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EVOlUTION OF ROUGHNESS ON THE SURFACE OF A STRAINED ElASTIC MATERIAl DUE TO STRESS-DRIVEN SURFACE DIFFUSION

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Acta Mechanica Sinica 1994年第1期10卷 16-26页

作者： l.b.freund Division of Engineering Brown University Providence RI 02912 USA

The free energy of a stressed crystal is assumed to consist of elastic strain energy and surface energy, and the chemical potential for surface diffusion at constant temperature is obtained under this assumption. A gradient in chemical potential results in diffusive mass transport along the surface. The result is applied in considering the phenomena of instability of a flat surface in a stressed material under fluctuations in surface shape, and the transient evolution of surface roughness due to an initial perturbation in the nearly flat free surface of the material, both under plane strain conditions.

关键词： elastic material surface energy diffusion

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金属在应力波加载条件下的起裂

兵器材料科学与工程 1985年第5期 61-69页

作者： l.S.Costin J.Duffy l.b.freund 孙琦清

在所有的工程构件中都存在有缺陷,而不管它们是天然的还是在加工过程中形成的。因此,防止构件的断裂设计已成为普遍的实际问题。大多数情况下,把材料起裂看作是发生在静态或准静态加载条件下。然而,在实践中的许多加载条件不能作为准静... 详细信息

在所有的工程构件中都存在有缺陷,而不管它们是天然的还是在加工过程中形成的。因此,防止构件的断裂设计已成为普遍的实际问题。大多数情况下,把材料起裂看作是发生在静态或准静态加载条件下。然而,在实践中的许多加载条件不能作为准静态加载条件来处理,在该情况下,必须考虑物质的惯性以及它的速率敏感性。使用对加载

关键词：加载率敏感性试件静态实验亚临界裂纹扩展起裂点裂纹张开位移应力波加载条件

black hole shadows in Einstein-bel-Robinson gravity

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Chinese Physics C 2024年第5期48卷 272-283页

作者： b.Hamil b.C.lütfüoğlu laboratoire de Physique Mathématique et Subatomique Facultédes Sciences ExactesUniversitéConstantine 1ConstantineAlgeria Department of Physics University of Hradec KrálovéRokitanského 6250003 Hradec KrálovéCzechia

Gravity models given by higher-order scalar curvature corrections are believed to bear important consequences. Einstein-bel-Robinson (EbR) gravity with quartic curvature modification motivated Sajadi et al. to explore static spherically symmetric black hole solutions using perturbative methods. In this study, inspired by their work, we investigate AdS black hole shadows in EbR gravity and demonstrate how the gravity parameter alters the energy emission rate. Finally, we address the same problem in the presence of plasma, because the black holes are thought to be surrounded by a medium that changes the geodesic of photons.

关键词： black hole shadows Einstein-bel-Robinson gravity plasma

Optimal Control of Service Rates of Discrete-Time(s,Q)Queueing-Inventory Systems with Finite buffer

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Journal of Systems Science and Systems Engineering 2024年第3期33卷 261-280页

作者： l.Iniya b.Sivakumar G.Arivarignan School of Mathematics Madurai Kamaraj UniversityMaduraiTamilnaduIndia Department of Statistics Manonmaniam Sundaranar UniversityTirunelveliTamilnaduIndia

This article,we develop an optimal policy to control the service rate of a discrete time queueing-inventory system with finite *** customers arrive according to a bernoulli process and the service time for the customers are *** the buffer size attains its maximum,any arriving new customers are considered to be *** customers are served one by one according to FCFS rule and each customers request random number of *** inventory is replenished according to a(s,Q)inventory policy with geometric lead *** main objectives of this article are to determine the service rates to be employed at each slot so that the long run expected cost rate is minimized for fixed inventory level and fixed buffer size and to minimize the expected waiting time for a fixed inventory level and fixed buffer *** problems are modelled as Markov decision *** establish the existence of a stationary policy and employ linear programming method to find the optimal service *** provide some numerical examples to illustrate the behaviour of the model.

关键词： Queueing-inventory system discrete time batch demand-Markov decision process

Weighted Probability Density Estimator with Updated bandwidths

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Journal of Systems Science & Complexity 2024年第2期37卷 886-906页

作者： WU Yi YU Wei WANG Xuejun PRAKASA RAO b l S School of big Data and Artificial Intelligence Chizhou UniversityChizhou 247000China School of big Data and Statistics Anhui UniversityHefei 230601China CR Rao Advanced Institute of Mathematics Statistics and Computer ScienceHyderabad 500046India

In this paper,the authors study a class of weighted version of probability density *** is shown that the weighted estimator contains some existing estimators of probability density,no matter they are recursive or *** statistical results including weak consistency,strong consistency,rate of strong consistency,and asymptotic normality are established under some mild ***,the random weighted estimator is also *** numerical simulations and a real data analysis are presented to study the numerical performances of the estimators.

