In accordance with the pattern of"great ideology and politics",the Party and youth League organizations assume the role of vanguard in the organization of colleges and universities.Simultaneously,they serve ...In accordance with the pattern of"great ideology and politics",the Party and youth League organizations assume the role of vanguard in the organization of colleges and universities.Simultaneously,they serve as a pivotal force in ideological and political education.In order to construct a comprehensive ideological and political framework encompassing the entire educational process,it is of paramount importance to identify an efficacious methodology for Party building leading League construction.This paper employs a comprehensive analysis to elucidate the pivotal role of Party building leading League construction in facilitating ideological and political education.It also illuminates the practical challenges encountered in the implementation of Party building leading League construction initiatives within colleges and universities.The article proposes a specific path for Party building leading League construction in colleges and universities based on three key aspects:cohesion of the consensus of Party building leading League building,establishment of the institutional system of Party building leading League construction,and creation of the model brand of Party building leading League construction.The aim is to promote in-depth development of Party building in colleges and universities and enhance the quality and effect of ideological and political education.展开更多
The effects of the erosion present on the leading edge of a wind turbine airfoil(DU 96-W-180)on its aerodynamic performances have been investigated numerically in the framework of a SST k–ωturbulence model based on ...The effects of the erosion present on the leading edge of a wind turbine airfoil(DU 96-W-180)on its aerodynamic performances have been investigated numerically in the framework of a SST k–ωturbulence model based on the Reynolds Averaged Navier-Stokes equations(RANS).The results indicate that when sand-induced holes and small pits are involved as leading edge wear features,they have a minimal influence on the lift and drag coefficients of the airfoil.However,if delamination occurs in the same airfoil region,it significantly impacts the lift and resistance characteristics of the airfoil.Specifically,as the angle of attack grows,there is a significant decrease in the lift coefficient accompanied by a sharp increase in the drag coefficient.As wear intensifies,these effects gradually increase.Moreover,the leading edge wear can exacerbate flow separation near the trailing edge suction surface of the airfoil and cause forward displacement of the separation point.展开更多
Although covalent organic frameworks(COFs)with highπ-conjugation have recently exhibited great prospects in perovskite solar cells(PSCs),their further application in PSCs is still hindered by face-to-face stacking an...Although covalent organic frameworks(COFs)with highπ-conjugation have recently exhibited great prospects in perovskite solar cells(PSCs),their further application in PSCs is still hindered by face-to-face stacking and aggregation issues.Herein,metal-organic framework(MOF-808)is selected as an ideal platform for the in situ homogeneous growth of a COF to construct a core-shell MOF@COF nanoparticle,which could effectively inhibit COF stacking and aggregation.The synergistic intrinsic mechanisms induced by the MOF@COF nanoparticles for reinforcing intrinsic stability and mitigating lead leakage in PSCs have been explored.The complementary utilization ofπ-conjugated skeletons and nanopores could optimize the crystallization of large-grained perovskite films and eliminate defects.The resulting PSCs achieve an impressive power conversion efficiency of 23.61%with superior open circuit voltage(1.20 V)and maintained approximately 90%of the original power conversion efficiency after 2000 h(30-50%RH and 25-30℃).Benefiting from the synergistic effects of the in situ chemical fixation and adsorption abilities of the MOF@COF nanoparticles,the amount of lead leakage from unpackaged PSCs soaked in water(<5 ppm)satisfies the laboratory assessment required for the Resource Conservation and Recovery Act Regulation.展开更多
Drought events have become more frequent and intense over East Asia in recent decades,leading to huge socioeconomic impacts.Although the droughts have been studied extensively by cases or for individual regions,their ...Drought events have become more frequent and intense over East Asia in recent decades,leading to huge socioeconomic impacts.Although the droughts have been studied extensively by cases or for individual regions,their leading variability and associated causes remain unclear.Based on the Standardized Precipitation Evapotranspiration Index(SPEI)and ERA5 reanalysis product from 1979 to 2020,this study evealuates the severity of spring droughts in East Asia and investigates their variations and associated drivers.The results indicate that North China and Mongolia have experienced remarkable trends toward dryness during spring in recent decades,while southwestern China has witnessed an opposite trend toward wetness.The first Empirical Orthogonal Function mode of SPEI variability reveals a similar seesawing pattern,with more severe dryness in northwestern China,Mongolia,North China,South Korea,and Japan but increased wetness in Southwestern China and southeast Asia.Further investigation reveals that the anomalously dry(wet)surface in North(Southwestern)China is significantly associated with anomalously high(low)temperature,less(more)precipitation,and reduced(increased)soil moisture during the previous winter and early spring,regulated by an anomalous anticyclone(cyclone)and thus reduced(increased)water vapor convergence.The spring dry-wet pattern in East Asia is also linked to cold sea surface temperature anomalies in the central-eastern Pacific.The findings of this study have important implications for improving the prediction of spring drought events in East Asia.展开更多
Both, the dilemma to find a quantum field theory consistent with Einstein’s law of relativity and the problem to describe existing particles as bound states of matter has been solved by calculating bound state matrix...Both, the dilemma to find a quantum field theory consistent with Einstein’s law of relativity and the problem to describe existing particles as bound states of matter has been solved by calculating bound state matrix elements from a dual fermion-boson Lagrangian. In this formalism, the fermion binding energies are compensated by boson energies, indicating that particles can be generated out of the vacuum. This yields quantitative solutions for various mesons ω (0.78 GeV) - Υ (9.46 GeV) and all leptons e, μ and τ, with uncertainties in the extracted properties of less than 1‰. For transparency, a Web-page with the address htpps://h2909473.stratoserver.net has been constructed, where all calculations can be run on line and also the underlying fortran source code can be inspected.展开更多
