检索结果-南通市图书馆

An Adaptive Substructure-Based Model Order Reduction Method for Nonlinear Seismic Analysis in OpenSees

在线全文

学校读者我要写书评

暂无评论

Computer Modeling in Engineering & Sciences 2020年第7期124卷 79-106页

作者： Jian Wang ming fang Hui Li Key Lab of Structures Dynamic Behavior and Control of the Ministry of Education Harbin Institute of TechnologyHarbin150090China Key Lab of Smart Prevention and Mitigation of Civil Engineering Disasters of the Ministry of Industry and Information Technology Harbin Institute of TechnologyHarbin150090China College of Shipbuilding Engineering Harbin Engineering UniversityHarbin150001China.

Structural components may enter an initial-elastic state,a plastic-hardening state and a residual-elastic state during strong seismic *** the residual-elastic state,structural components keep in an unloading/reloading stage that is dominated by a tangent stiffness,thus structural components remain residual deformations but behave in an elastic *** has a great potential to make model order reduction for such structural components using the tangent-stiffness-based vibration modes as a reduced order *** this paper,an adaptive substructure-based model order reduction method is developed to perform nonlinear seismic analysis for structures that have a priori unknown damage *** method is able to generate time-varying substructures and make nonlinear model order reduction for substructures in the residual-elastic *** finite element program OpenSees has been extended to provide the adaptive substructure-based nonlinear seismic *** the low level of OpenSees framework,a new abstract layer is created to represent the time-varying substructures and implement the modeling process of *** the high level of OpenSees framework,a new transient analysis class is created to implement the solving process of substructure-based governing *** with the conventional time step integration method,the adaptive substructure-based model order reduction method can yield comparative results with a higher computational efficiency.

关键词： Adaptive substructure modeling model order reduction nonlinear seismic

Synthesis, structure, and magnetic properties of two novel lanthanide-organic frameworks

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Science China Chemistry 2009年第9期52卷 1456-1462页

作者： LI XiuHua fang ming ZHAO Bin Department of Chemistry Nankai UniversityTianjin 300071China Department of Chemistry Chifeng CollegeInner Mongolia 024000China

Two novel metal-organic frameworks, {[Eu(phen)(NDA)1.5(H2O)]}n ((1); NDA = 2,6-naphthalenedicarboxylate ions, phen = 1,10-phenanthroline) and {[Gd(phen)(NDA)1.5]·0.5H2NDA}n (2), have been synthesized under hydrothermal conditions. The structure analyses of 1 and 2 reveal that the two compounds belong to the triclinic system with space group P-1. Compound 1 features a 2D lattice structure while compound 2 displays a novel 3D architecture. The two frameworks were further characterized by elemental analyses, luminescent spectrua, and variable-temperature magnetic susceptibilities. The investigation of lumi-nescent property reveals that 1 exhibits characteristic red emission of Eu3+. Magnetic investigation suggests that the ferromagnetic coupling exists between adjacent Gd3+ in compound 2.

关键词： 2 6-naphthalenedicarboxylate lanthanide complexes ferromagnetic coupling luminescent property

Coexistence of Ferromagnetism and Superconductivity in EuSr_(2)Ru_(1-x)Nb_(x)Cu_(2)O_(8)

在线全文

学校读者我要写书评

暂无评论

Chinese Physics Letters 2001年第7期18卷 963-966页

作者： fang ming-Bao fang ming-Hu XU Zheng JIAO Zheng-Kuan Department of Materials Science and Technology Tongji UniversityShanghai 200092 Department of Physics Zhejiang UniversityHangzhou 310027

The structural,magnetic and transport properties of EuSr_(2)Ru_(1-x)Nb_(x)Cu_(2)O_(8)(x=0,0.1,0.2 and 0.5)samples have been investigated by means of x-ray diffraction,magnetization and resistance *** is found that the EuSr_(2)Ru_(1-x)Nb_(x)Cu_(2)O_(8) compound exhibits a ferromagnetic order of the Ru moments below the Curie temperature 130.19 K,and becomes superconducting at a much lower critical temperature of 10 *** experimental observation that partial substitution of Nb for Ru in this system results in the decrease of the Curie temperature further supports the idea that the ferromagnetic order involves only Ru moments in this *** suggest that the decrease of the superconducting critical temperature Tc due to the partial substitution of Nb for Ru originates from the decrease of the carrier concentration in the CuO_(2) plane because of Nb existing always in the Nb5+valance state while Ru is in a mixted valance state between Ru4+and Ru5+.The coexistence of ferromagnetism and superconductivity is also discussed.

关键词： resistance ferromagnetic (x)

Mechanism analysis of non-sinusoidal oscillation of continuous casting mold synchronously driven by double servomotors

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Iron and Steel Research International 2017年第3期24卷 251-257页

作者： Chao Zhou Xing-zhong Zhang fang Wang Ping-fei Liu Yi-ming fang National Engineering Research Center for Equipment and Technology of Cold Strip Rolling Yanshan University Qinhuangdao 066004 Hebei China Hebei Agricultural University Qinhuangdao 066003 Hebei China School of Science Yanshan University Qinhuangdao 066004 Hebei China

Due to the disadvantages of complexity,high maintenance and vast investment of the electro-hydraulic servo oscillator,a new mechanical device synchronously driven by double servomotors was proposed. The working principle of the non-sinusoidal oscillator was analyzed and the model of the oscillator was validated via simulation ***,taking advantage of resonance technology,the hinging force and moment were calculated. The results showed that the hinging force and driving moment reduced,which was useful in reducing the impact of the hinge and prolonging the service life of the bearing. Besides,the best initial spring pressure was 0. 9 times the mold gravity,which improved the oscillation system stability and reduced the load fluctuation and servomotor driving power.

