Driven by the global“dual-carbon”goals,hydrogen fuel cell electric vehicles(FCEVs)are being rapidly promoted as a zero-emission transportation solution.However,their large-scale application is constrained by issues ...Driven by the global“dual-carbon”goals,hydrogen fuel cell electric vehicles(FCEVs)are being rapidly promoted as a zero-emission transportation solution.However,their large-scale application is constrained by issues such as inefficient operation,poor information flow between vehicles and stations,and potential safety hazards,which are caused by insufficient intelligence of hydrogen refueling stations.This study aims to address these problems by deeply integrating Cellular Vehicle-to-Everything(C-V2X)technology with hydrogen refueling stations,thereby building a safe,efficient,and low-carbon hydrogen energy application ecosystem to promote the global transition to zero-carbon transportation.Firstly,through literature review and technical analysis,this study expounds on the core technologies and process flows of current hydrogen refueling stations,aswell as the technical architecture and development evolution of C-V2X technology.Then,based on the analysis of relevant literature,it proposes a“vehicle-road-station-cloud”collaborative architecture that integrates C-V2X with hydrogen refueling stations.Combined with 5G communication and big data technologies,it elaborates on the implementation path for achieving real-time data interaction among hydrogen refueling stations,hydrogen-powered vehicles,and road infrastructure.This interconnection mode enables hydrogen refueling stations to obtain real-time information of surrounding vehicles,which plays an important role in building a safe,efficient,and low-carbon hydrogen energy application ecosystem and promoting the global transition to zero-carbon transportation.Finally,the future development prospects and potential of this scheme are put forward.展开更多
Injection-production coupling(IPC) technology holds substantial potential for boosting oil recovery and enhancing economic efficiency.Despite this potential,discussion on gas injection coupling,especially in relation ...Injection-production coupling(IPC) technology holds substantial potential for boosting oil recovery and enhancing economic efficiency.Despite this potential,discussion on gas injection coupling,especially in relation to microscopic mechanisms,remains relatively sparse.This study utilizes microscopic visualization experiments to investigate the mechanisms of residual oil mobilization under various IPC scenarios,complemented by mechanical analysis at different stages.The research quantitatively assesses the degree of microscopic oil recovery and the distribution of residual oil across different injection-production methods.Findings reveal that during the initial phase of continuous gas injection(CGI),the process closely mimics miscible displacement,gradually transitioning to immiscible displacement as CO_(2)extraction progresses.Compared to CGI,the asynchronous injection-production(AIP) method improved the microscopic oil recovery rate by 6.58%.This enhancement is mainly attributed to significant variations in the pressure field in the AIP method,which facilitate the mobilization of columnar and porous re sidual oil.Furthermo re,the synchronous cycle injection(SCI) method increased microscopic oil recovery by 13.77% and 7.19% compared to CGI and AIP,respectively.In the SCI method,membrane oil displays filame ntary and Karman vo rtex street flow patterns.The dissolved and expanded crude oil te nds to accumulate and grow at the oil-solid interface due to adhesive forces,thereby reducing migration resistance.The study findings provide a theoretical foundation for improving oil recovery in lowpermeability reservoirs.展开更多
Two-dimensional(2D) barcode technology is an electronic tagging technology based on combination of computer and optical technology. It is an important way of information collection and input. 2D barcode technology has...Two-dimensional(2D) barcode technology is an electronic tagging technology based on combination of computer and optical technology. It is an important way of information collection and input. 2D barcode technology has been widely used in various fields of logistics,production automation,and e-commerce,but it also has brought about a series of safety problems. Based on evolutionary encryption technology,this paper improved algorithm of traditional 2D barcode generation,to improve forgery- proof performance of 2D barcode. This algorithm is applied to agricultural products quality and safety traceability system and the results show that it is effective.展开更多
BACKGROUND Diabetes distress is an important factor in treatment outcomes and results in poor behavioral and biological consequences.Technology has been used in management programs of diabetes to improve communication...BACKGROUND Diabetes distress is an important factor in treatment outcomes and results in poor behavioral and biological consequences.Technology has been used in management programs of diabetes to improve communication between patients and health care providers and to promote education about the disease and its psychological aspects,which can impact the self-efficacy of the programs.However,the true impact of technological approaches on the management of type 2 diabetes distress remains controversial.AIM To investigate the effectiveness of technology interventions on the management of type 2 diabetes distress.METHODS Studies published from 2014 to 2019 were searched in five databases:MEDLINE,PubMed,Library