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Fluctuation theorem for entropy production at strong coupling

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Chinese Physics B 2020年第1期29卷 175-180页

作者： y y xu J Liu M Feng Faculty of Science Kunming University of Science and TechnologyKunming 650500China Faculty of Mechanical and Electrical Engineering Kunming University of Science and TechnologyKunming 650500China State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics Wuhan Institute of Physics and MathematicsChinese Academy of SciencesWuhan 430071China School of Physics and Microelectronics Zhengzhou UniversityZhengzhou 450001China

Fluctuation theorems have been applied successfully to any system away from thermal equilibrium,which are helpful for understanding the thermodynamic state *** investigate fluctuation theorems for strong coupling between a system and its reservoir,by path-dependent definition of work and heat satisfying the first law of *** present the fluctuation theorems for two kinds of entropy *** is the informational entropy production,which is always non-negative and can be employed in either strong or weak coupling *** other is the thermodynamic entropy production,which differs from the informational entropy production at strong coupling by the effects regarding the *** find that,it is the negative work on the reservoir,rather than the nonequilibrium of the thermal reservoir,which invalidates the thermodynamic entropy production at strong *** results indicate that the effects from the reservoir are essential to understanding thermodynamic processes at strong coupling.

关键词： fluctuation theorem entropy production strong coupling

Studies on monodispersed colloidal particles of doped yttrium compounds

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Chinese Journal of Chemistry 1995年第3期13卷 199-206页

作者： DENG, HM xu, y GU, yD FUDAN UNIV ANAL & MEASUREMENT RES CTRSHANGHAI 200433PEOPLES R CHINA FUDAN UNIV DEPT CHEMSHANGHAI 200433PEOPLES R CHINA

Monodispersed particles of doped yttrium basic carbonates were prepared at aging at elevated temperature corresponding salts solutions in the presence of urea. Coprecipitation in mixed solutions of yttrium, lanthanum and neodymium salts under similar experimental conditions yielded composite particles of basic carbonates. The content of the three metals in the solids followed closely the initial composition of the reacting solutions. On calcination all prepared solids converted to their corresponding oxides while retaining their particle morphology. The so-prepared powders were characterized by various techniques.

关键词： yTTRIUM COMPOUNDS MONODISPERSED PARTICLES UREA DECOMPOSITION

Studies on the energy transfer system of terbium-norfloxacin chelate and its interaction with serum albumins

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Chinese Journal of Chemistry 1997年第2期15卷 138-143页

作者： xu, y Shen, HX Huang, HG NANKAI UNIV DEPT CHEMTIANJIN 300071PEOPLES R CHINA HEBEI INST TECHNOL DEPT CHEM ENGNTANGSHAN 063009HEBEIPEOPLES R CHINA

The energy absorbed by norfloxacin could be transferred to terbium(III) through chelation of norfloxacin with terbium(III), then the characteristic fluorescence emission could be observed. The interaction of serum albumins with norfloxacin have been investigated in this paper. The results showed that HSA could inhibit the energy transfer between norfloxacin and terbium(III). But, BSA could not. It was shown that the binding properties of norfloxacin to HSA and BSA were totally different.

关键词： norfloxacin terbium(III) energy transfer HSA BSA

Filters and structure of lattice implication algebra

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Chinese Science Bulletin 1997年第18期42卷 1517-1520页

作者： Liu, J xu, y Department of Applied Mathematics Southwest Jiaotong University Chengdu China

IN order to research the logical system whose propositional value is given in a lattice from

关键词： lattice implication algebra filter generated filter.

A NOVEL METHOD FOR EVALUATING PLANE STRESS DyNAMIC FRACTURE TOUGHNESS OF 0Cr18Ni10Ti STAINLESS STEEL WELDED JOINTS

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Acta Metallurgica Sinica(English Letters) 2008年第4期21卷 303-312页

作者： Z.J. xu y.L. Li School of Aeronautics Northwestern Polytechnical University Xi＇an 710072 China

A novel method was proposed for the evaluation of Mode I dynamic fracture toughness （DFT） under plane stress and small scale yielding conditions for welded joints of stainless steel （SS）, 0Cr18Ni10Ti. In a hybrid experimental-numerical approach, the experiments were carried out on the Hopkinson pressure bar apparatus, and three dimensional （3D） transient numerical simulations were performed by a finite element （FE） computer program. Macroscopical plastic deformation was observed at the loading and supporting points, on the specimens, after the test, which could cause a large error if omitted in the numerical simulation. Therefore, elustic-viscoplustic analysis was performed on the specimen by adopting the Johnson-Cook （J-C） model to describe the rate-dependent plastic flow behavior of the material. The material heterogeneity in the mismatched welded joints, induced by the difference in the base metal （BM） and the weld metal （WM） in yield stress, has also been taken into consideration by using the J-C models separately. Good accordance was obtained between the experimental and the computational results by the present approach. The relationship between plane stress DFT and loading rate was also obtained on the order of 108 MPa.m^1/2.s^-1.

