Based on micro-survey data from 894 farmers in Sichuan Province,this study employs the Ordinary Least Squares(OLS),Two-Stage Least Squares(2SLS),mediating effect,and moderating effect models to comprehensively analyze...Based on micro-survey data from 894 farmers in Sichuan Province,this study employs the Ordinary Least Squares(OLS),Two-Stage Least Squares(2SLS),mediating effect,and moderating effect models to comprehensively analyze the mechanisms and effects of digital literacy in empowering farmers’common prosperity.Endogeneity and robustness are addressed using the Sobel test,the Bootstrap,and moderating effect plots.The findings indicate that first,after controlling for variables such as age,gender,and planting years,digital literacy significantly and positively influences the common prosperity of farmers at the 5%level;second,enhanced digital literacy promotes higher levels of technology adoption and information accumulation among farmers,thereby increasing the probability of achieving common prosperity.The mediating effects of technology adoption and information sharing account for 21.10%and 33.94%of the total effect,respectively;and third,the information environment and financial empowerment play positive moderation roles in the effect of digital literacy on farmers’common prosperity,with the moderation effects significant at the 1%and 10%levels,respectively.Therefore,we recommend policies that enhance the access of farmers to digital literacy training,strengthen rural digital infrastructure,establish integrated rural information-sharing platforms,and create an enabling environment for the adoption of digital technologies.展开更多
In the context of rapid urbanization and industrialization,achieving a coordinated relationship between urban construction land expansion(UCLE)and economic growth is essential for sustainable development,especially in...In the context of rapid urbanization and industrialization,achieving a coordinated relationship between urban construction land expansion(UCLE)and economic growth is essential for sustainable development,especially in developing countries.This study examined the spatiotemporal relationship between UCLE and economic growth in the Yellow River Basin(YRB),China from 2000 to 2020.An extended IPAT(Impact=Population×Affluence×Technology)decoupling framework and the geographical detector model were employed at a 5-km grid scale.Results show that urban construction land(UCL)expanded slowly before 2005,accelerated between 2005 and 2015,and declined thereafter.Since 2015,UCLE in most parts of the YRB has gradually decoupled from economic growth.The geographical detector analysis revealed that economic growth,along with its interactions with natural,locational,and socioeconomic factors,significantly influenced UCLE.Notably,location factors have gained importance since 2015,reducing the role of economic growth as the primary driver of UCLE in the YRB’s lower reaches.Nonetheless,economic growth continues to significantly influence the upper and middle reaches.These findings highlight the need for more precise and differentiated strategies for land utilization and economic growth,tailored to finer spatial scales,to better integrate human-land systems and promote high-quality regional development.展开更多
The author’s combined numerical model consisting of a third generation shallow water wave model and a 3 D tide surge model with wave dependent surface wind stress were used to study the influence of waves on tide sur...The author’s combined numerical model consisting of a third generation shallow water wave model and a 3 D tide surge model with wave dependent surface wind stress were used to study the influence of waves on tide surge motion. For the typical weather case, in this study, the magnitude and mechanism of the influence of waves on tide surges in the Bohai Sea were revealed for the first time. The results showed that although consideration of the wave dependent surface wind stresses raise slightly the traditional surface wind stress, due to the accumulated effects, the computed results are improved on the whole. Storm level maximum modulation can reach 0.4 m. The results computed by the combined model agreed well with the measured data.展开更多
To investigate the influence of coarse aggregate parent rock properties on the elastic modulus of concrete,the mineralogical properties and stress-strain curves of granite and dolomite parent rocks,as well as the stre...To investigate the influence of coarse aggregate parent rock properties on the elastic modulus of concrete,the mineralogical properties and stress-strain curves of granite and dolomite parent rocks,as well as the strength and elastic modulus of mortar and concrete prepared with mechanism aggregates of the corresponding lithology,and the stress-strain curves of concrete were investigated.In this paper,a coarse aggregate and mortar matrix bonding assumption is proposed,and a prediction model for the elastic modulus of mortar is established by considering the lithology of the mechanism sand and the slurry components.An equivalent coarse aggregate elastic modulus model was established by considering factors such as coarse aggregate particle size,volume fraction,and mortar thickness between coarse aggregates.Based on the elastic modulus of the equivalent coarse aggregate and the remaining mortar,a prediction model for the elastic modulus of the two and three components of concrete in series and then in parallel was established,and the predicted values differed from the measured values within 10%.It is proposed that the coarse aggregate elastic modulus in highstrength concrete is the most critical factor affecting the elastic modulus of concrete,and as the coarse aggregate elastic modulus increases by 27.7%,the concrete elastic modulus increases by 19.5%.展开更多
In recent years,supercritical CO_(2)flooding has become an effective method for developing lowpermeability reservoirs.In supercritical CO_(2)flooding different factors influence the mechanism of its displacement proce...In recent years,supercritical CO_(2)flooding has become an effective method for developing lowpermeability reservoirs.In supercritical CO_(2)flooding different factors influence the mechanism of its displacement process for oil recovery.Asynchronous injection-production modes can use supercritical CO_(2)to enhance oil recovery but may also worsen the injection capacity.Cores with high permeability have higher oil recovery rates and better injection capacity,however,gas channeling occurs.Supercritical CO_(2)flooding has a higher oil recovery at high pressure levels,which delays the occurrence of gas channeling.Conversely,gas injection has lower displacement efficiency but better injection capacity at the high water cut stage.This study analyzes the displacement characteristics of supercritical CO_(2)flooding with a series of experiments under different injection and production parameters.Experimental results show that the gas breakthrough stage has the fastest oil production and the supercritical CO_(2)injection capacity variation tendency is closely related to the gas-oil ratio.Further experiments show that higher injection rates represent significant ultimate oil recovery and injection index,providing a good reference for developing low-permeability reservoirs.展开更多
The development of cancer is a complex process that requires the participation of many factors,including mutations in genes, regulation of signaling pathways, disruption of homeostasis, and failure of self-monitoring ...The development of cancer is a complex process that requires the participation of many factors,including mutations in genes, regulation of signaling pathways, disruption of homeostasis, and failure of self-monitoring mechanisms. Sufficient evidence has展开更多
