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汶川Mw7.9地震周边地区布格重力异常与岩石圈垂向构造应力场 被引量:6
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作者 付广裕 金红林 +1 位作者 王灼华 佘雅文 《地震》 CSCD 北大核心 2018年第2期28-36,共9页
前人研究给出,龙门山断裂带中南段地壳均衡异常显著,具有发生7级以上大地震的深部动力背景。2016年6月,我们围绕该均衡异常显著区域开展重力/GNSS加密观测,提高了该地区布格重力异常和地壳均衡异常场的空间分辨率。依据上述观测结果与... 前人研究给出,龙门山断裂带中南段地壳均衡异常显著,具有发生7级以上大地震的深部动力背景。2016年6月,我们围绕该均衡异常显著区域开展重力/GNSS加密观测,提高了该地区布格重力异常和地壳均衡异常场的空间分辨率。依据上述观测结果与前期同类观测数据,反演了汶川MW7.9地震周边地区地壳密度构造。结果显示,龙门山断裂带是地壳密度变化的高梯度带,其东侧地壳较薄,但其西部明显变厚,上、中、下地壳变化趋势均呈现上述特征;研究区东侧的莫霍面深度为35~40km,西侧为60~65km。此外,利用重力/GNSS联合观测数据计算了汶川MW7.9地震震中区周边地区岩石圈承载的垂向构造应力场,结果表明,汶川MW7.9地震震中区北部、宁强、峨眉山周边地区蓄积了-30 MPa至-40 MPa的负向构造应力,龙门山断裂带中南段蓄积了约40 MPa的正向构造应力,区域最大垂向构造应力分布在龙门山断裂带中南段,临近芦山MW6.6地震。统计结果表明,地震多发生在垂向构造应力高梯度带附近,或垂向构造应力的高值区域。 展开更多
关键词 汶川MW7.9地震 地壳均衡 布格重力异常 密度构造 岩石圈垂向构造应力
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东准噶尔卡拉麦里金矿带构造控矿特征及有利度分析 被引量:3
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作者 韩琼 赵同阳 +1 位作者 郑加行 孙耀锋 《地质力学学报》 CSCD 2019年第A01期21-26,共6页
东准噶尔卡拉麦里金矿带是新疆重要的成矿带之一,已经发现的金矿床(点)有100多处。区内断裂构造极为发育,主要的断裂构造有卡拉麦里深大断裂、清水—苏吉泉断裂和库普大断裂,由大断裂派生的次级断裂广泛发育,与金的成矿关系极为密切。... 东准噶尔卡拉麦里金矿带是新疆重要的成矿带之一,已经发现的金矿床(点)有100多处。区内断裂构造极为发育,主要的断裂构造有卡拉麦里深大断裂、清水—苏吉泉断裂和库普大断裂,由大断裂派生的次级断裂广泛发育,与金的成矿关系极为密切。在已有研究的基础上,借助遥感解译技术,在数理统计的基础上,总结了卡拉麦里金矿带构造控矿特征,并初步进行了有利度分析。结果表明:北西—北西西向的断裂为该成矿带内极为有利的控矿构造,其控制了成矿带的展布,与其共生的次级断裂和派生断裂为容矿构造,控制着矿床(点)的位置。北东—北东东和北东对金矿的控矿作用不明显。金矿床(点)多分布在5~15个/100 km^2的密度区内。线性构造交汇点密度高峰值为25个/100 km^2,随着密度值的增高,金矿床(点)逐趋减少。 展开更多
关键词 控矿特征 共轭断裂 线性构造密度 卡拉麦里金矿带 有利度分析
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河南省小秦岭金矿田剪切带特征及其控矿规律研究 被引量:1
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作者 刘玉刚 丁培超 +1 位作者 孙保花 刘宗彦 《黄金》 CAS 2023年第8期76-83,共8页
小秦岭金矿田位于华北陆块南缘金、钼、铅、锌多金属成矿带上,其内矿床为受剪切带控制的叠加改造型热液矿床。为研究剪切带对矿体的控制规律,从小秦岭金矿田内典型矿床的赋矿构造出发,对构造性质及形成演化过程进行了系统调查研究,发现... 小秦岭金矿田位于华北陆块南缘金、钼、铅、锌多金属成矿带上,其内矿床为受剪切带控制的叠加改造型热液矿床。为研究剪切带对矿体的控制规律,从小秦岭金矿田内典型矿床的赋矿构造出发,对构造性质及形成演化过程进行了系统调查研究,发现其先后经历了韧性剪切、脆-韧性剪切、韧-脆性剪切及脆性剪切4个构造变形阶段,金矿化强度与剪切带规模及构造密度呈正相关,且含矿剪切带的产状变化对矿段及矿体的分布起决定性作用。 展开更多
关键词 小秦岭 金矿田 构造特征 控矿规律 剪切带 金矿化 构造密度
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松辽盆地“T_2”断裂密集带成因机制及控藏机理——以三肇凹陷为例 被引量:11
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作者 谢昭涵 付晓飞 《地质科学》 CAS CSCD 北大核心 2013年第3期891-907,共17页
松辽盆地T_2反射界面高密度断层与扶杨油层油气"倒灌"运聚成藏关系密切,其成因机制备受地质学家关注,存在构造成因和水力断层等多种假说。本文系统研究了"T_2"断层几何学特征,认为该断层以南北展布方向为主、断距... 松辽盆地T_2反射界面高密度断层与扶杨油层油气"倒灌"运聚成藏关系密切,其成因机制备受地质学家关注,存在构造成因和水力断层等多种假说。本文系统研究了"T_2"断层几何学特征,认为该断层以南北展布方向为主、断距和延伸长度幂律分布、密集成带、与断陷期断层呈"似花状"组合模式、部分断层多期活动,该断层有别于超压周期性释放产生的非构造成因的多边断层,为典型的构造成因断层。T_2高密度断层和密集带的成因可以归结为3个因素:1)坳陷期松辽盆地强烈拉张发生在青山口组沉积时期,泥岩低剪切强度导致构造破碎,是高密度断层形成的前提;2)基底—断陷期断裂、火山口和基岩隆起作为早期薄弱带,控制着坳陷期断裂的形成且密集成带,是高密度断层形成的根本原因。3)塑性泥岩在坳陷期发生水平拆离作用,导致断陷期断裂与坳陷期断裂上、下不衔接,T_2和T_1断层上、下贯通较少,这是造成仅T_2反射层发育高密度断层的有力保障。构造反转期三肇凹陷整体活动较弱,断裂密集带边界断层选择性活动,向上延伸到T_(06)反射层以上,反转期活动的断层正赶上青山口组烃源岩大量生排烃时期,这些断层为扶杨和葡萄花油层有利的通道断层,控制着扶杨和葡萄花油层油气的运聚成藏与分布。 展开更多
关键词 松辽盆地 “T2”高密度断层构造成因 斜向拉张低剪切强度水平拆离
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雅鲁藏布江桑日-墨脱段岩石圈均衡研究以及虚拟水库诱发地震危险性分析 被引量:3
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作者 郭凌冬 付广裕 +2 位作者 佘雅文 王振宇 杨君妍 《地球物理学报》 SCIE EI CAS CSCD 北大核心 2021年第9期3220-3231,共12页
岩石圈均衡状态对于水库建设选址以及诱发地震风险研究具有重要参考价值.本文使用雅鲁藏布江桑日至墨脱段河谷的高精度重力/GNSS联测数据,得到沿河谷的自由空气以及布格重力异常.结果表明,该河谷布格重力异常在-500~-300 mGal之间变化.... 岩石圈均衡状态对于水库建设选址以及诱发地震风险研究具有重要参考价值.本文使用雅鲁藏布江桑日至墨脱段河谷的高精度重力/GNSS联测数据,得到沿河谷的自由空气以及布格重力异常.结果表明,该河谷布格重力异常在-500~-300 mGal之间变化.基于布格重力异常数据反演地壳密度结构,发现雅鲁藏布大峡谷上游自西到东莫霍面深度变化趋势为“深-浅-深”,大峡谷下游莫霍面自东北到西南逐渐变浅.在均一与分层地壳模型假设下,分别依据Airy均衡理论计算该河谷的均衡面深度,通过均衡面与莫霍面之间的差异计算均衡附加力的大小与方向.结果表明,基于均一地壳模型的计算结果存在较大的误差.通过计算得出,米林附近河谷的岩石圈均衡附加力为负值,在该地建设大型水库可能会带来较大的诱发地震风险;朗县附近岩石圈均衡附加力为正值,在该地建设水库诱发地震的风险较低. 展开更多
