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111.
通过对有限紧致空间中辐射场的研究来讨论腔中的原子-辐射场耦合系统. 利用T(1)×SO(4)群的表示, 给出了辐射场的单粒子波函数以及相应的色散关系. 由此详细讨论了紧致空间中辐射场的玻色-爱因斯坦统计. 发现其性质与空间的几何性质(曲率半径)有显著的依赖关系, 并表现与通常黑体辐射系统的显著差异. 相似文献
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113.
In this paper we study the atom dissipation effect in a laser cavity. The cavity field mode is described by the Fox- Li quasimode due to the leakiness of the cavity. Our results show that the atom decay rate versus the decay rate of the quasimode is a Lorentz type. Effects of the atom-cavity detuning as well as cavity size are also discussed. 相似文献
114.
It is predicted theoretically that broadening the optical confinement layer in monolithic mode-locked semiconductor lasers
may suppress Q-switching instability, by increasing the carrier transport time, and lead to emission of shorter, more stable
optical pulses. 相似文献
115.
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117.
Maurice C.G. Aalders Nine v.d. Vange Fiona A. Stewart Marloes G. Klein Mark J. v.d. Vijver Henricus J.C.M. Sterenborg 《Journal of photochemistry and photobiology. B, Biology》1999,50(2-3):88-93
This study has investigated damage to the intraperitoneal organs of the rat after systemic (intraperitoneal and intravenous) administration of low doses of 5-aminolevulinic acid (ALA) and illumination with a standard white-light operating-room (o.r.) lamp. The study has been done within the framework of a larger study in which the possibility of using ALA for localization of small-volume macroscopically nonvisible peritoneal metastasis of ovarian tumors is being investigated. Fluorescence diagnostics are done in addition to the standard staging and localization procedures, either through a laparoscope or during laparotomy. In these circumstances, fluorescence diagnostics involve some risk of photosensitization of critical organs since a broad-band (o.r.) light source is used during the surgical procedures for illumination of the operating area. The drug dose and the time interval between administration of ALA and illumination are varied and normal tissues are examined both macroscopically and microscopically for damage. A relationship is demonstrated between the maximum tolerable dose (MTD) of ALA (defined as the dose that does not cause any tissue damage) and the time interval between administration and illumination. The white light that is used for illumination of the operating area is sufficient to induce damage to the peritoneal organs at relatively low ALA doses. The MDTs for 2, 6 and 16 h intervals are found to be respectively 1, 10 and 100 mg kg−1. The results are similar for both intraperitoneal and intravenous administration. 相似文献
118.
Kazunori Nakano Kazuaki Aburaya Ichiro Hisaki Norimitsu Tohnai Mikiji Miyata 《Chemical record (New York, N.Y.)》2009,9(2):124-135
We have systematically investigated structures and properties of inclusion crystals of bile acids and their derivatives. These steroidal compounds form diverse host frameworks having zero‐, one‐ and two‐dimensional cavities, causing various inclusion behaviors towards many organic compounds. The diverse host frameworks exhibit the following guest‐dependent flexibility. First, the frameworks mainly depend on the included guests in size and shape. The size‐dependence is quantitatively estimated by the parameter PCcavity, which is the volume ratio of a guest molecule to a host cavity. The resulting values of PCcavity lie in the range of 42–76%. Second, each of the host frameworks has its own range of the values. Some guests can employ two different frameworks with the boundary values, explaining formation of polymorphic crystals. Third, the host frameworks are selected by host–guest interactions through weak hydrogen bonds, such as NH/π and CH/O. The weak hydrogen bonds play an important role for various selective inclusion processes. Fourth, the host frameworks are dynamically exchangeable, resulting in intercalation and polymerization in the cavities. These static and dynamic structures of the frameworks demonstrate great potential of crystalline organic inclusion compounds as functional materials. © 2009 The Japan Chemical Journal Forum and Wiley Periodicals, Inc. Chem Rec 9: 124–135; 2009: Published online in Wiley InterScience ( www.interscience.wiley.com ) DOI 10.1002/tcr.20171 相似文献
119.
M. L. Filshtinsky D. I. Bardzokas 《Archive of Applied Mechanics (Ingenieur Archiv)》2001,71(4-5):341-352
Summary The antiplane steady dynamic problem of the theory of elasticity for an isotropic layer and a half-layer weakened by tunnel
cavities of arbitrary cross section is investigated. A radiating monochromatic shear wave (SH-wave) is considered as loading. Using the constructed Green's functions for a layer and a half- layer, the corresponding
boundary problems are reduced to the Fredholm's integral equations of the second kind. The obtained algorithm is realized
numerically by the quadrature method. Results specifying the influence of the openings configuration, their number and relative
position, types of edge conditions and inertia effects on tangential stress concentration are given.
Received 13 July 1999; accepted for publication 20 July 2000 相似文献
120.
Optical feedback modifies the power vs. current diagram of a laser diode as well as its spectrum. Though optimization of the spectral characteristics is usually the main goal in the design of an external cavity source, power efficiency is also important, especially with relatively high power devices, where temperature variations due to dissipation can have an impact on the wavelength stability and on the laser lifetime. A useful parameter to describe the total power efficiency of the stabilized laser, relative to that of the solitary laser, is proposed in this paper. The dependence of this parameter on the characteristics of the active device, and of the external cavity, is investigated. 相似文献