Lithium-sulfur(Li-S) batteries can provide far higher energy density than currently commercialized lithium ion batteries, but challenges remain before it they are used in practice.One of the challenges is the shuttle ...Lithium-sulfur(Li-S) batteries can provide far higher energy density than currently commercialized lithium ion batteries, but challenges remain before it they are used in practice.One of the challenges is the shuttle effect that originates from soluble intermediates, like lithium polysulfides. To address this issue, we report a novel laminar composite, N,O-carboxymethyl chitosan-reduced graphene oxide(CC-rGO), which is manufactured via the self-assembly of CC onto GO and subsequent reduction of GO under an extreme condition of 1 Pa and-50°C. The synthesized laminar CC-rGO composite is mixed with acetylene black(AB) and coated on a commercial polypropylene(PP) membrane, resulting in a separator(CC-rGO/AB/PP) that can not only completely suppress the polysulfides penetration, but also can accelerate the lithium ion transportation, providing a Li-S battery with excellent cyclic stability and rate capability. As confirmed by theoretic simulations, this unique feature of CC-rGO is attributed to its strong repulsive interaction to polysulfide anions and its benefit for fast lithium ion transportation through the paths paved by the heteroatoms in CC.展开更多
Due to the characteristics of reservoir formation,the producing level of low permeability reservoir is relatively very low.It is hard to obtain high recovery through conventional development schemes.Considering the ti...Due to the characteristics of reservoir formation,the producing level of low permeability reservoir is relatively very low.It is hard to obtain high recovery through conventional development schemes.Considering the tight matrix,complex fracture system,low production level of producers,and low recovery factor ofMblock in Xinjiang oilfield,it is selected for on-site pilot test of nitrogen foam flooding.Detailed flooding scheme is made and the test results are evaluated respectively both for producers and injectors.The pressure index,filling degree,and fluid injection profile are found to be all improved in injectors after injection of nitrogen foam.The oil production,water cut and liquid production file are also improved in most of the producers,with the natural decline rate in the test area become slow.Results show that nitrogen foam flooding technology can be good technical storage for enhanced oil recovery in low permeability reservoir.展开更多
This study was conducted to explore the construction of scaffolding teaching mode of Traditional Chinese Medicine under the background of"Internet+".The students of Grade 2018 majoring in traditional Chinese...This study was conducted to explore the construction of scaffolding teaching mode of Traditional Chinese Medicine under the background of"Internet+".The students of Grade 2018 majoring in traditional Chinese medicine were selected as the object,and some chapters of the textbook of traditional Chinese medicine were selected and taught by the traditional teaching mode while interspersing the scaffolding teaching mode,in order to help the implementation of the scaffolding teaching model.We adopted the methods of setting up situational scaffolding,question scaffolding and guide scaffolding to carry out relevant teaching contents.The scaffolding instruction model has a good degree of participation,and to a certain extent,it stimulates students'self-consciousness and enthusiasm,and improves their ability of analyzing and solving problems and their spirit of innovation.展开更多
The purpose of this study was to discuss shape,scale and superimposed types of sandy gravel bodies in sandy-gravel braided distributary channel.Lithofacies analysis,hierarchy bounding surface analysis and subsurface d...The purpose of this study was to discuss shape,scale and superimposed types of sandy gravel bodies in sandy-gravel braided distributary channel.Lithofacies analysis,hierarchy bounding surface analysis and subsurface dense well pattern combining with outcrops method were used to examine reservoir architecture patterns of sandy gravel braided distributary channel based on cores,well logging,and outcrops data,and the reservoir architecture patterns of sandy gravel braided distributary channels in different grades have been established.The study shows:(1)The main reservoir architecture elements for sandy gravel braided channel delta are distributary channel and overbank sand,while reservoir flow barrier elements are interchannel and lacustrine mudstone.(2)The compound sand bodies in the sandy gravel braided delta distributary channel take on three shapes:sheet-like distributary channel sand body,interweave strip distributary channel sand body,single strip distributary channel sand body.(3)Identification marks of single distributary channel include:elevation of sand body top,lateral overlaying,“thick-thin-thick”feature of sand bodies,interchannel mudstone and overbank sand between distributary channels and the differences in well log curve shape of sand bodies.(4)Nine lithofacies types were distinguished in distributary channel unit interior,different channel units have different lithofacies association sequence.展开更多
