Anticipating the imminent surge of retired lithium-ion batteries(R-LIBs)from electric vehicles,the need for safe,cost-effective and environmentally friendly disposal technologies has escalated.This paper seeks to offe...Anticipating the imminent surge of retired lithium-ion batteries(R-LIBs)from electric vehicles,the need for safe,cost-effective and environmentally friendly disposal technologies has escalated.This paper seeks to offer a comprehensive overview of the entire disposal framework for R-LIBs,encompassing a broad spectrum of activities,including screening,repurposing and recycling.Firstly,we delve deeply into a thorough examination of current screening technologies,shifting the focus from a mere enumeration of screening methods to the exploration of the strategies for enhancing screening efficiency.Secondly,we outline battery repurposing with associated key factors,summarizing stationary applications and sizing methods for R-LIBs in their second life.A particular light is shed on available reconditioning solutions,demonstrating their great potential in facilitating battery safety and lifetime in repurposing scenarios and identifying their techno-economic issues.In the realm of battery recycling,we present an extensive survey of pre-treatment options and subsequent material recovery technologies.Particularly,we introduce several global leading recyclers to illustrate their industrial processes and technical intricacies.Furthermore,relevant challenges and evolving trends are investigated in pursuit of a sustainable end-of-life management and disposal framework.We hope that this study can serve as a valuable resource for researchers,industry professionals and policymakers in this field,ultimately facilitating the adoption of proper disposal practices.展开更多
Tax risk behavior causes serious loss of fiscal revenue,damages the country’s public infrastructure,and disturbs the market economic order of fair competition.In recent years,tax risk detection,driven by information ...Tax risk behavior causes serious loss of fiscal revenue,damages the country’s public infrastructure,and disturbs the market economic order of fair competition.In recent years,tax risk detection,driven by information technology such as data mining and artificial intelligence,has received extensive attention.To promote the high-quality development of tax risk detection methods,this paper provides the first comprehensive overview and summary of existing tax risk detection methods worldwide.More specifi-cally,it first discusses the causes and negative impacts of tax risk behaviors,along with the development of tax risk detection.It then focuses on data-mining-based tax risk detection methods utilized around the world.Based on the different principles employed by the algorithms,existing risk detection methods can be divided into two categories:relationship-based and non-relationship-based.A total of 14 risk detection methods are identified,and each method is thoroughly explored and analyzed.Finally,four major technical bottlenecks of current data-driven tax risk detection methods are analyzed and discussed,including the difficulty of integrating and using fiscal and tax fragmented knowledge,unexplainable risk detection results,the high cost of risk detection algorithms,and the reliance of existing algorithms on labeled information.After investigating these issues,it is concluded that knowledge-guided and datadriven big data knowledge engineering will be the development trend in the field of tax risk in the future;that is,the gradual transition of tax risk detection from informatization to intelligence is the future development direction.展开更多
Glycine is a well-documented cytoprotective agent.However,whether it has a protective effect against myocar-dial ischemia-reperfusion injury in vivo is still unknown.By using an open-chest anesthetized rat model,we fo...Glycine is a well-documented cytoprotective agent.However,whether it has a protective effect against myocar-dial ischemia-reperfusion injury in vivo is still unknown.By using an open-chest anesthetized rat model,we found that glycine reduced the infarct size by 21% in ischemia-reperfusion injury rats compared with that in the vehicle-treated MI/R rats.The left ventricular ejection fraction and fractional shortening were increased by 19.11% and 30.98%,respectively,in glycine-treated rats.The plasma creatine kinase levels in ischemia-reperfusion injury rats decreased following glycine treatment.Importantly,administration of glycine significantly inhibited apoptosis in post-ischemia-reperfusion myocardium,which was accompanied by suppression of phosphorylated p38 mitogen-activated protein kinase and c-Jun NH2-terminal kinase,as well as the Fas ligand.These results suggest that gly-cine attenuates myocardial ischemia-reperfusion injury in vivo by inhibiting cardiomyocytes apoptosis.展开更多