The study of pressure stimulated current(PSC)changes of rocks is significant to monitor dynamic disasters in mines and rock masses.The existing studies focus on change laws and mechanism of currents generated under th...The study of pressure stimulated current(PSC)changes of rocks is significant to monitor dynamic disasters in mines and rock masses.The existing studies focus on change laws and mechanism of currents generated under the loading of rocks.An electrical and mechanics test system was established in this paper to explore the impacts of loading rates on PSCs.The results indicated that PSC curves of different rocks had different change laws under low/high loading rates.When the loading rate was relatively low,PSC curves firstly changed gently and then increased exponentially.Under high loading rates,PSC curves experienced the rapid increase stage,gentle increase stage and sudden change stage.The compressive strength could greatly affect the peak PSC in case of rock failure.The loading rate was a key factor in average PSC.Under low loading rates,the variations of PSCs conformed to the damage charge model of fracture mechanics,while they did not at the fracture moment.Under high loading rates,the PSCs at low stress didn’t fit the model due to the stress impact effects.The experimental results could provide theoretical basis for the influence of loading rates on PSCs.展开更多
[Objective] The research aimed to study the possible mechanism of terrain effect on cold-flow snowstorm.[Method] By using the meso-scale numerical model(WRF),a cold-flow snowstorm weather process in Shandong Peninsula...[Objective] The research aimed to study the possible mechanism of terrain effect on cold-flow snowstorm.[Method] By using the meso-scale numerical model(WRF),a cold-flow snowstorm weather process in Shandong Peninsula was carried out numerical simulation and terrain sensitivity contrast test.The possible reason of terrain effect on falling zone and strength of snowstorm was deeply analyzed from water vapor,thermodynamic field and so on.[Result] The mountain terrain in Shandong Peninsula had great influences on falling zone and strength of cold-flow snowstorm.The strength of snowstorm obviously increased,and the snowfall center obviously moved northward.The main reason was that terrain caused the low-level wind field convergence and vertical movement in the troposphere strengthened.Then,the spatial distribution of water vapor and snow water content in the cold-flow snowstorm process obviously changed.So,the whole snowstorm process was affected.[Conclusion] The mountain terrain in Shandong Peninsula was the important element which needed to be focused on considering in the forecast analysis of cold-flow snowstorm weather process.展开更多
Effect of mechanical stress on magnetic properties of an exchange-biased ferromagnetic/antiferromagnetic bilayer deposited on a flexible substrate is investigated. The hysteresis loops with different magnitudes and or...Effect of mechanical stress on magnetic properties of an exchange-biased ferromagnetic/antiferromagnetic bilayer deposited on a flexible substrate is investigated. The hysteresis loops with different magnitudes and orientations of the stress can be classified into three types. The corresponding physical conditions for each type of the loop are deduced based on the principle of minimal energy. The equation of the critical stress is derived, which can judge whether the loops show hysteresis or not. Numerical calculations suggest that except for the magnitude of the mechanical stress, the relative orientation of the stress is also an important factor to tune the exchange bias effect.展开更多
In this paper, the relation between Asian summer monsoon circulation and sea surface temperature anomalies over equatorial central-eastern Pacific is investigated by using a global spectral model. This model has nine ...In this paper, the relation between Asian summer monsoon circulation and sea surface temperature anomalies over equatorial central-eastern Pacific is investigated by using a global spectral model. This model has nine layers in the vertical and the model variables are represented in the horizontal as truncated expansions of the surface spherical harmonics with rhomboidal truncation at wave number 15. The model involves comparatively complete physical processes and parameterizations with mountains.Using the above model, two experimental schemes are designed, namely control case and anomalous sea surface temperature case. The above two schemes are respectively integrated for forty days and the simulated results are obtained from the last 30-day averaged simulations.The simulations show that positive SST anomalies over equatorial central-eastern Pacific weakens Indian monsoon circulation,decreases precipitation in Indian sub-continent whereas it intensifies East Asian monsoon circulation and increases precipitation in East Asian area. All these results reflect the characteristics of Asian summer monsoon during the El Nino period. In this paper, SST anomalies over equatorial central-eastern Pacific have a direct influence on the intensity and position of subtropical high via the wave train over Northern Hemisphere, which is similar to that suggested by Nitta(1987) and the wave train over Southern Hemisphere has an influence on the intensity of Muscarene high and Australia high resulting in affecting cross equatorial flow. As a result, atmospheric interior heat sources and sinks are redistributed because of the change of cross equatorial flow. And the response of atmosphere to the new heat source and sink has a significant influence on Asian summer monsoon.展开更多
On the basis of combing domestic and foreign related literature and research practice,the influence mechanism of the construction of new liberal arts was analyzed,and the fundamental tasks of the construction of new l...On the basis of combing domestic and foreign related literature and research practice,the influence mechanism of the construction of new liberal arts was analyzed,and the fundamental tasks of the construction of new liberal arts in Tibet were summarized.Based on 173 field questionnaires in Tibet,factor analysis was used to conduct empirical analysis.It is found that the cumulative contribution of the first,second,third and fourth common factor was 24.921%,21.742%,17.331%,and 14.206%,respectively.Professional orientation,the reform of talent training mode,teacher ability,quality and level of the teaching team,curriculum system reform,teaching content reform,education training service,and other evaluation indicators are the key points of the construction of new liberal arts.The research conclusion is that the construction of new liberal arts needs to highlight the"three positions";it is needed to plan and promote various resources to focus on the ability and level of professional teachers’social services;the managers and professional teachers should be the leaders and participants of the innovation of the talent training model respectively.Finally,relevant policy recommendations were put forward.展开更多
