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Influence of High-Pressure Induced Lattice Dislocations and Distortions on Thermoelectric Performance of Pristine SnTe

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Chinese physics Letters 2024年第5期41卷 61-68页

作者：郑博文陈涛孙海瑞杨曼曼杨兵超陈欣张永胜刘晓兵 Laboratory of High-Pressure physics and Materials Science School of Physics and Physical EngineeringQufu Normal UniversityQufu 273165China Advanced Research Institute of Multidisciplinary Sciences Qufu Normal UniversityQufu 273165China Key Lab of Photovoltaic and Energy Conservation Materials Institute of Solid State physics HFIPSChinese Academy of SciencesHefei 230031China university of Science and Technology of china Hefei 230026China School of Electronic Engineering Huainan normal university Huainan 232038China

As a sister compound of PbTe, SnTe possesses the environmentally friendly elements. However, the pristine SnTe compounds suffer from the high carrier concentration, the large valence band offset between the L and Σpositions and high thermal conductivity. Using high-pressure and high-temperature technology, we synthesized the pristine SnTe samples at different pressures and systemically investigated their thermoelectric properties.High pressure induces rich microstructures, including the high-density dislocations and lattice distortions, which serve as the strong phonon scattering centers, thereby reducing the lattice thermal conductivity. For the electrical properties, pressure reduces the harmful high carrier concentration, due to the depression of Sn vacancies.Moreover, pressure induces the valence band convergence, reducing the energy separation between the L and Σpositions. The band convergence and suppressed carrier concentration increase the Seebeck coefficient. Thus, the power factors of pressure-sintered compounds do not deteriorate significantly under the condition of decreasing electrical conductivity. Ultimately, for a pristine SnTe compound synthesized at 5 GPa, a higher ZT value of 0.51 is achieved at 750 K, representing a 140% improvement compared to the value of 0.21 obtained using SPS. Therefore, the high-pressure and high-temperature technology is demonstrated as an effectively approach to optimize thermoelectric performance.

关键词： coefficient properties positions

Different coalescence sources of light nucleus production in Au-Au collisions at √sNN=3 GeV

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Chinese physics C 2024年第5期48卷 160-179页

作者：王瑞芹吕济鹏李彦豪宋军邵凤兰 School of physics and Physical Engineering Qufu Normal UniversityQufu 273165China School of Physical Science and Intelligent Engineering Jining UniversityJining 273155China

We study the production of light nuclei in the coalescence mechanism of Au-Au collisions at midrapidity at √sNN=3GeV.We derive analytic formulas of the momentum distributions of two bodies,three bodies,and four nucleons coalescing into light nuclei and naturally explain the transverse momentum spectra of the deuteron(d),triton(t),helium-3(3He),and helium-4(4He).We reproduce data on the yield rapidity densities,yield ratios,and averaged transverse momenta of d,t,3He,and 4He and provide the proportions of contributions from different coalescence sources for t,3He,and 4He in their production.We find that besides nucleon coalescence,nucleon+nucleus coalescence and nucleus+nucleus coalescence may play requisite roles in light nucleus production in Au-Au collisions at √sNN=3 GeV.

关键词： light nucleus production the coalescence model relativistic heavy ion collision

Strong-coupling superconductivity with Tc above 70 K in Be-decorated monolayer T-graphene

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Science china(physics,Mechanics & Astronomy) 2024年第1期67卷 99-105页

作者： Liu Yang Peng-Fei Liu Hao-Dong Liu Ya-Ping Li Na Jiao Hong-Yan Lu Bao-Tian Wang Ping Zhang School of physics and Physical Engineering Qufu Normal UniversityQufu 273165China Institute of High Energy physics Chinese Academy of SciencesBeijing 100049China Spallation Neutron Source Science Center Dongguan 523803China Institute of Applied physics and Computational Mathematics Beijing 100088China

Using first-principles calculations,we predict a new type of two-dimensional(2D)beryllium(Be)-decorated T-graphene named BeC_(2),where Be atoms are inserted into C–C bonds linking the carbon tetrarings of T-graphene.The band structure shows that BeC_(2)is metallic,thus,the possible phonon-mediated superconductivity is explored based on the Eliashberg equation.The calculated electron-phonon coupling(EPC)constantλis up to 4.07,and the corresponding superconducting critical temperature(Tc)is 72.1 K,approaching the liquid nitrogen temperature.The reason for the high Tc is the strong EPC.And it is proved to be an anisotropic single-gap superconductor by analyzing the superconducting gap?kof BeC_(2).The electronic susceptibility calculation shows strong nesting effect in BeC_(2).Since rare 2D superconductors show such a strong EPC constantλwhich originates from the coupling between electrons in C-pzorbital and in-plane vibrations of Be and C atoms,the predicted BeC_(2)provides a new platform for investigating strong EPC 2D superconductor.

