检索结果-南通市图书馆

Chinese physics B 2013年第10期 567-570页

作者：郑龙吴小山 Laboratory of Solid State Microstructures and department of physics Nanjing University

X-ray absorption spectra(XAS) at Mn K-edge and Fe K-edge in LaMn1-x Fe x O3show that with the increase of Fe substitution the chemical valence of Mn4+decreases,while the chemical valence of Fe3+remains *** distortions,such as the rotating and tilting for oxygen octahedron in the unit cell vary with iron content.A phase transition occurs at the Fe content values of 0.2～*** evolutions of rotation and tilting angle of FeO6/MnO6octahedral may be the vital factors to the structure and *** believe that the spin configuration of Fe3+may vary from the intermediate spin t42g e1g(S = 3/2) to the higher spin t32g e2g(S = 5/2) near the phase transition.

关键词： structural distortion X-ray absorption phase transition

Implementation Multi Representation and Oral Communication Skills in department of physics Education on Elementary physics II

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

材料科学与工程（中英文A版） 2015年第1期5卷 60-64页

作者： Intan Kusumawati Putut Marwoto Suharto Linuwih department of physics Education High School in Teaching and Education (STKIP) Singkawang Singkawang 79251 West Borneo department of physics Education State University ofSemarang (Unnes) Semarang 50233 Central Java

The ability of multi representation has been widely studied, but there has been no implementation through a model of learning. This study aimed to determine the ability of the students multi representation, relationships of multi representation capabilities and oral communication skills, as well as the application of the relations between the two capabilities through learning model Presentatif Based on Multi representation (PBM) in solving optical geometric (Elementary physics II). A concurrent mixed method was used with qualitative-quantitative methods. Means of collecting data in the form of the pre-test and post-test are essay form, observation sheets of oral communication skills, and assessment of learning by observation sheet PBM learning models, they all have a high degree of validity category, which is 3.91, 4.22, 4.13, and 3.88, respectively. Test reliability with Alpha Cronbach technique, the reliability coefficient is 0.494. The students are in department of physics Education Unnes as a research subject. Sequence multi representation tendency of students from high to low in sequence, representation of M, D, G, V; whereas the order of accuracy, the group representation V, D, G, M. Relationship of multi representation ability and oral communication skills are comparable/proportional. Implementation of conjunction can generate grounded theory. This study should be applied to the physics of matter, or any other university for comparison.

关键词：物理教育基础物理口头表达能力可靠性系数表现能力学习模式口语定性定量方法

The Emergence of Modern physics Research in China:The Yenching department of physics and the Rockefeller Foundation

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Annals of History of Science and Technology 2019年第2期3卷 4-61页

作者： Danian Hu department of History The City College of The City University of New YorkNew YorkNY 10031US

Based on archival materials discovered in America,Britain,and China,this paper carefully examines the history of the short-lived and completely overlooked department of physics in the Premedical School of Peking Union Medical College(PUMC),and uncovers this department’s extensive interconnections with its counterpart at Yenching *** project also looks into the Master of Science(MS)program in the department of physics at Yenching University,which,founded in 1927,was the first graduate program in physics in *** was this MS program that transformed the Yenching department from a largely premedical training center serving the PUMC into a prominent cradle of Chinese physics *** Yenching department,despite its small faculty and brief existence,nurtured many eminent Chinese physicists,such as Chao-Ying Meng孟昭英,Wen-Yu Chang张文裕,Ming-Chen Wang王明贞,Chia-Liu Luke Yuan袁家骝,Cheng-Shu Wang(Chang)王承书,Ho-Fu Lu卢鹤绂,Ting-Sui Ke葛庭燧,Kun Huang黄昆,and Chia-Lin Hsieh谢家麟.It would have been impossible to achieve these outstanding accomplishments without the effective leadership and pioneering work of ***,***,***,and ***—the first four department Chairs—in combination with relatively abundant private funding,mostly from America,and extensive educational connections with Western *** paper not only introduces in detail these four department heads and their contributions,but also discloses the unique role played by the Rockefeller Foundation via the China Medical Board and the PUMC in the development of the Yenching department of physics.