This paper deals with the characteristics of silicon modification with lanthanum of Al-Si eutectic alloy in sand mold and metal mold with optical microscopy,scanning electron microscopy,electron microprobe and X-ray d...This paper deals with the characteristics of silicon modification with lanthanum of Al-Si eutectic alloy in sand mold and metal mold with optical microscopy,scanning electron microscopy,electron microprobe and X-ray diffractometer.It is found that the amount of lanthanum,liquid alloy condition,holding time and stir- ring liquid influence the modification of silicon.The modification of silicon with lanthanum is of long effectiveness and has a“incubation time”.The modification can improve the ductility(δ_s)and tensile strength (σ_b)of the alloy,but their maximum values are not corresponding to the same amount of lanthanum.展开更多
With the economic development and multicultural exchange of ethnic villages,more and more ethnic villages have embarked on the road of tourism to become rich,but also brought the problem of ecological pollution.Few ex...With the economic development and multicultural exchange of ethnic villages,more and more ethnic villages have embarked on the road of tourism to become rich,but also brought the problem of ecological pollution.Few existing literatures discuss how to alleviate the ecological pollution in ethnic villages from the perspective of tourists’environmentally responsible behavior.In the context of ethnic villages,from the perspective of integration and the attitude-context-behavior theory,this paper constructs an EV-ABC-TERB model with four variables,namely environmental attitude,local atmosphere,emotional experience and tourists’environmentally responsible behavior,to explore the characteristics,influencing factors and influencing mechanism of tourists’environmental responsibility behavior in ethnic villages.Taking Xijiang Hmong Village as the research case,questionnaire survey method and structural equation model method were used.The results show that environmental attitude positively affects emotional experience and tourists’environmentally responsible behavior.Local atmosphere positively influences tourists’environmentally responsible behavior.Emotional experience negatively affects tourists’environmentally responsible behavior and plays an intermediary role in the way that environmental attitudes affect tourists’environmentally responsible behavior.The influence of environmental attitude on emotional experience is negatively regulated by local atmosphere.Finally,based on the analysis conclusion,it provides new ideas and inspiration for the sustainable development of the ethnic village tourism.展开更多
With the rapid development of China’s economy,the coordinated development of resident income and GDP has become an important indicator to measure local economic development.How to realize the synergistic growth of th...With the rapid development of China’s economy,the coordinated development of resident income and GDP has become an important indicator to measure local economic development.How to realize the synergistic growth of the two in the new era is of great significance for promoting the sustainable development of the local economy.Based on the theory of the coordinated development of resident income and GDP,this paper will take Shandong Province as an example to analyze the interaction between resident income growth and GDP,find out the influencing factors that restrict the coordinated development of resident income and GDP,and explore the impact of the coordinated development of resident income and GDP on local economic development.Finally,relevant policies will be studied.How to effectively increase residents’income,promote the sustainable and healthy development of the local economy,and put forward relevant suggestions to promote the coordinated development of residents’income and GDP.展开更多
High entropy materials(HEMs)show great potential as electrocatalysts for oxygen evolution reaction(OER)thanks to their interesting four-core effect.This paper presents the first systematic summary of the key factors i...High entropy materials(HEMs)show great potential as electrocatalysts for oxygen evolution reaction(OER)thanks to their interesting four-core effect.This paper presents the first systematic summary of the key factors in the synthetic methods and their influence on the structure and OER properties of HEMs(including complexing agent,synthetic temperature,and calcination atmosphere).Optimizing the components of high entropy alloys and compounds by introducing heteroatoms(such as O,S,P,N,C,and B)can enhance the chemical configurations of active sites and thus enhance the intrinsic OER kinetics.In addition,this paper emphasizes the importance of the electrocatalytic influence mechanism of the four-core effects(including the high entropy effect,lattice distortion effect,cocktail effect and sluggish diffusion effect)on catalyst structure and their OER performance.Finally,we outline the current challenges and future development directions,aiming to offer crucial insights for creating economical and efficient HEM-based electrocatalysts in the OER field.展开更多
Throughout versatile metal compositions and unique structural characteristics,polynary metal atom catalysts(PACs)readily harness synergistic intermetallic effects,significantly boosting the catalytic performances.Thes...Throughout versatile metal compositions and unique structural characteristics,polynary metal atom catalysts(PACs)readily harness synergistic intermetallic effects,significantly boosting the catalytic performances.These catalysts are featured by favorable catalytic activity,stability and selectivity,offering avenues to tackle challenges in energy conversion,environmental protection and chemical synthesis.Nevertheless,an in-depth understanding and comprehensive summary of the structure-performance relationship for the emerging PACs remains elusive.This review embarks from the classification of PACs,delving further into the origins of catalytic activity and mechanisms underpinning performance enhancement.At the beginning,it outlines the fundamental concepts,preparation methods and accurate recognition of PACs.Subsequently,it centers on discussing the origins of activity,strategies for performance optimization,mechanisms of action,and application scenarios across diverse catalytic reactions.Moreover,the unexplored issues and future perspectives of PACs are proposed at the end,stating their pivotal roles in advancing green chemistry and the sustainable energy realm.This review overall aims to provide valuable insight and guidance for the preparation and application of PACs.展开更多
Rockburst are often encountered in tunnel construction due to the complex geological conditions.To study the influence of unloading rate on rockburst,gneiss rockburst experiments were conducted under three groups of u...Rockburst are often encountered in tunnel construction due to the complex geological conditions.To study the influence of unloading rate on rockburst,gneiss rockburst experiments were conducted under three groups of unloading rates.A high-speed photography system and acoustic emission(AE)system were used to monitor the entire process of rockburst process in real-time.The results show that the intensity of gneiss rockburst decreases with decrease of unloading rate,which is manifested as the reduction of AE energy and fragments ejection velocity.The mechanisms are proposed to explain this effect:(i)The reduction of unloading rate changes the crack propagation mechanism in the process of rockburst.This makes the rockbursts change from the tensile failure mechanism at high unloading rate to the tension-shear mixed failure mechanism at low unloading rate,and more energy released in the form of shear crack propagation.Then,less strain energy is converted into kinetic energy of fragments ejection.(ii)Less plate cracking degree of gneiss has taken shape due to decrease of unloading rate,resulting in the destruction of rockburst incubation process.The enlightenments of reducing the unloading rate for the project are also described quantitatively.The rockburst magnitude is reduced from the medium magnitude at the unloading rate of 0.1 MPa/s to the slight magnitude at the unloading rate of 0.025 MPa/s,which was judged by the ejection velocity.展开更多