Cartilage-targeting delivery of therapeutic agents is still an effective strategy for osteoarthritis(OA)therapy.Recently,scavenging for reactive oxygen species(ROS)and activating autophagy have been increasingly repor...Cartilage-targeting delivery of therapeutic agents is still an effective strategy for osteoarthritis(OA)therapy.Recently,scavenging for reactive oxygen species(ROS)and activating autophagy have been increasingly reported to treat OA effectively.In this study,we designed,for the first time,a dual-drug delivery system based on metal organic framework(MOF)-decorated mesoporous polydopamine(MPDA)which composed of rapamycin(Rap)loaded into the mesopores and bilirubin(Br)loaded onto the shell of MOF.The collagen II-targeting peptide(WYRGRL)was then conjugated on the surface of above nanocarrier to develop a cartilage-targeting dual-drug delivery nanoplatform(RB@MPMW).Our results indicated the sequential release of two agents from RB@MPMW could be achieved via near-infrared(NIR)laser irritation.Briefly,the rapid release of Br from the MOF shell exhibited excellent ROS scavenging ability and anti-apoptosis effects,however responsively reduced autophagy activity,to a certain extent.Meanwhile,following the NIR irradiation,Rap was rapidly released from MPDA core and further enhanced autophagy activation and chondrocyte protection.RB@MPMW continuously phosphorylated AMPK and further rescued mitochondrial energy metabolism of chondrocytes following IL-1βstimulation via activating SIRT1-PGC-1αsignaling pathway.Additionally,the cartilage-targeting property of peptide-modified nanocarrier could be monitored via Magnetic Resonance(MR)and IVIS imaging.More significantly,RB@MPMW effectively delayed cartilage degeneration in ACLT rat model.Overall,our findings indicated that the as-prepared dual-drug delivery nanoplatform exerted potent anti-inflammation and anti-apoptotic effects,rescued energy metabolism of chondrocytes in vitro and prevented cartilage degeneration in vivo,which thereby showed positive performance for OA therapy.展开更多
Nickel (hydr)oxide (NiOH) is known to be good co-catalyst for the photoelectrochemical oxidation of water,and for the photocatalytic oxidation of organics on different semiconductors.Herein we report a greatly improve...Nickel (hydr)oxide (NiOH) is known to be good co-catalyst for the photoelectrochemical oxidation of water,and for the photocatalytic oxidation of organics on different semiconductors.Herein we report a greatly improved activity of Bi_(2)MoO_(6)(BMO) by nickel hexammine perchlorate (NiNH).Under visible light,phenol oxidation on BMO was slow.After NiNH,NiOH,and Ni^(2+)loading,a maximum rate of phenol oxidation increased by factors of approximately 16,8.8,and 4.7,respectively.With a BMO electrode,all catalysts inhibited O_(2)reduction,enhanced water (photo-)oxidation,and facilitated the charge transfer at solidliquid interface,respectively,the degree of which was always NiNH>NiOH>Ni^(2+).Solid emission spectra indicated that all catalysts improved the charge separation of BMO,the degree of which also varied as NiNH>NiOH>Ni^(2+).Furthermore,after a phenol-free aqueous suspension of NiNH/BMO was irradiated,there was a considerable Ni(Ⅲ) species,but a negligible NH_(2)radical.Accordingly,a plausible mechanism is proposed,involving the hole oxidation of Ni(Ⅱ) into Ni(Ⅳ),which is reactive to phenol oxidation,and hence promotes O_(2)reduction.Because NH_(3)is a stronger ligand than H_(2)O,the Ni(Ⅱ) oxidation is easier for Ni(NH_(3))6+than for Ni(H_(2)O)6+.This work shows a simple route how to improve BMO photocatalysis through a co-catalyst.展开更多
