压电陶瓷微位移器件迟滞模型的研究

在通过统计物理学角度分析压电陶瓷迟滞规律的基础上，结合数学建模方法，提出了一种简单实用的压电陶瓷迟滞数学模型。并设计了压电陶瓷实验控制系统，对迟滞数学模型进行了验证，实验结果表明，此模型可以有效减小压电陶瓷的迟滞非线性误差，提高压电陶瓷微位移的控制精度，本研究有助于实现基于压电陶瓷的高精度开环微位移控制。     

万年历还剩93年

手表显示日期看上去是一个基础简单的功能。但是每当碰到闰年、闰月的情况，大部分的机械手表都需要手动调整日期来纠正显示错误。为了解决这个技术上的难题，万年历手表诞生了。[编者按]     

应用于雷达和通信中的砷化镓低噪声单片微波集成放大器

<正> 一、引言单片微波集成电路已不再是实验室的奇迹了,它已在世界各公司开发并投入试制性的生产。把模拟功能集成在小块 GaAs 单片上的好处是子系统的尺寸可减小到 1/10,部件成本和装配次数大大减少,并且实现了比混合电路更复杂的功能。已经用增强型技术在高速、低功耗 GaAs 数字电路方面做了大量的工作。到目前为止,模拟单片集成电路已经广泛地应用在先进的相控阵雷达中,为了使这种系统获得成功,必须满足在成本、可靠性、重复性和性能诸方面的要求。目前,正在考虑把相控     

融合创意产业的民族手工艺品发展策略

文章首先介绍湖南、贵州等地少数民族手工艺产品的当代状况,并从传统工艺的文化的传承和资本的流动的角度进行了分析。之后,文章简介了台湾省内对于创意产业的发展的部分经验,总结融合创意产业发展少数民族手工艺产品的发展策略。     

Computation of surface orientation and structure of objects using grid coding

In this correspondence, algorithms are introduced to infer surface orientation and structure of visible object surfaces using grid coding. We adopt the active lighting technique to spatially ``encode' the scene for analysis. The observed objects, which can have surfaces of arbitrary shape, are assumed to rest on a plane (base plane) in a scene which is ``encoded' with light cast through a grid plane. Two orthogonal grid patterns are used, where each pattern is obtained with a set of equally spaced stripes marked on a glass pane. The scene is observed through a camera and the object surface orientation is determined using the projected patterns on the object surface. If the surfaces under consideration obey certain smoothness constraints, a dense orientation map can be obtained through proper interpolation. The surface structure can then be recovered given this dense orientation map. Both planar and curved surfaces can be handled in a uniform manner. The algorithms we propose yield reasonably accurate results and are relatively tolerant to noise, especially when compared to shape-from-shading techniques. In contrast to other grid coding techniques reported which match the grid junctions for depth reconstruction under the stereopsis principle, our techniques use the direction of the projected stripes to infer local surface orientation and do not require any correspondence relationship between either the grid lines or the grid junctions to be specified. The algorithm has the ability to register images and can therefore be embedded in a system which integrates knowledge from multiple views.     

Parallel 2-d convolution on a mesh connected array processor

In this correspondence, a parallel 2-D convolution scheme is presented. The processing structure is a mesh connected array processor consisting of the same number of simple processing elements as the number of pixels in the image. For most windows considered, the number of computation steps required is the same as that of the coefficients of a convolution window. The proposed scheme can be easily extended to convolution windows of arbitrary size and shape. The basic idea of the proposed scheme is to apply the 1-D systolic concept to 2-D convolution on a mesh structure. The computation is carried out along a path called a convolution path in a systolic manner. The efficiency of the scheme is analyzed for windows of various shapes. The ideal convolution path is a Hamiltonian path ending at the center of the window, the length of which is equal to the number of window coefficients. The simple architecture and control strategy make the proposed scheme suitable for VLSI implementation.     

五氯酚钠灭螺缓释剂研究(第二报)

近两年来,我们对五氯酚钠缓释剂的剂型加工和药效试验又作了进一步研究,现将研究结果报告如下: 一、制备工艺我们对灭螺缓释剂的制备工艺,主要作了以下几方面的研究。(一)灭螺药物的选择可用于杀灭钉螺的药物很多,但灭螺效果