高压物理学报

The Long Distance Propagation of Detonation Waves in the Spherical Shell Charge

FANG Qing, WEI Yu-Zhang, ZHAO Yu-Hua, LONG Jian-Hua, ZHANG Ke-Ming, PU Zheng-Mei

2000, 14(1): 1-5 . doi: 10.11858/gywlxb.2000.01.001

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Abstract:
The experiment of the long distance diffraction propagation of detonation waves in a spherical shell of plastic bonded HMX/TATB=87/7 explosive has been conducted. A simple approximate calculation method is given, which can exactly reconstruct the long distance non-ideal propagation of detonation waves in the spherical shell of the charge.

Equation of State of Detonation Product (Ⅱ)－Does ZND Theory of Detonation Fail? (B)

LI Yin-Cheng

2000, 14(1): 6-15 . doi: 10.11858/gywlxb.2000.01.002

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Abstract:
Another test is operated for testing the ZND theory of detonation with the Jones relation in this paper. It requires no knowledge of the equation of state other than knowing the fact that it surely exists. Due to only little carelessness, using this method American scientists had drawn the conclusion that the ZND theory of detonation fails. More careful test using this method is operated by the author and a new conclusion is obtained that the ZND theory is true.

Influence of Consolidated Pressure upon Phase Transition and Ionic Conductivity of Nanophase PbF2

LIU Jin-Fang, WU Xi-Jun, XU Guo-Liang, ZHOU Yu-Song, LI Bing-Han

2000, 14(1): 16-21 . doi: 10.11858/gywlxb.2000.01.003

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Abstract:
The bulk samples with a diameter of 10 mm and thickness of 1 to 2 mm of nanophase PbF2 were prepared by using an inert gas evaporation and in situ consolidating method under the pressure range from 0.3 GPa to 1.8 GPa. The average grain size and phase identification were studied by X-ray diffraction. The ionic conductivity was measured precisely by means of the complex impedance spectra. The results show that the phase content of -PbF2 enhances from 21.6% to 94.5% when the consolidated pressure increases from 0.3 GPa to 1.8 GPa. The ionic conductivity of nanophase PbF2 is about one order of magnitude higher than that of coarse-grain -PbF2, and is approximately equal to that of coarse-grain -PbF2.

Multi-Stage Detonation System－A New Loading Technology for Studying Hypervelocity Impact

WEN Shang-Gang, SUN Cheng-Wei, ZHAO Feng, LI Qing-Zhong

2000, 14(1): 22-27 . doi: 10.11858/gywlxb.2000.01.004

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Abstract:
The problem of accelerating metallic flyers to ultra high speed by multi-stage detonation system is analyzed. The results of theoretical analysis, numerical simulation and experiments show that the hypervelocity flyers can be obtained by this technology. The set-up of this driving system is of advantages in simple structure, convenient operation. It can be used as a new loading technology for the study on hypervelocity impact.

Electrical Properties, Equations of State and Phase Transitions in Hg1-xCdxTe at High Pressure

BAO Zhong-Xing, CHU Jun-Hao, LIU Cui-Xia, GU Hui-Cheng, LIU Ke-Yue, LI Biao, WANG Jin-Yi

2000, 14(1): 28-32 . doi: 10.11858/gywlxb.2000.01.005

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Abstract:
The resistance-pressure and capacitance-pressure relationships for Hg1-xCdxTe (x=0.19, 0.22) at room temperature at pressures up to 20 GPa have been studied in a diamond anvil cell using resistance and capacitance measurements established by us. The experimental results show that Hg1-xCdxTe (x=0.19, 0.22) undergo two electronic structure transitions at about 0.7～1.8 GPa, 8.6 GPa and 1.6 GPa, 8.3 GPa, respectively, and two crystal structure transitions at about 2 GPa, above 8.6 GPa and about 1.6 GPa, above 8.3 GPa, respectively. In the present work, the p-V relationship for Hg1-xCdxTe (x=0.19, 0.22) at room temperature and up to 4.5 GPa has been studied using the piston-cylinder type measurement device for the p-V relationship. The experimental results indicate that the phase transition in Hg1-xCdxTe (x=0.19, 0.22) occurs at about 2.1 GPa. Its equations of state before and after the phase transition have been given.

Phase Transition and Diamond Synthesis of Carbon Nanotubes under High Pressure and High Temperature

CAO Li-Min, ZHANG Ming, ZHANG Xiang-Yi, GAO Chun-Xiao, ZHOU Zhen-Hua, ZHANG Jun, DAI Dao-Yang, SUN Li-Ling, WANG Wen-Kui

2000, 14(1): 33-36 . doi: 10.11858/gywlxb.2000.01.006

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Abstract:
The phase transition of carbon nanotubes under high pressure and high temperature has been investigated by transmission electron microscope and scanning electron microscope. It is found that the nanotubes are unstable under high pressure and high temperature. When being annealed at the temperature range of 770 ℃ and 950 ℃ under 5.5 GPa, the carbon nanotubes will transform into carbon onions. The diamond is synthesized under the conditions of 1 000 ℃ and 5.0 GPa.The mechanism of the phase transition of carbon nanotubes is well discussed.

