Asymptotic analysis of a vibrating cantilever with a nonlinear boundary

Nonlinear vibration of a cantilever in a contact atomic force microscope is analyzed via an asymptotic approach. The asymptotic solution is sought for a beam equation with a nonlinear boundary condition. The steady-state responses are determined in primary resonance and subharmonic resonance. The relations between the response amplitudes and the excitation frequencies and amplitudes are derived from the solvability condition. Multivaluedness occurs in the relations as a consequence of the nonlinearity. The stability of steady-state responses is analyzed by use of the Lyapunov linearized stability theory. The stability analysis predicts the jumping phenomenon for certain parameters. The curves of the response amplitudes changing with the excitation frequencies are numerically compared with those obtained via the method of multiple scales. The calculation results demonstrate that the two methods predict the same varying tendencies while there are small quantitative differences. Supported by the National Outstanding Young Scientists Fund of China (Grant No. 10725209), the Shanghai Leading Academic Discipline Project (Grant No. S30106), and Shandong Jiaotong University Science Foundation (Grant No. Z200812) Recommended by LIAO ShiJun     

Deceleration of a continuous-wave （CW） molecular beam with a single quasi-CW semi-Gaussian laser beam

We propose a promising scheme to decelerate a CW molecular beam by using a red-detuned quasi-cw semi-Gaussian laser beam （SGB）. We study the dynamical process of the deceleration for a CW deuterated ammonia （ND3） molecular beam by Monte-Carlo simulation method. Our study shows that we can obtain a ND3 molecular beam with a relative average kinetic energy loss of about 10% and a relative output molecular number of more than 90% by using a single quasi-cw SGB with a power of 1.5kW and a maximum optical well depth of 7.33mK.     

Optimal controlled teleportation via several kinds of three-qubit states

The probability of successful controlled teleportation of an unknown qubit using a general three-particle state is investigated. The analytic expressions of maximal probabilities via several kinds of tripartite states are given, including a tripartite Greenberger-Horne-Zeilinger state and a tripartite W-state. Supported by the National Natural Science Foundation of China (Grant No. 10671054), the Key Project of Science and Technology Research of Ministry of Education of China (Grant No. 207011), and the Natural Science Foundation of Hebei Province, China (Grant No. 07M006)     

The double reflection on the interface of uniaxial crystals in the Savart polariscope

The reflection in the Savart polariscope is different from the isotropic medium. The double reflection of rays in the Savart polariscope is analyzed and discussed on the basis of the Snell law. The double reflection formulae of the extraordinary ray and the ordinary ray are given. These results may provide a theoretical and practical guide for studying, developing and engineering polarization interference imaging spectrometers. Supported by the National Natural Science Foundation of China (Grant Nos. 40375010 and 60278019), the Science and Technology Plan Foundation of Shaanxi Province (Grant No. 2005K04-G18), and the Special Research Project of Shaanxi Provincial Educational Department (Grant No. 07JK261)     

Galerkin method for steady-state response of nonlinear forced vibration of axially moving beams at supercritical speeds

The present paper investigates the steady-state periodic response of an axially moving viscoelastic beam in the supercritical speed range. The straight equilibrium configuration bifurcates in multiple equilibrium positions in the supercritical regime. It is assumed that the excitation of the forced vibration is spatially uniform and temporally harmonic. Under the quasi-static stretch assumption, a nonlinear integro-partial-differential equation governs the transverse motion of the axially moving beam. The equation is cast in the standard form of continuous gyroscopic systems via introducing a coordinate transform for non-trivial equilibrium configuration. For a beam constituted by the Kelvin model, the primary resonance is analyzed via the Galerkin method under the simply supported boundary conditions. Based on the Galerkin truncation, the finite difference schemes are developed to verify the results via the method of multiple scales. Numerical simulations demonstrate that the steady-state periodic responses exist in the transverse vibration and a resonance with a softening-type behavior occurs if the external load frequency approaches the linear natural frequency in the supercritical regime. The effects of the viscoelastic damping, external excitation amplitude, and nonlinearity on the steady-state response amplitude for the first mode are illustrated.     