Starting from the Simplified Navier-Stokes(SNS)equations presented at first by Godovachev-Kuzmin-Tsopov,and Gao Zhi,Davis,the authors analyze the character of the SNS equations for the laminarflow near the leading edg...Starting from the Simplified Navier-Stokes(SNS)equations presented at first by Godovachev-Kuzmin-Tsopov,and Gao Zhi,Davis,the authors analyze the character of the SNS equations for the laminarflow near the leading edge of a flat plate and far away from the plate by using the Weiner—Hopf meth-od and Fourier transform.It is proved that the solution of the SNS equations agree with the solution of the Navier-Stokes equations for flow near the leading edge of the plate and far away from the plate.How to match the solution of the SNS equations to the Blasius solution of the boundary layer equationsis also discussed.展开更多
The dynamical prediction of the Asian-Australian monsoon(AAM)has been an important and long-standing issue in climate science.In this study,the predictability of the first two leading modes of the AAM is studied using...The dynamical prediction of the Asian-Australian monsoon(AAM)has been an important and long-standing issue in climate science.In this study,the predictability of the first two leading modes of the AAM is studied using retrospective prediction datasets from the seasonal forecasting models in four operational centers worldwide.Results show that the model predictability of the leading AAM modes is sensitive to how they are defined in different seasonal sequences,especially for the second mode.The first AAM mode,from various seasonal sequences,coincides with the El Niño phase transition in the eastern-central Pacific.The second mode,initialized from boreal summer and autumn,leads El Niño by about one year but can exist during the decay phase of El Niño when initialized from boreal winter and spring.Our findings hint that ENSO,as an early signal,is conducive to better performance of model predictions in capturing the spatiotemporal variations of the leading AAM modes.Still,the persistence barrier of ENSO in spring leads to poor forecasting skills of spatial features.The multimodel ensemble(MME)mean shows some advantage in capturing the spatiotemporal variations of the AAM modes but does not provide a significant improvement in predicting its temporal features compared to the best individual models in predicting its temporal features.The BCC_CSM1.1M shows promising skill in predicting the two AAM indices associated with two leading AAM modes.The predictability demonstrated in this study is potentially useful for AAM prediction in operational and climate services.展开更多
This study focuses on a single-stage axial flow fan, investigating the effect of three kinds of wave leading edge stator blades on its noise reduction. The DDES method and the duct acoustic analogy theory based on the...This study focuses on a single-stage axial flow fan, investigating the effect of three kinds of wave leading edge stator blades on its noise reduction. The DDES method and the duct acoustic analogy theory based on the penetrable data surface were used for noise prediction. The results showed that the three kinds of wave leading edge blades were effective in reducing the rotor-stator interaction tonal noise and also have a certain inhibitory effect on broadband noise. The A10W15 stator blade can effectively reduce broadband noise in the frequency range of 2200 - 4200 Hz. When the amplitude is increased to 20, the noise reduction effect is further enhanced. However, when the amplitude is increased to 30, the broadband noise reduction effect is no longer significant. Further research shows that the wave leading edge stator blades can significantly change the pressure fluctuation distribution on the leading edge and suction surface, which control the modal energy distribution. Finally, this paper analyzed multiple factors affecting the broadband noise reduction, such as the noise source cut-off and cut-on effect and correlation. The purpose of this paper is to explore the laws of the influence of wave leading edge blades on the duct noise of real fan, and to reveal its noise control mechanism. .展开更多
Starting from one of the microscopic sdg interacting boson approximations, the lead-ing terms in the interaction Hamiltonian are discussed by using numerical investigations. Com-parisons of both the calculated levels ...Starting from one of the microscopic sdg interacting boson approximations, the lead-ing terms in the interaction Hamiltonian are discussed by using numerical investigations. Com-parisons of both the calculated levels and the overlap of wave functions between the exact re-sults and the approximations are made to find out negligible part in the Hamiltonian. The re-sults show that the leading terms given in this paper may provide a way to simplify the complexcalculations.展开更多
Economic responsibility audit is an important part of the socialist audit supervision system with Chinese characteristics.It is an important responsibility of audit institutions at all levels to carry out economic res...Economic responsibility audit is an important part of the socialist audit supervision system with Chinese characteristics.It is an important responsibility of audit institutions at all levels to carry out economic responsibility audit.This article conducts a comprehensive and profound analysis of the problems existing in the current grassroots economic responsibility audit work.In addition,countermeasures and suggestions are proposed in this article,which are of positive significance to promote the economic responsibility audit work of leading cadres.展开更多
With the implementation of a series of policies to support rural development,such as the national rural revitalization strategy and poverty alleviation,the economic responsibility audit of township party and governmen...With the implementation of a series of policies to support rural development,such as the national rural revitalization strategy and poverty alleviation,the economic responsibility audit of township party and government leading cadres has been given new responsibilities and missions.However,some grass-roots audit institutions are faced with practical difficulties such as the solidification of audit thinking,slow progress of audit informatization construction,and large gap of grass-roots audit resources.The only way to overcome the difficulties is to explore the transfonnation of the economic responsibility audit and countermeasures of the township party and government leading cadres by tracing the source and adapting measxires according to the difficulties.展开更多
