检索结果-南通市图书馆

Microstructures in a Nb-cr-V-W-Ta high entropy alloy during annealing

在线全文

学校读者我要写书评

暂无评论

Journal of Materials science & Technology 2020年第18期52卷 66-72页

作者： s.K.Varma Francelia sanchez c.V.Ramana Department of Metallurgical Materials and Biomaterials EngineeringThe University of Texas at El PasoEl PasoTX 79968-0520USA Mechanical Engineering Department The University of Texas at El PasoEl PasoTX 79968-0520USA

A Nb-cr-V-W-Ta high entropy alloy has been subjected to annealing treatment at 600,700 and 800℃in air for 6 *** different phases have been identified based on their composition in the as received *** annealing treatment does not alter the phase analysis and compositions except for the W-rich phase where minor changes in the composition have been *** is considered as an experimental evidence of sluggish diffusivity associated with *** of phase transformation during the heating and the minimal changes in observed compositions of the phases is an indication of the resistance to diffusion offered by the elements of the high entropy *** electron microscopy(sEM),energy dispersive spectroscopy(EDs)and color X-ray elemental mapping have been used to conduct this research.

关键词： HEA Microstructures in a Nb-cr-V-W-Ta high entropy alloy during annealing

Interfacial fracture analysis for a two-dimensional decagonal quasi-crystal coating layer structure

在线全文

学校读者我要写书评

暂无评论

Applied Mathematics and Mechanics(English Edition) 2021年第11期42卷 1633-1648页

作者： Minghao ZHAO cuiying FAN c.s.LU Huayang DANG school of Mechanics and safety Engineering Zhengzhou UniversityZhengzhou 450001China school of Mechanical Engineering Zhengzhou UniversityZhengzhou 450001China school of civil and Mechanical Engineering Curtin UniversityWestern Australia 6845Australia

The interface crack problems in the two-dimensional(2D)decagonal quasicrystal(Qc)coating are theoretically and numerically investigated with a displacement discontinuity *** 2D general solution is obtained based on the potential *** analogy method is proposed based on the relationship between the general solutions for 2D decagonal and one-dimensional(1D)hexagonal *** to the analogy method,the fundamental solutions of concentrated point phonon displacement discontinuities are obtained on the *** using the superposition principle,the hypersingular boundary integral-differential equations in terms of displacement discontinuities are determined for a line interface ***,Green’s functions are found for uniform displacement discontinuities on a line *** oscillatory singularity near a crack tip is eliminated by adopting the Gaussian distribution to approximate the delta *** stress intensity factors(sIFs)with ordinary singularity and the energy release rate(ERR)are ***,a boundary element method is put forward to investigate the effects of different factors on the fracture.

关键词： two-dimensional(2D)decagonal quasi-crystal(Qc)coating interface crack analogy method displacement discontinuity stress intensity factor(sIF) energy release rate(ERR)

On vibration analysis of functionally graded carbon nanotube reinforced magneto-electro-elastic plates with different electro-magnetic conditions using higher order finite element methods

在线全文

学校读者我要写书评

暂无评论

Defence Technology（防务技术） 2021年第1期17卷 287-303页

作者： M.Vinyas D.Harursampath s.c.Kattimani Nonlinear Multifunctional composites Analysis and Design(NMcAD)Laboratory Department of Aerospace EngineeringIndian Institute of ScienceBangalore560012India Department of Mechanical Engineering National Institute of Technology KarnatakaSurathkal575025India

This article deals with evaluating the frequency response of functionally graded carbon nanotube reinforced magneto-electro-elastic(FG-cNTMEE)plates subjected to open and closed electro-magnetic circuit *** this regard finite element formulation has been *** plate kinematics adjudged via higher order shear deformation theory(HsDT)is considered for *** equations of motion are obtained with the help of Hamilton’s principle and solved using condensation *** is found that the convergence and accuracy of the present FE formulation is very good to address the vibration problem of FG-cNTMEE *** the first time,frequency response analysis of FG-cNTMEE plates considering the effect of various circuit conditions associated with parameters such as cNT distributions,volume fraction,skew angle,aspect ratio,length-to-thickness ratio and coupling fields has been carried *** results of this article can serve as benchmark for future development and analysis of smart structures.

