Monkeypox was declared a global health emergency by the World Health Organization,and as of March 2023,86,000 confirmed cases and 111 deaths across 110 countries have been reported.Its causal agent,monkeypox virus(MPV...Monkeypox was declared a global health emergency by the World Health Organization,and as of March 2023,86,000 confirmed cases and 111 deaths across 110 countries have been reported.Its causal agent,monkeypox virus(MPV)belongs to a large family of double-stranded DNA viruses,Orthopoxviridae,that also includes vaccinia virus(VACV)and others.MPV produces two distinct forms of viral particles during its replication cycles:the enveloped viron(EV)that is released via exocytosis,and the mature viron(MV)that is discharged through lysis of host cells.This study was designed to develop multi-valent m RNA vaccines against monkeypox EV and MV surface proteins,and examine their efficacy and mechanism of action.Four m RNA vaccines were produced with different combinations of surface proteins from EV(A35R and B6R),MV(A29L,E8L,H3L and M1R),or EV and MV,and were administered in Balb/c mice to assess their immunogenicity potentials.A dynamic immune response was observed as soon as seven days after initial immunization,while a strong Ig G response to all immunogens was detected with ELISA after two vaccinations.The higher number of immunogens contributed to a more robust total Ig G response and correlating neutralizing activity against VACV,indicating the additive potential of each immunogen in generating immune response and nullifying VACV infection.Further,the m RNA vaccines elicited an antigen-specific CD4^(+)T cell response that is biased towards Th1.The m RNA vaccines with different combinations of EVand MV surface antigens protected a mouse model from a lethal dose VACV challenge,with the EV and MV antigens-combined vaccine offering the strongest protection.These findings provide insight into the protective mechanism of multi-valent m RNAvaccines against MPV,and also the foundation for further development of effective and safe m RNA vaccines for enhanced protection against monkeypox virus outbreak.展开更多
This study reveals the critical role of multiscale interaction within the westerly wind bursts(WWBs)west of the MJO convection in modulating the prediction skill for the November MJO event during the DYNAMO(Dynamics o...This study reveals the critical role of multiscale interaction within the westerly wind bursts(WWBs)west of the MJO convection in modulating the prediction skill for the November MJO event during the DYNAMO(Dynamics of the Madden–Julian Oscillation)field campaign.The characteristics of the MJO convection envelope are obtained by the largescale precipitation tracking method,and a novel metric is introduced to quantify the prediction skill for the MJO convection in the ECMWF reforecast.The ECMWF forecast exhibits approximately 17 days in skillful prediction for the MJO convection—significantly lower than that derived from the global measure.The reforecast ensembles are further classified into high and low skill catalogs based on the mean prediction skill during the observed WWBs period.High-skill ensembles exhibit significantly enhanced low-level westerlies,amplified MJO convection,and reduced spatial separation between the low-level westerlies and MJO convection during the WWBs period,indicating stronger coupling between the large-scale circulation and the convection.Mechanistic analysis reveals that enhanced westerlies in high-skill ensembles can transfer more high-frequency energy to the MJO convection through the flux convergence of interaction energy for MJO convection development,resulting in better prediction skill.展开更多
The formation and evolution of binary stars are key steps in star formation and evolution,and thus their research has become the core content of modern astronomical research.Although as early as 1976,Bodan Pachenski p...The formation and evolution of binary stars are key steps in star formation and evolution,and thus their research has become the core content of modern astronomical research.Although as early as 1976,Bodan Pachenski proposed the theory of the evolution of shared envelopes in binary stars,but it was never confirmed until 2022 when the Yunnan Astronomical Observatory of the Chinese Academy of Sciences and an Australian team first observed the phenomenon of shared envelope ejection in binary stars,which provided support for Bodan Pachenski’s theory,but the true formation mechanism and evolution process of binary stars remain undetermined.For this reason,the author of this paper has proposed a theory of the formation and evolution of binary stars based on the theory of the evolution of common envelopes in binary stars and the theory of tidal disruption events,laying a foundation for establishing a complete theory of star formation and evolution.展开更多
Oil-fired construction machinery(OCM)is a major source of urban air pollutants and CO_(2) emissions,and elec-trification is a crucial pathway for improving air quality and achieving China’s dual carbon goals;however,...Oil-fired construction machinery(OCM)is a major source of urban air pollutants and CO_(2) emissions,and elec-trification is a crucial pathway for improving air quality and achieving China’s dual carbon goals;however,its feasibility has not been fully explored.This study uses data envelopment analysis and the analytic hierarchy process to establish a development potential index,covering technical efficiency,economic cost,application sce-narios,and charging time and range,with an empirical analysis conducted in Beijing.The findings indicated the high feasibility of replacing OCM with electric alternatives,especially within the low-power range.Based on 2023 registered coding dat1,it is projected that by 2030,electrification could reduce regional average con-centrations of CO,NO_(x),PM_(2.5) and VOCs by 12.2%to 56.4%and reduce CO_(2) by 11.7%to 56.9%.Owing to economic considerations,small-and medium-sized machinery are particularly feasible for electrification.Key recommendations include prioritizing the electrification of forklifts,lifting platforms,and small-sized machinery in high-emission areas,particularly in central urban districts.Policies such as carbon taxes,carbon markets,and performance grading systems are suggested to incentivize electrification,along with expanding high-emission restriction zones and improving energy infrastructure to support widespread electrification.展开更多