and Information Science Source,Academic Search Ultimate and PsycINFO.The Boolean logic search terms were:(1)T2Diabetes;(2)diabetes distress;and(3)technology OR mobile OR phone OR application OR web.We also systematically searched the reference lists of the included studies and relevant reviews.Randomized controlled trials with technology interventions,type 2 diabetes patients and diabetes distress as the outcome were selected.The Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement was followed.RESULTS Of the 88 studies selected,nine full articles met the inclusion criteria and were subjected to final careful review.On the JADAD scale,one article was classified as having poor quality and eight as having good quality.Six out of nine articles showed that technology interventions had a positive impact on diabetes distress scale scores when compared with the initial data.Among the six articles,five showed a greater reduction in the diabetes distress scores from control interventions.Web-based interventions had good results when users received personalized feedback and routine caregiver support and attention.CONCLUSION Technology interventions can contribute positively to the management of type 2 diabetes distress,especially with a tailored approach in conjunction with caregiver interaction with patients.展开更多
The emission control of non-CO2greenhouse gases is conducive to slowing down global warming.It is also helpful in controlling environmental pollution,and beneficial in improving the local health benefits.This paper ai...The emission control of non-CO2greenhouse gases is conducive to slowing down global warming.It is also helpful in controlling environmental pollution,and beneficial in improving the local health benefits.This paper aims at six kinds of non-CO2greenhouse gases under United Nations Framework Convention on Climate Change,namely methane(CH4),nitrous oxide(N2O),hydrofluorocarbons(HFCs),perfluorocarbons(PFCs),sulfur hexafluoride(SF6),and nitrogen trifluoride(NF3).This paper analyzes the emission status and trend of China’s non-CO2greenhouse gases,and provides some technology selections for non-CO2emission reduction.Through strategic policy arrangements and appropriate technology choices,China can gain environmental protection and greenhouse gas control.展开更多
The Long March 2 F(LM-2F) launch vehicle, the only launch vehicle designed for manned space flight in China, successfully launched the Tiangong 2 space laboratory and the Shenzhou 11 manned spaceship into orbits in 20...The Long March 2 F(LM-2F) launch vehicle, the only launch vehicle designed for manned space flight in China, successfully launched the Tiangong 2 space laboratory and the Shenzhou 11 manned spaceship into orbits in 2016 respectively. In this study, it introduces the technological improvements for enhancing the reliability of the LM-2F launch vehicle in the aspects of general technology, control system, manufacture and ground support system. The LM-2F launch vehicle will continue to provide more contributions to the Chinese Space Station Project with its high reliability and 100% success rate.展开更多
We investigate the design of satellite network slicing for the first time to provide customized services for the diversified applications,and propose a novel scheme for satellite end-to-end(E2E) network slicing based ...We investigate the design of satellite network slicing for the first time to provide customized services for the diversified applications,and propose a novel scheme for satellite end-to-end(E2E) network slicing based on 5G technology,which provides a view of common satellite network slicing and supports flexible network deployment between the satellite and the ground.Specifically,considering the limited satellite network resource and the characteristics of the satellite channel,we propose a novel satellite E2E network slicing architecture.Therein,the deployment of the network functions between the satellite and the ground is coordinately considered.Subsequently,the classification and the isolation technologies of satellite network sub-slices are proposed adaptively based on 5G technology to support resource allocation on demand.Then,we develop the management technologies for the satellite E2E network slicing including slicing key performance indicator(KPI) design,slicing deployment,and slicing management.Finally,the analysis of the challenges and future work shows the potential research in the future.展开更多
Objective:To surveill emerging variants by nanopore technology-based genome sequencing in different COVID-19 waves in Sri Lanka and to examine the association with the sample characteristics,and vaccination status.Met...Objective:To surveill emerging variants by nanopore technology-based genome sequencing in different COVID-19 waves in Sri Lanka and to examine the association with the sample characteristics,and vaccination status.Methods:The study analyzed 207 RNA positive swab samples received to sequence laboratory during different waves.The N gene cut-off threshold of less than 30 was considered as the major inclusion criteria.Viral RNA was extracted,and elutes were subjected to nanopore sequencing.All the sequencing data were uploaded in the publicly accessible database,GISAID.Results:The Omicron,Delta and Alpha variants accounted for 58%,22%and 4%of the variants throughout the period.Less than 1%were Kappa variant and 16%of the study samples remained unassigned.Omicron variant was circulated among all age groups and in all the provinces.Ct value and variants assigned percentage was 100%in Ct values of 10-15 while only 45%assigned Ct value over 25.Conclusions:The present study examined the emergence,prevalence,and distribution of SARS-CoV-2 variants locally and has shown that nanopore technology-based genome sequencing enables whole genome sequencing in a low resource setting country.展开更多
