Experimental investigations on dynamic in-plane compressive behavior of a plain weave composite were performed using the split Hopkinson pressure bar. A quantitative criterion for calculating the constant strain rate ...Experimental investigations on dynamic in-plane compressive behavior of a plain weave composite were performed using the split Hopkinson pressure bar. A quantitative criterion for calculating the constant strain rate of composites was established. Then the upper limit of strain rate, restricted by stress equilibrium and constant loading rate, was rationally estimated and confirmed by tests. Within the achievable range of 0.001/s-895/s, it was found that the strength increased first and subsequently decreased as the strain rate increased. This feature was also reflected by the turning point(579/s) of the bilinear model for strength prediction. The transition in failure mechanism, from local opening damage to completely splitting destruction, was mainly responsible for such strain rate effects. And three major failure modes were summarized under microscopic observations: fiber fracture, inter-fiber fracture, and interface delamination. Finally, by introducing a nonlinear damage variable, a simplified ZWT model was developed to characterize the dynamic mechanical response. Excellent agreement was shown between the experimental and simulated results.展开更多
In this study,high-gravity intensified heterogeneous catalytic ozonation is utilized for treatment of phenol-containing wastewater,and the kinetics of the direct reaction between ozone and phenol in the presence of ex...In this study,high-gravity intensified heterogeneous catalytic ozonation is utilized for treatment of phenol-containing wastewater,and the kinetics of the direct reaction between ozone and phenol in the presence of excess tertiary butanol(TBA)is investigated.It is revealed that the direct reaction between ozone and phenol in the rotating packed bed(RPB)follows the pseudo-first-order kinetics with a reaction rate constant higher than that in the conventional bubbling reactor(BR).Under different conditions of temperature,initial pH,high-gravity factor,and gaseous ozone concentration,the apparent reaction rate constant varies in the range of 0.0160–0.115 min-1.An empirical power-exponential model is established to characterize the effects of these parameters on the direct reaction between ozone and phenol by high-gravity intensified heterogeneous catalytic ozonation.展开更多
Background Disrupted white matter(WM)microstructure has been commonly identified in youth at clinical high risk(CHR)for psychosis.Several lines of evidence suggest that fatty acids,especially unsaturated fatty acids(U...Background Disrupted white matter(WM)microstructure has been commonly identified in youth at clinical high risk(CHR)for psychosis.Several lines of evidence suggest that fatty acids,especially unsaturated fatty acids(UFAs),might play a crucial role in the WM pathology of early onset psychosis.However,evidence linking UFA and WM microstructure in CHR is quite sparse.Aims We investigated the relationship between the plasma UFA level and WM microstructure in CHR participants and healthy controls(HC).Methods Plasma fatty acids were assessed and diffusion tensor imaging(DTI)data were performed with tract-based spatial statistics(TBSS)analysis for 66 individuals at CHR for psychosis and 70 HC.Results Both the global and regional diffusion measures showed significant between-group differences,with decreased fractional anisotropy(FA)but increased mean diffusivity(MD)and radial diffusivity(RD)found in the CHR group compared with the HC group.On top of that,we found that in the HC group,plasma arachidic acid showed obvious trend-level associations with higher global FA,lower global MD and lower global RD,which regionally spread over the corpus callosum,right anterior and superior corona radiata,bilateral anterior and posterior limb of the internal capsule,and bilateral superior longitudinal fasciculus.However,there were no associations between global WM measures and any UFA in the CHR group.Conversely,we even found negative associations between arachidic acid levels and regional FA values in the right superior longitudinal fasciculus and right retrolenticular part of the internal capsule in the CHR group.Conclusions Compared with the HC group,CHR subjects exhibited a different pattern of association between WM microstructure and plasma UFA,with a neuroprotective effect found in the HC group but not in the CHR group.Such discrepancy could be due to the excessively upregulated UFAs accumulated in the plasma of the CHR group,highlighting the role of balanced plasma-membrane fatty acids homeostasis in WM development.展开更多
Relation extraction between entity pairs is an increasingly critical area in natural language processing.Recently the pre-trained bidirectional encoder representation from transformer(BERT)performs excellendy on the t...Relation extraction between entity pairs is an increasingly critical area in natural language processing.Recently the pre-trained bidirectional encoder representation from transformer(BERT)performs excellendy on the text classification or sequence labelling tasks.Here,the high-level syntactic features that consider the dependency between each word and the target entities into the pre-trained language models are incorporated.Our model also utilizes the intermediate layers of BERT to acquire different levels of semantic information and designs multi-granularity features for final relation classification.Our model offers a momentous improvement over the published methods for the relation extraction on the widely used data sets.展开更多