Periodic frequent pattern discovery is a non-trivial task to discover frequent patterns based on user interests using a periodicity measure.Although conventional algorithms for periodic frequent pattern detection have...Periodic frequent pattern discovery is a non-trivial task to discover frequent patterns based on user interests using a periodicity measure.Although conventional algorithms for periodic frequent pattern detection have numerous applications,there is still little research on periodic frequent pattern detection of individual passengers in the metro.The travel behavior of individual passengers has complex spatio-temporal characteristics in the metro network,which may pose new challenges in discovering periodic frequent patterns of individual metro passengers and developing mining algorithms based on real-world smart card data.This study addresses these issues by proposing a novel pattern for metro passenger travel pattern called periodic frequent passenger traffic patterns with time granularities and station attributes(PFPTS).This discovered pattern can automatically capture the features of the temporal dimension(morning and evening peak hours,week)and the spatial dimension(entering and leaving stations).The corresponding complete mining algorithm with the PFPTS-tree structure has been developed.To evaluate the performance of PFPTS-tree,several experiments are conducted on one-year real-world smart card data collected by an automatic fare collection system in a certain large metro network.The results show that PFPTS-Tree is efficient and can discover numerous interesting periodic frequent patterns of metro passengers in the real-world dataset.展开更多
Periodic pattern mining is of great significance for understanding passenger travel behav-ior,but the previous works mainly focused on the trajectory data and the dimension of the spot/point.Besides,many uncertain fac...Periodic pattern mining is of great significance for understanding passenger travel behav-ior,but the previous works mainly focused on the trajectory data and the dimension of the spot/point.Besides,many uncertain factors(severe weather,traffic accident,etc.)may interfere with discovering original and accurate periodic travel patterns.This paper pro-poses a novel type of travel pattern called motif periodic frequent pattern(MPFP),which captures the periodicity of network temporal motifs of individual metro passengers with higher-order spatio-temporal characteristics considering,uncertain disturbances.We also propose a new complete mining algorithm MPFP-growth to extract MPFP from smart card data(SCD),and apply the real long-time-span experimental data from a large-scale metro system is applied.Results show that frequent-travel metro passengers usually have some typical MPFPs with the temporal periodic characteristic of“week”.Only the top 10 types of all 4624 types account for about 95%of all motifs and the top 5 types constitute about 90%,and the MPFP of the top 3 types of motifs account for nearly 80%of all periodic patterns,in which Mono-MPFP and 2-MPFP are the main ones.The relatively stable time range of MPFP is three months,and the threshold for the optimal uncertain disturbance factor should be set at 5%.Additionally,several interesting typical MPFPs of individual metro commuting passengers and their proportions are introduced to further understand the multifarious variants of MPFP.展开更多
Servitization of manufacturing has become one of the main pathways for transition and upgrade in the manufacturing industry.New information and communication technologies(ICTs),such as the Internet of Things,Big Data,...Servitization of manufacturing has become one of the main pathways for transition and upgrade in the manufacturing industry.New information and communication technologies(ICTs),such as the Internet of Things,Big Data,and Cloud Computing have enabled the servitization of manufacturing in terms of value creation,resource management,and supply chain management.This study presents a comprehensive review on the servitization in operations management in the era of new ICTs.A new value chain framework is proposed under the business model that revolves around servitization,which showcases the new activities and ways of implementation in the era of new ICTs.The virtualization,configuration,and evaluation of integrated manufacturing and service resources are analyzed.In particular,the methods used in new ICT-supported resource management platforms are surveyed.Problems in the supply chain management in manufacturing services(including the selection of partners,as well as the coordination,planning,and scheduling among members)are presented.This study concludes with a discussion on state-of-the-art servitization in operations management in the era of new ICTs.展开更多