TiB2P/Al composite was successfully fabricated by squeeze casting technology.Its mechanical and tribological properties were evaluated .The elimination of Ti-Al intermetallic compound was confirmed by X-ray diffracti...TiB2P/Al composite was successfully fabricated by squeeze casting technology.Its mechanical and tribological properties were evaluated .The elimination of Ti-Al intermetallic compound was confirmed by X-ray diffraction （XRD）studies.At 45% volume fraction ,the bending strength at ambient temperature was 934 MPa.And the fracture modes included ductile failure of Al matrix and brittle fracture of TiB2 pqrticles.In dry sliding wear mode ,severe plastic deformation and adhesive wear were found on te worn surfaces of the SiCP/Al composite .But no obvious characteristics of adhesion or abrasion wear were observed on that of the TiB2P/Al composites .At the stedady stage ,the friction coefficient of the SiCP/Al composite was about 0.6 .While that of TiB2P/Al composite was only only about 0.16-0.17.展开更多
Five experimental self-shielded flux cored wires are fabricated withdifferent amount of Fe_2O_3 in the flux. The effect of Fe_2O_3 on welding technology and mechanicalproperties of weld metals deposited by these wires...Five experimental self-shielded flux cored wires are fabricated withdifferent amount of Fe_2O_3 in the flux. The effect of Fe_2O_3 on welding technology and mechanicalproperties of weld metals deposited by these wires are studied. The results show that with theincrease of Fe_2O_3 in the mix, the melting point of the pretreated mix is increased. LiBaF_3 andBaFe_(12)O_(19), which are very low in inherent moisture, are formed after the pretreatment. Themechanical properties are evaluated to the weld metals. The low temperature notch toughness of theweld metals is increased linearly with the Fe_2O_3 content in the flux due to the balance betweenFe_2O_3 and residual Al in the weld metal. The optimum Fe_2O_3 content in flux is 2.5 percent approx3.5 percent.展开更多
In this study,an integrated technology is proposed for the absorption and utilization of CO_(2)in alkanolamine solution for the preparation of BaCO_(3)in a high-gravity environment.The effects of absorbent type,high-g...In this study,an integrated technology is proposed for the absorption and utilization of CO_(2)in alkanolamine solution for the preparation of BaCO_(3)in a high-gravity environment.The effects of absorbent type,high-gravity factor,gas/liquid ratio,and initial BaCl2concentration on the absorption rate and amount of CO_(2)and the preparation of BaCO_(3)are investigated.The results reveal that the absorption rate and amount of CO_(2)follow the order of ethyl alkanolamine(MEA)>diethanol amine(DEA)>N-methyldiethanolamine(MDEA),and thus MEA is the most effective absorbent for CO_(2)absorption.The absorption rate and amount of CO_(2)under high gravity are higher than that under normal gravity.Notably,the absorption rate at 75 min under high gravity is approximately 2 times that under normal gravity.This is because the centrifugal force resulting from the high-speed rotation of the packing can greatly increase gas-liquid mass transfer and micromixing.The particle size of BaCO_(3)prepared in the rotating packed bed is in the range of 57.2—89 nm,which is much smaller than that prepared in the bubbling reactor(>100.3 nm),and it also has higher purity(99.6%)and larger specific surface area(14.119 m^(2)·g^(-1)).It is concluded that the high-gravity technology has the potential to increase the absorption and utilization of CO_(2)in alkanolamine solution for the preparation of BaCO_(3).This study provides new insights into carbon emissions reduction and carbon utilization.展开更多
This paper systematically reviews the current applications of various spatial information technologies in CO_(2)sequestration monitoring,analyzes the challenges faced by spatial information technologies in CO_(2)seque...This paper systematically reviews the current applications of various spatial information technologies in CO_(2)sequestration monitoring,analyzes the challenges faced by spatial information technologies in CO_(2)sequestration monitoring,and prospects the development of spatial information technologies in CO_(2)sequestration monitoring.Currently,the spatial information technologies applied in CO_(2)sequestration monitoring mainly include five categories:eddy covariance method,remote sensing technology,geographic information system,Internet of Things technology,and global navigation satellite system.These technologies are involved in three aspects:monitoring data acquisition,positioning and data transmission,and data management and decision support.Challenges faced by the spatial information technologies in CO_(2)sequestration monitoring include:selecting spatial information technologies that match different monitoring purposes,different platforms,and different monitoring sites;establishing effective data storage and computing capabilities to cope with the broad sources and large volumes of monitoring data;and promoting collaborative operations by interacting and validating spatial information technologies with mature monitoring technologies.In the future,it is necessary to establish methods and standards for designing spatial information technology monitoring schemes,develop collaborative application methods for cross-scale monitoring technologies,integrate spatial information technologies with artificial intelligence and high-performance computing technologies,and accelerate the application of spatial information technologies in carbon sequestration projects in China.展开更多
