of Electronic Science Berhampur University Department of Electronics and Communication Engineering National Institute of Science and Technology

We study the multisubband electron mobility in a barrier delta doped AlχGal-χAs parabolic quantum well structure under the influence of an applied electric field perpendicular to the interface plane. We consider the alloy fraction χ = 0.3 for barriers and vary x from 0.0 to 0.1 for the parabolic well. Electrons diffuse into the well and confine within the triangular like potentials near the interfaces due to Coulomb interaction with ionized donors. the parabolic structure potential, being opposite in nature, partly compensates the Coulomb potential. the external electric field further amends the potential structure leading to an asymmetric potential profile. Accordingly the energy levels, wave functions and occupation of subbands change. We calculate low temperature electron mobility as a function of the electric field and show that when two subbands are occupied, the mobility is mostly dominated by ionised impurity scattering mediated by intersubband effects. As the field increases transition from double subband to single subband occupancy occurs. A sudden enhancement in mobility is obtained due to curtailment of intersubband effects. thereafter the mobility is governed by both impurity and alloy disorder scatterings. Our analysis of mobility as a function of the electric field for different structural parameters shows interesting results.

关键词： parabolic quantum well multisubband electron mobility AlGaAs

Effects of Heat treatment on Hardness and Dry Wear Properties of a Semi-Solid Processed Fe-27 wt pct Cr-2.9 wt pct C Cast Iron

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Journal of Materials Science & technology 2008年第3期24卷 330-334页

作者： A.Wiengmoon t.Chairuangsri n.Chomsang n.Poolthong J.t.H.Pearce Department of Physics Faculty of ScienceNaresuan University Department of Industrial Chemistry and Electron Microscopy Research and Service Center Faculty of ScienceChiang Mai University Department of Physics Faculty of ScienceChiang Mai University Division of Materials technology School of EnergyEnvironmental and MaterialsKing Mongkut's University of Technology Thonburi national Metal and Materials technology Center

EfFects of heat treatments on hardness and dry wear properties of a semi-solid processed Fe-26.96 wt pct Cr- 2.91 wt pct C cast iron were studied. Heat treatments included tempering at 500℃, destabilisation at 1075℃ and destabilisation at 1075℃ plus tempering at 500℃, all followed by air cooling. Electron microscopy revealed that, in the as-cast condition, the primary proeutectic austenite was round in shape while the eutectic M7C3 carbide was found as radiating clusters mixed with directional clusters. tempering did not change the microstructure significantly when observed by scanning or transmission electron microscopy. Destabilisation followed by air cooling led to a precipitation of secondary M23C6 carbide and a transformation of the primary austenite to martensite. Precipitation behaviour is comparable to that observed in the conventionally cast iron. tempering after destabilisation resulted in a higher amount of secondary carbide precipitation within the tempered martensite in the eutectic structure. Vickers macrohardness and microhardness in the proeutectic zones were measured. Dry wear properties were tested by using a pin-on-disc method. the maximum hardness and the lowest dry wear rate were obtained from the destabilisation-plus-tempering heat treatment due to the precipitation of secondary carbides within the martensite matrix and a possible reduction in the retained austenite.

关键词： Semi-solid process High chromium cast iron Heat treatment Hardness Wear