高压物理学报

Effects of Pressures on 111 Iron-Based Superconductors

JIN Chang-Qing, LIU Qing-Qing, DENG Zheng, ZHANG Si-Jia, XING Ling-Yi, ZHU Jin-Long, KONG Pan-Pan, WANG Xian-Cheng

2013, 27(4): 473-480. doi: 10.11858/gywlxb.2013.04.001

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Abstract:
Here we briefly review the effects of pressure on what we have discovered about 111 iron based superconductor. The record high superconductor transition temperature (Tc) up to 31 K in 111 system is reached with applied pressure. The isostructural evolution with applied pressure reveals an intimate link between the As-Fe-As bond angle and bond length as well as the pressure-tuned superconductivity of 111 system using a synchrotron X-ray powder diffraction technique.

Compressional and Shear Wave Velocities of Rock Glasses up to 2.0 GPa and 1 000 ℃

JIANG Xi, ZHOU Wen-Ge, XIE Hong-Sen, LIU Yong-Gang, FAN Da-Wei

2013, 27(4): 481-489. doi: 10.11858/gywlxb.2013.04.002

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Abstract:
Measurements of compressional and shear wave velocities (vp and vs) under pressure from 0.4 to 2.0 GPa were performed on seven types of synthetic glasses, including basalt, andesite, dacite, amphibolite, pyroxenite, rhyolite and gneiss. At confining pressure of 2.0 GPa, the wave velocities were also measured as functions of temperature up to 1 000 ℃ for compressional wave velocity (vp) and up to 730 ℃ for shear wave velocity (vs). At room temperature, the wave velocities of the glasses decrease anomalously with pressure, as a result of the open structure of SiO2 in silica-rich glasses. With varying SiO2 mass fraction in the glasses from 87% to 52%, dvp/dp increases from -0.159 to 0.050 m/(sPa), and dvs/dp increases from -0.114 to -0.001 m/(sPa). At 2.0 GPa, vp and vs of the glasses decrease slowly first up to 600-700 ℃, indicating the glass transition temperatures (Tg), and then decrease rapidly. Based on the elastic properties of basalt glass and mantle rocks, it is concluded that the basalt glass with volume fraction of about 20% in matrix can cause the low velocity zone in upper mantle.

Liquid-Liquid Phase Transition of Water at High Pressure and Ambient Temperature

WANG Hui-Yuan, ZHENG Hai-Fei

2013, 27(4): 490-494. doi: 10.11858/gywlxb.2013.04.003

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Abstract:
In-situ Raman measurement of water has been conducted at the temperature of 300 K and the pressure of 0.1-1 400 MPa using a SiC anvil cell. The experimental results show that the frequency of liquid water 1 decreases with increase of pressure (p), and two discontinuities are observed at about 200 and 620 MPa. Therefore three states of water are recognized. From state Ⅰ to state Ⅱ then to state III, the value of |d1/dp| reduces, indicating that the compressibility is related to the pressure, and it is becoming more difficult to compress as the pressure is increasing. The connection mode of a water molecule with its neighboring water molecules changes as the pressure increases. The discontinuous property of water suggests a possible liquid to liquid phase transition and structural change at 200 and 620 MPa.

Electrical Transport Properties of PbSe Prepared by High Pressure and High Temperature

SU Tai-Chao, XU An-Tao, LI Hong-Tao, LI Shang-Sheng, FAN Hao-Tian, MA Hong-An, JIA Xiao-Peng

2013, 27(4): 495-499. doi: 10.11858/gywlxb.2013.04.004

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Abstract:
Consistent with the state of art thermoelectric material PbTe, PbSe belongs to group Ⅳ-Ⅵ semiconductor. And PbSe has the same crystal structure as PbTe. But there are few reports about PbSe as thermoelectric material. A large number of studies show that the thermoelectric performance of PbTe is improved effectively under high pressure. In this paper, PbSe was synthesized by high pressure and high temperature method. The phase compositions and microstructures of PbSe were characterized by X-ray diffraction (XRD) and scanning electron microscope (SEM). The electrical properties measurement results show that PbSe sample synthesized under high pressure has low electrical resistivity and high power factor, and therefore it is a promising thermoelectric material applicable to thermoelectric power generation.