V-2 technology was transferred from Germany to the Union of Soviet Socialist Republics(USSR)and then on to China.The USSR imitated the captured German V-2 rocket,and independently developed the R-2.Later,China imitate...V-2 technology was transferred from Germany to the Union of Soviet Socialist Republics(USSR)and then on to China.The USSR imitated the captured German V-2 rocket,and independently developed the R-2.Later,China imitated the R-2 rocket provided by the USSR,and independently developed the Dong Feng-2(DF-2).The imitation or localization of foreign products is a key stage prior to independent development.Independent development of new models,in turn,is not only indicative of an upgrading of the transferred technology and the mastering of foreign technology,but also an illustration of innovation.Talent is the crucial resource on which technology transfer relies.The administrative system and domestic collaboration network required to coordinate the necessary tasks,including research,experimentation,design,and manufacture were established both in the USSR and in China.展开更多
Back-propagation neural network was applied to predict and optimize the synthetic technology of 2-chloro-4,6-dinitroresorcinol. A model was established based on back-propagation neural network using the experimental d...Back-propagation neural network was applied to predict and optimize the synthetic technology of 2-chloro-4,6-dinitroresorcinol. A model was established based on back-propagation neural network using the experimental data of homogeneous design as the training sample set and the technological parameters were optimized by it. The optimal technological parameters are as follows： the reaction time is 4h, the reaction temperature is 80℃, the molar ratio of NaOH to 4,6-dinitro-1,2,3-trichlorobenzene is 5.5：1, the molar ratio of methanol to 4,6-dinitro-1,2,3- trichlorobenzene is 11：1, and the molar ratio of water to 4,6-dinitro-1,2,3-trichlorobenzene is 70：1. Under the optimal conditions, three groups of experiments were performed and the average yield of 2-chloro-4,6-dinitroresorcinol is 96.64%, the absolute error of it with the predicted value is -1.07%.展开更多
Signals from infrared detector are very weak in SO2 concentration measuring system.In order to improve the sensitivity of detection,combining with filter correlation technology and infrared absorption principle,the we...Signals from infrared detector are very weak in SO2 concentration measuring system.In order to improve the sensitivity of detection,combining with filter correlation technology and infrared absorption principle,the weak signal processing circuit is designed according to correlation detection technology.Under laboratory conditions,system performance of SO2 concentration is tested,and the experimental data are analyzed and processed.Then relationship of SO2 concentration and the measuring voltage is provided to prove that the design improves measuring sensitivity of the system.展开更多
AbstFeS has an excellent performance in removing heavy metal chromium(Ⅵ)in wastewater due to its good adsorption and reduction.The properties of easy aggregation and oxidization of nano-FeS,however,limit the applicat...AbstFeS has an excellent performance in removing heavy metal chromium(Ⅵ)in wastewater due to its good adsorption and reduction.The properties of easy aggregation and oxidization of nano-FeS,however,limit the applications of FeS in engineering.In this study,one FeS adsorbent supported by Al_(2)O_(3) was prepared using high-gravity technology in IS-RPB(Impinging Stream Rotating Packed Bed)to overcome polymerization and oxidation of nano-FeS.Experimental results showed that FeS was uniformly loaded on the surface and pores of Al_(2)O_(3).The specific surface area of FeS/Al_(2)O_(3) is 125 m2·g^(-1) which is nearly 1.6 times that of pure FeS.The adsorption capacity of FeS/Al_(2)O_(3) for chromium(Ⅵ)is 200 mg·g^(-1),1.4 times that of pure FeS.pH value and ionic strength are strongly correlated with the chromium removal performance of FeS/Al_(2)O_(3).Over 98%of chromium can be removed when pH values of FeS/Al_(2)O_(3) ranged from 4 to 6.Higher adsorption capacity is achieved with higher ionic strength in FeS/Al_(2)O_(3).The FeS/Al_(2)O_(3) maintained more than 95%of the adsorption capacity after being preserved for one month,but only 70%for pure FeS.The removal processes of chromium(Ⅵ)conformes to a pseudo-second-order kinetic model(R2≥0.9986),indicating that the rate-limiting step is a chemical sorption process instead of a mass transfer.展开更多
At 23:18 Beijing time on January 5,a LM-3B carrier rocket lifted off from the Xichang Satellite Launch Center,sending a communication technology test satellite into its preset orbit.This successful launch was a good s...At 23:18 Beijing time on January 5,a LM-3B carrier rocket lifted off from the Xichang Satellite Launch Center,sending a communication technology test satellite into its preset orbit.This successful launch was a good start for China’s launch missions in 2017.The Communications Technology Test Satellite 2 was developed by the Shanghai Academy of Spaceflight Technology.It is a next-generation telecom-展开更多
基金supported in part by the Key Research and Development Program of Shandong Province under Grant 2022KJHZ002.