Urbanization significantly affects the balance of key elements such as water,heat,and carbon in cities.However,previous studies have not integrated these factors for comprehensive analysis.Here,we proposed a waterheat...Urbanization significantly affects the balance of key elements such as water,heat,and carbon in cities.However,previous studies have not integrated these factors for comprehensive analysis.Here,we proposed a waterheat-carbon(WHC)nexus model to provide a holistic understanding of urbanization's impacts.Furthermore,we employed the model to identify the mechanisms and response thresholds of urbanization through this coupling approach.Our findings reveal three key insights:(1)WHC exhibits a nonlinear,inverted S-shaped response to urbanization.(2)The mechanisms through which urbanization impacts WHC differ significantly across urbanization gradients.Acrossing urbanization gradients,the complexity of impact pathways increases,with direct effects becoming more pronounced and positive impact pathways emerging progressively.(3)We identified priority zones for restoration and protection based on the likelihood of units shifting between lower-risk and higher-risk categories.Our study enhances understanding of the WHC-urbanization nexus and highlights the importance of accounting for threshold effects and environmental interactions when examining the impact between urbanization and WHC.This framework can be adapted to other urban areas experiencing similar challenges.展开更多
Digital village construction opens a new vista for fulfilling consumption capabilities and optimizing consumption patterns in rural areas.For this research,we used the microdata on rural households from the 2019 China...Digital village construction opens a new vista for fulfilling consumption capabilities and optimizing consumption patterns in rural areas.For this research,we used the microdata on rural households from the 2019 China Household Finance Survey(CHFS)to conduct an empirical examination of the impact of digital village construction on the upgrading of rural household consumption and its possible influence mechanisms in the endogenous switching regression(ESR)model.Our research findings can be summarized in three points.First,digital village construction has significantly contributed positive contributions to the improvements and upgrading of rural household consumption.Second,digital village construction can help upgrade rural household consumption by increasing their participation in online shopping and expanding online shopping channels.Third,digital village construction means different things to rural households at different levels of risk exposure,with its facilitation to consumption upgrades in proportion to income risks facing rural households.Our research findings,which came from an extensive,in-depth exploration of the factors influencing rural household consumption,are of practical significance and policy value to the stimulating and fulfilling of consumption potentials among rural households.展开更多
Based on multiple remote-sensing image interpretation and classification, and economic and social data, this study focused on rural settlement and land use change amidst rapid urbanization. Rural settlements, spatial ...Based on multiple remote-sensing image interpretation and classification, and economic and social data, this study focused on rural settlement and land use change amidst rapid urbanization. Rural settlements, spatial and temporal patterns of land use and influ- encing factors in the Bohai Rim were explored within 5x5 km grid cells, as per GIS spatial analysis and geostatistical analysis. Results show that the spatial distribution of rural settle- ments in the Bohai Rim is remarkably varied. The number of rural settlement sites in a 5x5 km grid cell exceeding 5.0 are distributed in a six-area pattern in the Bohai Rim; rural settlement dispersion is particularly high in agricultural regions in south Hebei and southwest Shandong, suggesting rural settlement density keeps increasing from northeast to southwest, charac- terized by high density and dispersed spatial distribution in traditional agricultural regions. Furthermore, rural settlements show dramatic spatial differences in terms of distribution and dynamic change degrees in the Bohai Rim. In terms of spatial distribution, rural residential land is always extensive in plains, with a high density of rural settlements, on the North China Plain in particular, and rural residential land in the south of Shandong province is also exten- sive, with most rural settlement land use areas in the 5x5 km grid cells exceeding 3 km2. However, traditional agricultural regions have underdeveloped economies, industrialization and tertiary industries, characterized by low urbanization rates, with farmers not feeling as- similated in rural or urban areas. In terms of the temporal sequence, urban expansion rapidly promotes the transformation of rural residential lands in rural-urban transitional belts of pro- vincial capital or prefecture-level city into urban lands, and in traditional rural areas, residen- tial lands are growing. The natural environment, transportation conditions, economic devel- opment and farmers＇ incomes all have effects on type of land use change and pattern of rural settlements. It is a core objective for future rural development to reconstruct a rational spatial pattern of villages or towns and well-organized village-town systems, build central villages, key towns or central towns, optimize or reconstruct production, living and eco-space of rural areas. It is of significance for rural geographical research to further interpret and explore spatial reconstruction theory.展开更多
基金a phased achievement of“Research on the Digital Transformation Mechanism and Policies of the Agricultural Industry in the Chengdu-Chongqing Economic Circle”(Ref.:24YBCY03),a project funded by the Sichuan Academy of Social Sciences。
文摘Based on micro-survey data from 894 farmers in Sichuan Province,this study employs the Ordinary Least Squares(OLS),Two-Stage Least Squares(2SLS),mediating effect,and moderating effect models to comprehensively analyze the mechanisms and effects of digital literacy in empowering farmers’common prosperity.Endogeneity and robustness are addressed using the Sobel test,the Bootstrap,and moderating effect plots.The findings indicate that first,after controlling for variables such as age,gender,and planting years,digital literacy significantly and positively influences the common prosperity of farmers at the 5%level;second,enhanced digital literacy promotes higher levels of technology adoption and information accumulation among farmers,thereby increasing the probability of achieving common prosperity.The mediating effects of technology adoption and information sharing account for 21.10%and 33.94%of the total effect,respectively;and third,the information environment and financial empowerment play positive moderation roles in the effect of digital literacy on farmers’common prosperity,with the moderation effects significant at the 1%and 10%levels,respectively.Therefore,we recommend policies that enhance the access of farmers to digital literacy training,strengthen rural digital infrastructure,establish integrated rural information-sharing platforms,and create an enabling environment for the adoption of digital technologies.
