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Transformation of Voltage Mode Filter Circuit Based on Op-Amp to Circuit Based on CCII

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journal of Electronic Science and Technology 2015年第1期13卷 60-67页

作者： Thouraya Ettaghzouti néjib Hassen Kamel Besbes Micro-Electronics and Instrumentation Laboratory University of Monastir

In this paper, firstly we demonstrate the use of nodal admittance matrix to convert a low-pass band-pass filter based on operational amplifier（op-amp） to a circuit based on a second-generation current conveyor（CCII）. This technique allows us to get eight presumptions of filter circuits. Secondly, we present a novel architecture circuit of CCII, which can operate at low supply voltage of ±0.75 V. All simulations are performed by TSPICE models. The simulation results show that this circuit has a low impedance at terminal X（r X=1.01 Ω）, a very high input impedance at terminal Y, and wide bandwidth current and voltage. The center frequency of the proposed filter is variable on the interval [157 k Hz, 196 MHz].

关键词： Filter nodal admittance matrix norator nullator

DIFFUSIVE-DISPErSIVE TrAVELInG WAVES AnD KInETIC rELATIOnS IV. COMPrESSIBLE EULEr EQUATIOnS

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Chinese Annals of Mathematics,Series B 2003年第1期24卷 17-34页

作者： n. BEDjAOUI P.G.LEFLOCH Centre de Mathematiques Appliquees & Centre national de la recherche Scientifique UMR 7641 Ecole Polytechnique 91128 Palaiseau Cedex France. INSSET Universite de Picardie 48 rue Raspail 02109 Saint-Quentin France.Centre de Mathematiques Appliquees & Centre National de la Recherche Scientifique UMR 7641 Ecole Polytechnique 91128 Palaiseau Cedex France.

The authors consider the Euler equations for a compressible fluid in one space dimensionwhen the equation of state of the fluid does not fulfill standard convexity assumptions andviscosity and capillarity effects are taken into account. A typical example of nonconvex con-stitutive equation for fluids is Van der Waals' equation. The first order terms of these partialdifferential equations form a nonlinear system of mixed (hyperbolic-elliptic) type. For a class ofnonconvex equations of state, an existence theorem of traveling waves solutions with arbitrarylarge amplitude is established here. The authors distinguish between classical (compressive) andnonclassical (undercompressive) traveling waves. The latter do not fulfill Lax shock inequali-ties, and are characterized by the so-called kinetic relation, whose properties are investigatedin this paper.

关键词： Elasto dynamics Phase transitions Hyperbolic conservation law Diffusion Dispersion Shock wave Undercompressive Entropy inequality Kinetic relation

BEST APPrOXIMATIOn FOr WEIErSTrASS TrAnSFOrM COnnECTED WITH SPHErICAL MEAn OPErATOr

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Acta Mathematica Scientia 2012年第2期32卷 455-470页

作者： L.T.rachdi n.Msehli Département de Math'ematiques Facult'e des Sciences de Tunis2092 El-ManarTunisia Département de Mathématiques et d'informatique Institut National des Sciences Appliquées et de Technologie de Tunis1080 TunisTunisia

Using reproducing kernels for Hilbert spaces, we give best approximation for Weierstrass transform associated with spherical mean operator. Also, estimates of extremal functions are checked.

关键词： Weierstrass transform spherical mean operator best approximation repro-ducing kernel extremal function

Effect of COOH-functionalized SWCnT addition on the electrical and photovoltaic characteristics of Malachite Green dye based photovoltaic cells

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journal of Semiconductors 2014年第12期35卷 32-37页

作者： S.Chakraborty n.B.Manik Condensed Matter Physics research Center Department of Physics Jadavpur University

We report the effect of COOH-functionalized single walled carbon nanotubes（COOH-SWCnT） on the electrical and photovoltaic characteristics of Malachite Green（MG） dye based photovoltaic cells. Two different types of photovoltaic cells were prepared, one with MG dye and another by incorporating COOH-SWCnT with this dye. Cells were characterized through different electrical and photovoltaic measurements including photocurrent measurements with pulsed radiation. From the dark current–voltage（I–V） characteristic results, we observed a certain transition voltage（Vth/ for both the cells beyond which the conduction mechanism of the cells change sharply. For the MG dye, Vthis 3.9 V whereas for COOH-SWCnT mixed with this dye, Vthdrops to 2.7 V. The device performance improves due to the incorporation of COOH-SWCnT. The open circuit voltage and short circuit current density change from 4.2 to 97 m V and from 108 to 965 A/cm2 respectively. Observations from photocurrent measurements show that the rate of growth and decay of the photocurrent are quite faster in the presence of COOH-SWCnT. This observation indicates a faster charge separation processes due to the incorporation of COOHSWCnT in the MG dye cells. The high aspect ratio of COOH-SWCnT allows efficient conduction pathways for the generated charge carriers.

关键词： MG dye COOH-SWCnT photovoltaic devices charge transport

Surface alloying of Al films/Ti substrate based on high-current pulsed electron beams irradiation

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rare Metals 2014年第2期33卷 155-160页

作者： Xian-Xiu Mei jian-Qiang Fu Xiao-na Li V.P.rotshtein n.n.Koval Teng-Cai Ma Key Laboratory of Materials Modification by Laser Ion and Electron Beams Ministry of Education Dalian University of Technology Institute of High Current Electronics Siberian Branch Russian Academy of Sciences

Ti–Al surface alloy was fabricated using a cyclic pulsed liquid-phase mixing of predeposited 100 nm Al film with a-Ti substrate by low-energy high-current electron beam. Electron probe micro-analysis（EPMA）,grazing incidence X-ray diffraction analysis（GIXrD）,transmission electron microscopy（TEM）, and nanoindentation were used to investigate the characterization of Ti–Al surface alloy. The experimental results show that the thickness of alloy layer is ＊3 lm, and the content of Al in the ＊1 lm thickness surface layer is ＊60 at%. The tetragonal TiAl and TiAl2intermetallics were synthesized at the top surface, which have nanocrystalline *** main phase formed in the ＊2.5 lm thick surface is TiAl, and there are few TiAl2and Ti3Al phase for the *** is enhanced in the alloyed layer. The nanohardness of Ti–Al surface alloy increased significantly compared with a-Ti substrate due to the nanostructure and enhanced dislocation. Since the e-beam remelted repeatedly, the Ti–Al surface alloy mixed sufficiently with Ti substrate. Moreover, there is no obvious boundary between the alloyed layer and substrate.