The influence of N on the precipitation behavior,associated corrosion,and mechanical properties of S32654 were investigated by microstructural,electrochemical,and mechanical analyses.Increasing the N content results i...The influence of N on the precipitation behavior,associated corrosion,and mechanical properties of S32654 were investigated by microstructural,electrochemical,and mechanical analyses.Increasing the N content results in several alterations:(1) grain refinement,which promotes intergranular precipitation;(2) a linear increase in the driving force for Cr2 N and Mo activity,which accelerates the precipitation of intergranular Cr2 N and π phase,respectively;(3) a linear decrease in the driving force for σ phase and Cr activity,which suppresses the formation of intragranular σ phase.The total amount of precipitates first decreased and then increased with the N content increasing.Furthermore,the intergranular corrosion susceptibility depended substantially on the total amount of precipitates and also first exhibited a decreasing and then an increasing trend as the N content increased.In addition,aging precipitation caused a considerable decrement in the ultimate tensile strength(UTS) and a remarkable increment in the yield strength(YS).Both the UTS and YS always increased with N content increasing throughout the solution and aging process.Whereas the elongation was considerably sensitive to the aging treatment,it exhibited marginal variation with the N content increasing.展开更多
The application of iron–carbon(Fe–C)micro-electrolysis to wastewater treatment is limited by the passivation potential of the Fe–C packing.In order to address this problem,high-gravity intensified Fe–C micro-elect...The application of iron–carbon(Fe–C)micro-electrolysis to wastewater treatment is limited by the passivation potential of the Fe–C packing.In order to address this problem,high-gravity intensified Fe–C micro-electrolysis was proposed in this study for degradation of dinitrotoluene wastewater in a rotating packed bed(RPB)using commercial Fe–C particles as the packing.The effects of reaction time,high-gravity factor,liquid flow rate and initial solution pH were investigated.The degradation intermediates were determined by gas chromatography-mass spectrometry,and the possible degradation pathways of nitro compounds by Fe–C micro-electrolysis in RPB were also proposed.It is found that under optimal conditions,the removal rate of nitro compounds reaches 68.4%at 100 min.The removal rate is maintained at approximately 68%after 4 cycles in RPB,but it is decreased substantially from 57.9%to 36.8%in a stirred tank reactor.This is because RPB can increase the specific surface area and the renewal of the liquid–solid interface,and as a result the degradation efficiency of Fe–C micro-electrolysis is improved and the active sites on the Fe–C surface can be regenerated for continuous use.In conclusion,high-gravity intensified Fe–C micro-electrolysis can weaken the passivation of Fe–C particles and extend their service life.展开更多
Aeromonas sobria,a Gram-negative bacterium that can colonize both humans and animals,is found in a variety of environments,including water,seafood,meat,and vegetables(Cahill,1990;Galindo et al.,2004;Song et al,2019).A...Aeromonas sobria,a Gram-negative bacterium that can colonize both humans and animals,is found in a variety of environments,including water,seafood,meat,and vegetables(Cahill,1990;Galindo et al.,2004;Song et al,2019).Aeromonas spp.are conditionally pathogenic bacteria in aquaculture,which can rapidly proliferate,causing disease and even death in fish,especially when the environment is degraded(Neamat-Allah et al,2020,2021a,2021b).In developing countries,Aeromonas spp.have been associated with a wide spectrum of infections in humans,including gastroen-teritis,wound infections,septicemia,and lung infections(San Joaquin and Pickett,1988;Wang et al,2009;Su et al,2013).Infections caused by Aeromonas spp.are usually more severe in immunocompromised individuals(Miyamoto et al,2017).展开更多
Internet-scale open source software (OSS) pro- duction in various communities generates abundant reusable resources for software developers. However, finding the de- sired and mature software with keyword queries fr...Internet-scale open source software (OSS) pro- duction in various communities generates abundant reusable resources for software developers. However, finding the de- sired and mature software with keyword queries from a considerable number of candidates, especially for the fresher, is a significant challenge because current search services often fail to understand the semantics of user queries. In this paper, we construct a software term database (STDB) by analyzing tagging data in Stack Overflow and propose a correlationbased software search (CBSS) approach that performs correlation retrieval based on the term relevance obtained from STDB. In addition, we design a novel ranking method to optimize the initial retrieval result. We explore four research questions in four experiments, respectively, to evaluate the effectiveness of the STDB and investigate the performance of the CBSS. The experiment results show that the proposed CBSS can effectively respond to keyword-based software searches and significantly outperforms other existing search services at finding mature software.展开更多