Effects of High Pressure Treatment on Microstructure and Compressive Strength of Aluminum Bronze

WANG Hai-Yan, LI Ya-Li, CHEN Yan, LIU Jian-Hua, ZHANG Rui-Jun

2013, 27(4): 500-504. doi: 10.11858/gywlxb.2013.04.005

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Abstract:
The effects of high pressure treatment on the compressive strength of aluminum bronze were investigated, based on the measurement of its compressive strength, the analysis of its phase composition, and the observation of its microstructure and fracture morphology by means of electronic universal testing machine, X-ray diffraction, optical microscope, transmission electron microscope (TEM), and scanning electron microscope (SEM). The results show that high pressure treatment is favorable to form fine-grained microstructures and can reduce the compressive strength of aluminum bronze, while the compressive strength of the aluminum bronze treated at 2 GPa and kept at 600 ℃ for 2 min is increased about by 34%, compared with the as-cast alloy.

Measurement System of Transient Raman Spectroscopy and Its Application to Benzene under Shock Compression

CHEN Yuan-Fu, LIU Fu-Sheng, ZHANG Ning-Chao, ZHAO Bei-Jing, WANG Jun-Guo, ZHANG Ming-Jian, XUE Xue-Dong

2013, 27(4): 505-510. doi: 10.11858/gywlxb.2013.04.006

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Abstract:
A new measurement system for transient Raman spectroscopy under gas-gun loading and the Raman spectra of shocked benzene have been reported in this paper. The experimental results show that the Raman shifts of C-H stretching mode (3 061 cm-1) are linearly dependent of shock pressure between 0.8 GPa and 3 GPa. The extrapolation of the present results agrees well with the published experimental data. It shows that the new measurement system has good stability and repeatability, and it is an effective method to study the structural changes at the molecular level of transparent and semi-transparent materials under dynamic loading conditions.

A Transverse VISAR for Measuring Free Surface Transverse Velocity of Detonation-Driven Wedge Target

CHEN Guang-Hua, LIU Jun, MENG Jian-Hua, PENG Qi-Xian, YUAN Shu-Yun, WANG De-Tian, DENG Xiang-Yang

2013, 27(4): 511-516. doi: 10.11858/gywlxb.2013.04.007

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Abstract:
A transverse velocity interferometer system for any reflector (VISAR) has been developed by combination of a multipoint VISAR and a tri-probe device. One probe emits and receives laser, and the other two probes receive laser from different directions. The transverse and longitudinal velocities can be deduced from Doppler shift of laser received by the tri-probe. The transverse VISAR were applied to detonation driving wedge target experiments. Planar shock wave in a 10 wedge steel target was generated by plane-wave lens and T/ explosive. The free surface transverse velocities induced by oblique collision of shock wave were measured. The maximum measured longitudinal velocity is about 1 680 m/s, and the maximum measured transverse velocity is about 140 m/s. The uncertainty of the transverse velocity measurement was analyzed, and the uncertainty is estimated to be about 33 m/s in the experiments.

A Hydraulic Opposite Anvil System for High-Pressure in-Situ Neutron Diffraction

HUI Bo, HE Duan-Wei, LU Yu-Ping, CHEN Xi-Ping, ZHANG Ying, SUN Guang-Ai, CHEN Bo

2013, 27(4): 517-522. doi: 10.11858/gywlxb.2013.04.008

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Abstract:
A hydraulic opposite anvil system (HAL-11) consisting of an inner anvil cell, a hydraulic loading system, and an alignment system, is developed for high pressure in-situ neutron diffraction. The inner anvil cell can be compatible with various anvils with different culet sizes and materials, such as WC, sapphire, SiC, and sintered polycrystalline diamond. A maximum load up to 500 kN can be provided by the hydraulic loading system through a hydraulic jack with hand pump, and the pressure decline caused by the rheology of gasket and specimen can be compensated during the high pressure in-situ neutron diffraction experiments. The opposite anvil system attached on a four dimensional pensile-type translational stage is aligned by means of two lasers, and the entire system can be easily assembled and distributed. The pressure calibration results show that the sample pressure is above 12 GPa with WC anvils at a loading force of about 150 kN.