关键词 水库诱发地震 布格重力异常 均衡附加力 地壳密度构造
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平微区高速公路合理路堤高度 被引量:10
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作者 温学钧 王海燕 《长安大学学报(自然科学版)》 EI CAS CSCD 北大核心 2002年第1期14-16,共3页
经过高速公路路堤高度的研究 ,提出区域。
关键词 高速公路 路堤高度 平原微丘 人口密度 构造物设置密度
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Hazard assessment of landslide disaster using information value method and analytical hierarchy process in highly tectonic Chamba region in bosom of Himalaya 被引量:14
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作者 Kanwarpreet SINGH Virender KUMAR 《Journal of Mountain Science》 SCIE CSCD 2018年第4期808-824,共17页
The present study is focused on a comparative evaluation of landslide disaster using analytical hierarchy process and information value method for hazard assessment in highly tectonic Chamba region in bosom of Himalay... The present study is focused on a comparative evaluation of landslide disaster using analytical hierarchy process and information value method for hazard assessment in highly tectonic Chamba region in bosom of Himalaya. During study, the information about the causative factors was generated and the landslide hazard zonation maps were delineated using Information Value Method(IV) and Analytical Hierarchy Process(AHP) using Arc GIS(ESRI). For this purpose, the study area was selected in a part of Ravi river catchment along one of the landslide prone Chamba to Bharmour road corridor of National Highway(NH^(-1)54 A) in Himachal Pradesh, India. A numeral landslide triggering geoenvironmental factors i.e. slope, aspect, relative relief, soil, curvature, land use and land cover(LULC), lithology, drainage density, and lineament density were selected for landslide hazard mapping based on landslide inventory. Landslide hazard zonation map was categorized namely "very high hazard, high hazard, medium hazard, low hazard, and very low hazard". The results from these two methods were validated using Area Under Curve(AUC) plots. It is found that hazard zonation map prepared using information value method and analytical hierarchy process methods possess the prediction rate of 78.87% and 75.42%, respectively. Hence, landslide hazardzonation map obtained using information value method is proposed to be more useful for the study area. These final hazard zonation maps can be used by various stakeholders like engineers and administrators for proper maintenance and smooth traffic flow between Chamba and Bharmour cities, which is the only route connecting these tourist places. 展开更多
关键词 Information value Analytical Hierarchy Process Landslide hazard zonation GIS Remote sensing HIMALAYA
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An Iterative Decoding Scheme for Davey-MacKay Construction 被引量:5
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作者 Yuan Liu Weigang Chen 《China Communications》 SCIE CSCD 2018年第6期187-195,共9页
