高压物理学报

Shock Temperature Measurement for Metals－Influences of a Gap Interface between the Driver Plate and the Metal Film Sample on the Shock Temperature Measurement by Using Radiometry

TAN Hua

1999, 13(3): 161-168 . doi: 10.11858/gywlxb.1999.03.001

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Abstract:
Radiometry is one of the most commonly used techniques in shock temperature measurement for metals. In this paper, we investigated the thermal relaxation history at the sample/window interface for a widely used four-layer target-sample configuration of the metal drive/gap/metal film/transparent window system, and its influence to shock temperature measurement of metals. Although there does not exist a universal analytical solution for the thermal conduction equation of such a four-layer model, an analytical approximation solution does exist, which indicates that the thermal relaxation at the sample/window interface following the shock compression is closely related with the dimension of the gap. If the width of the gap can be compared with the thickness of the film, a sharp peak will appear at the initial of the step-like temperature profile of the sample/window interface, the height and the width of the peak are closely connected with the dimension of the gap. On the other hand, if the thickness of the metal film is much greater than that of the gap, however, a stepped temperature interface with a flat top will appear. Necessary conditions for which a reasonable target-sample assembly should meet with are also discussed.

Cubic Boron Nitride Crystal-Diamond Film Heterjunction p-n Diode

ZHANG Tie-Chen, GAO Chun-Xiao, WANG Cheng-Xin, JI Yan-Ju, ZOU Guang-Tian

1999, 13(3): 169-172 . doi: 10.11858/gywlxb.1999.03.002

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Abstract:
In this paper, B doped P type diamond film was grown on Si doped N type cubic boron nitride (cBN) flaky crystal by means of hot filament CVD method. A heterjunction p-n diode was fabricated. The electrical test shows that it has high rectification efficiency.

Effects of High Pressure and Thermal Treatments on Photoluminescence Efficiency of CNx Film

ZHAO Jing, CHE Rong-Zheng, XU Ji-Ren, KANG Ning, LIU Jing, YANG Yang

1999, 13(3): 173-177 . doi: 10.11858/gywlxb.1999.03.003

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Abstract:
Laser induced photoluminescence of carbon nitride films was measured under high pressures up to 24 GPa and after thermal treatment at different temperatures. The experimental results show that both effects of thermal treatment and high pressure induce the decrease of photoluminescence strength, but the former is non-recoverable while the later recoverable after release of pressure to ambient atmosphere. The two kinds of quenching of photoluminescence are attributed to different mechanism. Our results supply a further experimental evidence to support the active PL center model of the undistorted aromatic sp2 cluster with various size and embedded in sp3 bond matrix.

Determination of the Critical Conditions of Ignition and Fast Reaction for Explosive Powder

HU Dong, WANG Yong-Guo, SUN Zhu-Mei

1999, 13(3): 178-183 . doi: 10.11858/gywlxb.1999.03.004

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Abstract:
The reaction degreed of TATB, RDX, TNT explosive powders under different excitation conditions were studied by means of temperature measurement, recovery and spectrum detecting techniques. Results show that both the critical ignition temperature and pressure for TATB explosive powder are high for TNT and RDX are small. A comparison of the present results with those in literature is given.

Single Pulse Shock Tube Study on Decomposition and Incipient Detonation of the Trinitrotoluene

HE Yu-Zhong, CUI Ji-Zing

1999, 13(3): 184-186 . doi: 10.11858/gywlxb.1999.03.005

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Abstract:
Dilute quantities of o-nitrotoluene and anthranil have been pyrolyzed in comparative rate single pulse shock tube experiments. Rather a lot of CNO2 bond cleavages than NO2 isomerization are found as major channels in p-nitrotoluene decomposition. We demonstrate that the important pathway for pyrolysis involves the formation of anthranil with the following overall rate expression: k(o-nitrotolueneanthranil) =1.21013exp (-26 020/T) s-1. The anthranil that is formed is very unstable under our conditions, the rate expression for disappearance has been found to be the following: k(Anthranil)d＝3.71015exp(－25 800/T) s-1.

Two-Dimensional Numerical Simulation for the Inertial Effect of EMV Gauge Moving with Detonation Wave

ZHANG Zhen-Yu, WANG Zhi-Bing, HUANG Tie-Jun, LU Fang-Yun, HUAN Shi

1999, 13(3): 187-191 . doi: 10.11858/gywlxb.1999.03.006

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Abstract:
The inertial effect of EMV gauge, for measuring particle velocity of detonation wave, which is simulated by two dimensional nonlinear finite-element dynamic analyses, is presented in the paper.

Birch-Murnaghan Equation of State and High Pressure Compressibility of Halloysite

GONG Zi-Zheng, JING Fu-Qian, XIE Hong-Sen, TAN Hua

1999, 13(3): 192-198 . doi: 10.11858/gywlxb.1999.03.007

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Abstract:
K0S and K0S, the zero pressure adiabatic bulk modulus and its first pressure derivative of Birch-Murnaghan EOS (isentrope) for halloysite, are obtained in terms of shock Hugoniot data by using the Eulerian finite strain theory. Under the assumption =0.43(0/), for the low pressure phase K0S=32.16 GPa and K0S=7.17, but we find K0S=103.28 GPa, K0S=4.97 and K0S=95.85 GPa, K0S=5.35 for the high pressure phase, with the phase transition energy of 579.1 and 1 000 J/g, respectively, under ＝1.0(0/)1.5. Analysis for the compressibility of its low-pressure phase, high-pressure phase and mixed-phase indicate that the different compressibilities between them corresponding to their different phase compositions.

