高压物理学报

In Situ Electrical Measurement in Diamond Anvil Cell Equipped with Microcircuit by Integration Technology

GAO Chun-Xiao

2013, 27(1): 1-18. doi: 10.11858/gywlxb.2013.01.001

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Abstract:
Diamond anvil cell (DAC) can produce more than 400 GPa ultra-high pressure and have been used widely in high pressure science. By means of laser heating, about 6 000 K high temperature can be realized in DAC. In the past 20 years, many technical progresses in microcircuit fabrication on DAC have been made by using film integration technology, and a series of achievement in in-situ electrical measurement with DAC have been obtained. Today, most electrical parameters measured at normal condition can be obtained in DAC. In this article, the history and progress of the integration technology related to fabricating microcircuit on DAC for electrical measurement under high pressure have been comprehensively reviewed, and the latest technological advances have also been introduced.

Axial Friction Calibration for 3 GPa Molten Salt Medium Triaxial Pressure Vessel under High Pressure and High Temperature

LIU Zhao-Xing, ZHOU Yong-Sheng, LIU Gui, HE Chang-Rong, ZHONG Ke, YAO Wen-Ming, HAN Liang, DANG Jia-Xiang

2013, 27(1): 19-28. doi: 10.11858/gywlxb.2013.01.002

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Abstract:
The axial friction calibration of 3 GPa molten salt medium triaxial pressure vessel under high pressure and high temperature is performed based on the calibration of the temperature and confining pressure of the apparatus, which mainly analyses the effects from different experimental conditions, such as the confining pressure, the temperature, and type of salt cell used around the sample. The results show that the axial friction includes static friction, squeezing friction and sliding friction between the piston and the surrounding material. Three types of friction play different roles in axial stress, in which sliding friction is the main factor that affects axial stress precision, while static fiction and squeezing friction have little effects on axial stress. The static and sliding frictional force has a positive correlation to the confining pressure. The axial piston velocity has a positive effect on static friction, too, but the effect is not significant, while it has no effect on sliding friction. Both static and sliding friction has a negative correlation to the experimental temperature, and the effect of temperature is significant. The type of salt cell has a great effect on axial friction. The axial friction drops dramatically as the experimental temperature approaches the melting point of the salt. The procedure of calibrating axial friction is made based on the results, and the axial friction calibration is applied to stress-strain curves for deformation experiments of amphibole. It is found that it is more reliable that the deformation curve with the calibration of axial friction than the curve without calibration.

Effects of Pressure on the Structure of CoFe2O4/SiO2 Nanocomposites

LI Ji, WANG Li, JIA Xiao-Peng, LI Hai-Bo

2013, 27(1): 29-33. doi: 10.11858/gywlxb.2013.01.003

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Abstract:
Combined with sol-gel technology and high-pressure and high-temperature technique, CoFe2O4/SiO2 nanocomposites are fabricated. The structure and magnetic property of the nanocomposites are monitored by X-ray diffraction (XRD), scanning electron microscope (SEM) and vibrating sample magnetometer (VSM). The results show that the lattice constant of CoFe2O4 decreases but the grain size increases with increasing treatment pressure in the experiment. Moreover, the specific saturation magnetization increases gradually with increasing treatment pressure. According to the calculation results, it can be concluded that the increasing pressure leads to the Fe3+ ions transfer from A sites to B sites and the Co2+ ions transfer from B sites to A sites.

