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PREPARATION OF MESOPOROUS CARBON BY CARBON DIOXIDE ACTIVATION wITH CATALYST

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Acta Metallurgica Sinica(English Letters) 2002年第1期15卷 67-72页

作者： w.z. Shen A.H. Lu J.T. zheng Institute of Coal Chemistry The Chinese Academy of Sciences Taiyuan 030001 China

A mesoporous activated carbon (AC) can be successfully prepared by catalytic activation with carbon dioxide. For iron oxide as catalyst, there were two regions of mesopore size distribution, i.e. 2-5nm and 30-70nm. when copper oxide or magnesium oxide coexisted with iron oxide as composite catalyst, the content of pores with sizes of 2-5nm was decreased, while the pores with 30-70nm were increased significantly. For comparison, AC reactivated by carbon dioxide directly was also investigated. It was shown that the size of mesopores of the resulting AC concentrated in 2-5nm with less volume. The adsorption of Congo red was tested to evaluate the property of the result-ing AC. Furthermore, the factors affecting pore size distribution and the possibility of mesopore formation were discussed.

关键词： activated carbon mesopore. catalytic activation

BEHAVIOR OF FLOw STRESS OF ALUMINUM SHEETS USED FOR PRESSURE CAN DURING COMPRESSION AT ELEVATED TEMPERATURE

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Acta Metallurgica Sinica(English Letters) 2005年第6期18卷 756-762页

作者： G.S. Fu w.z. Chen K. w. Qian School of Mechanical Engineering Fuzhou University Fuzhou 350002 China

The behavior of flow stress of Al sheets used for pressure can prepared by different melt-treatment during plastic deformation at elevated temperature was studied by isothermal compression test using Gleeble1500 dynamic hot-simulation testing machine. The results show that the AI sheets possess the remarkable characteristic of steady state flow stress when they are deformed in the temperature range of 350-500℃ at strain rates within the range of 0.01-10.0s^-1. A hyperbolic sine relationship is found to correlate well the flow stress with the strain rate, and an Arrhenius relationship with the temperature, which implies that the process of plastic deformation at elevated temperature for this material is thermally activated. Compared with the AI pieces prepared by no or conventional melt-treatment, hot deformation activation energy of AI sheets prepared by high-efficient melt-treatment is the smallest （ Q= 168.0kJ/mol）, which reveals that the hot working formability of this material is very better, and has directly to do with the effective improvement of its metallurgical quality.

关键词： Al sheets used for can melt-treatment plastic deformation at elevatedtemperature flow stress hot deformation activation energy

A NOVEL APPROACH FOR THE PREDICTION OF SURFACE PROFILE OF OUTGOING wORKPIECE AND THE CALCULATION OF MEAN ROLL RADIUS IN ALLOY BAR ROLLING

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Acta Metallurgica Sinica(English Letters) 2007年第1期20卷 49-58页

作者： Y.G. Dong w.z. zhang J.F. Song College of Mechanical Engineering Yanshan University Qinhuangdao 066004 Ghina College of Electromechanical Engineering Harbin Institute of Technology Harbin 150001China

In alloy bar rolling process, the component of alloyed steel influenced the spread coefficient greatly, therefore, the component influence coefficient m of different alloyed steel has been determined firstly to calculate the maximum spread. Then the curvature radius of stress free surface and the ＂critical point on the contact boundary＂ have been solved, the surface profile of outgoing workpiece has been obtained. Furthermore, the formula of the equivalent contact section area has been proposed and the mean roll radius has been calculated. The bar rolling experiment and the rigid-plastic FEM （finite element method） simulation have been carried out to verify the novel approach. Compared with experimental data and simulation results, the novel approach can be used in setting processing parameter and design of finishing groove.

关键词： alloyed steel surface profile mean roll radius critical point rigid-plastic FEM (finite element method)

Targeting epigenetic mechanisms in amyloid-β-mediated Alzheimer’s pathophysiology:unveiling therapeutic potential

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Neural Regeneration Research 2025年第1期20卷 54-66页

作者： Jennie z.Li Nagendran Ramalingam Shaomin Li Ann Romney Center for Neurologic Diseases Brigham and Women’s Hospital and Harvard Medical SchoolBostonMAUSA