关键词： Asymptotic normality consistency numerical simulation probability density real data analysis updated bandwidths weighted estimator

Semi-analytical investigation of heat transfer in a porous convective radiative moving longitudinal fin exposed to magnetic field in the presence of a shape-dependent trihybrid nanofluid

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Applied Mathematics and Mechanics(English Edition) 2024年第1期45卷 197-216页

作者： C.G.PAVITHRA b.J.GIREESHA M.l.KEERTHI Department of PG Studies and Research in Mathematics Kuvempu UniversityShankaraghatta 577451India Department of Mathematics and Statistics M.S.Ramaiah University of Applied SciencesBengaluru 560058India

The thermal examination of a non-integer-ordered mobile fin with a magnetism in the presence of a trihybrid nanofluid(Fe_3O_4-Au-Zn-blood) is carried out. Three types of nanoparticles, each having a different shape, are considered. These shapes include spherical(Fe_3O_4), cylindrical(Au), and platelet(Zn) configurations. The combination approach is utilized to evaluate the physical and thermal characteristics of the trihybrid and hybrid nanofluids, excluding the thermal conductivity and dynamic viscosity. These two properties are inferred by means of the interpolation method based on the volume fraction of nanoparticles. The governing equation is transformed into a dimensionless form, and the Adomian decomposition Sumudu transform method(ADSTM) is adopted to solve the conundrum of a moving fin immersed in a trihybrid nanofluid. The obtained results agree well with those numerical simulation results, indicating that this research is reliable. The influence of diverse factors on the thermal overview for varying noninteger values of γ is analyzed and presented in graphical representations. Furthermore, the fluctuations in the heat transfer concerning the pertinent parameters are studied. The results show that the heat flux in the presence of the combination of spherical, cylindrical, and platelet nanoparticles is higher than that in the presence of the combination of only spherical and cylindrical nanoparticles. The temperature at the fin tip increases by 0.705 759% when the value of the Peclet number increases by 400%, while decreases by 11.825 13% when the value of the Hartman number increases by 400%.

关键词： convection radiation moving longitudinal fin Adomian decomposition Sumudu transform method(ADSTM) trihybrid nanofluid magnetic field

The Making of a Health Profession:How Chinese Medicine became a Nationally Registered Allied Health Profession in Australia

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Chinese Medicine and Culture 2024年第1期7卷 51-62页

作者： John l McDonald Judy b James School of Chinese Medicine Endeavour College of Natural HealthSouthport 4215Australia Acupuncture Now Australia Brisbane 4120Australia

In 2012, traditional Chinese medicine(TCM) practitioners in Australia became nationally-registered allied health professionals in three categories: acupuncturist, Chinese herbal medicine practitioner, and Chinese herbal medicine dispenser. Australia was the first Western country to introduce national registration for Chinese medicine, followed by Portugal and, recently, New Zealand. The practice of TCM in Australia can be traced back to the beginning of Chinese immigration to Australia during the Victorian Gold Rush which began in the 1850s. The process which led to national registration commenced in the early 1970s with the establishment of the first acupuncture courses. Decades of gradual development of courses from unaccredited part-time diplomas to accredited bachelor degrees, and the development, by the profession, of national consensus on educational standards were essential elements in the process which led to registration. Professional associations, such as the Australian Acupuncture and Chinese Medicine Association ltd.(AACMA), also developed a framework of professional selfregulation, including Codes of Ethics, Codes of Conduct, ongoing professional development requirements and Infection Control Guidelines, and provided leadership in the development of the profession. After decades of tribalism and division within the TCM profession, the National Academic Standards Committee brought almost all stakeholders together to reach a consensus on the Australian Guidelines for Traditional Chinese Medicine Education which were published by AACMA in 2001. Professional associations also collaborated on joint submissions to the government in support of registration, which was introduced first in the state of Victoria in 2000, and subsequently became national in 2012. Despite national registration, some barriers still remain, and professional associations continue to lobby the federal government for inclusion in Medicare, chronic disease management scheme, and Veterans

关键词： Acupuncture Chinese medicine Registration Regulation Education Standards Australia TCM

Knotting ligands to control metal coordination geometry

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Science China Chemistry 2024年

作者： Fabien b.l.Cougnon Department of Chemistry and Nanoscience Centre University of Jyv?skyl?

Zinc is a metal of particular importance for life [1]. It is the most abundant transition metal in biological systems after iron and contributes both structural and catalytic roles to many cellular processes. The properties of ZnII, unlike those of any other first-row transition metal ions, explain its biological relevance. Due to its filled d-shell orbitals, ZnIIis redox-stable, has a ligand-field energy stabilization of zero and, consequently, no typical coordination number and geometry. Zinc metalloproteins exploit these features to carry a broad range of chemical reactions in mild *** metalloenzymes, unsaturated ZnIIcentres often act as redox-stable lewis acids. The protein backbone provides a highly preorganized environment around the metal centre and accompanies the changes in coordination geometry occurring as substrate transformation proceeds, thereby modulating the metal reactivity.

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In situ TEM investigation of electron irradiation and aging-induced high-density nanoprecipitates in an Mg-10Gd-3Y-1Zn-0.5Zr alloy

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Journal of Magnesium and Alloys 2024年第5期12卷 1841-1853页

作者： M.lv H.l.Ge Q.Q.Jin X.H.Shao Y.T.Zhou b.Zhang X.l.Ma Shenyang National laboratory for Materials Science Institute of Metal ResearchChinese Academy of Sciences72 Wenhua RoadShenyang 110016China School of Materials Science and Engineering University of Science and Technology of ChinaShenyang 110016China Materials Science and Engineering Research Center Guangxi University of Science and TechnologyLiuzhou 545006China

In-situ electron irradiation and aging are applied to introduce high-density precipitates in an Mg-10Gd-3Y-1Zn-0.5Zr(GWZ1031K,wt.%)alloy to improve the *** results show that the hardness of the Mg alloy after irradiation for 10 h and aging for 9 h at 250℃ is 1.64 GPa,which is approximately 64% higher than that of the samples before being *** is mainly attributed to γ'precipitates on the basal plane after irradiation and the high-density nanoscale β'precipitates on the prismatic plane after aging,which should be closely related to the irradiation-induced homogenous *** latter plays a key role in precipitation *** result paves a way to improve the mechanical properties of metallic materials by tailoring the precipitation through irradiation and aging.

关键词： Mg alloy Electron beam irradiation Hardening Precipitates In-situ TEM