Optical bistability via tunable Fano-type interference in asymmetric semiconductor quantum wells

We analyze hybrid absorptive-dispersive optical bistability (OB) behavior via tunable Fano-type interference based on intersubband transitions in asymmetric double quantum wells (QWs) driven coherently by a probe laser field by means of a unidirectional ring cavity. We show that OB can be controlled efficiently by tuning the energy splitting of the two excited states (the coupling strength of the tunnelling), the Fano-type interference, and the frequency detuning. The influence of the electronic cooperation parameter on the OB behavior is also discussed. This investigation may be used for optimizing and controlling the optical switching process in the QW solid-state system, which is much more practical than that in atomic system because of its flexible design and the controllable interference strength.     

Light Amplification in a New Light Transducer Combining an Organic Electroluminescent Diode with Photoresponsive Organic Pigment Film

Light amplification was successfully demonstrated in an all-organic light transducer based on hybridization of an organic electroluminescent diode and a perylene pigment film as an electron photoinjecting electrode. Amplification gain of photon conversion from red to red light reached 25 with the assistance of effective electron photoinjection due to large photocurrent multiplication in a perylene film. Optical switching behavior caused by feedback of output-light to the photoconductive layer was observed.     

Controlling the bugs

In late 1984, the Reagan administration proposed a Coordinated Framework for Regulation of Biotechnology. Its proposed regulatory approach appears less constraining than the deep concerns of the 1970s concerning the risk of biotechnology would have suggested. Several distinctive characteristics of the early period of biotechnology, particularly the role of the research community in developing the initial regulatory system and the extent of federal funding, explain this development. The administration’s proposal may attract substantial support. However, implementation may lead to conflicts and problems, especially concerning human germ-line gene therapy and environmental release of viable genetically engineered organisms.     

Optimal stock liquidation in a regime switching model with finite time horizon

This paper is concerned with a finite-horizon optimal selling rule. A set of geometric Brownian motions coupled by a finite-state Markov chain is used to characterize stock price movements. Given a fixed transaction fee, the optimal selling rule can be obtained by solving an optimal stopping problem. The corresponding value function is shown to be the unique viscosity solution to the associated HJB equations. Numerical solutions to these equations and their convergence are obtained. A numerical example is presented to illustrate the results.     

三值 BiCMOS电路

本文在分析二值 BiCMOS 电路及“开关信号理论”的基础上, 用开关级设计方法提出了新的三值 BiCMOS 电路. 与 CMOS 三值电路相比,新的电路的驱动能力明显要强得多, 因而在大电容负载条件下有更 好的速度性能.     

高分子凝胶电解质及其在电色Smart窗中的应用

研究了高分子凝胶电解质高氯酸锂－碳酸丙烯酯－聚甲基丙烯酸甲酯体系（ＬｉＣｌＯ４－ＰＣ－ＰＭＭＡ）的离子导电性、导电机理以及在电色Ｓｍａｒｔ窗中的应用．其离子电导率与温度的关系服从Ｖｏｇｅｌ－Ｔａｍｍａｎｎ－Ｆｕｌｃｈｅｒ方程，并与体系的ＰＭＭＡ质量百分数、玻璃化温度（Ｔｇ）、碱金属盐的浓度等有关．当ＬｉＣｌＯ４浓度为０．５ｍｏｌ／Ｌ，ＰＭＭＡ＝３５％时，电解质具有良好的粘附性、光学透明度及较高的室温离子电导率（σ＝８．７５×１０－４Ｓ／ｃｍ）．由其组装成的全固态电色Ｓｍａｒｔ窗具有良好的光谱特性，可见光调制范围为４０％～６０％；具有良好的光开关特性，响应时间仅为５ｓ．     

Rapidly tunable all-optical wavelength converter based on single semiconductor optical amplifier delay interferometer

We demonstrate a rapidly tunable 10 Gb/s all-optical wavelength converter based on a semiconductor optical amplifier delay interferometer and a tunable laser. It uses a 16-channel 100 GHz-spacing digitally tunable multifrequency laser based on a novel external-cavity laser design. The bit sequence on the incoming wavelength is converted alternatively to different wavelengths. Power penalties are 1.1 dB for 30 ns guard-time spacing between wavelength packets.     

数字合成技术在三相信号源中的应用

介绍数字合成技术在三相精密功率信号源中成功地应用。该信号源中采用硬件数字合成的办法产生三相电压与三相电流信号正弦波。文中详细介绍数字合成电路的组成与工作原理。     

R－（Cu，Ni）二元和三元体系相图及相形成规律

根据Ｒ－（Ｃｕ，Ｎｉ）二元和三元体系的相图及其所存在的金属化合物，探讨了这些体系的相形成规律。     

An algorithm for network dimensioning under reliability considerations

In this paper we introduce a new methodology to adjust link capacities in circuit switched networks taking into account the costing policy and reliability considerations. This methodology, which is an extension of previous work on reliability evaluation using routing models, is based on a cyclic decomposition algorithm which alternates between a routing subproblem and a link capacity adjustment subproblem. The proposed procedure, which is shown to converge to a global optimum for the dimensioning/routing problem, has been tested on a 14 undirected arc problem for various levels of link failure probability. The numerical results are extremely satisfactory and they demonstrate the usefulness of the proposed method for proper network dimensioning.