Purpose/Significance: This study aims to define the concept of leading cadres new media usage in China specifically, and to describe and analyze the forms and typical cases and characteristics of leading cadres new me...Purpose/Significance: This study aims to define the concept of leading cadres new media usage in China specifically, and to describe and analyze the forms and typical cases and characteristics of leading cadres new media in different stages. Method/Process: Based on the themes and contents of a few media accounts of leading cadres at different ranks, we summarizes leading cadres new media usage in a systematic perspective and content analysize method. Result/Conclusion: The study defines the concept of Leading Cadres’ new media from the perspective of media practice, determine its position as a media communication platform in the government affairs new media communication system and its relationship with the other elements, and then systematically review the evolution of its media practice from personal website, blog, microblog and microblog to WeChat, live show. On this basis, with the Harold Lasswell communication model, this article summarizes leading cadres new media communication characteristics from five aspects: content producer, content, channel, audience, and effect. Future studies may also enhance the empirical research from the effect perspective.展开更多
This paper proposes a numerical method to analyze the ice protection capability and predict the power requirements of a piezoelectric resonant de-icing system.The method is based on a coupled electro-mechanical finite...This paper proposes a numerical method to analyze the ice protection capability and predict the power requirements of a piezoelectric resonant de-icing system.The method is based on a coupled electro-mechanical finite element analysis which enables the fast computation of the modes of resonance of interest to de-ice curved surfaces and the estimation of the input voltage and current required for a given configuration(defined by its mode,actuator location,ice deposit,etc.).Eventually,the electric power to be supplied can be also assessed.The method is applied to a NACA 0024 leading edge equipped with piezoelectric actuators.First,two extension modes are analyzed and compared with respect to their efficiency and power requirements.Then,tests are carried out in an icing tunnel to verify the effectiveness of the piezoelectric ice protection system and the predictions of the maximal required power.The system allows de-icing the leading edge in less than 2 s for a glaze ice deposit.展开更多
Lead iodide(PbI2) is a vital raw material for preparing perovskite solar cells(PSCs),and it not only takes part in forming the light absorption layer but also remains in the grain boundary as a passivator.In other wor...Lead iodide(PbI2) is a vital raw material for preparing perovskite solar cells(PSCs),and it not only takes part in forming the light absorption layer but also remains in the grain boundary as a passivator.In other words,the PbI2 content in the precursor and as formed film will affect the efficiency and stability of the PSCs.With moderate residual PbI2,it passivates the bulk/surface defects of perovskite,reduces the interfacial recombination,promotes the perovskite stability,minimizes the device hysteresis,and so on.Deficient PbI2 residue will reduce the interfacial passivation effect and device performance.In addition to facilitating the non-radiative recombination,over PbI2 residue can also lead to electronic insulation in the grain boundary and deteriorate the device performance.However,the impact and regulation of PbI2 residue on the device performance and stability is still not fully understood.Herein,a comprehensive and detailed review is presented by discussing the PbI2 residue impact and its regulation strategies(i.e., elimination,facilitation and conversion of the residue PbI2) to manipulate the PbI2 content,distribution and forms.Finally,we also show future outlooks in this field,with an aim to help further the progression of high-efficiency and stable PSCs.展开更多
Perovskite solar cells(PSCs)emerge as the most promising photovoltaics(PV)for their high performance and potential convenient cost-effective production routes comparing to the sophomore PV technologies.The printed PSC...Perovskite solar cells(PSCs)emerge as the most promising photovoltaics(PV)for their high performance and potential convenient cost-effective production routes comparing to the sophomore PV technologies.The printed PSCs with simplified device architecture and fabrication procedures could further enhance the competitive strength of PSC technology.In this work,we present an in-situ defect passivation(ISDP)assisted full-printing of high performance formamidine-lead bromide(FAPbBr_(3))PSCs.Only three rapid printing steps are involved for electron transporting layer(ETL),perovskite and carbon to form a complete solar cell on the low-cost fluorine-doped tin oxide(FTO)substrate.Long-chain polymer monomethyl ether polyethylene glycol is particularly utilized as the ISDP passivator,leading to conformal coating on the rough FTO and defect passivation for both ETL and perovskite during printing.A high efficiency of 10.85%(certified 10.14%)and a high V_(oc)up to 1.57 V are achieved for the printed device.The unencapsulated PSCs maintain above 90%of the initial efficiency after continuously heating at 85℃for 1000 h and over 80%of the efficiency after the maximum power point tracking for 3500 h.The fully printed semitransparent PSCs with carbon grids(CGs)show average visible light transmittance over 33%and an efficiency of 8.81%.展开更多
