检索结果-南通市图书馆

在线全文

学校读者我要写书评

暂无评论

泡沫铝的低频内耗特征研究

物理学报 1997年第8期46卷 1585-1592页

作者：刘长松韩福生朱震刚中国科学院固体物理研究所内耗与固体缺陷开放研究实验室

采用粉末冶金发泡法制备的泡沫铝试样，研究了室温下低频范围（００４—４Ｈｚ）泡沫铝的内耗与孔结构（孔隙率和孔径）、频率、振幅之间的关系．结果表明泡沫铝的内耗具有以下特征：孔径一定时，内耗随孔隙率的增加而增大；孔隙率一... 详细信息

采用粉末冶金发泡法制备的泡沫铝试样，研究了室温下低频范围（００４—４Ｈｚ）泡沫铝的内耗与孔结构（孔隙率和孔径）、频率、振幅之间的关系．结果表明泡沫铝的内耗具有以下特征：孔径一定时，内耗随孔隙率的增加而增大；孔隙率一定时，内耗随孔径的减小而增大；在测量频率范围内，内耗与频率近似无关；小应变振幅时内耗随振幅的增大而增大，具有正常振幅效应．提出了泡沫铝的内耗产生机制，根据等效夹杂方法和钉扎位错内耗特点进行了理论分析。

关键词：内耗测量泡沫金属泡沫铝低频内耗

THE DISTRIBUTION OF PARTICLES IN A SHOCK-INDUCED BOUNDARY LAYER OF A DUSTY GAS OVER A solid SURFACE

在线全文

学校读者我要写书评

暂无评论

Acta Mechanica sinica 1991年第2期7卷 117-122页

作者： Wang Boyi (institute of Mechanics,academia sinica,Beijing,china)S.L.Veselyi V.A.Kulikovskii A.N.Osiptsov (institute of Mechanics,Moscow state University,Moscow,USSR) institute of Mechanics Academia Sinica Beijing China institute of Mechanics Moscow State University Moscow USSR

The laminar boundary layer behind a constant-speed shock wave moving through a dusty gas along a solid surface is *** Saffman lift force acting on a spherical particle in a gas boundary layer is taken into account.A method for calculating the density profile of dispersed phase near the wall is pro- posed and some numerical results are *** is shown that behind the shock wave,there exists a curved thin layer where the density of particles is many times higher than the original *** dust collection effect may be of essential importance to the problem of dust explosion in industry.

关键词： dusty-gas boundary layer distribution of particles Saffman lift force

Phase Relationship in Nd_2(Fe_(1-x)Ni_x)_(14) B and Pr_2(Co_(1-y)Ni_y)_(14)B Pseudo-ternary Compounds

在线全文

学校读者我要写书评

暂无评论

Rare Metals 1989年第2期9卷 17-23页

作者： Wu Changheng zhuang Yuzhi Xie Jinqiang institute of Metal Research,academia sinica.Shenyang 中科院金属所辽宁沈阳

The melting behavior,solid state phase transformation and structure of pseudo-ternary compounds Nd_2(Fe_(1-x)Ni_x)_(14)B and Pr_2(Co_(1-y)Ni_y)_(14)B were studied using differential thermal analysis,optical microscopy X-ray diffraction,and electron probe micro-analysis *** high temperature,eutectoid decomposition R_2(Ni,M)_(17)→R(Ni,M)_5+x-Ni(M) takes place in these two pseudo-ternary compounds,in the composition range x=0.6～1.0 and y=0.3～1.0,*** x(or y)≤0.2,both Nd_2(Fe_(1-x)Ni_x)_(14)B and Pr_2(Co_(1-y)Ni_y)_(14)B are single phase *** phase constitutents of these two systems at room tempera- ture are similar in the composition range 0.6≤x(or y)≤1.0.

关键词： Fe Co B and Pr2 Phase Relationship in Nd2 x)Ni_x y)Ni_y B Pseudo-ternary Compounds Ni Nd

AUGER INVESTIGATION OF THE THERMAL STABILITY OF AMORPHOUS Pd_(80)Si_(20)

在线全文

学校读者我要写书评

暂无评论

Chinese Science Bulletin 1986年第22期31卷 1529-1532页

作者：李宗全何怡贞 institute of solid state physics Academia Sinica Hefei institute of solid state physics Academia Sinica Hefei systematical study of the structural relaxation and crystallization processes of metallic glasses is very important in understanding the thermal stability of these mate-

A systematical study of the structural relaxation and crystallization processes of metallic glasses is very important in understanding the thermal stability of these mate-

关键词： relaxation glasses metallic heating sputtering Si Room ordering slight evident

GALVANOMAGNETIC PROPERTIES OF METALS ATBOILING OF LIQUID HELIUM

在线全文

学校读者我要写书评

暂无评论

Acta Metallurgica sinica(English Letters) 1997年第3期10卷 291-296页

作者： VR. SoBolo.N. Mazurenkoand A.A. Drozd(institute of solid state and Semiconductor physics, ASB P. Brovka Str., 17, Minsk 220072, Belarus) Inst of solid state and Semiconductor Physics Minsk Belarus

Galvanomagnetic properties of metals at boiling point of liquid helium and some prob-lems relating to Joule heating in cylinder conductors are investigated by the method of voltage current characteristics. Radial current under an external coaxial magnetic field is used to get high magnetoresistance of conductor. High level of magnetore-sistance in this geometry offers the possibility to investigate a wide range of heat generation. The stabilization of voltage observed in definite current range is discussed in terms of analysis of heat aspects of problem when a heat genemtion function and heat elimination they are regarded at helium temperuture. An electric temperature ordering of system is proposed as a factor responsible for voltage stabilization when the presence of more heated and less heated sections along conductor radius is connected with negativity of derivative of heat elimination function with respect to temperature between first and second boiling crisis.

