Nonlinear static characteristics of piezoelectric unimorph bending micro actuators

The nonlinear static characteristic of a piezoelectric unimorph cantilever micro actuator driven by a strong applied electric field is studied based on the couple stress theory.The cantilever actuator consists of a piezoelectric layer,a passive（elastic）layer and two electrode layers.First,the nonlinear static characteristic of the actuator caused by the electrostriction of the piezoelectric layer under a strong applied electric field is analyzed using the Rayleigh-Ritz method.Secondly,since the thickness of the cantilever beam is in micro scale and there exists a size effect,the size dependence of the deformation behavior is evaluated using the couple stress theory.The results show that the nonlinearities of the beam deflection increase along with the increase of the applied electric field which means that softening of the micro beam rigidity exists when a strong external electric field is applied.Meanwhile,the optimal value of the thickness ratio for the passive layer and the piezoelectric layer is not around 1.0 which is usually adopted by some previous researchers.Since there exists a size effect of the micro beam deflection,the optimal value of this thickness ratio should be greater than 1.0 in micro scale.

Otolith shape analysis for stock discrimination of two Collichthys genus croaker(Pieces:Sciaenidae,)from the northern Chinese coast

The otolith morphology of two croaker species(C ollichthys lucidus and C ollichthys niveatus) from three areas(Liaodong Bay, LD; Huanghe(Yellow) River estuary, HRE; Jiaozhou Bay, JZ) along the northern Chinese coast were investigated for species identifi cation and stock discrimination. The otolith contour shape described by elliptic Fourier coefficients(EFC) were analysed using principal components analysis(PCA) and stepwise canonical discriminant analysis(CDA) to identify species and stocks. The two species were well dif ferentiated, with an overall classifi cation success rate of 97.8%. And variations in the otolith shapes were significant enough to discriminate among the three geographical samples of C. lucidus(67.7%) or C. niveatus(65.2%). Relatively high mis-assignment occurred between the geographically adjacent LD and HRE samples, which implied that individual mixing may exist between the two samples. This study yielded information complementary to that derived from genetic studies and provided information for assessing the stock structure of C. lucidus and C. niveatus in the Bohai Sea and the Yellow Sea.

A FRACTAL MODEL AND ENERGY DISSIPATION FOR EN ECHELON FRACTURES

observations from the field and the taboratory show that en echelon fractures withinfracture zones have a foede1 within Ricdel structure’ The tensile fallure mecbanism of en echelonfractures can be described by the pile-ups of sbear crack-dislocations. A fractal model can be used tosimulate the Riedel within Xiedel geometry, allowing the direct rneasarement of tbe ftactal dimen sions of en echelon fractare systems. The energy dissipation of tbe en ccbe1on fracture system canbe deduced using a fracil damage evo1ution model which exptalns tbe evo1ution process of en eche lon fracture svstems. The fractal nature of the fractures can be used to dcrive an accurate estimateof total energy dissipation.

Potential Energy Surface in Hartree-Fock Theory： Adiabatic orConfiguration-Constrained？

Validity of adiabatic assumption is discussed within the constrained Hartree-Fock theory for self-conjugate nucleus ~(72)Kr.It is shown that the adiabatic assumption does not provide a correct description for the nature of nucleus when a configuration change is involved.The excited Hartree-Fock states and the continuously-connected constrained Hartree-Fock states are given for the first time by applying the configuration dictated constrained Hartree-Fock theory with Gogny force.The importance of self-consistency between the mean-field and the single particle wave functions is emphasized even when a small number of nucleons are involved in the configuration change.

Physical modeling of failure process of the excavation in horizontal strata based on IR thermography

In order to capture the mechanism of roadway instability in deep mines, a new approach of Physically Finite Elemental Slab Assemblage (PFESA) is proposed in order to construct a large-scale physical model simulating the geologically horizontal strata. We carried out physical modeling on the deformation and failure processes of roadways subjected to a plane loading scheme. Our laboratory tests were based on work which incorporated infrared (IR) detection, IR radiation temperature (IRT) statistics, image feature extraction and 2D Fourier transformation, from resulting thermographies. The IRT characterizes the mechanical responses from the roadway after loading with two stages, i.e., IRT evolving at higher levels corresponded to shallow mining (≤500 m) during which the roadway deformed gradually (referred to as the "steady deformation stage"); IRT evolving in a quasi-cyclical manner with multiple peaks corresponded to deep mining (800–2600 m), in which the failure mode for the roadway are dominated by breakage and collapse (called the "unsteady deformation stage"). The IR images and 2D Fourier spectra illustrate detailed information in terms of initiation, nucleation and coalescence of the damage to rock masses and the eventual failure of roadways subject to external loading.