Curtain wall systems have evolved from aesthetic facade elements into multifunctional building envelopes that actively contribute to energy efficiency and climate responsiveness.This reviewpresents a comprehensive exa...Curtain wall systems have evolved from aesthetic facade elements into multifunctional building envelopes that actively contribute to energy efficiency and climate responsiveness.This reviewpresents a comprehensive examination of curtain walls from an energy-engineering perspective,highlighting their structural typologies(Stick and Unitized),material configurations,and integration with smart technologies such as electrochromic glazing,parametric design algorithms,and Building Management Systems(BMS).Thestudy explores the thermal,acoustic,and solar performance of curtain walls across various climatic zones,supported by comparative analyses and iconic case studies including Apple Park,Burj Khalifa,and Milad Tower.Key challenges—including installation complexity,high maintenance costs,and climate sensitivity—are critically assessed alongside proposed solutions.A central innovation of this work lies in framing curtain walls not only as passive architectural elements but as dynamic interfaces that modulate energy flows,reduce HVAC loads,and enhance occupant comfort.The reviewed data indicate that optimized curtain wall configurations—especially those integrating electrochromic glazing and BIPV modules—can achieve annual energy consumption reductions ranging fromapproximately 5%to 27%,depending on climate,control strategy,and facade typology.The findings offer a valuable reference for architects,energy engineers,and decision-makers seeking to integrate high-performance facades into future-ready building designs.展开更多
In this note,the authors revisit the envelope dimension reduction,which was first introduced for estimating a sufficient dimension reduction subspace without inverting the sample covariance.Motivated by the recent dev...In this note,the authors revisit the envelope dimension reduction,which was first introduced for estimating a sufficient dimension reduction subspace without inverting the sample covariance.Motivated by the recent developments in envelope methods and algorithms,the authors refresh the envelope inverse regression as a flexible alternative to the existing inverse regression methods in dimension reduction.The authors discuss the versatility of the envelope approach and demonstrate the advantages of the envelope dimension reduction through simulation studies.展开更多
Classical linear discriminant analysis(LDA)(Fisher,1936)implicitly assumes the classification boundary depends on only one linear combination of the predictors.This restriction can lead to poor classification in appli...Classical linear discriminant analysis(LDA)(Fisher,1936)implicitly assumes the classification boundary depends on only one linear combination of the predictors.This restriction can lead to poor classification in applications where the decision boundary depends on multiple linear combinations of the predictors.To overcome this challenge,the authors first project the predictors onto an envelope central space and then perform LDA based on the sufficient predictor.The performance of the proposed method in improving classification accuracy is demonstrated in both synthetic data and real applications.展开更多
The carbon emission trading policy is a key policy for China to achieve its dual carbon goals.This paper aims to examine the emission-reduction effects,transmission mechanisms,and carbon-market efficiency of China’s ...The carbon emission trading policy is a key policy for China to achieve its dual carbon goals.This paper aims to examine the emission-reduction effects,transmission mechanisms,and carbon-market efficiency of China’s carbon-emission trading policy from 2012 to 2023.We adopt the difference-in-differences(DID)model to analyze the effects of policy on emissions,and the empirical results from the DID model confirm that the pilot carbon emission trading policy has significantly reduced carbon emission intensity in pilot areas.Then we use the mediation model to study the transmission mechanism of the pilot carbon emission trading policy,and the mediation analysis demonstrates that the pilot carbon emission trading policy achieves emission abatement through four parallel transmission channels:scientific innovation,energy conservation,clean energy substitution,and industrial structure upgrading.Data envelopment analysis evaluates the carbon market efficiency of China.The result shows that the average carbon market efficiency of pilot areas has improved steadily,particularly from 2012 to 2023,especially in Beijing,Hubei,and Guangdong.Moreover,the efficiency of the national carbon market has shown an upward trend since its 2021 launch;it remains lower than the pilot average,constrained primarily by limited sectoral coverage,which impacts scale efficiency.展开更多
The goal of the present work is to demonstrate the potential of Artificial Neural Network(ANN)-driven Genetic Algorithm(GA)methods for energy efficiency and economic performance optimization of energy efficiency measu...The goal of the present work is to demonstrate the potential of Artificial Neural Network(ANN)-driven Genetic Algorithm(GA)methods for energy efficiency and economic performance optimization of energy efficiency measures in a multi-family house building in Greece.The energy efficiency measures include different heating/cooling systems(such as low-temperature and high-temperature heat pumps,natural gas boilers,split units),building envelope components for floor,walls,roof and windows of variable heat transfer coefficients,the installation of solar thermal collectors and PVs.The calculations of the building loads and investment and operating and maintenance costs of the measures are based on the methodology defined in Directive 2010/31/EU,while economic assumptions are based on EN 15459-1 standard.Typically,multi-objective optimization of energy efficiency measures often requires the simulation of very large numbers of cases involving numerous possible combinations,resulting in intense computational load.The results of the study indicate that ANN-driven GA methods can be used as an alternative,valuable tool for reliably predicting the optimal measures which minimize primary energy consumption and life cycle cost of the building with greatly reduced computational requirements.Through GA methods,the computational time needed for obtaining the optimal solutions is reduced by 96.4%-96.8%.展开更多
Enveloped viruses have been the leading causative agents of viral epidemics in the past decade,including the ongoing coronavirus disease 2019 outbreak.In epidemics caused by enveloped viruses,direct contact is a commo...Enveloped viruses have been the leading causative agents of viral epidemics in the past decade,including the ongoing coronavirus disease 2019 outbreak.In epidemics caused by enveloped viruses,direct contact is a common route of infection,while indirect transmissions through the environment also contribute to the spread of the disease,although their significance remains controversial.Bridging the knowledge gap regarding the influence of interfacial interactions on the persistence of enveloped viruses in the environment reveals the transmission mechanisms when the virus undergoes mutations and prevents excessive disinfection during viral epidemics.Herein,from the perspective of the driving force,partition efficiency,and viral survivability at interfaces,we summarize the viral and environmental characteristics that affect the environmental transmission of viruses.We expect to provide insights for virus detection,environmental surveillance,and disinfection to limit the spread of severe acute respiratory syndrome coronavirus 2.展开更多