基金Under the auspices of National Natural Science Foundation of China(No.42293271,42471222)。
文摘In the context of rapid urbanization and industrialization,achieving a coordinated relationship between urban construction land expansion(UCLE)and economic growth is essential for sustainable development,especially in developing countries.This study examined the spatiotemporal relationship between UCLE and economic growth in the Yellow River Basin(YRB),China from 2000 to 2020.An extended IPAT(Impact=Population×Affluence×Technology)decoupling framework and the geographical detector model were employed at a 5-km grid scale.Results show that urban construction land(UCL)expanded slowly before 2005,accelerated between 2005 and 2015,and declined thereafter.Since 2015,UCLE in most parts of the YRB has gradually decoupled from economic growth.The geographical detector analysis revealed that economic growth,along with its interactions with natural,locational,and socioeconomic factors,significantly influenced UCLE.Notably,location factors have gained importance since 2015,reducing the role of economic growth as the primary driver of UCLE in the YRB’s lower reaches.Nonetheless,economic growth continues to significantly influence the upper and middle reaches.These findings highlight the need for more precise and differentiated strategies for land utilization and economic growth,tailored to finer spatial scales,to better integrate human-land systems and promote high-quality regional development.
文摘The author’s combined numerical model consisting of a third generation shallow water wave model and a 3 D tide surge model with wave dependent surface wind stress were used to study the influence of waves on tide surge motion. For the typical weather case, in this study, the magnitude and mechanism of the influence of waves on tide surges in the Bohai Sea were revealed for the first time. The results showed that although consideration of the wave dependent surface wind stresses raise slightly the traditional surface wind stress, due to the accumulated effects, the computed results are improved on the whole. Storm level maximum modulation can reach 0.4 m. The results computed by the combined model agreed well with the measured data.
基金Funded by State Railway Administration Research Project(No.2023JS007)National Natural Science Foundation of China(No.52438002)+1 种基金Research and Development Programs for Science and Technology of China Railways Corporation(No.J2023G003)New Cornerstone Science Foundation through the XPLORER PRIZE。
文摘To investigate the influence of coarse aggregate parent rock properties on the elastic modulus of concrete,the mineralogical properties and stress-strain curves of granite and dolomite parent rocks,as well as the strength and elastic modulus of mortar and concrete prepared with mechanism aggregates of the corresponding lithology,and the stress-strain curves of concrete were investigated.In this paper,a coarse aggregate and mortar matrix bonding assumption is proposed,and a prediction model for the elastic modulus of mortar is established by considering the lithology of the mechanism sand and the slurry components.An equivalent coarse aggregate elastic modulus model was established by considering factors such as coarse aggregate particle size,volume fraction,and mortar thickness between coarse aggregates.Based on the elastic modulus of the equivalent coarse aggregate and the remaining mortar,a prediction model for the elastic modulus of the two and three components of concrete in series and then in parallel was established,and the predicted values differed from the measured values within 10%.It is proposed that the coarse aggregate elastic modulus in highstrength concrete is the most critical factor affecting the elastic modulus of concrete,and as the coarse aggregate elastic modulus increases by 27.7%,the concrete elastic modulus increases by 19.5%.
基金financial support from the National Natural Science Foundation of China(No.51904324,51974348,U19B6003)
文摘In recent years,supercritical CO_(2)flooding has become an effective method for developing lowpermeability reservoirs.In supercritical CO_(2)flooding different factors influence the mechanism of its displacement process for oil recovery.Asynchronous injection-production modes can use supercritical CO_(2)to enhance oil recovery but may also worsen the injection capacity.Cores with high permeability have higher oil recovery rates and better injection capacity,however,gas channeling occurs.Supercritical CO_(2)flooding has a higher oil recovery at high pressure levels,which delays the occurrence of gas channeling.Conversely,gas injection has lower displacement efficiency but better injection capacity at the high water cut stage.This study analyzes the displacement characteristics of supercritical CO_(2)flooding with a series of experiments under different injection and production parameters.Experimental results show that the gas breakthrough stage has the fastest oil production and the supercritical CO_(2)injection capacity variation tendency is closely related to the gas-oil ratio.Further experiments show that higher injection rates represent significant ultimate oil recovery and injection index,providing a good reference for developing low-permeability reservoirs.
