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991.
Brunelle M 《The Journal of the Acoustical Society of America》2012,131(4):3088-3102
The perceptual integrality of f0, F1 and voice quality is investigated by looking at register, a phonological contrast that relies on these three properties in three dialects of Cham, an Austronesian language of Mainland Southeast Asia. The results of a Garner classification experiment confirm that the three acoustic properties integrate perceptually and that their patterns of integrality are similar in the three dialects. Moreover, they show that dialect-specific sensitivity to acoustic properties can cause salient dimensions to override weaker ones. Finally, the patterns of integrality found in Cham suggest that auditory integrality is not limited to acoustically similar properties. 相似文献
992.
We study experimentally the evaporation of an aqueous NaCl solution with efflorescence formation in hydrophilic or hydrophobic
two-dimensional model porous media. The efflorescence formation only marginally affects the invasion patterns but greatly
modifies the drying kinetics compared to pure water. Two mechanisms are identified for explaining the impact of efflorescence
formation on drying kinetics. It is shown that the efflorescence contributes to increase the evaporation rate compared to
drying with pure water, a surprising result since the water activity is reduced in the presence of dissolved salt. This effect
is explained by the efflorescence liquid capillary pumping effect associated with the porous nature of the efflorescence.
Then, we identify a second phase where the efflorescence dries out and acts as a vapour diffusion barrier, leading to a dramatic
reduction of evaporation rate. 相似文献
993.
The aim of this paper is to present a new analytical resolution to find closure equations of Wohlhart symmetric mechanism
and to give some interesting spatial properties of this mechanism. These properties are used to put in evidence possible industrial
applications for this type of mechanism. First, it concerns the analytic resolution of the twelve equations system obtained
from the closure equation, system particularized for the case of Wohlhart symmetric mechanism. The matrix form of closure
equations is written for a single loop overconstrained mechanism composed by six revolute joints, mechanisms called 6R. A
kinematical analysis is made, putting in evidence some interesting kinematical and geometrical properties. These properties
allow us to consider a new spatial disposition for this mechanism, by imposing three non-successive joints to remain in a
determined plan. Thus, we obtain a translator, a possible future industrial application for this type of overconstrained mechanism. 相似文献
994.
In this paper, a discrete element simulation scheme for pebble beds in fusion blankets is presented. Each individual pebble is considered as one element obeying equilibrium conditions under contact forces. We study not only the rearrangement of particles but also the overall behaviour of an assembly under the action of macroscopic compressive stresses. Using random close packing as initial configurations, the discrete element simulation of the uniaxial compression test has been quantitatively compared to experiments. This method yields the distribution of the inter-particle contact forces. Moreover, the micro-macro relations have been investigated to relate the microscopic information, such as the maximum contact force and the coordination number inside the assembly, to the macroscopic stress variables. 相似文献
995.
996.
We use star representation geometric methods to obtain explicit oscillatory integral formulae for strongly invariant star products on Iwasawa subgroups AN of SU(1,n) 相似文献
997.
We generalize the methods of graded contractions in order to determine, using grading arguments only, the existence of central
charges within the limit Lie algebras. As an illustration we show how this formalism allows one to recover the u(n)-bosons limits of the classical Lie algebras.
Presented by Marc de Montigny at the DI-CRM Workshop held in Prague, 18–21 June 2000. 相似文献
998.
Jean-Philippe Boisvert Marc Domenech Alain Foissy Jacques Persello Jean-Claude Mutin 《Journal of Crystal Growth》2000,220(4)
The retarding influence of sodium poly(acrylate) (PANa) on the hydration of calcium sulfate hemihydrate (CaSO4·
H2O) was investigated. This study reports the influence of sodium poly(acrylate) on hemihydrate dissolution, on homogenous and heterogeneous gypsum (CaSO4·2H2O) nucleation as well as on gypsum growth. It is shown that adsorption of PANa does not hinder the dissolution of hemihydrate in the present experimental conditions. The specific interaction of PANa with gypsum can explain the oriented growth of gypsum crystal. The gypsum growth is slowed down but cannot be blocked by the adsorption of PANa. On the other hand, PANa can block the heterogeneous and homogenous gypsum nucleation. As soon as a critical surface density of PANa onto the hemihydrate surface is reached, the heterogeneous gypsum nucleation is prevented and hemihydrate hydration is indefinitely blocked. The interaction between PANa and the hemihydrate surface is of prime importance to control hydration. Also, the influence of the molecular weight of PANa on homogenous nucleation has been investigated. The precipitation of calcium polyacrylate can explain the differences between the two molecular weights used (2100 and 20 000). This work leads to the conclusion that heterogeneous nucleation is the key process that controls hydration of a system in which hemihydrate dissolution, gypsum nucleation and growth are all occurring at the same time in a continuous manner. 相似文献
999.
We show that for a field k of characteristic p, H
i
(k,ℤ(n)) is uniquely p-divisible for i≠n (we use higher Chow groups as our definition of motivic cohomology). This implies that the natural map K
n
M
(k)?K
n
(k) from Milnor K-theory to Quillen K-theory is an isomorphism up to uniquely p-divisible groups, and that K
n
M
(k) and K
n
(k) are p-torsion free. As a consequence, one can calculate the K-theory mod p of smooth varieties over perfect fields of characteristic p in terms of cohomology of logarithmic de Rham Witt sheaves, for example K
n
(X,ℤ/p
r
)=0 for n>dimX. Another consequence is Gersten’s conjecture with finite coefficients for smooth varieties over discrete valuation rings
with residue characteristic p. As the last consequence, Bloch’s cycle complexes localized at p satisfy all Beilinson-Lichtenbaum-Milne axioms for motivic complexes, except possibly the vanishing conjecture.
Oblatum 21-I-1998 & 26-VII-1999 / Published online: 18 October 1999 相似文献
1000.
Marc A. G. T. van den Hoop Julio C. Benegas 《Colloids and surfaces. A, Physicochemical and engineering aspects》2000,170(2-3):151-160
An integrative approach based on the combined use of both experiments and modelling is discussed here aimed at investigating metal–polyelectrolyte interactions in solution. Electrochemical techniques are applied because of their potential to measure the actual speciation without disturbing the solution physico–chemical equilibrium. The experimental methodologies are complementary since the ranges of applicability depend on the solution composition itself. To complement and interpret the results of these experimental techniques, a physico–chemical association model, based on the so-called ‘chemical model’ of counterion condensation theory, is used. The model considers that, in addition to the usual electrostatic interactions and entropic effects, territorial affinity and chemical bonding interactions take place between the small counterions in solution and the polyelectrolyte. A number of particular cases of metal/polyelectrolyte systems are discussed aimed at showing that the integrative approach leads to additional information about the solution system which can not be deduced from experimental results solely. Future challenges with respect to the applications in the study of natural aquatic systems are pointed out. 相似文献