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31.
G. L. Bourdet R. A. Muller G. M. Mullot J. Y. Vinet 《Applied physics. B, Lasers and optics》1987,44(2):107-110
In this paper, we report on a new concept for active mode locking of lasers. It has been successfully applied to a cw waveguide CO2 laser and pulse widths as short as 2 ns have been obtained. 相似文献
32.
Delmas T Couffin AC Bayle PA de Crécy F Neumann E Vinet F Bardet M Bibette J Texier I 《Journal of colloid and interface science》2011,360(2):471-481
Lipid nanoparticles (LNP) have been designed based on low cost and human-use approved excipients, and manufactured by an easy, robust, and up-scalable process. Fluid colloidal dispersions or gel viscous formulations of highly stable nanoparticles (more than 12 month stability is achieved for some formulations) can be obtained. Their physicochemical properties are studied by Dynamic Light Scattering, Differential Scanning Calorimetry, and NMR. The results picture nanoparticles with a non-crystalline core, which viscosity can be finely tuned by the lipid composition and the temperature. A design of experiments has been used to investigate the limits of the system colloidal stability. The impact of core and surfactant weight fractions have been explored both experimentally and using the design of experiments. The versatility of this physicochemical system could open the way to a wide range of future pharmaceutical applications. 相似文献
33.
Glycoproteins in animal cells contain a variety of glycan structures that are added co‐ and/or posttranslationally to proteins. Of over 20 different types of sugar–amino acid linkages known, the two major types are N‐glycans (Asn‐linked) and O‐glycans (Ser/Thr‐linked). An abnormal mucin‐type O‐glycan whose expression is associated with cancer and several human disorders is the Tn antigen. It has a relatively simple structure composed of N‐acetyl‐D ‐galactosamine with a glycosidic α linkage to serine/threonine residues in glycoproteins (GalNAcα1‐O‐Ser/Thr), and was one of the first glycoconjugates to be chemically synthesized. The Tn antigen is normally modified by a specific galactosyltransferase (T‐synthase) in the Golgi apparatus of cells. Expression of active T‐synthase is uniquely dependent on the molecular chaperone Cosmc, which is encoded by a gene on the X chromosome. Expression of the Tn antigen can arise as a consequence of mutations in the genes for T‐synthase or Cosmc, or genes affecting other steps of O‐glycosylation pathways. Because of the association of the Tn antigen with disease, there is much interest in the development of Tn‐based vaccines and other therapeutic approaches based on Tn expression. 相似文献
34.
M. Pierre M. Hofheinz X. Jehl M. Sanquer G. Molas M. Vinet S. Deleonibus 《The European Physical Journal B - Condensed Matter and Complex Systems》2009,70(4):475-481
We extend a simple model of a charge trap coupled to a single-electron box to energy ranges and parameters such that it gives
new insights and predictions readily observable in many experimental systems. We show that a single background charge is enough
to give lines of differential conductance in the stability diagram of the quantum dot, even within undistorted Coulomb diamonds.
It also suppresses the current near degeneracy of the impurity charge, and yields negative differential lines far from this
degeneracy. We compare this picture to two other accepted explanations for lines in diamonds, based respectively on the excitation
spectrum of a quantum dot and on fluctuations of the density-of-states in the contacts. In order to discriminate between these
models, we emphasize the specific features related to environmental charge traps. Finally we show that our model accounts
very well for all the anomalous features observed in silicon nanowire quantum dots. 相似文献
35.
It is shown how symmetries of Dirac equations can be used to obtain constants of motion for nonrelativistic supersymmetric quantum Hamiltonians. In particular, conserved supercharges are found for a spin-1/2 particle in the field of a dyon which yield under anticommutation the generalized Runge-Lenz symmetry of the system.This work is supported in part through funds provided by the Natural Sciences and Engineering Research Council (NSERC) of Canada and the Fonds FCAR of the Quebec Ministry of Education. 相似文献
36.
We provide a braid group action on theq-deformed Weyl algebraW
q
(n). The restriction of this action to the representations ofU
q
(A
n–1
) andU
q
(C
n
) inW
q
(n) is seen to agree with the braid group action introduced by Lusztig on these quantum algebras.Supported in part by the National Sciences and Engineering Research Council (NSERC) of Canada. 相似文献
37.
The superspace formulation for the dynamical supersymmetry of the Pauli system in the presence of a Dirac magnetic monopole is presented. It is used to prove that Osp(1, 1) is the largest dynamical invariance group of this system. The action of finite transformations on the parameters of superspace and on the supervariables is given. 相似文献
38.
A theory of cw injection phase locking in homogeneously broadened media is investigated using density matrix formalism to derive the interactions of three coherent fields with a two levels system. This powerful formalism leads to analytical expressions of the complex gain for each wave propagating inside the amplifier medium. Studies of the minimum signal intensity for single-frequency operation and power output are related. 相似文献
39.
40.