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821.
Summary. Suppose that M is a complete, simply connected Riemannian manifold of non-positive sectional curvature with dimension m ≧ 3. If, outside a fixed compact set, the sectional curvatures are bounded above by a negative constant multiple of the inverse of the square of the geodesic distance from a fixed point and below by another negative constant multiple of the square of the geodesic distance, then the angular part of Brownian motion on M tends to a limit as time tends to infinity, and the closure of the support of the distribution of this limit is the entire S m−1 . This improves a result of Hsu and March. Received: 7 December 1994/In revised form: 2 September 1995  相似文献   
822.
在不同温度条件下利用微量热法测定了大肠杆菌以及大肠杆菌在6种Schif碱药物抑制下的生长热谱,找出了该细菌生长的最佳生长温度,获得了该细菌在不同温度条件及抑制情况下生长代谢的速率常数,并借助化学反应中分子碰撞理论计算了该细菌生长的生长活化能,在此基础上借用化学反应速率的活化络合物理论模型对大肠杆菌生长代谢的生化反应进行了热力学分析  相似文献   
823.
Applying Kontsevich's iterated integral for tangles, we get an isotopy invariant of tangles. We give a method to compute the integral of a tangle combinatorially from modified integrals of some simple tangles. We localize the integral by moving the end points of the tangle to an extreme configuration, and modify the integral so that it is convergent. By using a similar technique, we generalize Kontsevich's invariant to a framed tangle.  相似文献   
824.
Résumé Nous démontrons la conjecture de Katz concernant la méromorphie et la caractérisation des zéros et p?les unités des fonctions L associées aux représentations p-adiques lorsque celles-ci se prolongent sur une compactification du schéma de base. Comme cas particuliers importants, on obtient celui de la fonction zêta d’un schéma quelconque et celui d’une représentation p-adique quelconque sur un schéma propre.
If X is a smooth variety over a finite field ? q of characteristic p > 0 and is a p-adic sheaf associated to a representation of the fundamental group of X, N. Katz conjectures, in his Bourbaki talk 409, that the L function L (X, ℱ, t) has its p-adic unit roots and poles given in terms of p-adic étale cohomology. We prove this conjecture in the case of the structure sheaf ℱ = ℤ p , that is for the Zeta function, and also more generally when the p-adic sheaf extends to a smooth sheaf on a compactification of X: as a consequence we get the Unit-Root Zeta function of Dwork and Sperber as an L function. The idea of the proof is to get the p-adic étale cohomology with coefficients and compact support as the fixed points of Frobenius acting on rigid cohomology with compact support. For this purpose, we first build a crystalline Artin–Schreier short exact sequence on the syntomic site of a scheme which is separated of finite type over a perfect field k: this naturally generalizes the work of J.M. Fontaine and W. Messing in the proper smooth case. Then getting rigid cohomology with coefficients as a limit of crystalline cohomologies of variable level we deduce a long exact sequence connecting p-adic étale cohomology (with compact support) to rigid cohomology (with compact support). When X is smooth and affine over an algebraically closed field, the former exact sequence splits into short exact sequences that identify the p-adic étale cohomology with support of X to the part of its rigid cohomology invariant under Frobenius. We can then describe the p-adic unit roots and poles of the Zeta function of X; as a corallary we get the Unit-Root Zeta function of Dwork and Sperber as an L function. In the appendix we show that the characteristic spaces of Frobenius in rigid cohomology commute with isometric extensions of the base, and that isocrystals associated to p-adic sheaves with finite monodromy are overconvergent: we thus obtain a p-adic proof of the rationality of the corresponding L-function.


Oblatum 8-XII-1994 & 30-IV-1996  相似文献   
825.
A filtration problem with second initial-boundary value in partially saturated porous media is considered, In addition to discussion of the existence and uniqueness of weak solution of the problem, it is demonstrated that the interface between the saturated and unsaturated regions exists and continues under certain conditions and the solution possesses some properties, e.g., the balance of water content, the time-limit existence of weak solution ect. which differ from those of the solutions of the first initial-boundary value problem.  相似文献   
826.
The topological and metric properties of a few natural 2D random cellular structures, namely an armadillo shell structure and young soap froths, which are formed from two classes of cells, large and small, have been characterized. The topological properties of a model generated from a Kagome tiling, which mimics such random binary structures, have also been exactly calculated. The distribution of the number of cell sides is bimodal for the structures investigated. In contrast to the classical Aboav-Weaire law for homogeneous 2D random cellular structures, nm(n), the mean total number of edges of neighbouring cells of cells with n sides does not vary linearly with n. Only the nm(i, n) (i=1,2) determined separately for every class of cells are linear in n for all investigated structures. Topological properties and correlations between metric and topological properties are finally compared with the predictions of various literature models. Received: 24 December 1997 / Revised: 7 April 1998 / Accepted: 20 April 1998  相似文献   
827.
Using a specific version of the additive quark model we compute the relative (to proton-proton) single particle rapidity distributions for particles produced in α-α interactions at CERN ISR energies.  相似文献   
828.
This paper describes the regioselective biohydroxylation of 7-azabrendane and 6-azatwistane derivatives.  相似文献   
829.
The wavenumbers of the vibration rotation band lines of 14N16O are reported for the 2Π12-2Π12, 2Π12-2Π12 and 2Π12-2Π12 subbands of the 1-0 transition in the infrared. The full set of spectroscopic constants for this band has been determined by direct approach using the analysis of Zare, Schmeltekopf, Harrop, and Albritton. In addition to the band origin ν0 and the B, D, H constants for the lower and upper vibrational levels, the following spin-orbit coupling constants have been derived: A?0 = 123.02772 ± 0.00011 and A?1 = 122.78248 ± 0.00011 (in cm?1). Apparent centrifugal corrections to these constants have been determined and the values obtained for them are A?D0 = (0.347573 ± 0.00051) × 10?3 and A?D1 = (0.337135 ± 0.00050) × 10?3cm?1. Λ-Type doubling constants evaluated by using both grating and tunable laser data are also reported.  相似文献   
830.
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