文摘Driven by the global“dual-carbon”goals,hydrogen fuel cell electric vehicles(FCEVs)are being rapidly promoted as a zero-emission transportation solution.However,their large-scale application is constrained by issues such as inefficient operation,poor information flow between vehicles and stations,and potential safety hazards,which are caused by insufficient intelligence of hydrogen refueling stations.This study aims to address these problems by deeply integrating Cellular Vehicle-to-Everything(C-V2X)technology with hydrogen refueling stations,thereby building a safe,efficient,and low-carbon hydrogen energy application ecosystem to promote the global transition to zero-carbon transportation.Firstly,through literature review and technical analysis,this study expounds on the core technologies and process flows of current hydrogen refueling stations,aswell as the technical architecture and development evolution of C-V2X technology.Then,based on the analysis of relevant literature,it proposes a“vehicle-road-station-cloud”collaborative architecture that integrates C-V2X with hydrogen refueling stations.Combined with 5G communication and big data technologies,it elaborates on the implementation path for achieving real-time data interaction among hydrogen refueling stations,hydrogen-powered vehicles,and road infrastructure.This interconnection mode enables hydrogen refueling stations to obtain real-time information of surrounding vehicles,which plays an important role in building a safe,efficient,and low-carbon hydrogen energy application ecosystem and promoting the global transition to zero-carbon transportation.Finally,the future development prospects and potential of this scheme are put forward.
基金supported by the National Natural Science Foundation of China (Nos.52374064,51974347,52474072)the Shandong Provincial Universities Youth Innovation and Technology Support Program (2022KJ065)。
文摘Injection-production coupling(IPC) technology holds substantial potential for boosting oil recovery and enhancing economic efficiency.Despite this potential,discussion on gas injection coupling,especially in relation to microscopic mechanisms,remains relatively sparse.This study utilizes microscopic visualization experiments to investigate the mechanisms of residual oil mobilization under various IPC scenarios,complemented by mechanical analysis at different stages.The research quantitatively assesses the degree of microscopic oil recovery and the distribution of residual oil across different injection-production methods.Findings reveal that during the initial phase of continuous gas injection(CGI),the process closely mimics miscible displacement,gradually transitioning to immiscible displacement as CO_(2)extraction progresses.Compared to CGI,the asynchronous injection-production(AIP) method improved the microscopic oil recovery rate by 6.58%.This enhancement is mainly attributed to significant variations in the pressure field in the AIP method,which facilitate the mobilization of columnar and porous re sidual oil.Furthermo re,the synchronous cycle injection(SCI) method increased microscopic oil recovery by 13.77% and 7.19% compared to CGI and AIP,respectively.In the SCI method,membrane oil displays filame ntary and Karman vo rtex street flow patterns.The dissolved and expanded crude oil te nds to accumulate and grow at the oil-solid interface due to adhesive forces,thereby reducing migration resistance.The study findings provide a theoretical foundation for improving oil recovery in lowpermeability reservoirs.
基金Supported by National Key Technology Research and Development Program of the Ministry of Science and Technology of China(2012BAD35B04)
文摘Two-dimensional(2D) barcode technology is an electronic tagging technology based on combination of computer and optical technology. It is an important way of information collection and input. 2D barcode technology has been widely used in various fields of logistics,production automation,and e-commerce,but it also has brought about a series of safety problems. Based on evolutionary encryption technology,this paper improved algorithm of traditional 2D barcode generation,to improve forgery- proof performance of 2D barcode. This algorithm is applied to agricultural products quality and safety traceability system and the results show that it is effective.