Enlarged Scale Tests on Diamond Synthesis by Pressure Transmitting and Sealing Medium with Inside Diameter of 42 mm and Composed of Kaolinite and Dolomite

YANG Bing-Fei, LIU Jie

2013, 27(1): 34-39. doi: 10.11858/gywlxb.2013.01.004

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Abstract:
Kaolinite can take the place of pyrophyllite in the use of pressure transmitting and sealing medium due to its good sealing performance, pressure transmitting property and machining capability. The selected kaolinite sample in this paper is not pure mineral, but it is more suitable for the pressure transmitting and sealing. A new pressure transmitting and sealing medium composed of kaolinite and dolomite is obtained through batching, mixing, shaping, and roasting. With this pressure transmitting and sealing medium, a large number of diamond synthesis tests are conducted. The test results show that the per unit yield of diamond is 19 g, the proportions of crystals whose compression strength and grain size are more than 160 N and 0.30 mm are 32% and 82%, respectively, and the cemented carbide anvil consumption is less than 0.5 g per 1 g of the produced diamond. In addition, the synthesis process observed is stable. Compared with pyrophyllite, the selected kaolinite-dolomite can also achieve considerable effect.

Research on Formation Process of Wrapping Explosively Formed Compound Penetrator

WANG Shu-You, MEN Jian-Bing, JIANG Jian-Wei

2013, 27(1): 40-44. doi: 10.11858/gywlxb.2013.01.005

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Abstract:
Wrapping explosively formed compound penetrator (WEFCP) under blasting of shaped charge covered by reactive material is introduced. Shaped charge with various thickness and small length-diameter ratio is analyzed using numerical simulation software AUTODYN. The cover effects of main structural parameters are considered, and the formation process of WEFCP is recorded by impulse X-ray to get a better structure scheme. The simulation is proved to be reliable by experimental results.

Detonation Characteristics of Emulsion Explosives Sensitized by MgH2

CHENG Yang-Fan, MA Hong-Hao, SHEN Zhao-Wu

2013, 27(1): 45-50. doi: 10.11858/gywlxb.2013.01.006

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Abstract:
The theoretical calculations and underwater explosion experiments are performed to investigate the detonation characteristics of the emulsion explosive sensitized by MgH2. The results show that compared with the emulsion explosives sensitized by glass microspheres, the emulsion explosive sensitized by MgH2 has a great increase in underwater explosion shock wave overpressure, specific impulse, shock wave specific energy and specific bubble energy, and it is noticeable that the shock wave overpressure and shock wave specific energy increase by over 20.5% and 31.0% respectively. In addition, the detonation reaction mechanism of the emulsion explosive sensitized by MgH2 is also analyzed. MgH2 plays double roles in the emulsion explosive which acts as both sensitizer and energetic material. First MgH2 is hydrolyzed in the emulsion matrix, and then a lot of hydrogen bubbles appear and distribute evenly, and at last the emulsion matrix is sensitized and can be detonated by a detonator. The explosion energy is also improved, since H2 participates in the explosion reaction and alters the detonation reaction process of the emulsion explosive.

Shock Synthesis of N-Doped Titania and Its Photocatalytic Activity under Visible Irradiation

LIU Jian-Jun, ZHANG Hong-Ling, CHEN Peng-Wan, GAO Xiang, CUI Nai-Fu

2013, 27(1): 51-56. doi: 10.11858/gywlxb.2013.01.007

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Abstract:
Shock transformation and shock-induced chemical reaction in materials can lead to their obvious changes of physical and chemical properties. In this paper, the powder mixtures of nitrogen-rich of C2N4H4 and P25 TiO2 or metatitanic acid were shocked by the impact of flyer plates driven by explosive detonation, and the recovered samples were characterized by X-ray diffraction, transmission electron microscopy, X-ray photoelectron spectroscopy, Brunauer-Emmett-Teller (BET) surface area analysis and UV-Vis spectra and evaluated by the photocatalytic degradation of methylene blue and Rhodamine B. The results indicate that the doping level of nitrogen-doped TiO2 reaches 8.88% (atom fraction) using the P25 TiO2 as raw materials which exhibits obvious absorption in visible region. Its energy gap decreases to 1.75 eV together with the formation of srilankite high-pressure phase. The doping level is 3%-4% (atom fraction) corresponding to the small variation of the energy gap using the metatitanic acid as raw materials. The specific surface area of the sample increases dramatically due to the unique shock dehydration-expansion mechanism. The nitrogen-doped TiO2 have better adsorption capability and photocatalytic activity under visible irradiation for the degradation of methylene blue and Rhodamine B, among which treated at higher impact velocity shows the higher photocatalytic activity.

