WEAK CONVERGENCE OF HENSTOCK INTEGRABLE SEQUENCES

Some relationships between pointwise and weak convergence of a sequence of Henstock integrable functions are studied, In particular it is provided an example of a sequence of Henstock integrable functions whose pointwise limit is different from the weak one. By introducing an asymptotic version of the Henstock equiintegrability notion it is given a necessary and sufficient condition in order that a pointwisely convergent sequence of Henstock integrable functions is weakly convergent to its pointwise limit.     

APEC会议的“东亚之困”

正只有空洞的"共识",没有实际成果政治上的摩擦,必然阻碍东亚三国的经济一体化进程。向来被戏称为"寻找空洞共识"的亚太经合组织(以下简称APEC)峰会在俄罗斯远东港口城市符拉迪沃斯托克落下帷幕。尽管每年多达十余国的元首和部长不远万里齐聚一堂举行会议,但在五花八门的全球经济或政治组织中,APEC始终上不了台面,入不了主流。原因很简单。1989年成立于澳大利亚的APEC组织诞生之日起到现在已经有23年之久,在经过无数次会晤后,该组织除了一次次发表"与会各方在某某方面达成共只"之外,始终没有任何实质性成果问世。促进亚太地区的自由贸易和经济一体化这一宏大     

RELATIVELY WEAKLY COMPACT SETS IN THE DEN JOY SPACE

Some topological Properties of the completion H of the Denjoy space are studied. In particular sufficient conditions for a subsets of H be relatively compact and characterizations for a subsets of H be restively weakly compact are given.     

Achievement of Narrow-Band CARS Signal by Manipulating Broad-band Laser Spectrum

We theoretically demonstrate the achievement of narrow-band coherent anti-Stokes Raman scattering （CARS） signal by manipulating broad-band probe spectrum. The narrowing of the CARS signal depends on the spectrum bandwidth of the probe beam, and thus high-resolution CARS signal for a complicated quantum system can be obtained by the simple spectrum manipulation. Furthermore, the energy-level diagram for the complicated quantum system can also be labelled by measuring the CARS signal at a given frequency.     

神奇的“脑控”技术

正一个人通过脑电波对另一人的大脑进行"控制",这听起来像是科幻小说中的情节。然而,近日美国科学家首次成功进行了一次人脑"意识融合"试验,让科幻成为现实。位于美国西雅图的华盛顿大学计算机科学和工程教授罗杰西·拉奥日前在该校进行了一次试验。拉奥坐在学校的实验室里,头部通过电极与一台脑电图描记器相连。此时,在校园另一侧,拉奥的同事安德里亚·斯托克头戴一顶装有经颅磁刺激线圈的紫色游泳帽,线圈正好对准控制他右手活动的头部左运动皮层。拉奥注视着电脑屏幕,想象自己正在操纵一个电子游戏,并在游戏中用右手发射火炮,此时他的手并没有动。脑电图描记     

The liquid phase separation of Bi-Ga hypermonotectic alloy under acoustic levitation condition

Containerless treatment of Bi-58.5at%Ga hypermonotecUc alloy is successfully performed with acoustic levitation technique. Under acoustic levitation condition, the second phase （Ga） distributes almost homogeneously in solidification sample, opposite to macrosegregation in solidification sample under conventional condition. Stokes motion of the second liquid droplet （Ga） is significantly restrained under acoustic levitation condition. The analyses indicate that the melt vibration in the gravity direction forced by acoustic field can induce steady flow around the second liquid droplet, which influences droplet shape during its moving upward and consequently restrains Stokes motion velocity of the second liquid droplet.     

自由活塞激波风洞

自由活塞激波风洞是一种使用自由活塞压缩器驱动的高焓脉冲型激波风洞。这种风洞是由R J Stalker提出并在澳大利亚国立大学首先建成和逐渐发展起来的高焓实验设备。经过30多年的改进与发展,日趋完善,现已成为研究高超声速气动加热、计及真实气体效应的气体动力学现象、特别是超声速或高超声速燃氢冲压发动机(scamjet)的重要设备之一,受到国际上航空航天界的重视。本文概述了自由活塞激波风洞的发展过程,系统地阐述了这种设备的结构特点和运行原理,给出了性能参数的计算方法和算例,及其性能指标,并讨论了这类风洞的优缺点。      

无菌世界很可怕 脏东西对宝宝有好处

正数以百万的细菌、病毒、尤其是蠕虫之类的生物体随着"脏东西"进入人体,能促进孩子免疫系统的健康发展。曾经有一个育儿专家出过这样一道选择题,当宝宝的奶嘴掉到地上,你应该怎么做?第一种用奶嘴蘸温水刷一遍,然后放入蒸汽锅中     

密立根油滴实验中运动速度的分析

通过对带电全程推导分析,而只是选取油滴匀速运动的区域进行测量。通过对带电全程推导分析,得到结果发现油滴在极短时间内就近似达到了极限速度,因此对于匀速区域的选取并不需要特别说明,实验本身的设计是十分合理。