Frequency Aliasing Used in Interior Ballistic Velocity Measurements for Gas Guns

TAO Tian-Jiong, WANG Xiang, CHEN Hong, WANG Wei, FU Qiu-Wei, WANG Xiao-Song

2013, 27(4): 523-527. doi: 10.11858/gywlxb.2013.04.009

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Abstract:
The occurrence of frequency aliasing and its representation in time and frequency domain are analyzed with sampling theory. Relationship between the sampled signal and the original signal is calculated and shows that the frequency of the original signal can be recovered by using the rule of frequency aliasing. Ideal sampled signals with frequency aliasing are simulated, and the frequency recovering method is confirmed by numerical simulations. The interior ballistic velocity in a two-stage light gas gun is measured by a laser displacement interferometer and the optical beam break method. The frequency of the laser interference signal recovered by aliasing rules is the same as the frequency obtained from the optical beam break method, which solves the contradiction between the recording length and the sampling frequency in high velocity measurements of long time duration, such as interior ballistic velocity measurement.

Experimental Measurement and Numerical Simulation of Incident Shock Wave Pressure on the Fluid-Solid Interface

NI Xiao-Jun, MA Hong-Hao, SHEN Zhao-Wu, JIANG Yao-Gang, LI Lei

2013, 27(4): 528-534. doi: 10.11858/gywlxb.2013.04.010

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Abstract:
In order to research the mid-far field pressures of the incident shock wave on the fluid-solid interface, an experiment was designed to measure the shock wave pressure, by means of two PVDF piezoelectric film sensors laid on the bottom of double shell. The experimental process was simulated by the finite element method software ANSYS/LS-DYNA. The simulation results are in good agreement with the experimental data. PVDF sensor can be used to measure the incident shock wave pressure on the fluid-solid interface. The mid-far field pressures of the incident shock wave on the fluid-solid interface can be gained, which is important to evaluate the antiknock performance of ships.

Experimental Investigation of Protection Performance about Aluminum Mesh Bumper by High-Velocity Normal Impact

GUAN Gong-Shun, NIU Rui-Tao, BI Qiang, PANG Bao-Jun

2013, 27(4): 535-541. doi: 10.11858/gywlxb.2013.04.011

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Abstract:
The high-velocity normal impacts of space debris on bumper of spacecrafts were studied through a two-stage light gas gun launching 2017-T4 aluminum spheres to impact on 5052 aluminum mesh shield structure. The resist capability of aluminum mesh shield against high-velocity impact was discussed. For the same areal density, the size effect and arrangement effect on the protection performance of the filled layer were analyzed. Impact velocities of Al-spheres were varied between 2.90 and 4.95 km/s in this study. The diameters of projectiles were 3.97 and 6.35 mm respectively. The impact angle was 0. The results indicated that the primary capability of the 2A12 aluminum plate comminuting projectile is better than that of 5052 aluminum mesh when the areal density is constant, but as the filled medium, the 5052 aluminum mesh layer provides better protection for the rear wall than 2A12 aluminum plate. In a certain wire diameter range, the 5052 aluminum mesh with smaller wire diameter has better protection performance. Al mesh-Al plate filled layer can break up the projectile to a more uniform size than Al plate-Al mesh filled layer.

A Study on Characteristics of Plasma Generated by Hypervelocity Impact

LI Jian-Qiao, SONG Wei-Dong, NING Jian-Guo

2013, 27(4): 542-548. doi: 10.11858/gywlxb.2013.04.012

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Abstract:
The characteristics of the plasma generated by hypervelocity impact have been studied by theoretical analysis and numerical simulation. Based on the theory of thermodynamics and statistical physics, a model of thermal ionization is proposed to describe the relationship between the degree of ionization and temperature. Plasma conductivity related to temperature is obtained by considering the velocity distribution law at heat balance. Three-dimensional model of an aluminum plate impacted by a spherical projectile with 6.0 km/s at an angle of 60 is established, and the corresponding simulation is performed. Then the parameters of the physical model are obtained, and the characteristics of plasma generated by hypervelocity impact are analyzed. There is a good agreement between the model predictions and the experiment results, which indicates that the model is effective and reasonable for analyzing the characteristics of plasma.

