检索结果-南通市图书馆

EXPERIMENTAL AND ThEORETICAL INVESTIgATION OF ThE FIRST FOLD CREATION IN ThIN WALLED COLUMNS

在线全文

学校读者我要写书评

暂无评论

Acta Mechanica Solida Sinica 2010年第4期23卷 353-360页

作者： Abbas Niknejad g.h.Liaghat h.Moslemi Naeini A.h.Behravesh Mechanical Engineering Department Yasouj University Faculty of Engineering Payame Noor University (PNU) Mechanical Engineering Department Faculty of EngineeringTarbiat Modares University

In this paper, a theoretical formula is presented to predict the instantaneous folding force of the first fold creation in square and rectangular columns under axial *** rectangular column is a small and single model of honeycombs with square or rectangular *** are based on the analysis of the Basic Folding Mechanism （BFM）.For this purpose, sum of the dissipated energy rate under bending around horizontal and inclined hinge lines and the dissipated energy rate under extensional deformations was equal to the work rate of the external force on the *** final formula obtained in this research, reasonably predicts the instantaneous folding force of single-cell square and rectangular honeycombs instead of the average ***, according to the calculated theoretical relation, the instantaneous folding force of the first fold creation in a square column was sketched versus folding distance and compared to the experimental results, which showed a good correlation.

关键词： dissipated energy rate first fold creation instantaneous folding force thin walled column

Enamel biomimetics—fiction or future of dentistry?

在线全文

学校读者我要写书评

暂无评论

International Journal of Oral Science 2019年第1期11卷 1-9页

作者： Mirali Pandya Thomas g.h.Diekwisch Center for Craniofacial Research and Diagnosis Texas A&M College of Dentistry

Tooth enamel is a complex mineralized tissue consisting of long and parallel apatite crystals configured into decussating enamel rods. In recent years, multiple approaches have been introduced to generate or regenerate this highly attractive biomaterial characterized by great mechanical strength paired with relative resilience and tissue compatibility. In the present review, we discuss five pathways toward enamel tissue engineering,(i) enamel synthesis using physico-chemical means,(ii) protein matrix-guided enamel crystal growth,(iii) enamel surface remineralization,(iv) cell-based enamel engineering, and(v) biological enamel regeneration based on de novo induction of tooth morphogenesis. So far, physical synthesis approaches using extreme environmental conditions such as ph, heat and pressure have resulted in the formation of enamel-like crystal *** methods relying on enamel proteins as templating matrices have aided the growth of elongated calcium phosphate crystals. To illustrate the validity of this biochemical approach we have successfully grown enamel-like apatite crystals organized into decussating enamel rods using an organic enamel protein matrix. Other studies reviewed here have employed amelogeninderived peptides or self-assembling dendrimers to re-mineralize mineral-depleted white lesions on tooth surfaces. So far, cell-based enamel tissue engineering has been hampered by the limitations of presently existing ameloblast cell lines. going forward, these limitations may be overcome by new cell culture technologies. Finally, whole-tooth regeneration through reactivation of the signaling pathways triggered during natural enamel development represents a biological avenue toward faithful enamel regeneration. In the present review we have summarized the state of the art in enamel tissue engineering and provided novel insights into future opportunities to regenerate this arguably most fascinating of all dental tissues.

关键词： complex mineralized Biochemical methods

Thermodynamics under the impact of thermal fluctuations and quasi-normal modes of Euler-heisenberg AdS Bh in the framework of NLED

在线全文

学校读者我要写书评

暂无评论

Chinese Physics C 2023年第11期47卷 145-166页

作者： R.h.Ali g.Abbas Department of Mathematics The Islamia University of BahawalpurBahawalpur Pakistan

