This is a review of the formation and tectonic evolution of the continental Asia in Phanerozoic.The continental Asia has formed on the bases of some pre-Cambrian cratons,such as the Siberia,India,Arabia,North China,Ta...This is a review of the formation and tectonic evolution of the continental Asia in Phanerozoic.The continental Asia has formed on the bases of some pre-Cambrian cratons,such as the Siberia,India,Arabia,North China,Tarim,South China,and Indochina,through multi-stage plate convergence and collisional collages in Phanerozoic.The north-central Asia had experienced the expansion and subduction of the Paleo-Asian Ocean(PAO)in the early Paleozoic and the closure of the PAO in the late Paleozoic and early Mesozoic,forming the PAO regime and Central Asian orogenic belt(CAOB).In the core of the CAOB,the Mongol-Okhotsk Ocean(MOO)opened with limited expansion in the Early Permian and finally closed in the Late Jurassic–Early Cretaceous.The south-central Asia had experienced mainly multi-stage oceanic opening,subduction and collision evolution in the Tethys Ocean,forming the Tethys regime and Himalaya-Tibetan orogenic belt.In eastern Asia,the plate subduction and continental margin orogeny on western margin of the Pacific Ocean,forms the West Pacific regime and West Pacific orogenic belt.The PAO,Tethys,and West Pacific regimes,together with Precambrian cratons among or surrounding them,made up the major tectonic and dynamic systems of the continental Asia in Phanerozoic.Major tectonic events,such as the Early Paleozoic Qilian,Uralian,and Dunhuang orogeneses,the late Paleozoic East Junggar,Tianshan and West Junggar orogeneses,the Middle to Late Permian Ailaoshan orogeny and NorthSouth Lhasa collision,the early Mesozoic Indochina-South China and North-South China collisions,the late Mesozoic Mongolia-Okhotsk orogeny,Lhasa-Qiangtang collision,and intra-continental Yanshanian orogeny,and the Cenozoic IndoAsian,Arab-Asian,and West Pacific margin collisions,constrained the formation and evolution of the continental Asia.The complex dynamic systems have left large number of deformation features,such as large-scale strike-slip faults,thrustfold systems and extensional detachments on the continental Asia.Based on past tectonics,a f展开更多
The West Junggar of the western Central Asian Orogenic Belt is one of the typical regions in the term of ocean subduction, contraction and continental growth in the Late Paleozoic. However, it is still controversial o...The West Junggar of the western Central Asian Orogenic Belt is one of the typical regions in the term of ocean subduction, contraction and continental growth in the Late Paleozoic. However, it is still controversial on the exact time of ocean-continent transition so far. This study investigates rhyolites with columnar joint in the West Junggar for the first time.Based on zircon U-Pb dating, we determined that the ages of the newly-discovered rhyolites are between 303.6 and 294.5 Ma, belonging to Late Carboniferous–Early Permian, which is the oldest rhyolite with columnar joint preserved in the world at present. Geochemical results show that the characteristics of the major element compositions include a high content of SiO_2(75.78–79.20 wt%) and a moderate content of Al_2O_3(12.21–13.19 wt%). The total alkali content(K_2O +Na_2O) is 6.14–8.05 wt%, among which K_2O is 2.09–4.72 wt% and the rate of K_2O/Na_2O is 0.38–3.05. Over-based minerals such as Ne, Lc, and Ac do not appear. The contents of TiO_2(0.09–0.24 wt%), CaO(0.15–0.99 wt%) and MgO(0.06–0.18 wt%) are low. A/CNK=0.91–1.68, A/NK=1.06–1.76, and as such, these are associated with the quasi-aluminum-weak peraluminous high potassium calc-alkaline and some calc-alkaline magma series. These rhyolites show a significant negative Eu anomaly with relative enrichment of LREE and LILE(Rb, Ba, Th, U, K) and depletion of Sr, HREE and HFSE(Nb, Ta, Ti, P). These rhyolites also have the characteristics of an A2-type granite, similar to the Miaoergou batholith,which indicates they both were affected by post-orogenic extension. Combining petrological, zircon U-Pb dating and geochemical characteristics of the rhyolites, we conclude that the specific time of ocean-continent transition of the West Junggar is the Late Carboniferous–Early Permian.展开更多