Quantum secret sharing between multiparty and multiparty with four states

A protocol of quantum secret sharing between multiparty and multiparty with four states was presented. It was shown that this protocol can nullify the Trojan horse attack with a multi-photon signal, the fake-signal attack with Einstein-Podolsky-Rosen pairs, the attack with single photons, and the attack with invisible photons. In addition, the upper bounds of the average success probabilities were given for dishonest agent eavesdropping encryption using the fake-signal attack with any two-particle entangled states. Supported by the National Natural Science Foundation of China (Grant No. 10671054), the Key Project of Science and Technology Research of Education Ministry of China (Grant No. 207011) and the Natural Science Foundation of Hebei Province, China (Grant Nos. A2005000140 and 07M006)     

On optics of human meridians

A new concept and its methodology for studying human meridians are presented based on rigorous and scientific observation on the objective existence of human meridians in view of biomedical optics. According to this methodology, the infrared radiant characteristics of acupuncture meridians over human body and the optical transport properties of light propagating along the meridian are reported. This study, thus, confirms the existence of acupuncture meridians, sheds new light on an approach to investigation of human meridians and offers a new perspective in understanding the potential meridian functions such as energy and information transfer and physiological regulation. Supported by the National Key Basic Research Program of China (Grant No. 2006CB504505), the National Natural Science Foundation of China (Grant Nos. 60578056 and 30572309), the Science Research Foundation of Ministry of Health & United Fujian Provincial Health and Education Project for Tackling the Key Research of China (Grant No. WKJ2005-2-004), the Young Scientists and Technicians Innovation Project of Fujian Province (Grant No. 2007F3026), and the Fund from Fujian Normal University (Grant No. 2008100218)     

Bang-bang control suppression of amplitude damping in a three-level atom

By using quantum bang-bang control technique, we studied the suppression of amplitude damping, or energy dissipation, in a three-level atom in various configurations. We have explicitly given the bang-bang control groups in three different configurations, and the pulse sequences for these bang-bang control operations. Supported by the National Natural Science Foundation of China (Grant No. 10547003), the Key Project of Chinese Ministry of Education (Grant No. 306020) and Chifeng College Scientific Research Fund (Grant No. ZRZD200604)     

Exact Analytical Solution to Equations of Perihelion Advance in General Relativity

Previously the perihelion advance in binary system was computed approximately. We will present an exact analytical solution to nonlinear differential equation of perihelion advance by method of Jacobian elliptic function and the advanced angle between successive perihelions. Project supported by the Scientific Research Foundation for the Returned Overseas Chinese Scholars from Ministry of Education, China (Grant No. [2004]527) and the Natural Science Foundation of Hunan Province, China (Grant No. 06JJ2026)     

Uniformly valid solutions of the coupling turning-point problem in revolution shell vibration

The turning-point problem in free vibration of revolution shells has the coupling property between the bending and membrane solutions. The uniformly valid solutions for this coupling turning-point problem are obtained based on three categories of generalized functions. Furthermore, they are verified to be uniformly valid in the low, turning-point and high frequency ranges. The obtained solutions exhibit a symmetric coupling structure between the bending and membrane solutions. Supported by the Natural Science Foundation of Zhejiang Province of China (Grant No. 100039) and the Shanghai Leading Academic Discipline Project (Grant No. S30106)     

Solution of a mixed parity nonlinear oscillator: Harmonic balance

The method of harmonic balance is used to calculate first-order approximations to the periodic solutions of a mixed parity nonlinear oscillator. First, the amplitude in the negative direction is expressed in terms of the amplitude in the positive direction. Then the two auxiliary equations, where the restoring force functions are odd, are solved by using a first harmonic term (without a constant). Therefore, we obtain the two approximate solutions to the mixed parity nonlinear oscillator. One is expressed in terms of the exact amplitude in the negative direction, the other in terms of the approximate amplitude. These solutions are more accurate than the second approximate solution obtained by the Lindstedt–Poincaré method for large amplitudes.     