关键词： The Premedical School of the Peking Union Medical College the department of physics at Yenching University the China Medical Board the Rockefeller Foundation William Warren Stifler(1883–1954) Charles Hodge Corbett(1881–1963) Paul Alexander Anderson(1898–1990) Yu-Ming Hsieh(1895–1986) William Band(1906–1993)

维普期刊数据库

Testing the first law of black hole mechanics with gravitational waves

在线全文

学校读者我要写书评

暂无评论

Science China(physics,Mechanics & Astronomy) 2024年第10期Mechanics & Astronomy) .卷 80-86页

作者： Chao-Wan-Zhen Wang Jin-Bao Zhu Guo-Qing Huang Fu-Wen Shu department of physics Nanchang University Center for Relativistic Astrophysics and High Energy physics Nanchang University GCAP-CASPER Physics DepartmentBaylor University

The successful observation of gravitational waves has provided humanity with an additional method to explore the universe, particularly black holes. In this study, we utilize data from LIGO and Virgo gravitational wave observations to test the first law of black hole mechanics, employing two different approaches. We consider the secondary compact object as a perturbation to the primary black hole before the merger, and the remnant black hole as a stationary black hole after the merger. In the pre-merger and post-merger analysis, our results demonstrate consistency with the first law, with an error level of approximate 25% at a68% credibility level for GW190403 051519. In the full inspiral-merger-ringdown analysis, our results show consistency with the first law of black hole mechanics, with an error level of about 6% at a 68% credibility level and 10% at a 95% credibility level for GW191219 163120. Additionally, we observe that the higher the mass ratio of the gravitational wave source, the more consistent our results are with the first law of black hole mechanics. Overall, our study sheds light on the nature of compact binary coalescence and their implications for black hole mechanics.

关键词： gravitational waves black hole mechanics data analysis ringdown

同方期刊数据库

Injection of a Self-propelled Polymer into a Small Circular Cavity

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Polymer Science 2024年第6期42卷 886-894页

作者： Chao Wang Yan-Li Zhou Xiao Yang Fan Wu Meng-Bo Luo department of physics Taizhou UniversityTaizhou318000China department of physics Zhejiang UniversityHangzhou310027China

The injection of a polymer chain into a small circular cavity under tangential self-propelled force is studied by using Langevin dynamics *** indicate that the injection dynamics of the active polymer shows strong correlation with the polymer conformation inside the cavity depending on the polymer rigidity(k_(b)).The injection timeτvaries nonmonotonously with increasing k_(b),and reaches its minimum at k_(b)^(*).When k_(b) is small(k_(b)≪k_(b)^(*)),the polymer is nearly random coil in the cavity,and spends a long time at the final stage of the injection process due to the large repulsion between monomers inside the *** k_(b) is moderate(k_(b)∼k_(b)^(*)),the part of polymer inside the cavity forms spiral configuration under the tangential active force,and the whole polymer moves synchronously with a constant velocity during the injection process,leading to a small injection *** k_(b) is large(k_(b)≫k_(b)^(*)),the polymer is nearly straight at the initial stage of the injection process,and takes a long time to bend itself,leading to a large injection time.

关键词： Active Polymer Injection Dynamics Simulation

维普期刊数据库

Domain wall network:A dual solution for gravitational waves and Hubble tension?

在线全文

学校读者我要写书评

暂无评论

Science China(physics,Mechanics & Astronomy) 2024年第11期Mechanics & Astronomy) .卷 43-50页

作者： Ligong Bian Shuailiang Ge Changhong Li Jing Shu Junchao Zong department of physics and Chongqing Key Laboratory for Strongly Coupled physics Chongqing University Center for High Energy physics Peking University School of physics and State Key Laboratory of Nuclear physics and Technology Peking University department of Astronomy Key Laboratory of Astroparticle Physics of Yunnan Province School of Physics and AstronomyYunnan University Beijing Laser Acceleration Innovation Center department of physics Nanjing University CAS Key Laboratory of Theoretical physics Institute of Theoretical Physics Chinese Academy of Sciences

We explore the possibility that domain wall networks generate the stochastic gravitational wave background（SGWB） observed as a strong common power-law process in the Data Release-2 of Parkes Pulsar Timing Array. We find that a broad range of parameters, specifically wall tension around σDW～（29-414 TeV）3and wall-decay temperature within Td～ 20-257 MeV, can explain this phenomenon at a 68% credible level. Meanwhile, the same parameters could ease the Hubble tension if particles from these domain wall networks decay into dark radiation. We establish a direct analytical relationship, ?GW（fp, T0）h2～ ?radh2(?ν?Neff)2,to illustrate this coincidence, underlining its importance in the underlying physics and potential applicability to a wider range of models and data. Conversely, if the common power-law process is not attributed to domain wall networks, our findings impose tight limits on the wall tension and decay temperature.

