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Chinese Physics b 2018年第10期27卷 231-239页

作者： j P Singh v t Pham t Hayat S jafari F E Alsaadi b K Roy Department of Electrical Engineering National Institute of Technology Silchar 788010 India School of Electronics and telecommunications Hanoi University of Science and Technology 01 Dai Co Viet Hanoi Viet Nam Department of Mathematics Faculty of Science King Abdulaziz University Jeddah 21589 Saudi Arabia Department of Mathematics Quaid-I-Azam University Islamabad 44000 Pakistan Ambikar University of technology Tehran 15875-4413Iran Department of Information technology Faculty of Computing and IT King Abdulaziz University Jeddah Saudi Arabia

this paper reports a new simple four-dimensional（4 D） hyperjerk chaotic system. the proposed system has only one stable equilibrium point. Hence, its strange attractor belongs to the category of hidden attractors. the proposed system exhibits various dynamical behaviors including chaotic, periodic, stable nature, and coexistence of various attractors. Numerous theoretical and numerical methods are used for the analyses of this system. the chaotic behavior of the new system is validated using circuit implementation. Further, the synchronization of the proposed systems is shown by designing an adaptive integrator backstepping controller. Numerical simulation validates the synchronization strategy.

关键词： new hyperjerk chaotic system stable equilibrium hidden attractors adaptive backstepping control synchronization

Influence of tiO_2 on the electrochemical performance of pasted typeβ-nickel hydroxide electrode in alkaline electrolyte

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journal of Energy Chemistry 2016年第1期25卷 41-48页

作者： b.Shruthi b.j.Madhu v.bheema Raju Department of Chemistry Dr. Ambedkar Institute of Technology Post Graduate Department of Physics Government Science College Department of Chemistry Dayananda Sagar College of Engineering

Nickel hydroxide was used as the positive electrode material in rechargeable alkaline batteries, which plays a significant role in the field of electric energy storage devices. β-nickel hydroxide（β-Ni（OH）2 ） was prepared from nickel sulphate solution using potassium hydroxide as a precipitating agent. Pure β-phase of nickel hydroxide was confirmed from XRD and Ft-IR studies. the effects of tiO2 additive on the β-Ni（OH）2 electrode performance are examined. the structure and property of the tiO2 added β-Ni（OH）2 were characterized by XRD, tG-DtA and SEM analysis. A pasted–type electrode is prepared using nickel hydroxide powder as the main active material on a nickel sheet as a current collector. Cyclic voltammetry and electrochemical impedance spectroscopy studies were performed to evaluate the electrochemical performance of the β-Ni（OH）2 and tiO2 added β-Ni（OH）2 electrodes in 6 M KOH electrolyte. Anodic（Epa） and cathodic（Epc）peak potentials are found to decrease after the addition of tiO 2 into β-Ni（OH）2 electrode material. Further,addition of tiO2 is found to enhance the reversibility of the electrode reaction and also increase the separation of the oxidation current peak of the active material from the oxygen evolution current. Compared with pure β-Ni（OH）2 lectrode,tiO2 added β-Ni（OH）2 electrode is found to exhibit higher proton diffusion coefficient（D） and lower charge transfer resistance. these findings suggest that the tiO2 added β-Ni（OH）2 electrode possess improved electrochemical properties and thus can be recognized as a promising candidate for the battery electrode applications.

关键词： Nickel hydroxide Electrode material thermogravimetric analysis Electrochemical properties Impedance spectroscopy

vented Individual Patient(vIP)Hoods for the Control of Infectious Airborne Diseases in Healthcare Facilities

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Engineering 2022年第8期8卷 126-132页

作者： j.Patel F.McGain t.bhatelia S.Wang b.Sun j.Monty v.Pareek CSIRO Energy MelbourneVIC 3169Australia Western Health MelbourneVIC 3021Australia School of Public Health The University of SydneySydneyNSW 2006Australia Centre for Integrated Critical Care The University of MelbourneMelbourneVIC 3010Australia the Western Australian School of Mines:Minerals Energy and Chemical EngineeringCurtin UniversityPerthWA 6102Australia Department of Mechanical Engineering City University of Hong KongHong Kong 999077China Department of Mechanical Engineering The University of MelbourneMelbourneVIC 3010Australia

by providing a means of separating the airborne emissions of patients from the air breathed by healthcare workers(HCWs),vented individual patient(vIP)hoods,a form of local exhaust ventilation(LEv),offer a new approach to reduce hospital-acquired infection(HAI).Results from recent studies have demonstrated that,for typical patient-emitted aerosols,vIP hoods provide protection at least equivalent to that of an N95 *** a mask,hood performance can be easily monitored and HCWs can be alerted to failure by *** appropriate use of these relatively simple devices could both reduce the reliance on personal protective equipment(PPE)for infection control and provide a low-cost and energy-efficient form of protection for hospitals and *** the development and deployment of vIP hoods has been accelerated by the coronavirus disease 2019(COvID-19)pandemic,these devices are currently an immature *** this review,we describe the state of the art of vIP hoods and identify aspects in need of further development,both in terms of device design and the protocols associated with their *** broader concept of individual patient hoods has the potential to be expanded beyond ventilation to the provision of clean conditions for individual patients and personalized control over other environmental factors such as temperature and humidity.