关键词： two-dimensional carbon-based superconductor electron-phonon coupling strong coupling high superconducting critical temperature

Left Frobenius Pairs,Cotorsion Pairs and Weak Auslander-Buchweitz Contexts in Triangulated Categories

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Algebra Colloquium 2024年第2期31卷 285-308页

作者： Xin Ma Tiwei Zhao Zhaoyong Huang Nanqing Ding College of Science Henan University of EngineeringZhengzhou 451191China School of Mathematical Sciences Qufu Normal University QufuShandong 273165China department of Mathematics Nanjing UniversityNanjing 210093China 不详

Let T be a triangulated category with a proper classξof triangles.We introduce the notions of left Frobenius pairs,left(n-)cotorsion pairs and left(weak)Auslander-Buchweitz contexts with respect toξin T.We show how to construct left cotorsion pais from left n-cotorsion pairs,and establish a one-to-one correspondence between left Frobenius pairs and left(weak)Auslander-Buchweitz contexts.Some applications are given in the Gorenstein homological theory of triangulated categories.

关键词： left Frobenius pairs left n-cotorsion pairs left(weak)Auslander-Buchweitz contexts homological dimensions

Non-Gaussian quantum states generated via quantum catalysis and their statistical properties

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Chinese physics B 2024年第4期33卷 332-337页

作者：张晓燕杨春燕王继锁孟祥国 Shandong Provincial Key Laboratory of Laser Polarization and Information Technology School of Physics and Physical EngineeringQufu Normal UniversityQufu 273165China Shandong National Secondary Vocational School Qingzhou 262500China School of Basic Medical Sciences Weifang Medical UniversityWeifang 261000China

A new kind of non-Gaussian quantum catalyzed state is proposed via multiphoton measurements and two-mode squeezing as an input of thermal state.The characteristics of the generated multiphoton catalysis output state depends on the thermal parameter,catalyzed photon number and squeezing parameter.We then analyze the nonclassical properties by examining the photon number distribution,photocount distribution and partial negativity of the Wigner function.Our findings indicate that nonclassicality can be achieved through the implementation of multiphoton catalysis operations and modulated by the thermal parameter,catalyzed photon number and squeezing parameter.

关键词： two-mode squeezing multiphoton catalysis nonclassicality Wigner function

Masting promotes transformation from predation to mutualism in an oak-weevil-rodent system

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Science china(Life Sciences) 2024年第7期67卷 1514-1524页

作者： Hongmao Zhang Hongyu Niu Michael ASteele Liqing Peng Huimin He Aoqiang Li Xianfeng Yi Hongjun Li Zhibin Zhang Institute of Evolution and Ecology School of Life SciencesCentral China Normal UniversityWuhan 430079China State Key Laboratory of Integrated Management of Pest Insects and Rodents in Agriculture Institute of ZoologyChinese Academy of SciencesBeijing 100101China department of Biology Wilkes UniversityWilkes-Barre 18766USA School of Life Sciences Qufu Normal UniversityQufu 273165China

The significance of ecological non-monotonicity(a function whose first derivative changes signs)in shaping the structure and functions of the ecosystem has recently been recognized,but such studies involving high-order interactions are rare.Here,we have proposed a threetrophic conceptual diagram on interactions among trees,rodents,and insects in mast and non-mast years and tested the hypothesis that oak(Quercus wutaishanica)masting could result in increased mutualism and less predation in an oak-weevil-rodent system in a warm temperate forest of china.Our 14-year dataset revealed that mast years coincided with a relatively low rodent abundance but a high weevil abundance.Masting not only benefited seedling recruitment of oaks through increased dispersal by rodents but also a decrease in predation by rodents and weevils,as well as an increase in the overwintering survival of rodents.Masting appeared to have increased weevil survival by reducing predation of infested acorns by rodents.These results suggest that masting benefits all participants in the plant-insect-rodent system by increasing mutualism and reducing predation behavior(i.e.,a non-monotonic function).Our study highlights the significance of masting in maintaining the diversity and function of the forest ecosystem by facilitating the transformation from predation to mutualism among trophic species.