In the Davey-MacKay(DM) construction,the inner decoder treats unknown transmitted bits as random independent substitution errors. It limits the synchronization capability of the inner decoder, and thus weakens the err... In the Davey-MacKay(DM) construction,the inner decoder treats unknown transmitted bits as random independent substitution errors. It limits the synchronization capability of the inner decoder, and thus weakens the error-correcting capability of the DM construction.In order to improve the performance of the DM construction, an iterative decoding scheme is proposed, which iteratively utilizes the more accurate estimates of transmitted codewords. In the proposed scheme, the estimated average bit error rates and the estimated low-density parity-check(LDPC) codewords from the outer decoder are fed back into the inner decoder to update the synchronization process. Simulation results show that the proposed iterative decoding scheme significantly outperforms the traditional DM construction. 展开更多
关键词 Davey-MacKay construction iterative decoding LDPC code synchronization error
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Practical Polar Code Construction For Degraded Multiple-Relay Networks 被引量:2
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作者 Bin Duo Xiaoling Zhong Yong Guo 《China Communications》 SCIE CSCD 2017年第4期127-139,共13页
In this paper, based on the characteristics of polar codes, a new decode-and-forward strategy called generalized partial information relaying protocol is proposed for degraded multiple-relay networks with orthogonal r... In this paper, based on the characteristics of polar codes, a new decode-and-forward strategy called generalized partial information relaying protocol is proposed for degraded multiple-relay networks with orthogonal receiver components(MRNORCs). In such a protocol, with the help of partial information from previous nodes, each relay node tries to recover the received source message and re-encodes part of the decoded message for transmission to satisfy the decoding requirements for the following relay node or the destination node. In order to construct practical polar codes, the nested structures are developed based on this protocol and the information sets corresponding to the partial messages forwarded are also calculated. The proposed scheme is proved to be capable of achieving the theoretical capacity of the degraded MRN-ORCs while still retains the low-complexity feature of polar codes. We perform simulations to testify the practicability of the proposed scheme and compare polar codes by using successive-cancellation list decoder(SCLD) with traditional low-density parity-check(LDPC) codes. The results show that the obtained polar codes provide significant gain. 展开更多
关键词 cooperative communication multiple-relay networks channel capacity decode-and-forward polar codes
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Quantum-Mechanical Study of Small Au2Pdn (n=1 ~ 4) Clusters
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作者 GUO Jian-Jun YANG Ji-Xian DIE Dong 《Communications in Theoretical Physics》 SCIE CAS CSCD 2006年第1X期155-160,共6页
Gold-doped palladium clusters, Au2Pdn (n=1~4), are investigated using the density functional method B3LYP with relativistic effective core potentials (RECP) and LANL2DZ basis set. The possible geometrical configu... Gold-doped palladium clusters, Au2Pdn (n=1~4), are investigated using the density functional method B3LYP with relativistic effective core potentials (RECP) and LANL2DZ basis set. The possible geometrical configurations with their electronic states are determined, and the stability trend is investigated. Several low-lying isomers are determined, and many of them are in electronic configurations with a high-spin multiplicity. Our results indicate that the palladium-gold interaction is strong enough to modify the known pattern of bare palladium clusters, and the lower stability as the structures grow in size. The present calculations are useful to understanding the enhanced catalytic activity and selectivity gained by using gold-doped palladium catalyst. 展开更多