We study the impact of thermal fluctuations on the thermodynamics,quasi-normal modes,and phase transitions of an anti-de Sitter Euler-heisenberg black hole(Bh)with a nonlinear electrodynamic *** anti-de Sitter Euler-heisenberg Bh with a nonlinear electrodynamic field is composed of four parameters:the mass,electric charge,cosmological constant,and Euler-heisenberg *** calculate thermodynamic variables such as hawking temperature,entropy,volume,and specific heat,which comply with the first law of ***,we use this Bh to determine the thermodynamics and thermal fluctuations with the Euler-heisenberg parameter to distinguish their effect on uncorrected and corrected thermodynamical *** derive the expression for corrected entropy to study the impact of thermal fluctuation with simple logarithmic corrections on unmodified thermodynamical potentials,including helmholtz energy,pressure,gibbs free energy,and *** Euler-heisenberg parameter improves Bh stability at large ***,we analyze the local stability of the proposed Bh,and the phase shifts of the Bh are also investigated using temperature and specific *** there is a decrease in charge and an increase in r_(+)andα,the temperature shifts from an unstable region to a stable ***,increases in local stability are observed with each of these ***,we use null geodesics to deal with the effects of nonlinear electrodynamics on the quasi-normal modes of the Euler-heisenberg anti-de Sitter *** null geodesics provide the angular velocity and Lyapunov exponent of the photon sphere,which are the same as the real and imaginary parts of the quasi-normal modes in the eikonal limit.

关键词： thermodynamics thermal fluctuation quasi normal modes and phase transition

Extended phase space thermodynamics of black hole with non-linear electrodynamic field

在线全文

学校读者我要写书评

暂无评论

Chinese Physics C 2023年第6期47卷 177-187页

作者： g.Abbas R.h.Ali Department of Mathematics The Islamia University of BahawalpurBahawalpurPakistan

This paper deals with the thermodynamical properties of the black hole formulated in Einstein’s theory of relativity associated with a nonlinear electromagnetic *** transition of the black hole is analyzed using the mass,electric charge,coupling constant,and cosmological *** examine the thermodynamical aspects of exact black hole solutions to compute the black hole mass,temperature,entropy,gibbs free energy,specific heat,and critical exponents in the phase ***,we study the stability of the black hole solution using the specific heat and gibbs free *** examine the first and second phase changes and show a P-V criticality,which is similar to the van der Waals phase *** also examine the equation of the state and the critical exponents.

关键词： non-linear electrodynamic thermodynamics phase transition critical exponents

同方期刊数据库

Effect of Reactivity of Quick Lime on the Properties of hydrated Lime Sorbent for SO_2 Removal

在线全文

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2009年第3期25卷 329-332页

作者： h.g. Shin h. Kim Y.N. Kim h.S. Lee Department of Materials Science and Engineering Seoul National University Material Analysis Team Korea Testing Laboratory School of Materials Science and Engineering Pusan National University

The hydration of quick lime and the sulfation of hydrated lime were carried out for verification of relationship between the reactivity of quick lime and the properties of hydrated lime as a sorbent. The effect of reactivity of quick lime was investigated with the change of calcination temperature and time. Results obtained showed that the temperature rise during the hydration of quick limes varied from 31 to 69℃ with the variation of calcination temperature and time. The specific surface area and the sulfation ability of hydrated lime prepared by hydration of quick lime showed a proportional relationship with the reactivity of quick lime. The hydrated lime which was prepared by hydration of quick lime calcined at 1100℃ had the highest reactivity and showed 41.53 m^2/g of the specific surface area, 0.16 cm^3/g of the pore volume and 87% of the removal efficiency for SO2 removal,

关键词： Reactivity Quick lime hydrated lime Calcination hydration Sorbent

SIMULATION OF 3-D DEFORMATION AND MATERIAL FLOW DURINg ROLL FORgINg PROCESS USINg SYSTEM OF OVAL-ROUND gROOVE

在线全文

学校读者我要写书评

暂无评论

Acta Metallurgica Sinica(English Letters) 2007年第5期20卷 380-384页

作者： g.h. Liu g.S. Ren C.g. Xu Beijing Research Institute of Mechanical ＆ Electrical Technology Beijing 100083 China huazhong University of Science and Technology Wuhan 430074 China

Basing on the analysis of the traits of the roll forging process, a system-model of computer simulation has been established. Three-dimensional rigid-plastic FEM has been used for the simulation of the deformation process in the oval and round pass rolling, including the entering, rolling, and separating stages. The analysis was conducted using the Deform-3D ver.5.0 code. The important information concerned with the deformation area characteristic, material flow, and velocity field has been presented. Otherwise, the location of the neutral plane in the deformation area was shown clearly.