Two selenium(Se)-containing peptides from Se-enriched rice,TSeMMM and SeMDPGQQ,possess neuroprotective potency against lead(Pb2+)-induced cytotoxicity.However,the crosstalk between mRNA and microRNAs(miRNA)involved in...Two selenium(Se)-containing peptides from Se-enriched rice,TSeMMM and SeMDPGQQ,possess neuroprotective potency against lead(Pb2+)-induced cytotoxicity.However,the crosstalk between mRNA and microRNAs(miRNA)involved in the neuroprotection mechanism remains to be elucidated.In this study,RNA-sequencing and miRNA-sequencing were used to independently identify differentially expressed mRNAs and small RNAs profiles in Pb^(2+)-treated primary fetal rat cortical neurons and then the correlated miRNA-mRNA target pairs were obtained.It was found that 34 mRNAs related to oxidative phosphorylation could be reversed by pretreatment of TSeMMM and SeMDPGQQ.The protective effect of TSeMMM and SeMDPGQQ was mediated by upregulation of miR-107-3p,which downregulates the ATPase H+transporting V0 subunit e1(Atp6v0e1)mRNA level.A zebrafish model was applied to verify the relevance between the targeted mRNA and miRNA by real-time quantitative PCR.The results indicated that miR-107-3p was a potential therapeutic target to achieve neuroprotection of Se-containing peptides via stimulation of Atp6v0e1.展开更多
Perovskite solar cell has gained widespread attention as a promising technology for renewable energy.However, their commercial viability has been hampered by their long-term stability and potential Pb leakage. Herein,...Perovskite solar cell has gained widespread attention as a promising technology for renewable energy.However, their commercial viability has been hampered by their long-term stability and potential Pb leakage. Herein, we demonstrate a bifunctional passivator of the potassium tartrate(PT) to address both challenges. PT minimizes the Pb leakage in perovskites and also heals cationic vacancy defects, resulting in improved device performance and stability. Benefiting from PT modification, the power conversion efficiency(PCE) is improved to 23.26% and the Pb leakage in unencapsulated films is significantly reduced to 9.79 ppm. Furthermore, the corresponding device exhibits no significant decay in PCE after tracking at the maximum power point(MPP) for 2000 h under illumination(LED source, 100 mW cm^(-2)).展开更多
Epicatechin(EC)was used in this study to antagonize the cognitive dysfunction caused by lead(Pb)exposure in mice.Eight-week-old male Kunming mice were treated with PbCl_(2)(20 mg/kg)and/or EC(50 mg/kg)by gavage admini...Epicatechin(EC)was used in this study to antagonize the cognitive dysfunction caused by lead(Pb)exposure in mice.Eight-week-old male Kunming mice were treated with PbCl_(2)(20 mg/kg)and/or EC(50 mg/kg)by gavage administration for 4 weeks.Morris water maze test showed that EC could improve memory dysfunction induced by Pb.EC antagonized Ca^(2+)overload,activated Nrf2 signaling pathway and reduced the accumulation of Pb in the brain and serum,which suggested that EC might alter Pb distribution in mice.In vitro,spectroscopic analysis,potentiometric titration and docking studies were applied to inquiry into the interaction between bovine serum albumin(BSA)and Pb^(2+)in presence or absence of EC.EC was proved to chelate Pb^(2+)and reduced the interaction between BSA and Pb^(2+).In summary,EC might protect Pb-induced cognitive impairment by activating Nrf2 signaling pathway,and suppressing Pb accumulation via interference on the binding of Pb to albumin.展开更多
Forecasting uncertainties among meteorological fields have long been recognized as the main limitation on the accuracy and predictability of air quality forecasts.However,the particular impact of meteorological foreca...Forecasting uncertainties among meteorological fields have long been recognized as the main limitation on the accuracy and predictability of air quality forecasts.However,the particular impact of meteorological forecasting uncertainties on air quality forecasts specific to different seasons is still not well known.In this study,a series of forecasts with different forecast lead times for January,April,July,and October of 2018 are conducted over the Beijing-Tianjin-Hebei(BTH)region and the impacts of meteorological forecasting uncertainties on surface PM_(2.5)concentration forecasts with each lead time are investigated.With increased lead time,the forecasted PM_(2.5)concentrations significantly change and demonstrate obvious seasonal variations.In general,the forecasting uncertainties in monthly mean surface PM_(2.5)concentrations in the BTH region due to lead time are the largest(80%)in spring,followed by autumn(~50%),summer(~40%),and winter(20%).In winter,the forecasting uncertainties in total surface PM_(2.5)mass due to lead time are mainly due to the uncertainties in PBL heights and hence the PBL mixing of anthropogenic primary particles.In spring,the forecasting uncertainties are mainly from the impacts of lead time on lower-tropospheric northwesterly winds,thereby further enhancing the condensation production of anthropogenic secondary particles by the long-range transport of natural dust.In summer,the forecasting uncertainties result mainly from the decrease in dry and wet deposition rates,which are associated with the reduction of near-surface wind speed and precipitation rate.In autumn,the forecasting uncertainties arise mainly from the change in the transport of remote natural dust and anthropogenic particles,which is associated with changes in the large-scale circulation.展开更多
The neutron-induced total cross sections of natural lead have been measured in a wide energy range(0.3 eV-20 MeV)on the back-streaming white neutron beamline(Back-n)at the China Spallation Neutron Source.Neutron energ...The neutron-induced total cross sections of natural lead have been measured in a wide energy range(0.3 eV-20 MeV)on the back-streaming white neutron beamline(Back-n)at the China Spallation Neutron Source.Neutron energy was determined by the neutron total cross-section spectrometer using the time-of-flight technique.A fast multi-cell fission chamber was used as the neutron detector,and a 10-mm-thick high-purity natural lead sample was employed for the neutron transmission measurements.The on-beam background was determined using Co,In,Ag,and Cd filters.The excitation function of ^(nat)Pb(n,tot)reaction below 20 MeV was calculated using the TALYS-1.96 nuclear-reaction modeling program.The present results were compared with previous results,the evaluated data available in the five major evaluated nuclear data libraries(i.e.,ENDF/B-VIII.0,JEFF-3.3,JENDL-5,CENDL-3.2,and BROND-3.1),and the theoretical calculation curve.Good agreement was found between the new results and those of previous experiments and with the theoretical curves in the corresponding region.This measurement obtained the neutron total cross section of natural lead with good accuracy over a wide energy range and added experimental data in the resonance energy range.This provides more reliable experimental data for nuclear engineering design and nuclear data evaluation of lead.展开更多
基金Supported by Party Building Research Project of Hubei University of Science and Technology(2022DJ-11).