The Mobei reservoir is a low-permeability-sandstone reservoir,due to differences in pore geometry,it can be divided into two independent reservoirs:A1 reservoir and A2 reservoir.For better understanding the water floo...The Mobei reservoir is a low-permeability-sandstone reservoir,due to differences in pore geometry,it can be divided into two independent reservoirs:A1 reservoir and A2 reservoir.For better understanding the water flooding development effects of Mobei reservoir,the mercury intrusion porosimetry,water flooding CT scanning and micro-CT scanning experiments are used in this study.The result shows that the reservoir has the strong heterogeneity which is weaken gradually from A1 reservoir to A2 reservoir.Reservoir pore radius is mainly distributed in the 100e200 microns,the throat radius is mainly distributed in the 1e3 micron.The water flooding core experiment in each reservoir shows a short water-free oil production period and rapid water cut after breakthrough.The A2 reservoir core flooding process is similar to piston displacement,the A1 reservoir core flooding process refers to the phenomenon(The fingering phenomenon in the process of core flooding in the A1 reservoir is obvious).The calculated water drive efficiency of the A2 reservoir is 61.2%,which is higher than 49.1%of the A1 reservoir.According to the CT scanning process,the Mobei oilfield has low micro displacement efficiency and the A1 reservoir has a smaller spread(sweep area)and higher residual oil saturation.展开更多
基金supported by the National Key Research and Development Project (Grant No. 2018YFE0124800)the National Key Research Program of China (Grant No.2022YFA1503100)+7 种基金Science and Technology Project of Jiangsu Province (Grant No. BZ2020011)National Natural Science Foundation of China (Grants No. 22173067)the Science and Technology Development FundMacao SAR(FDCT No. 0052/2021/A)Collaborative Innovation Center of Suzhou Nano Science&Technologythe Priority Academic Program Development of Jiangsu Higher Education Institutions (PAPD)the 111 ProjectJoint International Research Laboratory of Carbon-Based Functional Materials and Devices
文摘Lithium-sulfur(Li-S) batteries can provide far higher energy density than currently commercialized lithium ion batteries, but challenges remain before it they are used in practice.One of the challenges is the shuttle effect that originates from soluble intermediates, like lithium polysulfides. To address this issue, we report a novel laminar composite, N,O-carboxymethyl chitosan-reduced graphene oxide(CC-rGO), which is manufactured via the self-assembly of CC onto GO and subsequent reduction of GO under an extreme condition of 1 Pa and-50°C. The synthesized laminar CC-rGO composite is mixed with acetylene black(AB) and coated on a commercial polypropylene(PP) membrane, resulting in a separator(CC-rGO/AB/PP) that can not only completely suppress the polysulfides penetration, but also can accelerate the lithium ion transportation, providing a Li-S battery with excellent cyclic stability and rate capability. As confirmed by theoretic simulations, this unique feature of CC-rGO is attributed to its strong repulsive interaction to polysulfide anions and its benefit for fast lithium ion transportation through the paths paved by the heteroatoms in CC.
基金supported by the Prospective and Fundamental Project of CNPC“Study on the EOR Technology by Foam Flooding(2021DJ1603)”by Open Fund of State Key Laboratory of Enhanced Oil Recovery,CNPC(2022-KFKT-29).
文摘Due to the characteristics of reservoir formation,the producing level of low permeability reservoir is relatively very low.It is hard to obtain high recovery through conventional development schemes.Considering the tight matrix,complex fracture system,low production level of producers,and low recovery factor ofMblock in Xinjiang oilfield,it is selected for on-site pilot test of nitrogen foam flooding.Detailed flooding scheme is made and the test results are evaluated respectively both for producers and injectors.The pressure index,filling degree,and fluid injection profile are found to be all improved in injectors after injection of nitrogen foam.The oil production,water cut and liquid production file are also improved in most of the producers,with the natural decline rate in the test area become slow.Results show that nitrogen foam flooding technology can be good technical storage for enhanced oil recovery in low permeability reservoir.
