高密度纤维模压板门(也称 MM 门),是优质木纤维经特殊工艺和配方加工,在高压下模压成型的。具有金属门和塑料门所不能替代的宜人性,可在高度工业化的人造环境中重现自然美。"MM 门"是八十年代美国研制出的。利用干法中纤板的...高密度纤维模压板门(也称 MM 门),是优质木纤维经特殊工艺和配方加工,在高压下模压成型的。具有金属门和塑料门所不能替代的宜人性,可在高度工业化的人造环境中重现自然美。"MM 门"是八十年代美国研制出的。利用干法中纤板的生产设备。展开更多
The design and implementation of a novel ADC architecture called ring-ADC for digital voltage regulator module controllers are presented. Based on the principle of voltage-controlled oscillators＇ transform from volta...The design and implementation of a novel ADC architecture called ring-ADC for digital voltage regulator module controllers are presented. Based on the principle of voltage-controlled oscillators＇ transform from voltage to frequency,the A/D conversion of ring-ADC achieves good linearity and precise calibration against process variations compared with the delay-line ADC. A differential pulse counting discriminator also helps decrease the power consumption of the ring-ADC. It is fabricated with a Chartered 0.35μm CMOS process, and the measurement results of the integral and differential nonlinearity performance are 0.92LSB and 1.2LSB respectively. The maximum gain error measured in ten sample chips is ± 3.85%. With sampling rate of 500kHz and when the voltage regulator module （VRM） works in steady state, the ring-ADC＇s average power consumption is 2.56mW. The ring-ADC is verified to meet the requirements for digital VRM controller application.展开更多
In the analysis of a structure subjected to an explosion event, the determination of the blast load constitutes a crucial step. The effect of the blast load on the structure depends not only on the peak shock overpres...In the analysis of a structure subjected to an explosion event, the determination of the blast load constitutes a crucial step. The effect of the blast load on the structure depends not only on the peak shock overpressure, but also the impulse (hence the duration). For structures with a regular geometry, the blast load may be fairly well estimated using appropriate empirical formulae; however, for more complex situations, a direct simulation using appropriate computational techniques is necessary. This paper presents a numerical simulation study on the prediction of the blast load in free air using a hydrocode, with focus on the sensitivity of the simulated blast load to the mesh grid size. The simulation results are compared with empirical predictions. It is found that the simulated blast load is sensitive to the mesh size, especially in the close-in range, and with a practically affordable mesh grid density, the blast load tends to be systematically underestimated. The study is extended to internal blast cases. An example concrete slab under internal explosion is analyzed using a coupled analysis scheme. The internal blast load from the simulation is examined and the response of the RC slab is commented.展开更多
Since the CPU of embed system has some limitation in operating speed, a new filter was put forward which implemented mountain template convolution by performing rectangle template convolution two times. It can obtain ...Since the CPU of embed system has some limitation in operating speed, a new filter was put forward which implemented mountain template convolution by performing rectangle template convolution two times. It can obtain time and frequency localization with computational complexity greatly reduced. This algorithm was applied to lightning waveforms (include chopped waveforms) parameter calculation. It simplifies the computation and the results pretreated by this algorithm are in accord with IEC1083-2 completely. It was applied in embed system successfully. Its capability in frequency restraining was researched. The validity of the algorithm was proved in theory when processing lightning waves. The standard sources and the processing results are consistent completely.展开更多
The forms of roof break,roof fall,and effects of the region scope in a fully mechanizedtop-coal caving (FMTC) face of the 101 fully-mechanized top coal caving face ofthe Tingnan Coalmine were analyzed by UDEC and FLAC...The forms of roof break,roof fall,and effects of the region scope in a fully mechanizedtop-coal caving (FMTC) face of the 101 fully-mechanized top coal caving face ofthe Tingnan Coalmine were analyzed by UDEC and FLAC^(3D) software.The analysis resultconfirms the phenomenon of roof falling,roof-off-strata,roof breaking,first weighting,periodicweighting and stress concentration,redistributions of surrounding rock and so on.Itprovides the gist to analyze the law of roof movement,characteristic of confining pressure,and to determine the formative structure forms of the immediate roof and main roof duringthe caving process.These results and the underground pressure observation results are inagreement.展开更多
文摘The design and implementation of a novel ADC architecture called ring-ADC for digital voltage regulator module controllers are presented. Based on the principle of voltage-controlled oscillators＇ transform from voltage to frequency,the A/D conversion of ring-ADC achieves good linearity and precise calibration against process variations compared with the delay-line ADC. A differential pulse counting discriminator also helps decrease the power consumption of the ring-ADC. It is fabricated with a Chartered 0.35μm CMOS process, and the measurement results of the integral and differential nonlinearity performance are 0.92LSB and 1.2LSB respectively. The maximum gain error measured in ten sample chips is ± 3.85%. With sampling rate of 500kHz and when the voltage regulator module （VRM） works in steady state, the ring-ADC＇s average power consumption is 2.56mW. The ring-ADC is verified to meet the requirements for digital VRM controller application.
文摘In the analysis of a structure subjected to an explosion event, the determination of the blast load constitutes a crucial step. The effect of the blast load on the structure depends not only on the peak shock overpressure, but also the impulse (hence the duration). For structures with a regular geometry, the blast load may be fairly well estimated using appropriate empirical formulae; however, for more complex situations, a direct simulation using appropriate computational techniques is necessary. This paper presents a numerical simulation study on the prediction of the blast load in free air using a hydrocode, with focus on the sensitivity of the simulated blast load to the mesh grid size. The simulation results are compared with empirical predictions. It is found that the simulated blast load is sensitive to the mesh size, especially in the close-in range, and with a practically affordable mesh grid density, the blast load tends to be systematically underestimated. The study is extended to internal blast cases. An example concrete slab under internal explosion is analyzed using a coupled analysis scheme. The internal blast load from the simulation is examined and the response of the RC slab is commented.
文摘Since the CPU of embed system has some limitation in operating speed, a new filter was put forward which implemented mountain template convolution by performing rectangle template convolution two times. It can obtain time and frequency localization with computational complexity greatly reduced. This algorithm was applied to lightning waveforms (include chopped waveforms) parameter calculation. It simplifies the computation and the results pretreated by this algorithm are in accord with IEC1083-2 completely. It was applied in embed system successfully. Its capability in frequency restraining was researched. The validity of the algorithm was proved in theory when processing lightning waves. The standard sources and the processing results are consistent completely.
基金Supported by the National Natural Science Foundation of China (505740720,50874089)the National Natural Science Foundation of Shannxi Province(2006E203)
文摘The forms of roof break,roof fall,and effects of the region scope in a fully mechanizedtop-coal caving (FMTC) face of the 101 fully-mechanized top coal caving face ofthe Tingnan Coalmine were analyzed by UDEC and FLAC^(3D) software.The analysis resultconfirms the phenomenon of roof falling,roof-off-strata,roof breaking,first weighting,periodicweighting and stress concentration,redistributions of surrounding rock and so on.Itprovides the gist to analyze the law of roof movement,characteristic of confining pressure,and to determine the formative structure forms of the immediate roof and main roof duringthe caving process.These results and the underground pressure observation results are inagreement.