文摘BACKGROUND Diabetes distress is an important factor in treatment outcomes and results in poor behavioral and biological consequences.Technology has been used in management programs of diabetes to improve communication between patients and health care providers and to promote education about the disease and its psychological aspects,which can impact the self-efficacy of the programs.However,the true impact of technological approaches on the management of type 2 diabetes distress remains controversial.AIM To investigate the effectiveness of technology interventions on the management of type 2 diabetes distress.METHODS Studies published from 2014 to 2019 were searched in five databases:MEDLINE,PubMed,Library and Information Science Source,Academic Search Ultimate and PsycINFO.The Boolean logic search terms were:(1)T2Diabetes;(2)diabetes distress;and(3)technology OR mobile OR phone OR application OR web.We also systematically searched the reference lists of the included studies and relevant reviews.Randomized controlled trials with technology interventions,type 2 diabetes patients and diabetes distress as the outcome were selected.The Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement was followed.RESULTS Of the 88 studies selected,nine full articles met the inclusion criteria and were subjected to final careful review.On the JADAD scale,one article was classified as having poor quality and eight as having good quality.Six out of nine articles showed that technology interventions had a positive impact on diabetes distress scale scores when compared with the initial data.Among the six articles,five showed a greater reduction in the diabetes distress scores from control interventions.Web-based interventions had good results when users received personalized feedback and routine caregiver support and attention.CONCLUSION Technology interventions can contribute positively to the management of type 2 diabetes distress,especially with a tailored approach in conjunction with caregiver interaction with patients.
基金supported by the Policy Study on China’s Low-carbon Industrial Development(No.201312)
文摘The emission control of non-CO2greenhouse gases is conducive to slowing down global warming.It is also helpful in controlling environmental pollution,and beneficial in improving the local health benefits.This paper aims at six kinds of non-CO2greenhouse gases under United Nations Framework Convention on Climate Change,namely methane(CH4),nitrous oxide(N2O),hydrofluorocarbons(HFCs),perfluorocarbons(PFCs),sulfur hexafluoride(SF6),and nitrogen trifluoride(NF3).This paper analyzes the emission status and trend of China’s non-CO2greenhouse gases,and provides some technology selections for non-CO2emission reduction.Through strategic policy arrangements and appropriate technology choices,China can gain environmental protection and greenhouse gas control.
文摘The Long March 2 F(LM-2F) launch vehicle, the only launch vehicle designed for manned space flight in China, successfully launched the Tiangong 2 space laboratory and the Shenzhou 11 manned spaceship into orbits in 2016 respectively. In this study, it introduces the technological improvements for enhancing the reliability of the LM-2F launch vehicle in the aspects of general technology, control system, manufacture and ground support system. The LM-2F launch vehicle will continue to provide more contributions to the Chinese Space Station Project with its high reliability and 100% success rate.
文摘We investigate the design of satellite network slicing for the first time to provide customized services for the diversified applications,and propose a novel scheme for satellite end-to-end(E2E) network slicing based on 5G technology,which provides a view of common satellite network slicing and supports flexible network deployment between the satellite and the ground.Specifically,considering the limited satellite network resource and the characteristics of the satellite channel,we propose a novel satellite E2E network slicing architecture.Therein,the deployment of the network functions between the satellite and the ground is coordinately considered.Subsequently,the classification and the isolation technologies of satellite network sub-slices are proposed adaptively based on 5G technology to support resource allocation on demand.Then,we develop the management technologies for the satellite E2E network slicing including slicing key performance indicator(KPI) design,slicing deployment,and slicing management.Finally,the analysis of the challenges and future work shows the potential research in the future.
文摘Objective:To surveill emerging variants by nanopore technology-based genome sequencing in different COVID-19 waves in Sri Lanka and to examine the association with the sample characteristics,and vaccination status.Methods:The study analyzed 207 RNA positive swab samples received to sequence laboratory during different waves.The N gene cut-off threshold of less than 30 was considered as the major inclusion criteria.Viral RNA was extracted,and elutes were subjected to nanopore sequencing.All the sequencing data were uploaded in the publicly accessible database,GISAID.Results:The Omicron,Delta and Alpha variants accounted for 58%,22%and 4%of the variants throughout the period.Less than 1%were Kappa variant and 16%of the study samples remained unassigned.Omicron variant was circulated among all age groups and in all the provinces.Ct value and variants assigned percentage was 100%in Ct values of 10-15 while only 45%assigned Ct value over 25.Conclusions:The present study examined the emergence,prevalence,and distribution of SARS-CoV-2 variants locally and has shown that nanopore technology-based genome sequencing enables whole genome sequencing in a low resource setting country.