关键词 Au-Pd clusters geometrical configuration density functional method
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g factors of nuclear low-lying states:A covariant description 被引量:5
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作者 YAO JiangMing PENG Jing +1 位作者 MENG Jie RING Peter 《Science China(Physics,Mechanics & Astronomy)》 SCIE EI CAS 2011年第2期198-203,共6页
The g factors and spectroscopic quadrupole moments of low-lying excited states 2+1,…,81+ in 24Mg are studied in a covariant density functional theory.The wave functions are constructed by configuration mixing of axia... The g factors and spectroscopic quadrupole moments of low-lying excited states 2+1,…,81+ in 24Mg are studied in a covariant density functional theory.The wave functions are constructed by configuration mixing of axially deformed mean-field states projected on good angular momentum.The mean-field states are obtained from the constraint relativistic point-coupling model plus BCS calculations using the PC-F1 parametrization for the particle-hole channel and a density-independent delta-force for the particle-particle channel.The available experimental g factor and spectroscopic quadrupole moment of 21+ state are reproduced quite well.The angular momentum dependence of g factors and spectroscopic quadrupole moments,as well as the effects of pairing correlations are investigated. 展开更多
关键词 covariant density functional theory magnetic moment g factor spectroscopic quadrupole moment
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Construction method of QC-LDPC codes based on multiplicative group of finite field in optical communication 被引量:3
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作者 黄胜 敖翔 +1 位作者 李媛媛 张睿 《Optoelectronics Letters》 EI 2016年第5期349-352,共4页
In order to meet the needs of high-speed development of optical communication system, a construction method of quasi-cyclic low-density parity-check(QC-LDPC) codes based on multiplicative group of finite field is prop... In order to meet the needs of high-speed development of optical communication system, a construction method of quasi-cyclic low-density parity-check(QC-LDPC) codes based on multiplicative group of finite field is proposed. The Tanner graph of parity check matrix of the code constructed by this method has no cycle of length 4, and it can make sure that the obtained code can get a good distance property. Simulation results show that when the bit error rate(BER) is 10-6, in the same simulation environment, the net coding gain(NCG) of the proposed QC-LDPC(3 780, 3 540) code with the code rate of 93.7% in this paper is improved by 2.18 dB and 1.6 dB respectively compared with those of the RS(255, 239) code in ITU-T G.975 and the LDPC(3 2640, 3 0592) code in ITU-T G.975.1. In addition, the NCG of the proposed QC-LDPC(3 780, 3 540) code is respectively 0.2 dB and 0.4 dB higher compared with those of the SG-QC-LDPC(3 780, 3 540) code based on the two different subgroups in finite field and the AS-QC-LDPC(3 780, 3 540) code based on the two arbitrary sets of a finite field. Thus, the proposed QC-LDPC(3 780, 3 540) code in this paper can be well applied in optical communication systems. 展开更多
