高压物理学报

The Cu-12(n-1)n Superconducting Homologous Series

JIN Chang-Qing

2003, 17(4): 241-246 . doi: 10.11858/gywlxb.2003.04.001

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Abstract:
The novel superconducting homologous series CuBa2Can-1CunO2n+2+ (i. e., Cu-12(n-1)n) have been introduced. The compounds can be synthesized only under high pressure high temperature so far. The physical properties of Cu-12(n-1)n are briefly compared with other high Tc superconductors, while the advantages of the Cu-12(n-1)n superconductors in terms of simple composition, higher Tc and better high temperature high magnetic field properties are stressed.

Discussions on the VLW Equation of State

LONG Xin-Ping, HE Bi, JIANG Xiao-Hua, WU Xiong

2003, 17(4): 247-254 . doi: 10.11858/gywlxb.2003.04.002

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Abstract:
The determination of the LJ potential of detonation products used in VLW EOS is introduced. The phase state of detonation product carbon under CJ condition has been discussed by comparing the calculated data with the experimental results. The main difference between VLW EOS and BKW EOS has been pointed out and the origin of this difference has been analyzed. The performance parameters calculated by VLW EOS of a wide range of energetic materials, including high explosives, fuel-air explosives and civil explosives, is listed, and the calculations are in accord with the experimental data very well.

Numerical Simulation of One-Dimensional Instability of Detonation Wave

HONG Tao, QIN Cheng-Sen

2003, 17(4): 255-260 . doi: 10.11858/gywlxb.2003.04.003

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Abstract:
The nonlinear instability of an one-dimensional detonation wave was numerically simulated in the mixture of C2H6 and air with equivalence of 1. The influence of mesh size on the numerical results of pulsating of shock history was analyzed. Mesh size in calculation was fixed in according to the length of induction zone Lin, which was determined from ZND model to be 4.6 mm for the detonation wave in the mixture of C2H6 and air. As the decrease of mesh size, the solutions of pressure history do not tend to be identical. Detonation shock history was very irregular as the mesh size was not fine enough. As the mesh size was 0.01Lin and 0.005Lin, pulsating was regular with the mode of period-doubling mode. As the mesh size was 0.0025Lin, pulsating consisted of a series of regular oscillations and three irregular oscillations in the range of calculation, but finally the average wavelength of oscillations tended to 91~93 mm which approaches to the length of cell size of 88 mm from the experiments.

Study of the Dynamic Response of Strain-Hardening Target in High-Velocity Impact

LIANG Long-He, CAO Ju-Zhen, LI En-Zheng

2003, 17(4): 261-267 . doi: 10.11858/gywlxb.2003.04.004

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Abstract:
A dynamic cylindrical cavity expansion penetration model for compressible, elastic-plastic, rate-independent materials with power-law strain-hardening was presented. A fortran code using this model was written. We used the code to calculate the stress distribution in the target. We also used the code to predict residal velocities and ballistic limits for rigid, conical-nose projectile perforating strain-hardening target plates, and to predict the penetration depth for the same projectile penetrating into strain-hardening targets with semi-infinite thickness. We compared the model predictions of residal velocities and ballistic limits with the data from experiments with 0.026 kg tungsten projectiles impacting normally 5083-H131 aluminum armor plates. We also compared the predicted penetration depths with the experimental data or the 2-D numerically simulated results by LTZ-2D code for the 0.024 kg and the 2.96 kg maraging steel projectiles impacting normally semi-infinite 6061-T651 aluminum armor targets. Good agreements were obtained in both comparisons.

Improved LS Method for Capturing Compressible Fluid with Multi-Interface Interactions

BAI Jin-Song, CHEN Sen-Hua

2003, 17(4): 268-274 . doi: 10.11858/gywlxb.2003.04.005

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Abstract:
Based on the general LS method, an improved LS method for capturing compressible fluid with multi-interface interactions is given. This method can decrease the void region near the multi-interactions point, but not change the others. Both the LS equations capturing the material interface quality and the Eulerian conservative equations are solved by using a high resolution unspliting finite volume scheme, and fifth order WENO scheme for re-initialization level set equations. Some examination and application examples in capturing conjunct multi-fluid interfaces cases are simulated.