关键词： carbon nanotube Magneto-electro-elastic Higher order shear deformation theory coupled frequency Electro-magnetic conditions

sulphur Mustard Induced Oxidative stress and Its Prevention by sodium 2, 3-Dimercapto Propane sulphonic Acid (DMPs) in Mice

在线全文

学校读者我要写书评

暂无评论

Biomedical and Environmental sciences 2000年第3期13卷 225-232页

作者： s．c．PANT R.VIJAYARAGHAVAN 等 DivisionofPharmacologyandToxicology DefenceResearchandDevelopmentEstablishmentJhansiRoadGwalior－474002India DivisionofPharmacologyandToxicology DefenceResearchandDevelopmentEstabl

sulphur mustard [bis(2 chloro ethyl) sulfide] (sM), a bifunctional alkylating agent has been frequently used as a chemical warfare agent. In the present study, the effects of sodium 2 3 dimercaptopropane sulphonic acid (DMPs) on some biochemical and histological parameters in mice, exposed to 1/4Lc 50 concentration of sM vapor (10.5 mg/m\+3) were examined over a period of seven days. Exposure of sM resulted in a significant loss of blood, hepatic and pulmonary glutathione (GsH) and an elevation of hepatic and pulmonary oxidized glutathione (GssG). These biochemical changes were accompanied by a number of histopathological alterations. The most prominent was congestion and degeneration in viscera and obliteration of chromatin material. These biochemical and histopathological changes were less marked in animals pre administered with DMPs followed by DMPs exposure indicating some protective value of the thiol (DMPs) against sM induced oxidative injury in mice.

关键词： Animals Female Mice Mustard Gas Oxidative stress Unithiol

Enhancement of luminescence intensity and spectroscopic analysis of Eu^(3+) activated and Li^+ charge-compensated Bi_2O_3 nanophosphors for solid-state lighting

在线全文

学校读者我要写书评

暂无评论

Journal of Rare Earths 2019年第4期37卷 356-364页

作者： s.Ashwini s.c.Prashantha RamachANDra Naik H.Nagabhushana Department of Physics Channabasaveshwara Institute of Technology Research center Department of Science East West Institute of Technology Department of Physics New Horizon College of Engineering cNR Rao center for Advanced Materials Tumkur University

The present work reports the synthesis, characterization, photoluminescence and photocatalytic activity of Eu^(3+)(1 mol%-11 mol%) doped and Li^+(0.5 mol%-5 mol%) co-doped Bi_2 O_3 nanophosphors(NPs) by sonochemical method. The average particle size was estimated using powder X-ray diffraction(PXRD)and transmission electron microscopy(TEM) and is found to be in the range of 30-35 nm. The scanning electron microscopy(sEM) images were highly dependent on sonication time and concentration of epigallocatechin gallate(EGcG) bio-surfactant. The energy gap of doped and co-doped Bi_2 O_3 nanophosphors was estimated using Kubelka-Munk(K-M) function and is found to be in the range of2.9-3.08 eV. The effect of Li+ co-doping on luminescence of optimized Bi_2 O_3:Eu^(3+) was studied and is found about more than 3 fold enhancement of emission intensity. Judd-Ofelt parameters(Ω_2, Ω_4 and Ω_6).transition probabilities(A_T), quantum efficiency(η), luminescence lifetime(τ_(rad)), color chromaticity coordinates(cIE) and correlated color temperature(ccT) values were estimated from the emission spectra and are discussed in detail. The estimated cIE chromaticity co-ordinates are very close to the NTsc(National Television standard committee) standard value of red emission. The synthesized NPs show excellent photocatalytic activity of acid red-88 under UV-light irradiation, which can degrade 98.1% in60 min. The decreasing electron-hole pair recombination rate with quick electron transfer ability is predominantly ascribed to the balance between crystallite size, morphology, band gap, defects, surface area, etc. These results show a light for the use of sonochemical route of Bi_2 O_3:Eu^(3+):Li^+ in solid state display and photocatalytic applications.

关键词： Bi2O3:Eu3+:Li+ sonochemical Photoluminescence cIE n ccT Photocatalysis Rare earths

Artificial intelligence and liver transplantation:Looking for the best donor-recipient pairing

在线全文

学校读者我要写书评

暂无评论

Hepatobiliary & Pancreatic Diseases International 2022年第4期21卷 347-353页

作者： Javier Briceno Rafael calleja césar Hervás Unit of Liver Transplantation Department of General SurgeryHospital Universitario Reina SofíaCórdobaSpain Maimónides Institute of Biomedical Research of córdoba(IMIBIc) CórdobaSpain Department of computer sciences and Numerical Analysis Universidad de CórdobaCórdobaSpain

