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Implementing the Node Based smoothed Finite Element Method as User Element in Abaqus for Linear and Nonlinear Elasticity

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Computers, Materials & Continua 2019年第8期61卷 481-502页

作者： s.Kshrisagar A.Francis j.j.Yee s.Natarajan C.K.Lee Integrated Modelling and simulation Lab Department of Mechanical EngineeringIndian Institute of Technology MadrasChennai600036India The Department of Architectural Engineering Dong-A UniversityS04-0302Engineering 237Nakdongdaero 550beon-gilSaha-guBusan49315Korea National Research Center for Disaster-free&safe Ocean City Dong-A UniversityS04-0311-3Engineering 237Nakdong-daero 550beon-gilSaha-guBusan49315Korea

In this paper,the node based smoothed-strain Abaqus user element(UEL)in the framework of finite element method is *** basic idea behind of the node based smoothed finite element(NsFEM)is that finite element cells are divided into subcells and subcells construct the smoothing domain associated with each node of a finite element cell[Liu,Dai and Nguyen-Thoi(2007)].Therefore,the numerical integration is globally performed over smoothing *** is demonstrated that the proposed UEL retains all the advantages of the NsFEM,i.e.,upper bound solution,overly soft stiffness and free from locking in compressible and nearly-incompressible *** this work,the constant strain triangular(CsT)elements are used to construct node based smoothing domains,since any complex two dimensional domains can be discretized using CsT *** additional challenge is successfully addressed in this *** efficacy and robustness of the proposed work is obtained by several benchmark problems in both linear and nonlinear *** developed UEL and the associated files can be downloaded from https://***/nsundar/NsFEM.

关键词： smoothed finite element method(sFEM) node based sFEM(NsFEM) linear and nonlinear elasticity Abaqus UEL(user elements) compressible and nearlyincompressible materials

Improved mechanical properties of siC fiber reinforced silica-based ceramic cores fabricated by stereolithography

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journal of Materials science & Technology 2022年第21期116卷 161-168页

作者： W.Zheng j.M.Wu s.Chen K.B.Yu j.Zhang Y.s.shi state Key Laboratory of Materials Processing and Die&Mould Technology School of Materials Science and EngineeringHuazhong University of Science and TechnologyWuhan 430074China Engineering Research Center of Ceramic Materials for Additive Manufacturing Ministry of EducationWuhan 430074China

silica-based ceramic cores have been widely used to fabricate aero-engine hollow blades due to their moderate high temperature mechanical properties and excellent *** this study,silica-based ceramics with siC fiber addition were prepared via stereolithography,and the influence of siC fiber content on mechanical properties of the obtained silica-based ceramics was *** the increase of siC fiber content,linear shrinkage gradually decreased,while room temperature flexural strength and high temperature flexural strength first increased and then *** siC fiber content increased to 4.0 wt%,linear shrinkage was reduced to 0.62%resulting from the oxidation of ***,room temperature flexural strength was improved from 11.79 MPa to 23.83 MPa and high temperature flexural strength was enhanced from 15.64 MPa to 34.62 MPa with 4.0 wt%siC fiber addition due to the reinforcement of fibers and the enhancedβ-cristobalite content,which meets the need of ceramic ***,it demonstrates the capability of fabricating high-performance and high-precision silica-based ceramic cores reinforced by siC fibers via stereolithography for rapid manufacturing of hollow blades.

关键词： silica-based ceramic cores stereolithography siC fiber Mechanical properties Hollow blades

synthesis of 1,8-dioxooctahydroxanthenes utilizing PMA-siO_2 as an efficient reusable catalyst

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Chinese Chemical Letters 2008年第7期19卷 771-774页

作者： P.srihari s.s.Mandal j.s.s.Reddy R.srinivasa Rao j.s.Yadav Organic Division-I Indian Institute of Chemical TechnologyHyderabad 500007India

PMA-siO2 has been utilized as an efficient catalyst system in preparation of 1,8-dioxooctahydroxanthenes.