文摘TiB2P/Al composite was successfully fabricated by squeeze casting technology.Its mechanical and tribological properties were evaluated .The elimination of Ti-Al intermetallic compound was confirmed by X-ray diffraction （XRD）studies.At 45% volume fraction ,the bending strength at ambient temperature was 934 MPa.And the fracture modes included ductile failure of Al matrix and brittle fracture of TiB2 pqrticles.In dry sliding wear mode ,severe plastic deformation and adhesive wear were found on te worn surfaces of the SiCP/Al composite .But no obvious characteristics of adhesion or abrasion wear were observed on that of the TiB2P/Al composites .At the stedady stage ,the friction coefficient of the SiCP/Al composite was about 0.6 .While that of TiB2P/Al composite was only only about 0.16-0.17.
文摘Five experimental self-shielded flux cored wires are fabricated withdifferent amount of Fe_2O_3 in the flux. The effect of Fe_2O_3 on welding technology and mechanicalproperties of weld metals deposited by these wires are studied. The results show that with theincrease of Fe_2O_3 in the mix, the melting point of the pretreated mix is increased. LiBaF_3 andBaFe_(12)O_(19), which are very low in inherent moisture, are formed after the pretreatment. Themechanical properties are evaluated to the weld metals. The low temperature notch toughness of theweld metals is increased linearly with the Fe_2O_3 content in the flux due to the balance betweenFe_2O_3 and residual Al in the weld metal. The optimum Fe_2O_3 content in flux is 2.5 percent approx3.5 percent.
基金supported by Research Project Supported by Horizon Europe Framework Programme(101183092)Shanxi Scholarship Council of China(2023-128)+2 种基金National Natural Science Foundation of China(22208328)Fundamental Research Program of Shanxi Province(20210302124618)Small and mediumsized oriented scientific and technological enterprises innovation ability improvement project of Shandong Province(2023TSGC0004)。
文摘In this study,an integrated technology is proposed for the absorption and utilization of CO_(2)in alkanolamine solution for the preparation of BaCO_(3)in a high-gravity environment.The effects of absorbent type,high-gravity factor,gas/liquid ratio,and initial BaCl2concentration on the absorption rate and amount of CO_(2)and the preparation of BaCO_(3)are investigated.The results reveal that the absorption rate and amount of CO_(2)follow the order of ethyl alkanolamine(MEA)>diethanol amine(DEA)>N-methyldiethanolamine(MDEA),and thus MEA is the most effective absorbent for CO_(2)absorption.The absorption rate and amount of CO_(2)under high gravity are higher than that under normal gravity.Notably,the absorption rate at 75 min under high gravity is approximately 2 times that under normal gravity.This is because the centrifugal force resulting from the high-speed rotation of the packing can greatly increase gas-liquid mass transfer and micromixing.The particle size of BaCO_(3)prepared in the rotating packed bed is in the range of 57.2—89 nm,which is much smaller than that prepared in the bubbling reactor(>100.3 nm),and it also has higher purity(99.6%)and larger specific surface area(14.119 m^(2)·g^(-1)).It is concluded that the high-gravity technology has the potential to increase the absorption and utilization of CO_(2)in alkanolamine solution for the preparation of BaCO_(3).This study provides new insights into carbon emissions reduction and carbon utilization.
基金Supported by the CNPC Science and Technology Major Project(2021ZZ01-05).
文摘This paper systematically reviews the current applications of various spatial information technologies in CO_(2)sequestration monitoring,analyzes the challenges faced by spatial information technologies in CO_(2)sequestration monitoring,and prospects the development of spatial information technologies in CO_(2)sequestration monitoring.Currently,the spatial information technologies applied in CO_(2)sequestration monitoring mainly include five categories:eddy covariance method,remote sensing technology,geographic information system,Internet of Things technology,and global navigation satellite system.These technologies are involved in three aspects:monitoring data acquisition,positioning and data transmission,and data management and decision support.Challenges faced by the spatial information technologies in CO_(2)sequestration monitoring include:selecting spatial information technologies that match different monitoring purposes,different platforms,and different monitoring sites;establishing effective data storage and computing capabilities to cope with the broad sources and large volumes of monitoring data;and promoting collaborative operations by interacting and validating spatial information technologies with mature monitoring technologies.In the future,it is necessary to establish methods and standards for designing spatial information technology monitoring schemes,develop collaborative application methods for cross-scale monitoring technologies,integrate spatial information technologies with artificial intelligence and high-performance computing technologies,and accelerate the application of spatial information technologies in carbon sequestration projects in China.
