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Damping capacity of Fe_(83)Ga_(17) magnetostrictive alloy under magnetic field

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Rare Metals 2024年第1期43卷 402-409页

作者： Shao-Wen Yan xing Mu Bing-Jie Liu Li-hong Xu shi-Hai Guo Yan Qi hong-Ping Zhang Department of Functional Material Research Central Iron and Steel Research InstituteBeijing 100081China

The damping performance of Fe_(83)Ga_(17) alloys has been investigated in the static magnetic field (H). The results demonstrate that the damping peak value can be adjusted between 0.020 and 0.085 under the magnetic f... 详细信息

关键词： alloy magnetic alloys

Resilient performance of self-centering hybrid rocking walls with curved interface under pseudo-static loading

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Earthquake Engineering and Engineering Vibration 2024年第1期23卷 65-85页

作者： Su xing Yan shi Sun Xianglei Wang Tao School of Civil Engineering Shenyang Jianzhu UniversityShenyang 110168China PetroChina East China Design Institute Co. Ltd.Qingdao 266000China Qingdao Country Garden Bolin Real Estate Co. Ltd.Qingdao 266100China

Frame and rocking wall(FRW)structures have excellent resilient performance during ***,the concrete at interfacial corners of rocking walls(RWs)is easily crushed due to local extreme compression during the rocking *** innovative RW with a curved interface is proposed to prevent interfacial corners from producing local damage,enhancing its earthquake resilient performance(ERP).The precast wall panel with a curved interface is assembled into an integral self-centering hybrid rocking wall(SCRW)by two post-tensioned unbonded prestressed ***,two ordinary energy dissipation steel rebars and two shear reinforcements are arranged to increase the energy dissipation capacity and lateral *** SCRW specimens and one monolithic reinforced concrete(RC)shear wall(SW)were tested under pseudo-static loading to compare the ERPs of the proposed SCRW and the SW,focusing on studying the effect of the curved interface on the *** key resilient performance of rocking effects,failure modes,and hysteretic properties of the SCRW were *** results show that nonlinear deformations of the SCRW are concentrated along the interface between the SCRW and the foundation,avoiding damage within the *** restoring force provided by the prestressed tendons can effectively realize self-centering capacity with small residual deformation,and the resilient performance of the SCRW is better than that of monolithic *** addition,the curved interface of the SCRW makes the rocking center change and move inward,partially relieving the stress concentration and crush of *** rocking range of the rocking center is about 41.4%of the width of the SCRW.

关键词： self-centering hybrid rocking wall(SCRW) monolithic shear wall(SW) earthquake resilient performance(ERP) curved interface rocking center

Numerical and Experimental Analysis of the Aerodynamic Torque for Axle-Mounted Train Brake Discs

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Fluid Dynamics & Materials Processing 2024年第8期20卷 1867-1882页

作者： Nan Liu Chen hong Xinchao Su xing Jin Chen Jiang Yuqi shi Bingkun Wang Brake System Laboratory CRCC(Qingdao)Vehicle Inspection Station Co.Ltd.Qingdao266031China Brake System Laboratory CRRC Qingdao Sifang Rolling Stock Research Institute Co.Ltd.Qingdao266031China The State Key Laboratory of Heavy-Duty and Express High-Power Electric Locomotive Central South UniversityChangsha410075China Key Laboratory of Traffic Safety on Track of Ministry of Education School of Traffic&Transportation EngineeringCentral South UniversityChangsha410075China National&Local Joint Engineering Research Center of Safety Technology for Rail Vehicle Changsha410075China

As the velocity of a train increases,the corresponding air pumping power consumption of the brake discs increases *** the present experimental study,a standard axle-mounted brake disc with circumferential pillars was analyzed using a 1:1 scale model and a test rig in a wind *** particular,three upstream velocities were selected on the basis of earlier investigations of trains operating at 160,250,and 400 km/h,***,3D steady computational fluid dynamics(CFD)simulations of the flow field were conducted to compare with the wind tunnel test *** results for a 3-car train at 180 km/h demonstrated:(1)good agreement between the air resistance torques obtained from the wind tunnel tests and the related numerical results,with differences ranging from 0.95%to 5.88%;(2)discrepancies ranging from 3.2 to 3.8 N·m;(3)cooling ribs contributing more than 60%of the air resistance torque;(4)the fast rotation of brake discs causing a significantly different flow field near the bogie area,resulting in 25 times more air pumping power loss than that obtained in the stationary brake-disc case.

