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Pyroelectric spectrum in Pb(zr,Sn,Ti)O3 antiferroelectric- ferroelectric ceramics

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Chinese Science Bulletin 2000年第13期45卷 1169-1172页

作者： Feng, YJ xu, z Yang, TQ Yao, X Xian Jiao Tong Univ Elect Mat Res Lab Xian 710049 Peoples R China

The pyroelectric effect of phase transition induced with temperature in Nb-modified Pb(zr,Sn,Ti)O3 antiferroelectric-ferroelectric ceramics is studied. Experimental results reveal that the phase transitions are accompanied with marked pyroelectric peaks, there exists the close relation between the type of phase transition and the shape of pyroelectric peak. Because of the variations of phase transition, various pyroelectric spectra result. The pyroelectric spectrum can display the polarization effect and some inferior phase transitions with temperature variations, such as antiferroelectric AFEA-AFEB or ferroelectric FEL-FEH transition, which are not detected by the conventional dielectric measurement.

关键词： Pb(zr Sn Ti)O3 ceramics pyroelectric spectrum temperature-induced phase transition.

NUMERICAL STUDY OF TURBULENT IMPINGING JET WITH A REFINED k-ε MODEL

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Journal of Hydrodynamics 2000年第4期12卷 8-15页

作者： xu, J.L. xu, z. Huang, S.J. zhang, K.Y. Xiao, M. 2nd Dep. Nanjing Univ. of Aeron. and Astron. Nanjing 210016 China

A refined k-Ε model re-considering the fluctuating pressure diffusion term in the dissipation rate equation (Ε-equation) is provided and used in the numerical study of circular semi-confined turbulent impinging jet. The results are compared with those of the standard k-Ε model and show that the predicting ability of the refined k-Ε model is much improved, especially for the turbulent kinetic energy k. So it is necessary to consider the effect of the fluctuating pressure diffusion term and to model this term correctly and exactly in the near wall region with the great adverse pressure gradient, where the effect of the pressure fluctuating is important. Therefore we can conclude that the new modeling idea expressed in this paper is correct and effective.

关键词： Computer simulation Jets Mathematical models Turbulence

STCF conceptual design report (Volume 1): Physics & detector

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Frontiers of physics 2024年第1期19卷 1-154页