关键词： Ti–Al surface alloy layer High-current pulse electron beam irradiation Microstructural characterization

Long-term patterns in Iberian hare population dynamics in a protected area(Doñana national Park)in the southwestern Iberian Peninsula:Effects of weather conditions and plant cover

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Integrative Zoology 2017年第1期12卷 49-60页

作者： Francisco CArrO ramón C.SOrIGUEr Doñana Biological Station(CSIC) the Monitoring Team on Natural Resources and Processes of the Doñana Biological Station Ethology and Biodiversity Conservation SevillaSpain

The Iberian hare(Lepus granatensis)is a widely distributed endemic species in the Iberian *** improve our knowledge of its population dynamics,the relative abundance and population trends of the Iberian hare were studied in the autumns of 1995-2012 in a protected area(Doñana national Park)by spotlighting in 2 different habitats:marshland and *** average relative abundance was 0.38 hare/km(SD=0.63)in the marshland and 3.6 hares/km(SD=4.09)in *** Iberian hare population exhibited local interannual fluctuations and a negative population trend during the study period(1995-2012).The results suggest that its populations are in *** flooding of parts of the marshland in june,july and October favor hare abundance in the *** abundance in the marshland increases as the flooded surface area increases in *** effects are more pronounced if the rains are early(October)and partially flood the *** contrast,when marsh grasses and graminoids are very high and thick(as measured using the aerial herbaceous biomass[biomass marshland]as a proxy),the abundance of hares decreases dramatically as does the area of the marsh that is flooded(in november).

关键词： Doñana Iberian Peninsula Lepus granatensis population dynamics trends

The Mathematical Analysis for Peristaltic Flow of Hyperbolic Tangent Fluid in a Curved Channel

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Communications in Theoretical Physics 2013年第6期59卷 729-736页

作者： S.nadeem E.n.Maraj Department of Mathematics Quaid-i-Azam University

In the present paper, we have investigated the peristaltic flow of hyperbolic tangent fluid in a curved channel. The governing equations of hyperbolic tangent fluid model for curved channel are derived including the effects of curvature. The highly nonlinear partial differential equations are simplified by using the wave frame transformation,long wave length and low reynolds number assumptions. The reduced nonlinear partial differential equation is solved analytically with the help of homotopy perturbation method (HPM). The physical features of pertinent parameters have been discussed by plotting the graphs of pressure rise and stream functions.

关键词： tangent hyperbolic fluid curved channel peristaltic flow HPM

Binary Multifold Encryption Technique for Complex Cloud Systems

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Computer Systems Science & Engineering 2022年第9期42卷 1199-1213页

作者： n.Ansgar Mary T.Latha Department of Information and Technology St.Xavier’s Catholic College of EngineeringTamil Nadu629001India Department of Electronics and Communication Engineering St.Xavier’s Catholic College of EngineeringTamil Nadu629001India

Data security is a major cloud computing issue due to different usertransactions in the system. The evolution of cryptography and cryptographic analysis are regarded domains of current research. deoxyribo nucleic acid (DnA) cryptography makes use of DnA as a sensing platform, which is then manipulated usinga variety of molecular methods. Many security mechanisms including knowledgebased authentication, two-factor authentication, adaptive authentication, multifactorauthentication and single password authentication have been deployed. These cryptographic techniques have been developed to ensure confidentiality, but most ofthem are based on complex mathematical calculations and equations. In the proposed approach, a novel and unique Hybrid helix scuttle-deoxy ribo nucleic acids(HHS-DnA) encryption algorithm has been proposed which is inspired by DnAcryptography and Helix scuttle. The proposed HHS-DnA is a type of multifold binary version of DnA (MF-BDnA). The major role of this paper is to present a multifold HHS-DnA algorithm to encrypt the cloud data assuring more security with lesscomplexity. The experimentation is carried out and it reduces the encryption time,cipher text size, and improves throughput. When compared with previous techniques, there is a 45% improvement in throughput, 37% fast in encryption time,54.67% cipher text size. The relevant experimental results and foregoing analysisshow that this method is of good robustness, stability, and security.

关键词： Cryptography cloud network deoxy ribo nucleic acid(DnA) encryption security cloud service provider(CSP)

nUMErICAL SIMULATIOnS FOr A VArIABLE OrDEr FrACTIOnAL CABLE EQUATIOn

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Acta Mathematica Scientia 2018年第2期38卷 580-590页

作者： A.M.nAGY n.H.SWEILAM Department of Mathematics Faculty of Science Benha University Department of Mathematics Faculty of Science Cairo University

In this article, Crank-nicolson method is used to study the variable order fractional cable equation. The variable order fractional derivatives are described in the riemann- Liouville and the Griinwald-Letnikov sense. The stability analysis of the proposed technique is discussed. numerical results are provided and compared with exact solutions to show the accuracy of the proposed technique.

关键词： Crank-nicolson method variable order fractional cable equation stability anal-ysis