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亭南煤矿综放开采矿山压力数值模拟

辽宁工程技术大学学报（自然科学版） 2009年第1期28卷 9-12页

作者：李树刚潘宏宇赵庆民 steve niu 西安科技大学能源学院陕西西安710056 陕西长武亭南煤业有限责任公司陕西长武713600 美国SHAWD大学 NC 94101

为了分析综放工作面顶板断裂、垮落形式,以及工作面支承压力分布及影响区域范围,对亭南煤矿101综放面,分别应用UDEC与FLAC3D软件进行了数值模拟对比分析。结果表明随工作面的推进,直接顶出现离层、破断,并在采空区前后煤壁上方基岩出现... 详细信息

为了分析综放工作面顶板断裂、垮落形式,以及工作面支承压力分布及影响区域范围,对亭南煤矿101综放面,分别应用UDEC与FLAC3D软件进行了数值模拟对比分析。结果表明随工作面的推进,直接顶出现离层、破断,并在采空区前后煤壁上方基岩出现拉裂缝。当工作面推进到60 m左右,老顶出现初次破断,形成初次来压,之后工作面每推进30 m,老顶出现周期来压。模拟结果再现了顶板冒落、离层、破断,综放面初次、周期来压及围岩应力集中、重新分布等现象,这些结果与现场矿山压力观测结果基本吻合,为矿压观测提供了直观、准确的数值分析方法。

关键词：支承压力 UDEC FLAC3D 数值模拟周期来压

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傅里叶域锁模光电振荡器的锁模匹配精度研究

光学学报 2022年第10期42卷 219-226页

作者：牛嘉琪郝鹏王凯姚晓天河北大学物理科学与技术学院光信息技术创新中心河北保定071002 河北省光学感知技术创新中心河北保定071002

为研究傅里叶域锁模光电振荡器(FDML OEO)的锁模匹配精度,首先通过分析FDML OEO在滤波器调谐周期与环路延迟时间整倍数存在误差时的起振过程,研究建立FDML OEO开环增益、可调滤波器半波带宽、扫频输出带宽与傅里叶域锁模匹配精度之间的... 详细信息

为研究傅里叶域锁模光电振荡器(FDML OEO)的锁模匹配精度,首先通过分析FDML OEO在滤波器调谐周期与环路延迟时间整倍数存在误差时的起振过程,研究建立FDML OEO开环增益、可调滤波器半波带宽、扫频输出带宽与傅里叶域锁模匹配精度之间的关系;随后选取FDML OEO的输出线性扫频信号延时自外差拍频信号的相位噪声作为振荡器输出信号质量的评价参数。通过实验验证FDML OEO中可调谐滤波器半波带宽、系统开环增益与傅里叶域锁模匹配精度之间的关系;实验分析了傅里叶域匹配精度对FDML OEO输出射频信号带宽的影响。实验结果与理论相一致,结果表明:可调谐滤波器的半波带宽越大,开环增益越大,傅里叶域锁模的匹配精度要求越低;傅里叶域锁模输出频率范围越大,对傅里叶域锁模的匹配精度要求越高;失谐情况越严重,FDML OEO可实现的最大扫频范围将越小。该研究结果为宽带、低相噪FDML OEO的发展提供了重要的技术理论参考。

关键词：光学器件傅里叶锁模光电振荡器可调射频滤波器相位噪声

Opportunities to search for extraterrestrial intelligence with the FAST

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Research in Astronomy and Astrophysics 2020年第5期20卷 193-204页

作者： Di Li Vishal Gajjar Pei Wang Andrew Siemion Zhi-Song Zhang Hai-Yan Zhang You-Ling Yue Yan Zhu Cheng-Jin Jin Shi-Yu Li Sabrina Berger Bryan Brzycki Jeff Cobb steve Croft Daniel Czech David DeBoer Julia DeMarines Jamie Drew J.Emilio Enriquez Nectaria Gizani Eric J.Korpela Howard Isaacson Matthew Lebofsky Brian Lacki David H.E.MacMahon Morgan Nanez Chen-Hui niu Xin Pei Danny C.Price Dan Werthimer Pete Worden Yunfan Gerry Zhang Tong-Jie Zhang FAST Collaboration CAS Key Laboratory of FAST National Astronomical ObservatoriesChinese Academy of SciencesBeijing 100101China University of Chinese Academy of Sciences Beijing 100049China Department of Astronomy University of California BerkeleyBerkeley CA 94720USA SETI Institute Mountain ViewCA 94043USA Department of Astrophysics/IMAPP Radboud UniversityNijmegenNetherlands University of Malta Institute of Space Sciences and AstronomyMalta Space Sciences Laboratory University of CaliforniaBerkeleyBerkeley CA 94720USA Breakthrough Initiatives NASA Research ParkMoffett Field CA 94043USA Hellenic Open University School of Science&TechnologyParodos AristotelousPerivola PatronGreece University of Southern Queensland QLD 4350Australia Xinjiang Astronomical Observatory Chinese Academy of SciencesUrumqi 830011China Centre for Astrophysics&Supercomputing Swinburne University of TechnologyHawthornVIC 3122Australia Department of Astronomy Beijing Normal UniversityBeijing 100875China Institute of Astronomical Science Dezhou UniversityDezhou 253023China

The discovery of ubiquitous habitable extrasolar planets,combined with revolutionary advances in instrumentation and observational capabilities,has ushered in a renaissance in the search for extraterrestrial intelligence(SETI).Large scale SETI activities are now underway at numerous international *** Five-hundred-meter Aperture Spherical radio Telescope(FAST)is the largest single-aperture radio telescope in the world,and is well positioned to conduct sensitive searches for radio emission indicative of *** is one of the five key science goals specified in the original FAST project plan.A collaboration with the Breakthrough Listen Initiative was initiated in 2016 with a joint statement signed both by *** Yan,the then director of National Astronomical Observatories,Chinese Academy of Sciences(NAOC),and *** Worden,Chairman of the Breakthrough Prize *** this paper,we highlight some of the unique features of FAST that will allow for novel SETI *** identify and describe three different signal types indicative of a technological source,namely,narrow band,wide-band artificially dispersed and modulated ***,we propose observations with FAST to achieve sensitivities never before *** nearby exoplanets,such as TESS targets,FAST will be sensitive to an EIRP of 1.9×1011 W,well within the reach of current human *** the Andromeda Galaxy,FAST will be able to detect any Kardashev type II or more advanced civilization there.

关键词： Search for Extraterrestrial Intelligence Five-hundred-meter Aperture Spherical radio Telescope

在基因1、2、3或6型的HCV感染患者中使用索磷布韦+利巴韦林±聚乙二醇干扰素:来源于中国的一项3期研究结果

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在基因1、2、3或6型的HCV感染患者中使用索磷布韦+利巴韦林±聚乙...