Blast vibration analysis is one of the important foundations for studying the control technology of blast vibration damage. According to blast vibration live data that have been collected and the characteristics of sh...Blast vibration analysis is one of the important foundations for studying the control technology of blast vibration damage. According to blast vibration live data that have been collected and the characteristics of short-time non-stationary random signals, the wavelet packet energy spectrum analysis for blast vibration signal has made by wavelet packet analysis technology and the signals were measured under different explosion parameters （the maximal section dose, the distance of blast source to measuring point and the section number of millisecond detonator）. The results show that more than 95% frequency band energy of the signals sl-s8 concentrates at 0-200 Hz and the main vibration frequency bands of the signals sl-s8 are 70.313-125, 46.875-93.75, 15.625-93.75, 0-62.5, 42.969-125, 15.625-82.031, 7.813-62.5 and 0-62.5 Hz. Energy distributions for different frequency bands of blast vibration signal are obtained and the characteristics of energy distributions for blast vibration signal measured under different explosion parameters are analyzed. From blast vibration signal energy, the decreasing law of blast seismic waves measured under different explosion parameters was studied and the wavelet packet analysis is an effective means for studying seismic effect induced by blast.展开更多
Two-dimension consolidation under the cylindrical converging shock wave has been studied. The major parameters influenced on the explosive consolidation quality are the specific energy,detonation pressure and specific...Two-dimension consolidation under the cylindrical converging shock wave has been studied. The major parameters influenced on the explosive consolidation quality are the specific energy,detonation pressure and specific impulse.It seems to be favourable to improving con- solidation quality by a lower but slightly higher than critical detonation pressure and a high specific impulse.展开更多
Two-dimension consolidation under the cylindrical converging shock wave has been studied. The major parameters influenced on the explosive consolidation quality are the specific energy,detonation pressure and specific...Two-dimension consolidation under the cylindrical converging shock wave has been studied. The major parameters influenced on the explosive consolidation quality are the specific energy,detonation pressure and specific impulse.It seems to be favourable to improving con- solidation quality by a lower but slightly higher than critical detonation pressure and a high specific impulse.展开更多
Underwater target localization and parameters(azimuth and range) estimation by the method of utilizing explosions as underwater sound sources are described in this paper.The narrow beam reverberation model of the targ...Underwater target localization and parameters(azimuth and range) estimation by the method of utilizing explosions as underwater sound sources are described in this paper.The narrow beam reverberation model of the target echo signal is researched to estimate the target azimuth in reverberation background.Estimation errors of target azimuth and range are studied and proved to approximately meet Gauss distribution.Then the variance formula of target range error is deduced.Simulation experiments are applied to research the target range error and its standard deviation,and a series of measures to improve the estimation accuracy of target range are proposed.It is confirmed by the data processing results of simulations and lake experiments that the proposed method can accurately locate underwater target at a long distance on the condition of a certain underwater explosion range error.展开更多
A series of 1,3-bis（2-alkyltetrazol-5-yl）triazenes have been synthesized in high yields by treatment of sodium nitrite and hydrochloric acid with substituted-5-aminotetrazoles. All compounds were fully characterized...A series of 1,3-bis（2-alkyltetrazol-5-yl）triazenes have been synthesized in high yields by treatment of sodium nitrite and hydrochloric acid with substituted-5-aminotetrazoles. All compounds were fully characterized using IR spectroscopy,~1H NMR and^（13） C NMR spectroscopy and high resolution mass spectrometer（HRMS）. Most of these triazenes exhibit good detonation performance comparable with TNT and low melting points ranging from 81°C to 106°C, which are suitable for melt-cast explosives.Among these compounds, 1,3-bis（2-azidoethyltetrazol-5-yl）triazene（2g） displays a low melting point（106°C）, moderate onset decomposition temperature（183°C） and good detonation performance（D：7087 m/s; P： 17.6 GPa）.展开更多
基金Foundation item: Project(51064009) supported by the National Natural Science Foundation of ChinaProject(201104356) supported by the China Postdoctoral Science FoundationProject(20114BAB206030) supported by the Natural Science Foundation of Jiangxi Province,China
文摘Blast vibration analysis is one of the important foundations for studying the control technology of blast vibration damage. According to blast vibration live data that have been collected and the characteristics of short-time non-stationary random signals, the wavelet packet energy spectrum analysis for blast vibration signal has made by wavelet packet analysis technology and the signals were measured under different explosion parameters （the maximal section dose, the distance of blast source to measuring point and the section number of millisecond detonator）. The results show that more than 95% frequency band energy of the signals sl-s8 concentrates at 0-200 Hz and the main vibration frequency bands of the signals sl-s8 are 70.313-125, 46.875-93.75, 15.625-93.75, 0-62.5, 42.969-125, 15.625-82.031, 7.813-62.5 and 0-62.5 Hz. Energy distributions for different frequency bands of blast vibration signal are obtained and the characteristics of energy distributions for blast vibration signal measured under different explosion parameters are analyzed. From blast vibration signal energy, the decreasing law of blast seismic waves measured under different explosion parameters was studied and the wavelet packet analysis is an effective means for studying seismic effect induced by blast.
文摘Two-dimension consolidation under the cylindrical converging shock wave has been studied. The major parameters influenced on the explosive consolidation quality are the specific energy,detonation pressure and specific impulse.It seems to be favourable to improving con- solidation quality by a lower but slightly higher than critical detonation pressure and a high specific impulse.
文摘Two-dimension consolidation under the cylindrical converging shock wave has been studied. The major parameters influenced on the explosive consolidation quality are the specific energy,detonation pressure and specific impulse.It seems to be favourable to improving con- solidation quality by a lower but slightly higher than critical detonation pressure and a high specific impulse.
基金supported by the National Natural Science Foundation of China(61431020,61571434)
文摘Underwater target localization and parameters(azimuth and range) estimation by the method of utilizing explosions as underwater sound sources are described in this paper.The narrow beam reverberation model of the target echo signal is researched to estimate the target azimuth in reverberation background.Estimation errors of target azimuth and range are studied and proved to approximately meet Gauss distribution.Then the variance formula of target range error is deduced.Simulation experiments are applied to research the target range error and its standard deviation,and a series of measures to improve the estimation accuracy of target range are proposed.It is confirmed by the data processing results of simulations and lake experiments that the proposed method can accurately locate underwater target at a long distance on the condition of a certain underwater explosion range error.
基金Financial support of this work from the National Natural Science Foundation of China(No.21372027)
文摘A series of 1,3-bis（2-alkyltetrazol-5-yl）triazenes have been synthesized in high yields by treatment of sodium nitrite and hydrochloric acid with substituted-5-aminotetrazoles. All compounds were fully characterized using IR spectroscopy,~1H NMR and^（13） C NMR spectroscopy and high resolution mass spectrometer（HRMS）. Most of these triazenes exhibit good detonation performance comparable with TNT and low melting points ranging from 81°C to 106°C, which are suitable for melt-cast explosives.Among these compounds, 1,3-bis（2-azidoethyltetrazol-5-yl）triazene（2g） displays a low melting point（106°C）, moderate onset decomposition temperature（183°C） and good detonation performance（D：7087 m/s; P： 17.6 GPa）.