关键词： Axle-mounted train brake disc aerodynamic torque wind tunnel test numerical simulation

Microstructure and magnetocaloric properties of melt-extracted SmGdDyCoAl high-entropy amorphous microwires

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Rare Metals 2024年第3期43卷 1234-1242页

作者： shi-Jie Wei hong-Xian Shen Lun-Yong Zhang Lin Luo Xin-xing Tang Jian-Fei Sun Xiao-Qing Li School of Materials Science and Engineering Harbin Institute of TechnologyHarbin150001China Applied Materials Physics Department of Materials Science and EngineeringKTH-Royal Institute of Technology10044StockholmSweden

This paper presents a systematic investigation of the microstructure and magnetocaloric properties of melt-extracted Sm_(20)Gd_(20)Dy_(20)Co_(20)Al_(20)high-entropy *** fabricated wires exhibited an amorphous structure,and the temperature interval of the undercooled liquid AT was 45 *** microwires underwent a second-order magnetic transition from a ferromagnetic to a paramagnetic state near the Curie temperature(T_(C)=52 K),The maximum magnetic entropy change(-ΔS_M^(max)),the relative cooling power and the refrigeration capacity reached 6.34 J·kg^(-1)·K^(-1).422.09 J·kg^(-1)and 332.94 J·kg^(-1),respectively,under a magnetic field change of 5 *** addition,the temperature-averaged entropy changes with two temperature lifts(3 and 10 K)were 6.32 and 6.27 J·kg^(-1)·K^(-1),*** good magnetocalorie performance highlights the significant potential for the Sm_(20)Gd_(20)Dy_(20)Co_(20)Al_(20)microwires to be used as magnetic refrigerant materials in low-temperature region *** work will serve as a valuable reference for future investigations on low-temperature high-entropy magnetocaloric materials.

关键词： Melt-extraction High-entropy amorphous microwires Magnetocaloric effect Magnetic refrigeration

Hierarchical Mixture Models for Zero-inflated Correlated Count Data

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Acta Mathematicae Applicatae Sinica 2016年第2期32卷 373-384页

作者： Xue-dong CHEN hong-xing shi Xue-ren WANG School of Science Huzhou UniversityHuzhou 313000China School of Primary Education Chuxiong Normal UniversityChuxiong 675000China Department of Statistics Yunnan UniversityKunming 650091China

Count data with excess zeros are often encountered in many medical, biomedical and public health applications. In this paper, an extension of zero-inflated Poisson mixed regression models is presented for dealing with multilevel data set, referred as hierarchical mixture zero-inflated Poisson mixed regression models. A stochastic EM algorithm is developed for obtaining the ML estimates of interested parameters and a model comparison is also considered for comparing models with different latent classes through BIC criterion. An application to the analysis of count data from a Shanghai Adolescence Fitness Survey and a simulation study illustrate the usefulness and effectiveness of our methodologies.

关键词： zero-inflation random effect latent class stochastic EM algorithm model selection

Nonlinear Characteristic Analysis of Gas-Interconnected Quasi-Zero Stiffness Pneumatic Suspension System:A Theoretical and Experimental Study

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Chinese Journal of Mechanical Engineering 2024年第3期37卷 338-352页

作者： Xinwei Jiang xing Xu Tianling shi Vincent Akolbire Atindana Automotive Engineering Research Institute Jiangsu UniversityZhenjiang 212013China

Because of significantly changed load and complex and variable driving road conditions of commercial vehicles,pneumatic suspension with lower natural frequencies is widely used in commercial vehicle suspension *** ever,traditional pneumatic suspension system is hardly to respond the greatly changed load of commercial vehicles To address this issue,a new Gas-Interconnected Quasi-Zero Stiffness Pneumatic Suspension(GIQZSPS)is presented in this paper to improve the vibration isolation performance of commercial vehicle suspension systems under frequent load *** new structure adds negative stiffness air chambers on traditional pneumatic suspension to reduce the natural frequency of the *** can adapt to different loads and road conditions by adjusting the solenoid valves between the negative stiffness air ***,a nonlinear mechanical model including the dimensionless stiffness characteristic and interconnected pipeline model is derived for GIQZSPS *** the nonlinear mechanical model of GIQZSPS system,the force transmissibility rate is chosen as the evaluation index to analyze ***,a testing bench simulating 1/4 GIQZSPS system is designed,and the testing analysis of the model validation and isolating performance is carried *** results show that compared to traditional pneumatic suspension,the GIQZSPS designed in the article has a lower natural *** the system can achieve better vibration isolation performance under different load states by switching the solenoid valves between air chambers.

关键词： Pneumatic suspension Quasi-zero stiffness system Gas-interconnected system Nonlinear dynamic modeling

Stability of the Phase Separation State for Compressible Navier-Stokes/Allen-Cahn System

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Acta Mathematicae Applicatae Sinica 2024年第1期40卷 45-74页

作者： Ya-zhou Chen Hakho hong Xiao-ding shi Department of Mathematics College of Mathematics and PhysicsBeijing University of Chemical TechnologyBeijing100029China Institute of Mathematics State Academy of SciencesPyongyangKorea

This paper is concerned with the large time behavior of the Cauchy problem for Navier-Stokes/AllenCahn system describing the interface motion of immiscible two-phase flow in 3-D. The existence and uniqueness of global solutions and the stability of the phase separation state are proved under the small initial perturbations. Moreover, the optimal time decay rates are obtained for higher-order spatial derivatives of density,velocity and phase. Our results imply that if the immiscible two-phase flow is initially located near the phase separation state, then under small perturbation conditions, the solution exists globally and decays algebraically to the complete separation state of the two-phase flow, that is, there will be no interface fracture, vacuum, shock wave, mass concentration at any time, and the interface thickness tends to zero as the time t → +∞.