Based on analyses of the share of documents of structural geology and tectonics in the GeoRef system over 100 years in the last century, and the historical change of international （31 years） and domestic （16 years...Based on analyses of the share of documents of structural geology and tectonics in the GeoRef system over 100 years in the last century, and the historical change of international （31 years） and domestic （16 years） document counts of various topics in structural geology and tectonics, the position of structural geology and tectonics in the geosciences is evaluated and the major advaces in fields of plate tectonics, continental dynamics and global dynamics are reviewed. Our attention mainly focuses on the advances in studies of structural analysis, deformation mechanisms and rheology of rocks, contractional tectonics and late- and post-orogenic extensional collapse in orogens, large-scale strikeslip faults and indentation-extrusion tectonics, active tectonics and natural hazards. The relationships of structural geology and tectonics with petrology and geochronology are also discussed in terms of intersection of scientific disciplines. Finally, some suggestions are proposed for the further development of structural geology and tectonics in China.展开更多
As one of the early COVID-19 epidemic outbreak areas,China attracted the global news media’s attention at the beginning of 2020.During the epidemic period,Chinese people united and actively fought against the epidemi...As one of the early COVID-19 epidemic outbreak areas,China attracted the global news media’s attention at the beginning of 2020.During the epidemic period,Chinese people united and actively fought against the epidemic.However,in the eyes of the international public,the situation reported about China is not optimistic.To better understand how the international public portrays China,especially during the epidemic,we present a case study with big data technology.We aim to answer three questions:(1)What has the international media focused on during the COVID-19 epidemic period?(2)What is the media’s tone when they report China?(3)What is the media’s attitude when talking about China?In detail,we crawled more than 280000 pieces of news from 57 mainstream media agencies in 22 countries and made some interesting observations.For example,international media paid more attention to Chinese livelihood during the COVID-19 epidemic period.In March and April,“progress of Chinese vaccines,”“specific drugs and treatments,”and“virus outbreak in U.S.”became the media’s most common topics.In terms of news attitude,Cuba,Malaysia,and Venezuela had a positive attitude toward China,while France,Canada,and the United Kingdom had a negative attitude.Our study can help understand China’s image in the eyes of the international media and provide a sound basis for image analysis.展开更多
Docker,as a mainstream container solution,adopts the Copy-on-Write(CoW)mechanism in its storage drivers.This mechanism satisfies the need of different containers to share the same image.However,when a single container...Docker,as a mainstream container solution,adopts the Copy-on-Write(CoW)mechanism in its storage drivers.This mechanism satisfies the need of different containers to share the same image.However,when a single container performs operations such as modification of an image file,a duplicate is created in the upper readwrite layer,which contributes to the runtime overhead.When the accessed image file is fairly large,this additional overhead becomes non-negligible.Here we present the concept of Dynamic Prefetching Strategy Optimization(DPSO),which optimizes the Co W mechanism for a Docker container on the basis of the dynamic prefetching strategy.At the beginning of the container life cycle,DPSO pre-copies up the image files that are most likely to be copied up later to eliminate the overhead caused by performing this operation during application runtime.The experimental results show that DPSO has an average prefetch accuracy of greater than 78%in complex scenarios and could effectively eliminate the overhead caused by the CoW mechanism.展开更多
Virtualization technology provides an opportu- nity to acieve efficient usage of computing resources. How- ever, the management of services on virtualization infras- tructure is still in the preliminary stage. Contstr...Virtualization technology provides an opportu- nity to acieve efficient usage of computing resources. How- ever, the management of services on virtualization infras- tructure is still in the preliminary stage. Contstructing user service environments quickly and efficiently remains a chal- lenge. This paper presents a service oriented multiple-VM deployment system （SO-MVDS） for creating and configur- ing virtual appliances running services on-demand. The sys- tem provides a template management model where all the virtual machines are created based on the templates with the software environment pre-prepared. To improve the deploy- ment performance, we explore some strategies for incremen- tal mechanisms and deployment. We also design a service de- ployment mechanism to dynamically and automatically de- ploy multiple services within virtual appliances. We evalu- ate both the deployment time and I/O performance using the proposed incremental mechanism. The experimental results show that the incremental mechanism outperforms the clone one.展开更多