关键词： domain wall gravitational waves Hubble tension

同方期刊数据库

Holographic superfluid ring with a weak link

在线全文

学校读者我要写书评

暂无评论

Science China(physics,Mechanics & Astronomy) 2024年第11期Mechanics & Astronomy) .卷 33-42页

作者： Zhi-Hong Li Huai-Fan Li department of physics Shanxi Datong University Institute of Theoretical physics Shanxi Datong University

We explore the generation of topological defects in the course of a dynamical phase transition in a ring with a weak link, i.e., a SSS Josephson junction, from the AdS/CFT correspondence. By setting different parameters of the junction(width, steepness,depth) and the final temperature of the quench, the configurations of the charge density and condensate of the order parameters of the dual field theory are presented. Meanwhile, we observe that in the final equilibrium state, variations in parameters of the junctions only affect the configurations of the charge density and condensate of the order parameters, without altering their values outside the junction. However, variations in the final temperature will directly affect the values of the charge density and condensate of the order parameters outside of the junction. Moreover, in the final equilibrium state, we propose an analytic relation between the gauge-invariant velocity in the two superconducting states in the SSS Josephson junction, which agrees well with the numerical results.

关键词： AdS/CFT correspondence holographic superfluid holographic Josephson junction

同方期刊数据库

Consistency between domain wall oscillation modes and spin wave modes in nanostrips

在线全文

学校读者我要写书评

暂无评论

Chinese physics B 2024年第6期33卷 511-516页

作者：董新伟吴振江 department of physics and Institute of Theoretical physics and Astrophysics Xiamen UniversityXiamen 361005China

Investigations on domain wall(DW) and spin wave(SW) modes in a series of nanostrips with different widths and thicknesses have been carried out using micromagnetic simulation. The simulation results show that the frequencies of SW modes and the corresponding DW modes are consistent with each other if they have the same node number along the width direction. This consistency is more pronounced in wide and thin nanostrips, favoring the DW motion driven by *** analysis of the moving behavior of a DW driven by SWs is also carried out. The average DW speed can reach a larger value of ~ 140 m/s under two different SW sources. We argue that this study is very meaningful for the potential application of DW motion driven by SWs.

关键词： micromagnetic simulation domain wall spin wave

维普期刊数据库

Tidal effects based on a GUP-induced effective metric

在线全文

学校读者我要写书评

暂无评论

Communications in Theoretical physics 2024年第9期76卷 65-74页

作者： Soon-Tae Hong Yong-Wan Kim Young-Jai Park Center for Quantum Spacetime and department of physics Sogang University department of physics and Research Institute of physics and Chemistry Jeonbuk National University department of physics Sogang University

In this paper, we study tidal forces in the Schwarzschild black hole, whose metric explicitly includes a generalized uncertainty principle(GUP) effect. We also investigate interesting features of the geodesic equations and tidal effects that are dependent on the GUP parameter αrelated to a minimum length. Then, by solving the geodesic deviation equations explicitly with appropriate boundary conditions, we show that α in the effective metric affects both the radial and angular components of the geodesic equation, particularly near the singularities.

关键词： effective metric generalized uncertainty principle geodesic deviation equation

4He monolayer on graphene: a quantum Monte Carlo study

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Communications in Theoretical physics 2024年第9期76卷 151-159页

作者： S Yu M Boninsegni department of physics University of Alberta

We revisit the problem of adsorption of a single4He layer on graphene, focusing on the commensurate(C1/3) crystalline phase, specifically on whether it may possess a nonzero superfluid response, and on the existence of superfluid phases, either（metastable） liquid or vacancy-doped crystalline. We make use of canonical quantum Monte Carlo simulations at zero and finite temperature, based on a realistic microscopic model of the system. Our results confirm the absence of any superfluid response in the commensurate crystal, and that no thermodynamically stable uniform phase exists at lower coverage. No evidence of a possibly long-lived, metastable superfluid phase at C1/3coverage is found. Altogether, the results of ground-state projection methods and finite-temperature simulations are entirely consistent.

关键词： helium low-dimensional systems quantum Monte Carlo superfluidity supersolids