Influence of the Number of Layers on the Ballistic Resistance of Layered Thin Q235 Steel Plates

DENG Yun-Fei, ZHANG Wei, CAO Zong-Sheng, SONG Jian, WANG Qing-Lin

2013, 27(4): 549-555. doi: 10.11858/gywlxb.2013.04.013

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Abstract:
Layered plates are normally impacted by ogival, blunt and hemispherical projectiles using a gas gun to investigate the influence of the number of layers on the ballistic resistance and target failure model. The residual velocity versus the initial velocity curves for the projectiles are constructed, and ballistic limit velocities are obtained. Based on the experimental data, the monolithic targets show greater ballistic limit velocity than multi-layered targets. For blunt and ogival projectile, the ballistic limit velocity decreases with increasing of the number of layers. However, for hemispherical projectile, the ballistic limit velocity firstly decreases and then increases with the increase of the number of layers. The influence of layering decreases as the impact velocity of projectile increases.

Powder Liner Density Effect on the Performance of Shaped Charge Jet

GAO Yong-Hong, GU Xiao-Hui, WANG Feng-Ying

2013, 27(4): 556-560. doi: 10.11858/gywlxb.2013.04.014

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Abstract:
In order to study the relation of powder liner material density and performance of the shaped charge jet, the curves of shaped jet velocity, jet particle momentum and jet particle kinetic energy with respect to the liner density were calculated under the same charge conditions, according to the Birkhoffs steady theory and Gurneys formula of crushed speed. In the same charge structure, the jet velocity and penetration power of two kinds of powder liner were tested, whose mass ratios of W to Cu were 0.5∶0.5 and 0.4∶0.6 respectively. It is found that the experimental results are well in agreement with the calculation results. Therefore, it is considered that the calculated curves have certain reference values, and the penetration power can be increased effectively by improving the density of powder liner.

Ballistic Trajectory of High-Velocity Projectile Obliquely Penetrating Concrete Target

WANG Ke-Hui, NING Jian-Guo, LI Zhi-Kang, GENG Bao-Gang, ZHOU Gang

2013, 27(4): 561-566. doi: 10.11858/gywlxb.2013.04.015

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Abstract:
The experiments of small scale projectile obliquely penetrating a semi-infinite concrete target with a velocity from 980 to 1 870 m/s are performed by a two-stage light gas gun. The ballistic trajectory and characteristic parameters are tested and painted. The results show that the trajectory deflection of the penetrator obliquely penetrating a semi-infinite concrete target with high velocity is more obvious than that with intermediate and low velocities, and presents a shape of J. The penetration process can be divided into four phases according to the penetration mechanism. In addition, it is found that the terminal gesture of the projectile changes greatly, and the deflection angle at endpoint can reach up to 130.

Local Damage Effects of X70 Steel Pipe Subjected to Contact Explosion Loading

JI Chong, LONG Yuan, TANG Xian-Shu, GAO Zhen-Ru, LI Yu-Chun

2013, 27(4): 567-574. doi: 10.11858/gywlxb.2013.04.016

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Abstract:
Field explosion experiments were carried out to investigate the contact explosion damage effects of large diameter X70 steel oil-gas pipes. The contact explosion damage characteristics of pipes with different pipe wall thickness under various charge were analyzed. The experimental results show that the local damage of the pipe wall facing explosion is predominant and there is a petal-shaped crevasse. In addition, the fragments with abundant kinetic energy are formed. The dent or perforation phenomenon will occur after the opposite pipe wall is impacted by the fragment. By means of an explicit nonlinear dynamic finite element computer code LS-DYNA, the nonlinear dynamic response process of the steel pipe under contact explosion loading was numerically simulated with Lagrangian-Eulerian coupling method. The damage process of the pipe wall facing explosion and the after effects of opposite pipe wall due to the impact of fragment were described. The numerical simulation results are in good agreement with experimental data. The results can provide important reference for the blast resistant properties analysis and safety assessment of oil-gas pipes.

Numerical Simulation on the Damage and Hot-Spot Formation in Warhead Charge under Shock

CHENG Li-Rong, SHI Hui-Ji, CHEN Rong

2013, 27(4): 575-581. doi: 10.11858/gywlxb.2013.04.017

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Abstract:
In order to solve the difficult problem about the security of warhead in the penetration process, the relationship between damage and hot-spot formation in the charge has been researched. Based on crack friction under mechanical impact, a thermo-viscoelasticity constitutive model for explosive materials coupling the crack damage and hot spot formation is presented to analyze the formation of hot spot in warhead charge during penetration. The influence factors of hot-spot formation under different penetration conditions are discussed and compared. The numerical simulation method provided can be used to design and evaluate the security of loaded projectiles under impact.

