高压物理学报

ZHANG Guan-Ren

1997, 11(3): 163-168 . doi: 10.11858/gywlxb.1997.03.001

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Abstract:
The voids distribution function in ductile metal is derived theoretically in this paper, and verifications of the Fe and Ta recovered samples are made under dynamic loading. Their voids distribution is on the same curve, but the scales of voids number are different. This demonstrates their similarity. On the other band, from Ref. [5], the results of brittle material under static loading, also appear the same property. Thus, the author concludes that it is possible that all materials may have the same similarity. Finally, the prospects of using this property are discussed.

A Study of the Growth Interfaces of Diamond under High Temperature and High Pressure

HAO Zhao-Yin, GAO Chun-Xiao, LUO Wei, ZOU Guang-Tian, CHENG Kai-Jia, CHENG Shu-Yu

1997, 11(3): 169-174 . doi: 10.11858/gywlxb.1997.03.002

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Abstract:
The growth interface of diamond crystal and the catalytic alloy film graphite interface were measured by using a scanning electron microscope and Auger scanning microprobe. The groove structures on the catalytic alloy film surface, the diamond surface and the transition layer have been observed. There exist marked differences in the shapes and relative energies of Auger spectra of carbon atom. The changes in line-shapes and relative energies of these Auger line definitely reflect the differences in the wave functions of the 2s and 2p electrons in carbon atoms, in graphite and diamond crystal, respectively.

Theoretical Calculation for the Hugoniot Curves and Studies on the Effective Two-Body Potential of Helium

YANG Xiang-Dong, WU Bao-Jian, XIE Wen, HU Dong, JING Fu-Qian

1997, 11(3): 175-181 . doi: 10.11858/gywlxb.1997.03.003

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Abstract:
The variational fluid perturbation theory is used to calculate the Hugoniot curves of liquid helium using the exponential-six reference potential. An effective potential which incorporates many-body effects is given by means of comparison of the theoretical and experimental data. This potential is fairly close to the optimum potential given by Nellis et al. Our study shows that when the shock-compression properties for high-temperature and high-density fluid are calculated, interatomic many-body effects are much more important and have the effect of softening the two-body potential.

Chemical Reaction Induced by Steady Shock Wave

FAN Bao-Chun, CUI Dong-Min, CHEN Qi-Feng

1997, 11(3): 182-188 . doi: 10.11858/gywlxb.1997.03.004

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Abstract:
According the under-relaxation Newton-Raphson iteration derived in this paper, chemical reactions induced by steady oblique shock waves were calculated and influences of chemical components, isentropic exponent of chemical product and reaction heat etc on chemical equilibriums were discussed.

A Quasi-One Dimensional Magnetic Hydro-Dynamic Model of Electromagnetic Implosion

LIAO Hai-Dong, HU Xi-Jing

1997, 11(3): 189-196 . doi: 10.11858/gywlxb.1997.03.005

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Abstract:
Assuming that the material density change rate is known, and magnetic diffusion equation is linear and planar, the partial differential equations of the cylindrical one dimensional flow can be reduced to the ordinary differential equations. The motion of the liner under the optimized parameters for the electro-magnetic implosion device is computed by slug model, one-dimension model and quasi-one-dimension model, respectively, and their results are compared.

Shock Compressions of Carbon and Water Mixture

HU Dong, YANG Xiang-Dong, JING Fu-Qian, WANG Yong-Guo, LI Xiao-Chang, SUN Zhu-Mei, DONG Shi, SHI Shang-Chun

1997, 11(3): 197-202 . doi: 10.11858/gywlxb.1997.03.006

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Abstract:
Behavior of shock compression of the mixture of carbon and water are studied by means of two stage light gas gun. It is found that the behavior of the mixture of graphite and water are different from that of the mixture of diamond and water below shock pressure of 19 GPa; when shock pressure is higher than 23 GPa, their Hugoniots comes closer. It shows that most of graphite has transited to diamond. The Hugoniot of the graphite and water mixture at 52.9 GPa behaviors different from that mention above due to the formation of gas products under higher pressures.