文摘In accordance with the pattern of"great ideology and politics",the Party and youth League organizations assume the role of vanguard in the organization of colleges and universities.Simultaneously,they serve as a pivotal force in ideological and political education.In order to construct a comprehensive ideological and political framework encompassing the entire educational process,it is of paramount importance to identify an efficacious methodology for Party building leading League construction.This paper employs a comprehensive analysis to elucidate the pivotal role of Party building leading League construction in facilitating ideological and political education.It also illuminates the practical challenges encountered in the implementation of Party building leading League construction initiatives within colleges and universities.The article proposes a specific path for Party building leading League construction in colleges and universities based on three key aspects:cohesion of the consensus of Party building leading League building,establishment of the institutional system of Party building leading League construction,and creation of the model brand of Party building leading League construction.The aim is to promote in-depth development of Party building in colleges and universities and enhance the quality and effect of ideological and political education.
基金Natural Science Foundation of Liaoning Province(2022-MS-305)Foundation of Liaoning Province Education Administration(LJKZ1108).
文摘The effects of the erosion present on the leading edge of a wind turbine airfoil(DU 96-W-180)on its aerodynamic performances have been investigated numerically in the framework of a SST k–ωturbulence model based on the Reynolds Averaged Navier-Stokes equations(RANS).The results indicate that when sand-induced holes and small pits are involved as leading edge wear features,they have a minimal influence on the lift and drag coefficients of the airfoil.However,if delamination occurs in the same airfoil region,it significantly impacts the lift and resistance characteristics of the airfoil.Specifically,as the angle of attack grows,there is a significant decrease in the lift coefficient accompanied by a sharp increase in the drag coefficient.As wear intensifies,these effects gradually increase.Moreover,the leading edge wear can exacerbate flow separation near the trailing edge suction surface of the airfoil and cause forward displacement of the separation point.
基金supported by the National Natural Science Foundation of China(22072034,and 22001050)the China Postdoctoral Science Foundation(2022M710949,2020T130147,and 2020M681084)+2 种基金the Postdoctoral Foundation of Heilongjiang Province(LBH-Z22106,and LBH-Z19059)the Natural Science Foundation of Heilongjiang Youth Fund(YQ2021B002)Education Department of Heilongjiang Province(LJYXL2022-038).
文摘Although covalent organic frameworks(COFs)with highπ-conjugation have recently exhibited great prospects in perovskite solar cells(PSCs),their further application in PSCs is still hindered by face-to-face stacking and aggregation issues.Herein,metal-organic framework(MOF-808)is selected as an ideal platform for the in situ homogeneous growth of a COF to construct a core-shell MOF@COF nanoparticle,which could effectively inhibit COF stacking and aggregation.The synergistic intrinsic mechanisms induced by the MOF@COF nanoparticles for reinforcing intrinsic stability and mitigating lead leakage in PSCs have been explored.The complementary utilization ofπ-conjugated skeletons and nanopores could optimize the crystallization of large-grained perovskite films and eliminate defects.The resulting PSCs achieve an impressive power conversion efficiency of 23.61%with superior open circuit voltage(1.20 V)and maintained approximately 90%of the original power conversion efficiency after 2000 h(30-50%RH and 25-30℃).Benefiting from the synergistic effects of the in situ chemical fixation and adsorption abilities of the MOF@COF nanoparticles,the amount of lead leakage from unpackaged PSCs soaked in water(<5 ppm)satisfies the laboratory assessment required for the Resource Conservation and Recovery Act Regulation.
基金National Natural Science Foundation of China(42230603,42275020)Guangdong Major Project of Basic and Applied Basic Research(2020B0301030004)+3 种基金Guangdong Province Key Laboratory for Climate Change and Natural Disaster Studies(2020B1212060025)Innovation Group Project of Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai)(311021001)Open Fund of State Key Laboratory of Satellite Ocean Environment Dynamics,Second Institute of Oceanography,MNR(QNHX2310)Future Earth Early-Career Fellowship of the Future Earth Global Secretariat Hub China。
文摘Drought events have become more frequent and intense over East Asia in recent decades,leading to huge socioeconomic impacts.Although the droughts have been studied extensively by cases or for individual regions,their leading variability and associated causes remain unclear.Based on the Standardized Precipitation Evapotranspiration Index(SPEI)and ERA5 reanalysis product from 1979 to 2020,this study evealuates the severity of spring droughts in East Asia and investigates their variations and associated drivers.The results indicate that North China and Mongolia have experienced remarkable trends toward dryness during spring in recent decades,while southwestern China has witnessed an opposite trend toward wetness.The first Empirical Orthogonal Function mode of SPEI variability reveals a similar seesawing pattern,with more severe dryness in northwestern China,Mongolia,North China,South Korea,and Japan but increased wetness in Southwestern China and southeast Asia.Further investigation reveals that the anomalously dry(wet)surface in North(Southwestern)China is significantly associated with anomalously high(low)temperature,less(more)precipitation,and reduced(increased)soil moisture during the previous winter and early spring,regulated by an anomalous anticyclone(cyclone)and thus reduced(increased)water vapor convergence.The spring dry-wet pattern in East Asia is also linked to cold sea surface temperature anomalies in the central-eastern Pacific.The findings of this study have important implications for improving the prediction of spring drought events in East Asia.
