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Quantum mechanical description of waveguides  [PDF]
Zhi-Yong Wang,Cai-Dong Xiong,Bing He
Physics , 2006,
Abstract: In this paper, applying the spinor representation of the electromagnetic field, we present a quantum-mechanical description of waveguides. As an example of application, a potential qubit generated via photon tunneling is discussed.
The Problem of Conscious Observation in Quantum Mechanical Description  [PDF]
H. D. Zeh
Physics , 1999,
Abstract: Epistemological consequences of quantum nonlocality (entanglement) are discussed under the assumption of a universally valid Schr\"odinger equation in the absence of hidden variables. This leads inevitably to a {\it many-minds interpretation}. The recent foundation of quasi-classical neural states in the brain (based on environmental decoherence) permits in principle a formal description of the whole chain of measurement interactions, including the {\it behavior} of conscious observers, without introducing any intermediate classical concepts (for macroscopic "pointer states") or "observables" (for microscopic particle positions and the like) --- thus consistently formalizing Einstein's {\it ganzer langer Weg} from the observed to the observer in quantum mechanical terms.
Mechanical Proprieties of Steel at High Temperatures  [PDF]
Ana-Diana Anca?,D. Gorb?nescu
Bulletin of the Polytechnic Institute of Jassy, Constructions, Architechture Section , 2005,
Abstract: The experimental test results obtained in the study of steel mechanical proprieties variation in case of high temperatures (fire) are presented. The proprieties are referring to: Young’s modulus, E, the elastic limit, σe, and the characteristic diagram of the material (the rotation stress-strain). Theoretical laws that the model the steel behaviour at high temperature have been elaborated based on the most significant studies presented in the literature.
Synthetic description of the piano soundboard mechanical mobility  [PDF]
Kerem Ege,Xavier Boutillon
Physics , 2012,
Abstract: An expression of the piano soundboard mechanical mobility (in the direction normal to the soundboard) depending on a small number of parameters and valid up to several kHz is given in this communication. Up to 1.1 kHz, our experimental and numerical investigations confirm previous results showing that the soundboard behaves like a homogeneous plate with isotropic properties and clamped boundary conditions. Therefore, according to the Skudrzyk mean-value theorem (Skudrzyk 1980), only the mass of the structure M, the modal density n(f), and the mean loss factor eta(f), are needed to express the average driving point mobility. Moreover, the expression of the envelope - resonances and antiresonances - of the mobility can be derived, according to (Langley 1994). We measured the modal loss factor and the modal density of the soundboard of an upright piano in playing condition, in an anechoic environment. The measurements could be done up to 2.5 kHz, with a novel high-resolution modal analysis technique (see the ICA companion-paper, Ege and Boutillon (2010)). Above 1.1 kHz, the change in the observed modal density together with numerical simulations confirm Berthaut's finding that the waves in the soundboard are confined between adjacent ribs (Berthaut et al. 2003). Extending the Skudrzyk and Langley approaches, we synthesize the mechanical mobility at the bridge up to 2.5 kHz. The validity of the computation for an extended spectral domain is discussed. It is also shown that the evolution of the modal density with frequency is consistent with the rise of mobility (fall of impedance) in this frequency range and that both are due to the inter-rib effect appearing when the half-wavelength becomes equal to the rib spacing. Results match previous observations by Wogram (1980), Conklin (1996), Giordano (1998), Nakamura (1983) and could be used for numerical simulations for example. This approach avoids the detailed description of the soundboard, based on a very high number of parameters. However, it can be used to predict the changes of the driving point mobility, and possibly of the sound radiation in the treble range, resulting from structural modifications.
How to Complete the Quantum-Mechanical Description?  [PDF]
Timur F. Kamalov
Physics , 2002,
Abstract: If the statement by Einstein, Podolsky and Rosen on incompleteness of Quantum-Mechanical description of nature is correct, then we can regard Quantum Mechanics as a Method of Indirect Computation. The problem is, whether the theory is incomplete or the nature itself does not allow complete description? And if the first option is correct, how is it possible to complete the Quantum-Mechanical description? Here we try to complement de-Broglie's idea on wave-pilot the stochastic gravitation gives origin to. We assume that de-Broglie's wave-pilots are gravitational stochastic ones, and we shall regard micro-objects as test classical particles being subject to the influence of de-Broglie's waves stochastic gravitation.
Statistical mechanical description of liquid systems in electric field  [PDF]
Semjon Stepanow,Thomas Thurn-Albrecht
Physics , 2008, DOI: 10.1103/PhysRevE.79.041104
Abstract: We formulate the statistical mechanical description of liquid systems for both polarizable and polar systems in an electric field in the $\mathbf{E}$-ensemble, which is the pendant to the thermodynamic description in terms of the free energy at constant potential. The contribution of the electric field to the configurational integral $\tilde{Q}_{N}(\mathbf{E})$ in the $\mathbf{E}$-ensemble is given in an exact form as a factor in the integrand of $\tilde{Q}_{N}(\mathbf{E})$. We calculate the contribution of the electric field to the Ornstein-Zernike formula for the scattering function in the $\mathbf{E}$-ensemble. As an application we determine the field induced shift of the critical temperature for polarizable and polar liquids, and show that the shift is upward for polarizable liquids and downward for polar liquids.