作者： M.Achasov X.C.Ai L.P.An R.Aliberti Q.An X.z.Bai Y.Bai O.Bakina A.Barnyakov V.Blinov V.Bobrovnikov D.Bodrov A.Bogomyagkov A.Bondar I.Boyko z.H.Bu F.M.Cai H.Cai J.J.Cao Q.H.Cao X.Cao z.Cao Q.Chang K.T.Chao D.Y.Chen H.Chen H.X.Chen J.F.Chen K.Chen L.L.Chen P.Chen S.L.Chen S.M.Chen S.Chen S.P.Chen W.Chen X.Chen X.F.Chen X.R.Chen Y.Chen Y.Q.Chen H.Y.Cheng J.Cheng S.Cheng T.G.Cheng J.P.Dai L.Y.Dai X.C.Dai D.Dedovich A.Denig I.Denisenko J.M.Dias D.z.Ding L.Y.Dong W.H.Dong V.Druzhinin D.S.Du Y.J.Du z.G.Du L.M.Duan D.Epifanov Y.L.Fan S.S.Fang z.J.Fang G.Fedotovich C.Q.Feng X.Feng Y.T.Feng J.L.Fu J.Gao Y.N.Gao P.S.Ge C.Q.Geng L.S.Geng A.Gilman L.Gong T.Gong B.Gou W.Gradl J.L.Gu A.Guevara L.C.Gui A.Q.Guo F.K.Guo J.C.Guo J.Guo Y.P.Guo z.H.Guo A.Guskov K.L.Han L.Han M.Han X.Q.Hao J.B.He S.Q.He X.G.He Y.L.He z.B.He z.X.Heng B.L.Hou T.J.Hou Y.R.Hou C.Y.Hu H.M.Hu K.Hu R.J.Hu W.H.Hu X.H.Hu Y.C.Hu J.Hua G.S.Huang J.S.Huang M.Huang Q.Y.Huang W.Q.Huang X.T.Huang X.J.Huang Y.B.Huang Y.S.Huang N.Hüsken V.Ivanov Q.P.Ji J.J.Jia S.Jia z.K.Jia H.B.Jiang J.Jiang S.z.Jiang J.B.Jiao z.Jiao H.J.Jing X.L.Kang X.S.Kang B.C.Ke M.Kenzie A.Khoukaz I.Koop E.Kravchenko A.Kuzmin Y.Lei E.Levichev C.H.Li C.Li D.Y.Li F.Li G.Li G.Li H.B.Li H.Li H.N.Li H.J.Li H.L.Li J.M.Li J.Li L.Li L.Li L.Y.Li N.Li P.R.Li R.H.Li S.Li T.Li W.J.Li X.Li X.H.Li X.Q.Li X.H.Li Y.Li Y.Y.Li z.J.Li H.Liang J.H.Liang Y.T.Liang G.R.Liao L.z.Liao Y.Liao C.X.Lin D.X.Lin X.S.Lin B.J.Liu C.W.Liu D.Liu F.Liu G.M.Liu H.B.Liu J.Liu J.J.Liu J.B.Liu K.Liu K.Y.Liu K.Liu L.Liu Q.Liu S.B.Liu T.Liu X.Liu Y.W.Liu Y.Liu Y.L.Liu z.Q.Liu z.Y.Liu z.W.Liu I.Logashenko Y.Long C.G.Lu J.X.Lu N.Lu Q.F.Lü Y.Lu Y.Lu z.Lu P.Lukin F.J.Luo T.Luo X.F.Luo Y.H.Luo H.J.Lyu X.R.Lyu J.P.Ma P.Ma Y.Ma Y.M.Ma F.Maas S.Malde D.Matvienko z.X.Meng R.Mitchell A.Nefediev Y.Nefedov S.L.Olsen Q.Ouyang P.Pakhlov G.Pakhlova X.Pan Y.Pan E.Passemar Y.P.Pei H.P.Peng L.Peng X.Y.Peng X.J.Peng K.Peters S.Pivovarov E.Pyata B.B.Qi Y.Q.Qi W.B.Qian Y.Qian C.F.Qiao J.J.Qin J.J.Qin L.Q.Qin X.S.Qin T.L.Qiu J.Rademacker C.F.Redmer H.Y.Sang Anhui University Hefei 230039China Beihang University Beijing 100191China Budker Institute of Nuclear Physics Novosibirsk 630090Russia CAS Key Laboratory of Theoretical Physics Institute of Theoretical PhysicsChinese Academy of SciencesBeijing 100190China Cavendish Laboratory University of CambridgeJJ Thomson AveCambridge CB30HEUnited Kingdom Central China Normal University Wuhan 430079China Central South University Changsha 410083China China University of Geosciences Wuhan 430074China China University of Mining and Technology Xuzhou 221116China École Polytechnique Fédérale de Lausanne(EPFL) LausanneSwitzerland Fudan University Shanghai 200433China Goethe University Frankfurt D-60325 Frankfurt am MainGermany Guangxi Normal University Guilin 541004China Guangxi Uninversity Nanning 530004China Hangzhou Institute for Advanced Study UCASHangzhou 310024China Hebei Normal University Shijiazhuang 050024China Hebei University Baoding 071002China Hefei University of Technology Hefei 230601China Helmholtz Institute Mainz Staudinger Weg 18D-55099 MainzGermany Henan Normal University Xinxiang 453007China Henan University Kaifeng 475004China High Energy Physics Center Chung-Ang UniversitySeoul 06974Korea Higher School of Economy 11 Pokrovsky Bulvar Moscow 109028Russia Huangshan University Huangshan 245000China Hubei University of Automotive Technology Shiyan 442002China Hunan Normal University Changsha 410081China Hunan University of Science and Technology Xiangtan 411201China Hunan University Changsha 410082China Indiana University BloomingtonIndiana 47405USA Inner Mongolia University Hohhot 010021China Institute of Advanced Science Facilities Shenzhen 518107China Institute of High Energy Physics Chinese Academy of SciencesBeijing 100049China Institute of Modern Physics Chinese Academy of SciencesLanzhou 730000China Institute of Physics Academia SinicaTaipeiTaiwan 11529China Institute of Theoretical Physics Chinese Academy of SciencesBeijing 100190China Jilin University Changch

The superτ-charm facility(STCF)is an electron–positron collider proposed by the Chinese particle physics community.It is designed to operate in a center-of-mass energy range from 2 to 7 GeV with a peak luminosity of 0.5×10^(35) cm^(–2)·s^(–1) or higher.The STCF will produce a data sample about a factor of 100 larger than that of the presentτ-charm factory—the BEPCII,providing a unique platform for exploring the asymmetry of matter-antimatter(charge-parity violation),in-depth studies of the internal structure of hadrons and the nature of non-perturbative strong interactions,as well as searching for exotic hadrons and physics beyond the Standard Model.The STCF project in China is under development with an extensive R&D program.This document presents the physics opportunities at the STCF,describes conceptual designs of the STCF detector system,and discusses future plans for detector R&D and physics case studies.

