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Liu L.-C.,Xinyang Normal University | Yang X.,Shanghai University
Yantu Lixue/Rock and Soil Mechanics | Year: 2011

As we know, the soil has viscoelastic characteristic, the control equations of saturated soil described by fractional derivative model are established based on the theories of porous media and theories of fractional derivatives, in which the soil is regarded as porous medium filled with water; and the stress-strain relationship is described by fractional derivative viscoelastic model for considering the viscoelastic properties of soil skeleton. The vertical coupled vibration of a pile in a saturated soil described by fractional derivative model is investigated by introducing the potential functions and separation of variables method under the three-dimensional axisymmetric condition; and the influences of the model parameters on the vertical vibration of a pile in saturated soil is analyzed. The results indicate that the control equations of the saturated soil described by fractional derivative model has a wider application; and the model parameters has great influences on the vertical vibration of a pile in saturated soil.

Yang M.-H.,Xinyang Normal University | Han Z.-Q.,Dalian University of Technology
Nonlinear Analysis: Real World Applications | Year: 2012

In this paper, we study the existence and multiplicity results for the nonlinear SchrödingerPoisson systems -Δu+V(x)u+K(x)φ(x)u=f(x,u), in R 3,-Δφ=K(x) u2,in R 3. Under certain assumptions on V, K and f, we obtain at least one nontrivial solution for (*) without assuming the Ambrosetti and Rabinowitz condition by using the mountain pass theorem, and obtain infinitely many high energy solutions when f(x,·) is odd by using the fountain theorem. © 2011 Elsevier Ltd. All rights reserved.

Lu J.,Liaoning Normal University | Xu L.,Korea Astronomy and Space Science Institute | Xu L.,Dalian University of Technology | Liu M.,Xinyang Normal University
Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics | Year: 2011

Kinematical models are constrained by the latest observational data from geometry-distance measurements, which include 557 type Ia supernovae (SNIa) Union2 data and 15 observational Hubble data. Considering two parameterized deceleration parameter, the values of current deceleration parameter q0, jerk parameter j0 and transition redshift zT, are obtained. Furthermore, we show the departures for two parameterized kinematical models from ΛCDM model according to the evolutions of jerk parameter j(z). Also, it is shown that the constraint on jerk parameter j(z) is weak by the current geometrical observed data. © 2011 Elsevier B.V.

Liu X.,Xinyang Normal University | Xie L.,Henan University of Technology | Li H.,Xinyang Normal University
Journal of Electroanalytical Chemistry | Year: 2012

A novel platform based on reduced graphene oxide and Au nanoparticles entrapped in chitosan/silica sol-gel hybrid membranes (RGO-AuNPs-CSHMs) was successfully constructed for the fabrication of biosensor. The hybrid membranes are prepared by cross-linking chitosan (CS) with 3-aminopropyltriethoxysilane (APTES), while the presence of RGO and AuNPs improved the conductivity of CSHMs. The morphologies and electrochemistry of the nanocomposite film were investigated by using scanning electron microscopy and electrochemical techniques including electrochemical impedance spectroscopy and cyclic voltammetry (CV), respectively. The results suggested that the modified electrode exhibited enhanced sensitivity towards the oxidation of dopamine (DA) and uric acid (UA). Well defined and separated oxidation peaks were observed by CV and differential pulse voltammetry. Linear calibration plots for the oxidation of DA and UA were obtained in the range of 1.0-200 μM for DA and 1.0-300 μM for UA. Detection limits of DA and UA were found to be 0.3-0.7 μM, respectively. In addition, the sensor was successfully applied for the determination of analytes urine samples using the standard adding method with recoveries of 94.2-106.0%. © 2012 Elsevier B.V. All rights reserved.

Kou H.,Wuhan Polytechnic University | Yang S.,Xinyang Normal University
Journal of Physical Chemistry C | Year: 2012

Band energetics of nanostructured Zn 2SnO 4 electrodes were determined with spectroelectrochemical measurements, and its trap states were investigated with electrochemistry. The flat band edges (E fb) of nanostructured Zn 2SnO 4 electrodes were highly dependent on pH of electrolyte and measured to be -0.60, -0.73, -0.85, -0.94, and -1.08 V vs saturated Ag/AgCl in 0.5 mol L -1 LiClO 4 of pH 3.0, 5.0, 6.9, 10.0, and 13.0, respectively, and followed the Nestain relationship of E fb = -0.49 - 0.046pH, V vs Ag/AgCl. The addition of acetate also changed the E fb. The E fb were measured to be -0.48, -0.54, -0.71, -0.86, and -1.03 V in 0.5 mol L -1 LiClO 4 and 1.0 mol L -1 NaAc of pH 4.0, 5.0, 7.0, 10.0, and 13.2, respectively, and followed a Nestian relationship of E fb= -0.25 - 0.060pH, V vs Ag/AgCl, very close to that reported by Wu and Alpuche-Aviles [J. Am. Chem. Soc.2009, 131, 3216]. The time-resolved currents at different applied potentials positive of flat band edge clearly indicate a trap-filling process. Trap state densities are also highly pH dependent. Total trap state densities of 2.79 × 10 15, 6.75 × 10 15, and 9.98 × 10 15 cm -2 were determined in 0.5 mol L -1 LiClO 4 solutions of pH 3.0, 6.9, and 13.0, respectively, with maximum located at -0.25 V, -0.30 V, and -0.60 V. The trap state densities of 4.17 × 10 15, 6.88 × 10 15, and 7.17 × 10 15 cm -2 were calculated in 0.5 mol L -1 LiClO 4 and 1.0 mol L -1 NaAc solutions of pH 4.0, 7.0, and 13.2, respectively. The results obtained from CVs are in good agreement with that obtained from the measurements of time-resolved currents, and the size of the peak potentials related to the trap states increases dramatically with an increase of pH, indicating that traps are mostly surface-related. © 2012 American Chemical Society.

