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A micro-Structure Dependent Buckling Analysis of Partially-Cracked Generally Orthotropic Plate under Thermal Domain

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Advances in Applied mathematics and mechanics 2023年第1期15卷 244-266页

作者： Ankur Gupta Shashank Soni n.K.Jain Department of mechanical Engineering National Institute of TechnologyRaipurChhattisgarh 492010India

In this work,a non-classical analytical approach for buckling analysis of partially cracked generally orthotropic plate is proposed under the thermal *** derivation for the governing equation is based on the non-classical approach using Kirchhoff’s thin plate theory and the modified couple stress *** effect of fibre orientation on critical buckling temperature is incorporated by considering the coefficients of mutual *** spring model is applied with some modifications to formulate all the crack terms while the thermal effects are introduced in form of thermal in-plane moments and *** final governing equation is solved using Galerkin’s method and the relation for critical buckling temperature as affected by fibre orientation is *** variation of critical buckling temperature as affected by fibre orientation for different values of crack length,crack location and length scale parameter is ***,the effect of fibre orientation on fundamental frequency under the thermal domain is analysed.

关键词： Orthotropic plate fibre orientation crack microstructure thermal domain

Tribological Characterization of Hybrid metal matrix Composites Processed by Powder metallurgy

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Acta metallurgica Sinica(English Letters) 2017年第8期30卷 781-790页

作者： m. megahed m. A. Attia m. Abdelhameed A. G. El-Shafei Department of mechanical Design and Production Engineering Faculty of EngineeringZagazig UniversityP.O.Box 44519ZagazigEgypt

Aluminum （Al）-based aluminum oxide （Al2O3） and silicon carbide （SIC） particles hybrid metal matrix com- posites were processed by powder metallurgy technique, followed by sintering at 500 ℃ and then hot extrusion. The tribological properties of these composites with different weight fractions of Al2O3 and SiC were investigated; extrusion process significantly reduces the extent of porosity after cold compaction and sintering processes. Hybridization of the two reinforcements improved hardness and wear resistance of the composites. With an increase in SiC content, hardness was increased and consequently the wear resistance was enhanced also. Scanning electron microscopy observations show a better interfacial bond between matrix and reinforcements and a better distribution of the reinforcements.

关键词： Hybrid metal matrix composite Powder metallurgy Abrasive wear Hardness Porosity

A glance on the effects of temperature on axisymmetric dynamic behavior of multiwall carbon nanotubes

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Acta mechanica Sinica 2012年第3期28卷 720-728页

作者： S.T.Talebian m.Tahani m.H.Abolbashari S.m.Hosseini Department of mechanical Engineering Faculty of EngineeringFerdowsi University of Mashhad Department of mechanical Engineering Lean Production Engineering Research CenterFerdowsi University of Mashhad Department of Industrial Engineering Faculty of EngineeringFerdowsi University of Mashhad

In this paper the effects of temperature on the radial breathing modes （RBms） and radial wave propaga- tion in multiwall carbon nanotubes （mWCnTs） are inves- tigated using a continuum model of multiple elastic isotropic shells. The van der Waals forces between tubes are simulated as a nonlinear function of interlayer spacing of mWCnTs. The governing equations are solved using a finite element method. A wide range of innermost radius-to-thickness ratio of mWCnTs is considered to enhance the investigation. The presented solution is verified by comparing the results with those reported in the literature. The effects of temperature on the van der Waals interaction coefficient between layers of mWCnTs are examined. It is found that the variation of the van der Waals interaction coefficient at high temperature is sensible. Subsequently, variations of RBm frequencies and radial wave propagation in mWCnTs with temperatures up to 1 600 K are illustrated. It is shown that the thick mWC- nTs are more sensible to temperature than the thin ones.