Dynamic Mechanical Properties and Constitutive Relation of an Aluminized Polymer Bonded Explosive at Low Temperatures  [PDF]
Yuliang Lin,Binbin Xu,Rong Chen,Jingui Qin,Fangyun Lu
Shock and Vibration , 2014, DOI: 10.1155/2014/918103
Abstract: Polymer bonded explosives (PBXs) are widely used as energetic fillings in various warheads, which maybe are utilized under extreme environments, such as low or high temperatures. In this paper, the dynamic response of an aluminized polymer bonded explosive was tested at a range of temperatures from ?55°C to ?2°C and a fixed loading strain rate (~700?s?1) with the split Hopkinson pressure bar (SHPB). The PBX tested is aluminized, which contains 76?wt% RDX, 20?wt% aluminum powder, and 4?wt% polymer binder, respectively. The results show that the effect of temperature on the strength of the PBX is obvious at the tested strain rates. Based on the experimental results and prophase studies, a constitutive model was obtained, in which the effect of temperature and strain rate were considered. The modeling curves fit well with the experimental results, not only at low temperature under 0°C, but also at room temperature (20°C). The model may be used to predict the dynamic performances of the PBXs in various environments. 1. Introduction Due to low sensitivity and high detonation performance, the polymer bonded explosives (PBXs) are commonly used as energetic fillings in various weapon systems. In addition, the PBXs feature favorable mechanical and physical properties and can be easily shaped for different warheads. Since the operation circumstances of the weapon systems are complex, the industrial and military technology research institutions require the energetic materials to be workable under extreme environments, such as wide temperature ranges. However, PBXs’ main components are explosive crystal and polymer binder. Due to the fact that the latter can be easily affected by change in temperature, the mechanical properties of PBXs are usually nonlinear and highly temperature dependent. Further research is needed to fully characterize the dynamic mechanical properties of PBX over a wide temperature range, and the constitutive model is required to be developed to predict the dynamic mechanical properties at different temperatures. Some research works on dynamic mechanical properties of PBXs have been done [1–17]. The dynamic and static mechanical properties of PBXs were very different [5]. Furthermore, researchers have paid more attention to the effect of temperature on dynamic mechanical response of PBXs [6–16]. The stress-strain responses of PBX9501 and mock 9501 were tested under different temperatures and strain rates [6]. Gray III et al. used a specially designed SHPB setup to obtain the compression properties of PBX9501 and PBX9502 over a wide range of
Statistical-mechanical description of quantum entanglement  [PDF]
J. K. Korbicz,F. Hulpke,A. Osterloh,M. Lewenstein
Mathematics , 2007, DOI: 10.1088/1751-8113/41/37/375301
Abstract: We present a description of finite dimensional quantum entanglement, based on a study of the space of all convex decompositions of a given density matrix. On this space we construct a system of real polynomial equations describing separable states. We further study this system using statistical mechanical methods. Finally, we apply our techniques to Werner states of two qubits and obtain a sufficient criterion for separability.
A description of quasi-duo Z-graded rings  [PDF]
Andre Leroy,Jerzy Matczuk,Edmund R. Puczylowski
Mathematics , 2009,
Abstract: A description of right (left) quasi-duo Z-graded rings is given. It shows, in particular, that a strongly Z-graded ring is left quasi-duo if and only if it is right quasi-duo. This gives a partial answer to a problem posed by Dugas and Lam in [1].
Investigation of mechanical losses of thin silicon flexures at low temperatures  [PDF]
R. Nawrodt,C. Schwarz,S. Kroker,I. W. Martin,F. Brückner,L. Cunningham,V. Gro?e,A. Grib,D. Heinert,J. Hough,T. K?sebier,E. B. Kley,R. Neubert,S. Reid,S. Rowan,P. Seidel,M. Thürk,A. Tünnermann
Physics , 2010, DOI: 10.1088/0264-9381/30/11/115008
Abstract: The investigation of the mechanical loss of different silicon flexures in a temperature region from 5 to 300 K is presented. The flexures have been prepared by different fabrication techniques. A lowest mechanical loss of $3\times10^{-8}$ was observed for a 130 $\mu$m thick flexure at around 10 K. While the mechanical loss follows the thermoelastic predictions down to 50 K a difference can be observed at lower temperatures for different surface treatments. This surface loss will be limiting for all applications using silicon based oscillators at low temperatures. The extraction of a surface loss parameter using different results from our measurements and other references is presented. We focused on structures that are relevant for gravitational wave detectors. The surface loss parameter $\alpha_s$ = 0.5 pm was obtained. This reveals that the surface loss of silicon is significantly lower than the surface loss of fused silica.
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