Decision-making based on artificial intelligence(AI)methodology is increasingly present in all areas of modern *** recent years,models based on deep-learning have begun to be used in organ *** into account the huge number of factors and variables involved in donor-recipient(DR)matching,AI models may be well suited to improve organ ***-based models should provide two solutions:complement decision-making with current metrics based on logistic regression and improve their *** of classifiers could be used to address this ***,not all of them are really useful for D-R ***,in the decision to assign a given donor to a candidate in waiting list,a multitude of variables are handled,including donor,recipient,logistic and perioperative *** these last two,some of them can be inferred indirectly from the team’s previous *** groups of AI models have been used in the D-R matching:artificial neural networks(ANN)and random forest(RF).The former mimics the functional architecture of neurons,with input layers and output *** algorithms can be uni-or *** general,ANNs can be used with large databases,where their generalizability is ***,they are models that are very sensitive to the quality of the databases and,in essence,they are black-box models in which all variables are ***,these models do not allow to know safely the weight of each *** the other hand,RF builds decision trees and works well with small *** addition,they can select top variables as with logistic ***,they are not useful with large databases,due to the extreme number of decision trees that they would generate,making them *** ANN and RF allow a successful donor allocation in over 80%of D-R pairing,a number much higher than that obtained with the best statistical metrics such as model for end-stage liver disease,balance of risk

关键词： Donor-recipient matching Artificial intelligence Deep learning Artificial neural networks Random forest Liver transplantation outcome

customer segment Prediction on Retail Transactional Data Using K-Means and Markov Model

在线全文

学校读者我要写书评

暂无评论

Intelligent Automation & soft computing 2023年第4期36卷 589-600页

作者： A.s.Harish c.Malathy sRM Institute of science and Technology KattankuluthurChennai603203Tamil NaduIndia

Retailing is a dynamic business domain where commodities and goods are sold in small quantities directly to the *** deals with the end user customers of a supply-chain network and therefore has to accommodate the needs and desires of a large group of customers over varied *** volume and volatility of the business makes it one of the prospectiveﬁelds for analytical study and data *** is also why customer segmentation drives a key role in multiple retail business decisions such as marketing budgeting,customer targeting,customized offers,value proposition *** segmentation could be on various aspects such as demographics,historic behavior or preferences based on the use *** this paper,historic retail transactional data is used to segment the custo-mers using K-Means clustering and the results are utilized to arrive at a transition matrix which is used to predict the cluster movements over the time period using Markov Model *** helps in calculating the futuristic value a segment or a customer brings to the *** marketing designs and budgeting can be implemented using these *** study is speciﬁcally useful for large scale marketing in domains such as e-commerce,insurance or retailers to segment,proﬁle and measure the customer lifecycle value over a short period of time.

关键词： K-means retail analytics clustering cluster prediction Markov chain transition matrix RFM model customer segmentation segment prediction Markov model segment proﬁling

Effect of process parameters on depth of penetration and topography of AZ91 magnesium alloy in abrasive water jet cutting

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Magnesium and Alloys 2018年第4期6卷 366-374页

作者： c A Niranjan s srinivas M Ramachandra Department of Mechanical Engineering BMS College of EngineeringBengaluru-India

In the present study,the influence of dynamic process parameters such as water pressure,traverse speed and abrasive mass flow rate on depth of penetration and surface topography in high strength AZ91 magnesium alloy were investigated using Abrasive Water Jet(AWJ)cutting *** parameters were varied at 3 levels and influences of each parameter on penetration ability were identified using analysis of variance(ANOVA).contribution of water pressure and traverse speed on jet penetration found higher compared to abrasive mass flow *** projector was used to measure depth of *** features and topography of cut surfaces were examined using scanning Electron Microscopy(sEM).Micro cutting and ploughing were observed on the top and bottom portion of the cut which were similar to that of modes of deformation in other ductile materials like aluminium and *** roughness of cut surfaces was measured using Taylor Hobson surface roughness *** roughness found higher at higher traverse speeds and lower at lower traverse *** study also highlights the suitability of AWJ cutting technology for cutting magnesium and its alloys.

关键词： AZ91 magnesium alloy Depth of penetration Profile projector Topography

Fatigue Behaviour of Naval steel Under seawater Environmental and Variable Loading conditions

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Iron and steel Research International 2011年第5期18卷 64-69页

作者： c Gheorghies L Palaghian s Baicean M Buciumeanu s ciortan Department of Physics University "Dunarea de Jos" of Galati Department ofMechanical Engineering University "Dunarea de Jos" of Galati

The way to characterize the behaviour of a naval steel grade E36 subjected to the corrosive fatigue process is investigated. The tests were carried out by bending fatigue of plate specimens with thickness of 10 mm in the corrosive environment consisting of an aqueous solution of 3.5% of Nacl which is similar to seawater. Experimental results show that the principal mechanism of degradation of the superficial layer is based on the pit evolution,evidenced by electrochemical,micro and macro structural timely changes such as evolution of electrode potential,evolution of current density,polarization resistance,anodic and cathodic parameters,and dislocation density evolution.

关键词： naval steel fatigue pitting corrosion structure