关键词： multiwall carbon nanotube Radial wave propa-gation. Radial breathing modes - van der Waals force. Ther-mal effects

Fracture Toughness and microcracks on natural Apophyllite Crystals

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Journal of materials Science & Technology 1998年第2期14卷 156-160页

作者： Dhar, P.R. Bamzai, K. Kotru, P.n. Dept. of Physics University of Jammu Jammu-180004 India

Results on fracture toughness of natural apophyllite crystals when they were subjected to impact were presented. The morphology of the cracks and fracture has been studied. It was found that the crack formation does not show any anisotropic property and remains the same whatever may be the orientation of the crystal. The average values of the fracture toughness K//c and brittleness index, as determined from measurements of crack length, were estimated to be 0.107 g mu m** minus **3**/**2 and 4.19 mu m** minus **1**/**2 respectively for the a(100) plane. The yield strength for a(100), P(111) and C(001) planes of apophyllite crystals for lower loads is 2250, 2160 and 1840 mPa and for higher loads is 1510, 1600 and 1430 mPa respectively. (Edited author abstract) 7 Refs.

关键词： Crystals

Coverless Video Steganography Based on Frame Sequence Perceptual Distance mapping

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Computers, materials & Continua 2022年第10期73卷 1571-1583页

作者： Runze Li Jiaohua Qin Yun Tan neal n.Xiong College of Computer Science and Information Technology Central South University of Forestry&TechnologyChangsha410004China Department of mathematics and Computer Science Northeastern State UniversityTahlequah74464OKUSA

most existing coverless video steganography algorithms use a particular video frame for information *** methods do not reflect the unique sequential features of video carriers that are different from image and have poor *** propose a coverless video steganography method based on frame sequence perceptual distance *** this method,we introduce Learned Perceptual Image Patch Similarity(LPIPS)to quantify the similarity between consecutive video frames to obtain the sequential features of the *** we establish the relationship map between features and the hash sequence for information *** addition,the mongoDB database is used to store the mapping relationship and speed up the index matching speed in the information hiding *** results show that the proposed method exhibits outstanding robustness under various noise *** with the existing methods,the robustness to Gaussian noise and speckle noise is improved by more than 40%,and the algorithm has better practicability and feasibility.

关键词： Coverless steganography frame sequence perception distance

Role of nitric oxide in the maintenance of pluripotency and regulation of the hypoxia response in stem cells

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World Journal of Stem Cells 2015年第3期7卷 605-617页

作者： Amparo Beltran-Povea Estefania Caballano-Infantes Carmen Salguero-Aranda Franz martín Bernat Soria Francisco J Bedoya Juan R Tejedo Gladys m Cahuana Andalusian Center for molecular Biology and Regenerative medicine-University Pablo de Olavide CIBERDEM RED-TERCEL 41092 Seville Spain Andalusian Center for molecular Biology and Regenerative medicine (CABImER) -Fundación Progreso y Salud CIBERDEM RED-TERCEL 41092 Seville Spain

Stem cell pluripotency and differentiation are global processes regulated by several pathways that have been studied intensively over recent years. nitric oxide(nO) is an important molecule that affects gene expression at the level of transcription and translation and regulates cell survival and proliferation in diverse cell types. In embryonic stem cells nO has a dual role, controlling differentiation and survival, but the molecular mechanisms by which it modulates these functions are not completely defined. nO is a physiological regulator of cell respiration through the inhibition of cytochrome c oxidase. many researchers have been examining the role that nO plays in other aspects of metabolism such as the cellular bioenergetics state, the hypoxia response and the relationship of these areas to stem cell stemness.

关键词： Pluripotency Differentiation nitric oxide metabolism Hypoxia Stem cell

The Alpe Arami Story: Triumph of Data over Prejudice

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Journal of Earth Science 2010年第5期21卷 731-743页

作者： Harry W Green II Larissa F Dobrzhinetskaya Krassimir n Bozhilov Institute of Geophysics and Planetary Physics Department of Earth Sciences University of California at Riverside Riverside CA92521 USA Department of Earth Sciences University of California at Riverside Riverside CA92521 USA