文摘Both, the dilemma to find a quantum field theory consistent with Einstein’s law of relativity and the problem to describe existing particles as bound states of matter has been solved by calculating bound state matrix elements from a dual fermion-boson Lagrangian. In this formalism, the fermion binding energies are compensated by boson energies, indicating that particles can be generated out of the vacuum. This yields quantitative solutions for various mesons ω (0.78 GeV) - Υ (9.46 GeV) and all leptons e, μ and τ, with uncertainties in the extracted properties of less than 1‰. For transparency, a Web-page with the address htpps://h2909473.stratoserver.net has been constructed, where all calculations can be run on line and also the underlying fortran source code can be inspected.
文摘Starting from the Simplified Navier-Stokes(SNS)equations presented at first by Godovachev-Kuzmin-Tsopov,and Gao Zhi,Davis,the authors analyze the character of the SNS equations for the laminarflow near the leading edge of a flat plate and far away from the plate by using the Weiner—Hopf meth-od and Fourier transform.It is proved that the solution of the SNS equations agree with the solution of the Navier-Stokes equations for flow near the leading edge of the plate and far away from the plate.How to match the solution of the SNS equations to the Blasius solution of the boundary layer equationsis also discussed.
基金supported by the National Natural Science Foundation of China(Grant Nos.U2242206,41975094 and 41905062)the National Key Research and Development Program on monitoring,Early Warning and Prevention of Major Natural Disaster(Grant Nos.2017YFC1502302 and 2018YFC1506005)+1 种基金the Basic Research and Operational Special Project of CAMS(Grant No.2021Z007)the Met Office Climate Science for Service Partnership(CSSP)China.
文摘The dynamical prediction of the Asian-Australian monsoon(AAM)has been an important and long-standing issue in climate science.In this study,the predictability of the first two leading modes of the AAM is studied using retrospective prediction datasets from the seasonal forecasting models in four operational centers worldwide.Results show that the model predictability of the leading AAM modes is sensitive to how they are defined in different seasonal sequences,especially for the second mode.The first AAM mode,from various seasonal sequences,coincides with the El Niño phase transition in the eastern-central Pacific.The second mode,initialized from boreal summer and autumn,leads El Niño by about one year but can exist during the decay phase of El Niño when initialized from boreal winter and spring.Our findings hint that ENSO,as an early signal,is conducive to better performance of model predictions in capturing the spatiotemporal variations of the leading AAM modes.Still,the persistence barrier of ENSO in spring leads to poor forecasting skills of spatial features.The multimodel ensemble(MME)mean shows some advantage in capturing the spatiotemporal variations of the AAM modes but does not provide a significant improvement in predicting its temporal features compared to the best individual models in predicting its temporal features.The BCC_CSM1.1M shows promising skill in predicting the two AAM indices associated with two leading AAM modes.The predictability demonstrated in this study is potentially useful for AAM prediction in operational and climate services.
文摘This study focuses on a single-stage axial flow fan, investigating the effect of three kinds of wave leading edge stator blades on its noise reduction. The DDES method and the duct acoustic analogy theory based on the penetrable data surface were used for noise prediction. The results showed that the three kinds of wave leading edge blades were effective in reducing the rotor-stator interaction tonal noise and also have a certain inhibitory effect on broadband noise. The A10W15 stator blade can effectively reduce broadband noise in the frequency range of 2200 - 4200 Hz. When the amplitude is increased to 20, the noise reduction effect is further enhanced. However, when the amplitude is increased to 30, the broadband noise reduction effect is no longer significant. Further research shows that the wave leading edge stator blades can significantly change the pressure fluctuation distribution on the leading edge and suction surface, which control the modal energy distribution. Finally, this paper analyzed multiple factors affecting the broadband noise reduction, such as the noise source cut-off and cut-on effect and correlation. The purpose of this paper is to explore the laws of the influence of wave leading edge blades on the duct noise of real fan, and to reveal its noise control mechanism. .
基金The project supported by the National Natural Science Foundation of China
文摘Starting from one of the microscopic sdg interacting boson approximations, the lead-ing terms in the interaction Hamiltonian are discussed by using numerical investigations. Com-parisons of both the calculated levels and the overlap of wave functions between the exact re-sults and the approximations are made to find out negligible part in the Hamiltonian. The re-sults show that the leading terms given in this paper may provide a way to simplify the complexcalculations.
文摘Economic responsibility audit is an important part of the socialist audit supervision system with Chinese characteristics.It is an important responsibility of audit institutions at all levels to carry out economic responsibility audit.This article conducts a comprehensive and profound analysis of the problems existing in the current grassroots economic responsibility audit work.In addition,countermeasures and suggestions are proposed in this article,which are of positive significance to promote the economic responsibility audit work of leading cadres.
文摘With the implementation of a series of policies to support rural development,such as the national rural revitalization strategy and poverty alleviation,the economic responsibility audit of township party and government leading cadres has been given new responsibilities and missions.However,some grass-roots audit institutions are faced with practical difficulties such as the solidification of audit thinking,slow progress of audit informatization construction,and large gap of grass-roots audit resources.The only way to overcome the difficulties is to explore the transfonnation of the economic responsibility audit and countermeasures of the township party and government leading cadres by tracing the source and adapting measxires according to the difficulties.
