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71.
Yu. S. Barash A. G. Grishin M. Sigrist 《Journal of Experimental and Theoretical Physics》1997,85(1):168-172
The effect of the moment of a magnetic impurity on the order parameter of an unconventional superconductor is examined. The
coupling of the magnetic moment to the order parameter induces a locally time-reversal symmetry-breaking state which generates
a magnetic field distribution in the vicinity of the impurity. The magnetic field can cause precession of the magnetic moment.
The case of a spin polarized muon injected into the superconductor is discussed.
Zh. éksp. Teor. Fiz. 112, 304–312 (July 1997)
Published in English in the original Russian journal. Reproduced here with stylistic changes by the Translation Editor. 相似文献
72.
2 laser photoacoustic spectrometer has been developed for the in-situ monitoring of atmospheric trace gases in different environments.
Numerous air pollutants, such as ammonia, ethene, ozone and alcohols, can be monitored with a time resolution of a few minutes.
A new fitting algorithm based on the numerical method of Levenberg–Marquardt is discussed and applied to the derivation of
individual gas concentrations from measured photoacoustic signal amplitudes and phases at selected CO2 laser wavelengths. The algorithm has been tested with artificially generated multicomponent gas mixtures exhibiting gas concentrations
in the ppb to ppm range. Furthermore, its potential is demonstrated with the analysis of an air sample from a fruit storage
chamber and with ambient air measurements during a field study in a rural environment.
Received: 23 March 1998/Revised version: 18 June 1998 相似文献
73.
Dr. Jan Dreiser Kasper S. Pedersen Dr. Alexander Schnegg Dr. Karsten Holldack Joscha Nehrkorn Marc Sigrist Dr. Hannu Mutka Dr. Høgni Weihe Dr. Vladimir S. Mironov Prof. Jesper Bendix Prof. Oliver Waldmann 《Chemistry (Weinheim an der Bergstrasse, Germany)》2013,19(11):3693-3701
We have investigated the single‐molecule magnets [MnIII2(5‐Brsalen)2(MeOH)2MIII(CN)6]NEt4 (M=Os ( 1 ) and Ru ( 2 ); 5‐Brsalen=N,N′‐ethylenebis(5‐bromosalicylidene)iminate) by frequency‐domain Fourier‐transform terahertz electron paramagnetic resonance (THz‐EPR), inelastic neutron scattering, and superconducting quantum interference device (SQUID) magnetometry. The combination of all three techniques allows for the unambiguous experimental determination of the three‐axis anisotropic magnetic exchange coupling between MnIII and RuIII or OsIII ions, respectively. Analysis by means of a spin‐Hamiltonian parameterization yields excellent agreement with all experimental data. Furthermore, analytical calculations show that the observed exchange anisotropy is due to the bent geometry encountered in both 1 and 2 , whereas a linear geometry would lead to an Ising‐type exchange coupling. 相似文献
74.
The feasibility of laser-photoacoustic measurements for the detection and the analysis of different isolated doping agents in the vapour phase is discussed. To the best of our knowledge, this is the first time that photoacoustic vapour-phase measurements of doping substances have been presented. Spectra of different doping classes (stimulants, anabolica, diuretica, and beta blockers) are shown and discussed in terms of their detection sensitivity and selectivity. The potential of laser spectroscopy for detecting the intake of prohibited substances by athletes is explored. PACS 07.57.Ty; 33.20.Ea; 82.80.Kq 相似文献
75.
P. A. Frigeri D. F. Agterberg I. Milat M. Sigrist 《The European Physical Journal B - Condensed Matter and Complex Systems》2006,54(4):435-448
In materials without an inversion center of symmetry the spin
degeneracy of the conducting band is lifted by an antisymmetric
spin orbit coupling (ASOC). Under such circumstances, spin and
parity cannot be separately used to classify the Cooper pairing
states. Consequently, the superconducting order parameter is
generally a mixture of spin singlet and triplet pairing states. In
this paper we investigate the structure of the order parameter and
its response to disorder for the most symmetric pairing state
(A1). Using the example of the heavy Fermion superconductor
CePt3Si, we determine characteristic properties of the
superconducting instability. Depending on the type of the
pairing interaction, the gap function is characterized
by the presence of line nodes. We show that this line nodes move in general
upon temperature.