Measurements of the Time Resolution for High Speed Streak Camera

YE Shi-Can

1997, 11(3): 203-208 . doi: 10.11858/gywlxb.1997.03.007

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Abstract:
In this paper, the author described the cause to generate time resolution, the importance of the time-resolution measurement in high speed photograph, the work done, and the difficulties encountered. A new method to determine the time resolution is introduced and results are presented, which shows that the time resolution for GSJ camera reaches as high as 8.6 ns with a RMS error of 1 ns.

The Effect of High Pressure on the Defect Structure inside La0.7Sr0.3MnO3 Nanosolids

ZHENG Fan-Lei, SUI Yu, XU Da-Peng, SU Wen-Hui, GUO Ying-Huan, YANG Hua, WANG Yun-Yu

1997, 11(3): 209-214 . doi: 10.11858/gywlxb.1997.03.008

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Abstract:
In this paper, the La0.7Sr0.3MnO3 nanoparticles with average sizes of 40 nm were synthesized by sol-gel method. The La0.7Sr0.3MnO3 nanosolids were prepared by compacting the nanoparticles under high pressures from 0.2 to 4.5 GPa (6 mm1 mm). Positron-lifetime spectra of all samples were measured. Three types of vacancy defects within nanosolids and their changes with pressure were studied. When p1.0 GPa, the three types of vacancy defects are sensitive to pressure; at p1.0 GPa, the number of the microcavity defects with several single vacancies in size increased obviously because of the occurrence of pressure-induced crystallite breaking, this led to the increase of defect density within nanosolids. An abnormal change of defect structure depending on pressure was found.

The Pressure-Temperature Relation for High Pressure Gases with Compressibility Factor Z1

CAO Zhi-Jue, GUO Yu

1997, 11(3): 215-219 . doi: 10.11858/gywlxb.1997.03.009

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Abstract:
Using equation of state and other fundamental formulae in canonical ensemble, we derive a partial differential equation satisfied by high-pressure gases. With this equation it is possible to obtain a new nonlinear differential equation, which gives the pressure-temperature relation for a gas with high pressure in the vicinity of (T0, p0). Following this way, we can avoid computing configuration integrals and improve the previous approach given in Ref.1. The mean error of our results is found to be less than 0.9% for |T|15 K in comparison with those calculated with Redlich-Kwong equation.

Ni-Cd Accumulator and Application in High-Power Supply

YANG Qiong-Song, DAI Guang-Sen, WANG Min-Hong

1997, 11(3): 220-226 . doi: 10.11858/gywlxb.1997.03.010

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Abstract:
This paper introduces the feasibility of the Ni-Cd accumulator to be used in pulse high-power supply. The discharge regularity of the accumulation and the method eliminating memory effect are described. The experimental results obtained from the prototype machine proved that this kind of power supply made of accumulator can reduce the instantaneous load and decrease investments on electrical net and enhance its performance.

Studies on Cylinder Test and JWL Equation of State of Detonation Product for Insensitive High Explosive

YU Chuan, LIU Wen-Han, LI Liang-Zhong, FENG Min-Xian, YANG Shu-Ying, LONG Xin-Ping

1997, 11(3): 227-233 . doi: 10.11858/gywlxb.1997.03.011

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Abstract:
This article reports the results of two kinds of cylinder test of the insensitive high explosive JB-9014 which consists mainly of TATB, with diameter of 25 mm and 50 mm, respectively. By measuring R(t) the expansion history of the TU1 tube driven by detonation products, we have done some comprehensive analysis and 2D numerical simulations for the cylinder tests, to evaluate the ability of doing work and the similarity of cylinder test. By using 2D fluid dynamic numerical simulation, we obtained the parameters of JWL equation of state for JB-9014. The numerical simulation for 2D slipping detonation driven experiment of JB-9014 shows that the parameters of JWL equation of state derived from our experiments and numerical simulations are reliable and with high precision.

The Constitutive Equation of Porous Materials under Shock Wave Loading

SUN Chong-Feng

1997, 11(3): 234-239 . doi: 10.11858/gywlxb.1997.03.012

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Abstract:
This paper modifies the constitutive equation of the porous materials by introducing a new variable v instead of , which describes the occupation ratio of non-zero pressure matrix volume in porous materials. The new equation p＝vF(v, E) solves the problem the p- model encountered when it is applied to partially melt porous materials. The result of the numerical simulation shows that this modification is reasonable and feasible, and is of valuable for numerical simulation to porous materials under shock wave loading.

1997 Vol. 11, No. 3

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