Purpose–It would take billions of miles’field road testing to demonstrate that the safety of automated vehicle is statistically significantly higher than the safety of human driving because that the accident of vehi...Purpose–It would take billions of miles’field road testing to demonstrate that the safety of automated vehicle is statistically significantly higher than the safety of human driving because that the accident of vehicle is rare event.Design/methodology/approach–This paper proposes an accelerated testing method for automated vehicles safety evaluation based on improved importance sampling(IS)techniques.Taking the typical cut-in scenario as example,the proposed method extracts the critical variables of the scenario.Then,the distributions of critical variables are statistically fitted.The genetic algorithm is used to calculate the optimal IS parameters by solving an optimization problem.Considering the error of distribution fitting,the result is modified so that it can accurately reveal the safety benefits of automated vehicles in the real world.Findings–Based on the naturalistic driving data in Shanghai,the proposed method is validated by simulation.The result shows that compared with the existing methods,the proposed method improves the test efficiency by 35 per cent,and the accuracy of accelerated test result is increased by 23 per cent.Originality/value–This paper has three contributions.First,the genetic algorithm is used to calculate IS parameters,which improves the efficiency of test.Second,the result of test is modified by the error correction parameter,which improves the accuracy of test result.Third,typical high-risk cut-in scenarios in China are analyzed,and the proposed method is validated by simulation.展开更多
To the Editor:Total knee arthroplasty(TKA)has became an established treatment for end-stage joint disease.In China,there was a 5.9-fold increase in the number of TKA cases between 2011 and 2019.All kinds of infections...To the Editor:Total knee arthroplasty(TKA)has became an established treatment for end-stage joint disease.In China,there was a 5.9-fold increase in the number of TKA cases between 2011 and 2019.All kinds of infections are catastrophic complications of TKA.Recent reports have highlighted the underestimated prevalence of surgical site infections(SSIs)and projected an increase in complex SSIs following hip and knee arthroplasties by 14%between 2020 and 2030.^([1])However,there are few reports describing SSIs in Chinese population.This preliminary retrospective study aimed to gain some insights into the occurrence,risk factors,and microbiological patterns of SSIs in China.展开更多
A rapid reaction occurs near the exhaust nozzle when vehicle emissions contact the air.Twenty diesel vehicles were studied using a new multipoint sampling system that is suitable for studying the exhaust plume near th...A rapid reaction occurs near the exhaust nozzle when vehicle emissions contact the air.Twenty diesel vehicles were studied using a new multipoint sampling system that is suitable for studying the exhaust plume near the exhaust nozzle.The variation characteristics of fine particle matter(PM_(2.5)) and its components in diesel vehicle exhaust plumes were analyzed.The PM_(2.5) emissions gradually increased with increasing distance from the nozzle in the plume.Elemental carbon emissions remained basically unchanged, organic carbon and total carbon(TC) increased with increasing distance.The concentrations of SO_(4)^(2-),NO_(3)^(-) and NH_(4)^(+) (SNA) directly emitted by the vehicles were very low but increased rapidly in the exhaust plume.The selective catalytic reduction(SCR) reduced 42.7% TC, 40% NO_(3)^(-) emissions, but increased 104% SO_(4)^(2-) and 36% NH_(4)^(+) emissions, respectively.In summary,the SCR reduced 29% primary PM_(2.5) emissions for the tested diesel vehicles.The NH_(4)NO_(3) particle formation maybe more important in the plume, and there maybe other forms of formation of NH_(4)^(+) (eg.NH4Cl).The generation of secondary organic carbon(SOC) plays a leading role in the generation of secondary PM_(2.5).The SCR enhanced the formation of SOC and SNA in the plume, but comprehensive analysis shows that the SCR more enhanced the SNA formation in the plume, which is mainly new particles formation process.The inconsistency between secondary organic aerosol(SOA) and primary organic aerosol definitions is one of the important reasons for the difference between SOA simulation and observation.展开更多