A High Temperature SHPB Impact Experimental Technique and Its Application

XU Jin-Yu, LIU Jian, FAN Fei-Lin, REN Wei-Bo, XI Yang-Yang, YANG Kun

2013, 27(1): 57-62. doi: 10.11858/gywlxb.2013.01.008

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Abstract:
A set of temperature-controlling system adapted to high temperature split Hopkinson pressure bar (SHPB) experiments is developed and presented. Using this high temperature SHPB system comprised of a temperature-controlling system and a general 100 mm SHPB apparatus, the dynamic mechanical properties of concrete are investigated at 20, 200, 400, 600, 800 and 1 000 ℃, respectively. The experimental results show that the temperature-controlling system composed of a box preheating furnace and a tube real-time heating device is convenient to operate and can improve efficiency greatly, and the sample assembly method is simple and feasible; the temperature variance of sample and the local temperature rising of pressure bar due to heat conduction can be ignored, and the experimental technique is reliable. Temperature effects on dynamic mechanical properties of concrete at high temperature are obvious. With temperature increasing, the average strain rate and dynamic peak strain increase gradually, and the dynamic stress-strain curves exhibit plastic properties; moreover, the dynamic compressive strength rises at first and then falls.

Experimental Study on Shape and Evolution of Water Column Caused by Near Surface Explosion in Deep Water Area

LI Mei, WEI Ji-Feng, WANG Shu-Shan, MA Feng

2013, 27(1): 63-68. doi: 10.11858/gywlxb.2013.01.009

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Abstract:
In order to investigate the shape and evolution process of water column caused by a near surface explosion in deep water situation, underwater explosion experiments with 1 kg of RDX charge at different detonation depths are carried out using a high-speed camera. The evolution characteristics and parameters of water columns including the height, width and prominent time are obtained and compared with those published by Cole, Hole and Swisdak et al. The results show that vertical ejection is the main shape of water column, and a few additional radial ejections occur when the bubble reaches the free surface at its expanding phase. The maximum height of water column fluctuates with the explosion depth, while the width of water column decreases linearly. Empirical formula of water column height by Swisdak is not suitable to near surface underwater explosion in deep water situation.

Strengthening and Toughening Effect of Ceramic Fiber on Plain Concrete

SU Hao-Yang, XU Jin-Yu, GAO Zhi-Gang, LI Zhi-Wu, YANG Kun

2013, 27(1): 69-75. doi: 10.11858/gywlxb.2013.01.010

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Abstract:
A hydraulic pressure testing machine and a 100 mm diameter split Hopkinson pressure bar (SHPB) apparatus are used to investigate the quasi-static and dynamic mechanical properties of ceramic fiber reinforced concrete (CRFRC), which are compared to those of carbon fiber reinforced concrete (CFRC) at the same volume fractions of 0.1%, 0.2% and 0.3%. The strengthening mechanism of ceramic fiber is analyzed. The experimental results show that the ceramic fiber improves the quasi-static mechanical property of plain concrete effectively. When the volume fraction is 0.3%, the compressive strength, splitting tensile strength and flexural strength enhance by 15.0%, 8.5% and 12.7% respectively. The dynamic compressive strength and specific energy absorption of CRFRC are strain rate-dependent under impact load, and the effect can be expressed by linear approximations. The strength and toughness of CRFRC come to the best at the volume fraction of 0.2%. The strength and energy absorption properties of CRFRC are superior to those of CFRC as a whole.