Such nodes would be essential to explain recent low-temperature
data of thermodynamic quantities such as the NMR-T1
-1,
London penetration depth, and heat conductance.
Moreover, we study the effect of (non-magnetic) impurity on the superconducting state. 相似文献
76.
C. Leblond J.F. Sigrist B. Auvity H. Peerhossaini 《Journal of Fluids and Structures》2009,25(1):134-154
This paper deals with the transient motions experienced by an elastic circular cylinder in a cylindrical fluid domain initially at rest and subjected to small-amplitude imposed displacements. Three fluid models are considered, namely potential, viscous and acoustic, to cover different fluid–structure interaction regimes. They are derived here from the general compressible Navier–Stokes equations by a formal perturbation method so as to underline their links and ranges of validity a priori. The resulting fluid models are linear owing to the small-amplitude-displacement hypothesis. For simplicity, the elastic flexure beam model is chosen for the circular cylinder dynamics. The semi-analytical approach used here is based on the methods of Laplace transform in time, in vacuo eigenvector expansion with time-dependent coefficients for the transverse beam displacement and separation of variables for the fluid. Moreover, the viscous case is handled with a matched asymptotic expansion performed at first order. The projection of the fluid forces on the in vacuo eigenvectors leads to a fully coupled system involving the modal time-dependent displacement coefficients. These coefficients are then obtained by matrix inversion in the Laplace domain and fast numerical inversion of the Laplace transform. The three models, written in the form of convolution products, are described through the analysis of their kernels, involving both the wave propagation phenomena in the fluid domain and the beam elasticity. Last, the three models are illustrated for a specific imposed motion mimicking shock loading. It is shown that their combination permits coverage of a broad range of motions. 相似文献
77.
A simple, economic diode laser based cavity ringdown system for trace-gas applications in the petrochemical industry is presented. As acetylene (C2H2) is sometimes present as an interfering contaminant in the gas flow of ethylene (ethene, C2H4) in a polyethylene production process, an on-line monitoring of such traces is essential. We investigated C2H2–C2H4 mixtures in a gas-flow configuration in real time. The experimental setup consists of a near-infrared external cavity diode laser with an output power of a few mW, standard telecommunication fibers and a home-made gas cell providing a user-friendly cavity alignment. A noise-equivalent detection sensitivity of 4.5×10-8 cm-1 Hz-1/2 was achieved, corresponding to a detection limit of 20 ppbV C2H2 in synthetic air at 100 mbar. In an actual C2H2–C2H4 gas-flow measurement the minimum detectable concentration of C2H2 added to the C2H4 gas stream (which may already contain an unknown C2H2 contamination) increased to 160 ppbV. Moreover, stepwise C2H2 concentration increments of 500 ppbV were resolved with a 1-min time resolution and an excellent linear relationship between the absorption coefficient and the concentration was found. PACS 07.07.Df; 42.62.Fi; 82.80.Gk 相似文献
78.
79.
High resolution spectral data of 100 ppmV (10(-6) per volume) concentrations of the trace gases bromo methane (BM, CH3Br), and methyl bromide (DME, (CH3)2O), buffered in synthetic air (80% N2, 20% O2) at atmospheric pressure and room temperature are reported. The spectra are recorded with a continuously tunable 10-bar CO2 laser based photoacoustic (PA) spectrometer. The tuning range covers 76 cm(-1) between 9.2 microm (1087 cm(-1)) and 10.7 microm (935 cm(-1)) at a constant narrow line-width of 0.018 cm(-1) (540 MHz). The non-resonant PA measuring cell employs an in-line 10-microphone array. The estimated detection limits for BM and DME are approximately 2 ppmV for a signal-to-noise ratio (SNR) of 3. This corresponds to a calculated detection limit of approximately 76 ppbV for ethylene. 相似文献
80.
Novel aspects of the excimer laser etching of nanostructures in embedded optical fibers are discussed. Emphasis is put on the etching of a specified hole geometry and on excellent surface quality of the hole walls.On leave from: Institute of Quantum Electronics, ETH, CH-8093 Zürich, Switzerland 相似文献