b→ssd decay in Randall-Sundrum models

The extremely small branching ratio of the b → ssd decay in the Standard Model makes it a suitable channel to explore new-physics signals.We study this ?S = 2 process in Randall-Sundrum models,including the custodially protected and the bulk-Higgs Randall-Sundrum models.Exploring the experimentally favored parameter spaces of these models suggests a possible enhancement of the decay rate,compared to the Standard Model result,by at most two orders of magnitude.     

光信息科学与技术专业实践教学的探索

在四年办学经验的基础上,探索了适合地方经济建设的光信息科学与技术的本科专业的实践教学体系,进一步提升了办学水平。     

光信息科学与技术专业的教学改革——双语教学

分析了光信息科学与技术专业的特点,探讨了该专业双语教学改革的特点和提高双语教学效果的方法,为专业发展提出了思路。     

三代微光和超二代微光夜视技术的研究和开发

介绍三代微光和超二代微光夜视技术的发展概况：阐明了它们各自的原理、技术特点和关键课题；着重指出了两者间的异同和相互联系。     

惯性约束聚变靶场激光束精密调焦及诊断技术

主要介绍了惯性约束聚变靶场精密调焦和诊断的实验系统,阐述了系统采用的谐波驱动器、调焦判据、图象处理等关键技术,实验中通过计算机控制采集到一系列轴向位移和相应焦斑面积的数据,可拟合出位移面积的函数变化曲线, 根据此曲线便可快速准确地确定焦面位置。     

Modeling of MIG/MAG welding with experimental validation using an active contour algorithm applied on high speed movies

This paper investigates some issues in physical modeling of metal inert gas/metal active gas (MIG/MAG) welding process in the short arc mode. In this mode, a metal supply is molten in the arc state and then transferred to the weld pool during the short-circuit state. A hybrid model having two distinct continuous states whose switchings are controlled by two guard conditions is proposed. Due to the complexity of the physical phenomena involved in the welding process, simplifications are used to obtain a model accounting for the main physical contributions but simple enough to yield an efficient, fast and numerically tractable simulator which can be used intensively for evaluating different control strategies. In an attempt to validate the proposed model, different measurements have been made including supply voltage and current sampled synchronously with high speed digital video. In order to extract some relevant quantities representative of the metal transfer from image sequences, an active contour algorithm is developed and tested. The effectiveness of the proposed model in the prediction of major tendencies of a welding process, especially in the arc state, is shown using experimental data. Some limitations of the model during the metal transfer are also stressed and possible remedies are then proposed.     

Effect of glutaphen on generation of active oxygen species, photosynthetic electron transport, and the functional activity of photosystem 2 in Chlorella cells

Treatment of chlorella green algae (Chlorella sp.) for 2 h in the dark with the photodynamic herbicide glutaphen (GTP), consisting of 0.3 mM 1,10-phenanthroline and 0.6 mM glutamic acid, followed by illumination leads to efficient generation of active oxygen species (AOS). After 15 min of illumination, AOS accumulation reaches 200% compared with the level in cells of the control culture, then it decreases down to 130% and 115% after 1 day and 3 days of illumination. During the first few days after treatment, we observe inhibition of synthesis of a specific precursor of chlorophyll (Chl): 5-aminolevulinic acid molecules, and then we observe stimulation of the synthesis. The effect of GTP on the photosynthetic activity of chlorella does not depend on the AOS level but rather remains uniform, in contrast to its effect on the Chl biosynthesis system. GTP does not change the efficiency of light harvesting and charge separation at the reaction centers of photosystem (PS) 2, but significantly lowers the functional efficiency of the electron transport chain: the photochemical quenching constants for Chl a fluorescence and the effective quantum yield of photochemical reactions in photosystem 2 decrease. The major mechanism of action for GTP is probably displacement of the secondary quinone acceptor Q_B from its binding site on the D1 protein by the 1,10-phenanthroline, consequent inhibition of electron efflux from Q _A ⁻ and increase in the fraction of Q_B-nonreducing centers of PS 2. The active oxygen species generated in the cells have a photodegradative effect on the Chl biosynthesis system, in particular on its initial steps, and do not involve already formed pigment-protein complexes of PS 2. __________ Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 73, No. 6, pp. 801–806, November–December, 2006.     

193nm光刻曝光系统的现状及发展

投影曝光工艺是集成电路制造过程中的关键环节,曝光系统的工艺水平已成为衡量微电子制造技术的重要标志。重点介绍了目前193 nm光刻设备曝光系统的发展现状和趋势,以及为提高曝光质量所采用的相关分辨率增强技术;通过分析曝光系统的构成和其中的关键技术,探讨了国内研制相关曝光设备所面临的挑战。     

Direct model-based predictive control scheme without cost function for voltage source inverters with reduced common-mode voltage

This paper presents a direct model-based predictive control scheme for voltage source inverters (VSIs) with reduced common-mode voltages (CMVs). The developed method directly finds optimal vectors without using repetitive calculation of a cost function. To adjust output currents with the CMVs in the range of –V_dc/6 to +V_dc/6, the developed method uses voltage vectors, as finite control resources, excluding zero voltage vectors which produce the CMVs in the VSI within ±V_dc/2. In a model-based predictive control (MPC), not using zero voltage vectors increases the output current ripples and the current errors. To alleviate these problems, the developed method uses two non-zero voltage vectors in one sampling step. In addition, the voltage vectors scheduled to be used are directly selected at every sampling step once the developed method calculates the future reference voltage vector, saving the efforts of repeatedly calculating the cost function. And the two non-zero voltage vectors are optimally allocated to make the output current approach the reference current as close as possible. Thus, low CMV, rapid current-following capability and sufficient output current ripple performance are attained by the developed method. The results of a simulation and an experiment verify the effectiveness of the developed method.     

Developments in electrochemical processes for recycling lead–acid batteries

The lead–acid battery recycling industry is very well established, but the conventional pyrometallurgical processes are far from environmentally benign. Hence, recent developments of lead–acid battery recycling technologies have focused on low-temperature (electro)hydrometallurgical processes, the subject of this review, covering modified electrolytes, improved reaction engineering, better reactor design and control of operating conditions.