Introduction:With the large-scale roll-out of the coronavirus disease 2019(COVID-19)booster vaccination effort(a vaccine dose given 6 months after completing primary vaccination)in China,we explore when and how China ...Introduction:With the large-scale roll-out of the coronavirus disease 2019(COVID-19)booster vaccination effort(a vaccine dose given 6 months after completing primary vaccination)in China,we explore when and how China could lift non-pharmacological interventions(NPIs)against COVID-19 in 2022.Methods:Using a modified susceptible-infectiousrecovered(SIR)mathematical model,we projected the COVID-19 epidemic situation and required medical resources in Guangdong Province,China.Results:If the number of people entering from overseas recovers to 20%of the number in 2019,the epidemic in 2022 could be controlled at a low level by a containment(215 local cases)or suppression strategy(1,397 local cases).A mitigation strategy would lead to 21,722 local cases.A coexistence strategy would lead to a large epidemic with 6,850,083 local cases that would overwhelm Guangdong’s medical system.With 50%or 100%recovery of the 2019 level of travelers from overseas,the epidemic could also be controlled with containment or suppression,but enormous resources,including more hotel rooms for border quarantine,will be required.However,coexistence would lead to an uncontrollable epidemic with 12,922,032 local cases.Discussion:With booster vaccinations,the number of travelers from overseas could increase slightly in 2022,but a suppression strategy would need to be maintained to ensure a controllable epidemic.展开更多
基金the National Science and Technology Major Project(Grant No.2017-VII-0011-0106)Natural Science Foundation of Heilongjiang Province(Grant No.ZD2019A001).
文摘Experimental investigations on dynamic in-plane compressive behavior of a plain weave composite were performed using the split Hopkinson pressure bar. A quantitative criterion for calculating the constant strain rate of composites was established. Then the upper limit of strain rate, restricted by stress equilibrium and constant loading rate, was rationally estimated and confirmed by tests. Within the achievable range of 0.001/s-895/s, it was found that the strength increased first and subsequently decreased as the strain rate increased. This feature was also reflected by the turning point(579/s) of the bilinear model for strength prediction. The transition in failure mechanism, from local opening damage to completely splitting destruction, was mainly responsible for such strain rate effects. And three major failure modes were summarized under microscopic observations: fiber fracture, inter-fiber fracture, and interface delamination. Finally, by introducing a nonlinear damage variable, a simplified ZWT model was developed to characterize the dynamic mechanical response. Excellent agreement was shown between the experimental and simulated results.
基金supported by the Fund for Shanxi Province Higher Education“1331 Project”for Improving Quality and Efficiency Construction(nuc2021-006)Key Research&Development Plan of Shanxi Province(201903D321059)+1 种基金Scientific Activities of Selected Returned Overseas Professionals in Shanxi Province(20200004)Transformation and Cultivation Projects of Scientific and Technological Achievements in Universities of Shanxi Province Institutions(2020CG040).
文摘In this study,high-gravity intensified heterogeneous catalytic ozonation is utilized for treatment of phenol-containing wastewater,and the kinetics of the direct reaction between ozone and phenol in the presence of excess tertiary butanol(TBA)is investigated.It is revealed that the direct reaction between ozone and phenol in the rotating packed bed(RPB)follows the pseudo-first-order kinetics with a reaction rate constant higher than that in the conventional bubbling reactor(BR).Under different conditions of temperature,initial pH,high-gravity factor,and gaseous ozone concentration,the apparent reaction rate constant varies in the range of 0.0160–0.115 min-1.An empirical power-exponential model is established to characterize the effects of these parameters on the direct reaction between ozone and phenol by high-gravity intensified heterogeneous catalytic ozonation.
基金This research was supported by National Natural Science Foundation of China grants(81971251,81671329,81871050,82171497,82101582,82001406)Clinical Research Center at Shanghai Mental Health Center grants(CRC2018ZD01,CRC2018ZD04,CRC2018YB01,CRC2019ZD02)+6 种基金Clinical Research Center at Shanghai Jiao Tong University School of Medicine(DLY201817,20190102)Shanghai Science and Technology Committee Foundations(19411950800,16ZR1430500,19411969100,19410710800,21ZR1481500,20ZR1448600,21S31903100,19ZR14451)Shanghai Clinical Research Center for Mental Health(19MC1911100)Project of the Key Discipline Construction,Shanghai 3-Year Public Health Action Plan(GWV-10.1-XK18)Shanghai Municipal Science and Technology Major Project(2018SHZDZX01,2018SHZDZX05)and ZJ LabFoundation of Shanghai Mental Health Center(2020-FX-02)Excellent Talents Training Project of Shanghai Municipal Commission of Health(GWV-10.2-YQ44).