基金Supported by 2017 Teaching Quality and Teaching Reform Project of Guizhou University of Traditional Chinese Medicine(3045-045170035)2018 School-level Undergraduate Teaching Engineering Construction Project of Guiyang College of Traditional Chinese Medicine(GZY-JG(2018)03)。
文摘This study was conducted to explore the construction of scaffolding teaching mode of Traditional Chinese Medicine under the background of"Internet+".The students of Grade 2018 majoring in traditional Chinese medicine were selected as the object,and some chapters of the textbook of traditional Chinese medicine were selected and taught by the traditional teaching mode while interspersing the scaffolding teaching mode,in order to help the implementation of the scaffolding teaching model.We adopted the methods of setting up situational scaffolding,question scaffolding and guide scaffolding to carry out relevant teaching contents.The scaffolding instruction model has a good degree of participation,and to a certain extent,it stimulates students'self-consciousness and enthusiasm,and improves their ability of analyzing and solving problems and their spirit of innovation.
基金This project is supported by the National Science Foundation for Distinguished Young Scholars of China(Grant No.41502216)Supported by the Yangtze youth fund(2015cqn55).
文摘The purpose of this study was to discuss shape,scale and superimposed types of sandy gravel bodies in sandy-gravel braided distributary channel.Lithofacies analysis,hierarchy bounding surface analysis and subsurface dense well pattern combining with outcrops method were used to examine reservoir architecture patterns of sandy gravel braided distributary channel based on cores,well logging,and outcrops data,and the reservoir architecture patterns of sandy gravel braided distributary channels in different grades have been established.The study shows:(1)The main reservoir architecture elements for sandy gravel braided channel delta are distributary channel and overbank sand,while reservoir flow barrier elements are interchannel and lacustrine mudstone.(2)The compound sand bodies in the sandy gravel braided delta distributary channel take on three shapes:sheet-like distributary channel sand body,interweave strip distributary channel sand body,single strip distributary channel sand body.(3)Identification marks of single distributary channel include:elevation of sand body top,lateral overlaying,“thick-thin-thick”feature of sand bodies,interchannel mudstone and overbank sand between distributary channels and the differences in well log curve shape of sand bodies.(4)Nine lithofacies types were distinguished in distributary channel unit interior,different channel units have different lithofacies association sequence.
基金supported by the National Natural Science Foundation of China(Grant No.52102382)the Shanghai Science and Technology Committee(Grant No.20DZ1203201)+1 种基金the Fundamental Research Funds for the Central Universities(2022-5-YB-04)the Shanghai Shentong Metro Group Co.,Ltd.(Grant Nos.JSKY21R005-1-WT-21064 and JS-KY21R005-2).
文摘Periodic frequent pattern discovery is a non-trivial task to discover frequent patterns based on user interests using a periodicity measure.Although conventional algorithms for periodic frequent pattern detection have numerous applications,there is still little research on periodic frequent pattern detection of individual passengers in the metro.The travel behavior of individual passengers has complex spatio-temporal characteristics in the metro network,which may pose new challenges in discovering periodic frequent patterns of individual metro passengers and developing mining algorithms based on real-world smart card data.This study addresses these issues by proposing a novel pattern for metro passenger travel pattern called periodic frequent passenger traffic patterns with time granularities and station attributes(PFPTS).This discovered pattern can automatically capture the features of the temporal dimension(morning and evening peak hours,week)and the spatial dimension(entering and leaving stations).The corresponding complete mining algorithm with the PFPTS-tree structure has been developed.To evaluate the performance of PFPTS-tree,several experiments are conducted on one-year real-world smart card data collected by an automatic fare collection system in a certain large metro network.The results show that PFPTS-Tree is efficient and can discover numerous interesting periodic frequent patterns of metro passengers in the real-world dataset.
