检索结果-南通市图书馆

Science China Earth Sciences 2023年第10期66卷 2395-2398页

作者： yong Zheng State Key Laboratory of Geological Processes and Mineral Resources School of Geophysics and GeomaticsChina University of GeosciencesWuhan430074China Hubei Subsurface Multi-Scale Imaging Key Laboratory Wuhan430074China

1.Significance of the Southwest China community velocity model(SWChina CVM),As a result of the collision between the Indian and Eurasian Plates,crustal materials in the Tibetan Plateau extrude southeastward,leading to... 详细信息

关键词： seismic crustal Eurasian

Earthquake potential of the seismic gap between the Wenchuan and Lushan earthquakes:Current status,thoughts,and challenges

在线全文

学校读者我要写书评

暂无评论

Science China Earth Sciences 2021年第3期64卷 503-506页

作者： yong Zheng Rumeng GUO State Key Laboratory of Geological Processes and Mineral Resources Institute of Geophysics and GeomaticsChina University of Geosciences(Wuhan)Wuhan430074China Earth System Science Programme The Chinese University of Hong KongHong Kong999077China Institute of Precision Measurement Science and Technology Innovation Chinese Academy of SciencesWuhan430071China College of Earth and Planetary Sciences University of Chinese Academy of SciencesBeijing100049China

1.Background on the seismic gap between the Wenchuan and the Lushan earthquakes The 2008 Mw7.9 Wenchuan earthquake and the 2013 Mw6.9 Lushan earthquake,which occurred in the Longmenshan fault system(hereafter called LMSFS),caused dramatically casualties and huge economic losses.Their aftershock zones outline a seismic gap of about 50 km(Figure 1).

关键词： seismic earthquake fault

Study on Acoustic Performance for Diatom Frustule with Nanoporous Structure

在线全文

学校读者我要写书评

暂无评论

Journal of Bionic Engineering 2023年第4期20卷 1656-1669页

作者： Fanming Meng yong Zheng Hongxia Wang Lin Chen College of Mechanical Engineering Hubei University of Automotive TechnologyShiyan442002China State Key Laboratory of Mechanical Transmission Chongqing UniversityChongqing400044China

The acoustic performance for the nanoporous frustule of the diatom is studied based on the computational fluid dynamics theory and acoustic theory involved.Representative Coscinodiscus sp.frustule is observed through the scanning electron microscope and modeled by the commercial software Solidworks.Further,the acoustic performance for the Coscinodiscus sp.frustule is studied at the varied depth,diameter or interval of the pore,as well as the film thickness of the fluid surrounding the Coscinodiscus sp.frustule.The numerical results show that,when the upper and lower pore diameters are separately 200 and 300 nm,the upper and lower pore depths are separately 200 and 250 nm,and both the pore interval and fluid film thickness are 500 nm,the elaborate nanoporous structure of Coscinodiscus sp.frustule can lower its acoustic power level by 17.49%,compared with that without porous structure.Meanwhile,the double-layer pore of Coscinodiscus sp.frustule can decrease its acoustic power level by 12.69%,compared with its single-layer pore structures.

关键词： Acoustic performance Nanoporous structure Diatom Computational fluid dynamics

Source characteristics of the mainshock and aftershocks of the 2019 Changning earthquake sequence:Implications for fluid effects

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Science China Earth Sciences 2023年第6期66卷 1321-1333页

作者： Kun DAI yong Zheng Rumeng GUO Jianqiao XU School of Physics Huazhong University of Science and TechnologyWuhan 430074China Innovation Academy for Precision Measurement Science and Technology Chinese Academy of SciencesWuhan 430071China State Key Laboratory of Geological Processes and Mineral Resources School of Geophysics and GeomaticsChina University of GeosciencesWuhan 430074China