基金supported by the grants from the Outstanding Academic Leaders Plan of Shanghai [Grant No.2018BR07]the National Science Foundation of China [Grant No.81572061]+1 种基金Program for Young Medical Technicians(Clinical Examination)in Shanghai [2016]05Shanghai Health and Family Planning Commission Clinical Research Project for Health Industry [Grant No.20184Y0199]
文摘The development of cancer is a complex process that requires the participation of many factors,including mutations in genes, regulation of signaling pathways, disruption of homeostasis, and failure of self-monitoring mechanisms. Sufficient evidence has
基金the State Key Laboratory of Coal Resources and Safe Mining,China University of Mining and Technology(No.SKLCRSM22KF011)the National Natural Science Foundation of China(Nos.52130411,52104191,51974120,and 51904103)+1 种基金the Natural Science Foundation of Hunan Province(No.2021JJ40204)the Science and Technology Innovation Program of Hunan Province(No.2020RC3047).
文摘The study of pressure stimulated current(PSC)changes of rocks is significant to monitor dynamic disasters in mines and rock masses.The existing studies focus on change laws and mechanism of currents generated under the loading of rocks.An electrical and mechanics test system was established in this paper to explore the impacts of loading rates on PSCs.The results indicated that PSC curves of different rocks had different change laws under low/high loading rates.When the loading rate was relatively low,PSC curves firstly changed gently and then increased exponentially.Under high loading rates,PSC curves experienced the rapid increase stage,gentle increase stage and sudden change stage.The compressive strength could greatly affect the peak PSC in case of rock failure.The loading rate was a key factor in average PSC.Under low loading rates,the variations of PSCs conformed to the damage charge model of fracture mechanics,while they did not at the fracture moment.Under high loading rates,the PSCs at low stress didn’t fit the model due to the stress impact effects.The experimental results could provide theoretical basis for the influence of loading rates on PSCs.
基金Supported by Special Item of Public Welfare Industry (Meteorology)Science Research (GYHY201106006)Special Item of Forecaster of China Meteorological Administration (CMATG2007Y08)Key Topics of Shandong Meteorological Bureau (2010sdqxz10)
文摘[Objective] The research aimed to study the possible mechanism of terrain effect on cold-flow snowstorm.[Method] By using the meso-scale numerical model(WRF),a cold-flow snowstorm weather process in Shandong Peninsula was carried out numerical simulation and terrain sensitivity contrast test.The possible reason of terrain effect on falling zone and strength of snowstorm was deeply analyzed from water vapor,thermodynamic field and so on.[Result] The mountain terrain in Shandong Peninsula had great influences on falling zone and strength of cold-flow snowstorm.The strength of snowstorm obviously increased,and the snowfall center obviously moved northward.The main reason was that terrain caused the low-level wind field convergence and vertical movement in the troposphere strengthened.Then,the spatial distribution of water vapor and snow water content in the cold-flow snowstorm process obviously changed.So,the whole snowstorm process was affected.[Conclusion] The mountain terrain in Shandong Peninsula was the important element which needed to be focused on considering in the forecast analysis of cold-flow snowstorm weather process.
基金Supported by the Youth Science Foundation of Shanxi Province under Grant No 2013021010-3the National Natural Science Foundation of China under Grant Nos 61434002 and 11404202
文摘Effect of mechanical stress on magnetic properties of an exchange-biased ferromagnetic/antiferromagnetic bilayer deposited on a flexible substrate is investigated. The hysteresis loops with different magnitudes and orientations of the stress can be classified into three types. The corresponding physical conditions for each type of the loop are deduced based on the principle of minimal energy. The equation of the critical stress is derived, which can judge whether the loops show hysteresis or not. Numerical calculations suggest that except for the magnitude of the mechanical stress, the relative orientation of the stress is also an important factor to tune the exchange bias effect.
文摘In this paper, the relation between Asian summer monsoon circulation and sea surface temperature anomalies over equatorial central-eastern Pacific is investigated by using a global spectral model. This model has nine layers in the vertical and the model variables are represented in the horizontal as truncated expansions of the surface spherical harmonics with rhomboidal truncation at wave number 15. The model involves comparatively complete physical processes and parameterizations with mountains.Using the above model, two experimental schemes are designed, namely control case and anomalous sea surface temperature case. The above two schemes are respectively integrated for forty days and the simulated results are obtained from the last 30-day averaged simulations.The simulations show that positive SST anomalies over equatorial central-eastern Pacific weakens Indian monsoon circulation,decreases precipitation in Indian sub-continent whereas it intensifies East Asian monsoon circulation and increases precipitation in East Asian area. All these results reflect the characteristics of Asian summer monsoon during the El Nino period. In this paper, SST anomalies over equatorial central-eastern Pacific have a direct influence on the intensity and position of subtropical high via the wave train over Northern Hemisphere, which is similar to that suggested by Nitta(1987) and the wave train over Southern Hemisphere has an influence on the intensity of Muscarene high and Australia high resulting in affecting cross equatorial flow. As a result, atmospheric interior heat sources and sinks are redistributed because of the change of cross equatorial flow. And the response of atmosphere to the new heat source and sink has a significant influence on Asian summer monsoon.
