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Constrained Crystal Growth Behaviour under Unidirectional Melt Flow

第十五届全国泌尿外科学术会议

作者： Gao Xu, Sun yh. The department of urology, Changhai Hospital, Shanghai 200433, China.

Introduction and Objective: As the accurate determining early disease spread for prostate cancer is difficult, how to predict the pathologic features before radical prostatectomy become a key question to choose the be...

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Journal of Materials Science & Technology 1996年第2期12卷 156-158页

作者： Liu, S Zhou, yh National Laboratory of Solidification Processing Northwestern Polytechnical University Xi'an 710072 China

Melt flow has an important influence on the microstructure formation of alloys. In this paper the growth behaviour of constrained crystals is systematically studied. It is discovered that the constrained crystals have a quite complicated response to melt flow. It may grow upstream or downstream or keep its growth direction unchanged with the influence of melt flow. Also low growth velocity and high flow velocity favour the formation of spike-like crystal. A new model is suggested to explain these experimental results.

关键词： Crystal growth from melt

Intermolecular [4+3] Cycloaddition of Cyclic Oxyallyl

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Chinese Chemical Letters 1997年第7期8卷 563-564页

作者： Hu, yh.Bai, DL CHINESE ACAD SCI SHANGHAI INST MAT MEDSHANGHAI 200031PEOPLES R CHINA

The [4+3] cycloaddition of the 6-substituted-2-chlorocyclohexanone and furans under the Fohlish conditions (Et3N in CF3CH2OH) has been accomplished to give tricyclic cycloadducts with good yields.

关键词： KBr IR cm MS MHz Intermolecular Cycloaddition of Cyclic Oxyallyl

Total Synthesis of dl-Ligustiphenol

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Chinese Chemical Letters 1996年第10期7卷 896-897页

作者： Huang, yh.Yu, DQ CHINESE ACAD MED SCI INST MAT MEDBEIJING 100050PEOPLES R CHINA BEIJING UNION MED COLL BEIJING 100050PEOPLES R CHINA

----(-)S-Ligustiphenol is a new sesquiterpene compound with antiinflammatory and immunosuppressive activities. The total synthesis of its racemate was carried out by a six-step reaction sequence including bromination of aldehyde, iodination of m-cresol, protection of phenolic hydroxyl, Grignard reaction,aldol condensation, etc. The target compound was characterized by comparing its H-1 NMR,MS and IR spectra with natural (-) ligustiphenol.

关键词： Total Synthesis of dl-Ligustiphenol

Dissolution-facilitating Dislocation Emission, Motion andInitiation of SCC in 310 Stainless Steel

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Journal of Materials Science & Technology 1997年第6期13卷 483-486页

作者： Huang, yh.Chen, QZ Chu, WY Univ Sci & Technol Beijing Dept Mat Phys Beijing 100083 Peoples R China

Using a special constant deflection device, the in situ TEM observations of dislocation emission, motion and the initiation of nanocrack in 310 stainless steel in water were carried out. The results show that SCC in thin foil specimen of 310 stainless steel can occur in water. A nanocrack initiated in the DFZ or at the blunt crack tip in corrosion solution after dislocation emission, multiplication and motion, which were induced by the localized anodic dissolution, reached a critical condition. The nanocrack propagated by a cleavage mode because of the influence of the corrosion solution.

关键词： Stainless steel

Bearing Wear Resistance of Monotectoid Zn-Al Based Alloy (ZA-35)

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Journal of Materials Science & Technology 1995年第2期11卷 109-113页

作者： ZHU, yh.YAN, B HUANG, W TONGJI UNIV DEPT MAT SCI & ENGNSHANGHAI 200092PEOPLES R CHINA

Based on the fundamental investigations of ageing characteristics and microstructures, performance properties of monotectoid Zn-Al based alloy ZnAl35Cu3Si2 (in wt-%) named ZA-35 were studied. The test results showed the ZA-35 alloy displayed better bearing wear resistance than copper bronze and lower coefficient of thermal expansion than other Zn-Al alloys. These excellent performance properties have been verified by practical applications.

关键词： Zinc alloys

A VARIATIONAL PRINCIPLE ON MAGNETOELASTIC INTERACTION OF FERROMAGNETIC THIN PLATES

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Acta Mechanica Solida Sinica 1997年第1期10卷 1-10页

作者： Zhou, yh.Zheng, XJ LANZHOU UNIV DEPT MECHGANSU 730000PEOPLES R CHINA

The key to revealing the behaviors of magnetoelastic interaction is how to express the magnetic forces applying on a ferromagnetic elastic body. In this paper, a functional for a ferromagnetic thin plate in magnetic fields is proposed by taking the summation of the magnetic energy of the magnetic system and the strain energy of the elastic plates. We present a variational principle for the problem by choosing the variations of magnetic potential and deflection as independent variates each other. Based on the principle, not only are the simultaneous governing equations for magnetic fields and deformation of structures deduced, but also a general expression of magnetic force acting on the plates is gained, which makes it possible to commonly simulate the distinct two experiments of magnetoelastic interaction in a theoretical model. Thus, it can be used to theoretical prediction of the magnetoelastic interaction of ferromagnetic plates in a complex environment of applied magnetic fields.

关键词： magnetoelastic interaction variational principle expression of magnetic force ferromagnetic thin plates

Investigation on the Microstructure Homogenization in a TiAl Based Alloy Prepared by Elemental Powder Metallurgy

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Journal of Materials Science & Technology 1999年第6期15卷 527-530页

作者： Liu, Y Huang, BY He, yh.Wang, JN Cent S Univ Natl Key Lab Powder Met Changsha 410083 Hunan Peoples R China

A Ti-48Al (at. pet) alloy prepared by elemental powder metallurgy (EPM) has been heat treated under various conditions. Through optical and scanning electronic microscopy, EDAX, XRD analysis, and DTA, it was shown that the hot pressed microstructure consisted of alpha(2)-Ti3Al and TiAl phases. The alpha(2)-Ti3Al phase was island-like, and had a high stability and heredity in subsequent heat treatments. The supersaturation of Al in the island-like alpha-Ti3Al phase strongly influenced the transformation of alpha(or alpha(2)) to alpha(2)/gamma lamellar colonies. After a heat treatment at 1380 degrees C for 0.5 h and 1000 degrees C for 8 h, a fully lamellar microstructure with a colony size of 50 mu m was obtained. This result indicates that a homogeneous composition and an equilibrium microstructure in EPM TiAl-base alloys can only be obtained after heat treatment at temperatures above alpha transus temperature (T-alpha).

关键词： Titanium alloys

Remarks on the nonlinear Schrodinger equations in plasma

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Chinese Science Bulletin 1997年第22期42卷 1875-1877页

作者： Guo, BL Wu, yh Inst Appl Phys & Computat Math Beijing 100088 Peoples R China

CONSIDER the following nonlinear Schrodinger equation: （SP）{iΔφt+Δ2φ+β(|φ|2pφ)=0,x∈R2,t>0, （1,1） φ|i=0=φ0（x）, （1,2）where p>0, β∈R are constants, φ0∈H3 （R2）. For the problem arising from nonline... 详细信息

关键词： Schrodinger equations existence blow-up.