关键词： COvID-19 vented individual patient hood Airborne transmission Healthcare worker Infectious disease

Effect of bagasse ash reinforcement on the wear behaviour of Al-Cu-Mg/bagasse ash particulate composites

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Acta Metallurgica Sinica(English Letters) 2010年第2期23卷 81-89页

作者： v.S. Aigbodion S.b. Hassan G.b. Nyior t. Ause Department of Metallurgical and Materials Engineering Ahmadu Bello University

the effect of bagasse ash （bAp） particle reinforcement on the wear behavior of Al-Cu- Mg alloy has been studied. bagasse ash particles were varied from 0 wt pct-10 wt pct with interval of 2 wt pct. Unlubricated pin-on disc tests were conducted to examine the wear behaviour of the aluminium alloy/bagasse ash particulate composites. the tests were conducted at varying loads, from 5 to 20 N and sliding speeds of 1.26 m/s, 2.51 m/s, 3.77 m/s and 5.02 m/s for a constant sliding distance of 5000 m. the results showed that the wear rates of the A1-Cu-Mg/bAp composites are lower than that of the matrix alloy and further decrease with increasing bagasse ash content. Wear rate increases as the sliding speed and applied load increase. the microstructure of the worn surface revealed that a large amount of plastic deformation appeared on the surface of the unreinforced alloy. While bagasse ash reinforced Al-Cu-Mg alloy showed worn out surface that is not smooth, and grooves, scratches and parallel lines were observed. A combination of adhesion and delamination wear was in operation. these results show that improve wear properties is achievable for the aluminium alloy by the addition of bagasse ash particles as reinforcement material.

关键词： Al-Cu-Mg alloy bagasse ash Composites Load Sliding speed and Wear

Microstructure, properties and hot workability of M300 grade maraging steel

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Defence technology（防务技术） 2018年第1期14卷 51-58页

作者： K.v.A.Chakravarthi N.t.b.N.Koundinya S.v.S.Narayana Murty b.Nageswara Rao Materials and Mechanical Entity Vikram Sarabhai Space Centre Research scholar Department of Mechanical Engineering K L University Department of Metallurgical Engineering and Materials Science Indian Institute of Technology Department of Mechanical Engineering K L University

this paper presents isothermal uniaxial compression test results of M300 grade maraging steel over a wide range of temperatures(900 e1200℃) and strain rates(0.001 e100 s^(-1)) to examine hot deformability and concurrent microstructural evolution. Processing map is generated and indicated the optimum processing parameters in the temperature range of 1125℃-1200℃ and strain rate range of 0.001 e0.1 s^(-1). High values of the efficiency of power dissipation, microstructural observations and EbSD results indicate softening mechanism to be the occurrence of dynamic recrystallisation. Material constants in a constitutive relation are evaluated from the flow stress data useful in computer modelling.

关键词： Activation energy Constitutive relation Hot deformation M300 grade maraging steel Processing map

Suzuki Reaction of Aryl bromides Using a Phosphine-Free Magnetic Nanoparticle-Supported Palladium Catalyst

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催化学报 2011年第11期32卷 1667-1676页

作者： Nghia t. bUI trung b. DANG Ha v. LE Nam t. S. PHAN Department of Chemical Engineering HCMC University of Technology VNU-HCM 268 Ly Thuong Kiet Distriet 10 Ho Chi Minh City Viet Nam

A palladium catalyst immobilized on superparaganetic nanoparticles was prepared with a palladium loading of 0.30 mmol/g. the catalyst was characterized using X-ray diffraction, scanning electron microscopy, transmission electron microscopy, vibrating sample magnetometry, thermogravimetric analysis, Fourier transform infrared, atomic absorption spectrophotometry, and nitrogen adsorption. the immobilized palladium catalyst was an efficient catalyst without added phosphine ligands for the Suzuki cross-coupling reaction of several aryl bromides with phenylboronic acid. the recovery of catalyst was simply by magnetic decantation in the presence of a magnet. the immobilized palladium catalyst can be reused many times without significant degradation in catalytic activity. No leaching of active palladium species into the reaction solution was detected.

