检索结果-南通市图书馆

Earthquake research in China 2007年第3期21卷 281-292页

作者： Pan Bo Xu Jiandong Haruko Sekigguchi He Honglin Institute of Geology China Earthquake Administration Beijing 100029 China active fault research center Tsukuba Ibaraki 305-8567 Japan

On the basis of previous study of the 1679 Sanhe-Pinggu(M8.0) earthquake,the biggest event in history ever recorded in Beijing and its adjacent area,we made a 3-D strong ground motion simulation utilizing the staggered-grid finite differences method to study the distributions of peak ground velocity with different earthquake source models in the Beijing *** the paper,earthquake source models and a transmission medium velocity model are established and the corresponding parameters are given in accordance to the results from a related previous ***,using a three-dimensional finite difference computing program of near-fault strong ground motion developed by Graves,the peak ground velocity caused by a destructive earthquake in the Beijing area is *** our computation model,the earthquake source is 3km in depth,and a total number of 21,679 observation points on the ground surface are figured *** transmission medium velocity model is composed of four stratums which are the Quaternary deposit,the upper crust,the upper part of the middle crust and the lower part of the middle *** the minimum grid spacing of 0.15km,a total of 2.28×106 grids are *** a time step of 0.02 seconds we calculated the peak ground velocity for a duration of 8 *** the analysis of the simulation results,we observed some basic characteristics of near-fault strong ground motion such as the concentration effect of near-fault peak ground velocity,rupture directivity effect,hanging wall effect,and basin *** results from our simulation and analysis suggest that the source and transmitting medium parameters in our model are suitable and the finite difference method is applicable to estimate the distribution of strong ground motion in the study region.

关键词： Strong ground motion Source parameter Transmitting medium parameter Concentration effect Rupture directivity effect Hanging wall effect, basin effect

An effective method for laboratory acoustic emission detection and location using template matching

在线全文

学校读者我要写书评

暂无评论

Journal of Rock Mechanics and Geotechnical Engineering 2022年第5期14卷 1642-1651页

作者： Xinglin Lei Tomohiro Ohuchi Manami Kitamura Xiaying Li Qi Li National Institute of Advanced Industrial Science and Technology(aist) Tsukuba305-8567Japan Geodynamics research center Ehime UniversityMatsuyama790-8577Japan State Key Laboratory of Geomechanics and Geotechnical Engineering Institute of Rock and Soil MechanicsChinese Academy of SciencesWuhan430071China University of Chinese Academy of Sciences Beijing100049China

In this paper, a template matching and location method, which has been rapidly adopted in microseismic research in recent years, is applied to laboratory acoustic emission(AE) monitoring. First, we used traditional methods to detect P-wave first motions and locate AE hypocenters in three dimensions. In addition, we selected events located with sufficient accuracy(normally corresponding AE events of relatively larger energy, showing clear P-wave first motion and a higher signal-to-noise ratio in most channels) as template events. Then, the template events were used to scan and match other poorly located events in triggered event records or weak events in continuous records. Through crosscorrelation of the multi-channel waveforms between the template and the event to be detected, the weak signal was detected and located using a grid-searching algorithm(with the grid centered at the template hypocenter). In order to examine the performance of the approach, we calibrated the proposed method using experimental data of different rocks and different types of experiments. The results show that the proposed method can significantly improve the detection capability and location accuracy, and can be applied to various laboratory and in situ experiments, which use multi-channel AE monitoring with waveforms recorded in either triggering or continuous mode.

关键词： Acoustic emission Template matching and location Waveform cross-correlation Grid search

Geochemical and Grain-Sized Implications for Provenance Variations of the Central Yellow Sea Muddy Area Since the Middle Holocene

在线全文

学校读者我要写书评

暂无评论

Journal of Ocean University of China 2020年第3期19卷 577-588页

作者： AI Lina HAN Zongzhu WU Xiao SAITO Yoshiki WANG Houjie College of Marine Geosciences/Key Laboratory of Submarine Geosciences and Prospecting Techniques MOEOcean University of ChinaQingdao 266100China Laboratory of Marine Geology Qingdao National Laboratory of Marine Science and TechnologyQingdao 266237China Estuary research center Shimane UniversityMatsue 690-8504Japan Geological Survey of Japan AISTTsukuba 305-8567Japan