Anharmonic Vibrational Signatures of DNA Bases and Watson-Crick Base Pairs

Changes of molecular structure and associated charge distributions, and changes of anharmonic vibrational parameters from DNA base monomers to the Watson-Crick base pairs, have been investigated at the density functional theory level. Through examination of the NH2, N H, and C=O stretching vibrational modes that are involved in the multiple H-bonds in the base pairs, sensitivity of their diagonal and off-diagonal anharmonicities, as well as anharmonic vibrational couplings, to the structure change are predicted. Our results reveal the intrinsic connection between the anharmonic vibrational potentials, H-bonding, and electrostatic interactions in DNA bases.

Phronesis and Transformative Learning： A Joint Challenge for Moral Philosophy and Educational Theory

Strengthening moral learning may become available to us by bringing phronesis and transformative learning in a common theoretical space. For both Aristotle and Mezirow, the exercise of morality, or rising to the standard of moral choice, decision, and action, is not the result of an intuitive achievement or a sudden understanding of a morally demanding situation but a lifelong affair. Our strategy here addresses three aims： Firstly, to invoke and reclaim the endemic bond between education in the broader sense of paideia and the significant role that reeds to be re-ascribed to moral education. This allows a turn towards qualitative features and makes room for an inclusion of moral education, or values education, within education. Secondly, to portray the exercise of autonomy, choice, and judgment as a result of paideutic development; both theories share the assumption that moral learning rests on constant reflection upon past experiences and the zetesis of future goals. Thirdly, to focus on the way one reclaims the right to exercise judgment, whenever this is required. A joint study of the two theories may enlighten the content of this lifelong reflective procedure.

Death of a Salesman, When Tragedy Meets the Modern Man

The most persistent criticism about the play Death of a Salesman （1949） concerns the issue of genre and its constituents： Is it a tragedy？! If yes, to what extend is it a tragedy？ Miller himself considered the play to be the tragedy of the common man, as he presents his idea on tragedy as a genre and his idea of the tragic hero in his essay ＂Tragedy and the Common Man＂ （1942）, but for a group of critics it is not a tragedy but to others and to the author, it is the tragedy of the man who tries to survive in the modern world by using archaic weapons. This paper briefly revisits the Aristotelian tragedy concept and modern theories, and stands on what are tragedy and a tragic hero. It aims at reading Death of a Salesman as a meeting point between （ancient） concept of tragedy with modern man and his way of seeing life, and briefly examines and explores the continuing disagreements among academics and by what criteria this play is a tragedy.

Theoretical analysis of the relationship between the Brillouin gain coefficient and the strain in the optical-fiber sensors

The relation between the power of the Brillouin signal and the strain is one of the bases of the distributed fiber sensors of temperature and strain. The coefficient of the Bfillouin gain can be changed by the temperature and the strain that will affect the power of the Brillouin scattering. The relation between the change of the Brillouin gain coefficient and the strain is thought to be linear by many researchers. However, it is not always linear based on the theoretical analysis and numerical simulation. Therefore, errors will be caused if the relation between the change of the Brillouin gain coefficient and the strain is regarded as to be linear approximately for measuring the temperature and the strain. For this reason, the influence of the parameters on the Brillouin gain coefficient is proposed through theoretical analysis and numerical simulation.

An Annotation of Language Teacher Beliefs in View of Educational Culture

The research on foreign language （FL） teachers＇ cognition and its development has been attracting attention in the field of applied linguistics. However, the gap between teaching theories and truths, teacher beliefs and behaviors can only be annotated by an in-depth investigation of belief determinants （BD） that are shaped by specific educational culture. Based on an investigation of language teacher beliefs, this paper is an annotation of language teacher beliefs in view of educational culture. By using both qualitative and quantitative methods of interviewing forefront teachers and making a literature review, it intends to reveal the dynamic nature of teacher beliefs as the teaching reality in view of the impact and significance of educational culture. It hammers home with the conclusion that the teachers-role-fulfillment in China is based on their real beliefs and loaded with cultural, social, and subject pressure; it is not a lincal impartment from theory to practice, from advocating to implementing, but a selective practice with teachers＇ active cognition and adaptation towards the local educational culture.