文摘Purpose/Significance: This study aims to define the concept of leading cadres new media usage in China specifically, and to describe and analyze the forms and typical cases and characteristics of leading cadres new media in different stages. Method/Process: Based on the themes and contents of a few media accounts of leading cadres at different ranks, we summarizes leading cadres new media usage in a systematic perspective and content analysize method. Result/Conclusion: The study defines the concept of Leading Cadres’ new media from the perspective of media practice, determine its position as a media communication platform in the government affairs new media communication system and its relationship with the other elements, and then systematically review the evolution of its media practice from personal website, blog, microblog and microblog to WeChat, live show. On this basis, with the Harold Lasswell communication model, this article summarizes leading cadres new media communication characteristics from five aspects: content producer, content, channel, audience, and effect. Future studies may also enhance the empirical research from the effect perspective.
文摘This paper proposes a numerical method to analyze the ice protection capability and predict the power requirements of a piezoelectric resonant de-icing system.The method is based on a coupled electro-mechanical finite element analysis which enables the fast computation of the modes of resonance of interest to de-ice curved surfaces and the estimation of the input voltage and current required for a given configuration(defined by its mode,actuator location,ice deposit,etc.).Eventually,the electric power to be supplied can be also assessed.The method is applied to a NACA 0024 leading edge equipped with piezoelectric actuators.First,two extension modes are analyzed and compared with respect to their efficiency and power requirements.Then,tests are carried out in an icing tunnel to verify the effectiveness of the piezoelectric ice protection system and the predictions of the maximal required power.The system allows de-icing the leading edge in less than 2 s for a glaze ice deposit.
基金financially supported by the National Natural Science Foundation of China(U21A2078,22179042,and 12104170)the Natural Science Foundation of Fujian Province(2020J06021 and 2020J01064)Scientific Research Funds of Huaqiao University(23BS109)。
文摘Lead iodide(PbI2) is a vital raw material for preparing perovskite solar cells(PSCs),and it not only takes part in forming the light absorption layer but also remains in the grain boundary as a passivator.In other words,the PbI2 content in the precursor and as formed film will affect the efficiency and stability of the PSCs.With moderate residual PbI2,it passivates the bulk/surface defects of perovskite,reduces the interfacial recombination,promotes the perovskite stability,minimizes the device hysteresis,and so on.Deficient PbI2 residue will reduce the interfacial passivation effect and device performance.In addition to facilitating the non-radiative recombination,over PbI2 residue can also lead to electronic insulation in the grain boundary and deteriorate the device performance.However,the impact and regulation of PbI2 residue on the device performance and stability is still not fully understood.Herein,a comprehensive and detailed review is presented by discussing the PbI2 residue impact and its regulation strategies(i.e., elimination,facilitation and conversion of the residue PbI2) to manipulate the PbI2 content,distribution and forms.Finally,we also show future outlooks in this field,with an aim to help further the progression of high-efficiency and stable PSCs.
基金supported by the Guangdong Pearl River Talent Program(2021ZT09L400)National Natural Science Foundation of China(52072284,21875178,91963209)the Joint Funds of Natural Science Foundation of Hubei Province(2022CFD087).
文摘Perovskite solar cells(PSCs)emerge as the most promising photovoltaics(PV)for their high performance and potential convenient cost-effective production routes comparing to the sophomore PV technologies.The printed PSCs with simplified device architecture and fabrication procedures could further enhance the competitive strength of PSC technology.In this work,we present an in-situ defect passivation(ISDP)assisted full-printing of high performance formamidine-lead bromide(FAPbBr_(3))PSCs.Only three rapid printing steps are involved for electron transporting layer(ETL),perovskite and carbon to form a complete solar cell on the low-cost fluorine-doped tin oxide(FTO)substrate.Long-chain polymer monomethyl ether polyethylene glycol is particularly utilized as the ISDP passivator,leading to conformal coating on the rough FTO and defect passivation for both ETL and perovskite during printing.A high efficiency of 10.85%(certified 10.14%)and a high V_(oc)up to 1.57 V are achieved for the printed device.The unencapsulated PSCs maintain above 90%of the initial efficiency after continuously heating at 85℃for 1000 h and over 80%of the efficiency after the maximum power point tracking for 3500 h.The fully printed semitransparent PSCs with carbon grids(CGs)show average visible light transmittance over 33%and an efficiency of 8.81%.
基金supported by the National Natural Science Foundation of China(32272319,31972020,32202032)the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD).
文摘Two selenium(Se)-containing peptides from Se-enriched rice,TSeMMM and SeMDPGQQ,possess neuroprotective potency against lead(Pb2+)-induced cytotoxicity.However,the crosstalk between mRNA and microRNAs(miRNA)involved in the neuroprotection mechanism remains to be elucidated.In this study,RNA-sequencing and miRNA-sequencing were used to independently identify differentially expressed mRNAs and small RNAs profiles in Pb^(2+)-treated primary fetal rat cortical neurons and then the correlated miRNA-mRNA target pairs were obtained.It was found that 34 mRNAs related to oxidative phosphorylation could be reversed by pretreatment of TSeMMM and SeMDPGQQ.The protective effect of TSeMMM and SeMDPGQQ was mediated by upregulation of miR-107-3p,which downregulates the ATPase H+transporting V0 subunit e1(Atp6v0e1)mRNA level.A zebrafish model was applied to verify the relevance between the targeted mRNA and miRNA by real-time quantitative PCR.The results indicated that miR-107-3p was a potential therapeutic target to achieve neuroprotection of Se-containing peptides via stimulation of Atp6v0e1.