Numerical Simulation of Cylindrical Shell Loaded by Explosive Rods (Ⅱ): Decoupling Analysis and Experimental Validation

MAO Yong-Jian, LI Yu-Long, CHEN Ying, DENG Hong-Jian, HUANG Hai-Ying, ZHOU Qing, HUANG Han-Jun

2013, 27(1): 76-82. doi: 10.11858/gywlxb.2013.01.011

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Abstract:
According to the previous simulation results of two-dimensional fluid-structure interaction, the model of impulsive load generated by a single explosive rod and shaped by the buffer is built. Then the loads generated by multiple explosive rods are superposed and applied on the surface of the cylindrical shell, and a two-dimensional decoupled simulation is performed. The results basically agree with those of the fluid-structure interaction simulation. Based on that, a three-dimensional decoupled simulation of the 265 mm380 mm cylindrical shell loaded by 19 explosive rods is accomplished. Meanwhile, the corresponding test is performed. There shows a good agreement between the three-dimensional numerical and tested strain histories at typical locations. These results prove the effectiveness of decoupled numerical simulation and provide a foundation for improving the modeling and computational efficiency in performing a large number of numerical simulations.

Distribution Law of Pressure on Liner Surface under Multi-Point Initiation

ZHAO Chang-Xiao, LONG Yuan, JI Chong, LI Yu-Chun, XIE Quan-Min, LU Liang

2013, 27(1): 83-89. doi: 10.11858/gywlxb.2013.01.012

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Abstract:
In order to investigate the distribution law of pressure on the liner surface and the effect of initiation point parameter on the pressure distribution, the interaction of detonation waves with each other and with the liner is simulated by LS-DYNA software. The simulation results coincide well with the experimental data. The results of the study indicate that detonation waves collide with each other on the symmetry plane of the initiation points, and the pressure of collision position increases, which make the pressure distribution of liner uneven. While the distance between initiation points is bigger, the pressure of tip liner increases quickly, but the pressure of edge region of liner decreases gradually. When the distance is 50 mm, the pressure drops suddenly, namely the distance has a maximum value. The pressure of liner increases with the number of initiation point, but the increase rate reduces gradually, and the pressure distribution laws on the liner surface with different initiation numbers are similar. The conclusions can supply a theoretical basis for choosing appropriate initiation point parameters of the explosively formed projectile with star shaped tail.

A Numerical Study on Interface Evolution and Jet Development of a Shocked SF6 Gas Bubble

ZOU Li-Yong, LIU Cang-Li, PANG Yong, LUO Xi-Sheng, BAI Jin-Song, YANG Ji-Ming

2013, 27(1): 90-98. doi: 10.11858/gywlxb.2013.01.013

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Abstract:
The Richtmyer-Meshkov instability occurring on a heavy gas (SF6) bubble surrounded by N2 is numerically investigated in the present work. The interface evolution, shock focusing and jet development are emphasized. Numerical schlieren images and distributions of pressure, density and vorticity are exhibited for an incident shock wave of Mach number 1.23. The jet velocity, circulation and baroclinic torque versus time as well as peak values of pressure and density in the flow field are quantitatively analyzed. The results indicate that SF6 gas bubble accelerated by a planar shock wave has a strong cumulative energy effect so that it produces nearly ideal shock focusing and point source explosion phenomenon near the downstream pole within the bubble interface, which directly results in a secondary wave pattern and a slender jet moving in the streamwise direction. Compared with the secondary wave pattern, the incident shock wave brings on more intense baroclinic torque and vorticity.

Influence of Surface State on the Crater Formation of Metallic Material Surface Irradiated by High Current Pulsed Electron Beam