Extraction of optical constants and thickness of nanometre scale TiO2 film

TiOTiO2 薄膜 沉积物 磁电管喷射系统 X射线 发射光谱TiO₂ thin films, pointwise constrained optimization approach, constrained nonlinear programming, optical constants, parameters extractionProject supported by Shanghai Municipal Commission for Science and Technology (Grant No 03DZ14025) and National Basic Research Program of China (Grant No 2006CB300406).3/4/2005 12:00:00 AM2005-03-042005-07-28TiO2 thin films were deposited on glass substrates by sputtering in a conventional rf magnetron sputtering system. X-ray diffraction pattern and transmission spectrum were measured. The curves of refraction index and extinction coefficient distributions as well as the thickness of films calculated from transmission spectrum were obtained. The optimization problem was also solved using a method based on a constrained nonlinear programming algorithm.     

Study on time-resolved fluorescence dynamics of cyanine dye sensitizing AgBr

The fluorescence spectra of three different dyes adsorbed on the tabular and cubic AgBr microcrystals are obtained by the picosecond time-resolved streak camera technique. The dependence of the ultrafast electron transferring from dye-aggregates to the conduction band of AgBr and the efficiency of spectral sensitization on different kinds of dyes with different concentrations is analyzed. Further more, the microcosmic mechanism of the sensitization process is discussed. It is found that the fluorescence decay curves are fitted very well by the double exponential function, consisting of a slow component and a fast one with large amplitude. We consider this fast one mainly attributable to the electron transfer from dye J-aggregates to the conduction band of AgBr. Supported by the National Natural Science Foundation of China (Grant No. 60478033), the Doctoral Foundation of Hebei Province of China (Grant No. B2003119), and the Science and Technology Project of Hebei Province of China (Grant No. 05215102)     

Quantum secret sharing between <Emphasis Type="Italic">m</Emphasis>-party and <Emphasis Type="Italic">n</Emphasis>-party with six states

A quantum secret sharing scheme between an m-party group and an n-party group is proposed using three conjugate bases. A sequence of single photons, each of which is prepared in one of the six states, is used directly to encode classical information in the quantum secret sharing process. In this scheme, each of all m members in group 1 chooses randomly his/her own secret key individually and independently, and directly encodes his/her respective secret information on the states of single photons via unitary operations, then the last one sends 1/n of the resulting qubits to each member of group 2. By measuring their respective qubits, all members in group 2 share the secret information shared by all members in group 1. It renders impossible a Trojan horse attack with a multi-photon signal, a fake-signal attack with EPR pairs, an attack with single photons, and an attack with invisible photons. We give the upper bounds on the average success probabilities for dishonest agent eavesdropping encryption using the fake-signal attack with any two-particle entangled states. Supported by the National Natural Science Foundation of China (Grant No. 10671054), the Key Project of Science and Technology Research of Education Ministry of China (Grant No. 207011) and the Natural Science Foundation of Hebei Province, China (Grant Nos. 07M006 and F2009000311)     

Approximate homotopy symmetry method: Homotopy series solutions to the sixth-order Boussinesq equation

An approximate homotopy symmetry method for nonlinear problems is proposed and applied to the sixth-order Boussinesq equation,which arises from fluid dynamics.We summarize the general formulas for similarity reduction solutions and similarity reduction equations of different orders,educing the related homotopy series solutions.Zero-order similarity reduction equations are equivalent to the Painlevé IV type equation or Weierstrass elliptic equation.Higher order similarity solutions can be obtained by solving...     

Enhanced mechanical behaviour of lead zirconate titanate piezoelectric composites incorporating zinc oxide nanowhiskers

This paper reports that the lead zirconate titanate （PZT） piezoelectric composites incorporating zinc oxide nanowhiskers （ZnOw） were prepared by the conventional solid state processing. The whisker-dispersed PZT composites （PZT/ZnOw） presented a significant enhancement in the mechanical properties such as Young＇s modulus, tensile strength and compressive strength. Especially, the compressive strength increased from 153 MPa for the PZT to 228 MPa for the PZT/ZnOw composites. The reinforcement mechanism in strength of the composites was discussed. The me- chanical quality factors of the PZT/ZnOw composites increased considerably, while the piezoelectric constants and electromechanical coupling coefficient decreased slightly. The composites with good electrical and excellent mechanical properties are promising for further applications.     