An Experimental Study on the Capacity for Work of Insensitive High Explosive

XU Hui, SUN Zhan-Feng

2013, 27(4): 582-586. doi: 10.11858/gywlxb.2013.04.018

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Abstract:
The capacity for work of insensitive high explosive JB-9014 was studied and compared with high explosive JOB-9003, by improved standard cylinder test, in which combined streak photography and laser interference technique. The results indicate that the capacity for work of JB-9014 is less than that of JOB-9003 evidently. After the expanding velocity is relatively stable, the capacity for work of JB-9014 is about 68.56% of JOB-9003 at the same expanding time and about 69.39% at the same radial displacement. The ratio of capacity for work of JB-9014 and JOB-9003 increases with expanding time and radial displacement gradually, which is consistent with the distinct performance of insensitive high explosive.

Effect of Experimental Conditions on the Experimental Results of Underwater Explosion

ZHANG Xing-Ming, XU Sen, GAO Xin, LIN Hui, ZHANG Jian-Xin

2013, 27(4): 587-591. doi: 10.11858/gywlxb.2013.04.019

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Abstract:
In order to obtain information about the influence of experimental conditions on the results of underwater explosion, the relationships between measure position, explosion depth and explosion parameters, which contain shock overpressure, shock wave energy per unit mass, bubble pulsation period and bubble energy per mass, were studied by experiments. The results show that the peak pressure of shock wave and shock wave energy per unit mass decrease with the increment of distance between measuring position and explosive sample, the bubble pulsation period increases and bubble energy per mass decreases with the increasing of the explosion depth. The distance between the measuring position and explosion position are at least greater than twice of the bubble radius, and the explosion depth should be 1/3 to 3/4 of the tank depth.

Study of Pressure on the Inner Wall of Powder Cold Shock-Wave Extinguishing Bomb

JIANG Yao-Gang, MA Hong-Hao, SHEN Zhao-Wu, FAN Zhi-Qiang, WANG Quan

2013, 27(4): 592-598. doi: 10.11858/gywlxb.2013.04.020

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Abstract:
In order to study the shell fragmentation and the early motion of extinguishing medium after explosion in the cold shock-wave extinguishing system, the pressure on the inner wall of the cold shock-wave extinguishing bomb must be firstly understood. The change of pressure has been studied by dimensional analysis, mechanical structure, and explosion experiments. It is found that the pressure is related to the charge weight and bomb diameter, and the pressure waveform measured at the inner wall is rectangular. When the bomb diameter is 104 mm, the duration of high pressure is above 100 s; when the bomb diameter is 220 mm, the duration of high pressure is above 200 s. In addition, the specific central explosive charge of powder is more than that of water under the same dimension of the cold shock-wave extinguishing bomb to reach better effect of the shell crushing. Owing to the higher energy dissipation during compression, the finer powder and pre-compression powder are suggested as extinguishing medium in powder cold shock-wave extinguishing system.

Propagation of Non-Ideal Detonation Wave Confined by Inert Medium

JIANG Yang, LI Yuan, TANG Mi, ZHONG Min, TAN Duo-Wang

2013, 27(4): 599-603. doi: 10.11858/gywlxb.2013.04.021

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Abstract:
In order to have an insight into the propagation of non-ideal detonation wave confined by inert medium, the shock polar method relating the pressure/streamline-deflection matching condition at the explosive/inert medium interface was adopted. The detonation front shape and the pressure distribution were calculated by this method combined with detonation shock dynamics (DSD) method and the program describing detonation acceleration. Comparison between experimental data and numerical simulation results shows that although a detailed description for interaction between the detonation wave and the inert medium needs full hydrodynamic simulation in the complete flow field, a relatively simple shock polar analysis can also provide a good prediction of the interaction effect, which is consistent with the argument from Aslam et al. of United States of America.