Based on high-resolution analysis to a 280-cm long sediment core obtained from the muddy area in the central Yellow Sea, we examined the provenance of muddy sediments and discussed the changing marine sedimentary environment since the middle Holocene. The results indicated that fine-grained sediments in the muddy area were mainly derived from the Huanghe(Yellow River) and Changjiang(Yangtze River) with considerable stepwise variations during the past 6.6 kyr. The Yellow Sea Warm Current was initiated at 6 kyr when the sea level was high together with the enhanced East Asian Winter Monsoon. These in combination established the framework of shelf circulation in the Yellow Sea that began to trap the river-derived fine-grained sediments. From 4.9 kyr to 2.8 kyr, both the Kushiro Current and East Asian Monsoon were significantly weakened, reducing the delivery of Changjiang sediments to the muddy area. As a result, the sediments were mainly originated from the Huanghe. From 2.8 kyr to 1.5 kyr the continuously weakened East Asian Winter Monsoon and enhanced Yellow Sea Warm Current entrapped more fine-grain sediments. Whereas the enhanced East Asian Winter Monsoon and the human caused increase in sediment load of the Huanghe since 1.5 kyr, and direct delivery of Huanghe sediments to the Yellow Sea during 1128–1855 AD might dominated the sedimentation in the study area. The stepwise variations of the sediment provenance and composition of the Central Yellow Sea muddy sediments are of importance to understanding the formation of muddy deposit in the central Yellow Sea and the associated variations of marine environment since the middle Holocene.

关键词： sediment provenance rare earth elements grain size central Yellow Sea mud middle Holocene

Zircon U–Pb geochronology and Hf isotope geochemistry of magmatic and metamorphic rocks from the Hida Belt, southwest Japan

在线全文

学校读者我要写书评

暂无评论

Geoscience Frontiers 2021年第4期12卷 185-201页

作者： Deung-Lyong Cho Tae-Ho Lee Yutaka Takahashi Takenori Kato Keewook Yi Shinae Lee Albert Chang-sik Cheong Korea Institute of Geoscience and Mineral Resources Daejeon 34132Republic of Korea Geological Survey of Japan Tsukuba 305-8567Japan Institute for Space-Earth Environmental research Nagoya UniversityNagoya 464-8601Japan Korea Basic Science Institute Ochang center Cheongju 28119Republic of Korea

Zircon U–Pb and Hf isotope data integrated in this study for magmatic and metamorphic rocks fromthe Hida Belt,southwest Japan,lead to a new understanding of the evolution of the Cordilleran arc system along the ancestral margins of present-day Northeast *** microprobe data for magmatic zircon domains from eight mafic tointermediate orthogneisses in the Tateyama and Tsunogawa areas yielded weighted mean 206Pb/238U ages spanning the entire Permian period(302–254 Ma).Under cathodoluminescence,primary magmatic growth zones in the zircon crystals were observed to be partially or completely replaced by inward-penetrating,irregularly curved featureless or weakly zoned secondary domains that mostly yielded U–Pb ages of 250–240 Ma and relatively high Th/U ratios(>0.2).These secondary domains are considered to have been formed by solid-state recrystallization during thermal overprints associated with intrusions of Hida *** whole-rock geochemical and Sr–Nd isotope data as well as zircon age spectra corroborate that the Hida Belt comprises the Paleozoic–Mesozoic Cordilleran arc system built upon the margin of the North China Craton,together with the YeongnamMassif in southern *** arcmagmatismalong this systemwas commenced in the Carboniferous and culminated in the Permian–Triassic transition *** positiveεHf(t)values(>+12)of late Carboniferous to early Permian detrital zircons in the Hida paragneisses indicate that there was significant input from the depleted asthenospheric mantle and/or its crustal derivatives in the early stage of arc *** the other hand,near-chondriticεHf(t)values(+5 to−2)of magmatic zircons from late Permian Hida orthogneisses suggest a lithospheric mantle *** isotopic differences between magmatic zircon cores and the secondary rims observed in some orthogneiss samples clearly indicate that the zircons were chemically open to fluids or melts during thermal *** highly positive zirconεHf(t)val

关键词： Hida Belt Zircon U–Pb age Hf isotope Cordilleran arc Yeongnam Massif

A hierarchical enhanced data-driven battery pack capacity estimation framework for real-world operating conditions with fewer labeled data

在线全文

学校读者我要写书评

暂无评论

Journal of Energy Chemistry 2024年第4期91卷 417-432页

作者： Sijia Yang Caiping Zhang Haoze Chen Jinyu Wang Dinghong Chen Linjing Zhang Weige Zhang National active Distribution Network Technology research center(NANTEC) Beijing Jiaotong UniversityBeijing 100044China