关键词： Heteropolyacids Xanthenes Pigments Dyes silica gel

PMA-siO_2 catalyzed synthesis of β-keto enol ethers

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Chinese Chemical Letters 2008年第7期19卷 767-770页

作者： P.srihari s.s.Mandal j.s.s.Reddy R.srinivasa Rao j.s.Yadav Organic Division-I Indian Institute of Chemical TechnologyHyderabad 500007India

An efficient conversion of β-diketones into corresponding β-keto enol ethers with catalytic amount of PMA-siO2 has been achieved.

关键词： β-Keto enol ethers β-Diketones

swampland ds conjecture in mimetic f(R,T)gravity

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Communications in Theoretical Physics 2022年第8期74卷 101-115页

作者： s Noori Gashti j sadeghi s Upadhyay M R Alipour Department of Physics Faculty of Basic SciencesUniversity of Mazandaran PO Box 47416-95447BabolsarIran Department of Physics K.L.S.CollegeNawadaBihar 805110India Department of Physics Magadh UniversityBodh GayaBihar 824234India Inter-University Centre for Astronomy and Astrophysics(IUCAA) PuneMaharashtra 411007India school of Physics Damghan UniversityDamghan ***Iran

In this paper,we study a theory of gravity called mimetic f(R,T)in the presence of swampland ds *** this purpose,we introduce several inflation solutions of the Hubble parameter H(N)from f(R,T)=R+δT gravity model,in which R is Ricci scalar,and T denotes the trace of the energy–momentum ***,δand N are the free parameter and a number of e-fold,*** we calculate quantities such as potential,Lagrange multiplier,slow-roll,and some cosmological parameters such as nsand *** we challenge the mentioned inflationary model from the swampland ds *** discuss the stability of the model and investigate the compatibility or incompatibility of this inflationary scenario with the latest Planck observable data.

关键词： mimetic f(R,T)gravity Lagrange multiplier swampland conjecture

soil carbon characterization along the profile of two forest soils under Quercus pyrenaica

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journal of Forestry Research 2020年第2期31卷 591-600页

作者： A.P.fernandez-Getino j.L.Alonso-Prados M.I.santin-Montanya UPF-DTEVPF Instituto Nacional de Investigacion y Tecnologia Agraria y AlimentariaINIACtra.A Corunakm 7.528040 MadridSpain Dpto.Proteccion Vegetal Instituto Nacional de Investigacion y Tecnologia Agraria y AlimentariaINIACtra.A Corun akm 7.528040 MadridSpain

In light of concerns over climate change and increasing levels of CO2 in the atmosphere,it is of importance to investigate soil organic matter in Mediterranean forests at a profile ***-depth studies of the organic fraction are also of interest to improve understanding of carbon balance and to facilitate modelling of carbon fixation in forest *** research evaluates the relationships between diverse parameters such as colour,content,and form of soil organic matter(sOM).Two Quercus pyrenica ecosystems with soils classified as inceptisols with a xeric or dry moisture regime,and developed under a Mediterranean climate in spain,were used to characterize sOM through the complete sequence of layers of the soil *** differentiating factor between the two ecosystems was slope *** was done using characteristics of humic substances(Hs)as indicators of sOM turnover in *** analysis was used to further characterize the humic *** soil colour measurements are a tool for soil type classification and soil organic carbon prediction,the relation between Hs colour measured by reflection and by transmission was determined in order to establish a relationship between measurement *** analysis and colour provided evidence of a different level of stabilization of Hs from both soils,and between the different *** of humic acids was found to be greater in deeper horizons than in the surface *** inverse relationship between Hs colour measured by reflection and by transmission was *** soils showed a clear trend in which horizons presenting lower absorbance numbers showed higher figures of hue and value.A more marked accumulation of humified compounds was found in pedons,(the smallest unit or volume of soil that contains all the soil types),in the less steep *** might be explained in terms of the physiographic position affecting infiltration behavior and exposure to runoff.