Enveloped RNA viruses are a group of viruses with an outer membrane derived from a host cell and a genome consisting of ribonucleic acid(RNA).These viruses rely on host cell machinery and organelles to replicate and a...Enveloped RNA viruses are a group of viruses with an outer membrane derived from a host cell and a genome consisting of ribonucleic acid(RNA).These viruses rely on host cell machinery and organelles to replicate and assemble new virus particles.However,the interaction between viruses and host organelles may be disrupted by nanomaterials,such as gold nanoparticles(AuNPs)with unique physical and chemical properties.In this study,we investigated the effects of AuNPs with different surface charge properties on the subcellular structure and function of mammalian cells,and their effects on two representative enveloped RNA viruses:lentivirus and human coronavirus OC43(HCoV-OC43)antiviral potential.By comparing the subcellular effects of AuNPs with different surface charge properties,we found that treatment with AuNPs with positive surface charges induced more significant disruption of subcellular structures than neutrally charged AuNPs and negatively charged AuNPs,mainly manifested in lysosomes and Cytoskeletal disorders.The antiviral effect of the surface positively charged AuNPs was further evaluated using lentivirus and HCoV-OC43.The results showed that AuNPs had a significant inhibitory effect on both lentivirus and HCoV-OC43 without obvious side effects.In conclusion,our study provides insights into the mechanism of action and biocompatibility of AuNP in biological systems,while supporting the potential of targeting organelle dynamics against enveloped RNA viruses.展开更多
Bocapavovirus,a member of the genus Bocaparvovirus within the subfamily Parvovirinae and the family Parvoviridae,is a small,non-enveloped,single-stranded DNA virus.This pathogen poses health risks to both humans and a...Bocapavovirus,a member of the genus Bocaparvovirus within the subfamily Parvovirinae and the family Parvoviridae,is a small,non-enveloped,single-stranded DNA virus.This pathogen poses health risks to both humans and animals.The Bocaparvovirus genome.展开更多
Spiral bevel gears are critical transmission components,and are widely used in the aerospace field.This paper proposes a new multi-DOF envelope forming process for fabricating spiral bevel gears.Firstly,the multi-DOF ...Spiral bevel gears are critical transmission components,and are widely used in the aerospace field.This paper proposes a new multi-DOF envelope forming process for fabricating spiral bevel gears.Firstly,the multi-DOF envelope forming principle of spiral bevel gears is proposed.Secondly,the design methods for the envelope tool geometry and movement are proposed based on the envelope geometry and movement relationships.Thirdly,the metal flow and tooth filling laws are revealed through 3D FE simulation of the multi-DOF envelope forming process of a typical spiral bevel gear.Fourthly,a new method for separating the envelope tool and the formed spiral bevel gear with back taper tooth is proposed to avoid their interference.Finally,experiments on multi-DOF envelope forming of this typical spiral bevel gear are conducted using new heavy load multi-DOF envelope forming equipment.The simulation and experimental results show the feasibility of the proposed multi-DOF envelope forming process for fabricating spiral bevel gears with back taper tooth and the corresponding process design methods.展开更多
Ports are crucial to the economy of many nations;thus, numerous studies have been conducted on port efficiency and productivity. This study analyses the efficiency and productivity of some major global ports namely, P...Ports are crucial to the economy of many nations;thus, numerous studies have been conducted on port efficiency and productivity. This study analyses the efficiency and productivity of some major global ports namely, Port of Singapore, Rotterdam, Antwerp and Durban. The main objectives of this study are to determine the level of operational efficiency of the mentioned ports, measure and evaluate the ports’ productivity changes and lastly to investigate the factors influencing the productivity changes of the ports studied. To achieve these objectives, Data Envelopment Analysis (DEA-BCC) model was used to determine the technical and operational efficiencies of the ports and Malmquist productivity index was employed to calculate the various productivity levels. The results of the study can guide stakeholders to formulate their operational strategies for port efficiency and productivity. The study also has policy suggestions that are uniquely targeted to Africa’s issues and potential.展开更多
Studies on coral aggregate concrete(CAC)mainly focus on uniaxial stress conditions.However,concrete structures often experience complex stress conditions in practical engineering.It is essential to investigate the mec...Studies on coral aggregate concrete(CAC)mainly focus on uniaxial stress conditions.However,concrete structures often experience complex stress conditions in practical engineering.It is essential to investigate the mechanical behavior and failure mechanisms of CAC under multiaxial stress conditions.This paper employs a 3D mesoscale model that considers the actual size,shape,and spatial distribution of aggregates.The reliability of the model and material parameters is verified through comparison with existing experimental data.Subsequently,the model is used to systematically study the mechanical properties,failure modes,and failure processes of C40 CAC under the biaxial compression.The numerical results are compared with the experimental results of CAC and ordinary portland concrete(OPC).The results indicate that the failure modes of CAC under the biaxial compression are diagonal shear failure.The biaxial compressive strength and elastic modulus of CAC are greater than those under uniaxial stress and exhibit a significant intermediate principal stress effect.The biaxial compressive strength reaches its maximum value when the stress ratio is 0.5,which is consistent with the conclusions for OPC.Finally,failure criteria and strength envelopes for CAC under the biaxial compression are established in order to provide a reference for analyzing the strength characteristics and structural design of CAC.展开更多