文摘Background Disrupted white matter(WM)microstructure has been commonly identified in youth at clinical high risk(CHR)for psychosis.Several lines of evidence suggest that fatty acids,especially unsaturated fatty acids(UFAs),might play a crucial role in the WM pathology of early onset psychosis.However,evidence linking UFA and WM microstructure in CHR is quite sparse.Aims We investigated the relationship between the plasma UFA level and WM microstructure in CHR participants and healthy controls(HC).Methods Plasma fatty acids were assessed and diffusion tensor imaging(DTI)data were performed with tract-based spatial statistics(TBSS)analysis for 66 individuals at CHR for psychosis and 70 HC.Results Both the global and regional diffusion measures showed significant between-group differences,with decreased fractional anisotropy(FA)but increased mean diffusivity(MD)and radial diffusivity(RD)found in the CHR group compared with the HC group.On top of that,we found that in the HC group,plasma arachidic acid showed obvious trend-level associations with higher global FA,lower global MD and lower global RD,which regionally spread over the corpus callosum,right anterior and superior corona radiata,bilateral anterior and posterior limb of the internal capsule,and bilateral superior longitudinal fasciculus.However,there were no associations between global WM measures and any UFA in the CHR group.Conversely,we even found negative associations between arachidic acid levels and regional FA values in the right superior longitudinal fasciculus and right retrolenticular part of the internal capsule in the CHR group.Conclusions Compared with the HC group,CHR subjects exhibited a different pattern of association between WM microstructure and plasma UFA,with a neuroprotective effect found in the HC group but not in the CHR group.Such discrepancy could be due to the excessively upregulated UFAs accumulated in the plasma of the CHR group,highlighting the role of balanced plasma-membrane fatty acids homeostasis in WM development.
基金National Key Research and Development Program of China,Grant/Award Number:2016YFB1000905the State Key Ptogtam of National Nature Science Foundatioii of China,Grant/Award Numbet:61936001。
文摘Relation extraction between entity pairs is an increasingly critical area in natural language processing.Recently the pre-trained bidirectional encoder representation from transformer(BERT)performs excellendy on the text classification or sequence labelling tasks.Here,the high-level syntactic features that consider the dependency between each word and the target entities into the pre-trained language models are incorporated.Our model also utilizes the intermediate layers of BERT to acquire different levels of semantic information and designs multi-granularity features for final relation classification.Our model offers a momentous improvement over the published methods for the relation extraction on the widely used data sets.
基金This work was financially supported by National Natural Science Foundation of China(No.U1860204)the Fundamental Research Funds for the Central Universities(No.N172507002)the Transformation Project of Major Scientific and Technological Achievements in Shenyang(No.Z17-5-003).
文摘The influence of N on the precipitation behavior,associated corrosion,and mechanical properties of S32654 were investigated by microstructural,electrochemical,and mechanical analyses.Increasing the N content results in several alterations:(1) grain refinement,which promotes intergranular precipitation;(2) a linear increase in the driving force for Cr2 N and Mo activity,which accelerates the precipitation of intergranular Cr2 N and π phase,respectively;(3) a linear decrease in the driving force for σ phase and Cr activity,which suppresses the formation of intragranular σ phase.The total amount of precipitates first decreased and then increased with the N content increasing.Furthermore,the intergranular corrosion susceptibility depended substantially on the total amount of precipitates and also first exhibited a decreasing and then an increasing trend as the N content increased.In addition,aging precipitation caused a considerable decrement in the ultimate tensile strength(UTS) and a remarkable increment in the yield strength(YS).Both the UTS and YS always increased with N content increasing throughout the solution and aging process.Whereas the elongation was considerably sensitive to the aging treatment,it exhibited marginal variation with the N content increasing.
基金This work was supported by the Fund for Shanxi"1331Project"(Grant No.nuc2021-006),Scientific Activities of Selected Returned Overseas Professionals in Shanxi Province(Grant No.20200004)Shanxi Scholarship Council of China(Grant No.2019032).
