DIRECT RESONANCE OF TURBULENT BOUNDARY LAVER OVER COMPLIANT WALLS

１．　ＩＮＴＲＯＤＵＣＴＩＯＮＴｈｅｍａｉｎｇｏａｌｏｆｔｈｉｓｐａｐｅｒｉｓｔｏｅｘｐｌｏｒｅｔｈｅｐｏｓｓｉｂｉｌｉｔｙｔｏｌｅａｒｎｍｏｒｅａｂｏｕｔｔｈｅｍｅｃｈａｎｉｓｍｏｆｔｕｒｂｕｌｅｎｔｂｏｕｎｄａｒｙｌａｙｅｒｆｌｏｗｉｎｔｅｒａｃｔｉｏｎｓａｎｄｉｔｓｅｆｆｅｃｔｓｏｎｃｏｍｐｌｉａｎｔｗａｌｌｐｅｒｆｏｒｍａｎｃｅ．Ｔｈｅｒｅａｒｅｃｅｒｔａｉｎｐｒｅｒｅｑｕｉｓｉｔｅｃｏｎｄｉｔｉｏｎｓｔｏｆｕｒｔｈｅｒｔｈｅｓｔｕｄｙｏｎｔｈｅｍｅｃｈａｎｉｓｍ，ｉ．ｅ．ｔｈｅｃｏ…     

新加坡电影业和数字影院技术的发展概况

近年来，在新加坡政府的支持及各项政策的推动下，新加坡数字技术应用和网络资讯科技的发展位于世界领先地位，特别是电影放映业取得较大发展，票房收入不断提高。为了解新加坡数字电影放映技术的最新发展情况及其市场运作模式，3月27日至4月1日，中国电影科研所电影技术考察组在新加坡进行了为期4天的专访和考察。考察期间我们与新加坡有关政府部门的代表、相关公司的主要负责人和技术专家进行了交流和座谈，现将考察情况综述如下。     

Special issue on wireless sensor networks: from theory to practice

Wireless sensor network(WSN)is characterized by the dense deployment of sensor nodes that continuously observe physical phenomenon.The main advantages of WSN include its low cost,rapid deployment,self-organization,and fault tolerance.WSN has received tremendous interests of various research communities,and significant progresses have been made in various aspects including sensor platform development,wireless communication and networking,signal and information processing,as well as network performance evaluation and design.Such work has established good foundation     

Optical and Structural Properties of In_(0.52)Al_(0.48)As/InP Structures Grown at Very High Arsenic Overpressures by Molecular Beam Epitaxy

Growth of ln0.52Al0.48As epitaxial layers on lnP(100) substrates by molecular beam epitaxy at a wide range of arsenic overpressures (V/III flux ratios from 30 to 300) has been carried out. Analysis performed using low-temperature photoluminescence (PL) and double-axis X-ray diffraction (XRD) shows a strong and prominent dependence of the PL and XRD linewidths on the V/III flux ratio. Under our growth conditions, both the PL and XRD linewidths exhibit a minimum point at a V/III flux ratio of 150 which corresponds to a maximum in the PL intensity and XRD intensity ratio. Flux ratios exceeding 150 result in an increase in both the PL and XRD linewidths corresponding to a reduction in their associated intensities. Room temperature Raman scattering measurements show a narrowing in the lnAs-like and AlAs-like longitudinal-optic (LO)phonon linewidths which broaden at high flux ratios, while the LO phonon frequencies exhibit a gradual reduction as the flux ratio is increased. PL spectra taken at increasing temperatures show a quenching of the main emission peak followed by the evolution of a broad lower energy emission which is possibly associated with deep lying centres. This effect is more prominent in samples grown at lower V/III flux ratios. Hall effect measurements show a gradual reduction in the mobility in correspondence to an increase in the electron concentration as the flux ratio is increased.     

FLOCCULATION/COAGULATION OF NATURAL ORGANIC MATTER FOR PRETREATMENT OF WATER AND WASTE WATER

Characterization of water, waste water and natural organic matter are involved in this paper, and as well as the features of flocculation and coagulation for removing natural organic matter from water and waste water Novel flocculant and coagualant is strongly asked for improving removal efficiency and environment friendly. Enhanced coagulation is introduced to meet the experimental and practical requirement.     

高温热管在硫酸工业余热回收中的应用

将高温热管蒸汽发生器应用于硫酸生产工艺,回收了大量的ＳＯ２炉气高温余热,解决了硫酸生产工艺炉气降温的难题,取得了很好的经济效益和社会效益。     

陕西省信息大厦超高层结构设计和安全性分析

陕西省信息大厦结构设计有以下特点:(1)是目前国内8度抗震设防地区最高的超限高层钢筋混凝土组合简体结构,主楼高189.4m;(2)国内首次在黄土地区采用68m长的超长钻孔灌注桩;(3)为减少建筑物高度,7～48层采用部分无粘结预应力混凝土板结构;(4)进行了结构弹塑性分析,包括静力推覆(Pushover)分析和动力反应时程分析。     

Repetitive learning control of nonlinear systems over finite intervals

Iterative learning control requires initial repositioning, while the time functions to be learned should be of periodicity in repetitive control. However, there are cases in practice where the time-varying unknowns are not periodic but repetitive, and repetitive learning control is applicable with avoidance of initial repositioning. In this paper, repetitive learning control designs are presented for a broader class of nonlinear systems over finite intervals. The Freeman formula is modified and used for sta...     

元素掺杂类金刚石碳膜降内应力研究综述

我国汽车行业与国际同行的差距主要在于发动机关键零部件的摩擦磨损。类金刚石(DLC)碳膜技术是解决发动机关键零部件摩擦磨损问题的有效途径,但传统的DLC碳膜在制备过程中会产生较高的内应力(可达10GPa),从而导致薄膜失效。首先分析了DLC碳膜在汽车零部件领域的应用背景,探讨了薄膜内应力的来源,重点综述了异质元素掺杂降低类金刚石碳膜内应力的研究现状。常用掺杂元素按化学性质可分为碳化物形成元素与非碳化物形成元素,不同于其他分类方法,笔者按掺杂元素的组元多少进行划分,从单元掺杂、二元或多元掺杂入手,系统分析了各种掺杂方式、掺杂元素的优缺点。在此基础上,指出元素掺杂降低类金刚石碳膜内应力的研究从最初的单一元素掺杂,逐步发展到了二元或多元元素掺杂;从碳化物形成元素掺杂、非碳化物形成元素掺杂,逐步发展到碳化物形成元素与非碳化物形成元素的多元共掺杂;所研究的类金刚石碳膜的显微结构也从最初的非晶态结构向多元、多相结构发展,以期获得良好的综合机械性能。