Self-organization effect in poly（3-hexylthiophene）： methanofullerenes solar cells

This paper studies the self-organization of the polymer in solar cells based on poly（3-hexylthiophene）： [6, 6]-phenyl C61-butyric acid methyl ester by controlling the growth rate of active layer. These blend films are characterized by UV-vis absorption spectroscopy, charge-transport dark J - V curve, x-ray diffraction pattern curve, and atomic force microscopy. The results indicate that slowing down the drying process of the wet films leads to an enhanced selforganization, which causes an increased hole transport. Increased incident light absorption, higher carrier mobility, and balanced carrier transport in the active layer explain the enhancement in the device performance, the power conversion efficiency of 3.43% and fill factor up to 64.6% are achieved under Air Mass 1.5, 100 mW/cm^2.     

First-principles calculations on the electronic structure and optical properties of BaSi<Subscript>2</Subscript>

The electronic structure, densities of states and optical properties of the stable orthorhombic BaSi₂ have been calculated using the first-principle density function theory and pseudopotential method. The results show that BaSi₂ is an indirect semiconductor with the band gap of 1.086 eV, the valence bands of BaSi₂ are mainly composed of Si 3p, 3s and Ba 5d, and the conduction bands are mainly composed of Ba 6s, 5d as well as Si 3p. The static dielectric function ɛ ₁(0) is 11.17, the reflectivity n ₀ is 3.35, and the biggest peak of the absorption coefficient is 2.15×10₅ cm⁻¹. Supported by the National Natural Science Foundation of China (Grant Nos. 60566001 and 60766002), the Specialized Research Fund for the Doctoral Program of Higher Education of China (Grant No. 20050657003), the Scientific Research Foundation for the Returned Overseas Chinese Scholars, Ministry of Education of China (Grant No. (2005)383), the Specialized Fund of Nomarch for Excellent Talent of Science and Technology of Guizhou Province (Grant No. Z053114), the Scientific and Technological Projects for the Returned Overseas of Guizhou Province (Grant No. (2004)03), and the Top Talent’s Scientific Research Project of Organization Department of Guizhou Province (Grant No. Z053123)     

分数阶时滞反馈对Duffing振子动力学特性的影响

研究了含分数阶时滞耦合反馈的Duffing自治系统, 通过平均法得到了系统周期解的一阶近似解析形式, 定义了以反馈系数、分数阶阶次、时滞参数表示的等效刚度和等效阻尼系数, 发现分数阶时滞耦合反馈同时具有速度时滞反馈和位移时滞反馈的作用. 比较了三种参数条件下近似解析解与数值积分的结果, 二者的吻合精度都很高, 证明了近似解析解的正确性和准确性. 分析了反馈系数、分数阶阶次和非线性刚度系数等参数对系统分岔点、周期解稳定性、周期解的存在范围、零解的稳定性以及稳定性切换次数等系统动力学特性的影响.     

Tunneling spectra of underdoped Bi_2Sr_2Ca_(1-x)Y_xCu_2O_(8+δ) intrinsic Josephson junctions

<正>Mesa-structured submicron intrinsic Josephson junctions are successfully fabricated and well characterized on underdoped Bi_2Sr_2Ca_(1-x)Y_xCu-2O_(8+δ) single crystals with a T_c of 80 K.Tunneling spectra at the temperatures ranging from 4.2 K to 295 K are measured.A pulse technique is used to reduce sample heating for the measurement near pseudogap opening temperature T~*~280 K.Our experimental results show that the superconducting gap,the peak-dip separation,and the pseudogap opening temperature are all increased as compared with those from near optimally doped samples,which requires further theoretical analysis in the future.