Semiclassical Calculation of Recurrence Spectra of Rydberg Hydrogen Atom Near a Metal Surface

Using closed orbit theory, we give a clear physical picture description of the Rydberg hydrogen atom near a metal surface and calculate the Fourier transformed recurrence spectra of this system at different scaled energies below ionization threshold. The results show that with the increase of the scaled energy, the number of the closed orbit increases greatly. Some of the orbits are created by the bifurcation of the perpendicular orbit. This case is quite similar to the Rydberg atom in an electric field. When the scaled energy increases furthermore, chaotic orbits appear. This study provides a different perspective on the dynamical behavior of the Rydberg atom near a metal surface.

从肺论治法和从肠论治法对溃疡性结肠炎大鼠肺与结肠VEGF-A蛋白及mRNA的影响

目的:观察从肺论治法和从肠论治法对溃疡性结肠炎(UC)大鼠肺与结肠血管内皮细胞生长因子-A(VEGF-A)含量的影响。方法:采用家兔结肠黏膜组织致敏与三硝基苯磺酸-乙醇模型相结合的免疫复合法复制UC大鼠模型。从造模成功的40只大鼠及正常组大鼠中随机选出8只作为干预前(0周时间点)的模型组及正常组。剩余造模成功的32只大鼠随机分为模型组、西药组(柳氮磺胺吡啶)、黄芪桔梗汤组、黄芪黄连汤组,每组8只,另取8只正常大鼠为正常组,连续干预4周后,分别于0、4周时间点采用Western blot和Real time-PCR法测定肺与结肠组织VEGF-A蛋白及mRNA表达。结果:0周模型组大鼠肺和结肠组织中VEGF-A mRNA与正常组无差异,肺和结肠组织VEGF-A蛋白表达较正常组显著升高(P<0.05)。4周模型组大鼠肺组织中VEGF-A mRNA和蛋白表达与正常组比较,显著升高(P<0.01),西药组和黄芪黄连汤组肺组织中VEGF-A mRNA和蛋白表达较之模型组显著下调(P<0.01,P<0.05);模型组和西药组大鼠结肠组织中VEGF-A mRNA及蛋白表达与正常组相比,显著升高(P<0.01),黄芪桔梗汤组、黄芪黄连汤组VEGF-A mRNA及蛋白表达较模型组和西药组显著下调(P<0.05,P<0.01)。结论:微血管内皮是启动及维持炎症的一种重要细胞成分,UC肺损伤的机制可能与异常的血管生成有关,从肺论治法和从肠论治法均能通过下调UC肺及结肠组织中过度表达的VEGF-A,减轻肺及结肠组织的炎性损伤。

Analysis of Heat Transfer Phenomenon in Magnetohydrodynamic Casson Fluid Flow Through Cattaneo–Christov Heat Diffusion Theory

Heat transport phenomenon of two-dimensional magnetohydrodynamie Casson fluid flow by employing Cattaneo-Christov heat diffusion theory is described in this work. The term of heat absorption/generation is incorporated in the mathematical modeling of present flow problem. The governing mathematical expressions are solved for velocity and temperature profiles using RKF 45 method along with shooting technique. The importance of arising nonlinear quantities namely velocity, temperature, skin-friction and temperature gradient are elaborated via plots. It is explored that the Casson parameter retarded the liquid velocity while it enhances the fluid temperature. Fhrther, we noted that temperature and thickness of temperature boundary layer are weaker in case of Cattaneo-Christov heat diffusion model when matched with the profiles obtained for Fourier＇s theory of heat flux.

R-mode Instability of Neutron Star with Non-Newtonian Gravity

The Chandrasekhar-Friedmann-Schutz （CFS） instabilities of r-modes for canonical neutron stars （1.4 Me） with rigid crusts are investigated by using an equation of state of asymmetric nuclear matter with super-soft symmetry energy, where the non-Newtonian gravity proposed in the grand unification theories is also considered. Constrained by the observations of the masses and the spin frequencies for neutron stars, the boundary of the r-mode instability window for a canonical neutron star is obtained, and the results show that the observed neutron stars are all outside the instability window, which is consistent with the theoretical expectation. In addition, an upper limit of the non-Newtonian gravity parameters is also given.

Maximal B-Regular Integro-Differential Equation

By using Fourier multiplier theorems, the maximal B-regularity of ordinary integro-differential operator equations is investigated. It is shown that the corresponding differential operator is positive and satisfies coercive estimate. Moreover, these results are used to establish maximal regularity for infinite systems of integro-differential equations.