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991.
Highly efficient cascaded P-doped Raman fiber laser pumped by Nd:YVO4 solid-state laser 总被引:1,自引:0,他引:1
A highly efficient cascaded P-doped Raman fiber laser (RFL) pumped by a 1064-nm continuous wave (CW) Nd:YVO4 solid-state laser is reported. 1.15-W CW output power at 1484 nm is obtained while the input pump power is 4 W, corresponding to the power conversion efficiency of 28.8%. The threshold pump power for the second-order Stokes radiation is 1.13 W. The slope efficiency is as high as 42.6%. The experimental results are in good agreement with theoretical ones. Furthermore, the power instability of the P-doped RFL at 1484 nm in an hour is observed to be less than 5%. 相似文献
992.
Lijiang?Hu Xingwen?Zhang Yi?Sun Roberto?J.?J.?WILLIAMSEmail author 《Journal of Sol-Gel Science and Technology》2005,34(1):41-46
Instrumented-indentation testing (IIT) provided with a continuous stiffness measurement (CSM) technique was employed to measure hardness and elastic modulus profiles of thin organic/inorganic hybrid coatings on glass surfaces. Hybrids were synthesized by the hydrolytic condensation of (3-methacryloxypropyl) trimethoxysilane (MPMS) or vinyltrimethoxysilane (VMS), with 5–30 wt% tetraethoxysilane (TEOS), in the presence of formic acid. Coatings of 600–800 nm on glass substrates were obtained by dip-coating solutions of these hybrids with benzoyl peroxide (BPO) addition, and curing in an oven following a thermal cycle up to 120C. Both hardness and elastic modulus showed a maximum value close to the surface, followed by a plateau and a significant increase at higher penetrations. Hybrids based on MPMS and 20–30 wt% TEOS exhibited a good combination of intrinsic values of hardness (0.50 GPa) and brittle index (0.06–0.07), that makes them suitable for coatings of plastic substrates. 相似文献
993.
B. D. Gel’man 《Mathematical Notes》2005,78(1-2):194-203
In the present paper, we prove a fixed-point theorem for completely continuous multivalued mappings defined on a bounded convex closed subset X of the Hilbert space H which satisfies the tangential condition
, where T
X
(x) is the cone tangent to the set X at a point x. The proof of this theorem is based on the method of single-valued approximations to multivalued mappings. In this paper, we consider a simple approach for constructing single-valued approximations to multivalued mappings. This approach allows us not only to simplify the proofs of already-known theorems, but also to obtain new statements needed to prove the main theorem in this paper.__________Translated from Matematicheskie Zametki, vol. 78, no. 2, 2005, pp. 212–222.Original Russian Text Copyright © 2005 by B. D. Gel’man. 相似文献
994.
On the uniform strong approximation of Marcinkiewicz type for multivariable continuous functions 总被引:2,自引:0,他引:2
Yujun Zhang Xiaoyuan He 《分析论及其应用》2005,21(4):377-384
The rate of uniform strong approximation of Marcinkiewicz type for multivariable continuous func-tions is obtained in this paper as follows:‖1/k 1 k∑j=0|Sj(f)- f|q‖≤C/k 1 k∑j=0 Eqj(f),where Sj (f) denotes the square partial Fourier sum of f and Ej (f) denotes the square best approximation of f by trigonometric polynomials of degree (j, j, … ,j),j = 0,1, 2,…. 相似文献
995.
We present sufficient conditions on a Gaussian Mehler semigroup on a reflexive Banach space Eto be induced by a single positive symmetric operator Q \in
, and give a counterexample which shows that this representation theorem is false in every nonreflexive Banach space with a Schauder basis. We also show that the transition semigroup of a Gaussian Mehler semigroup on a separable Banach space Eacts in a pointwise continuous way, uniformly on compact subsets of E, in the space BUC(E) of bounded uniformly continuous real-valued funtions on E. The transition semigroup is shown to be strongly continuous on BUC(E) if and only if S(t) = Ifor all t 0 相似文献
996.
Daniel Wulbert 《Proceedings of the American Mathematical Society》2000,128(8):2431-2438
Let be a -finite, nonatomic, Baire measure space. Let be a finite dimensional subspace of . There is a bounded, continuous function, , defined on , such that
(1) for all , and (2) almost everywhere.
997.
HuangZhenyu 《高校应用数学学报(英文版)》2000,15(1):73-77
Abstract. Without the Lipschitz assumption and boundedness of K in arbitrary Banach spaces,the Ishikawa iteration 相似文献
998.
S. P. Sethi W. P. Drews R. G. Segers 《Journal of Optimization Theory and Applications》1982,36(1):93-109
This paper briefly reviews the literature on necessary optimality conditions for optimal control problems with state-variable inequality constraints. Then, it attempts to unify the treatment of linear optimal control problems with state-variable inequality constraints in the framework of continuous linear programming. The duality theory in this framework makes it possible to relate the adjoint variables arising in different formulations of a problem; these relationships are illustrated by the use of a simple example. This framework also allows more general problems and admits a simplex-like algorithm to solve these problems.This research was partially supported by Grant No. A4619 from the National Research Council of Canada to the first author. The first author also acknowledges the support provided by the Brookhaven National Laboratory, where he conducted his research. 相似文献
999.
1000.
D. Weipert 《Rheologica Acta》1981,20(6):605-613
Zusammenfassung In der vorliegenden Arbeit wird über die Anwendung eines Universal-Rotationsviskosimeters für Forschungszwecke in einem Getreidelaboratorium berichtet und einige dabei gewonnenen Ergebnisse diskutiert. Die Messungen wurden sowohl an niedrigviskosen Wasserextrakten und Suspensionen als auch an hochviskosen Teigen durchgeführt. Als Meßart wurden Fließ- und Viskositätskurven zur Beschreibung eines Zustandes und kontinuierliche Messungen über die Zeit und bei steigenden Temperaturen zur Erfassung der Viskositätsveränderungen durchgeführt. Mit den dabei gewonnenen Ergebnissen wird versucht, die Struktur und Beschaffenheit der Korninhaltsstoffe zu beschreiben und die Wechselwirkung dieser Merkmale und der Enzymolyse zu verdeutlichen.Schlüsselwörter Rotationsviskosimeter, Fließkurve, Viskositätskurve, kontinuierliche Viskositätsmessung, Getreidequalität
Summary In the present paper the possibilities for using a universal rotational viscometer for research purposes in cereal laboratories have been described and discussed. This kind of instrument is suitable as well for viscosity measurements in low viscous water-extracts and water-fluor slures as in high viscous doughs of such a consistency, as used in the practical breadmaking. Drawing up flow and viscosity curves for describing the condition of chemical matters in cereal grain, continuous measurements over the time at constant or defined increasing temperatures have been choosen to record the changes of the viscosity. The obtained results have been utilised to describe the structure and the state of the main constituents of cereal grains (starch, protein, pentosan) and to make evident the alternating effect between those characteristics and the enzymolysis.
Mit 11 Abbildungen 相似文献