文摘The application of iron–carbon(Fe–C)micro-electrolysis to wastewater treatment is limited by the passivation potential of the Fe–C packing.In order to address this problem,high-gravity intensified Fe–C micro-electrolysis was proposed in this study for degradation of dinitrotoluene wastewater in a rotating packed bed(RPB)using commercial Fe–C particles as the packing.The effects of reaction time,high-gravity factor,liquid flow rate and initial solution pH were investigated.The degradation intermediates were determined by gas chromatography-mass spectrometry,and the possible degradation pathways of nitro compounds by Fe–C micro-electrolysis in RPB were also proposed.It is found that under optimal conditions,the removal rate of nitro compounds reaches 68.4%at 100 min.The removal rate is maintained at approximately 68%after 4 cycles in RPB,but it is decreased substantially from 57.9%to 36.8%in a stirred tank reactor.This is because RPB can increase the specific surface area and the renewal of the liquid–solid interface,and as a result the degradation efficiency of Fe–C micro-electrolysis is improved and the active sites on the Fe–C surface can be regenerated for continuous use.In conclusion,high-gravity intensified Fe–C micro-electrolysis can weaken the passivation of Fe–C particles and extend their service life.
文摘Aeromonas sobria,a Gram-negative bacterium that can colonize both humans and animals,is found in a variety of environments,including water,seafood,meat,and vegetables(Cahill,1990;Galindo et al.,2004;Song et al,2019).Aeromonas spp.are conditionally pathogenic bacteria in aquaculture,which can rapidly proliferate,causing disease and even death in fish,especially when the environment is degraded(Neamat-Allah et al,2020,2021a,2021b).In developing countries,Aeromonas spp.have been associated with a wide spectrum of infections in humans,including gastroen-teritis,wound infections,septicemia,and lung infections(San Joaquin and Pickett,1988;Wang et al,2009;Su et al,2013).Infections caused by Aeromonas spp.are usually more severe in immunocompromised individuals(Miyamoto et al,2017).
基金The research was supported by the National Natural Science Foundation of China (Grant Nos. 61432020, 61303064, 61472430, 61502512) and National Grand R&D Plan (2016YFB 1000805).
文摘Internet-scale open source software (OSS) pro- duction in various communities generates abundant reusable resources for software developers. However, finding the de- sired and mature software with keyword queries from a considerable number of candidates, especially for the fresher, is a significant challenge because current search services often fail to understand the semantics of user queries. In this paper, we construct a software term database (STDB) by analyzing tagging data in Stack Overflow and propose a correlationbased software search (CBSS) approach that performs correlation retrieval based on the term relevance obtained from STDB. In addition, we design a novel ranking method to optimize the initial retrieval result. We explore four research questions in four experiments, respectively, to evaluate the effectiveness of the STDB and investigate the performance of the CBSS. The experiment results show that the proposed CBSS can effectively respond to keyword-based software searches and significantly outperforms other existing search services at finding mature software.
基金Supported by National Key Research and Development Program of China(2021YFC2301604)Chinese Postdoctoral Science Foundation(2020T130020ZX)+1 种基金the Science and Technology Program of Guangzhou(202102021285)Innovation and Development Project of China Meteorological Administration(CXFZ2021J045).
文摘Introduction:With the large-scale roll-out of the coronavirus disease 2019(COVID-19)booster vaccination effort(a vaccine dose given 6 months after completing primary vaccination)in China,we explore when and how China could lift non-pharmacological interventions(NPIs)against COVID-19 in 2022.Methods:Using a modified susceptible-infectiousrecovered(SIR)mathematical model,we projected the COVID-19 epidemic situation and required medical resources in Guangdong Province,China.Results:If the number of people entering from overseas recovers to 20%of the number in 2019,the epidemic in 2022 could be controlled at a low level by a containment(215 local cases)or suppression strategy(1,397 local cases).A mitigation strategy would lead to 21,722 local cases.A coexistence strategy would lead to a large epidemic with 6,850,083 local cases that would overwhelm Guangdong’s medical system.With 50%or 100%recovery of the 2019 level of travelers from overseas,the epidemic could also be controlled with containment or suppression,but enormous resources,including more hotel rooms for border quarantine,will be required.However,coexistence would lead to an uncontrollable epidemic with 12,922,032 local cases.Discussion:With booster vaccinations,the number of travelers from overseas could increase slightly in 2022,but a suppression strategy would need to be maintained to ensure a controllable epidemic.