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1.
ＩＮＴＲＯＤＵＣＴＩＯＮＴｈｅｒｅａｒｅｒｅｐｏｒｔｓｏｆｅｘｔｅｎｓｉｖｅｉｎｖｅｓｔｉｇａｔｉｏｎｓｏｎｔｈｅｐｒｅｃｉｐｉｔａｔｉｏｎａｎｄａｇｅｉｎｇｈａｒｄｅｎｉｎｇｏｆＡｌ Ｃｕ Ｍｇａｌｌｏｙｓ (Ｃｈｅｎｅｔａｌ.,1 997;Ｓｈｉｈｅｔａｌ.,1 996;Ｈｕａｎｇｅｔａｌ.,1 995) .Ｃｏｐｐｅｒａｎｄｍａｇ ｎｅｓｉｕｍｃｏｎｔｒｉｂｕｔｅｔｏｔｈｅｐｒｅｃｉｐｉｔａｔｉｏｎｈａｒｄｅｎｉｎｇａｔｔｅｍｐｅｒａｔｕｒｅｓｏｆｕｐｔｏ 2 0 0℃ .ＡｄｄｉｔｉｏｎｓｏｆｉｒｏｎａｎｄｎｉｃｋｅｌｔｏＡ… 相似文献
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设 G 是一个带有单位元的离散群,H 是域 k 上的拟三角 Hopf G-余代数。考虑了 H 的 G-群像元和ribbon 元之间的关系。首先证明了拟三角 Hopf G-余代数以及它的 Drinfeld 元的一些重要性质。受到 Hopf代数中群像元和 ribbon 元之间关系的启发,定义了一类特殊的 G-群像元。最后利用 Drinfeld 元得到了所定义的特殊的 G-群像元和 ribbon 元之间的一个一一对应关系。 相似文献
3.
朱芋静 《绵阳师范学院学报》2008,27(12)
针对目前用地区域存在的诸多问题提出了“绿脊、蓝带、红色足迹”的城市设计理念,试图重新定义城市架构和脉络,使城市的绿色脊梁和蓝带空间能完美地结合,从而创造可持续发展的活力城市空间;同时,创建一个新的景观架构以强调复杂的文化体系、历史背景以及土地、水与城市之间的生态关系中的连通性。 相似文献
4.
刘荣生 《闽西职业技术学院学报》2006,8(4):124-125
在带式输送机传动装置中,V带对一级直齿圆柱齿轮减速器主动轴拉力方向不同,则主动轴的抗弯刚度和抗弯扭强度不一样。合理的布局方案应该使V带对主动轴的拉力方向有利于减少主动轴的总弯曲变形以提高它的抗弯刚度,有利于减少主动轴在水平面上的弯矩以提高它的抗弯扭强度。 相似文献
5.
A commercial AA2618 alloy was treated through melt spinning at rotating speeds of 20 and 40 m·s−1. The as-melt spun ribbons were characterized by a combination of optical microscopy (OPM), scanning electron microscopy (SEM),
transmission electron microscopy (TEM) and X-ray diffraction (XRD). The microstructural evolution of the ribbons in a continuous
heating process was investigated, and the microhardness was also measured under different conditions. It was found that Al
x
FeNi is prone to precipitate in AA2618 alloy due to the minimal solubility of iron and nickel. Fine Al
x
FeNi particles appeared along the grain boundaries at the chilling sides of as-melt spun ribbons, and at both the grain boundaries
and in the interior of grains at the free sides. On continuous heating Al
x
FeNi precipitated steadily and uniformly throughout the matrix until melting. The microhardness of as-melt spun ribbons decreased
significantly from the chilling surfaces to free surfaces. Precipitation of Al
x
FeNi lowered the hardness of the alloy.
Project supported by Special Research Foundation of High-Education Ph. D. Subjects, Education Ministry of P. R. China. 相似文献
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In order to constitute engineering design methods of the flat ribbon wound explosion containment vessels, the dynamic response of such vessels subjected to internal explosion loading is simulated using LS-DYNA3D. Three winding angles, 10°, 15°and 20°, are considered. It is shown that among ribbon vessels investigated, the center displacement of outermost ribbons of the vessel with 10°winding angle is the smallest under the same blast loading. The response of vessels loaded in inner core is local. From the center of the cylindrical shell to the bottom cover, the maximum strain gradually decreases. The ribbons are subjected to tension in the length direction and compression in the width direction. Blasting shock energy concentrates on where is close to center section of blasting. For comparison, numerical simulation of a monobloc thick-walled explosion containment vessel is also investigated. It can be found that the biggest deformation of the flat ribbon wound explosion containment vessels is bigger than that of the monobloc thick-walled explosion containment vessel in the center section of blasting under the same TNT. Numerical results are approximately in agreement with experimental ones. It is proved that the ribbon vessels have the valuable properties of " leak before burst at worst" compared with the monobloc vessels through numerical simulation. 相似文献
8.
全伟 《洛阳师范学院学报》2001,20(2):115-116
本文从跑、跳、投、素质、体操、球类、跳台跳水、游戏等七个方面 ,讲述了橡皮带在体育教学中的巧妙运用 .它可以起到标志线、增强肌肉力量、固定球的空中位置、做体操、游戏的器械、以及保护、帮助等作用 相似文献
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CUI Xiao-long CHEN Guang-ming 《浙江大学学报(A卷英文版)》2007,8(2):210-215
INTRODUCTION Cryogenic high-pressure vessels are used to store liquid hydrogen and liquid oxygen, and are necessary equipments in the fields of chemical engineering, astronautic engineering and nuclear power plant, and so on. Safe operation of the vessel is always a concern of environmental protection. The inner pressure of the vessel can reach 40 MPa at temperature of 20 K; Therefore, the vessel requires high-performance wall material excellent in mechanical strength, plastic property,… 相似文献
10.
本研究运用单一被试实验法、观察法和测试法 ,对宁波盲校小学部 1 996级1 0名学生点字书写的 4年研究发现 :盲童使用点字板 (笔 )和使用盲文打字机的书写效果不同 ,使用盲文打机比使用点字板 /笔书写速度快 2倍 ,使用盲文打字机书写效率较高 ;盲童使用不同规格点字板、点字笔和纸张对点字书写速度有一定影响。 相似文献