Battery pack capacity estimation under real-world operating conditions is important for battery performance optimization and health management,contributing to the reliability and longevity of batterypowered ***,complex operating conditions,coupling cell-to-cell inconsistency,and limited labeled data pose great challenges to accurate and robust battery pack capacity *** address these issues,this paper proposes a hierarchical data-driven framework aimed at enhancing the training of machine learning models with fewer labeled *** traditional data-driven methods that lack interpretability,the hierarchical data-driven framework unveils the“mechanism”of the black box inside the data-driven framework by splitting the final estimation target into cell-level and pack-level intermediate targets.A generalized feature matrix is devised without requiring all cell voltages,significantly reducing the computational cost and memory *** generated intermediate target labels and the corresponding features are hierarchically employed to enhance the training of two machine learning models,effectively alleviating the difficulty of learning the relationship from all features due to fewer labeled data and addressing the dilemma of requiring extensive labeled data for accurate *** only 10%of degradation data,the proposed framework outperforms the state-of-the-art battery pack capacity estimation methods,achieving mean absolute percentage errors of 0.608%,0.601%,and 1.128%for three battery packs whose degradation load profiles represent real-world operating *** high accuracy,adaptability,and robustness indicate the potential in different application scenarios,which is promising for reducing laborious and expensive aging experiments at the pack level and facilitating the development of battery technology.

关键词： Lithium-ion battery pack Capacity estimation Label generation Multi-machine learning model Real-world operating

Rupture segmentation and slip partitioning of the mid-eastern part of the Kunlun fault,north Tibetan Plateau

在线全文

学校读者我要写书评

暂无评论

Science China Earth Sciences 2011年第11期54卷 1730-1745页

作者： LI ChenXia XU XiWei WEN XueZe ZHENG RongZhang CHEN GuiHua YANG Hu AN YanFen GAO Xiang Institute of Geology China Earthquake Administration National Center of Active Fault Studies Beijing 100029 China Lanzhou Seismological Institute of China Earthquake Administration Lanzhou 730000 China Earthquake Administration of Sichuan Province Chengdu 610041 China

The Kunlun fault, an active fault on the border between the Bayan Har and Kunlun-Qaidam blocks, is one of the major left lateral strike-slip faults in the Tibetan Plateau. Previous research has not reached a consensus on agreeable slip rates along much of its length and the slip rate gradient along the eastern part, both of which play critical roles in a range of models for the eastward extrusion and thickened crust of the Tibetan Plateau. New slip rates have been determined at sites along the eastern part of the Kunlun fault by dating deposits and measuring atop displaced fluvial terrace risers. Field investigations and interpretation of satellite images reveal geometrical features of the fault and the late Quaternary offset, new earthquake ruptures and surface-rupturing segmentation, from which long-term slip rates and earthquake recurrence intervals on the fault are estimated. The tectonic geomorphology method has determined that the long-term horizontal slip rates on the Tuosuohu, Maqin and Ma- qu segments from west to east are 11.2±1, 9.3±2, and 4.9±1.3 mm/a while their vertical slip rates are 1.2±0.2, 0.7±0.1, and 0.3 mm/a in the late Quaternary. Results indicate that the slip rates regularly decrease along the eastern -300 km of the fault from 〉10 to 〈5 mm/a. This is consistent with the decrease in the gradient such that at the slip rate break point is at the triple point intersection with the transverse fault, which in turn is transformed to the Awancang fault. The vector decomposition for this tectonic transformation shows that the western and eastern branches of the Awancang fault fit the slip-partitioning mode. The slip rate of the southwestern wall is 4.6 mm/a relative to the northeastern wall and the slip direction is 112.1°. The mid-eastern part of the Kunlun fault can be divided into three independent segments by the A＇nyemaqen double restraining bend and the Xigongzhou intersection zone, which compose the surface rupture segmentation indicators for t

关键词： mid-eastern Kunlun fault slip rate surface rupture segmentation slip partition paleoearthquake Tibetan Plateau

Optimal planning of energy storage system in active distribution system based on fuzzy multi-objective bi-level optimization

在线全文

学校读者我要写书评

暂无评论

Journal of Modern Power Systems and Clean Energy 2018年第2期6卷 342-355页

作者： Rui LI Wei WANG Zhe CHEN Xuezhi WU National active Distribution Network Technology research center Beijing Jiaotong University Department of Energy Technology Aalborg University

A fuzzy multi-objective bi-level optimization problem is proposed to model the planning of energy storage system(ESS) in active distribution systems(ADS). The proposed model enables us to take into account how optimal operation strategy of ESS in the lower level can affect and be affected by the optimal allocation of ESS in the upper level. The power characteristic model of micro-grid(MG)and typical daily scenarios are established to take full consideration of time-variable nature of renewable energy generations(REGs) and load demand while easing the burden of computation. To solve the bi-level mixed integer problem, a multi-subgroup hierarchical chaos hybrid algorithm is introduced based on differential evolution(DE) and particle swarm optimization(PSO). The modified IEEE-33 bus benchmark distribution system is utilized to investigate the availability and effectiveness of the proposed model and the hybrid algorithm. Results indicate that the planningmodel gives an adequate consideration to the optimal operation and different roles of ESS, and has the advantages of objectiveness and reasonableness.