关键词 multiplicative parity codes subgroups arbitrary correction decoding iteration selecting iterative
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Quantum Discord in Two-Qubit System Constructed from the Yang-Baxter Equation
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作者 GOU Li-Dan WANG Xiao-Qian +1 位作者 XU Yu-Mei SUN Yuan-Yuan 《Communications in Theoretical Physics》 SCIE CAS CSCD 2014年第3期349-353,共5页
Quantum correlations among parts of a composite quantum system are a fundamental resource for several applications in quantum information. In general, quantum discord can measure quantum correlations. In that way,we i... Quantum correlations among parts of a composite quantum system are a fundamental resource for several applications in quantum information. In general, quantum discord can measure quantum correlations. In that way,we investigate the quantum discord of the two-qubit system constructed from the Yang–Baxter Equation. The density matrix of this system is generated through the unitary Yang–Baxter matrix R. The analytical expression and numerical result of quantum discord and geometric measure of quantum discord are obtained for the Yang–Baxter system. These results show that quantum discord and geometric measure of quantum discord are only connect with the parameter θ,which is the important spectral parameter in Yang–Baxter equation. 展开更多
关键词 quantum correlations quantum discord Yang-Baxter equation
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A novel construction method of QC-LDPC codes based on CRT for optical communications
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作者 袁建国 梁梦琪 +2 位作者 王永 林金朝 庞宇 《Optoelectronics Letters》 EI 2016年第3期208-211,共4页
A novel construction method of quasi-cyclic low-density parity-check(QC-LDPC) codes is proposed based on Chinese remainder theory(CRT). The method can not only increase the code length without reducing the girth, but ... A novel construction method of quasi-cyclic low-density parity-check(QC-LDPC) codes is proposed based on Chinese remainder theory(CRT). The method can not only increase the code length without reducing the girth, but also greatly enhance the code rate, so it is easy to construct a high-rate code. The simulation results show that at the bit error rate(BER) of 10^(-7), the net coding gain(NCG) of the regular QC-LDPC(4 851, 4 546) code is respectively 2.06 dB, 1.36 dB, 0.53 dB and 0.31 dB more than those of the classic RS(255, 239) code in ITU-T G.975, the LDPC(32 640, 30 592) code in ITU-T G.975.1, the QC-LDPC(3 664, 3 436) code constructed by the improved combining construction method based on CRT and the irregular QC-LDPC(3 843, 3 603) code constructed by the construction method based on the Galois field(GF(q)) multiplicative group. Furthermore, all these five codes have the same code rate of 0.937. Therefore, the regular QC-LDPC(4 851, 4 546) code constructed by the proposed construction method has excellent error-correction performance, and can be more suitable for optical transmission systems. 展开更多
关键词 准循环LDPC码 构造方法 CRT 光通信 密度奇偶校验码 代码率 ITU-T 阴极射线管