Desertification poses severe threats to socio-ecological resilience in arid regions,yet systematic quantification of desertification control efficiency remains limited.This study addressed this gap by developing an in...Desertification poses severe threats to socio-ecological resilience in arid regions,yet systematic quantification of desertification control efficiency remains limited.This study addressed this gap by developing an integrated Data Envelopment Analysis(DEA)Malmquist index to assess the spatiotemporal dynamics of desertification control efficiency in Hotan Prefecture(a hyper-arid region)of China from 2005 to 2023.To achieve this goal,we analyzed 5 indices spanning the total factor productivity,technical change,efficiency change,pure efficiency change,and scale efficiency change across 7 counties and 1 city in Hotan Prefecture.Results revealed that the growth rate of the total factor productivity is 12.0%,which is driven primarily by technical change and management optimization.However,significant spatiotemporal heterogeneity emerged.Temporally,rapid early gains during 2005–2010,with the total factor productivity value of 1.372,were dominated by technological progress,where technical change reached 1.291,while scale efficiency change helped sustain progress between 2010 and 2015.A recent decline in the total factor productivity to 0.987 during 2015–2023 underscored the risks associated with technological stagnation.Spatially,Qira County achieved the highest growth rate of the total factor productivity at 33.7%through dual advances in technology and management,which stands in sharp contrast to Moyu County's stagnation,where the total factor productivity reached only 1.029,reflecting the minimal growth rate of 2.9%.Furthermore,scale expansion change proved beneficial in Pishan County but counterproductive in Qira County.Based on these findings,this study proposes targeted policy recommendations to enhance desertification control efficiency in hyper-arid regions like Hotan Prefecture.It emphasizes the importance of continuous technological innovation,particularly water-saving and adaptive techniques to counteract declining productivity.Differentiated spatial strategies are essential,with tailored interventions for high-risk northern areas and scaling successful models from higher-efficiency southern zones.Optimizing project scale based on ecological carrying capacity rather than uncontrolled expansion is urged,along with strengthening cross-regional water resource coordination.Finally,establishing a data-driven monitoring and decision-support system could enable dynamic efficiency evaluations and evidence-based policy planning.This study provides a critical methodological framework for systematically quantifying desertification control efficiency in hyper-arid regions,establishing an empirical foundation for targeted ecological governance.展开更多
This paper presents a new criterion for determining the unloading points quantitatively and consistently in a multi-stage triaxial test.The radial strain gradient(RSG)is first introduced as an arc tangent function of ...This paper presents a new criterion for determining the unloading points quantitatively and consistently in a multi-stage triaxial test.The radial strain gradient(RSG)is first introduced as an arc tangent function of the rate of change of radial strain to time.RSG is observed to correlate closely with the stress state of a compressed sample,and reaches a horizontal asymptote as approaching failure.For a given rock type,RSG value at peak stress is almost the same,irrespective of the porosity and permeability.These findings lead to the development of RSG criterion:Unloading points can be precisely determined at the time when RSG reaches a pre-determined value that is a little smaller than or equal to the RSG at peak stress.The RSG criterion is validated against other criteria and the single-stage triaxial test on various types of rocks.Failure envelopes from the RSG criterion match well with those from single-stage tests.A practical procedure is recommended to use the RSG criterion:an unconfined compression or single-stage test is first conducted to determine the RSG at peak stress for one sample,the unloading point is then selected to be a value close to the RSG at peak stress,and the multi-stage test is finally performed on another sample using the pre-selected RSG unloading criterion.Generally,the RSG criterion is applicable for any type of rocks,especially brittle rocks,where other criteria are not suitable.Further,it can be practically implemented on the most available rock mechanical testing instruments.展开更多
UAV shipboard landing poses significant challenges in terms of safety and efficiency,due to the oscillatory ship motion caused by wave interactions and wind gusts,especially in rough sea states.To solve this issue,a f...UAV shipboard landing poses significant challenges in terms of safety and efficiency,due to the oscillatory ship motion caused by wave interactions and wind gusts,especially in rough sea states.To solve this issue,a flight envelope constrained fixed-time control strategy is proposed to achieve a reliable UAV landing on a maneuvering ship.Firstly,a sliding data window autoregressive model is designed to predict the ship's roll and pitch motions,which are accordingly utilized to identify an appropriate quiescent period for safe landing.Subsequently,a barrier-function-based nonsingular terminal sliding mode controller is developed to eliminate the tracking errors within the identified quiescent period,while ensuring the errors remain bounded to satisfy flight envelope constraints.In particular,lumped disturbance components are estimated by integrating a fixed-time disturbance observer and compensated in the controller.The key advantage of the proposed approach is that it well balances the control requirements between precise landing position and safe landing attitude,guaranteeing both steady-state performance and transient behavior of the tracking error.Finally,comparative Gazebo simulations in different sea state scenarios are conducted to verify the satisfactory control performance.展开更多
The stratospheric airship is affected by harsh conditions in the stratosphere environment.To ensure the safety of the airship,it is necessary to detect the material state of the airship envelope.Since digital image co...The stratospheric airship is affected by harsh conditions in the stratosphere environment.To ensure the safety of the airship,it is necessary to detect the material state of the airship envelope.Since digital image correlation possesses non-contact strain measurement ability,this paper explores the infuence of different shapes of the subset on measurement accuracy.Through the results,it is found that increasing the aspect ratio of subsets can improve the strain accuracy measured in the c-direction,and reducing the aspect ratio can improve the strain accuracy measured in the y-direction.This trend becomes more obvious as the strain increases.Based on this discovery,a subset adaptive algorithm is proposed.The feasibility of the algorithm is verified by experiments,and the precision of strain measurement can be effectively improved by adjusting the threshold value.Therefore,the algorithm can be utilized to increase the measurement accuracy in the larger strain direction without changing the size of the subset.展开更多