Magnetoelectric(ME)materials have caught worldwide attentions owing to their potential technological applications in ME switching devices or high-density data storage.However,realizing a sufficiently strong ME effect ...Magnetoelectric(ME)materials have caught worldwide attentions owing to their potential technological applications in ME switching devices or high-density data storage.However,realizing a sufficiently strong ME effect in one single material is always the key issue.Herein,we systematically investigate the Co_(3)NiNb_(2)O_(9),including the characterization of its crystalline structure,magnetism,specific heat,and pyroelectric properties.It is revealed that Co_(3)NiNb_(2)O_(9) exhibits a remarkable ME response below the magnetic phase transition temperature of TN-32 K.On one hand,the magnetic field-induced electric polarization is observed below TN while it is non-ferroelectric at no magnetic field.The evaluated ME coefficient is as large as 21.2 ps/m.On the other hand,the magnetization is significantly modulated by the applied electric field,with the inverse ME coefficient being 14.1 ps/m.The observed ME responses suggest a stable ME mutual control by the magnetic or electric field in Co_(3)NiNb_(2)O_(9).展开更多
In response to contraction during exercise,skeletal muscle growth and metabolism are dynamically regulated by nerve action,blood flow,and metabolic feedback.α-Ketoglutarate(AKG),a bioactive intermediate in the tricar...In response to contraction during exercise,skeletal muscle growth and metabolism are dynamically regulated by nerve action,blood flow,and metabolic feedback.α-Ketoglutarate(AKG),a bioactive intermediate in the tricarboxylic acid cycle released during exercise,has been shown to promote skeletal muscle hypertrophy.However,the underlying mechanism of AKG in regulating skeletal muscle development and metabolism is still less known.2-Oxoglutarate receptor 1(OXGR1),the endogenous AKG receptor,is found to be distributed in the vascular smooth muscle(VSM)of skeletal muscles.OXGR1 knockout results in skeletal muscle atrophy,accompanied by decreased expression of myosin heavy chain I(MyHC I),capillary density,and endurance exercise capacity.Furthermore,the study found that dietary AKG supplementation increased mice endurance exercise distance,MyHC I/MyHC IIb ratio,arteriole,and capillary densities in skeletal muscle.Meanwhile,acute AKG administration gradually increased the blood flow in the lower limbs.Further,by using OXGR1 global knockout and OXGR1 VSM-specific(MYH11-Cre×OXGR1-FloxP)knockdown models,we found that OXGR1 in VSM is essential for AKG-induced improvement of skeletal muscle performances.According to the in vitro study,AKG expanded the cell area in VSM with a decreased intracellular pH by OXGR1.Our results demonstrated a novel role of AKG/OXGR1 in VSM of skeletal muscle to regulate blood flow and then enhance slow muscle fiber conversion and capillarization.These findings provide a theoretical basis for the AKG/OXGR1 signaling pathway to maintain human muscle function and improve meat production and livestock and poultry meat quality.展开更多
Hypocrellin B (HB) is a highly effective photosensitizer. One of its derivatives, 5_brominated_hypocrellin B (5_Br_HB) has better photosensitive characteristics than it. Using Raman spectroscopy, the microcosmic photo...Hypocrellin B (HB) is a highly effective photosensitizer. One of its derivatives, 5_brominated_hypocrellin B (5_Br_HB) has better photosensitive characteristics than it. Using Raman spectroscopy, the microcosmic photodamage to DNA sensitized by HB and 5_Br_HB was studied at molecular level. The results showed that when HB and 5_Br_HB were added to the solution of DNA and irradiated, the characteristic Raman frequencies and intensities of DNA changed to various degrees. The photodamage occurred on the whole DNA molecule, including phosphate backbone,deoxyribose and four bases. Not only the conformation but also the configuration of DNA was photodamaged: breakage of some H_bonds, disappearance of B_form conformation , scission of double or single strand and serious damage of four bases. The damage to A_T pairs was stronger than that to C_G pairs and DNA became polynucleotides finally. The 5_Br_HB_photosensitized damage to DNA was stronger than HB , which suggested the better photosensitive characteristics of 5_Br_HB in bioactive environment. The molecular mechanisms of photodamage to DNA sensitized by 5_Br_HB and HB were also elucidated.展开更多
基金supported by an Australian Government Research Training Program Scholarship offered to the first author of this study。
