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Containerless solidification of Zr_(41)Ti_(14)Cu_(12.5)Ni_(10)Be_(22.5) glass-forming alloy in drop tube

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Chinese Science Bulletin 2002年第20期47卷 1700-1703页

作者： LI Gong, SUN Liling & WANG WenkuiCollege of Material Sciences and Engineering, Yanshan University, Qinhuangdao 066004, China Center for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100080, China National Microgravit Coll. of Mat. Sci. and Engineering Yanshan University Qinhuangdao 066004 China Center for Condensed Matter Physics Institute of Physics Chinese Academy of Sciences Beijing 100080 China National Microgravity Laboratory Chinese Academy of Sciences Beijing 100080 China

Droplets of Zr41Ti14Cu12.5Ni10Be22.5 glass forming alloys with different sizes are solidified in a drop tube.containerless processing. Glass transition behavior, crystallization kinetics, and the phase evolution during annealing of the Zr41Ti14Cu12.5Ni10Be22.5 glassy spheres are investigated. The experimental results indicate that the apparent activation energy of the glass transition (Eg=435.5 kJ/mol), and the activation energy of the main crystallization reaction (Ep1 = 249.6 kJ/mol) are obviously different from those of bulk glass samples prepared by water quenched (Eg=559.1 kJ/mol and Ep1=192.5 kJ/mol). The difference is discussed in the view point of the atomic configuration of the liquid state of the metallic glass and nucleation mechanism.

关键词： ZrTiCuNiBe alloy containerless processing activation energy drop tube.

MAGNETOSTATIC EQUILIBRIUM OF ISOLATED MAGNETIC FLUX tube

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Science China Mathematics 1989年第11期32卷 1353-1363页

作者：胡文瑞 Institute of Mechanics Academia Sinica Beijing 100080 PRC

In the present paper, an isolated axisymmetric flux tube.is discussed for slender magnetic configuration. The magnetostatic model and the stratified atmospheric model are applied, respectively, to the regions inside and outside the flux tube. The problem is described mathematically by the nonlinear partial differential equations under the nonlinear boundary condition at the free boundary of flux tube. According to the approximation of a small expansive angle, the solutions of series expressions are obtained formally. The model of polytropic plasma is discussed in detail especially. The results show the distributions of thermodynamic quantities and magnetic field extending from the high β region to the low β region, and the flux tube.may be either divergent or convergent according to the pressure difference outside and inside the flux tube.

关键词： solar magnetic field magnetostatics magnetic flux tube.

ASSOCIATION-DNA, A NEW DISCOVERY RELATED TO MALE GERM UNIT IN THE POLLEN tube.OF Camellia sinensis

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Chinese Science Bulletin 1991年第2期36卷 163-166页

作者：莫永胜张玉麟过全生 Department of Biology Wuhan University Wuhan 430072 PRC Division of Basic Courses Zhejiang Agricultural University Hangzhou 310029 PRC

Up to now, male germ units (MGUs)have been found in many angiosperms. This is an important advance in the studies of reproductive biology. However, there is little information on the interaction (the penetration and exchange of substances) between vegetative nucleus (VN) and generative cell (GC) or sperm cells within MGUs. If there exists, what kind of substance Will it be and how will it work, and what physiological function will it have? This is a very important problem which needs to be solved as soon as possible.

关键词： male germ unit association-DNA pollen tube.

Reflection of Shock Wave in PUR Foam From Rigid Wall

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Chinese Science Bulletin 1994年第6期39卷 459-462页

作者：国相杰李仲发俞鸿儒 Institute of Mechanics Academia Sinica Beijing 100080 PRC

Keller proposed that a building, a mechanical installation or a body wrapped bya layer of foam plastics may be an efficient means for protection from damage ofblast wave. However, the practical effect was beyond expectation. For example, agunner wearing the foam plastics-padded waistcoat was injured more seriously by theblast wave from a muzzle. Monti took the foam plastics as homogeneous two-phasemedium and analyzed it with the theory of dusty flow. The obtained results showthat the peak pressure behind the reflected shock wave from rigid wall with foamcoat exceeds obviously that without foam coat under the same condition. Gel’fand,Patz and Weaver made experimental observations by means of shock tube. and veri-

关键词： shock wave foam two-phase flow shock tube.

IMMUNOHISTOCHEMICAL LOCALIZATION OF 5-HT IN AMPHIOXUS

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Chinese Science Bulletin 1991年第4期36卷 329-332页

作者：黄威权方永强苏慧慈齐襄 Department of Histology and Embryology Fourth Military Medical University Xi'an 710033 PRC Third Institute of Oceanography SOA Xiamen 361005 PRC

5-hydroxytriptamine (5-HT) is one of the important bioactive substances. It has not been recorded whether 5-HT is existent in amphioxus. Gerzeli found that there were argentaffin cells located in the digestive tract o... 详细信息

关键词： amphioxus digestive tract 5-HT immunohistochemistry neural tube.