Huang K.-J.,Xinyang Normal University | Liu Y.-J.,Xinyang Normal University | Wang H.-B.,Xinyang Normal University | Wang Y.-Y.,Xinyang Normal University | Liu Y.-M.,Xinyang Normal University
Biosensors and Bioelectronics | Year: 2014

A novel 2-dimensional graphene analog molybdenum disulfide/multi-walled carbon nanotube (MoS2/MWCNT) was synthesized by a simple hydrothermal method to achieve excellent electrochemical properties. An ultrasensitive electrochemical DNA biosensor was subsequently constructed by assembling a thiol-tagged DNA probe on a MoS2/MWCNT and gold nanoparticle (AuNP)-modified electrode that has already been coupled with glucose oxidase (GOD). In this work, GOD was used as a redox marker. The heteronanostructure formed on the biosensor surface appeared relatively good conductor for accelerating the electron transfer, while the modification of GOD and AuNPs provided multiple signal amplification for electrochemical biosensing. The multiple signal amplification strategy produced an ultrasensitive electrochemical detection of DNA down to 0.79fM with a linear range from 10fM to 107fM, and appeared high selectivity to differentiate three-base mismatched DNA and one-base mismatched DNA. The developed approach provided a simple and reliable method for DNA detection with high sensitivity and specificity, and would open new opportunities for sensitive detection of other biorecognition events. © 2013 Elsevier B.V.

Gao Y.,Xinyang Normal University
European Physical Journal D | Year: 2013

We investigate the effects of the initial correlation on the dynamics of open system in the exactly solvable pure dephasing model. We show that the role of the initial correlation come into play through a phase function and a weight factor, which would perform oscillations during time evolution, and find that the decoherence of a qubit coupled to a boson bath is more enhanced with respect to a spin bath in the short time. We also demonstrate that the trace distance between two states of a qubit can increase above its initial value, and that the initial correlation can provide another resource for the damply oscillation and revival of the entanglement of two qubits. We finally investigate the dependence of the crossover of decoherence from the dynamical enhancement to suppression under the bang-bang pulse control on the initial correlation and the statistics of the bath constituents. © 2013 EDP Sciences, SIF, Springer-Verlag Berlin Heidelberg.

Huang K.-J.,Xinyang Normal University | Wang L.,Xinyang Normal University | Li J.,Xinyang Normal University | Liu Y.-M.,Xinyang Normal University
Sensors and Actuators, B: Chemical | Year: 2013

Layered MoS2-graphene composites were synthesized by a modified l-cysteine-assisted solution-phase method, and were characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (SEM), and high-resolution transmission electron microscopy (TEM). The electrochemical properties of the nanocomposite film were investigated by electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV). Acetaminophen as model molecular was employed to study its electrochemical responses at the MoS 2-graphene modified electrode, which shows more favorable electron transfer kinetics than graphene modified glassy carbon and bare glassy carbon electrodes. This novel electrochemical sensor exhibits excellent analytical performance for acetaminophen detection with detection limit of 2.0 × 10-8 M (S/N = 3) and linear range of 0.1-100 μM. The superior electrochemical performances of MoS2-graphene composites are attributed to their robust composite structure and the synergistic effects between layered MoS2 and graphene, and it may hold great promise for electrochemical sensors and biosensors design. © 2013 Elsevier B.V.

Liu M.,Xinyang Normal University | Lu J.,Xinyang Normal University
Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics | Year: 2011

Motivated by recent logarithmic entropy of Hořava-Lifshitz gravity, we investigate Hawking radiation for Kehagias-Sfetsos black hole from tunneling perspective. After considering the effect of self-gravitation, we calculate the emission rate and entropy of quantum tunneling by using Kraus-Parikh-Wilczek method. Meanwhile, both massless and massive particles are considered in this Letter. Interestingly, two types tunneling particles have the same emission rate Γ and entropy Sb whose analytical formulae are Γ=exp[Π(rin2-rout2)/2+Π/αlnrin/rout] and Sb=A/4+Π/αln(A/4), respectively. Here, α is the Hořava-Lifshitz field parameter. The results show that the logarithmic entropy of Hořava-Lifshitz gravity could be explained well by the self-gravitation, which is totally different from other methods. The study of this semiclassical tunneling process may shed light on understanding the Hořava-Lifshitz gravity. © 2011 Elsevier B.V.

Zeng X.-L.,Xinyang Normal University | Zhang X.-L.,Xinyang Normal University | Wang Y.,Xinyang Normal University
Chemosphere | Year: 2013

The molecular geometries of 75 polychlorinated dibenzo-p-dioxins (PCDDs) were optimized using B3LYP/6-31G* method. The calculated structural parameters were taken as theoretical descriptors to establish two new novel QSPR models for n-octanol/air partition coefficients (log KOA) and subcooled liquid vapor pressure (log PL) of PCDDs. The R2 values of the two models are 0.983 and 0.985 respectively. Their standard deviations of prediction in modeling (SD) are 0.174 and 0.230 respectively. The results of leave-one-out (LOO) cross-validation for training set show that the two models exhibited optimum stability and good predictive power. © 2013 Elsevier Ltd.

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