基金Supported by Teaching and Research Project of Tibet Autonomous Region Education Department(XZJYKTJX18,XZJKY19417)Quality Engineering Project(5333219008)。
文摘On the basis of combing domestic and foreign related literature and research practice,the influence mechanism of the construction of new liberal arts was analyzed,and the fundamental tasks of the construction of new liberal arts in Tibet were summarized.Based on 173 field questionnaires in Tibet,factor analysis was used to conduct empirical analysis.It is found that the cumulative contribution of the first,second,third and fourth common factor was 24.921%,21.742%,17.331%,and 14.206%,respectively.Professional orientation,the reform of talent training mode,teacher ability,quality and level of the teaching team,curriculum system reform,teaching content reform,education training service,and other evaluation indicators are the key points of the construction of new liberal arts.The research conclusion is that the construction of new liberal arts needs to highlight the"three positions";it is needed to plan and promote various resources to focus on the ability and level of professional teachers’social services;the managers and professional teachers should be the leaders and participants of the innovation of the talent training model respectively.Finally,relevant policy recommendations were put forward.
文摘This paper deals with the characteristics of silicon modification with lanthanum of Al-Si eutectic alloy in sand mold and metal mold with optical microscopy,scanning electron microscopy,electron microprobe and X-ray diffractometer.It is found that the amount of lanthanum,liquid alloy condition,holding time and stir- ring liquid influence the modification of silicon.The modification of silicon with lanthanum is of long effectiveness and has a“incubation time”.The modification can improve the ductility(δ_s)and tensile strength (σ_b)of the alloy,but their maximum values are not corresponding to the same amount of lanthanum.
文摘With the economic development and multicultural exchange of ethnic villages,more and more ethnic villages have embarked on the road of tourism to become rich,but also brought the problem of ecological pollution.Few existing literatures discuss how to alleviate the ecological pollution in ethnic villages from the perspective of tourists’environmentally responsible behavior.In the context of ethnic villages,from the perspective of integration and the attitude-context-behavior theory,this paper constructs an EV-ABC-TERB model with four variables,namely environmental attitude,local atmosphere,emotional experience and tourists’environmentally responsible behavior,to explore the characteristics,influencing factors and influencing mechanism of tourists’environmental responsibility behavior in ethnic villages.Taking Xijiang Hmong Village as the research case,questionnaire survey method and structural equation model method were used.The results show that environmental attitude positively affects emotional experience and tourists’environmentally responsible behavior.Local atmosphere positively influences tourists’environmentally responsible behavior.Emotional experience negatively affects tourists’environmentally responsible behavior and plays an intermediary role in the way that environmental attitudes affect tourists’environmentally responsible behavior.The influence of environmental attitude on emotional experience is negatively regulated by local atmosphere.Finally,based on the analysis conclusion,it provides new ideas and inspiration for the sustainable development of the ethnic village tourism.
文摘With the rapid development of China’s economy,the coordinated development of resident income and GDP has become an important indicator to measure local economic development.How to realize the synergistic growth of the two in the new era is of great significance for promoting the sustainable development of the local economy.Based on the theory of the coordinated development of resident income and GDP,this paper will take Shandong Province as an example to analyze the interaction between resident income growth and GDP,find out the influencing factors that restrict the coordinated development of resident income and GDP,and explore the impact of the coordinated development of resident income and GDP on local economic development.Finally,relevant policies will be studied.How to effectively increase residents’income,promote the sustainable and healthy development of the local economy,and put forward relevant suggestions to promote the coordinated development of residents’income and GDP.
基金supported by the National Natural Science Foundation of China(52103342 and 22209032)the Scientific Research Fund of Zhejiang Provincial Education Department(Y202456353)。
文摘High entropy materials(HEMs)show great potential as electrocatalysts for oxygen evolution reaction(OER)thanks to their interesting four-core effect.This paper presents the first systematic summary of the key factors in the synthetic methods and their influence on the structure and OER properties of HEMs(including complexing agent,synthetic temperature,and calcination atmosphere).Optimizing the components of high entropy alloys and compounds by introducing heteroatoms(such as O,S,P,N,C,and B)can enhance the chemical configurations of active sites and thus enhance the intrinsic OER kinetics.In addition,this paper emphasizes the importance of the electrocatalytic influence mechanism of the four-core effects(including the high entropy effect,lattice distortion effect,cocktail effect and sluggish diffusion effect)on catalyst structure and their OER performance.Finally,we outline the current challenges and future development directions,aiming to offer crucial insights for creating economical and efficient HEM-based electrocatalysts in the OER field.
基金supported by the National Natural Science Foundation of China(22179089)。
文摘Throughout versatile metal compositions and unique structural characteristics,polynary metal atom catalysts(PACs)readily harness synergistic intermetallic effects,significantly boosting the catalytic performances.These catalysts are featured by favorable catalytic activity,stability and selectivity,offering avenues to tackle challenges in energy conversion,environmental protection and chemical synthesis.Nevertheless,an in-depth understanding and comprehensive summary of the structure-performance relationship for the emerging PACs remains elusive.This review embarks from the classification of PACs,delving further into the origins of catalytic activity and mechanisms underpinning performance enhancement.At the beginning,it outlines the fundamental concepts,preparation methods and accurate recognition of PACs.Subsequently,it centers on discussing the origins of activity,strategies for performance optimization,mechanisms of action,and application scenarios across diverse catalytic reactions.Moreover,the unexplored issues and future perspectives of PACs are proposed at the end,stating their pivotal roles in advancing green chemistry and the sustainable energy realm.This review overall aims to provide valuable insight and guidance for the preparation and application of PACs.