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Construction of Coarse-Grained Models by Reproducing Equilibrium Probability Density Function
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作者 吕世靖 周昕 《Communications in Theoretical Physics》 SCIE CAS CSCD 2015年第1期10-18,共9页
The present work proposes a novel methodology for constructing coarse-grained (CG) models, which aims at minimizing the difference between CG model and the corresponding original system. The difference is defined as... The present work proposes a novel methodology for constructing coarse-grained (CG) models, which aims at minimizing the difference between CG model and the corresponding original system. The difference is defined as a functional of their equilibrium conformationaJ probability densities, then is estimated from equilibrium averages of many independent physical quantities denoted as basis functions. An orthonormalization strategy is adopted to get the independent basis functions from su^ciently preselected interesting physical quantities of the system. Thus the current method is named as probability density matching coarse-graining (PMCG) scheme, which effectively takes into account the overall cha,~acteristics of the original systems to construct CG model, and it is a rtatural improvement of the usual CG scheme wherein some physical quantities are intuitively chosen without considering their correlations. We verify the general PMCG framework in constructing a one-site CG water model from TIP3P model. Both structure of liquids and pressure of the TIP3P water system are found to be well reproduced at the same time in the constructed CG model. 展开更多
关键词 coarse-graining models probability density functions molecular dynamics simulations
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A novel construction scheme of QC-LDPC codes based on the RU algorithm for optical transmission systems
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作者 袁建国 梁梦琪 +2 位作者 王永 林金朝 庞宇 《Optoelectronics Letters》 EI 2016年第2期132-135,共4页
A novel lower-complexity construction scheme of quasi-cyclic low-density parity-check(QC-LDPC) codes for optical transmission systems is proposed based on the structure of the parity-check matrix for the Richardson-Ur... A novel lower-complexity construction scheme of quasi-cyclic low-density parity-check(QC-LDPC) codes for optical transmission systems is proposed based on the structure of the parity-check matrix for the Richardson-Urbanke(RU) algorithm. Furthermore, a novel irregular QC-LDPC(4 288, 4 020) code with high code-rate of 0.937 is constructed by this novel construction scheme. The simulation analyses show that the net coding gain(NCG) of the novel irregular QC-LDPC(4 288,4 020) code is respectively 2.08 d B, 1.25 d B and 0.29 d B more than those of the classic RS(255, 239) code, the LDPC(32 640, 30 592) code and the irregular QC-LDPC(3 843, 3 603) code at the bit error rate(BER) of 10^(-6). The irregular QC-LDPC(4 288, 4 020) code has the lower encoding/decoding complexity compared with the LDPC(32 640, 30 592) code and the irregular QC-LDPC(3 843, 3 603) code. The proposed novel QC-LDPC(4 288, 4 020) code can be more suitable for the increasing development requirements of high-speed optical transmission systems. 展开更多
关键词 classic codes parity decoding encoding irregular Richardson correction iteration triangular
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