The 2019 M_(S)6.0 Changning earthquake occurred in the tectonically stable Sichuan Basin,where the epicenter and its adjacent areas are important shale gas and salt mine production fields,resulting in hot debates on whether the seismogenic mechanism of the 2019 Changning earthquake is related to human activities.As source characteristics and fluid pressure can provide important constraints on whether an earthquake is induced,weinvestigate the seismogenic mechanisms of the mainshock and 9 MW≥4.0 aftershocks.In overall,the mainshock and the majority of the aftershocks are characterized by relatively shallow focal depths(1‒4 km)and significant non-double-couple(non-DC)components.However,the mainshock and the aftershocks differ in two aspects:(1)the compensated-linear-vector-dipole components dominate the non-DC components of the mainshock,whereas the isotropic components dominate the most aftershocks;(2)the fluid overpressure of the mainshock is over 30 MPa,whereas the fluid overpressure of the most aftershocks is less than 10 MPa.Thus,we propose that the mainshock is triggered by weakened fault strength with long-term fluid injection,and that its large non-DC components are associated withcomplex rupture processes.Comparatively,the aftershocks may be triggered by postseismic stress transfer by combining the Coulomb failure stress changes in the poroelastic medium.Our results highlight the possible role of fluid in the occurrence of the Changning earthquake sequence.

关键词： The 2019 Channing earthquake Induced earthquakes Non-double-couple components Focal depths Poroelasticity

Plate tectonics in the twenty-first century

在线全文

学校读者我要写书评

暂无评论

Science China Earth Sciences 2023年第1期66卷 1-40页

作者： yong-Fei zheng CAS Key Laboratory of Crust-Mantle Materials and Environments Hefei 230026China School of Earth and Space Sciences University of Science and Technology of ChinaHefei 230026China

Plate tectonics was originally established as a kinematic theory of global tectonics,in which the Earth’s rigid outer layer,the lithosphere,consists of different size plates that move relative to each other along divergent,convergent or transform boundaries overlying the ductile asthenosphere.It comprises three elements:rigid lithosphere plates,ductile asthenosphere,and coupled movement systems.It operates through the interlinked processes of continental drift,seafloor spreading and lithospheric subduction,resulting in the generation,modification and demise of lithospheres throughout geological time.The system of lithospheric plates in horizontal and vertical movements forms the spatiotemporal linkages of matter and energy between the surface and interior of Earth,advancing the kinematic theory with a dynamic explanation.While top-down tectonics through lithospheric subduction plays a key role in the operation of plate tectonics,it is balanced for the conservation of both mass and momentum on the spherical Earth by bottom-up tectonics through asthenospheric upwelling to yield seafloor spreading after continental breakup.The gravity-driven subduction of cool lithosphere proceeds through convergence between two plates on one side,and rollback of the subducting slab makes the vacancy for upwelling of the hotter asthenosphere to form active rifting in backarc sites.Plate convergence is coupled with plate divergence between two plates along mid-ocean ridges on the other side,inducing passive rifting for seafloor spreading as a remote effect.Thus,plate tectonics is recognizable in rock records produced by tectonic processes along divergent and convergent plate margins.Although the asthenospheric upwelling along fossil suture zones may result in continental breakup,seafloor spreading is only induced by gravitational pull of the subducting oceanic slab on the remote side.Therefore,the onset and operation of plate tectonics are associated with a series of plate divergent-convergent coupling systems,and they are critically

关键词： Continental breakup Seafloor spreading Oceanic subduction Continental collision Lithospheric thinning Asthenospheric upwelling

Simulation research on the energy dissipation and shock absorption performance of a swing column device based on fuzzy control

在线全文

学校读者我要写书评

暂无评论

Earthquake Engineering and Engineering Vibration 2022年第4期21卷 987-998页

作者： zheng yong Yuan Bo Research Center of Space Structures Guizhou UniversityGuiyang 550004China College of Civil Engineering Guizhou UniversityGuiyang 550004China Key Laboratory of Structural Engineering of Guizhou Province Guiyang 550025China