关键词： Continuous casting Mold Non-sinusoidal oscillation Resonance technology Oscillation mechanism

Quantum Phase Transitions in Spin Star Configuration

在线全文

学校读者我要写书评

暂无评论

Communications in Theoretical Physics 2008年第5期49卷 1353-1356页

作者： DENG Hong-Liang fang Xi-ming Key Laboratory of Quantum Structure and Quantum Control of Ministry of Education and Department of Physics Hunan Normal University Changsha 410081 China

We consider a generalized spin star configuration that can be solved exactly, with the central spin-1/2 system embedded in an outer ring of N spin-1/2 particles （denoted as spin bath）. In this model, we consider a modified version of the spin star model, by taking into account, besides the interaction of the central spin with the bath, the interactions between the spins of the bath as well. The general expressions of the eigenstates as well as the eigenvalues of the model are derived with the use of the symmetries of system. We then investigate the properties of the ground quantum phase transitions in some limiting cases in the model and show that the occurrence of quantum phase transitions and the desired ground states can be obtained by varying the external control parameters.

关键词： quantum phase transitions ground state

Small-Scale Brightenings in the UV Continuum of an M9.1 Solar Flare

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Astronomy and Astrophysics 2007年第5期7卷 721-732页

作者： Lin Wang Cheng fang ming-De Ding Department of Astronomy Nanjing University Nanjing 210093

We analyze an M9.1 two-ribbon solar flare which occurred on 2004 July 22 using the TRACE white-light and 1700 A images, the RHESSI, and the SOHO/MDI data. We find many small-scale fast-varying brightenings that appeared in the white-light and 1700 A images along the flare ribbons. Some of them underwent rapid motions in weak magnetic field regions. We identify these short-lived brightenings as UV continuum enhancement. Our preliminary result shows that the brightenings are closely related to the HXR emission. They have a lifetime of 30-60 s and a typical size of about 1＂-2＂. The intensity enhancement is about 150-200 times the mean value of the quiet-Sun. According to previous works, we infer that the 1700A enhancement may be dominated by the increased emission of 1680A continuum coming from the temperature minimum region. The impulsive feature in the 1700 A light curves of the small-scale brightenings may be due to the irradiation of the impulsive CIv line intensity caused by the bombardment of non-thermal electron beams.

关键词： Sun activity -- Sun flares -- Sun UV radiation

Microstructure and tribological behavior of tungsten inert gas welding arc brazing tin-based babbit

在线全文

学校读者我要写书评

暂无评论

Rare Metals 2020年第2期39卷 193-199页

作者： fang-ming Zhou Qing-Ya Zhang ming-Xiao Shi Hui Li Jun-Wu Guo Jiangsu Province Key Laboratory of Advanced Welding Technology Jiangsu University of Science and TechnologyZhenjiang212003China

The microstructure of the tin-based babbit obtained by the method of tungsten inert gas welding(TIG)arc brazing was studied by optical microscopy(OM)and X-ray diffraction(XRD).Tribological behavior was investigated by high-temperature friction and wear testing machine(HTFWT),laser scanning confocal microscopy(LSCM),scanning electron microscopy(SEM)and energydispersive spectrometer(EDS).It can be found that the higher welding current of the melting tin-based babbit makes it possible to form isomer structure with fine crystals of the cubic SnSb compounds and large star Cu6Sn5 compounds so that a higher hardness can be achieved,and a lower wear rate can be obtained over the entire distance of sliding *** the applied load is 2 N,the contact surface is oxidized due to the accumulation of friction heat and oxide,which plays a role of lubricated ***,the softer Sn-based solid solution forms obvious furrow under abrasive wear,and the harder SbSn and Cu6Sn5 intermetallic compounds shatter and leave a hole under friction.

关键词： Tin-based babbit TIG arc brazing Microstructure Tribological behavior

A remote sensing system of vehicle emissions based on tunable diode laser technology

在线全文

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2006年第1期18卷 154-157页

作者： ZENG Jun GUO Hua-fang HU Yue-ming College of Automation Science and Engineering South China University of Technology Guangzhou 510640 China

As being an effective real-time method of monitoring vehicle emissions on-road, a remote sensing system based on the tunable diode laser （TDL） technology was presented, and the key technologies were discussed. A field test in Guangzhou（Guangdong, China） was performed and was found that the factors, such as slope, instantaneous speed and acceleration, had significant influence on the detectable rate of the system. Based on the results, the proposal choice of testing site was presented.

关键词： remote sensing tunable diode laser vehicle emission detectable rate

Recent Progress on Metal-Enhanced Photocatalysis:A Review on the Mechanism

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Research 2021年第1期2021卷 885-900页

作者： ming fang Xiaoli Tan Zhixin Liu Baowei Hu Xiangke Wang College of Environmental Science and Engineering North China Electric Power UniversityBeijing 102206China School of Life Science Shaoxing UniversityShaoxing 312000China

Metal-enhanced photocatalysis has recently received increasing interest,mainly due to the ability of metal to directly or indirectly degrade *** this review,we briefly review the recent breakthroughs in metal-enhanced *** discussed the recent progress of surface plasmon resonance(SPR)effect and small size effect of metal nanoparticles on photocatalysis;in particular,we focus on elucidating the mechanism of energy transfer and hot electron injection/transfer effect of metal nanoparticles and clusters while as photocatalysts or as ***,we discuss the potential applications of metal-enhanced photocatalysis,and we also offer some perspectives for further investigations.

关键词： breakthrough effect dating