基金supported by the National Key Research and Development Program of China(the DREAM—Deep Resource Exploration and Advanced MiningGrant No.2018YFC0603701)the China Geological Survey(Grant nos.DD20160083 and DD20190011)。
文摘This is a review of the formation and tectonic evolution of the continental Asia in Phanerozoic.The continental Asia has formed on the bases of some pre-Cambrian cratons,such as the Siberia,India,Arabia,North China,Tarim,South China,and Indochina,through multi-stage plate convergence and collisional collages in Phanerozoic.The north-central Asia had experienced the expansion and subduction of the Paleo-Asian Ocean(PAO)in the early Paleozoic and the closure of the PAO in the late Paleozoic and early Mesozoic,forming the PAO regime and Central Asian orogenic belt(CAOB).In the core of the CAOB,the Mongol-Okhotsk Ocean(MOO)opened with limited expansion in the Early Permian and finally closed in the Late Jurassic–Early Cretaceous.The south-central Asia had experienced mainly multi-stage oceanic opening,subduction and collision evolution in the Tethys Ocean,forming the Tethys regime and Himalaya-Tibetan orogenic belt.In eastern Asia,the plate subduction and continental margin orogeny on western margin of the Pacific Ocean,forms the West Pacific regime and West Pacific orogenic belt.The PAO,Tethys,and West Pacific regimes,together with Precambrian cratons among or surrounding them,made up the major tectonic and dynamic systems of the continental Asia in Phanerozoic.Major tectonic events,such as the Early Paleozoic Qilian,Uralian,and Dunhuang orogeneses,the late Paleozoic East Junggar,Tianshan and West Junggar orogeneses,the Middle to Late Permian Ailaoshan orogeny and NorthSouth Lhasa collision,the early Mesozoic Indochina-South China and North-South China collisions,the late Mesozoic Mongolia-Okhotsk orogeny,Lhasa-Qiangtang collision,and intra-continental Yanshanian orogeny,and the Cenozoic IndoAsian,Arab-Asian,and West Pacific margin collisions,constrained the formation and evolution of the continental Asia.The complex dynamic systems have left large number of deformation features,such as large-scale strike-slip faults,thrustfold systems and extensional detachments on the continental Asia.Based on past tectonics,a f
基金supported by the China Geological Survey (grant numbers DD20160083 and DD20160344-05)the National Key Research and Development Program of China (grant numbers 2018YFC0603701)Fundamental Research Funds for Central Public Welfare Research Institutes (grant numbers CAGS-YWF201706)
文摘The West Junggar of the western Central Asian Orogenic Belt is one of the typical regions in the term of ocean subduction, contraction and continental growth in the Late Paleozoic. However, it is still controversial on the exact time of ocean-continent transition so far. This study investigates rhyolites with columnar joint in the West Junggar for the first time.Based on zircon U-Pb dating, we determined that the ages of the newly-discovered rhyolites are between 303.6 and 294.5 Ma, belonging to Late Carboniferous–Early Permian, which is the oldest rhyolite with columnar joint preserved in the world at present. Geochemical results show that the characteristics of the major element compositions include a high content of SiO_2(75.78–79.20 wt%) and a moderate content of Al_2O_3(12.21–13.19 wt%). The total alkali content(K_2O +Na_2O) is 6.14–8.05 wt%, among which K_2O is 2.09–4.72 wt% and the rate of K_2O/Na_2O is 0.38–3.05. Over-based minerals such as Ne, Lc, and Ac do not appear. The contents of TiO_2(0.09–0.24 wt%), CaO(0.15–0.99 wt%) and MgO(0.06–0.18 wt%) are low. A/CNK=0.91–1.68, A/NK=1.06–1.76, and as such, these are associated with the quasi-aluminum-weak peraluminous high potassium calc-alkaline and some calc-alkaline magma series. These rhyolites show a significant negative Eu anomaly with relative enrichment of LREE and LILE(Rb, Ba, Th, U, K) and depletion of Sr, HREE and HFSE(Nb, Ta, Ti, P). These rhyolites also have the characteristics of an A2-type granite, similar to the Miaoergou batholith,which indicates they both were affected by post-orogenic extension. Combining petrological, zircon U-Pb dating and geochemical characteristics of the rhyolites, we conclude that the specific time of ocean-continent transition of the West Junggar is the Late Carboniferous–Early Permian.