The correct evaluation of enterprise technological innovation performance is the premise and foundation to improve the efficiency of enterprise innovation.This paper first puts forward the index system of enterprise t...The correct evaluation of enterprise technological innovation performance is the premise and foundation to improve the efficiency of enterprise innovation.This paper first puts forward the index system of enterprise technological innovation performance evaluation,then establishes the model of technological innovation performance evaluation,explores the quantitative evaluation of enterprise innovation performance by using the DEA method,and finally makes an empirical study on the technological innovation performance of the TR enterprise.展开更多
基金the National Science and Technology Major Projects(2021YFC2300704)the National Key Research and Development Program of China(2021YFA1301402,2018YFA0903700)+3 种基金the Strategic Priority Research Program of Chinese Academy of Sciences(XDA24010400)Shanghai Municipal Science and Technology Major Project(ZD2021CY001)the National Natural Science Foundation of China(32270695,31972881)support from Lingang Laboratory(Shanghai,China)。
文摘Monkeypox was declared a global health emergency by the World Health Organization,and as of March 2023,86,000 confirmed cases and 111 deaths across 110 countries have been reported.Its causal agent,monkeypox virus(MPV)belongs to a large family of double-stranded DNA viruses,Orthopoxviridae,that also includes vaccinia virus(VACV)and others.MPV produces two distinct forms of viral particles during its replication cycles:the enveloped viron(EV)that is released via exocytosis,and the mature viron(MV)that is discharged through lysis of host cells.This study was designed to develop multi-valent m RNA vaccines against monkeypox EV and MV surface proteins,and examine their efficacy and mechanism of action.Four m RNA vaccines were produced with different combinations of surface proteins from EV(A35R and B6R),MV(A29L,E8L,H3L and M1R),or EV and MV,and were administered in Balb/c mice to assess their immunogenicity potentials.A dynamic immune response was observed as soon as seven days after initial immunization,while a strong Ig G response to all immunogens was detected with ELISA after two vaccinations.The higher number of immunogens contributed to a more robust total Ig G response and correlating neutralizing activity against VACV,indicating the additive potential of each immunogen in generating immune response and nullifying VACV infection.Further,the m RNA vaccines elicited an antigen-specific CD4^(+)T cell response that is biased towards Th1.The m RNA vaccines with different combinations of EVand MV surface antigens protected a mouse model from a lethal dose VACV challenge,with the EV and MV antigens-combined vaccine offering the strongest protection.These findings provide insight into the protective mechanism of multi-valent m RNAvaccines against MPV,and also the foundation for further development of effective and safe m RNA vaccines for enhanced protection against monkeypox virus outbreak.
基金sponsored by the National Natural Science Foundation of China(Grant Nos.U2442206,42205067,and 41922035)the National Key R&D Program of China(Grant No.2024YFC3013100)the Key Research Program of Frontier Sciences of CAS(Grant No.QYZDB-SSW-DQC017).
文摘This study reveals the critical role of multiscale interaction within the westerly wind bursts(WWBs)west of the MJO convection in modulating the prediction skill for the November MJO event during the DYNAMO(Dynamics of the Madden–Julian Oscillation)field campaign.The characteristics of the MJO convection envelope are obtained by the largescale precipitation tracking method,and a novel metric is introduced to quantify the prediction skill for the MJO convection in the ECMWF reforecast.The ECMWF forecast exhibits approximately 17 days in skillful prediction for the MJO convection—significantly lower than that derived from the global measure.The reforecast ensembles are further classified into high and low skill catalogs based on the mean prediction skill during the observed WWBs period.High-skill ensembles exhibit significantly enhanced low-level westerlies,amplified MJO convection,and reduced spatial separation between the low-level westerlies and MJO convection during the WWBs period,indicating stronger coupling between the large-scale circulation and the convection.Mechanistic analysis reveals that enhanced westerlies in high-skill ensembles can transfer more high-frequency energy to the MJO convection through the flux convergence of interaction energy for MJO convection development,resulting in better prediction skill.
文摘The formation and evolution of binary stars are key steps in star formation and evolution,and thus their research has become the core content of modern astronomical research.Although as early as 1976,Bodan Pachenski proposed the theory of the evolution of shared envelopes in binary stars,but it was never confirmed until 2022 when the Yunnan Astronomical Observatory of the Chinese Academy of Sciences and an Australian team first observed the phenomenon of shared envelope ejection in binary stars,which provided support for Bodan Pachenski’s theory,but the true formation mechanism and evolution process of binary stars remain undetermined.For this reason,the author of this paper has proposed a theory of the formation and evolution of binary stars based on the theory of the evolution of common envelopes in binary stars and the theory of tidal disruption events,laying a foundation for establishing a complete theory of star formation and evolution.
基金supported by the National Science and Technology Major Project of the Ministry of Science and Technology of China(No.2024ZD1200200).
文摘Oil-fired construction machinery(OCM)is a major source of urban air pollutants and CO_(2) emissions,and elec-trification is a crucial pathway for improving air quality and achieving China’s dual carbon goals;however,its feasibility has not been fully explored.This study uses data envelopment analysis and the analytic hierarchy process to establish a development potential index,covering technical efficiency,economic cost,application sce-narios,and charging time and range,with an empirical analysis conducted in Beijing.The findings indicated the high feasibility of replacing OCM with electric alternatives,especially within the low-power range.Based on 2023 registered coding dat1,it is projected that by 2030,electrification could reduce regional average con-centrations of CO,NO_(x),PM_(2.5) and VOCs by 12.2%to 56.4%and reduce CO_(2) by 11.7%to 56.9%.Owing to economic considerations,small-and medium-sized machinery are particularly feasible for electrification.Key recommendations include prioritizing the electrification of forklifts,lifting platforms,and small-sized machinery in high-emission areas,particularly in central urban districts.Policies such as carbon taxes,carbon markets,and performance grading systems are suggested to incentivize electrification,along with expanding high-emission restriction zones and improving energy infrastructure to support widespread electrification.
