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961.
B. Deva Prasad Raju K.V. Narasimhulu J. Lakshmana Rao 《Journal of Physics and Chemistry of Solids》2005,66(5):753-761
X-band electron paramagnetic resonance (EPR) studies on divalent copper ions embedded in KMgClSO4·3H2O single crystals have been performed at low temperature (123 K). The angular variation of the EPR spectra reveals the presence of two Cu2+ sites, which have different orientations. The spin-Hamiltonian parameters of this six-coordinated cupric ion have been evaluated from the EPR spectra at 123 K. The forbidden lines due to ΔmI=±1 transitions are observed in between allowed transitions. The temperature variation EPR studies have also been performed both for a single crystal and a polycrystalline sample. The ground state wavefunction of Cu2+ ions has been estimated and is found to be an admixture of d3z2−r2 and dx2−y2. The temperature variation of the EPR spectra reveals that Cu2+ ions exhibit dynamic Jahn-Teller effect. From the polycrystalline EPR data, the temperature dependent magnetic susceptibilities are evaluated and discussed. 相似文献
962.
Kuang Yu-ping 《Frontiers of Physics in China》2006,1(1):19-37
We review the developments of the multipole expansion approach in quantum chromodynamics and its applications to hadronic
transitions and some radiative decays of heavy quarkonia. Theoretical predictions are compared with updated experimental results. 相似文献
963.
S. Djordjevic E. Farber G. Deutscher N. Bontemps O. Durand J.P. Contour 《The European Physical Journal B - Condensed Matter and Complex Systems》2002,25(4):407-416
We report results obtained with two different experimental set-ups in state-of-the-art YBCO thin films as similar as possible,
prepared by pulsed laser deposition on LaAlO3 substrates: a surface impedance measurement on 4000 ? thick films using a parallel plate resonator (10 GHz), and a far infrared
transmission (100-400 GHz) measurement which requires thinner (1000 ?) samples. The former measurement yields the temperature
variation of the penetration depth λ(T) and the real part of the conductivity, provided the absolute value of λ(T) is known. The latter yields the imaginary part of the conductivity, hence the absolute value of the penetration depth, as
well as its temperature dependence at the measuring frequency. Combining these two experiments, we establish a quasi-linear
temperature variation of λ(T), with a 2 ? K-1 low temperature slope, and a fairly large zero temperature value λ(T = 0)=(1800±200) ? . The scattering rate of the quasi-particles calculated from a two-fluids model shows that the films compare
to good quality single crystals, where twice a larger slope has been found. This surprising behavior is described in detail,
including an in-depth structural analysis of the samples in order to evaluate their similarities. We find that the 10 GHz
data obtained in the thickest films can be fitted to the dirty d-wave mode in the unitarity limit, with an extrapolated slope of 3 ? K-1, but yield a scattering rate that is difficult to reconcile with the high T
c (92 K) of the films.
Received 7 May 2001 and Received in final form 18 October 2001 相似文献
964.
1 Introduction Alongperiodfibergrating (LPFG)isanovelpassivefiberelementarisinginrecentyears[1] .SeveralapplicationsofLPFGhavebeenfound ,suchas gain profileflattenedfilter,band rejectionfilter,andtemperature ,strainornewchemicalsensors[2 ,3] .ItcanbeUV writtenor… 相似文献
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柱层析色谱分离性能优良的新型塑料脱模剂,纯化后得一主要未知组分。用元素分析、红外光谱、核磁共振氢谱研究其结构特征,对其盐酸酸化前后红外光谱吸收峰及核磁带进行了归属分析并确定结构。结果表明,该组分为一表面活性剂N,N-二羟乙基十二烷基胺。这为新型脱模剂的产品开发提供了依据。 相似文献
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