WANG Xiao-Tong, PENG Dong-Jin, ZOU Yang, WAN Ming-Zhen, CAI Jie, GUAN Qing-Feng

2013, 27(1): 99-104. doi: 10.11858/gywlxb.2013.01.014

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Abstract:
In order to investigate the influence of crystallographic properties of materials on the formation mechanism of surface craters, high current pulsed electron beam (HCPEB) was used to irradiate a 304 austenitic stainless steel with and without shot peening treatment. The morphologies of surface crater induced by HCPEB were characterized in detail. The experimental results indicate that a large number of volcano-like craters are inevitably formed on the surface sample after HCPEB irradiation. The number density and dimension of craters decrease with the increase in electron beam energy. It is found that inclusions on the surface layer easily become the new nucleation sites of craters; however, they are gradually removed during the period of eruption in the formation of the crater, and showing a surface purification effect. Additionally, it is established that the number density of craters on shot peening samples is significantly increased than untreated ones. The number densities of craters on the samples with and without shot peening treatment follow the similar law. The present results indicate that the crystallographic properties of materials have a great importance to the formation of surface craters, and the structure defects, such as grain boundaries and dislocations are the preferred sites of the nucleation of craters.

Optimal Structural Design of Stuffed Shields with Kevlar Fiber Clothes against Hypervelocity Impact

ZHANG Bao-Xi, HA Yue, DENG Yun-Fei, PANG Bao-Jun

2013, 27(1): 105-112. doi: 10.11858/gywlxb.2013.01.015

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Abstract:
A series of impact experiments are conducted to investigate the ballistic performances of stuffed Whipple shields with Kevlar fiber clothes using a two-stage light gas gun facilities. Based on the impact limit curve of Nextel/Kevlar stuffed Whipple shields, the protective performances of Kevlar stuffed Whipple shields, the damage morphology and mechanism of stuffed material and bulkhead are obtained and compared. The main results show as following: the stuffed Whipple shields with Kevlar fiber clothes have excellent protection performance at the low impact velocity; the double-layer packing structure can improve the protective performance. Kevlar fibers sufficiently absorb energy by plastic deformation and fracture when the impact velocity is low. In addition, high temperature melting and carbonization phenomenon appear in the hypervelocity region, which help break up and melt the projectiles that minimize the damage to cabin wall. This exploratory method provides us a useful way to make the ballistic performances of stuffed Whipple shields more perfect in space debris protection field.

Interference on Logic Chips due to Plasma Created by Hypervelocity Impact on 2024-T4 Aluminum Target

TANG En-Ling, ZHANG Qing-Ming, WANG Meng, XIANG Sheng-Hai, ZHANG Wei, YANG Ming-Hai, LI Le-Xin, YU Hui, LUO Rong-Mei, ZHAO Xin-Ying

2013, 27(1): 113-118. doi: 10.11858/gywlxb.2013.01.016

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Abstract:
To acquire the interference status of typical logic chips in spacecraft caused by plasma generated from a hypervelocity impact, the triple Langmuir probe system established by selfishness is used for diagnostics of plasma characteristic parameters created by 2024-T4 aluminum projectile hypervelocity impact on 2024-T4 aluminum target, with the impact velocity and incidence angle of 6.10 km/s and 30, respectively. The plasma electron density is measured at a given position with a given azimuth, and the interference estimation is performed for logic chip by data acquisition system. The experimental results show that the logic chips in spacecraft will be seriously influenced by plasma generated at hypervelocity impact.

Calculation of Detonation Parameters of Special Explosives

WANG Xiao-Hong, LI Xiao-Jie, LI Rui-Yong, YAN Hong-Hao

2013, 27(1): 119-124. doi: 10.11858/gywlxb.2013.01.017

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Abstract:
The calculation code based on BKW (Becker-Kistiakowsky-Wilson) equation of state was programmed, which was not only able to calculate the detonation parameters of traditional explosives containing C, H, O and N elements but also calculate those of some special explosives containing plenty of other metal elements. The detonation parameters of the emulsion explosives containing Fe and Mn elements and the water-gel explosives containing Al element were calculated using this new code and were compared with the experimental values and the data from published papers and original BKW program. The results indicated that the calculated parameters are well satisfied with those obtained from experimental data with the relative error less than 1%. In the calculation process, only the chemical formula, density and formation heat of explosives at normal temperature and pressure are needed.

