高压物理学报

The Structure Assembly of High Tc Superconductor

JIN Chang-Qing

2003, 17(3): 161-168 . doi: 10.11858/gywlxb.2003.03.001

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Abstract:
A new structure assembly method is proposed to describe the high Tc superconductor materials. Using this method, the main crystalline structures of the high Tc superconductors were derived in the language of infinite layer in Cu-O perovskite. Furthermore, a three digit nomenclature has been adopted to catalog the structures of the high Tc superconductors.

Spectroscopic Studies of Epoxypropane Ignition

HU Dong, YUAN Chang-Ying, LI Ping, CHENG Xin-Lu, LIU Jin-Chao, SUN Zhu-Mei

2003, 17(3): 169-172 . doi: 10.11858/gywlxb.2003.03.002

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Abstract:
A new spectroscopic technique is introduced to measure the delay time of the shock ignition of epoxypropane. Intermediate product of the most early emergence for the loaded fuel is determined at first using spectrometer, because the intermediate product of O for epoxypropane after shock ignition is always emerged early. Then the monochrometer is adjusted to 436.8 nm (or 395.46 nm, 394.7 nm) wavelength of O, and the arrival time of shock wave is measured by gauge. The delay time of shock ignition for epoxypropane is determined. The delay time determined by the method is closer than that of using photo-electric diode whose peak wavelength is about 800 nm. The measured results show that the emergence times of intermediate product of O for epoxypropane after shock ignition are different, and radiation intensities for the radicals are also different. The emergence times for O, CH2O, C2, CH, CH3O, CO2, H2O radicals are obtained after the shock wave enters into the epoxypropane. Oxygen atoms are always presented first.

Study of Equation of State of the Dense Fluid He+H2 Mixtures

CHEN Qi-Feng, CAI Ling-Cang, CHEN Dong-Quan, JING Fu-Qian, ZHAO Xian-Geng

2003, 17(3): 173-179 . doi: 10.11858/gywlxb.2003.03.003

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Abstract:
The mixing rule and the variational perturbation theory together with van der Waals one-fluid model have been used to study the equation of state of the dense fluid He+H2 mixtures with different H2∶He compositions in this work. The first-order quantum correction is included. To test the model and computational code, the isotherm of the fluid He+H2 mixtures at 300 K is calculated by using the existing -exp-6 optimization potential parameters. The calculated isotherm for the fluid He+H2 mixtures is in agreement with the experimental data and molecular dynamics simulations. Then the equation of state of the fluid He+H2 mixtures with different He∶H2 (He∶H2=1∶1, 1∶3, 3∶1) compositions have been further investigated in the pressure range 0~60 GPa and temperature in the range 50~7 000 K. Comparisons of the present results with Monte-Carlo simulations indicate that the quantum corrections for the calculation of the thermodynamic properties become significant at lower temperatures.

A Comparative Study of the Evolution of R-T Instability in Two and Three Dimensions

XU Li, SUN Jin-Shan

2003, 17(3): 180-186 . doi: 10.11858/gywlxb.2003.03.004

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Abstract:
Rayleigh-Taylor (R-T) instability at the interface of two different fluids is studied analytically by using perturbation method. We analyze and compare the linear and nonlinear growth of R-T instability in two (2D) and three (3D) dimensions. The obtained conclusion includes, (1) linear growth of the instability in 3D is faster than that in 2D, and growing exponential of identical initial perturbation wavelength in one dimension is affected by that in others, (2) perturbation growth profile of R-T instability in 3D is different from that in 2D after allowing for nonlinear evolution.

Synthesis and Characterization of KNb1-xTixO3- Solid Solutions

XIANG Jun, LI Li-Ping

2003, 17(3): 187-192 . doi: 10.11858/gywlxb.2003.03.005

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Abstract:
KNb1-xTixO3- (x=0～0.40) solid solutions were synthesized under high temperature and high pressure for the first time. The structural characteristics and ionic conductivity of KNb1-xTixO3- solid solutions were investigated by XRD, TG-DTA, Raman and impedance spectroscopy techniques. XRD results showed that Ti-doping resulted in structural transformation, the samples of x0.15 have orthorhombic perovskite structure, but the samples of x0.15 are single tetragonal phase. With the increase of doping amount, the cell volume decrease. The Raman spectra at different temperatures and DTA curve indicate that the structure of the solid solutions had been changed, Ti-doping broadens tetragonal phase zone, and curie temperature decrease with the increase of dopant content. The ionic conductivity of the samples measured by impedance spectroscopy shows that in all the samples the ions are main carriers. KNb0.85Ti0.15O2.925 has the highest conductivity of 5.610-3 Scm-1 at 800 ℃. A marked curvature at T=630 ℃ has been observed in the Arrhenius plot of the bulk conductivity. The activation energy below 630 ℃ is lower than that above 630 ℃, and the cause is discussed.

Experimental Studies on the Multi-Point Initiation of the Insensitive Explosive JB9014

WEN Shang-Gang, ZHAO Feng, SUN Cheng-Wei

2003, 17(3): 193-198 . doi: 10.11858/gywlxb.2003.03.006

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Abstract:
By means of SVR electrical camera and streak camera, the waveform of detonation wave front on the bottom of insensitive explosive JB9014 are recorded in multi-point initiation experiments, and the experimental results are analyzed.