文摘Curtain wall systems have evolved from aesthetic facade elements into multifunctional building envelopes that actively contribute to energy efficiency and climate responsiveness.This reviewpresents a comprehensive examination of curtain walls from an energy-engineering perspective,highlighting their structural typologies(Stick and Unitized),material configurations,and integration with smart technologies such as electrochromic glazing,parametric design algorithms,and Building Management Systems(BMS).Thestudy explores the thermal,acoustic,and solar performance of curtain walls across various climatic zones,supported by comparative analyses and iconic case studies including Apple Park,Burj Khalifa,and Milad Tower.Key challenges—including installation complexity,high maintenance costs,and climate sensitivity—are critically assessed alongside proposed solutions.A central innovation of this work lies in framing curtain walls not only as passive architectural elements but as dynamic interfaces that modulate energy flows,reduce HVAC loads,and enhance occupant comfort.The reviewed data indicate that optimized curtain wall configurations—especially those integrating electrochromic glazing and BIPV modules—can achieve annual energy consumption reductions ranging fromapproximately 5%to 27%,depending on climate,control strategy,and facade typology.The findings offer a valuable reference for architects,energy engineers,and decision-makers seeking to integrate high-performance facades into future-ready building designs.
基金supported by the National Natural Science Foundation of China under Grant No.12301365supported by the National Natural Science Foundation of China under Grant No.2241200071Guangdong Basic and Applied Basic Research Foundation under Grant No.2023A1515110001。
文摘In this note,the authors revisit the envelope dimension reduction,which was first introduced for estimating a sufficient dimension reduction subspace without inverting the sample covariance.Motivated by the recent developments in envelope methods and algorithms,the authors refresh the envelope inverse regression as a flexible alternative to the existing inverse regression methods in dimension reduction.The authors discuss the versatility of the envelope approach and demonstrate the advantages of the envelope dimension reduction through simulation studies.
文摘Classical linear discriminant analysis(LDA)(Fisher,1936)implicitly assumes the classification boundary depends on only one linear combination of the predictors.This restriction can lead to poor classification in applications where the decision boundary depends on multiple linear combinations of the predictors.To overcome this challenge,the authors first project the predictors onto an envelope central space and then perform LDA based on the sufficient predictor.The performance of the proposed method in improving classification accuracy is demonstrated in both synthetic data and real applications.
基金supported by the National Social Science Fund of China under Grant 25CJL064.
文摘The carbon emission trading policy is a key policy for China to achieve its dual carbon goals.This paper aims to examine the emission-reduction effects,transmission mechanisms,and carbon-market efficiency of China’s carbon-emission trading policy from 2012 to 2023.We adopt the difference-in-differences(DID)model to analyze the effects of policy on emissions,and the empirical results from the DID model confirm that the pilot carbon emission trading policy has significantly reduced carbon emission intensity in pilot areas.Then we use the mediation model to study the transmission mechanism of the pilot carbon emission trading policy,and the mediation analysis demonstrates that the pilot carbon emission trading policy achieves emission abatement through four parallel transmission channels:scientific innovation,energy conservation,clean energy substitution,and industrial structure upgrading.Data envelopment analysis evaluates the carbon market efficiency of China.The result shows that the average carbon market efficiency of pilot areas has improved steadily,particularly from 2012 to 2023,especially in Beijing,Hubei,and Guangdong.Moreover,the efficiency of the national carbon market has shown an upward trend since its 2021 launch;it remains lower than the pilot average,constrained primarily by limited sectoral coverage,which impacts scale efficiency.
文摘The goal of the present work is to demonstrate the potential of Artificial Neural Network(ANN)-driven Genetic Algorithm(GA)methods for energy efficiency and economic performance optimization of energy efficiency measures in a multi-family house building in Greece.The energy efficiency measures include different heating/cooling systems(such as low-temperature and high-temperature heat pumps,natural gas boilers,split units),building envelope components for floor,walls,roof and windows of variable heat transfer coefficients,the installation of solar thermal collectors and PVs.The calculations of the building loads and investment and operating and maintenance costs of the measures are based on the methodology defined in Directive 2010/31/EU,while economic assumptions are based on EN 15459-1 standard.Typically,multi-objective optimization of energy efficiency measures often requires the simulation of very large numbers of cases involving numerous possible combinations,resulting in intense computational load.The results of the study indicate that ANN-driven GA methods can be used as an alternative,valuable tool for reliably predicting the optimal measures which minimize primary energy consumption and life cycle cost of the building with greatly reduced computational requirements.Through GA methods,the computational time needed for obtaining the optimal solutions is reduced by 96.4%-96.8%.
基金funding from the National Natural Science Foundation of China(Nos.22036002,92043302,21577165,21906176)China Postdoctoral Science Foundation (2018M641495)Strategic Priority Research Program of the Chinese Academy of Sciences(XDPB2002).
文摘Enveloped viruses have been the leading causative agents of viral epidemics in the past decade,including the ongoing coronavirus disease 2019 outbreak.In epidemics caused by enveloped viruses,direct contact is a common route of infection,while indirect transmissions through the environment also contribute to the spread of the disease,although their significance remains controversial.Bridging the knowledge gap regarding the influence of interfacial interactions on the persistence of enveloped viruses in the environment reveals the transmission mechanisms when the virus undergoes mutations and prevents excessive disinfection during viral epidemics.Herein,from the perspective of the driving force,partition efficiency,and viral survivability at interfaces,we summarize the viral and environmental characteristics that affect the environmental transmission of viruses.We expect to provide insights for virus detection,environmental surveillance,and disinfection to limit the spread of severe acute respiratory syndrome coronavirus 2.