文摘Based on analyses of the share of documents of structural geology and tectonics in the GeoRef system over 100 years in the last century, and the historical change of international （31 years） and domestic （16 years） document counts of various topics in structural geology and tectonics, the position of structural geology and tectonics in the geosciences is evaluated and the major advaces in fields of plate tectonics, continental dynamics and global dynamics are reviewed. Our attention mainly focuses on the advances in studies of structural analysis, deformation mechanisms and rheology of rocks, contractional tectonics and late- and post-orogenic extensional collapse in orogens, large-scale strikeslip faults and indentation-extrusion tectonics, active tectonics and natural hazards. The relationships of structural geology and tectonics with petrology and geochronology are also discussed in terms of intersection of scientific disciplines. Finally, some suggestions are proposed for the further development of structural geology and tectonics in China.
文摘As one of the early COVID-19 epidemic outbreak areas,China attracted the global news media’s attention at the beginning of 2020.During the epidemic period,Chinese people united and actively fought against the epidemic.However,in the eyes of the international public,the situation reported about China is not optimistic.To better understand how the international public portrays China,especially during the epidemic,we present a case study with big data technology.We aim to answer three questions:(1)What has the international media focused on during the COVID-19 epidemic period?(2)What is the media’s tone when they report China?(3)What is the media’s attitude when talking about China?In detail,we crawled more than 280000 pieces of news from 57 mainstream media agencies in 22 countries and made some interesting observations.For example,international media paid more attention to Chinese livelihood during the COVID-19 epidemic period.In March and April,“progress of Chinese vaccines,”“specific drugs and treatments,”and“virus outbreak in U.S.”became the media’s most common topics.In terms of news attitude,Cuba,Malaysia,and Venezuela had a positive attitude toward China,while France,Canada,and the United Kingdom had a negative attitude.Our study can help understand China’s image in the eyes of the international media and provide a sound basis for image analysis.
基金supported by the National Key Research and Development Program of China(No.2018YFB1003203)the National Natural Science Foundation of China(Nos.61772218 and 61433019)+1 种基金the Outstanding Youth Foundation of Hubei Province(No.2016CFA032)the Chinese Universities Scientific Fund(No.2019kfyRCPY030)。
文摘Docker,as a mainstream container solution,adopts the Copy-on-Write(CoW)mechanism in its storage drivers.This mechanism satisfies the need of different containers to share the same image.However,when a single container performs operations such as modification of an image file,a duplicate is created in the upper readwrite layer,which contributes to the runtime overhead.When the accessed image file is fairly large,this additional overhead becomes non-negligible.Here we present the concept of Dynamic Prefetching Strategy Optimization(DPSO),which optimizes the Co W mechanism for a Docker container on the basis of the dynamic prefetching strategy.At the beginning of the container life cycle,DPSO pre-copies up the image files that are most likely to be copied up later to eliminate the overhead caused by performing this operation during application runtime.The experimental results show that DPSO has an average prefetch accuracy of greater than 78%in complex scenarios and could effectively eliminate the overhead caused by the CoW mechanism.
文摘Virtualization technology provides an opportu- nity to acieve efficient usage of computing resources. How- ever, the management of services on virtualization infras- tructure is still in the preliminary stage. Contstructing user service environments quickly and efficiently remains a chal- lenge. This paper presents a service oriented multiple-VM deployment system （SO-MVDS） for creating and configur- ing virtual appliances running services on-demand. The sys- tem provides a template management model where all the virtual machines are created based on the templates with the software environment pre-prepared. To improve the deploy- ment performance, we explore some strategies for incremen- tal mechanisms and deployment. We also design a service de- ployment mechanism to dynamically and automatically de- ploy multiple services within virtual appliances. We evalu- ate both the deployment time and I/O performance using the proposed incremental mechanism. The experimental results show that the incremental mechanism outperforms the clone one.