文摘Anticipating the imminent surge of retired lithium-ion batteries(R-LIBs)from electric vehicles,the need for safe,cost-effective and environmentally friendly disposal technologies has escalated.This paper seeks to offer a comprehensive overview of the entire disposal framework for R-LIBs,encompassing a broad spectrum of activities,including screening,repurposing and recycling.Firstly,we delve deeply into a thorough examination of current screening technologies,shifting the focus from a mere enumeration of screening methods to the exploration of the strategies for enhancing screening efficiency.Secondly,we outline battery repurposing with associated key factors,summarizing stationary applications and sizing methods for R-LIBs in their second life.A particular light is shed on available reconditioning solutions,demonstrating their great potential in facilitating battery safety and lifetime in repurposing scenarios and identifying their techno-economic issues.In the realm of battery recycling,we present an extensive survey of pre-treatment options and subsequent material recovery technologies.Particularly,we introduce several global leading recyclers to illustrate their industrial processes and technical intricacies.Furthermore,relevant challenges and evolving trends are investigated in pursuit of a sustainable end-of-life management and disposal framework.We hope that this study can serve as a valuable resource for researchers,industry professionals and policymakers in this field,ultimately facilitating the adoption of proper disposal practices.
基金supported by the Key Research and Development Project in Shaanxi Province (2023GXLH-024)the National Natural Science Foundation of China (62250009,62002282,62037001,and 62192781).
文摘Tax risk behavior causes serious loss of fiscal revenue,damages the country’s public infrastructure,and disturbs the market economic order of fair competition.In recent years,tax risk detection,driven by information technology such as data mining and artificial intelligence,has received extensive attention.To promote the high-quality development of tax risk detection methods,this paper provides the first comprehensive overview and summary of existing tax risk detection methods worldwide.More specifi-cally,it first discusses the causes and negative impacts of tax risk behaviors,along with the development of tax risk detection.It then focuses on data-mining-based tax risk detection methods utilized around the world.Based on the different principles employed by the algorithms,existing risk detection methods can be divided into two categories:relationship-based and non-relationship-based.A total of 14 risk detection methods are identified,and each method is thoroughly explored and analyzed.Finally,four major technical bottlenecks of current data-driven tax risk detection methods are analyzed and discussed,including the difficulty of integrating and using fiscal and tax fragmented knowledge,unexplainable risk detection results,the high cost of risk detection algorithms,and the reliance of existing algorithms on labeled information.After investigating these issues,it is concluded that knowledge-guided and datadriven big data knowledge engineering will be the development trend in the field of tax risk in the future;that is,the gradual transition of tax risk detection from informatization to intelligence is the future development direction.
基金supported by the National Natural Science Foundation of China(No.81070120,81000118 and 81100857)the National Basic Research Program(973 Program,No.2012CB517503 and 2011CB503903)
文摘Glycine is a well-documented cytoprotective agent.However,whether it has a protective effect against myocar-dial ischemia-reperfusion injury in vivo is still unknown.By using an open-chest anesthetized rat model,we found that glycine reduced the infarct size by 21% in ischemia-reperfusion injury rats compared with that in the vehicle-treated MI/R rats.The left ventricular ejection fraction and fractional shortening were increased by 19.11% and 30.98%,respectively,in glycine-treated rats.The plasma creatine kinase levels in ischemia-reperfusion injury rats decreased following glycine treatment.Importantly,administration of glycine significantly inhibited apoptosis in post-ischemia-reperfusion myocardium,which was accompanied by suppression of phosphorylated p38 mitogen-activated protein kinase and c-Jun NH2-terminal kinase,as well as the Fas ligand.These results suggest that gly-cine attenuates myocardial ischemia-reperfusion injury in vivo by inhibiting cardiomyocytes apoptosis.