关键词： Navier-Stokes/Allen-Cahn system existence uniqueness large time behavior decay rate

Quantitative effect of kerogen type on the hydrocarbon generation potential of Paleogene lacustrine source rocks,Liaohe Western Depression,China

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Petroleum Science 2024年第1期21卷 14-30页

作者： Sha-Sha Hui Xiong-Qi Pang Fu-Jie Jiang Chen-Xi Wang Shu-xing Mei Tao Hu hong Pang Min Li Xiao-Long Zhou Kan-Yuan shi State Key Laboratory of Petroleum Resources and Prospecting China University of Petroleum(Beijing)Beijing102249China College of Geosciences China University of Petroleum(Beijing)Beijing102249China Exploration and Development Research Institute PetroChina Liaohe Oilfield CompanyPanjin 124010LiaoningChina

Kerogen types exert a decisive effect on the onset and capacity of hydrocarbon generation of source *** source rocks in the Liaohe Western Depression are characterized by thick deposition,high total organic carbon(TOC)content,various kerogen types,and a wide range of thermal ***,their hydrocarbon generation potential and resource estimation can be *** this study,geochemical tests,numerical analysis,hydrocarbon generation kinetics,and basin modeling were integrated to investigate the differential effects of kerogen types on the hydrocarbon generation potential of lacustrine source *** hydrocarbon generation and expulsion(HGE)models of different kerogen types were established quantitatively upon abundant Rock-Eval/TOC/vitrinite reflectance(R_(o))*** sets of good-excellent source rocks deposited in the fourth(Es4),third(Es3),and first(Es1)members of Paleogene Shahejie Formation,are predominantly types I-II_(1),II_(1)-II_(2),and II-III,*** activation energy of types I-II_(2)kerogen is concentrated(180-230 kcal/mol),whereas that of type III kerogen is widely distributed(150-280 kcal/mol).The original hydrocarbon generation potentials of types I,II_(1),II_(2),and III kerogens are 790,510,270,and 85 mg/g TOC,*** Ro values of the hydrocarbon generation threshold for type I-III source rocks gradually increase from 0.42%to 0.74%,and Ro values of the hydrocarbon expulsion threshold increase from 0.49%to 0.87%.Types I and II_(1)source rocks are characterized by earlier hydrocarbon generation,more rapid hydrocarbon expulsion,and narrower hydrocarbon generation windows than types II_(2)and III source *** kerogen types also affect the HGE history and resource *** types(conventional,tight,and shale oil/gas)and three levels(realistic,expected,and prospective)of hydrocarbon resources of different members in the Liaohe Western Depression are *** suggest that t

关键词： Kerogen type Hydrocarbon generation potential Lacustrine source rocks Liaohe western depression

Ordered Bicontinuous Network Structures Regulated by Orientational Interactions in a Rod-Coil Block Copolymer

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Chinese Journal of Polymer Science 2024年第5期42卷 636-642,I0008页

作者： Xiao-Lin Lyu shi-Chu Yang An-Qi Xiao Ping-Ping Hou Wei Zhang hong-Bing Pan Zhi-Hao Shen xing-He Fan Qi-Feng Zhou Beijing National Laboratory for Molecular Sciences Key Laboratory of Polymer Chemistry and Physics of Ministry of EducationCollege of Chemistry and Molecular EngineeringPeking UniversityBeijing100871China Key Laboratory of Advanced Materials Technologies International(HongKong Macao and Taiwan)Joint Laboratory on Advanced Materials TechnologiesCollege of Materials Science and EngineeringFuzhou UniversityFuzhou350108China

The rich phase behavior of block copolymers(BCPs)has drawn great attention in recent ***,the double diamond(DD)phase is rarely obtained because of the competition between the minimization of interfacial energy and packing ***,a rod-coil BCP containing mesogen-jacketed liquid crystalline polymer is designed to acquire ordered bicontinuous network *** reduction of internal energy originating from the orientational interaction among the rod blocks can compensate for the free energy penalty of packing frustration to stabilize the DD *** resulting BCP can also experience lamellae-to-DD and double gyroid-to-lamellae transitions by changing the annealing *** results make the rod-coil BCP an excellent candidate for the self-assembly of ordered network structures,demonstrating great potential in nanopatterning and metamaterials.

关键词： Block copolymer Rod-coil Ordered bicontinuous phase Double diamond Double gyroid