时分复用倍乘光脉冲重复率的新型光纤耦合器环状连接法分析

提出并详细分析了一种基于时分复用技术倍乘光脉冲重复率的方法：在２×２光纤耦合器的一个输入口与一个输出口间，接入时延为脉冲列半周期奇数倍的一段光纤使之形成环状连接循环耦合，而在另一输出口获得光脉冲。详细分析了该系统中光纤耦合器耦合比、插入损耗、时延光纤长度的要求，偏差的影响及其调节法，给出了理论公式、结果的计算机模拟与实验介绍；与经典的马赫陈德尔干涉仪接法及近年提出的Ｓａｇｎａｃ环接法进行了比较。该方法特别适用于对窄脉冲列进行串接复用实现重复率的多次倍乘，从而得到数千兆赫至上百千兆赫的高重复率光脉冲     

Gamma-rays from Mössbauer sources: a low-dose approach to cancer therapy

Summary A new approach to cancer treatment using low-energy gamma-rays is discussed. Cultures of bone marrow mononuclear cells collected from normal donors and patients with chronic myelogenous leukaemia have been studied after the addition of hematin, at different concentrations, and irradiation by a M?ssbauer gamma-ray source. Growth stimulation has been observed when hematin is added to normal bone marrow cultures, while growth inhibition is observed when hematin is added to leukaemic cultures. The effect becomes then more pronounced when hematin is used in combination with M?ssbauer gamma-rays.     

水闸闸室结构三维样条边界元分析

用三维样边界元法分析水闸闸室结构。底板，闸墩和载水墙等为其子结构，交通桥，工作桥和胸墙等处理为内部支撑。地基和边载可以是任意的，只要能给定地表位移面力关系。在各种工况下，不论是设置平板门还是弧形门，是平底板是反拱底板，即使在稀疏剖分下也能给出高精度的位移场，应力场和地基反力场。     

基于变芯径光纤的光学系统在光造型中的应用

光学系统采用变芯径光纤，可大幅度提高光的传输效率，增加光学子系统柔性。描述了光造型工作原理及其理论依据，在介绍所研制的光的成型系统光学子系统的基础上，阐述了紫外光源的选择与设计，及变芯径光纤的设计、传输、耦合与聚焦等技术。该套基于变芯径光纤的光学子系统成本低、体积小、效率高，巳成功应用于所研制的台式低成本快速成型系统中，为该系统的进一步推广奠定了技术基础。     

On the index of composition of integers from various sets

Given an integer n ≥ 2, let λ(n) := (log n)/(log γ(n)), where γ(n) = Π _p|n p, stand for the index of composition of n, with λ(1) = 1. We study the distribution function of (λ(n) – 1) log n as n runs through particular sets of integers, such as the shifted primes, the values of a given irreducible cubic polynomial and the shifted powerful numbers. Research supported in part by a grant from NSERC. Research supported by the Applied Number Theory Research Group of the Hungarian Academy of Science and by a grant from OTKA. Professor M.V. Subbarao passed away on February 15, 2006. Received: 3 March 2006 Revised: 28 October 2006     

Blackett Memorial Lecture: the nuclear option—human factors in safety

The UK nuclear industry is currently undergoing a series of dramatic changes. Important, among many is the establishment of the Nuclear Decommissioning Authority (NDA) with an associated impact on service delivery. At the same time, the debate on the future of our energy supply in the UK is increasingly focused on the question of the nuclear option. Issues of safety and reliability are paramount for the nuclear industry given both the nature of the hazard and the associated public perceptions of the associated risks. This paper explores linked developments in human factors and the management of safety in the nuclear industry in the context of unprecedented change.     

Temperature sensors and optical sensors

The dependence of temperature on the fluorescence lifetime and fluorescence intensity ratio using Stark sublevels and thermally coupled (close lying) levels in triply ionized rare earth ions, doped into a variety of glasses and fibers, have been reviewed. Also, it is claimed that not only for the two closely lying levels of triply ionized rare earth ion of the same kind, but also for two different triply ionized rare earth ions, having their excited levels very close to each other, may be used to monitor the temperature. PACS 42.70.Ce     

Discontinuity in decision-making when objectives conflict: a military command decision case study

In previous work, we considered the representation of human decision-making processes in closed-form simulation models of conflict. An important element of this representation is the rapid planning process that embodies the processing of information for situation assessment to support a course of action decision (eg in a military headquarters). The application of this work is in support of operational analysis models for defence procurement and balance of investment. This paper describes the application of non-linear multi-attribute utility theory in conflict scenarios in order to extend the representation of the rapid planning process to account for a wider set of subjective attributes of the decision-maker. The results show, through examination of experimental data, that decision-making can be modelled through a particular class of utility functions. These utilities embody a geometry which allows us to classify the types of decision being made when there are conflicting objectives and when decision-makers adopt very different and subjective appraisals of constraints and beliefs in outcome. The experimental results help to demonstrate that the subjective nature of the situation assessment, and the personality, training, experience and history of the decision-maker are central to the functional representations. This paper presents a way to capture this deeper representation of human decision-making in a way that is potentially useful for quantitative modelling using the rapid planning process as a basis.     

Thin strain-relaxed SiGe grown by ultrahigh vacuum chemical vapor deposition

Large-scale preparation of thin strain-relaxed SiGe is achieved by combining ion implantation and ultrahigh vacuum chemical vapor deposition. The resulting materials were analyzed by double crystal X-ray diffraction, micro-Raman spectroscopy, and tapping mode atomic force microscope. Results revealed that 100-nm-thick Si_0.7Ge_0.3 layers with the diameter of 125 mm and full strain relaxation are successfully prepared by pre-modifying the Si substrates using 50 keV Ar⁺ ions. The strain relaxation is also disclosed to change with both ion species and energy. However, post-modification of SiGe by ion implantation will cause serious damage to the crystal structures, and result in the formation of poly-crystal SiGe.