A Study on Square Plate Dynamic Response under Underwater Explosion

WU Cheng, JIN Yan, LI Hua-Xin

2003, 17(4): 275-282 . doi: 10.11858/gywlxb.2003.04.006

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Abstract:
To obtain more precise prediction of dynamic deformation, theoretical analysis and experimental investigations were carried out on the plasticity dynamic response of clamped square plates subject to underwater explosion loading in a water tank. Based on the principle of the energy equilibrium, the more reasonable deductive expressions were obtained for the final deflections of the shock wave upon the built-in plates subjected to the impulse loading, and the maximum large plasticity deformation solution were also obtained by the analytical plasticity method of equal-moment calculation. The different plastic deformations of the plates were measured for different charge weights and propagating distances. Both of the deformation displacements of test and theoretical calculation are quite agreement to within an about 10% discrepancy.

Effect of High Hydrostatic Pressure on Seeds Germination and Seedling Isoenzyme in Rice (Oryza sativa L.)

BAI Cheng-Ke, LI Gui-Shuang, DUAN Jun, PENG Chang-Lian, DUAN Zhong-Gang, WENG KeNan, XU Shi-Ping

2003, 17(4): 283-289 . doi: 10.11858/gywlxb.2003.04.007

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Abstract:
Three indica rice cultivars seeds, Yuexiangzhan were treated by different high hydrostatic pressure or were kept for different time. As comparison to control, both germination rate and seedling rate decreased considerably with pressure or treated time increasing. Plant growth was inhibited in treated materials during the early growth stage of seedling, but the plant height of treated cultivars could exceed that of control after sowing 30 d. The expression of some isoenzymes, esterase (EST), peroxidase (POX), superoxide dismutase (SOD) and malic enzyme (ME), was studied by polyacrylamide gel electrophoresis (PAGE), the results indicated that the expression of EST was restrained, whereas the other isoenzymes was affected lettle on expression of POX, SOD and ME. Three types of rice (Oryza sativa L.) cultivars seeds, indica cultivars (Nanjing 11 and Yuexiangzhan), japonica cultivars (Qiuguang and Taizhong 65) and intermediate type between indica cultivars and japonoca cultivars (Bulu Gendjah and Bulu Rusa), were treated by 75 MPa pressure for 10 h. The germination rate and seedling rate of three types rice all decreased. But the decrease was most significant in two indica cultivars (Nanjing 11 and Yuexiangzhan), whereas was least in two japonica cultivars (Qiuguang and Taizhong 65). The results implied that different types of rice cultivars exhibited different responses to high hydrostatic pressure. Japinica cultivars were higher resistance to high pressure than other types of cultivars. The above results showed that high hydrostatic pressure could affect the seeds germination, seedling growth and expression of EST.

VISAR Measurement on Interface Velocity between Shocked Specimen and Window

MA Yun, HU Shao-Lou, WANG Xiao-Song, CHEN Hong, LI Jia-Bo

2003, 17(4): 290-294 . doi: 10.11858/gywlxb.2003.04.008

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Abstract:
Methods and experiments of applying VISAR to measure particle velocity history at the interface between shocked Cu specimen and LiF window and LiF specimen and LiF window are described, respectively. The peak stress levels were 6.5 GPa and 3.61 GPa. Wedged LiF window was applied to smooth out the effect of the reflected light and parasitical interference from the window rear surface, and as a result the signal-to-noise ratio and the reliability of window VISAR were improved significantly.

Design of Blast Chamber for Break out Affair and Its Life-Span Evaluation

DUAN Zhuo-Ping, LI Yu-Bin

2003, 17(4): 295-300 . doi: 10.11858/gywlxb.2003.04.009

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Abstract:
An evaluation method was proposed for the design and the life-span of use of blast chamber for break out affair, and the JBG series blast chambers had been designed and built up for resisting 1.0~6.0 kg TNT blast. In order to test the ability of the resistance to blasting, explosion experiment had been done, and the remainded distortions of the shell were measured. According to the method the remainded distortions of the JBG series blast chamber loaded first time by explosion with the allowed maximum explosive mass was calculated and the life-span of use for the shell affected by repeat explosion load was evaluated. The experimental and calculated results of remainded distortion were on the whole the same.

Electrical Properties and Structural Stability of Sr2FeMoxNb1-xO6 (x=0, 0.3) under High Pressure

ZHAO Xu, YU Ri-Cheng, LI Feng-Ying, LIU Zhen-Xing, BAO Zhong-Xing, TANG Gui-De, LIU Jing, JIN Chang-Qing

2003, 17(4): 301-304 . doi: 10.11858/gywlxb.2003.04.010

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Abstract:
The resistance-pressure and capacitance-pressure relationships for double perovskite compound Sr2FeMoxNb1-xO6 (x=0, 0.3) have been studied in the pressure range of 0~20 GPa using a diamond anvil cell at room temperature. The experimental results indicate that Sr2FeNbO6 undergoes a structural transition at about 7.5 GPa while Sr2FeMo0.3Nb0.7O6 at about 2.8 GPa. According to the analysis of energy dispersive X-ray diffraction with synchrotron radiation, these are considered as electronic structure transitions caused by high pressure.