关键词： 0Cr18Ni10Ti Welded joint High strain rate Dynamic fracture Plane stress

COORELATION ANALySIS OF SURFACE PRESSURE FLUCTUATIONS ON THREE EQUISPACED CyLINDERS

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Journal of Hydrodynamics 2001年第2期13卷 55-62页

作者： Dong, L.y. xu, y.H. Huang, D.Q. Inst. of Appl. Math. and Mech. Shanghai Univ. Shanghai 200072 China

The fluctuating pressures on the surface of three circular cylinders in equispaced arrangement were measured simultaneously in the medium subcritical regime (Re=3×104). The distributions of their rms values and circumferential correlation were obtained in the spacing range from 1.25 to 6.0. The spatial correlation of pressures of two pressure taps on two different cylinders at the same azimuth was investigated as well. Owing to different flow patterns in various arrangements and spacing, these correlation curves of pressure show different distributions. The lift fluctuation can be estimated qualitatively from the circumferential coefficient curve with the knowledge of the rms pressure distribution. Some critical spacing for each arrangement were found that the flow regimes and the corresponding pressure correlation take a sudden change. Flow interference between cylinders in each arrangement was also discussed with various flow regimes.

关键词： Cylinders (shapes) Experiments Flow interactions Flow patterns Pressure distribution Pressure measurement

Photoluminescence of ZnS Clusters in Zeolite-y

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Journal of Materials Science & Technology 1997年第5期13卷 397-404页

作者： Chen, W Wang, ZG Lin, ZJ xu, y Lin, Ly Lab. of Semiconductor Materials Sciences Institute of Semiconductors Chinese Academy of Sciences Beijing 100083 China

Two obvious emissions are observed from the ZnS clusters encapsulated in zeolite-y. The emission around 355 nm is sharp and weak, locating at the onset of the absorption edge. The band around 535 nm is broad, strong and Stokes-shifted. Both the two emissions shift to blue and their intensities firstly increase then decrease as the loading of ZnS in zeolite-y or clusters size decreases. Through investigation, the former is attributed to the excitonic fluorescence, and the latter to the trapped luminescence from surface states. The cluster size-dependence of the luminescence may be explained qualitatively by considering both the carrier recombination and the nonradiative recombination rates. Four peaks appearing in the excitation spectra are assigned to the transitions of 1S-1S, 1S-1P, 1S-1D and surface state, respectively. The excitation spectra of the clusters do not coincide with their absorption spectra. The states splitted by quantum-size confinement are detected in the excitation spectra, but could not be differentiated in the optical absorption spectra due to inhomogeneous broadening. The size-dependence of the excitation spectra is similar to that of the absorption spectra. Both the excitation spectra of excitonic and of trapped emissions are similar, but change in relative intensity and shift in position are observed.

关键词： Zeolites

Syntax of first-order lattice valued logic system FM

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Chinese Science Bulletin 1997年第16期42卷 1337-1340页

作者： xu, y Qin, Ky Song, ZM Sw Jiaotong Univ Dept Appl Math Chengdu 610031 Peoples R China

PAVELKA in ref. [1] established a propositional logic system whose truth values domain is an enriched residuated lattice and obtained some beautiful results. In order to study more general lattice valued logic systems, we proposed the concept of lattice implication algebra, discussed the corresponding lattice valued propositional logic system, and established a

关键词： lattice implication algebra lattice valued logic formal proof.

LOW CyCLE FATIGUE BEHAVIOR OF AZ91HP ALLOy IN AS HIGHP RESSURE DIE CASTING

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Acta Metallurgica Sinica(English Letters) 2000年第4期13卷 961-966页

作者： Liu, Z. xu, y.y. Wang, Z.G. Wang, y. Liu, Z.y. Inst of Metal Research Chinese Acad of Sciences Shenyang China

Fully reversed total strain-controlled low-cycle fatigue tests were conducted at room temperature in air to study the fatigue behavior of AZ91HP magnesium alloy in as high pressure die casting and subsequently heat treatment. All the specimens in different heat histories exhibit cyclic strain hardening in different degrees. It is difficult to distinguish the fatigue behavior of the die casting specimens from that of the solution aging specimens. The solution treated specimens show longer fatigue life at high strain amplitude and shorter fatigue life at low strain amplitude than the die casting and solution aging specimens though they have the lowest yield strength with higher strain hardening. Fatigue fracture surfaces for strain amplitude larger than 0.005 show very similar to those found by monotonic tensile tests. The SEM examination reveals that the regions of fatigue crack growth and final fracture can be characterized by quasi-cleavage mechanisms, but some shallow dimples, slip bands and secondary cracks are found on the fracture surface in the fracture crack growth areas.

关键词： Cracks Die casting Fatigue of materials Heat treatment