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1.
压电和声波理论与器件设计密切相关,特别是压电谐振器的工作原理就是材料中弹性波的压电效应。在信息技术高度发达的今天,压电谐振器作为最基本和最常见的敏感元件,在所有的通讯技术、电子电路、传感器和基于换能器的智能结构中都有着广泛的应用,也激发了固体力学界对这一现象展开大量的理论研究工作。可以说,压电现象作为桥梁将固体力学这一传统学科和新兴的信息技术、生物技术和近年来迅速发展的微机电(MEMS)技术等领域有机地联系了起来,无论从科学研究和工程应用的角度,都赋予了固体力学新的机会和生命力,也为研究和技术人员提供了具有… 相似文献
2.
陈伟球 《中国科学院研究生院学报》1983,21(4):386-403
This paper presenta a brief introduction to the taxonomy and geographic distribu-
tion of the genus Wendlandia.
The genus Wendlandia in tribe Rondeletieae of the family Rubiaceae was proposed by Bartling in 1830. There are now more than ninety species throughout the world. It is distributed mainly in tropical and subtropical Asia. Thirty species, ten subspecies and three varieties are recorded in the paper. Among these, nine species, two subspecies and one variety are new. They are distributed mainly in Yunnan, Guizhou, Guangxi, Guangdong, Xizang and Taiwan Provinces. Only one species, namely W. longidens (Hance) Hutch. Extends northward to Hubei and Sichuan.
The classification of the genus in this paper is based on Cowan's system. It is divided into four series mainly by their stigmatic and staminal characters, namely Euexsertae, Subinclusae, Montigenae and Clavigerae. The first two series are each subdivided according to the stipule feature into two subseries, designated as Cuspidatae, Orbiculares, Tinctoriae and Paniculatae.
From the distribution patterns of the genus in the flora of China, we may understand:
1. The genus has the most species in China, where is its distribution centre, and Yurnan is the province richest in species of the genus.
2. There are twenty-one species, five subspecies and three varieties endemic to China. Most of these endemics have their distributional area confined to a single province, and some of them are confined to an even narrower district, with only a few of them extending beyond province boundaries.
3. The series Subinclusae Cowan has the most species not only in China but also in other regions of the world, whereas the series Montigenae Cowan has fewer species and they are all restricted to China.
The new species, new subspecies and the new varieties described in this paper are as follows: W. brevipaniculata W. C. Chen, W..villosa W. C. Chen, W. tinctoria (Roxb.)
DC. subsp. affinis How, W. laxa S. K. Wu, W. uvariifolia Hance subsp. pilosa W. C. Chen,
W. guangdongensis W. C. Chen, W. parviflora W. C. Chen, W. scabra Kurz var. pilitera
How, W. pubigera W. C. Chen, W. jingdongensis W. C. Chen, W. brevituba Chun et Howand W. oligantha W. C. Chen. 相似文献
3.
ＩＮＴＲＯＤＵＣＴＩＯＮＡｓｋｎｏｗｎ ,ｔｈｅｒｍａｌｂｅｈａｖｉｏｒｓｏｆｓｔｒｕｃｔｕｒｅｓｍｕｓｔｂｅｃｏｎｓｉｄｅｒｅｄｉｎｍａｎｙｓｉｔｕａｔｉｏｎｓ.Ｓｔｕｄｙｏｆｔｈｅｒｍａｌｅｆｆｅｃｔｏｎｄｅｆｏｒｍａｔｉｏｎｓａｎｄｓｔｒｅｓｓｅｓｏｆ 相似文献
4.
A bi-harmonic potential function was constructed in this study. Love solution was employed to obtain analytical solutions of uniformly loaded plates with two different types of clamped edges. The treatment of clamped boundary conditions was the same as that adopted by Timoshenko and Goodier （1970）. The analytical solution for the first type of clamped boundary condition is identical with that obtained by Luo et al.（2004）, and the solutions for both types were compared with the FEM results and the calculations of thin plate theory. 相似文献
5.
This paper presents an overview of the recent progress of potential theory method in the analysis of mixed boundary value problems mainly stemming from three-dimensional crack or contact problems of multi-field coupled media. This method was used to derive a series of exact three dimensional solutions which should be of great theoretical significance because most of them usually cannot be derived by other methods such as the transform method and the trial-and-error method. Further, many solutions are obtained in terms of elementary functions that enable us to treat more complicated problems easily. It is pointed out here that the method is usually only applicable to media characterizing transverse isotropy, from which, however, the results for the isotropic case can be readily obtained. 相似文献
6.
陈伟球 《中国科学院研究生院学报》1990,28(4):299-306
This paper presents an introduction to the materials for Chinese Galium
Linn. (Rubiaceae). Thirteen species and eight varieties are recorded in the paper.
Among these, two species and two varieties are new, eleven species and five varietiesare new to China, and one variety is a new grade. 相似文献
7.
The separation of variables method was successfully used to resolve the spherically symmetric dynamic thermoelastic problem for a spherically isotropic elastic hollow sphere. Use of the integral transform can be avoided by means of this method, which is also appropriate for an arbitrary thickness hollow sphere subjected to arbitrary thermal and mechanical loads. Numerical results are presented to show the dynamic stress responses in the uniformly heated hollow spheres. 相似文献
8.
9.
EXACT SOLUTION OF AN EXTERNAL CIRCULAR CRACK IN A PIEZOELECTRIC SOLID SUBJECTED TO SHEAR LOADING 总被引：4，自引：0，他引：4
ＩＮＴＲＯＤＵＣＴＩＯＮＤｕｅｔｏｔｈｅｉｎｈｅｒｅｎｔｗｅａｋｎｅｓｓｏｒｂｒｉｔｔｌｅｎｅｓｓｏｆｐｉｅｚｏｅｌｅｃｔｒｉｃｃｅｒａｍｉｃｓ,ｔｈｅｆｒａｃｔｕｒｅｏｆｐｉｅｚｏ ｅｌｅｃｔｒｉｃｍａｔｅｒｉａｌｓｈａｓｇａｉｎｅｄｃｏｎｓｉｄｅｒａｂｌｅｉｎｔｅｒ ｅｓｔ.Ｍｏｓｔｐｕｂｌｉｓｈｅｄｗｏｒｋｓｄｅａｌｔｗｉｔｈｔｗｏ ｄｉｍｅｎ ｓｉｏｎａｌｓｔｕｄｙｏｆｃｒａｃｋｓｉｎｐｉｅｚｏｅｌｅｃｔｒｉｃｍａｔｅｒｉａｌｓ(Ｐａｋ ,1 990 ;Ｓｕｏｅｔａｌ.,1 992 ;ＺｈｏｎｇａｎｄＭｅｇｕｉ… 相似文献
10.
陈伟球 《河南科技学院学报》2012,(12):80-82
与传统的职业课程相比,加拿大CBE教育模式具有明显的优势和特征,它更注重学生职业能力的培养,更关注行业的需求。对我国职业教育尤其是与新兴产业相关的职业教育来说,要学习加拿大CBE教育模式的精髓,强调以职业需求为导向,与行业紧密结合,共同设计课程体系及内容,并努力搭建公共实训平台突出职业教育特色。 相似文献