基于不同颜色背景的人眼辨色阈值特性研究

为了研究不同颜色背景对人眼辨色阈值特性的影响,在CIE1976L*a*b*平面上,基于心理物理学的交叉阶梯法测得国际照明委员会(CIE)推荐的5个基本颜色中心分别在该五个颜色背景下的辨色阈值.通过对辨色阈值椭圆的详细分析表明,同一颜色中心的辨色阈值在不同颜色背景下的局部视觉均匀性总体上保持相对稳定,而不同颜色中心的色度...     

“免费”是成功的新典范？——以可持续方式从服务提供商的核心资源中赚钱

通过部署永远在线的宽带基础设施，服务提供商使这些新形式的使用和消费成为可能。为了能在这些服务上进一步产生收益，服务提供商需要超越现有的基于服务订阅的收入来源模式而采用利用internet和Web2．0周边新动力的商业模式。     

From micro-to nanosized particles:Selected characterization methods and measurable parameters

Airborne microand nanoparticles-aerosols-play an important role in many natural phenomena and in a variety of industrial processes,as well as the public health issue. They may be of natural or anthropogenic origin;their presence in an environment might be intentional or due to undesirable release. In any case,merely the particle detection and characterization,ideally in real-time,provide an insight into the potential burden allowing also controlling and abatement measures. Due to the broad size range it is ...     

云南广播电视台新闻节目收录系统

新闻节目中的素材有相当部分是由演播室中的节目收录系统提供的。我台新闻中心节目收录有新老两个系统同时在运行。老系统建设于2003年，采用传统方式，通过收录网点用磁带录像机稳定运行，但也存在不少弊端。特别是最近四五年，自办栏目需求和节目收录数量都逐年增加，传统方式在资源、效率、共享等方面的弊端日益突出。2008年，随着我台开始建设全台网，网络化、数字化的新系统也开始建设，并于2009年投入使用．能自动、高效地完成收录任务。     

我们才刚刚开始调整关于照片保存的文化假想

也许,我们会发现,趋势的发展指向马歇尔·麦克卢汉对于新媒体所描述的倒车镜关系：我们倾向于做的第一件事是模仿他们取代的。其逻辑是,介绍数码影像时,我们用它来复制模拟照片的样子。1977年,在纽约国际摄影中心,最新的美国摄影师William De Lappa展示了一系列名为＂紫罗兰和Al的肖像＂的黑白图片。这些照片旋转在标题周围,看起来好像是20世纪40年代晚期至60年代早期不同人们的收集的几十张照片。     

Non-contact evaluation of the resonant frequency of a microstructure using ultrasonic wave

This paper presents a novel non-contact method for evaluating the resonant frequency of a microstructure, Firstly, the microstructure under test is excited by ultrasonic waves. This excitation method does not impose any undefined load on the specimen like the electrostatic excitation and also this is the first actual use of ultrasonic wave for exciting a microstructure in the literature. Secondly, the amplitudes of the microstructure are determined by image edge detection using a Mexican hat wavelet transform on the vibrating images of the microstructure. The vibrating images are captured by a CCD camera when the microstructure is vibrated by ultrasonic waves at a series of discrete high frequencies （〉30 kHz）. Upon processing the vibrating images, the amplitudes at various excitation frequencies are obtained and an amplitude-frequency spectrum is obtained from which the resonant frequency is subsequently evaluated. A micro silicon structure consisting of a perforated plate （192 × 192 μm） and two cantilever beams （76 × 43 μm） which is about 4 μm thickness is tested. Since laser interferometry is not required, thermal effects on a test object can be avoided. Hence, the setup is relatively simple. Results show that the proposed method is a simple and effective approach for evaluating the dynamic characteristics of microstructures.     

浅谈新疆人民广播电台CAS播出网

本文介绍了新疆人民广播电台CAS播出系统两大部分的功能，以及实际运用中的功效与作用。     

Free vibration of functionally graded sandwich plates using four-variable refined plate theory

This paper uses the four-variable refined plate theory (RPT) for the free vibration analysis of functionally graded material (FGM) sandwich rectangular plates.Unlike other theories, there are only four unknown functions involved, as compared to five in other shear deformation theories. The theory presented is variationally consistent and strongly similar to the classical plate theory in many aspects. It does not require the shear correction factor, and gives rise to the transverse shear stress variation so that the transverse shear stresses vary parabolically across the thickness to satisfy free surface conditions for the shear stress. Two common types of FGM sandwich plates are considered, namely, the sandwich with the FGM facesheet and the homogeneous core and the sandwich with the homogeneous facesheet and the FGM core. The equation of motion for the FGM sandwich plates is obtained based on Hamilton's principle. The closed form solutions are obtained by using the Navier technique. The fundamental frequencies are found by solving the eigenvalue problems. The validity of the theory is shown by comparing the present results with those of the classical, the first-order, and the other higher-ordex theories. The proposed theory is accurate and simple in solving the free vibration behavior of the FGM sandwich plates.