基金This work was supported by the National Key Research&Development Program of China(grant Nos.2021YFA1201000 and 2018YFE0117800)the National Natural Science Foundation of China(grant No.82102204)+3 种基金National Natural Science Foundation of China(NSFC)key project(grant No.32030060)NSFC international collaboration key project(grant No.51861135103)The authors also appreciate the support of“the Beijing-Tianjin-Hebei Basic Research Cooperation Project”(19JCZDJC64100)the Science Fund for Creative Research Groups of Nature Science Foundation of Hebei Province(B2021201038).
文摘Enveloped RNA viruses are a group of viruses with an outer membrane derived from a host cell and a genome consisting of ribonucleic acid(RNA).These viruses rely on host cell machinery and organelles to replicate and assemble new virus particles.However,the interaction between viruses and host organelles may be disrupted by nanomaterials,such as gold nanoparticles(AuNPs)with unique physical and chemical properties.In this study,we investigated the effects of AuNPs with different surface charge properties on the subcellular structure and function of mammalian cells,and their effects on two representative enveloped RNA viruses:lentivirus and human coronavirus OC43(HCoV-OC43)antiviral potential.By comparing the subcellular effects of AuNPs with different surface charge properties,we found that treatment with AuNPs with positive surface charges induced more significant disruption of subcellular structures than neutrally charged AuNPs and negatively charged AuNPs,mainly manifested in lysosomes and Cytoskeletal disorders.The antiviral effect of the surface positively charged AuNPs was further evaluated using lentivirus and HCoV-OC43.The results showed that AuNPs had a significant inhibitory effect on both lentivirus and HCoV-OC43 without obvious side effects.In conclusion,our study provides insights into the mechanism of action and biocompatibility of AuNP in biological systems,while supporting the potential of targeting organelle dynamics against enveloped RNA viruses.
基金supported by the Natural Science Foundation of Sichuan Province,China(2024NSFSC1272)the Innovation Team Development Funds for Sichuan Mutton Goat&Sheep,China(SCCXTD-2024-14)Scientific and Technological Innovation Team for Qinghai-Tibetan Plateau Research in Southwest Minzu University,China(2024CXTD08)。
文摘Bocapavovirus,a member of the genus Bocaparvovirus within the subfamily Parvovirinae and the family Parvoviridae,is a small,non-enveloped,single-stranded DNA virus.This pathogen poses health risks to both humans and animals.The Bocaparvovirus genome.
基金the National Science and Technology Major Project of China(No.2019-VII0017e0158)the National Natural Science Foundation of China(No.U21A20131)+1 种基金the Industry-University Research Cooperation Project,China(No.HFZL2020CXY025)the National Key Laboratory of Science and Technology on Helicopter Transmission,China(No.HTL-O-21G05).
文摘Spiral bevel gears are critical transmission components,and are widely used in the aerospace field.This paper proposes a new multi-DOF envelope forming process for fabricating spiral bevel gears.Firstly,the multi-DOF envelope forming principle of spiral bevel gears is proposed.Secondly,the design methods for the envelope tool geometry and movement are proposed based on the envelope geometry and movement relationships.Thirdly,the metal flow and tooth filling laws are revealed through 3D FE simulation of the multi-DOF envelope forming process of a typical spiral bevel gear.Fourthly,a new method for separating the envelope tool and the formed spiral bevel gear with back taper tooth is proposed to avoid their interference.Finally,experiments on multi-DOF envelope forming of this typical spiral bevel gear are conducted using new heavy load multi-DOF envelope forming equipment.The simulation and experimental results show the feasibility of the proposed multi-DOF envelope forming process for fabricating spiral bevel gears with back taper tooth and the corresponding process design methods.
文摘Ports are crucial to the economy of many nations;thus, numerous studies have been conducted on port efficiency and productivity. This study analyses the efficiency and productivity of some major global ports namely, Port of Singapore, Rotterdam, Antwerp and Durban. The main objectives of this study are to determine the level of operational efficiency of the mentioned ports, measure and evaluate the ports’ productivity changes and lastly to investigate the factors influencing the productivity changes of the ports studied. To achieve these objectives, Data Envelopment Analysis (DEA-BCC) model was used to determine the technical and operational efficiencies of the ports and Malmquist productivity index was employed to calculate the various productivity levels. The results of the study can guide stakeholders to formulate their operational strategies for port efficiency and productivity. The study also has policy suggestions that are uniquely targeted to Africa’s issues and potential.
基金supported by the National Science Foundations of China(Nos.52078250,51878350,11832013,51678304,51508272)。
文摘Studies on coral aggregate concrete(CAC)mainly focus on uniaxial stress conditions.However,concrete structures often experience complex stress conditions in practical engineering.It is essential to investigate the mechanical behavior and failure mechanisms of CAC under multiaxial stress conditions.This paper employs a 3D mesoscale model that considers the actual size,shape,and spatial distribution of aggregates.The reliability of the model and material parameters is verified through comparison with existing experimental data.Subsequently,the model is used to systematically study the mechanical properties,failure modes,and failure processes of C40 CAC under the biaxial compression.The numerical results are compared with the experimental results of CAC and ordinary portland concrete(OPC).The results indicate that the failure modes of CAC under the biaxial compression are diagonal shear failure.The biaxial compressive strength and elastic modulus of CAC are greater than those under uniaxial stress and exhibit a significant intermediate principal stress effect.The biaxial compressive strength reaches its maximum value when the stress ratio is 0.5,which is consistent with the conclusions for OPC.Finally,failure criteria and strength envelopes for CAC under the biaxial compression are established in order to provide a reference for analyzing the strength characteristics and structural design of CAC.