Alzheimer’s disease is a prominent chronic neurodegenerative condition characterized by a gradual decline in memory leading to *** evidence suggests that Alzheimer’s disease is associated with accumulating various amyloid-βoligomers in the brain,influenced by complex genetic and environmental *** memory and cognitive deficits observed during the prodromal and mild cognitive impairment phases of Alzheimer’s disease are believed to primarily result from synaptic *** life,environmental factors can lead to enduring changes in gene expression and the emergence of brain *** changes,known as epigenetic modifications,also play a crucial role in regulating the formation of synapses and their adaptability in response to neuronal *** this context,we highlight recent advances in understanding the roles played by key components of the epigenetic machinery,specifically DNA methylation,histone modification,and microRNAs,in the development of Alzheimer’s disease,synaptic function,and activity-dependent synaptic ***,we explore various strategies,including enriched environments,exposure to non-invasive brain stimulation,and the use of pharmacological agents,aimed at improving synaptic function and enhancing long-term potentiation,a process integral to epigenetic ***,we deliberate on the development of effective epigenetic agents and safe therapeutic approaches for managing Alzheimer’s *** suggest that addressing Alzheimer’s disease may require distinct tailored epigenetic drugs targeting different disease stages or pathways rather than relying on a single drug.

关键词： Alzheimer’s disease DNA methylation enriched environments histone modification microRNAs non-invasive brain stimulation synaptic plasticity

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AESTHETIC GENESIS

The world of Chinese 2014年第6期 60-61页

作者： w.z.

How did you create the project'Family Album'?'Family Album'was my final major project in London,a project consisting of a series of videos in which I re-enacted my family members and lip-synched to their recorded *** their old photographs,I dressed up as my parents and my grandparents in similar clothes and *** videos are more like

关键词： AESTHETIC GENESIS

BRIGHT LONG AFTERGLOw PHOSPHORESCENCE GLASS MADE OF SrAl_(2)O_(4): Eu^(2+), Dy^(3+) AND GLASS FRITS

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Acta Metallurgica Sinica(English Letters) 2005年第6期18卷 736-740页

作者： X. Y. zhang z. F. Cao L.P. Lu z.H. Bai w.z. wang X. C. wang Department of Materials Science and Engineering Changchun University of Science and Technology Changchun 130022 China

Bright long afterglow phosphorescence glasses were prepared by using SrAl2O4： Eu^2＋, Dy^3＋ phosphors and suitable glass frits together. The SrAl2O4： Eu^2＋, Dy^3＋ phosphors were initially prepared by the solid reaction method. Three kinds of glass frits were prepared to match the SrAl2O4： Eu^2＋, Dy^3＋ phosphors. Effects of the compositions of the glass frits, the ratios of the phosphors to the frits us well us the firing temperature and firing times on the properties of the samples were discussed. XRD analysis indicated the samples exhibited the typical diffraction peaks of SrAlwO4： Eu^2＋, Dy^3＋. The emission spectra of the samples showed broad bands peaking at *** excitation spectra of the samples showed broad bands ranging from 300 to 480hm. These are believed due to the 5d4f-4f transitions of Eu^2＋ in the SrAl2O4： Eu^2＋, Dy^3＋ phosphors. The afterglow luminescence of the samples excited by a 40w fluorescence lamp for 30min can be observed in the dark for more lOh with the naked eyes. It can find wide applications in many fields.

关键词： long afterglow phosphorescence glass StAl2O4 :Eu^2+ Dy^3+,glass frit

Transport mechanism in chemically reactive hybrid nanofluid flow containing gyrotactic micro-organisms over a curved oscillatory surface

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Applied Mathematics and Mechanics(English Edition) 2025年第1期46卷 177-192页

作者： M.NAVEED M.IMRAN T.ASGHAR z.ABBAS Department of Mathematics Division of Science and TechnologyUniversity of Education Department of Mathematics The Islamia University of Bahawalpur

This paper examines the transport analysis, including both heat transfer and mass transfer, in hybrid nanofluid flow containing gyrotactic microorganisms towards a curved oscillatory surface. The influence of magnetic fields is also inspected in terms of their physical characteristics. To depict the phenomena of transport, modified versions of both Fick's and Fourier's laws are used. Additionally, the characteristics of both heterogeneous and homogeneous chemical reactions are also incorporated. Utilizing a curvilinear coordinate system, the flow problem is formulated as partial differential equations(PDEs)for momentum, concentration, microorganism field, and energy. An analytical solution to the obtained flow equations is achieved utilizing the homotopy analysis method(HAM).The effects of significant flow parameters on the pressure and microorganism fields, velocity, oscillation velocity, concentration, and temperature distributions are shown via graphs. Furthermore, the variations in skin friction, mass transfer rate, heat transfer rate, and local motile number due to different involved parameters are presented in tables and are analyzed in detail. Graphical results indicate that the curves of velocity and temperature fields are enhanced as the values of the solid volume fraction variables *** is also verified that the concentration rate field decreases as the values of the homogeneous reaction strength parameter and the radius of curvature parameter increase, and it increases with the Schmidt number and the heterogeneous reaction strength *** outcomes show a favorable response of the motile number to advanced values of the Peclet number, the Schmidt number, the microorganism difference parameter, and the bio-convective Lewis number.