Double-column bridge piers are prone to local damage during earthquakes,leading to the destruction of bridges.To improve the earthquake resistance of double-column bridge piers,a novel swing column device(SCD),consisting of a magnetorheological(MR)damper,a current controller,and a swing column,was designed for the present work.To verify the seismic energy dissipation ability of the SCD,a lumped mass model for a double-column bridge pier with the SCD was established according to the low-order modeling method proposed by Steo.Furthermore,the motion equation of the double-column bridge pier with the SCD was established based on the D′Alembert principle and solved with the use of computational programming.It was found that the displacement response of the double-column bridge pier was effectively controlled by the SCD.However,due to rough current selection and a time delay,there is a significant overshoot of the bridge acceleration using SCD.Hence,to solve the overshoot phenomenon,a current controller was designed based on fuzzy logic theory.It was found that the SCD design based on fuzzy control provided an ideal shock absorption effect,while reducing the displacement and acceleration of the bridge pier by 36.43%‒40.63%and 30.06%‒33.6%,respectively.

关键词： swing column device double-column bridge pier fuzzy control MR damper structural control low-element modeling method

Investigations of Thermal Deformation Based on the Monitoring System of Tianma 13.2 m VGOS Telescope

在线全文

学校读者我要写书评

暂无评论

Research in Astronomy and Astrophysics 2022年第9期22卷 35-46页

作者： Shize Song Zhongkai Zhang Guangli Wang yong Zheng Shanghai Astronomical Observatory Chinese Academy of SciencesShanghai 20030China University of Chinese Academy of Sciences Beijing.100049China Information Engineering University Zhengzhou 450000China Henan Industrial Technology Academy of Spatio-Temporal Big Data Zhengzhou 450000China

The thermal expansion of radio telescopes has been recognized as a significant systematic error in Very Long Baseline Interferometry(VLBI) data analysis. Although the thermal expansion model recommended by International Earth Rotation Service(IERS) Conventions 2010 can achieve millimeter accuracy for the International VLBI Service for Geodesy and Astrometry(IVS) routine telescopes, both the International Terrestrial Reference Frame 2020(ITRF2020) in preparation and the VLBI2010 project encourage the scientific community to reconsider its modeling. To this end, we developed a monitoring system for the Tianma 13.2 m VLBI Global Observing System(VGOS) telescope. Based on the observed data, we refined the IERS expansion model, with results showing that the accuracy of our modified model was improved by 1.9 times. It suggested that the IERS thermal expansion model can achieve the declared millimeter accuracy, and refining its modeling can meet the requirement of 0.3 mm rms stability of the VGOS antenna reference point for the VLBI2010 project.

关键词： Astronomical Instrumentation Methods and Techniques methods:analytical methods:data analysis telescopes

Monkeypox,wild animals,and potential big problem

在线全文

学校读者我要写书评

暂无评论

Zoological Research 2022年第4期43卷 612-614页

作者： Tian-Zhang Song yong-Tang zheng Key Laboratory of Animal Models and Human Disease Mechanisms of the Chinese Academy of Sciences KIZ-CUHK Joint Laboratory of Bioresources and Molecular Research in Common DiseasesKunming Institute of ZoologyChinese Academy of SciencesKunmingYunnan 650223China National Resource Center for Non-Human Primates National Research Facility for Phenotypic&Genetic Analysis of Model Animals(Primate Facility)Kunming Institute of ZoologyChinese Academy of SciencesKunmingYunnan 650107China

A new outbreak of monkeypox virus(MPV)is currently occurring in several regions of the world.Since the beginning of May 2022,3040 cases have been reported to the World Health Organization(WHO)globally.Outside of its usual“endemic”base in Africa,the virus has so far been detected in 47 countries,including in Europe,America,Oceania,and Asia,where monkeypox is uncommon or previously unreported.On 25 June 2022,the WHO Emergency Committee declared that the outbreak does not currently constitute a Public Health Emergency of International Concern,but unanimously acknowledged the emergency nature of the event and that controlling further spread will require a vigorous response.Recently,new cases of MPV infection have been confirmed in Korea,Singapore,and Taiwan,China.Thus,a better understanding of MPV and enhanced surveillance are essential for preventing disease recurrence.

