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991.
A. M. Nobili 《Il Nuovo Cimento C》1993,16(6):789-793
Summary Any violation of the equivalence principle (EP) between test masses in the near-Earth orbit is about 500 times bigger than
on the ground, which makes the case for a space experiment very strong. Indeed, ESA and NASA (the European Space Agency and
the American National Aeronautics and Space Administration) are currently studying at Phase A level the space mission STEP,
whose main goal is to test the universality of free fall to 1 part in 1017 by means of a combination of very advanced technologies (drag free with proportional thrusters, superfluid-He temperature,
SQUID sensors). We discuss the key features of STEP as well as some novel ideas about the possibility of testing the equivalence
principle at room temperature in a non-drag-free satellite.
Paper presented at the 6th Cosmic Physics National Conference, Palermo, 3–7 November 1992. 相似文献
992.
以广义相对论为例,论述了如何根据物理理论的逻辑体系设计实验,以检验理论的正确性,对于广义相对论,检验实验应包括对等效原理的检验实验,对牛顿极限的检验实验,以及对广义相对论推论的检验实验。 相似文献
993.
M. Baiesi E. Carlon E. Orlandini A.L. Stella 《The European Physical Journal B - Condensed Matter and Complex Systems》2002,29(1):129-134
Recently Garel, Monthus and Orland [Europhys. Lett. 55, 132 (2001)] considered a model of DNA denaturation in which excluded volume effects within each strand are neglected, while
mutual avoidance is included. Using an approximate scheme they found a first order denaturation. We show that a first order
transition for this model follows from exact results for the statistics of two mutually avoiding random walks, whose reunion
exponent is c > 2, both in two and three dimensions. Analytical estimates of c due to the interactions with other denaturated loops, as well as numerical calculations, indicate that the transition is
even sharper than in models where excluded volume effects are fully incorporated. The probability distribution of distances
between homologous base pairs decays as a power law at the transition.
Received 8 July 2002 / Received in final form 25 July 2002 Published online 17 September 2002 相似文献
994.
K.J. Wiese 《The European Physical Journal B - Condensed Matter and Complex Systems》1998,1(3):273-276
The dynamical scaling properties of selfavoiding polymerized membranes with internal dimension D embedded into d dimensions are studied including hydrodynamical interactions. It is shown that the theory is renormalizable to all orders
in perturbation theory and that the dynamical scaling exponent z is given by z=d. The crossover to the region, where the membrane is crumpled swollen but the hydrodynamic interaction irrelevant is discussed.
The results apply as well to polymers (D=1) as to membranes (D=2).
Received: 5 September 1997 / Accepted: 17 November 1997 相似文献
995.
In this paper, we discuss the estimation of the number of zeros of the Abelian integral for the quadratic system which has a periodic region with a parabola and a straight line as its boundary when we perturb the system inside the class of all polynomial systems of degree n. The main result is that the upper bound for the number of zeros of the Abelian integral associated to this system is 3n-1. 相似文献
996.
Summary The detailed analysis of the behaviour of a gravitational-wave antenna coupled to a passive resonant transducer has been performed
for short bursts of gravitational radiation. An expression for the noise temperature of the system is given for the general
case of a transducer with resonant frequency and mechanical quality factor different from those of the antenna. The analysis
of the optimum noise temperature obtainable for a given system shows that the optimum performance is obtained when the frequency
of the transducer is slightly different from that of the antenna.
The main point of this paper has been presented byC. Cosmelli at theSecond Workshop on Precision Measurements on Relativistic Effects in Astrophysical Systems, held in Rome, 11–13 July 1983. 相似文献
997.
In this work, we have evaluated how well the general assisted model building with energy refinement (AMBER) force field performs in studying the dynamic properties of liquids. Diffusion coefficients (D) have been predicted for 17 solvents, five organic compounds in aqueous solutions, four proteins in aqueous solutions, and nine organic compounds in nonaqueous solutions. An efficient sampling strategy has been proposed and tested in the calculation of the diffusion coefficients of solutes in solutions. There are two major findings of this study. First of all, the diffusion coefficients of organic solutes in aqueous solution can be well predicted: the average unsigned errors and the root mean square errors are 0.137 and 0.171 × 10(-5) cm(-2) s(-1), respectively. Second, although the absolute values of D cannot be predicted, good correlations have been achieved for eight organic solvents with experimental data (R(2) = 0.784), four proteins in aqueous solutions (R(2) = 0.996), and nine organic compounds in nonaqueous solutions (R(2) = 0.834). The temperature dependent behaviors of three solvents, namely, TIP3P water, dimethyl sulfoxide, and cyclohexane have been studied. The major molecular dynamics (MD) settings, such as the sizes of simulation boxes and with/without wrapping the coordinates of MD snapshots into the primary simulation boxes have been explored. We have concluded that our sampling strategy that averaging the mean square displacement collected in multiple short-MD simulations is efficient in predicting diffusion coefficients of solutes at infinite dilution. 相似文献
998.
介绍求解二阶和三阶常系数非齐次线性微分方程的积分因子降阶方法,实例说明其应用,旨在开拓学生的解题思路,提高学生的解题能力. 相似文献
999.
We carry out an analysis of the canonical system of a minimal complex surface S of general type with irregularity q > 0.Using this analysis,we are able to sharpen in the case q > 0 the well-known Castelnuovo inequality KS2≥3pg(S) + q(S)-7.Then we turn to the study of surfaces with pg=2q-3 and no fibration onto a curve of genus > 1.We prove that for q≥6 the canonical map is birational.Combining this result with the analysis of the canonical system,we also prove the inequality:KS2≥7χ(S) + 2.This improves an e... 相似文献
1000.
The main purpose of this paper is using residue system and character sums methods to investigate the mean value properties of general k-th Gauss sums,and two exact calculating formulas are given. 相似文献