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Effects of temperature and thermally-induced microstructure change on hydraulic conductivity of Boom Clay

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Journal of Rock Mechanics and Geotechnical Engineering 2017年第3期9卷 1-13页

作者： w.z. Chen Y.S. Ma H.D. Yu F.F. Li X.L. Li X. Sillen Research Centre of Geotechnical and Structural Engineering Shandong University Jinan Shandong 250061 China State Key Laboratory of Geomechanics and Geotechnical Engineering Institute of Rock and Soil Mechanics Chinese Academy of Sciences Wuhan 430071 China University of Chinese Academy of Sciences Beijing 100049 China European Underground Research Infrastructure for Disposal of Nuclear waste in Clay Environment EIG Euridice Mol 2400 Belgium ONDRAF/NIRAS Brussel 1210 Belgium

Boom Clay is one of the potential host rocks for deep geological disposal of high-level radioactive nuclear waste in Belgium. In order to investigate the mechanism of hydraulic conductivity variation under complex thermo-mechanical coupling conditions and to better understand the thermo-hydromechanical(THM) coupling behaviour of Boom Clay, a series of permeability tests using temperaturecontrolled triaxial cell has been carried out on the Boom Clay samples taken from Belgian underground research laboratory(URL) HADES. Due to its sedimentary nature, Boom Clay presents acrossanisotropy with respect to its sub-horizontal bedding plane. Direct measurements of the vertical(Kv)and horizontal(Kh)hydraulic conductivities show that the hydraulic conductivity at 80℃ is about 2.4 times larger than that at room temperature(23℃), and the hydraulic conductivity variation with temperature is basically reversible during heatingecooling cycle. The anisotropic property of Boom Clay is studied by scanning electron microscope(SEM) tests, which highlight the transversely isotropic characteristics of intact Boom Clay. It is shown that the sub-horizontal bedding feature accounts for the horizontal permeability higher than the vertical one. The measured increment in hydraulic conductivity with temperature is lower than the calculated one when merely considering the changes in water kinematic viscosity and density with temperature. The nuclear magnetic resonance(NMR) tests have also been carried out to investigate the impact of microstructure variation on the THM properties of clay. The results show that heating under unconstrained boundary condition will produce larger size of pores and weaken the microstructure. The discrepancy between the hydraulic conductivity experimentally measured and predicted(considering water viscosity and density changes with temperature) can be attributed to the microstructural weakening effect on the thermal volume change behaviour of Boom Clay. Based on the ex

关键词： Boom Clay Permeability Thermal effect Anisotropy Microstructure

STUDY ON EROSION RESISTANCE PROPERTIES OF O'-SIALON-BN IN MOLTEN STEEL

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Acta Metallurgica Sinica(English Letters) 2001年第2期14卷 85-90页

作者： Q. zhen, w.z. Ding and w.C. Li (Shanghai Enhanced Laboratory of Ferrometallurgy, Shanghai University, Shanghai 200072, China) (University of Science and Technology Beijing, Beijing 100083, China) Shanghai Enhanced Laboratory of Ferrometallurgy Shanghai University University of Science and Technology Beijing

The erosion resistance properties of O'-Sialon-BN in molten steel are investigated in this work. According to experimental results and theoretical analysis, BN in O'-Sialon-BN plays an important role in the molten steel erosion resistance. And the erosion kinetics of the O'-Sialon-BN composites in molten steel is controlled by two stages: the first one is controlled by the chemical reaction taking place on the interface; the second one is controlled by diffusion. The erosion surface of materials is also investigated with fractal theory. The results show that the fractal dimensions of the erosion surface vary with the erosion time from a linear way to a parabolic way, which is related to the erosion mechanism change from interface chemical reaction to diffusion.

关键词： Corrosion resistance Doping (additives) Fractals Liquid metals Molten materials