1995 Vol. 9, No. 1

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Breakdown of Ferroelectric Ceramics under Shock Loading
ZHANG Guan-Ren
1995, 9(1): 1-4 . doi: 10.11858/gywlxb.1995.01.001
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Abstract:
By considering the conducting crack as the result of electrical break down, this paper derives a storage energy formula when there is a crack in contact with and perpendicular to a surface of the ferroelectric block. Then the driving energy per unit area of the crack developing surface is deduced. W...
Conversion Behavior of Various Hexagonal Boron Nitrides to Cubic Boron Nitride
ZHOU Yan-Ping, YAN Xue-Wei, DU Sen-Lin, MA Xian-Feng, CUI Shuo-Jing, ZHAO Wei
1995, 9(1): 5-12 . doi: 10.11858/gywlxb.1995.01.002
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Abstract:
Cubic boron nitride (cBN) is synthesized from seven kinds of the hexagonal boronnitride (hBN) under a pressure of 4.6 GPa and a temperature of 1 600 ℃ with catalyst by using a cubic anvil press. The contrast to the standard curve is made in the present work, and the conversion yields of different ki...
Approximants C4 and C5 of the Decagonal Quasicrystal in Al70Co15Ni10Tb5 Alloy Obtained by Quenching from Melting State under High Static Pressure
YU Ri-Cheng, XU Da-Peng, SU Wen-Hui, PANG Xin-Yan
1995, 9(1): 13-19 . doi: 10.11858/gywlxb.1995.01.003
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Abstract:
Two new approximants of the decagonal quasicrystal were found in the Al70Co15Ni10Tb5 alloy, which was prepared by quenching from melting state under high static pressure (7.0 GPa). The lattice parameters of the approximants were =1.38 nm, b=1.6 nm, c=2.0 nm (C4, B-type orthorhombic crystalline phase...
Experimental Studies of the Thermal Shock Wave Produced in the Flat Plate Targets Bombarded by Electron Beam on 'Flash-Ⅱ'
PENG Chang-Xian, WANG Zhan-Jiang, WANG Wei, WANG Zheng, XU Yong-Liang, CHENG Gui-Gan
1995, 9(1): 20-28 . doi: 10.11858/gywlxb.1995.01.004
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Abstract:
The thermal shock wave is an important mechanic phenomenon of the material response produced in the target material bombarded by electron beam. In this paper, the experimental studies of the thermal shock wave produced in the flat plate targets bombarded by electron beam on FLASH Ⅱ equipment during ...
Synthesis of T1-System Monophase Superconductors under Oxygen Pressure and Its High Pressure Effect
LIU Zhen-Xing, MENG Xian-Ren, SHEN De-Yuan, LIN Ming-Zhu, TU Qing-Yun, LIN Zhen-Jin, SANG Li-Hua, PENG Zhi-Qiang
1995, 9(1): 29-33 . doi: 10.11858/gywlxb.1995.01.005
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Abstract:
Effect of oxygen pressure on the preparation of TI-system superconductors at pressure 0~3 MPa is reported. Under the same sintering temperature and in the same duration, the phase fractions and Tc as well as the weight loss are found to depend directly on the oxygen pressure. When the oxygen pressur...
Effect of Structure Inhomogeneity of the Surface Lattice on Diamond Morphology
ZHANG Shu-Da, ZHU Yao-Hua
1995, 9(1): 34-38 . doi: 10.11858/gywlxb.1995.01.006
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Abstract:
According to W. D. Harkins' theory we calculated the surface energy of some diamond planes as: (100)=9.068 J/m2, (110)=6.412 J/m2, (111)=15.706 J/m2 and b(111)=5.235 J/m2. If the final form of diamond could be accounted for by Gibbe-Wulff's crystal growth taw, the probability of the appearance of {1...
Microstructure and Pressure Dependence of Resistivity in Alloy FeCuNbMSiB (M=Nb, V, Mo) with Nanophase Crystallization
SU Fang, XIE-Bin
1995, 9(1): 39-48 . doi: 10.11858/gywlxb.1995.01.007
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Abstract:
The results on X-ray diffraction and transmission electron microscope indicated that crystallized nanophase was -Fe(Si) solid solution in amorphous FeCuNbMSiB (M=Nb, V, Mo) alloys after annealing at 540 ℃ for 20 min. Graininess of -Fe(Si) was 10~20 nm. Besides, their resistivity under atmospheric pr...
Effects of the Cluster Model for Diamond (111) Plane on the Interactive Potential between Methyl and the Surface
LIU Bo, QIAN Xing-Zhong, DAI Zhen-Wen, PAN Shou-Fu
1995, 9(1): 49-52 . doi: 10.11858/gywlxb.1995.01.008
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Abstract:
The effects of the cluster model for diamond (111) plane on the interactive potential between methyl and the surface were investigated theoretically and computationally. We concluded that a small cluster model with fewer layers is nearly as reasonable as a larger one with more layers, the error in r...
Morphology and Thermal Stability of Shock Synthesized wBN Powders
TAN Hua, HAN Jun-Wan, HE Hong-Liang, WANG Xiao-Jiang
1995, 9(1): 53-58 . doi: 10.11858/gywlxb.1995.01.009
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Abstract:
We reported some main features of shock synthesized wBN ceramic powders by its morphology, specific surface area, microdensity, crystallite size as well as the B to N atomic ratio. These will reflect, from anoth side, the unique high defect density which exists in the wBN crystals. We also analyzed ...
Numerical Simulation of the Radiance in Shock Temperature Measurement
LIN Hua-Ling, YU Wan-Rui
1995, 9(1): 59-68 . doi: 10.11858/gywlxb.1995.01.010
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Abstract:
Considering the effects of the window opacity, the interface emissivity and the heat conduction on the radiance in shock temperature measurements, we present that the increase of opacity under shock compression is an important factor that influences the time dependence of the radiance. Using the equ...
A Pressure-Induced Phase Transition Study of -BaB2O4 Crystal by X-Ray Diffraction
GU Hui-Cheng, CHEN Liang-Chen, LI Feng-Ying, CHE Rong-Zheng, CHEN Hong, WANG Ji-Fang, LIN Yuan-Kun, LAN Guo-Xiang
1995, 9(1): 69-73 . doi: 10.11858/gywlxb.1995.01.011
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Abstract:
Phase transitions of -BaB2O4 crystal have been studied by using X-ray powder diffraction technique with a diamond anvil cell (DAC) at high pressure up to 17.6 GPa. According to the X-ray diffraction results, -BaB2O4 crystal undergoes three pressure-induced phase transitions neat 2.2 GPa, 5.3 GPa, 11...
Study of Intermediate Layers between Diamond Film and Non-Diamond Substrates
YANG Guo-Wei, MAO You-De
1995, 9(1): 74-80 . doi: 10.11858/gywlxb.1995.01.012
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Abstract:
The intermediate layers between diamond films and non-diamond substrates. in diamond film system grown with low pressure vapor phase methods, have been studied by interface energy theory. We have put forward the theoretical mechanism of the existence of intermediate layers, and explained some experi...