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921.
M. A. Macrì C. Del Gratta L. Di Donato S. Di Luzio G. L. Romani S. Della Penna A. Pasquarelli 《Il Nuovo Cimento D》1994,16(5):425-432
Summary A preliminary study is here reported on a new potential marker for biomagnetic measurements. The marker consists of superparamagnetic
polymer microspheres which were detected in the presence of external steady magnetic fields by means of an r.f.-SQUID magnetometer.
The particles were prepared in samples differing in the concentration value and immersed in a homogeneous magnetic field of
variable intensity. A simple model was taken into account for the distribution of the microspheres in the samples, so that
the theoretical values were compared to the marker field values measured by the biomagnetic sensor. The overall sensitivity
of the experimental apparatus and the minimum concentration value of the marker were then estimated. 相似文献
922.
Shu-Cheng Chang 《Mathematische Annalen》2002,324(3):465-490
In this paper, we consider the 2-dimensional local Calabi flow on a complete noncompact surface . Then, based on the Harnack-type estimate, we show the long-time existence and asymptotic convergence of a subsequence of
solutions of such a flow on with and bounded from above by a negative constant on a ball. For its applications, this will lead to the existence of extremal metrics
on a complete noncompact surface of finite topological type. In particular, there exists an extremal metric of nonconstant
Gaussian curvature on or
Received: 21 June 2001 / 18 January 2002 / Published online: 27 June 2002
Research supported in part by NSC and NCTS. 相似文献
923.
The He1 photoelectron (PE) spectra of both 2(5H) furanone and itstrans-chair-dimeric-compound (t-c-DFN) are reported. The assignment of the PES bands is made on the basis of band shapes, the PES results of the molecules
which have the similar atomic groups, and the restricted Hartree-Fock (RHF) calculations for the molecules studied. From the
results of both PES experimental and theoretical calculations, it is proved that the ionization potential (IPS) of the HOMO
for the dimeric-compound is lower than that of the HOMO for the monomer. And the total energy computed for thet-c-DFN is the lowest in the four possible configurations of dimeric-compounds of 2(5H) furanone. Therefore the synthesis oft-c-DFN is also the easiest.
Project supported by the National Natural Science Foundation of China. 相似文献
924.
V. Formisano G. Bellucci A. Grigoriev A. Coradini J. P. Bibring 《Il Nuovo Cimento C》1992,15(6):1113-1119
Summary Multispectral imaging of planets opens a new class of studies of atmospheric and surface signatures. With ISM experiment on
board Phobos, the first IR multispectral imaging of Mars from space was achieved. In viem of the Future Omega experiment on
board Mars 94, we present here a sample of data and results (and problems) which can be achieved by studying spectral reflectance.
Paper presented at the V Cosmic Physics National Conference, S. Miniato, November 27–30, 1990. 相似文献
925.
Analogues of the well-known Kolosov–Muskhelishvili formulas of general representations are obtained for nonhomogeneous equations of statics in the case of the theory of elastic mixtures. It is shown that in this theory the displacement and stress vector components, as well as the stress tensor components, are represented through four arbitrary analytic functions.The usual Cauchy–Riemann conditions are generalized for homogeneous equations of statics in the theory of elastic mixtures. 相似文献
926.
Summary. In this paper we are interested in two phase flow problems in porous media. We use a Dual Mesh Method to discretize this
problem with finite volume schemes. In a simplified case (elliptic - hyperbolic system) we prove the convergence of approximate
solutions to the exact solutions. We use the Dual Mesh Method in physically complex problems (heterogeneous cases with non
constant total mobility). We validate numerically the Dual Mesh Method on practical examples by computing error estimates
for different test-cases.
Received March 21, 1997 / Revised version received October 13, 1997 相似文献
927.
一类非经典扩散方程整体解的存在唯一性及长时间行为 总被引:5,自引:0,他引:5
本文讨论非经典扩散方程第一初边值问题整体解的存在唯一性及长时间行为,建立了一系列新的结果,较好地改进许多已有的结论. 相似文献
928.
929.
Non-Markovian Brownian motion in a periodic potential is studied by means of an electronic analogue simulator. Velocity spectra, the Fourier transforms of velocity autocorrelation functions, are obtained for three types of random force, that is, a white noise, an Ornstein—Uhlenbeck process, and a quasimonochromatic noise. The analogue results are in good agreement both with theoretical ones calculated with the use of a matrix-continued-fraction method, and with the results of digital simulations. An unexpected extra peak in the velocity spectrum is observed for Ornstein-Uhlenbeck noise with large correlation time. The peak is attributed to a slow oscillatory motion of the Brownian particle as it moves back and forth over several lattice spaces. Its relationship to an approximate Langevin equation is discussed. 相似文献
930.
多目标分数变分问题的对偶性 总被引:1,自引:0,他引:1
本文利用参数逼近在函数广义(F,ρ)-凸的条件下,建立了一类多目标式变分问题关于有效解的对偶理论。 相似文献