Underwater Explosion Wave by a Spherical Charge of Composition B-3

CHI Jia-Chun, MA Bing

1999, 13(3): 199-204 . doi: 10.11858/gywlxb.1999.03.008

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Abstract:
Peak pressures of underwater explosion wave by a spherical charge of composition B-3 are measured by using manganin gauge, PVDF gauge and tourmaline gauge over scaled distance of 1R/R0400, and the attenuation of the peak pressure is obtained. The explosion energy of composition B-3 is worked out from pressure profiles obtained by tourmaline gauges and the data of the first pulsation period of gas bubble. This energy is similar to the value from the explosion heat test. This result proves the possibility of assessment of explosive energy by using underwater explosion test.

Study on Simulation of Plasma in a Discharge Capillary

LIU Dong-Yao, ZHOU Yan-Huang, YU Yong-Gang

1999, 13(3): 205-210 . doi: 10.11858/gywlxb.1999.03.009

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Abstract:
An isothermal time-dependent zero dimension model of plasma in a discharge-capillary is developed in this paper. The variation of the resistance of metal wires, the ablation and ionization details of capillary materials and the non-ideal characters of the plasma are considered in this model. The discharge process of the capillary is simulated by this model, and the dynamic processes of the plasma characters are obtained. Simulation and experimental results are compared. The agreement of the theory and the experiment is discussed; it proves the engineering feasibility of this model.

The Experimental Technology for Shock-Compressed Liquid Gas

SHI Shang-Chun, DONG Shi, HUANG Yue

1999, 13(3): 211-217 . doi: 10.11858/gywlxb.1999.03.010

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Abstract:
The technology of shock-compression of liquid gas is reported in this paper. The liquid sample, which is refrigerated by liquid nitrogen, were shocked from initial states at 0.807 g/cm3 and 0.808 g/cm3 for CO and N2, respectively, to pressure range of 10～57 GPa using a two-stage light-gas gun. The shock velocity vs mass velocity for liquid nitrogen and liquid carbon monoxide were measured, and electrical conductivity for liquid nitrogen were measured too. The engineering problems about how to combine the cryogenic system with the sample target, the inner target-chamber and its outer, the cryogenic-target and measuring-detectors et al, are discussed. In addition, the problems of measuring and controlling of the temperature of cryogenic-target, and hw to determine the liquid is or not full filled in the sample cavity are also discussed.

Influence of the Inclination of the Fiber End Surface in Calibration of Coupling Energy of a Pyrometer

HU Jin-Biao

1999, 13(3): 218-225 . doi: 10.11858/gywlxb.1999.03.011

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Abstract:
The influence of inclination of the fiber end surface to coupling energy of a pyrometer and variation of the accepting angle of the fiber caused by the inclination is calculated. Results show that the inclination of the fiber end surface influences the coupling energy very much. At the same time, the inclination of the fiber end surface makes the accepting angle of the fiber a great deal. Connecting these results with the actual experiment and calibration situation, the influence of inclination of the fiber end surface to calibration is discussed and a more effective calibration technique is proposed.

A New Route for the Synthesis of MoN

ZHAO Xu-Dong, RANGE K J, WU Xiang

1999, 13(3): 226-229 . doi: 10.11858/gywlxb.1999.03.012

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Abstract:
The Molybdenum nitride was synthesized by the reduction of Molybdenum dioxide with ammonium chloride under extreme conditions of high pressure and high temperature. The product was examined with XRD measurement. The results show that the MoN has the hexagonal symmetry with lattice constants of a=0.572 nm, c=0.560 nm, and space group of P63/mmc. The Mo atoms are at the positions 2b (0, 0, 1/4) and 6h (x, 2x, 1/4), x=0.489, the N atoms are at the positions 2a (0, 0, 0) and 6g (0.5, 0, 0). This method is very easy to be attached, and get the pure phase, as well as need a short time to react.

Experimental Studies on the Nano-Crystallizations of Amorphous Fe78B13Si9 and FeMoBSi Alloy under Shock Wave

LIU Ying-Kai, ZHOU Xiao-Feng, LIU Zuo-Quan, HOU De-Dong

1999, 13(3): 230-236 . doi: 10.11858/gywlxb.1999.03.013

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Abstract:
The shock wave-crystallizations of amorphous Fe78B13Si9 and (Fe0.99Mo0.01)78B13Si9 alloys are studied. The shock wave was produced in a H2 and O2 explosive shock wave tube. The experimental results suggest that the nano-crystallization of metallic glasses Fe78B13Si9 and (Fe0.99Mo0.01)78B13Si9 could be completed under shock wave within the time of the order of s and that the first crystallized phase is solid solution of -Fe and the second phase is Fe3Si. Besides, the lattice constant of -Fe solid solution is determined to be smaller than that of pure Fe. DTA analysis indicates that the shock wave-crystallization is very complete and the first crystallized phase is rather stable.

H-Derivative of the Function Defined on Fractal Set

DONG Xiao-Dan, JI Hui, CHEN Yong-Shun, JIANG Yi-He, LI Rui, WU Yu-Xia, LI Wei

1999, 13(3): 237-240 . doi: 10.11858/gywlxb.1999.03.014

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Abstract:
In this paper, H-derivative of the function defined on fractal set is given as follows f(1)HE(S0)=limS0 |f(S0)/2S|D1D2～|fE(S)|D1D2 and the evolution equation of fractal dynamics is proved.

1999 Vol. 13, No. 3

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