关键词： antagonism ecological non-monotonicity mutualism seed-weevil-rodent system seedling recruitment rodent overwintering survival weevil survival

Relationships among Sedentary Time,Electronic Product Addiction,and Depression in Adolescents during the COVID-19 Epidemic:A Cross-Lagged Study

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International Journal of Mental Health Promotion 2024年第3期26卷 221-228页

作者： Feng Sheng Chen Kong Chao Li Teaching department of Sports Qufu Normal UniversityQufu273165China Teaching department of Sports Shandong Management UniversityJinan250100China General Education Center Weifang Vocational CollegeWeifang262737China

Objective:This study was conducted to explore the relationships among sedentary behavior(SB),electronic product addiction(EPA),and depression(D)in adolescents during the COVID-19 epidemic.Methods:A total of 604 adolescents(including 309 girls and 295 boys aged 12-18)were selected from qufu City,Shandong Province,china for three rounds of investigation.The model was constructed using AMOS 23.0 software,and cross-lagged analysis was conducted.Results:SB at T1 can significantly positively predict SB and EPA at T2(p<0.05).EPA at T1 can significantly positively predict SB and D at T2(p<0.05).Physical activity level and SB at T2 can significantly predict SB and EPA at T3(p<0.05).EPA at T2 can significantly predict SB,EPA,and D at T3(p<0.05).Conclusions:SB and EPA are predictive factors for D.Moreover,SB can significantly positively predict D and indirectly predict D through the mediating effect of EPA.

关键词： COVID-19 electronic product addiction depression sedentary behavior

Interlayer Magnetic Interaction in the CrI_(3)/CrSe_(2) Heterostructure

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Chinese physics Letters 2024年第5期41卷 85-89页

作者：王秋皓倪美燕李淑静郑法伟路洪艳张平 School of physics and Physical Engineering Qufu Normal UniversityQufu 273165China Center for Quantum physics Key Laboratory of Advanced Optoelectronic Quantum Architecture and MeasurementSchool of PhysicsBeijing Institute of TechnologyBeijing 100081China Beijing Key Lab of Nanophotonics and Ultrafine Optoelectronic Systems School of PhysicsBeijing Institute of TechnologyBeijing 100081China College of Mathematics and physics Beijing University of Chemical TechnologyBeijing 100029China Institute of Applied physics and Computational Mathematics Beijing 100088China

Based on first-principles calculations, we systematically study the stacking energy and interlayer magnetic interaction of the heterobilayer composed of CrI_(3) and CrSe_(2) monolayers. It is found that the stacking order plays a crucial role in the interlayer magnetic coupling. Among all possible stacking structures, the AA-stacking is the most stable heterostructure, exhibiting interlayer antiferromagnetic interactions. Interestingly, the interlayer magnetic interaction can be effectively tuned by biaxial strain. A 4.3% compressive strain would result in a ferromagnetic interlayer interaction in all stacking orders. These results reveal the magnetic properties of CrI_(3)/CrSe_(2) heterostructure, which is expected to be applied to spintronic devices.

关键词： strain stacking interlayer

Angle-resolved photoemission study of NbGeSb with non-symmorphic symmetry

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Chinese physics B 2024年第2期33卷 464-470页

作者：马欢谭宁吴徐传李满王义炎路洪艳夏天龙王善才 department of physics Key Laboratory of Quantum State Construction and Manipulation(Ministry of Education)Renmin University of ChinaBeijing 100872China Beijing Key Laboratory of Opto-Electronic Functional Materials&Micro-Nano Devices Renmin University of ChinaBeijing 100872China School of Information Network Security People’s Public Security University of ChinaBeijing 100038China Institute of Physical Science and Information Technology Anhui UniversityHefei 230601China School of physics and Physical Engineering Qufu Normal UniversityQufu 273165China

We investigate the electronic structure of NbGeSb with non-symmorphic symmetry.We employ angle-resolved photoemission spectroscopy(ARPES)to observe and identify the bulk and surface states over the Brillouin zone.By utilizing high-energy photons,we identify the bulk Fermi surface and bulk nodal line along the direction X–R,while the Fermi surface of the surface state is observed by using low-energy photons.We observe the splitting of surface bands away from the high-symmetry point X.The density functional theory calculations on bulk and 1 to 5-layer slab models,as well as spin textures of NbGeSb,verify that the band splitting could be attributed to the Rashba-like spin–orbit coupling caused by space-inversion-symmetry breaking at the surface.These splitted surface bands cross with each other,forming two-dimensional Weyl-like crossings that are protected by mirror symmetry.Our findings provide insights into the two-dimensional topological and symmetry-protected band inversion of surface states.

关键词： non-symmorphic symmetry nodal line splitting of surface bands angle-resolved photoemission spectroscopy