关键词： galvanomagnetic property current density critical temperature,cryogenic system

YNi_5 PHASE AND ITS EFFECT UPON PROPERTIES OF Ni_3Al ALLOY

在线全文

学校读者我要写书评

暂无评论

Acta Metallurgica sinica(English Letters) 1992年第3期5卷 183-187页

作者： WANG Shuhe GUO Jianting LI Hui SUN Chao TAN Minghui LAI Wanhui institute of Metal Research,academia sinica,Shenyang,china Inst of Metal Research Acad Sinica Shenyang China

An additive of Y to Ni_3Al based alloy may form a phase YNi_5 which increases in amount with the increase of Y *** was found that the YNi_5 phase in Ni_3Al alloy could remarkably make its grains finer and its grain boundaries more crooked other than *** the Y con- tent≥0.1 wt-%,it occurs as solid solution state and is favorable to high temperature compressive properties and oxidation resistance of the *** Y≥0.3 wt-%,the forma- tion of YNi_5 is predominant in the shape of irregular strips inside Ni_3Al grains and along their grain *** seems to be quite harmful to high temperature strength,ductility and oxidation resistance of the alloy.

关键词： Ni_3Al YNi_5 phase Y compressive property oxidation resistance

在线全文

学校读者我要写书评

暂无评论

聚四氟乙烯薄膜的制备及其红外光谱研究

物理学报 1997年第9期46卷 1764-1767页

作者：朱开贵石建中李可斌姚伟国张立德中国科学院固体物理研究所苏州大学物理系

用射频磁控溅射方法分别在ＮａＣｌ和Ｓｉ基底上制备了聚四氟乙烯薄膜．通过红外吸收光谱的研究分析了薄膜中的成分及分子链结构．

关键词：氯化钠聚四氟乙烯薄膜制备红外光谱硅衬底

非晶态聚合物主转变弛豫峰与玻璃化转变过程的相关性研究

在线全文

学校读者我要写书评

暂无评论

物理学报 1996年第8期45卷 1359-1365页

作者：李健张烨张声春中国科学院固体物理研究所内耗与固体缺陷开放研究实验室合肥230031 中国科学技术大学结构分析开放研究实验室合肥230026 中山大学材料研究所广州510275

从弛豫理论出发,在不同的时效时间和不同降温速率下,测量了非晶聚合物PVC玻璃化转变过程中与时间参量密切相关的α峰峰温(T_α)的响应关系,得出以下结论:1)玻璃化转变温度(T_g)一般是指非晶态聚合物热平衡态与非平衡态的温度转变点(T_t)... 详细信息

从弛豫理论出发,在不同的时效时间和不同降温速率下,测量了非晶聚合物PVC玻璃化转变过程中与时间参量密切相关的α峰峰温(T_α)的响应关系,得出以下结论:1)玻璃化转变温度(T_g)一般是指非晶态聚合物热平衡态与非平衡态的温度转变点(T_t),是温度变化造成的热弛豫过程的直接结果,而α内耗峰是在动态力学测量过程中得到的聚合物玻璃态与高弹态(橡胶态)的分界点处的力学弛豫过程,表现为动态模量锐变过程,是非晶态聚合物热平衡态下的特征内耗峰.两者都与非晶态结构的存在紧密相关,它们的表观行为取决于非晶聚合物热平衡态下的同一个本征的弛豫时间,但它们的表征是完全不同的两种物理过程.弛豫时间对温度的强烈依赖性造成玻璃化转变过程的存在,而热平衡态的弛豫性质是α内耗峰存在的前提.2)α峰是稳定的力学弛豫峰,其弛豫机制是在热平衡态下独立存在的,但在不同的测量条件下,它的峰参数受到时效敏感区热处理条件的影响,存在着一个过程内耗峰叠加在α峰上.

关键词：非晶态聚合物弛豫理论玻璃化转变

High Power All-solid-state Nd: YVO4 laser and its intracavity SHG

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Lasers 1996年第3期B5卷 205-208页

作者： ZHANG Jian LI Shiqun LI Jiaqiang WU Nianle(Dept. of Modern Applied physics, Beijing 100084, china)WU Xing YANG Huaguang(institute of physics, academia sinica, Beijing 100080, china)Franz Hollinger(Festkoerper-Laser-Institut Berlin GmbH, TU Berlin, D-1 Tsinghua Univ Beijing China

Ｈｉｇｈ　Ｐｏｗｅｒ　Ａｌｌ－Ｓｏｌｉｄ－Ｓｔａｔｅ　Ｎｄ：ＹＶＯ＿４　ｌａｓｅｒ　ａｎｄ　ｉｔｓ　ｉｎｔｒａｃａｖｉｔｙ　ＳＨＧＨｉｇｈＰｏｗｅｒＡｌｌ－Ｓｏｌｉｄ－ＳｔａｔｅＮｄ：ＹＶＯ＿４ｌａｓｅｒａｎｄｉｔｓ... 详细信息

Ｈｉｇｈ　Ｐｏｗｅｒ　Ａｌｌ－Ｓｏｌｉｄ－Ｓｔａｔｅ　Ｎｄ：ＹＶＯ＿４　ｌａｓｅｒ　ａｎｄ　ｉｔｓ　ｉｎｔｒａｃａｖｉｔｙ　ＳＨＧＨｉｇｈＰｏｗｅｒＡｌｌ－Ｓｏｌｉｄ－ＳｔａｔｅＮｄ：ＹＶＯ＿４ｌａｓｅｒａｎｄｉｔｓｉｎｔｒａｃａｖｉｔｙＳＨＧ￥ＺＨ...

关键词： MRBS all-solid-state laser Nd:YVO4 laser