基金The financial support from the National Natural Science Foundation of China(Grant Nos.41941018 and 52074299)the Fundamental Research Funds for the Central Universities of China(Grant No.2023JCCXSB02)。
文摘Rockburst are often encountered in tunnel construction due to the complex geological conditions.To study the influence of unloading rate on rockburst,gneiss rockburst experiments were conducted under three groups of unloading rates.A high-speed photography system and acoustic emission(AE)system were used to monitor the entire process of rockburst process in real-time.The results show that the intensity of gneiss rockburst decreases with decrease of unloading rate,which is manifested as the reduction of AE energy and fragments ejection velocity.The mechanisms are proposed to explain this effect:(i)The reduction of unloading rate changes the crack propagation mechanism in the process of rockburst.This makes the rockbursts change from the tensile failure mechanism at high unloading rate to the tension-shear mixed failure mechanism at low unloading rate,and more energy released in the form of shear crack propagation.Then,less strain energy is converted into kinetic energy of fragments ejection.(ii)Less plate cracking degree of gneiss has taken shape due to decrease of unloading rate,resulting in the destruction of rockburst incubation process.The enlightenments of reducing the unloading rate for the project are also described quantitatively.The rockburst magnitude is reduced from the medium magnitude at the unloading rate of 0.1 MPa/s to the slight magnitude at the unloading rate of 0.025 MPa/s,which was judged by the ejection velocity.
基金funded by the National Forestry and Grassland Administration(Grant No.2023132050)National Forestry and Grassland Administration(Grant No.2019132703)+1 种基金National Science Foundation of China(Grants No.42171093,42101250)Fengyun 3 Satellite Ground Application Project(Grants No.FY-2(03)-AS-12.09-ZT,FY-APP-2021.0407)。
文摘Urbanization significantly affects the balance of key elements such as water,heat,and carbon in cities.However,previous studies have not integrated these factors for comprehensive analysis.Here,we proposed a waterheat-carbon(WHC)nexus model to provide a holistic understanding of urbanization's impacts.Furthermore,we employed the model to identify the mechanisms and response thresholds of urbanization through this coupling approach.Our findings reveal three key insights:(1)WHC exhibits a nonlinear,inverted S-shaped response to urbanization.(2)The mechanisms through which urbanization impacts WHC differ significantly across urbanization gradients.Acrossing urbanization gradients,the complexity of impact pathways increases,with direct effects becoming more pronounced and positive impact pathways emerging progressively.(3)We identified priority zones for restoration and protection based on the likelihood of units shifting between lower-risk and higher-risk categories.Our study enhances understanding of the WHC-urbanization nexus and highlights the importance of accounting for threshold effects and environmental interactions when examining the impact between urbanization and WHC.This framework can be adapted to other urban areas experiencing similar challenges.
基金the“High-quality Development,Credit Assets,and Digital Economy”project(KY2023E0122)funded by the Beijing Academy of Social Sciencesthe Sichuan Philosophy and Social Science Planning project(SC21B0310)+2 种基金a technological innovation capacity building program(KTYTD202233)a college students’innovation and entrepreneurship program(202310621238,202310621243)supported by Chengdu University of Information Technology.
文摘Digital village construction opens a new vista for fulfilling consumption capabilities and optimizing consumption patterns in rural areas.For this research,we used the microdata on rural households from the 2019 China Household Finance Survey(CHFS)to conduct an empirical examination of the impact of digital village construction on the upgrading of rural household consumption and its possible influence mechanisms in the endogenous switching regression(ESR)model.Our research findings can be summarized in three points.First,digital village construction has significantly contributed positive contributions to the improvements and upgrading of rural household consumption.Second,digital village construction can help upgrade rural household consumption by increasing their participation in online shopping and expanding online shopping channels.Third,digital village construction means different things to rural households at different levels of risk exposure,with its facilitation to consumption upgrades in proportion to income risks facing rural households.Our research findings,which came from an extensive,in-depth exploration of the factors influencing rural household consumption,are of practical significance and policy value to the stimulating and fulfilling of consumption potentials among rural households.
基金National Natural Science Foundation of China, No. 41401190 No.41130748 No.41101165
文摘Based on multiple remote-sensing image interpretation and classification, and economic and social data, this study focused on rural settlement and land use change amidst rapid urbanization. Rural settlements, spatial and temporal patterns of land use and influ- encing factors in the Bohai Rim were explored within 5x5 km grid cells, as per GIS spatial analysis and geostatistical analysis. Results show that the spatial distribution of rural settle- ments in the Bohai Rim is remarkably varied. The number of rural settlement sites in a 5x5 km grid cell exceeding 5.0 are distributed in a six-area pattern in the Bohai Rim; rural settlement dispersion is particularly high in agricultural regions in south Hebei and southwest Shandong, suggesting rural settlement density keeps increasing from northeast to southwest, charac- terized by high density and dispersed spatial distribution in traditional agricultural regions. Furthermore, rural settlements show dramatic spatial differences in terms of distribution and dynamic change degrees in the Bohai Rim. In terms of spatial distribution, rural residential land is always extensive in plains, with a high density of rural settlements, on the North China Plain in particular, and rural residential land in the south of Shandong province is also exten- sive, with most rural settlement land use areas in the 5x5 km grid cells exceeding 3 km2. However, traditional agricultural regions have underdeveloped economies, industrialization and tertiary industries, characterized by low urbanization rates, with farmers not feeling as- similated in rural or urban areas. In terms of the temporal sequence, urban expansion rapidly promotes the transformation of rural residential lands in rural-urban transitional belts of pro- vincial capital or prefecture-level city into urban lands, and in traditional rural areas, residen- tial lands are growing. The natural environment, transportation conditions, economic devel- opment and farmers＇ incomes all have effects on type of land use change and pattern of rural settlements. It is a core objective for future rural development to reconstruct a rational spatial pattern of villages or towns and well-organized village-town systems, build central villages, key towns or central towns, optimize or reconstruct production, living and eco-space of rural areas. It is of significance for rural geographical research to further interpret and explore spatial reconstruction theory.