基金supported by the National Natural Science Foundation of China(81871795,31771048 and 81702124)Shanghai Municipal Health and Family Planning Commission(SHDC12017121)+1 种基金Medical Engineering Cross Research Project of Shanghai Jiaotong University(YG2019QNB37)Songjiang District Science and Technology Research project(18sjkjgg18).
文摘Cartilage-targeting delivery of therapeutic agents is still an effective strategy for osteoarthritis(OA)therapy.Recently,scavenging for reactive oxygen species(ROS)and activating autophagy have been increasingly reported to treat OA effectively.In this study,we designed,for the first time,a dual-drug delivery system based on metal organic framework(MOF)-decorated mesoporous polydopamine(MPDA)which composed of rapamycin(Rap)loaded into the mesopores and bilirubin(Br)loaded onto the shell of MOF.The collagen II-targeting peptide(WYRGRL)was then conjugated on the surface of above nanocarrier to develop a cartilage-targeting dual-drug delivery nanoplatform(RB@MPMW).Our results indicated the sequential release of two agents from RB@MPMW could be achieved via near-infrared(NIR)laser irritation.Briefly,the rapid release of Br from the MOF shell exhibited excellent ROS scavenging ability and anti-apoptosis effects,however responsively reduced autophagy activity,to a certain extent.Meanwhile,following the NIR irradiation,Rap was rapidly released from MPDA core and further enhanced autophagy activation and chondrocyte protection.RB@MPMW continuously phosphorylated AMPK and further rescued mitochondrial energy metabolism of chondrocytes following IL-1βstimulation via activating SIRT1-PGC-1αsignaling pathway.Additionally,the cartilage-targeting property of peptide-modified nanocarrier could be monitored via Magnetic Resonance(MR)and IVIS imaging.More significantly,RB@MPMW effectively delayed cartilage degeneration in ACLT rat model.Overall,our findings indicated that the as-prepared dual-drug delivery nanoplatform exerted potent anti-inflammation and anti-apoptotic effects,rescued energy metabolism of chondrocytes in vitro and prevented cartilage degeneration in vivo,which thereby showed positive performance for OA therapy.
基金supported by the Funds for Creative Research Group of NSFC (No.21621005)。
文摘Nickel (hydr)oxide (NiOH) is known to be good co-catalyst for the photoelectrochemical oxidation of water,and for the photocatalytic oxidation of organics on different semiconductors.Herein we report a greatly improved activity of Bi_(2)MoO_(6)(BMO) by nickel hexammine perchlorate (NiNH).Under visible light,phenol oxidation on BMO was slow.After NiNH,NiOH,and Ni^(2+)loading,a maximum rate of phenol oxidation increased by factors of approximately 16,8.8,and 4.7,respectively.With a BMO electrode,all catalysts inhibited O_(2)reduction,enhanced water (photo-)oxidation,and facilitated the charge transfer at solidliquid interface,respectively,the degree of which was always NiNH>NiOH>Ni^(2+).Solid emission spectra indicated that all catalysts improved the charge separation of BMO,the degree of which also varied as NiNH>NiOH>Ni^(2+).Furthermore,after a phenol-free aqueous suspension of NiNH/BMO was irradiated,there was a considerable Ni(Ⅲ) species,but a negligible NH_(2)radical.Accordingly,a plausible mechanism is proposed,involving the hole oxidation of Ni(Ⅱ) into Ni(Ⅳ),which is reactive to phenol oxidation,and hence promotes O_(2)reduction.Because NH_(3)is a stronger ligand than H_(2)O,the Ni(Ⅱ) oxidation is easier for Ni(NH_(3))6+than for Ni(H_(2)O)6+.This work shows a simple route how to improve BMO photocatalysis through a co-catalyst.
基金The authors would like to thank the Natural Science Foundation of China(U1764261,51422812)the Shanghai Science and technology project of international cooperation(16510711400)for supporting this research.