The Alpe Arami garnet peridotite of the Southern Swiss Alps is associated with eclogites and included within quartzofeldspathic gneisses. Controversy has swirled around the depth of origin of this massif since the 1970s when application of the newly-developed technique of thermobarometry suggested a depth of last equilibration of greater than 120 kin. Such controversy accelerated in 1996 when we reported microstructural evidence of extensive precipitation of ilmenite and spinel from olivine and proposed a much greater depth of origin. Subsequent experiments showed that it was possible to dissolve the observed amount of TiO2 in olivine, but only at depths in excess of 300 kin, agreeing with the earlier proposal. In 1999 we added new, independent, evidence concerning exsolution of high-pressure clinoenstatite from diopside that in-and-of-itself required a depth of origin in excess of 250 km. Subsequently, we also added evidence from the surrounding eclogites of very high pressures and experimental evidence that the pyroxenes included in the amoeboid garnets of this rock had exsolved from a majoritic parent at perhaps even greater pressures. In refutation of the first two of these observations, suggestions were made that （i） we had made a serious error in our estimate of how much ilmenite was present in olivine （and therefore how much TiO2 had been dissolved in olivine）; （ii） the ilmenite had not been exsolved from olivine but former titanian clinohumite had been present and broke down to yield the ilmenite; （iii） the pyroxene exsolved from diopside had been high-temperature clinoenstatite. In all three of these cases, the alternatives offered were claimed to be accommodated at low pressures. Here we review the essence of this controversy and show that the only scenario that can explain all of the data is the one that we originally proposed; indeed, the more recent data have strongly supported that interpretation and pushed the minimum origin of the massif to depths ap

关键词： Alpe Arami TiO2 in olivine high-pressure clinoenstatite deep exhumation.

Fusion material Studies Relating to Safety in Russia in 2002

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Plasma Science and Technology 2004年第5期6卷 2496-2502页

作者： B.n.Kolbasov m.I.Guseva B.I.Khripunov Y.V.martvnenkc P.V.Romanov S.A.Lelekhov S.A.Bartenev Russian Research Centre "Kurchatov Institute" Kurchatov Sq. 1 123182 Moscow Russia RF Federal Agency for Atomic Energy Staromonetnyj pereulok 26 109180 Moscow Russia V. G. Khlopin Radium Institute 2nd Murinsky avenue 28 194021 St.-Petersburg Russia

The paper is a summary of Russian material studies performed in frames of activi-ties aiming at substantiation of safety of the International Thermonuclear Experimental Reactor(ITER)after *** sputtering of tungsten by 5 eV deuterons was revealed at temper-atures above 1150℃.mechanism of globular films formation was further *** of tritium permeation into vacuum vessel coolant confirmed the acceptability of vacuum vessel cooling system for removal of the decay *** most dangerous accident with high-current are in toroidal superconducting magnets able to burn out a bore up to 0.6 m in diameter in the cryostat vessel was *** reprocessing of V-Cr-Ti alloy and its purification from activation products down to a contact dose rate of~10μSv/h was developed.

关键词： fusion reactor materials plasma-materials interaction vanadium and vanadium alloys

A Study of multifractal Spectra and Renyi Dimensions in 14.5A GeV/c <sup>28</sup>Si-nucleus Collisions

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Journal of modern Physics 2014年第14期5卷 1288-1293页

作者： n. Ahmad A. Kamal m. m. Khan &nbsp Hushnud A. Tufail Applied Science Section University Polytechnic Aligarh Muslim University Aligarh India Department of Applied Physics Aligarh Muslim University Aligarh India Department of Basic Science Deanship of Prepratory Year Umme Al-Qura University Makkah KSA Department of Physics Aligarh Muslim University Aligarh India

A systematic analysis of the data on 14.5A GeV/c 28Si-nucleus collisions is carried out to investigate the behaviours of Renyi dimensions, Dq and multifractal Spectral Function, f(αq). The Renyi dimensions, Dq are observed to decrease with increasing order of the moments, q. However, the multifractal Spectra are concave downwards with their maxima occurring around αq =1.21±0.01. A continuous curve representing multifractal Spectral Function, f(αq), characterizes manifestation of fluctuations in the rapidity space.

关键词： nucleus-nucleus Cillisions multifractality and non-Statistical Fluctuatuons