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61.
Torbjörn Kolsrud 《Journal of Theoretical Probability》1989,2(4):399-418
We derive explicit isomorphism formulas between weighted Dirichlet integrals for harmonic functions and boundary Dirichlet forms. Applications yield results on traces of Markov processes and convergence quasieverywhere of harmonic functions. 相似文献
62.
Uwe Bandelow Mindaugas Radziunas Andrei Vladimirov Bernd Hüttl Ronald Kaiser 《Optical and Quantum Electronics》2006,38(4-6):495-512
We study both theoretically and experimentally typical operation regimes of 40 GHz monolithic mode-locked lasers. The underlying
Traveling Wave Equation model reveals quantitative agreement for characteristics of the fundamental mode-locking as pulse
width and repetition frequency tuning, as well as qualitative agreement with the experiments for other dynamic regimes. Especially
the appearance of stable harmonic mode-locking at 80 GHz has been predicted theoretically and confirmed by measurements. Furthermore,
we derive and apply a simplified Delay-Differential-Equation model which guides us to a qualitative analysis of bifurcations
responsible for the appearance and the breakup of different mode-locking regimes. Higher harmonics of mode-locking are predicted
by this model as well. 相似文献
63.
Atsushi Kasue 《Potential Analysis》2006,24(2):137-194
We study spectral convergence of compact Riemannian manifolds or more generally certain Dirichlet spaces, obtaining some compactness
results on harmonic functions and harmonic maps.
Mathematics Subject Classifications (2000) 53C21, 58D17, 58J50.
Atsushi Kasue: Partly supported by the Grant-in-Aid for Scientific Research (B) No. 15340053 of the Japan Society for the
Promotion of Science. 相似文献
64.
激光对生物分子的共振激发作用 总被引:7,自引:0,他引:7
在生物分子的“谐”和“非谐”振子势模型的基础上,用量子力学讨论了激光对生物分子的共振激作用;并用之对激光的生物激活、诱变机理的“共振吸收”定性理论作一解析分析。 相似文献
65.
The basic principle of comparing the sample
mass with the mass of a reference body in equilibrium gives the equal-armed
beam balance a unique accuracy. Main parameters characterising the suitability
of the instrument are measuring range, resolution and relative sensitivity
(resolution/maximum load). The historical development of the values of these
parameters achieved depended strongly on the practical need in those times.
Technically unfavourable scales of the oldest Egyptian dynasties (~3000
BC) could resolve mass differences of 1 g and had a relative sensitivity of
at least 10–3. More sophisticated instruments
from the 18th Dynasty (~1567–1320 BC) achieved
a relative sensitivity of 10–4 independent
of the size of the instrument. In 350 BC Aristotle clarified the theory of
the lever and at about 250 BC Archimedes used the balance for density determinations
of solids. The masterpiece of a hydrological balance was Al Chazini’s
'Balance of Wisdom’ built about 1120. Its relative sensitivity
was 2⋅10–5.
Real progress took
place when scientists like Lavoisier (1743–1794) founded modern chemistry.
At the end of the 19th century metrological balances
reached a relative sensitivity of 10–9 with
a maximum load of several kilogrammes. That seems to be the high end of sensitivity
of the classical mechanical beam balance with knife edges. Improvements took
place by electrodynamic compensation (Emich, Gast).
In 1909 Ehrenhaft
and Millikan could weigh particles of 10–15
g by means of electrostatic suspension. In 1957 Sauerbrey invented the oscillating
quartz crystal balance. By observing the frequency shift of oscillating carbon
nanotubes or of silica nanorods, masses or mass changes in the attogram or
zeptogram have been observed recently. 相似文献
66.
Jean Bricmont Joel L. Lebowitz Christian Maes 《Journal of statistical physics》1987,48(5-6):1249-1268
We derive a number of new results for correlated nearest neighbor site percolation onZ
d. We show in particular that in three dimensions the strongly correlated massless harmonic crystal, i.e., the Gaussian random field with mean zero and covariance –, has a nontrivial percolation behavior: sites on whichS
x
h percolate if and only ifh
c
. with0
c
< . This provides the first rigorous example of a percolation transition in a system with infinite susceptibility. 相似文献
67.
Artem Malakho Marc Dussauze Bogdan Lazoryak Frederic Adamietz 《Journal of solid state chemistry》2005,178(6):1888-1897
Crystallization of glasses with compositions (1−x)(0.95 NaPO3+0.05 Na2B4O7)+xNb2O5, x=0.4, 0.43, 0.45, 0.48 was investigated by differential scanning calorimetry and X-ray powder diffraction. Crystallization of two phases was observed in the glasses with x=0.43-0.48. First phase is a sodium niobate with the structure of tetragonal tungsten bronze () and second phase is Na4Nb8P4O32 (). The crystallization of sodium niobate is correlated with increasing of nonlinear optical efficiency reported for thermally poled glasses with x>0.4. The results of Raman spectroscopy show the formation of three-dimensional (3D) niobium oxide framework in the glasses with increase of niobium concentration. This framework is supposed to have tetragonal tungsten bronze structure and to be responsible for nonlinear optical properties of the glass. Second harmonic generation signals of as prepared and crystallized glass after thermal poling are compared. The nucleation and crystallization do not improve the NLO properties of the glasses under study. 相似文献
68.
采用Hartree-Fock和MP2方法在多种水平下优化了(H2O)^+n(n =1,2)的几何结构,并进行了振动光谱分析。结果表明:对(H2O)^+采用MP2/6-311++G(d,p)可得出最满意的结论。 相似文献
69.
E. Robens 《Journal of Thermal Analysis and Calorimetry》1996,47(2):619-622
A survey is given on important standardized definitions by which the capability of balances may be characterized. Some modifications are proposed with regard to the use of mass sensors for the continuous determination of mass variations. An important supplement is the relative resolution introduced by Jenemann. Optimum values are presented.I am indepted to H. R. Jenemann for his critical remarks. 相似文献
70.