基金funding support from the National Natural Science Foundation of China (52172182, 21975028, 22011540377, 22005035, U21A20172)。
文摘Perovskite solar cell has gained widespread attention as a promising technology for renewable energy.However, their commercial viability has been hampered by their long-term stability and potential Pb leakage. Herein, we demonstrate a bifunctional passivator of the potassium tartrate(PT) to address both challenges. PT minimizes the Pb leakage in perovskites and also heals cationic vacancy defects, resulting in improved device performance and stability. Benefiting from PT modification, the power conversion efficiency(PCE) is improved to 23.26% and the Pb leakage in unencapsulated films is significantly reduced to 9.79 ppm. Furthermore, the corresponding device exhibits no significant decay in PCE after tracking at the maximum power point(MPP) for 2000 h under illumination(LED source, 100 mW cm^(-2)).
基金supported by the National Key Research and Development Program of China under Grant(2022YFF1102800)the Graduate Scientific Research Innovation Project of Tianji(2022SKY109)+1 种基金the Project of Tianjin Science and Technology Program(22JCYBJC00360)the Project of Tianjin Science and Technology Program(21ZYJDJC00060)。
文摘Epicatechin(EC)was used in this study to antagonize the cognitive dysfunction caused by lead(Pb)exposure in mice.Eight-week-old male Kunming mice were treated with PbCl_(2)(20 mg/kg)and/or EC(50 mg/kg)by gavage administration for 4 weeks.Morris water maze test showed that EC could improve memory dysfunction induced by Pb.EC antagonized Ca^(2+)overload,activated Nrf2 signaling pathway and reduced the accumulation of Pb in the brain and serum,which suggested that EC might alter Pb distribution in mice.In vitro,spectroscopic analysis,potentiometric titration and docking studies were applied to inquiry into the interaction between bovine serum albumin(BSA)and Pb^(2+)in presence or absence of EC.EC was proved to chelate Pb^(2+)and reduced the interaction between BSA and Pb^(2+).In summary,EC might protect Pb-induced cognitive impairment by activating Nrf2 signaling pathway,and suppressing Pb accumulation via interference on the binding of Pb to albumin.
基金supported by the National Key Research and Development Program of China(No.2022YFC3700701)National Natural Science Foundation of China(Grant Nos.41775146,42061134009)+1 种基金USTC Research Funds of the Double First-Class Initiative(YD2080002007)Strategic Priority Research Program of Chinese Academy of Sciences(XDB41000000).
文摘Forecasting uncertainties among meteorological fields have long been recognized as the main limitation on the accuracy and predictability of air quality forecasts.However,the particular impact of meteorological forecasting uncertainties on air quality forecasts specific to different seasons is still not well known.In this study,a series of forecasts with different forecast lead times for January,April,July,and October of 2018 are conducted over the Beijing-Tianjin-Hebei(BTH)region and the impacts of meteorological forecasting uncertainties on surface PM_(2.5)concentration forecasts with each lead time are investigated.With increased lead time,the forecasted PM_(2.5)concentrations significantly change and demonstrate obvious seasonal variations.In general,the forecasting uncertainties in monthly mean surface PM_(2.5)concentrations in the BTH region due to lead time are the largest(80%)in spring,followed by autumn(~50%),summer(~40%),and winter(20%).In winter,the forecasting uncertainties in total surface PM_(2.5)mass due to lead time are mainly due to the uncertainties in PBL heights and hence the PBL mixing of anthropogenic primary particles.In spring,the forecasting uncertainties are mainly from the impacts of lead time on lower-tropospheric northwesterly winds,thereby further enhancing the condensation production of anthropogenic secondary particles by the long-range transport of natural dust.In summer,the forecasting uncertainties result mainly from the decrease in dry and wet deposition rates,which are associated with the reduction of near-surface wind speed and precipitation rate.In autumn,the forecasting uncertainties arise mainly from the change in the transport of remote natural dust and anthropogenic particles,which is associated with changes in the large-scale circulation.
基金This work is supported by the National Natural Science Foundation of China(No.12375296)the Key Laboratory of Nuclear Data Foundation(No.JCKY2022201C153)+2 种基金the Natural Science Foundation of Hunan Province of China(Nos.2021JJ40444,2020RC3054)the Youth Innovation Promotion Association CAS(No.2023014)the National Key Research and Development Plan(No.2022YFA1603303).
文摘The neutron-induced total cross sections of natural lead have been measured in a wide energy range(0.3 eV-20 MeV)on the back-streaming white neutron beamline(Back-n)at the China Spallation Neutron Source.Neutron energy was determined by the neutron total cross-section spectrometer using the time-of-flight technique.A fast multi-cell fission chamber was used as the neutron detector,and a 10-mm-thick high-purity natural lead sample was employed for the neutron transmission measurements.The on-beam background was determined using Co,In,Ag,and Cd filters.The excitation function of ^(nat)Pb(n,tot)reaction below 20 MeV was calculated using the TALYS-1.96 nuclear-reaction modeling program.The present results were compared with previous results,the evaluated data available in the five major evaluated nuclear data libraries(i.e.,ENDF/B-VIII.0,JEFF-3.3,JENDL-5,CENDL-3.2,and BROND-3.1),and the theoretical calculation curve.Good agreement was found between the new results and those of previous experiments and with the theoretical curves in the corresponding region.This measurement obtained the neutron total cross section of natural lead with good accuracy over a wide energy range and added experimental data in the resonance energy range.This provides more reliable experimental data for nuclear engineering design and nuclear data evaluation of lead.