Dynamic Fracture and Mechanical Property of D6A, 921 and 45 Steels under Low Shock Pressure

ZHANG Lin, ZHANG Zu-Gen, QIN Xiao-Yun, PENG Jian-Xiang, CAI Ling-Cang, LI Yong-Chi

2003, 17(4): 305-310 . doi: 10.11858/gywlxb.2003.04.011

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Abstract:
The behaviors of dynamic damage and fracture of D6A, 921, 45 steels were studied via symmetric impact experiments. Using the double wave structure of the free-surface velocity profile and the material longitudinal elastic wave speed at room temperature, we obtained the D-up Hugoniot relations for the three steels. The Hugoniot elastic limits and spall strengths of the three steels were also obtained. A new simple phenomenal equation for describing the evolution of damage was proposed, with which the experimental spall processes were simulated.

Synthesis and Study Status of Carbon Nitride Thin Film

SONG Yin, HOU Ming-Dong, WANG Zhi-Guang, ZHAO Zhi-Ming, DUAN Jing-Lai

2003, 17(4): 311-318 . doi: 10.11858/gywlxb.2003.04.012

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Abstract:
Carbon nitride comprises super physical and chemical properties and abroad applications. Its structure and character were reviewed, and the synthetic methods, including CVD, ion beam sputtering, laser ablation, ion plating and ion irradiation et al., were completely introduced. The perspectives of the investigations of the super-hard carbon nitride were discussed by looking at the new progresses achieved in the corresponding application studies. The experimental results show that crystallites of a little cubic C－N compound dispersed in an amorphous matrix. FTIR spectroscopy showed that the films contain mainly C=C and sp2/sp3 C－C bonds. X-ray diffraction and SEM studies indicate that the deposited films may consist of the nano-sized -C3N4. Crystallites embedded in matrix of graphite form of C3N4 structure, and the crystalline phases are high enough to be detected by XRD.

Study on Microstructures and Damage Evolution of a Substitute of Polymer Bonded Explosive

ZHANG Peng, BAI Shu-Lin, ZHOU Wen-Ling

2003, 17(4): 319-325 . doi: 10.11858/gywlxb.2003.04.013

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Abstract:
A substitute of polymer bonded explosive called D-90033 was studied by using a SEM equipped with a loading system. Results indicate that the substitute is composed of two main phases, one is of grain structure, and the other lamellar structure. Under uniaxial compression, the damage and failure is caused and principally controlled by the longitudinal crack initiation and propagation along the boundary of two phases.

One-Dimensional Magneto-Hydrodynamic Simulation of Plasma Opening Switch

WANG Gang-Hua, CHEN Lin, HU Xi-Jing

2003, 17(4): 326-329 . doi: 10.11858/gywlxb.2003.04.014

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Abstract:
Preliminary results of an one-dimensional numerical code designed to investigate the magnetic field thrust effects in plasma opening switch are presented. The code is based on the magneto-hydrodynamic equations, and the current into the switch is given as a known condition. The plasma development on the axial direction is calculated. Also plasma density at different moment during the opening process is described. It is pointed out that the Hall effect plays a predominant role in the abnormal penetration of magnetic field.

An Empirical Material Constant on the Hugoniot of Solids: From Comparative Study of Porous Materials

DAI Fu, GONG Zi-Zheng, HUANG Hai-Jun, CHEN Jun-Xiang, JING Fu-Qian

2003, 17(4): 330-335 . doi: 10.11858/gywlxb.2003.04.015

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Abstract:
From the systemically comparative study of previous experimental solid Hugoniot data of different porous samples, a new material parameter , which keeps in constant along Hugoniot for all kinds of solid materials, was revealed. For different materials, the value of is different. There exist an universal power relationship between material constant and initial density 0 for metal. By using this constant , Hugoniot data between different porous samples can be converted very simply, and Grneisen parameter can also be obtained very easily. The limitation of this empirical material parameter being as a constant was discussed with variations of pressure and porosity.

2003 Vol. 17, No. 4

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