文摘Purpose–It would take billions of miles’field road testing to demonstrate that the safety of automated vehicle is statistically significantly higher than the safety of human driving because that the accident of vehicle is rare event.Design/methodology/approach–This paper proposes an accelerated testing method for automated vehicles safety evaluation based on improved importance sampling(IS)techniques.Taking the typical cut-in scenario as example,the proposed method extracts the critical variables of the scenario.Then,the distributions of critical variables are statistically fitted.The genetic algorithm is used to calculate the optimal IS parameters by solving an optimization problem.Considering the error of distribution fitting,the result is modified so that it can accurately reveal the safety benefits of automated vehicles in the real world.Findings–Based on the naturalistic driving data in Shanghai,the proposed method is validated by simulation.The result shows that compared with the existing methods,the proposed method improves the test efficiency by 35 per cent,and the accuracy of accelerated test result is increased by 23 per cent.Originality/value–This paper has three contributions.First,the genetic algorithm is used to calculate IS parameters,which improves the efficiency of test.Second,the result of test is modified by the error correction parameter,which improves the accuracy of test result.Third,typical high-risk cut-in scenarios in China are analyzed,and the proposed method is validated by simulation.
文摘To the Editor:Total knee arthroplasty(TKA)has became an established treatment for end-stage joint disease.In China,there was a 5.9-fold increase in the number of TKA cases between 2011 and 2019.All kinds of infections are catastrophic complications of TKA.Recent reports have highlighted the underestimated prevalence of surgical site infections(SSIs)and projected an increase in complex SSIs following hip and knee arthroplasties by 14%between 2020 and 2030.^([1])However,there are few reports describing SSIs in Chinese population.This preliminary retrospective study aimed to gain some insights into the occurrence,risk factors,and microbiological patterns of SSIs in China.
基金supported by the National Natural Science Foundation of China (No.41605095)the Beijing Natural Science Foundation (No.JQ19030)+1 种基金the Beijing Municipal Commission of Education (No.PXM2019014213000007)the School Level Cultivation Fund of Beijing Technology and Business University for Distinguished and Excellent Young Scholars (No.BTBUYP2020)。
文摘A rapid reaction occurs near the exhaust nozzle when vehicle emissions contact the air.Twenty diesel vehicles were studied using a new multipoint sampling system that is suitable for studying the exhaust plume near the exhaust nozzle.The variation characteristics of fine particle matter(PM_(2.5)) and its components in diesel vehicle exhaust plumes were analyzed.The PM_(2.5) emissions gradually increased with increasing distance from the nozzle in the plume.Elemental carbon emissions remained basically unchanged, organic carbon and total carbon(TC) increased with increasing distance.The concentrations of SO_(4)^(2-),NO_(3)^(-) and NH_(4)^(+) (SNA) directly emitted by the vehicles were very low but increased rapidly in the exhaust plume.The selective catalytic reduction(SCR) reduced 42.7% TC, 40% NO_(3)^(-) emissions, but increased 104% SO_(4)^(2-) and 36% NH_(4)^(+) emissions, respectively.In summary,the SCR reduced 29% primary PM_(2.5) emissions for the tested diesel vehicles.The NH_(4)NO_(3) particle formation maybe more important in the plume, and there maybe other forms of formation of NH_(4)^(+) (eg.NH4Cl).The generation of secondary organic carbon(SOC) plays a leading role in the generation of secondary PM_(2.5).The SCR enhanced the formation of SOC and SNA in the plume, but comprehensive analysis shows that the SCR more enhanced the SNA formation in the plume, which is mainly new particles formation process.The inconsistency between secondary organic aerosol(SOA) and primary organic aerosol definitions is one of the important reasons for the difference between SOA simulation and observation.
基金supported by the National Key Research Projects of China[Grant No.2016YFA0300101]the National Natural Science Foundation of China[Grant Nos.12074111,11804088,11704109,51431006]the Research Project of Hubei Provincial Department of Education[Grant No.B2018146].