关键词： superparamagnetic nanoparticle Suzuki reaction palladium aryl bromide

Power management unit chip design for automobile active-matrix organic light-emitting diode display module

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journal of Central South University 2009年第4期16卷 621-628页

作者： KIM j H PARK j H KIM j H CAO t v LEE t Y bAN H j YANG K KIM H G HA P b KIM Y H Department of Electronic Engineering Changwon National University 9 Sarim-Dong Changwon 641-773 Korea Denso PS Electronics Corporation 47 Seongsan-Dong Changwon 641-315 Korea

A power management unit （PMU） chip supplying dual panel supply voltage, which has a low electro-magnetic interference （EMI） characteristic and is favorable for miniaturization, is designed. A two-phase charge pump circuit using external pumping capacitor increases its pumping current and works out the charge-loss problem by using bulk-potential biasing circuit. A low-power start-up circuit is also proposed to reduce the power consumption of the band-gap reference voltage generator. And the ring oscillator used in the ELvSS power circuit is designed with logic devices by supplying the logic power supply to reduce the layout area. the PMU chip is designed with MagnaChip＇s 0.25 μ high-voltage process. the driving currents of ELvDD and ELvSS are more than 50 mA when a SPICE simulation is done.

关键词： DC-DC converter AMOLED charge pumping power management unit (PMU) dual panel supply voltage

Inhibition Effects of Chloroquinolines on Corrosion of Mild Steel in Hydrochloric Acid Solution

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journal of Iron and Steel Research International 2014年第8期21卷 804-808页

作者： A.v.Shanbhag t.v.venkatesha b.M.Praveen S.b.Abd Hamid Department of Chemistry S.D.M.College Department of P.G.Studies and Research in Chemistry Kuvempu University Department of Chemistry Srinivas School of Engineering Nanotechnology and Catalysis Research Centre(NANOCAt) IPSUniversity of Malaya

the corrosion inhibition efficiencies of four compounds namely N-[（1E）-（2-chloroquinolin-3-yl）methylene]-N-phenylamine（CQMA）,N-（1E）-（2-chloroquinolin-3-yl）methylene]-N-（4-fluorophenyl）amine（CQMFA）,N-（4-chloro phenyl）-N-[（1E）-（2-chloroquinolin-3-yl）methylene]amine（CQMCA）,and N-（4-bromo phenyl）-N-[（1E）-（2-chloroquinolin-3-yl）methylene]amine（CQMbA）on mild steel corrosion in hydrochloric acid media were investigated using mass loss,potentiodynamic polarization and electrochemical impedance *** all the studied inhibitors the inhibition efficiency values were found to increase with increasing concentration up to 5.00×10-4 mol·*** electron microscopic technique showed the formation of a thick film on the steel surface in the presence of inhibitors.

关键词： adsorption isotherm corrosion inhibition mild steel chloroquinoline mixed inhibitor

buckling analysis of functionally graded material(FGM) sandwich truncated conical shells reinforced by FGM stiffeners filled inside by elastic foundations

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Applied Mathematics and Mechanics(English Edition) 2016年第7期37卷 879-902页

作者： D.v.DUNG L.K.HOA b.t.tHUYEt N.t.NGA Faculty of Mathematics Mechanics and Informatics Vietnam National University Faculty of basic Science Military Logistic AcademyHanoi Faculty of Mining Hanoi University of Mining and Geology

An analytical solution for buckling of an eccentrically stiffened sandwich truncated conical shell is investigated. the shell consists of two functionally graded material （FGM） coating layers and a core layer which are metal or ceramic subjected to an axial compressive load and an external uniform pressure. Shells are reinforced by stringers and rings, in which the material properties of shells and stiffeners are graded in the thickness direction following a general sigmoid law distribution. two models of coated shell-stiffener arrangements are investigated. the change of the spacing between stringers in the meridional direction is taken into account. A couple set of three-variable- coefficient partial differential equations in terms of displacement components are solved by the Galerkin method. A closed-form expression for determining the buckling load is obtained. the numerical examples are presented and compared with previous works.

关键词： functionally graded material (FGM) sandwich truncated conical shell,stiffener elastic foundation buckling analysis

Effects of variable fluid properties on the thin film flow of Ostwald-de Waele fluid over a stretching surface

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journal of Hydrodynamics 2013年第1期25卷 10-19页

作者： vAjRAvELU K. PRASAD K. v. RAjU b. t. Department of Mathematics Department of Mechanical Material and Aerospace Engineering University of Central Florida Department of Mathematics Central College Campus Bangalore University

We investigate, in this paper, the effects of thermo-physical properties on the flow and heat transfer in a thin film of a power-law liquid over a horizontal stretching surface in the presence of a viscous dissipation. the fluid properties, namely the fluid viscosity and the fluid thermal conductivity, are assumed to vary with temperature. Using a similarity transformation, the governing partial differential equations with a time dependent boundary are converted into coupled non-linear Ordinary Differential Equations （ODEs） with variable coefficients. Numerical solutions of the coupled ODEs are obtained by a finite difference scheme known as the Keller-box method. Results for the velocity and temperature distributions are presented graphically for different values of the pertinent parameters. the effects of unsteady parameter on the skin friction, the wall temperature gradient and the film thickness are presented and analyzed for zero and non-zero values of the temperature-dependent thermo-physical properties. the results obtained reveal many interesting features that warrant further study on the non-Newtonian thin film fluid flow phenomena, especially the shear-thinning phenomena.

关键词： thin film flow variable fluid properties viscous dissipation finite difference method