基金funded by the National Key Research and Development Program of China(2023YFF0805603)。
文摘Desertification poses severe threats to socio-ecological resilience in arid regions,yet systematic quantification of desertification control efficiency remains limited.This study addressed this gap by developing an integrated Data Envelopment Analysis(DEA)Malmquist index to assess the spatiotemporal dynamics of desertification control efficiency in Hotan Prefecture(a hyper-arid region)of China from 2005 to 2023.To achieve this goal,we analyzed 5 indices spanning the total factor productivity,technical change,efficiency change,pure efficiency change,and scale efficiency change across 7 counties and 1 city in Hotan Prefecture.Results revealed that the growth rate of the total factor productivity is 12.0%,which is driven primarily by technical change and management optimization.However,significant spatiotemporal heterogeneity emerged.Temporally,rapid early gains during 2005–2010,with the total factor productivity value of 1.372,were dominated by technological progress,where technical change reached 1.291,while scale efficiency change helped sustain progress between 2010 and 2015.A recent decline in the total factor productivity to 0.987 during 2015–2023 underscored the risks associated with technological stagnation.Spatially,Qira County achieved the highest growth rate of the total factor productivity at 33.7%through dual advances in technology and management,which stands in sharp contrast to Moyu County's stagnation,where the total factor productivity reached only 1.029,reflecting the minimal growth rate of 2.9%.Furthermore,scale expansion change proved beneficial in Pishan County but counterproductive in Qira County.Based on these findings,this study proposes targeted policy recommendations to enhance desertification control efficiency in hyper-arid regions like Hotan Prefecture.It emphasizes the importance of continuous technological innovation,particularly water-saving and adaptive techniques to counteract declining productivity.Differentiated spatial strategies are essential,with tailored interventions for high-risk northern areas and scaling successful models from higher-efficiency southern zones.Optimizing project scale based on ecological carrying capacity rather than uncontrolled expansion is urged,along with strengthening cross-regional water resource coordination.Finally,establishing a data-driven monitoring and decision-support system could enable dynamic efficiency evaluations and evidence-based policy planning.This study provides a critical methodological framework for systematically quantifying desertification control efficiency in hyper-arid regions,establishing an empirical foundation for targeted ecological governance.
文摘This paper presents a new criterion for determining the unloading points quantitatively and consistently in a multi-stage triaxial test.The radial strain gradient(RSG)is first introduced as an arc tangent function of the rate of change of radial strain to time.RSG is observed to correlate closely with the stress state of a compressed sample,and reaches a horizontal asymptote as approaching failure.For a given rock type,RSG value at peak stress is almost the same,irrespective of the porosity and permeability.These findings lead to the development of RSG criterion:Unloading points can be precisely determined at the time when RSG reaches a pre-determined value that is a little smaller than or equal to the RSG at peak stress.The RSG criterion is validated against other criteria and the single-stage triaxial test on various types of rocks.Failure envelopes from the RSG criterion match well with those from single-stage tests.A practical procedure is recommended to use the RSG criterion:an unconfined compression or single-stage test is first conducted to determine the RSG at peak stress for one sample,the unloading point is then selected to be a value close to the RSG at peak stress,and the multi-stage test is finally performed on another sample using the pre-selected RSG unloading criterion.Generally,the RSG criterion is applicable for any type of rocks,especially brittle rocks,where other criteria are not suitable.Further,it can be practically implemented on the most available rock mechanical testing instruments.
文摘UAV shipboard landing poses significant challenges in terms of safety and efficiency,due to the oscillatory ship motion caused by wave interactions and wind gusts,especially in rough sea states.To solve this issue,a flight envelope constrained fixed-time control strategy is proposed to achieve a reliable UAV landing on a maneuvering ship.Firstly,a sliding data window autoregressive model is designed to predict the ship's roll and pitch motions,which are accordingly utilized to identify an appropriate quiescent period for safe landing.Subsequently,a barrier-function-based nonsingular terminal sliding mode controller is developed to eliminate the tracking errors within the identified quiescent period,while ensuring the errors remain bounded to satisfy flight envelope constraints.In particular,lumped disturbance components are estimated by integrating a fixed-time disturbance observer and compensated in the controller.The key advantage of the proposed approach is that it well balances the control requirements between precise landing position and safe landing attitude,guaranteeing both steady-state performance and transient behavior of the tracking error.Finally,comparative Gazebo simulations in different sea state scenarios are conducted to verify the satisfactory control performance.
文摘The stratospheric airship is affected by harsh conditions in the stratosphere environment.To ensure the safety of the airship,it is necessary to detect the material state of the airship envelope.Since digital image correlation possesses non-contact strain measurement ability,this paper explores the infuence of different shapes of the subset on measurement accuracy.Through the results,it is found that increasing the aspect ratio of subsets can improve the strain accuracy measured in the c-direction,and reducing the aspect ratio can improve the strain accuracy measured in the y-direction.This trend becomes more obvious as the strain increases.Based on this discovery,a subset adaptive algorithm is proposed.The feasibility of the algorithm is verified by experiments,and the precision of strain measurement can be effectively improved by adjusting the threshold value.Therefore,the algorithm can be utilized to increase the measurement accuracy in the larger strain direction without changing the size of the subset.
文摘The correct evaluation of enterprise technological innovation performance is the premise and foundation to improve the efficiency of enterprise innovation.This paper first puts forward the index system of enterprise technological innovation performance evaluation,then establishes the model of technological innovation performance evaluation,explores the quantitative evaluation of enterprise innovation performance by using the DEA method,and finally makes an empirical study on the technological innovation performance of the TR enterprise.