Measurement of Dynamic Friction Coefficient of Several Typical Pyrotechnics

JIANG Xi-Bo, GUO Song, FENG Song, PENG Jin-Hua

2013, 27(1): 125-131. doi: 10.11858/gywlxb.2013.01.018

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Abstract:
Friction is important in the production and application of pyrotechnics, and the dynamic friction coefficient is a key parameter for quantitative analyzing the friction work. A new method for determining the dynamic friction coefficient is presented, which combines the physical model of MGY-1 friction device with theoretical analysis and numerical calculations. The dynamic friction coefficients of three pyrotechnic simple substances including potassium nitrate, magnesium and aluminum alloy and sulfur, and two pyrotechnic compounds are measured using this method. The results show that the dynamic friction coefficients of the pyrotechnics are range values, and the dynamic friction coefficient of potassium nitrate decreases with the addition of magnesium and aluminum alloy and sulfur. Moreover the reasons for producing above two phenomena are analyzed theoretically.

Detonation Propagation in 180 Ribs of an Insensitive Explosive

JIANG Yang, LI Lei, WANG Tao, ZHONG Min, LI Ping, BAI Jin-Song

2013, 27(1): 132-136. doi: 10.11858/gywlxb.2013.01.019

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Abstract:
Non-ideal detonation wave propagation in 180 ribs of an insensitive high explosive is studied using the DSD (Detonation Shock Dynamics) method which is combined with the LS (Level Set) method in body-fitted coordinate. The rule of detonation wave propagation in 180 explosive ribs is obtained through comparing and analyzing the computed and experimental results. The explosive ribs can detonate in steady state regime, and in this case the detonation front is steady as viewed in a system of polar coordinates rotating with a fixed angular velocity. The shape and angular velocity of this steady front is independent of the outer radius of the rib. The formation of steady-state regime depends on the rib dimensions and the material of the shells covering the rib edges. Some experimental formulae describing the detonation front propagation in explosive ribs are also studied. It is shown that the change of detonation wave velocity can be accurately described by these experimental formulae, which have reference value for experimental measurement and estimation.

Quality Changes of Strawberry Nectar Processed by Ultra High Pressure during Storage

XU Wen-Wen, CAO Xia-Min, LIU Feng-Xia, LIAO Xiao-Jun

2013, 27(1): 137-146. doi: 10.11858/gywlxb.2013.01.020

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Abstract:
The bacterial phase and qualities of strawberry nectar treated by ultra high pressure (600 MPa, 4 min) at storage of 4 ℃ for seven months are studied. The experimental results show that there are no aerobic bacteria, yeasts or molds detected in the strawberry nectar during storage, from the microbial safety point of view, which indicates that ultra high pressure processing at 600 MPa for 4 min can be used as an alternative preservation method for extending its shelf life. No significant changes are observed for the total soluble solid content, pH value and titratable acidity during storage. However, the color gradually darkens, the contents of total phenols, vitamin C and anthocyanins significantly decrease (P0.05), and the DPPH (1,1-diphenyl-2-picrylhydrazyl) radical scavenging capacity and ferric reducing ability of plasma decrease (P0.05) with the prolongation of the storage period. In addition, the esters in the strawberry nectar significantly reduce, and the relative contents of the representative aromatic compounds including linalool and nerol in the strawberry nectar increase dramatically during the storage process (P0.05).

Review on Sterilization Effects of High Pressure Thermal Sterilization on Bacterial Spores

ZHANG Zhong, HU Xiao-Song, LIAO Xiao-Jun, ZHANG Yan

2013, 27(1): 147-152. doi: 10.11858/gywlxb.2013.01.021

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Abstract:
This review introduces in detail the advantages and applications of high pressure thermal sterilization. The latest research results on the sterilization effects and kinetics of various bacterial spores by this technology are described deeply and comprehensively, and the sterilization mechanism is also preliminarily summarized. Furthermore, this review analyzes the remaining problems and points out the future research direction in field of high pressure thermal sterilization.

2013 Vol. 27, No. 1

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