关键词： numerical simulation 3-D deformation roll forging

Thermoelastic Analysis of Non-uniform Pressurized Functionally graded Cylinder with Variable Thickness Using First Order Shear Deformation Theory(FSDT) and Perturbation Method

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Mechanical Engineering 2015年第6期28卷 1149-1156页

作者： KhOShgOFTAR M J MIRZAALI M J RAhIMI g h Faculty of Mechanical Engineering Tarbiat Modares University Department of Mechanical Engineering Faculty of Engineering Arak University Department of Mechanical Engineering Politecnico di Milano

Recently application of functionally graded materials（FgMs） have attracted a great deal of interest. These materials are composed of various materials with different micro-structures which can vary spatially in FgMs. Such composites with varying thickness and non-uniform pressure can be used in the aerospace engineering. Therefore, analysis of such composite is of high importance in engineering problems. Thermoelastic analysis of functionally graded cylinder with variable thickness under non-uniform pressure is considered. First order shear deformation theory and total potential energy approach is applied to obtain the governing equations of non-homogeneous cylinder. Considering the inner and outer solutions, perturbation series are applied to solve the governing equations. Outer solution for out of boundaries and more sensitive variable in inner solution at the boundaries are considered. Combining of inner and outer solution for near and far points from boundaries leads to high accurate displacement field distribution. The main aim of this paper is to show the capability of matched asymptotic solution for different non-homogeneous cylinders with different shapes and different non-uniform pressures. The results can be used to design the optimum thickness of the cylinder and also some properties such as high temperature residence by applying non-homogeneous material.

关键词： non-homogenous cylinder First order Shear Deformation Theory matched asymptotic method perturbation method functionally graded material

Energy transport for ion acoustic waves in a spin polarized quantum plasma

在线全文

学校读者我要写书评

暂无评论

Communications in Theoretical Physics 2020年第1期72卷 124-129页

作者： M Ayub Z Iqbal h A Shah g Murtaza Salam Chair Department of PhysicsG.C.UniversityKatchery RoadLahore 54000Pakistan Department of Physics G.C.UniversityKatchery RoadLahore 54000Pakistan Department of Physics Mirpur University of Science and TechnologyMirpur-10250(AJK)Pakistan

The separate spin evolution quantum hydrodynamics(SSE-QhD)model is used to investigate the energy behavior for ion acoustic waves in degenerate quantum *** results show that the energy flow speed decreases with spin polarization *** is also shown that it decreases with the increasing rate up to a certain range of wave number and then it goes to zero *** is observed that Bohm potential suppresses the energy flow *** is also noticed that the energy flow speed deviates from the group velocity even in the absence of Bohm potential ***,the contribution of of Bohm poential effect in spin polarized plasma reduces the extent of deviation.

关键词： spin polarization quantum plasma ion acoustic wave energy flow speed

Proton-neutron symplectic model description of ^(106)Cd

在线全文

学校读者我要写书评

暂无评论

Chinese Physics C 2024年第3期48卷 169-179页

作者： h.g.ganev Joint Institute for Nuclear Research DubnaRussia Institute of Mechanics Bulgarian Academy of SciencesSofiaBulgaria

In this study,a microscopic shell-model description of the low-lying collective states in the weakly deformed nucleus ^(106)Cd within the recently proposed microscopic version of the Bohr-Mottelson model is provided.A good description of the excitation energies of the lowest ground,γ,andβquasibands is obtained without the adjustable kinetic energy ***,γdegrees of freedom are shown to play a crucial role in the description of spectroscopy of this nucleus.A modified SU(3)SU(3)preserving high-order interaction is used to produce aγ-unstable type of odd-even staggering,observed experimentally between the states of the quasi-γ*** current approach enables the characterization of observed intraband and interband quadrupole *** findings of this study propose an alternative interpretation of the fundamental question regarding the nature of low-energy vibrations,as well as the emergence of deformation and collectivity in weakly deformed atomic nuclei.

关键词： shell-model version of the Bohr-Mottelson model proton-neutron symplectic model Sp(12,R)dynamical algebra quadrupole dynamics