关键词： electron–positron collider tau-charm region high luminosity STCF detector conceptual design

SYNTHESIS　AND　CATALYTIC　PROPERTIES　OF　LAYERED　DOUBLE　HYDROXIDES　PILLARED　BY　HETEROPOLYOXOMETALATE

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Chinese Chemical Letters 1995年第8期6卷 719-722页

作者： xu, z He, HM zhou, DM Wen, LS Jiang, D Wu, Y Jilin Univ Dept Chem Changchun 130023 Peoples R China Chinese Acad Sci Changchun Inst Appl Chem Changchun 130021 Peoples R China

ＳＹＮＴＨＥＳＩＳＡＮＤＣＡＴＡＬＹＴＩＣＰＲＯＰＥＲＴＩＥＳＯＦＬＡＹＥＲＥＤＤＯＵＢＬＥＨＹＤＲＯＸＩＤＥＳＰＩＬＬＡＲＥＤＢＹＨＥＴＥＲＯＰＯＬＹＯＸＯＭＥＴＡＬＡＴＥ￥ＺｈｅｎｇＸＵ；ＨｅＭｉｎｇＨＥ；Ｄｏｎ... 详细信息

ＳＹＮＴＨＥＳＩＳＡＮＤＣＡＴＡＬＹＴＩＣＰＲＯＰＥＲＴＩＥＳＯＦＬＡＹＥＲＥＤＤＯＵＢＬＥＨＹＤＲＯＸＩＤＥＳＰＩＬＬＡＲＥＤＢＹＨＥＴＥＲＯＰＯＬＹＯＸＯＭＥＴＡＬＡＴＥ￥ＺｈｅｎｇＸＵ；ＨｅＭｉｎｇＨＥ；ＤｏｎｇＭｅｉＺＨＯＵ；ＬｉｎｇＳｈｅｎ...

关键词： LAYER CATA

US economic and trade sanctions against China: A loss-loss confrontation

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Economic and Political Studies 2023年第1期11卷 17-44页

作者： Liang Guo Sizhu Wang Nicole z.xu Jack H.Brown College of Business and Public Administration California State UniversitySan BernardinoCAUSA School of Finance Renmin University of ChinaBeijingChina Chinese American Youth Association AtlantaGAUSA

The economic and trade sanctions implemented by the United States(US)against China have lasted for a few decades and the structural imbalance of the US–China trade relationship has ultim-ately been escalated to a trade war recently.We examine the eco-nomic impacts of US sanctions against China on both sponsor and target countries during the last 20 years.We find that such impacts have significantly changed over time.On one hand,US economic sanctions have gradually extended from China’s labour-intensive to high value-added products and they have largely slowed down China’s trade growth for the last decade.On the other hand,US consumers and businesses have faced higher pri-ces and production costs for Chinese imports(or import substi-tutes)in the wake of the increasing US trade sanctions,leading to great deadweight losses to the sponsor country.In addition,US economic and trade sanctions against China have largely impacted other economies involved in US–China trade as well.The intermediary status of the Hong Kong SAR has been greatly challenged.Overall,US economic and trade sanctions have caused pain on both China and the US,but their impact on China(the target country)has been largely weakened.

关键词： Economic sanctions US–China trade war export control

Laser additive manufacturing of strong and ductile Al-12Si alloy under static magnetic field

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Journal of Materials Science & Technology 2023年第32期163卷 101-112页

作者： R.Wang J.Wang L.M.Lei S.Yu T.Hu S.S.Shuai S.z.xu z.H.Cao X.P.Li C.Y.Chen z.M.Ren State Key Laboratory of Advanced Special Steels School of Materials Science and EngineeringShanghai UniversityShanghai 200444China AECC Commercial Aircraft Engine Co. Ltd.Shanghai 201108China School of Mechanical and Manufacturing Engineering The University of New South Wales(UNSW Sydney)Sydney NSW 2052Australia

Rapid cooling and solidification during laser additive manufacturing(LAM)can produce ultra-fine microstructure with higher strength.However,the non-uniform cell/grain structure can easily result in early stress concentration and fracture during deformation,which remains a major challenge for the LAM field.Using Al-12Si as the model alloy,we employed the external static magnetic field(SMF)to modulate the laser powder bed fusion process(L-PBF),demonstrating a uniform microstructure with a refined cell structure.The mechanical properties show that the SMF can produce a combination of high tensile strength of 451.4±0.5 MPa and large uniform elongation of 10.4%±0.79%,which are superior to those of previously-reported Al-Si alloys with post-treatment or element alloying.The mechanism analysis based on multi-scale simulation reveals the determining role of SMF in rapid solidification,and this method is applicable to the microstructure control of other metallic materials during LAM.