关键词： globally Taiwan currently

An integrated north–south paleo-Dadu-Anning River: New insights from bulk major and trace element analyses of the Xigeda Formation

在线全文

学校读者我要写书评

暂无评论

China Geology 2024年第1期7卷 91-103页

作者： yong Zheng Hai-bing Li Jia-wei Pan Ping Wang Ya Lai zheng Gong Key Laboratory of Deep-Earth Dynamics Institute of GeologyChinese Academy of Geological SciencesChina Geological SurveyMinistry of Natural ResourcesBeijing 100037China Jiangsu Donghai Continental Deep Hole Crustal Activity National Observaion and Research Station Lianyungang 222300China Southern Marine Science and Engineering Guangdong Laboratory Guangzhou 511458China Geophysical Exploration Center China Earthquake AdministrationZhengzhou 450002China Institute of Geophysics China Earthquake AdministrationBeijing 100081China

The Xianshuihe-Anninghe fault extends SE–S and constitutes the southeastern margin of the Tibetan Plateau.However,the Dadu River which is associated with the fault does not flow following the path,but makes a 90ºturn within a distance of 1 km at Shimian,heading east,and joins the Yangtze River,finally flowing into the East China Sea.Adjacent to the abrupt turn,a low and wide pass near the Daqiao reservoir at Mianning separates the N–S course of the Dadu River from the headwater of the Anning River which then flows south into the Yunnan Province along the Anninghe fault.Therefore,many previous studies assumed southward flow of the paleo-Dadu River from the Shimian to the Anning River.However,evidences for the capture of the integrated N–S paleo-Dadu-Anning River,its timing,and causes are still insufficient.This study explored the paleo-drainage pattern of the Dadu and Anning Rivers based on bulk mineral and geochemical analyses of the large quantities of fluvial/lacustrine sediments along the trunk of the Dadu and Anning Rivers.Similar with sands in the modern Dadu River,the Xigeda sediments also exhibit a granitoid affinity with the bulk major mineral compositions of quartz(>50%),anorthite(about 10%),orthoclase(about 5%),muscovite(about 5%),and clinochlore(about 4%).Correspondingly,bulk major elements show high SiO_(2),with all samples>60%,and some of them>70%,low TiO_(2)(≤0.75%),P_(2)O_(5)(≤0.55%),FeO*(≤5%),and relatively high CaO(1.02%–8.51%),Na_(2)O(1.60%–2.52%),and K_(2)O(2.17%–2.71%),with a uniform REE patterns.Therefore,synthesizing all these results indicate that these lacustrine sediments have similar material sources,which are mainly derived from its course in the Songpan-Ganzi flysch block,implying that the paleo-Dadu originally flowed southward into the Anning River and provided materials to the Xigeda ancient lake.The rearrangement of the paleo-Dadu River appears to be closely related to the locally focused uplift driven by strong activities of the XianshuiheXiaojiang fault system.

关键词： Dadu River Anninghe fault River diversion Xigeda Formation Tectonic uplift Provenance Songpan-Ganzi flysch Ancient lake Xianshuihe-Xiaojiang fault system Tibetan Plateau

ZR and ZRDC embrace a new era

在线全文

学校读者我要写书评

暂无评论

Zoological Research 2023年第1期44卷 1-2页

作者： yong-Gang Yao yong-Tang zheng Kunming Institute of Zoology Chinese Academy of SciencesKunmingYunnan 650223China

Since its establishment in 1980, Zoological Research(ZR) has continued to strive forward with the enthusiastic and generous support of every author and reader. ZR has been a loyal companion to many generations of researchers and scholars,who have not only witnessed the evolution of ZR, but also devoted themselves to helping ZR grow(Yao & Jiang, 2021).Here, at the beginning of a fresh year, we are honored to have the opportunity to express our deepest appreciation to you all.

关键词： devoted continued evolution