The Synthesis of Perovskites Eu1-xKxTiO3 (x=0.2, 0.32) with Mixed Valence in A-Site under High Pressure and Temperature

SONG Xiao-Yu, MIAO Ji-Peng, LI Li-Ping, SU Wen-Hui

2000, 14(1): 37-41 . doi: 10.11858/gywlxb.2000.01.007

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Abstract:
The perovskite oxides Eu1-xKxTiO3 (x=0.2 and 0.32) were synthesized under 4.0 GPa and at 1 090 ℃ with the starting materials TiO2 and Eu2O3. XRD measurements show that the samples are cubic. 151Eu Mossbauer spectra exhibits two peaks at ca. 0 and -13 mm/s, which suggests that Eu ions are in mixed valence of +2 and +3. Only one signal with linewidth 3 140 Guss and g=2.00 is observed within the range of 480 to 6 480 G. The absence of the signals associated with Ti3+ and A-site deficiency indicates that Ti ions is Ti4+. In the process of solid state reaction, Eu3+ ions are easier reduced than Ti4+.

Fractional Diffusion Equation for Anomalous Transport Phenomena

ZENG Qiu-Hua, LI Hou-Qiang, LIU De

2000, 14(1): 42-46 . doi: 10.11858/gywlxb.2000.01.008

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Abstract:
We derive the standard diffusion equation from the continuity equation and by discussing the defectiveness of earlier proposed equations. We get the generalized fractional diffusion equation for anomalous transport.

Researches on Strong Detonation of High Explosives

ZHAO Feng, SUN Cheng-Wei, WEN Shang-Gang, ZHANG Ke-Ming, TAN Duo-Wang

2000, 14(1): 47-53 . doi: 10.11858/gywlxb.2000.01.009

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Abstract:
The speed of strong detonation and its driving abilities in multiple stage explosive/flyer system have been studied by both analysis and experiments. The wedge test method is employed to record the detonation front's track for both TNT/RDX (40/60) and JO-9159 explosives. The abilities of strongly detonating explosive slab in driving metallic flyers to high speed are shown in our calculation model. Calculated results agree with experimental results. The performances of strong detonation are illustrated.

Numerical Simulation of X-Rays for Electro-Magnetically Implosion Experiments

HU Xi-Jing, LIU Gui-Xian, LIAO Hai-Dong

2000, 14(1): 54-61 . doi: 10.11858/gywlxb.2000.01.010

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Abstract:
The paper describes one-dimensional simulation of radiation magneto-hydrodynamics (RMHD) (3T) for X-ray calculation of electro-magnetic implosion. The set of RMHD equations is solved with use of split tricks to avoid possible numerical instabilities due to much coupling in solving the set of highly nonlinear equations. Implicit algorithm is used to avoid small time step limitations. Newton-Raphson iteration is used to solve the set of linear algebra equations. Some special algorithms are used such as average with weight; initial value formula for iteration; setting of virtual mesh as well as automatically adjusting of time step and so on. Finally, the paper presents a computer result of an experimental model from Pegasus 1, which gets X-ray energy 15 J and power 16 GW.

Shock Wave Equation of State and Shock-Induced Melting of Melanterite

GONG Zi-Zheng, ANDERSON W W, BI Yan, JING Fu-Qian, HUO Hui, TAN Hua

2000, 14(1): 62-69 . doi: 10.11858/gywlxb.2000.01.011

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Abstract:
Shock compression experiments were conducted on melanterite samples with an initial density of 1.714 g/cm3 up to 100 GPa. The experimental data can be divided into a low-pressure region consisting of a partially molten state, and a completely liquid state at high-pressure. The shock velocity D is a linear function of the particle velocity u in these two regimes: D=0.59+2.06u for u3.12 km/s and D=3.18+1.223u for u3.12 km/s. K0S and K0S, the zero pressure adiabatic bulk modulus and its first pressure derivative of Birch-Murnaghan EOS (isentrope), are obtained in terms of shock Hugoniot data by using the Eulerian finite strain theory. Under the assumption =3.12(0/), then for the low pressure phase (0=1.898 g/cm3), K0S=3.72 GPa and K0S=4. We find 0=1.60 g/cm3, K0S=3.28 GPa and K0S=10.5 for the high pressure phase (liquid state), with a STP melting energy of 80 J/g and =1.46(0/). The melting curve of melanterite is determined according to Lindemann's law and can be approximately described as: pm(GPa) =0.159(Tm(K)/1000)6.3371+0.69.

Condensed Structure Transformation of HDPE under Shock Pressure

LI Peng, HUANG Rui, LI Liang-Bin, CAI Bi-Hua, FAN Wu-Yi, LIU Fu-Sheng, ZHANG Qing-Fu, SHI Shang-Chun

2000, 14(1): 70-74 . doi: 10.11858/gywlxb.2000.01.012

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Abstract:
In this paper, shock pressed HDPE samples was retrieved and investigated to reveal the effect of shock wave on its crystalline structure and melting process. It is found that shock wave mainly changes the crystallite size and orientation, but has little effect on its lattice structure. The different thermal behavior may be explained based on the structural changes.

Methods of Absolute Measurement of Equation-of-State in Laser Driving High Pressure Experiments

HUANG Xiu-Guang, GU Yuan

2000, 14(1): 75-80 . doi: 10.11858/gywlxb.2000.01.013

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Abstract:
This paper introduces this technique of side-on radiography and flyer three-step-target. The principles and main experimental results of using them to carry out absolute measurement of equation-of-state in laser driving high pressure experiments are also presented.Moreover some discussions are given.

2000 Vol. 14, No. 1

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