关键词： Laser powder bed fusion Magnetic field Al alloys Grain refinement Strengthening mechanism

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电介质材料和物理专题编者按

物理学报 2020年第12期69卷 1-1页

作者： Li X.-G. xu z.

电介质材料有许多独特的物理性质,如介电、压电、热释电、铁电、电光、非线性光学及其耦合特性等,在传感、换能、探测、医疗、通信、国防等众多领域具有广泛的应用价值.相关的物理研究主要涉及介电材料内部束缚电荷在电、磁、光、力、... 详细信息

电介质材料有许多独特的物理性质,如介电、压电、热释电、铁电、电光、非线性光学及其耦合特性等,在传感、换能、探测、医疗、通信、国防等众多领域具有广泛的应用价值.相关的物理研究主要涉及介电材料内部束缚电荷在电、磁、光、力、热等外场作用下的极化过程和与极化相关的各种物理现象;通过设计材料的成分与结构等,揭示诸多性能的调控规律和微观机制,在此基础上开发高性能电子器件.

关键词：电介质材料非线性光学物理现象极化过程束缚电荷介电材料外场作用微观机制

HOT DEFORMATION AND MARTENSITIC TRANSFORMATION BEHAVIORS OF Fe-32%Ni ALLOY

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Acta Metallurgica Sinica(English Letters) 2006年第2期19卷 133-138页

作者： J. Huang z. xu Cold Rolling Mill Baoshan Iron ＆ Steel Co. Ltd Shanghai 201900 China Key Laboratory for High Temperature Materials and Tests of Ministry of Education Shanghai Jiaotong University Shanghai 200030 China

The Hot deformation and martensitic transformation behaviors of Fe-32%Ni alloy was investigated by measurements of electrical resistance and X-ray diffraction. With the increase in strain, the austenite goes through from the work-hardened to the partial dynamcally re-crystallized and then to the completed dynamically re-crystallized. The martensitic transformation characteristics depend on the austenite states. The work-hardening in small strain is helpful to martensitic transformation due to the low dislocation density and little lattice distortion, while the high dislocation density and severe lattice distortion by the increase in strain will hinder the martensitic nucleation. Once dynamic re-crystallization （ DRX ） takes place, the martensitic transformation will be enhanced again, which is related to the heterogeneous dynamic substructures. The growing DRX grain can enhance the martensitic nucleation due to the low dislocation density near its grain boundary.

关键词： Fe-32%Ni alloy hot deformation work hardening dynamic re-crystallization martensitic transformation

Riverine sulfate sources and behaviors in arid environment,Northwest China:Constraints from sulfur and oxygen isotopes

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Journal of Environmental Sciences 2024年第3期137卷 716-731页

作者： Yifu xu Wenjing Liu Bing xu zhifang xu Key Laboratory of Cenozoic Geology and Environment Institute of Geology and GeophysicsChinese Academy of SciencesBeijing 100029China Innovation Academy for Earth Science Chinese Academy of SciencesBeijing 100029China University of Chinese Academy of Sciences Beijing 100049China

The fate of riverine sulfate ion (SO_(4)^(2-)) and its environmental effects in arid environment are difficult to evaluate due to its complicated sources and strongly coupled behaviors with water cycle which is significantly modified by humans.To understand the sulfur cycle in aquatic systems in arid environment,the chemical and sulfur and oxygen isotopic compositions (δ^(34)S_(SO4)and δ^(18)O_(SO4)) of major rivers around the Badain Jaran Desert,northwestern China,were investigated.These rivers had averaged SO_(4)^(2-)content at 1336μmol/L,over 10times higher than the global average.The δ^(34)S_(SO4)and δ^(18)O_(SO4)values ranged from-5.3‰to+11.8‰and+1.6‰to+12.8‰,respectively.The end-member analysis and the inverse model showed that riverine sulfate was mainly derived from evaporites dissolution (0-87%),sulfide oxidation (13%-100%) and precipitation (0-33%),indicating heterogeneity in sulfur sources and behaviors along the river drainage with the lithology variations and climate gradients.Multiple isotopic tools combining with hydro-chemistry compositions could be applied to reveal sulfur cycle in arid environment.Based on the calculation,sulfide oxidation plays the primary role in the headwater and upstream in the Qilian-Mountains area,where sulfide is widely exposed.While the proportion of evaporites dissolution contributing to riverine sulfate is much higher in downstream in a drier environment.Besides,less precipitation and higher temperature can lead to more intensive evaporation,affecting the process of sulfide oxidation and enhancing the rates of evaporites dissolution and sulfate precipitation in the basin.

关键词： Sulfur and oxygen isotopes Source apportionment Inverse model Arid environment Inland rivers Northwestern China