关键词： active distribution system Energy storage system Optimal planning Bi-level programming Fuzzy multiple objective

利用小震震源机制解研究汶川地震后龙门山断裂带中段应力场时空演化

在线全文

学校读者我要写书评

暂无评论

地震地质 2018年第2期40卷 310-322页

作者：江敏陈九辉 Yasuto Kuwahara Reiken Matsushita 中国地震局地质研究所、地震动力学国家重点实验室北京100029 active fault and Earthquake research center AISTJapan

利用川西流动地震台阵观测资料,求解汶川地震后发生在龙门山断裂带中段地区的余震震源机制解,反演了相应的应力场,得到了应力场的时空演化特征。结果显示,小震震源机制以逆冲为主并含有一定数量的走滑和正断型地震,逆冲型地震的比重随... 详细信息

利用川西流动地震台阵观测资料,求解汶川地震后发生在龙门山断裂带中段地区的余震震源机制解,反演了相应的应力场,得到了应力场的时空演化特征。结果显示,小震震源机制以逆冲为主并含有一定数量的走滑和正断型地震,逆冲型地震的比重随时间明显增加。震源机制类型的空间分布与断层深部展布及区域速度结构具有相关性。应力张量反演结果显示早期余震各分区水平最大主压应力S_H方位主要分布在近EW—NWW范围内,沿小鱼洞—理县方向余震分支地壳浅部主压应力则沿NE-SW向,表明震后早期应力场主要受主震破裂传播引起的动态应力影响,S_H方位与破裂面特征密切相关。应力张量随时间的变化显示深部应力结构由逆冲、走滑混合向纯逆冲转变,表明深部区域通过走滑型地震来平衡初期应力释放造成的局部库仑应力,并逐渐恢复到接近背景应力场,浅部应力变化追随深部变化特征,显示出在时间上的滞后。

关键词：龙门山断裂带震源机制应力场时空演化

Designed fabrication of active tumor targeting covalent organic framework nanotherapeutics via a simple post-synthetic strategy

在线全文

学校读者我要写书评

暂无评论

Nano research 2023年第5期16卷 7085-7094页

作者： Yue Yu Guoxin Zhang Zhongping Li Jia Wang Yang Liu Rahul Bhardwaj Renu Wadhwa Yuki Nagao Mototada Shichiri Ran Gao Biomedical research Institute National Institute of Advanced Industrial Science and Technology(AIST)Osaka 563-8577Japan aist-INDIA DAILAB DBT-AIST International Center for Translational&Environmental Research(DAICENTER)AISTTsukubaIbaraki 305-8565Japan Beijing Engineering research center for Experimental Animal Models of Human Critical Diseases NHC Key Laboratory of Human Disease Comparative MedicineNational Human Diseases Animal Model Resource CenterInstitute of Laboratory Animal ScienceChinese Academy of Medical Sciences(CAMS)&Peking Union Medical CollageBeijing 100021China School of Materials Science Japan Advanced Institute of Science and TechnologyIshikawa 923-1211Japan Department of Chemical and Biomolecular Engineering Yonsei University50 Yonsei-roSeodaemun-guSeoul 120-749Republic of Korea Flexible 3D System Integration Laboratory SANKENOsaka UniversityOsaka 567-0047Japan

Developing agents that can accurately differentiate tumors from normal healthy tissues is of utmost importance for safe cancer *** targeting has been considered as an effective technique for tumor *** this work,we demonstrate a folate-functionalized nanoscale covalent organic framework(FATD nCOF)highly specific to cancer cells through active targeting of their enriched folate receptors(FRs).The FATD nCOF prepared by simple post-synthetic modification of the COF surface defeats disperses well in water and exhibits a high loading capacity for various anticancer *** biocompatible FATD nCOF is selectively internalized by FR-harboring cancer cells and consequently augments the efficacy of the loaded drug,Withaferin A(Wi-A),for targeted cancer cell *** biomolecular mechanism studies,Wi-A-loaded FATD(FATD@Wi-A)nanocomposites show remarkably a higher rate of apoptosis in FR-enriched cancer *** analyses of FR-positive and FR-negative tumor xenografts reveal enhanced selective antitumor activity of FATD@Wi-A *** together,the study findings suggest that FATD nCOF holds great promise for active targeting of tumors in *** simple yet effective technology might be valuable for creating new state-of-the-art COFs for chemical and biomedical applications.

关键词： covalent organic framework active targeting folate receptor drug delivery cancer therapy