Influence of parameters of a fault on coal mining above a confining aquife

根据流固耦合理论,采用有限元数值模拟的方法,针对承压水体上采煤过程中断层参数(断距、倾角)对煤层、围岩的应力、变形和水压力变化的影响进行了模拟分析,探讨了存在断层时突水的机理和可能的突水点位置,并定量分析了防水煤柱的预留距离.得出以下结论:(1)当存在正断层时,多发生断层破坏型突水,而底板破坏型突水发生的几率较小;(2)突水性质和突水发生位置受断层断距和倾角的影响不大,煤层和采煤工作面附近的底板围岩都可能成为突水涌出点;(3)随着断层断距和倾角的增加,防水煤柱的合理留设距离应随之增大.以上结果可为实际矿井采煤防突水设计提供参考

Efficient computation of ultraviolet radiation from bow shock waves

Ultraviolet(UV)emissions radiated by nitric oxide(NO)and hydroxyl radical(OH)in the bow shock experiment[1]are computed using the direct simulation Monte Carlo(DSMC)method and the Navier–Stokes equations,respectively.Compared to previous studies[2,3],the trace species separation(TSS)algorithm[4]i..

中国科学院力学研究所高温气体动力学国家重点实验室;

再入过程中的电子数密度,在一定高度范围,随着再入高度的降低而增大。给定通讯频率,通讯中断的始发高度,是实际关心的问题。为了弄清通讯中断机理,美国在上世纪60年代,历时10年,开展一系列飞行试验[1,2],RAM C-II是其中的一次。根据文献[2]报道,RAM C-II试验测量得到的电子密度,随时间波动,最大值与最小值相差约3倍(图1)。这种差别被认为缘自飞行攻角的影响,因为在飞行过程中,飞行器有滚转,电子密度测量仪有时处于迎风面,有时处于背风面。虽然有许多研究者对RAM C-II的电子密度进行了计算,但几乎

断层参数对承压水体上采煤的影响分析

根据流固耦合理论,采用有限元数值模拟的方法,针对承压水体上采煤过程中断层参数（断距、倾角）对煤层、围岩的应力、变形和水压力变化的影响进行了模拟分析,探讨了存在断层时突水的机理和可能的突水点位置,并定量分析了防水煤柱的预留距离。得出以下结论：（1）当存在正断层时,多发生断层破坏型突水,而底板破坏型突水发生的几率较小;（2）突水性质和突水发生位置受断层断距和倾角的影响不大,煤层和采煤工作面附近的底板围岩都可能成为突水涌出点;（3）随着断层断距和倾角的增加,防水煤柱的合理留设距离应随之增大。以上结果可为实际矿井采煤防突水设计提供参考

JUNO Sensitivity on Proton Decay p→νˉK+p\to \bar\nu K^+ Searches

The Jiangmen Underground Neutrino Observatory (JUNO) is a large liquid scintillator detector designed to explore many topics in fundamental physics. In this paper, the potential on searching for proton decay in $p\to \bar\nu K^+$ mode with JUNO is investigated.The kaon and its decay particles feature a clear three-fold coincidence signature that results in a high efficiency for identification. Moreover, the excellent energy resolution of JUNO permits to suppress the sizable background caused by other delayed signals. Based on these advantages, the detection efficiency for the proton decay via $p\to \bar\nu K^+$ is 36.9% with a background level of 0.2 events after 10 years of data taking. The estimated sensitivity based on 200 kton-years exposure is $9.6 \times 10^{33}$ years, competitive with the current best limits on the proton lifetime in this channel

JUNO sensitivity on proton decay p → ν K + searches*

The Jiangmen Underground Neutrino Observatory (JUNO) is a large liquid scintillator detector designed to explore many topics in fundamental physics. In this study, the potential of searching for proton decay in the $p\to \bar{\nu} K^+$ mode with JUNO is investigated. The kaon and its decay particles feature a clear three-fold coincidence signature that results in a high efficiency for identification. Moreover, the excellent energy resolution of JUNO permits suppression of the sizable background caused by other delayed signals. Based on these advantages, the detection efficiency for the proton decay via $p\to \bar{\nu} K^+$ is 36.9% ± 4.9% with a background level of $0.2\pm 0.05({\rm syst})\pm$$0.2({\rm stat})$ events after 10 years of data collection. The estimated sensitivity based on 200 kton-years of exposure is $9.6 \times 10^{33}$ years, which is competitive with the current best limits on the proton lifetime in this channel and complements the use of different detection technologies