The Determination of Melting-Point and Debye Characteristic Temperature of Nano-Diamond from X-Ray Diffraction Intensities

WEN Chao, SUN De-Yu, GUAN Jin-Qing, LIU Xiao-Xin, LI Xun, ZHOU Gang, LIN Jun-De, JIN Zhi-Hao

2003, 17(3): 199-203 . doi: 10.11858/gywlxb.2003.03.007

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Abstract:
The melting-point of nano-diamond was reported in this paper. The Debye characteristic temperature of nano-diamond was calculated based on X-ray diffraction intensities by the methods introduced by LU Xue-Shan and LIANG Jing-Kui. Its Debye characteristic temperature is 411.7 K, which is about one-fifth of the Debye characteristic temperature of bulk diamond single crystal synthesized under high temperature and high-pressure condition. The melting point of nano-diamond is 2 070 K calculated with Lindemann's formula. The atom vibration amplitude, which deflected balance position, increases two times or more. This leads to the increasing of activity of nano-diamond.

Experimental Investigation of Shaped Charge with Large Cone Angle

TAN Duo-Wang, SUN Cheng-Wei, ZHAO Ji-Bo, ZHANG Ke-Ming, XIE Pan-Hai

2003, 17(3): 204-208 . doi: 10.11858/gywlxb.2003.03.008

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Abstract:
By means of X-ray flash radiographs, the jet formation and penetration of two types of shaped charge with large cone angle were investigated, and compared with that of the jet of shaped charge with small cone angle (42). The experimental results show that (1) the jet of shaped charge with large cone angle is characterized by a lower jet tip velocity and a very large portion of the liner mass, and (2) at a long standoff the depth of penetration in steel target is small, but the diameter of hole is large.

Shock-Activating and Sintering of Hydroxyapatite Agglomerate

LIAO Qi-Long, YANG Shi-Yuan, CAI Ling-Cang, ZHENG Chang-Qiong

2003, 17(3): 209-213 . doi: 10.11858/gywlxb.2003.03.009

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Abstract:
Hydroxyapatite (HA) is an effective material used in bone prostheses. The activating and sintering characteristics of hydroxyapatite agglomerate treated by shock wave were studied. Using XRD and SEM the grain size refinement, homogenization and lattice deformation were observed in shocked HA powders, which can promote sintering of HA ceramics. The extra energy stored in shocked powders will be released during sintering process. The temperature of maximum shrink rate of shocked sample is about 70 lower than that of unshocked one. The strength and density of HA ceramics from the shocked sample can be enhanced. HA ceramics with high strength used for artificial bone materials can be made with the shock-activating method.

Comments on the Unjustification of CJ and ZND Model in Detonation

HU Shao-Ming, LI Chen-Fang

2003, 17(3): 214-219 . doi: 10.11858/gywlxb.2003.03.010

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Abstract:
The essential change caused by sudden heat energy release in a detonation process is not fully considered by the CJ and ZND model. In these classical detonation theories, the entropy at the final detonation point is the lowest one among all possible states, and the probability is the lowest. The final detonation point shall be decided by the thermodynamics, which can not be achieved through the ZND model. The fluid mechanics and thermodynamics laws must be satisfied in a goog detonation model.

Two Approximate Models for Describing Solid-Liquid Phase Transition of Mixtures

RAN Xian-Wen, TANG Wen-Hui

2003, 17(3): 220-225 . doi: 10.11858/gywlxb.2003.03.011

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Abstract:
Two models, Mixing phase model and Equivalent material model, were developed based on a mixing principle. By applying them to 304 steel, the pressure-temperature curve was calculated. It was shown that the calculated curve was in agreement with that calculated directly using material parameters of 304 steel.

Research on Raman Spectra of Calcite at Pressure of 0.1~800 MPa

ZHAO Jin, ZHENG Hai-Fei

2003, 17(3): 226-229 . doi: 10.11858/gywlxb.2003.03.012

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Abstract:
This paper investigates the reliability of calcite as a pressure gauge for the hydrothermal diamond anvil cell (HDAC) by the experiment at the pressure of 0.1~800 MPa and the temperature of 26 ℃, and defines the relation between the pressure and the Raman peak position of calcite in ambient temperature. The result shows that calcite is stable at the experimental pressure, and the intensity of its 1 085 cm-1 Raman peak is two times greater than that of the 464 cm-1 Raman peak of quartz, calcite is reliable as a pressure gauge for the hydrothermal diamond anvil cell. The relation between the system pressure and peak position of calcite (1 085 cm-1) is given as following: p(MPa)=192(p－1 085)－21.8, 1 085 cm-1p1 090 cm-1.

Function Realation between Nuclear Exploding Yield and Dilating Velocity of Mushroom Cloud

JIN Liang-An, WANG Xiao-Tong, ZHANG Ming-Hu, YANG Chang-Qing

2003, 17(3): 230-234 . doi: 10.11858/gywlxb.2003.03.013

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Abstract:
The lots of data of mushroom cloud width were analyzed by numerical method. The new concept, dilating velocity of mushroom cloud of nuclear exploding, was put forward. The function relation between the dilating velocity and the nuclear exploding yield was set up. The new detecting method based on this function relation was established. It was tested and verified by the data of nuclear tests that the relative errors of the detecting results of this method are not exceeding 3%.

Configurational Design for Centralized Control System of Hexa-Orientation Press

SUN Yue, BI Yan, DONG Yue, LUO Xiang-Jie, DING Li-Ye, YANG Xiang-Dong

2003, 17(3): 235-240 . doi: 10.11858/gywlxb.2003.03.014

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Abstract:
The control system of a hexa-orientation press is consisted of measurement and control units for high pressure and high temperature. By applying the configuration software, the precision of tracking control and temperature and pressure maintainenance have reached or exceeded original projects under the guarantee with remarkably shortening period of design and saving invest on project. Through this approach, the direct comparison and auto-convert of inner temperature vs. heating power and inner vs. outer pressure of the load bulk were realized; the locale data were analyzed with online database after the event; and remote device controlling and teledata accessing are convenient to realize.

2003 Vol. 17, No. 3

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