Advances in High Pressure Processing Reducing the Allergenicity of Food Proteins

LONG Fang-Yu, SHI Xue-Ping, WANG Rong-Rong, JIANG Bin, DONG Peng, HU Xiao-Song

2013, 27(4): 604-608. doi: 10.11858/gywlxb.2013.04.022

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Abstract:
As a new non-thermal technology, high pressure processing destroys vegetative microorganisms and inactivates enzymes, whereas fresh flavour, colour, mineral balance and vitamins mostly persist. In addition, high pressure processing has been investigated to decrease the allergenicity of food protein. Combination with other treatments (such as thermal) and agents (such as enzyme), allergenicity can be almost eliminated. This paper reviews literature on the recent advances in eliminating or decreasing the allergenicity of food protein by high pressure treatment. The mechanisms of high pressure treatment induced alteration of allergenicity are also discussed.

Effects of High Hydrostatic Pressure on the Solubility and Molecular Structure of Rice Protein

WANG Zhang-Cun, TIAN Wei-Huan, CUI Sheng-Wen, ZHAO Xue-Wei, ZHENG Jian-Qiang, LI Chang-Wen, YUAN Dao-Qiang

2013, 27(4): 609-615. doi: 10.11858/gywlxb.2013.04.023

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The effects of high hydrostatic pressure (HHP) treatment at 100-500 MPa for 10-30 min on the solubility and molecular structure characteristics of thermal denatured rice protein dissolved in solvent A (water solution, pH 8.0) and solvent B (containing 6 mol/L urea and 1% mercaptoethanol, pH 8.0) were researched. The results showed that the solubility of rice protein in solvent B was notably improved after HHP treatment, especially at 100 MPa for 20 min, which was from 6.89% at 0.1 MPa up to 18.13%, while in solvent A, it was from 4.37% to 9.60% at the same pressure condition. SDS-PAGE analysis showed that the subunit composition of soluble protein treated under HHP in solvent A had few differences from that of untreated. The similar phenomena could be seen in insoluble protein. However in solvent B, the relative contents of the subunits in soluble changed obviously. The observation of SEM (Scanning Electron Microscope) showed that the surface structure and aggregation state of rice protein could be changed by HHP treatment.

Effect of High Pressure Processing on the Quality of Chilled Stored Grass Carp (Ctenopharyngodon idella) Fillet

YAKHIN Lisa Amanda, ZHANG Li-Li, WANG Yuan-Liang, LI Zong-Jun

2013, 27(4): 616-624. doi: 10.11858/gywlxb.2013.04.024

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Abstract:
This study is aimed to observe the effect of different pressure (300, 400, 500 MPa) and different pressure holding time (5, 10, 15 min) on vacuum packed grass carp fillet. The fillets were stored at chilling temperature (4 ℃) for 15 d, and the observations were carried out every 3 d. The electron micrographs showed that there were modifications on longitudinal sections (sarcomere disorganization) of muscle fiber treated by high pressure for 5 min. The K values of fish fillets treated by 400 and 500 MPa were below 70%, and they were still considered fresh at least until 6 and 12 d, respectively. Therefore, the application of high pressure processing was able to improve the shelf life of grass carp fillets. However, the application of high pressure treatment reduced the water holding capacity and increased the hardness of fish meat. In addition, the values of L*, a* and b* were all increased with the increase of storage time, and both L* and b* were increased with pressure, while a* was reduced with pressure.

Experimental Study on Rate-Dependent Constitutive Relations with Damage for Plastic-Bonded Explosives

LI Dan, ZHAO Feng, FU Hua, LI Ke-Wu

2013, 27(4): 625-632. doi: 10.11858/gywlxb.2013.04.025

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Abstract:
Cyclic loading and unloading experiments and the uniaxial compressive experiment of plastic-bonded explosives (PBX) under different strain rate were performed by a universal material testing machine. The stress-strain curves of plastic-bonded explosives were obtained in different operating conditions. Based on the idea of combining phenomenological analysis and micro-statistical analysis, a damage evolution equation with damage internal variable and rate-dependent constitutive relations with damage for plastic-bonded explosives were given. The model was checked with the experimental data, and the relevant parameters of rate-dependent constitutive relations with damage were obtained. Experimental results indicate that the constitutive equation can describe mechanical properties of the PBX explosives at the linear elastic stage, strengthen stage, and strain softening stage. The constitutive relation is simple and requires less parameters to be determined. The damage variable defined by micro-crack density can be easily determined by mechanical testing.

2013 Vol. 27, No. 4

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