基金supported by the National Natural Science Foundation of China(No.52372332)the Fundamental Research Funds for the Central Universities of China(No.2022-5-YB-04)the Shanghai Shentong Metro Group Co.,Ltd.(Nos.JSKY21R005-1-WT-21064,and JS-KY22R033-2).
文摘Periodic pattern mining is of great significance for understanding passenger travel behav-ior,but the previous works mainly focused on the trajectory data and the dimension of the spot/point.Besides,many uncertain factors(severe weather,traffic accident,etc.)may interfere with discovering original and accurate periodic travel patterns.This paper pro-poses a novel type of travel pattern called motif periodic frequent pattern(MPFP),which captures the periodicity of network temporal motifs of individual metro passengers with higher-order spatio-temporal characteristics considering,uncertain disturbances.We also propose a new complete mining algorithm MPFP-growth to extract MPFP from smart card data(SCD),and apply the real long-time-span experimental data from a large-scale metro system is applied.Results show that frequent-travel metro passengers usually have some typical MPFPs with the temporal periodic characteristic of“week”.Only the top 10 types of all 4624 types account for about 95%of all motifs and the top 5 types constitute about 90%,and the MPFP of the top 3 types of motifs account for nearly 80%of all periodic patterns,in which Mono-MPFP and 2-MPFP are the main ones.The relatively stable time range of MPFP is three months,and the threshold for the optimal uncertain disturbance factor should be set at 5%.Additionally,several interesting typical MPFPs of individual metro commuting passengers and their proportions are introduced to further understand the multifarious variants of MPFP.
基金This work is supported by the research grant from the National Natural Science Foundation of China(Grant Nos.71602081,71871142,and 71672078)the Belt and Road Special Project of Lanzhou University(Grant No.20181dbryb015)and the Fundamental Research Funds for the Central Universities(Grant No.2020jbkyzy036).
文摘Servitization of manufacturing has become one of the main pathways for transition and upgrade in the manufacturing industry.New information and communication technologies(ICTs),such as the Internet of Things,Big Data,and Cloud Computing have enabled the servitization of manufacturing in terms of value creation,resource management,and supply chain management.This study presents a comprehensive review on the servitization in operations management in the era of new ICTs.A new value chain framework is proposed under the business model that revolves around servitization,which showcases the new activities and ways of implementation in the era of new ICTs.The virtualization,configuration,and evaluation of integrated manufacturing and service resources are analyzed.In particular,the methods used in new ICT-supported resource management platforms are surveyed.Problems in the supply chain management in manufacturing services(including the selection of partners,as well as the coordination,planning,and scheduling among members)are presented.This study concludes with a discussion on state-of-the-art servitization in operations management in the era of new ICTs.
基金We gratefully acknowledge financial support from This work was supported by the National Science and Technology Major Project of China(2017ZX05070002,2017ZX05013003-001).
文摘The Mobei reservoir is a low-permeability-sandstone reservoir,due to differences in pore geometry,it can be divided into two independent reservoirs:A1 reservoir and A2 reservoir.For better understanding the water flooding development effects of Mobei reservoir,the mercury intrusion porosimetry,water flooding CT scanning and micro-CT scanning experiments are used in this study.The result shows that the reservoir has the strong heterogeneity which is weaken gradually from A1 reservoir to A2 reservoir.Reservoir pore radius is mainly distributed in the 100e200 microns,the throat radius is mainly distributed in the 1e3 micron.The water flooding core experiment in each reservoir shows a short water-free oil production period and rapid water cut after breakthrough.The A2 reservoir core flooding process is similar to piston displacement,the A1 reservoir core flooding process refers to the phenomenon(The fingering phenomenon in the process of core flooding in the A1 reservoir is obvious).The calculated water drive efficiency of the A2 reservoir is 61.2%,which is higher than 49.1%of the A1 reservoir.According to the CT scanning process,the Mobei oilfield has low micro displacement efficiency and the A1 reservoir has a smaller spread(sweep area)and higher residual oil saturation.