基金supported in part by the Youth Innovation Promotion Association CAS(2019157)。
文摘V-2 technology was transferred from Germany to the Union of Soviet Socialist Republics(USSR)and then on to China.The USSR imitated the captured German V-2 rocket,and independently developed the R-2.Later,China imitated the R-2 rocket provided by the USSR,and independently developed the Dong Feng-2(DF-2).The imitation or localization of foreign products is a key stage prior to independent development.Independent development of new models,in turn,is not only indicative of an upgrading of the transferred technology and the mastering of foreign technology,but also an illustration of innovation.Talent is the crucial resource on which technology transfer relies.The administrative system and domestic collaboration network required to coordinate the necessary tasks,including research,experimentation,design,and manufacture were established both in the USSR and in China.
文摘Back-propagation neural network was applied to predict and optimize the synthetic technology of 2-chloro-4,6-dinitroresorcinol. A model was established based on back-propagation neural network using the experimental data of homogeneous design as the training sample set and the technological parameters were optimized by it. The optimal technological parameters are as follows： the reaction time is 4h, the reaction temperature is 80℃, the molar ratio of NaOH to 4,6-dinitro-1,2,3-trichlorobenzene is 5.5：1, the molar ratio of methanol to 4,6-dinitro-1,2,3- trichlorobenzene is 11：1, and the molar ratio of water to 4,6-dinitro-1,2,3-trichlorobenzene is 70：1. Under the optimal conditions, three groups of experiments were performed and the average yield of 2-chloro-4,6-dinitroresorcinol is 96.64%, the absolute error of it with the predicted value is -1.07%.
文摘Signals from infrared detector are very weak in SO2 concentration measuring system.In order to improve the sensitivity of detection,combining with filter correlation technology and infrared absorption principle,the weak signal processing circuit is designed according to correlation detection technology.Under laboratory conditions,system performance of SO2 concentration is tested,and the experimental data are analyzed and processed.Then relationship of SO2 concentration and the measuring voltage is provided to prove that the design improves measuring sensitivity of the system.
基金The present research was under the financial support of Shanxi Provincial Natural Fund(201901D111136).
文摘AbstFeS has an excellent performance in removing heavy metal chromium(Ⅵ)in wastewater due to its good adsorption and reduction.The properties of easy aggregation and oxidization of nano-FeS,however,limit the applications of FeS in engineering.In this study,one FeS adsorbent supported by Al_(2)O_(3) was prepared using high-gravity technology in IS-RPB(Impinging Stream Rotating Packed Bed)to overcome polymerization and oxidation of nano-FeS.Experimental results showed that FeS was uniformly loaded on the surface and pores of Al_(2)O_(3).The specific surface area of FeS/Al_(2)O_(3) is 125 m2·g^(-1) which is nearly 1.6 times that of pure FeS.The adsorption capacity of FeS/Al_(2)O_(3) for chromium(Ⅵ)is 200 mg·g^(-1),1.4 times that of pure FeS.pH value and ionic strength are strongly correlated with the chromium removal performance of FeS/Al_(2)O_(3).Over 98%of chromium can be removed when pH values of FeS/Al_(2)O_(3) ranged from 4 to 6.Higher adsorption capacity is achieved with higher ionic strength in FeS/Al_(2)O_(3).The FeS/Al_(2)O_(3) maintained more than 95%of the adsorption capacity after being preserved for one month,but only 70%for pure FeS.The removal processes of chromium(Ⅵ)conformes to a pseudo-second-order kinetic model(R2≥0.9986),indicating that the rate-limiting step is a chemical sorption process instead of a mass transfer.
文摘At 23:18 Beijing time on January 5,a LM-3B carrier rocket lifted off from the Xichang Satellite Launch Center,sending a communication technology test satellite into its preset orbit.This successful launch was a good start for China’s launch missions in 2017.The Communications Technology Test Satellite 2 was developed by the Shanghai Academy of Spaceflight Technology.It is a next-generation telecom-