关键词： Organic matter turnover Colour humic substance(Hs)by reflection Colour Hs by transmission Humification index Mediterranean Quercus species

sTUDY OF EXPLOsIVE VAPORIZATION OF LD11R ALUMINUMALLOY DURING ELECTRON BEAM DEEP PENETRATION

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Acta Metallurgica sinica(English Letters) 2000年第6期13卷 1119-1124页

作者： Wang, Y.j. jia, s.j. Liu, F.j. Chen, X.F. NKL of EDB process. Technol. Beijing 100024 China

High-power-density electron beam with single pulse was performed on the LD11R aluminum alloy. The electron beam was focused on three typical positions. For each case, the distribution of the solute concentration at the cavity bottom solid-liquid interface was investigated by using the 'rapidly fixing' method. The interaction of the beam and solute atoms was analyzed. A new mechanism of explosive vaporization was proposed based on the present results. The occurrence of this explosive vaporization source was discussed.

关键词： Electron beam welding Vaporization

Environmental impact of radionuclide migration in groundwater from a low intermediate level radioactive waste repository

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journal of Environmental sciences 2001年第2期13卷 180-184页

作者： j s Wang Z F Yang s s Li Z M Wang Institute of Environmental sciences Beijing Normal University State Key Joint Laboratory of Environmental Simulation and Pollution Control Beijing 100875 China.

The radionuclide migration from a certain Chinese repository with low-intermediate level radioactive solid waste is studied. The migration in groundwater is analyzed and computed in detail. Under presumption of normal releasing, or the bottom of the repository has been marinated for one month with precipitation reaching 600 mm once and a 6 m aerated zone exists, a prediction for 7 radionuclides is conducted. It shows that the aerated zone is the primary barrier for migration. The migration for radionuclides 60Co, 137Cs, 90sr, 63Ni, etc. will be retarded in it within 500 years. The concentration of 239Pu will be decreased by amount of 6 order. Only 3H and 14C can migrate through the aerated zone. The radionuclides that go through the aerated zone and enter the aquifer will exist in spring, stream and sea. Based on this, the intake dose by residents in different age group resulting from drinking contaminated spring water, eating seafood is calculated. The results showed that the impact of the repository to the key resident group is lower than the limit in national repository regulation standard. This complies with the repository management target.

关键词： intermediate level radioactive waste repository Environmental impact of radionuclide migration in groundwater from a low

Maneuvering Modeling and simulation of AUV Dynamic systems with Euler-Rodriguez Quaternion Method

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China Ocean Engineering 2013年第3期27卷 403-416页

作者： C.W.Chen j.s.Kouh j.F.Tsai Department of science Engineering and Ocean Engineering National Taiwan University

The purpose of this study is to develop maneuvering models and systems of a simulator to improve the motion performance of autonomous underwater vehicles （AUVs） at the preliminary design stages in advance. The AUVs simulation systems based on the standard submarine equations of motion in six-degree-of-freedom （6-DOF） integrated with the Euler-Rodriguez quaternion method for representing singularity-free AUV attitude and time-saving calculation, and with a nonlinear control model for maneuvering and depth control simulations, time-marching in the fourth-order Runge-Kutta scheme. For validation of the simulation codes, results of the IsiMI AUV open-loop tests including turning test and zigzag test as well as an AUV simulator on the basis of Euler-angle method were used to compare with the quaternion-based AUV simulator. The computational results from the proposed simulator agree well with those from both the IsiMI AUV experiments and the Euler-angle based simulations. Additionally, a new maneuvering procedure, namely ＂put-out＂ was implemented to test directional stability for a large-scale AUV in the proposed AUV simulator that can be considered for vehicles in space as well as in constrained planes.

关键词： autonomous underwater vehicle (.4 UV) Euler-Rodriguez quaternion hydrodynamics maneuvering systemdynamics