文摘Magnetoelectric(ME)materials have caught worldwide attentions owing to their potential technological applications in ME switching devices or high-density data storage.However,realizing a sufficiently strong ME effect in one single material is always the key issue.Herein,we systematically investigate the Co_(3)NiNb_(2)O_(9),including the characterization of its crystalline structure,magnetism,specific heat,and pyroelectric properties.It is revealed that Co_(3)NiNb_(2)O_(9) exhibits a remarkable ME response below the magnetic phase transition temperature of TN-32 K.On one hand,the magnetic field-induced electric polarization is observed below TN while it is non-ferroelectric at no magnetic field.The evaluated ME coefficient is as large as 21.2 ps/m.On the other hand,the magnetization is significantly modulated by the applied electric field,with the inverse ME coefficient being 14.1 ps/m.The observed ME responses suggest a stable ME mutual control by the magnetic or electric field in Co_(3)NiNb_(2)O_(9).
基金This work was supported by the Major Program of the National Natural Science Foundation of China(31790411 to Q.J.)The Local Innovative and Research Teams Project of Guangdong Province(2019BT02N630 to G.S.)+1 种基金Guangdong Laboratory for Lingnan Modern Agricultural Project(NZ2021028)National Natural Science Foundation of China(31972636 to S.W.).
文摘In response to contraction during exercise,skeletal muscle growth and metabolism are dynamically regulated by nerve action,blood flow,and metabolic feedback.α-Ketoglutarate(AKG),a bioactive intermediate in the tricarboxylic acid cycle released during exercise,has been shown to promote skeletal muscle hypertrophy.However,the underlying mechanism of AKG in regulating skeletal muscle development and metabolism is still less known.2-Oxoglutarate receptor 1(OXGR1),the endogenous AKG receptor,is found to be distributed in the vascular smooth muscle(VSM)of skeletal muscles.OXGR1 knockout results in skeletal muscle atrophy,accompanied by decreased expression of myosin heavy chain I(MyHC I),capillary density,and endurance exercise capacity.Furthermore,the study found that dietary AKG supplementation increased mice endurance exercise distance,MyHC I/MyHC IIb ratio,arteriole,and capillary densities in skeletal muscle.Meanwhile,acute AKG administration gradually increased the blood flow in the lower limbs.Further,by using OXGR1 global knockout and OXGR1 VSM-specific(MYH11-Cre×OXGR1-FloxP)knockdown models,we found that OXGR1 in VSM is essential for AKG-induced improvement of skeletal muscle performances.According to the in vitro study,AKG expanded the cell area in VSM with a decreased intracellular pH by OXGR1.Our results demonstrated a novel role of AKG/OXGR1 in VSM of skeletal muscle to regulate blood flow and then enhance slow muscle fiber conversion and capillarization.These findings provide a theoretical basis for the AKG/OXGR1 signaling pathway to maintain human muscle function and improve meat production and livestock and poultry meat quality.
文摘Hypocrellin B (HB) is a highly effective photosensitizer. One of its derivatives, 5_brominated_hypocrellin B (5_Br_HB) has better photosensitive characteristics than it. Using Raman spectroscopy, the microcosmic photodamage to DNA sensitized by HB and 5_Br_HB was studied at molecular level. The results showed that when HB and 5_Br_HB were added to the solution of DNA and irradiated, the characteristic Raman frequencies and intensities of DNA changed to various degrees. The photodamage occurred on the whole DNA molecule, including phosphate backbone,deoxyribose and four bases. Not only the conformation but also the configuration of DNA was photodamaged: breakage of some H_bonds, disappearance of B_form conformation , scission of double or single strand and serious damage of four bases. The damage to A_T pairs was stronger than that to C_G pairs and DNA became polynucleotides finally. The 5_Br_HB_photosensitized damage to DNA was stronger than HB , which suggested the better photosensitive characteristics of 5_Br_HB in bioactive environment. The molecular mechanisms of photodamage to DNA sensitized by 5_Br_HB and HB were also elucidated.