Reducing water consumption in rice production in China without affecting grain yield and quality is a significant challenge.This study explored how various dry cultivation methods could improve rice quality while bala...Reducing water consumption in rice production in China without affecting grain yield and quality is a significant challenge.This study explored how various dry cultivation methods could improve rice quality while balancing yield to maintain sustainable rice production.A japonica upland rice cultivar and a japonica paddy rice cultivar were cultivated in the field with three cultivation methods:plastic film mulching dry cultivation(PFMC),bare dry cultivation(BC),and continuous flooding cultivation(CF)as control.There was no significant difference in upland rice yield between PFMC and BC,nor in paddy rice yield between PFMC and CF.Compared with CF,the two varieties'yields decreased significantly with BC.Dry cultivation,especially PFMC,could decrease the active filling period,chalky rice rate,chalkiness,amylose content,gel consistency,breakdown viscosity,the ratio of glutelin to prolamin,and leaf senescence while increasing water use efficiency,protein components content,setback viscosity,grain starch branching enzyme(Q-enzyme)activity,and average filling rate.Compared with paddy rice,upland rice had a lower yield,shorter active filling period,lower chalkiness grain rate and gel consistency,higher amylose content,breakdown viscosity,protein components content,and average filling rate.Grain Q-enzyme activity and grain-filling parameters were closely related to rice quality.Reasonable dry cultivation methods could balance yield and quality,especially by improving rice's nutritional and appearance quality.展开更多
Ni-based electrocatalysts are considered a promising choice for urea-assisted hydrogen production.However,its application remains challenging owing to the high occupancy of d orbital at the Ni site,which suppresses th...Ni-based electrocatalysts are considered a promising choice for urea-assisted hydrogen production.However,its application remains challenging owing to the high occupancy of d orbital at the Ni site,which suppresses the reactant adsorption to achieve satisfactory urea oxidation reaction(UOR)and hydrogen evolution reaction(HER)activity.Herein,the WO_(3) site with empty d orbital is introduced into Ni_(3)S_(2) to construct dual active sites for regulating the adsorption of reactive molecules.Experimental and theoretical calculations indicate that the electron transfer from Ni_(3)S_(2) to WO_(3) forms electron-deficient Ni with sufficient empty d orbitals for optimizing urea/H_(2)O adsorption and tuning the adsorption behavior of the amino and carbonyl groups in urea.Consequently,the Ni_(3)S_(2)-WO_(3)/NF presents a remarkably low potential of 1.38 V to reach 10 mA cm^(-2) for UOR-assisted HER.This work highlights the significance of constructing synergistic dual active sites toward developing advanced catalysts for urea-assisted hydrogen production.展开更多
NiMo catalyst exhibits excellent catalytic performance in the electrooxidation of 5-hydroxymethylfurfural(HMF)to produce high-value 2,5-furandicarboxylic acid(FDCA).Although metallic nickel is known to undergo reconst...NiMo catalyst exhibits excellent catalytic performance in the electrooxidation of 5-hydroxymethylfurfural(HMF)to produce high-value 2,5-furandicarboxylic acid(FDCA).Although metallic nickel is known to undergo reconstruction into high-valent species during the reaction,the dynamic evolution of molybdenum components in NiMo catalyst and their mechanistic roles in catalytic reaction remain unclear.In this study,the structural evolution of NiMo alloy during HMF electrooxidation is systematically investigated.Operando analyses reveal that under anodic polarization,molybdenum undergoes oxidative dissolution in the form of MoO_(4)^(2-),concurrently driving the generation of high-valent Ni^(3+)species.Meanwhile,the dissolved MoO_(4)^(2-)re-adsorbs on the catalyst surface,forming a unique interfacial structure with Ni^(3+).Electrochemical results demonstrate that this surface structure facilitates a synergistic effect between the MoO_(4)^(2-)and high-valent Ni^(3+),enhancing the adsorption and activation of HMF molecules.Therefore,the NiMo alloy exhibits excellent catalytic performance,with a high FDCA selectivity of 99.0%.This study provides new insights into the relationship between the catalyst reconstruction process and enhancement of catalytic performance.展开更多
In the current trend of educational digitization,online learning platforms have proliferated,making the visual design of digital learning resources increasingly critical.However,existing visual designs for online lear...In the current trend of educational digitization,online learning platforms have proliferated,making the visual design of digital learning resources increasingly critical.However,existing visual designs for online learning resources face numerous challenges.The emergence of AIGC(Artificial Intelligence-Generated Content)technology offers innovative solutions to these issues.This paper explores the application of AIGC technology in enhancing the“new quality productive forces”of visual design for online learning resources.It emphasizes the need to balance technological innovation with humanistic care and highlights the importance of human intervention in the design process.展开更多
5-Hydroxymethylfurfural electrooxidation reaction(HMFOR)provides a promising route for producing highvalue-added compounds.It is generally believed that NiOOH is the active species in HMFOR process,but its inherently ...5-Hydroxymethylfurfural electrooxidation reaction(HMFOR)provides a promising route for producing highvalue-added compounds.It is generally believed that NiOOH is the active species in HMFOR process,but its inherently poor electron transfer ability leads to limited catalytic activity.In this work,a W doping strategy is adopted to regulate the electron transfer between NiOOH and reaction molecules.Electrochemical results show that W-doped Ni_(5)P_(4)-R exhibits excellent electrochemical performance for the oxidation of HMF to FDCA with the conversion of HMF and yield of FDCA both close to~100%.Density functional theory and in-situ characterization reveal that the introduction of W causes the distortion of NiOOH lattice,resulting in the Jahn-Teller distortion and the elimination of orbital degeneracy,thereby broadening the e_(g)^(*)band of NiOOH.This feature is beneficial for the electron transfer between W-doped NiOOH and HMF(1.31 e^(-)),thereby promoting the C–H bond activation of the aldehyde group in HMF and effectively reducing the energy barrier of rate-determining step(RDS).展开更多
Aging and regeneration represent complex biological phenomena that have long captivated the scientific community.To fully comprehend these processes,it is essential to investigate molecular dynamics through a lens tha...Aging and regeneration represent complex biological phenomena that have long captivated the scientific community.To fully comprehend these processes,it is essential to investigate molecular dynamics through a lens that encompasses both spatial and temporal dimensions.Conventional omics methodologies,such as genomics and transcriptomics,have been instrumental in identifying critical molecular facets of aging and regeneration.However,these methods are somewhat limited,constrained by their spatial resolution and their lack of capacity to dynamically represent tissue alterations.The advent of emerging spatiotemporal multi-omics approaches,encompassing transcriptomics,proteomics,metabolomics,and epigenomics,furnishes comprehensive insights into these intricate molecular dynamics.These sophisticated techniques facilitate accurate delineation of molecular patterns across an array of cells,tissues,and organs,thereby offering an in-depth understanding of the fundamental mechanisms at play.This review meticulously examines the significance of spatiotemporal multi-omics in the realms of aging and regeneration research.It underscores how these methodologies augment our comprehension of molecular dynamics,cellular interactions,and signaling pathways.Initially,the review delineates the foundational principles underpinning these methods,followed by an evaluation of their recent applications within the field.The review ultimately concludes by addressing the prevailing challenges and projecting future advancements in the field.Indubitably,spatiotemporal multi-omics are instrumental in deciphering the complexities inherent in aging and regeneration,thus charting a course toward potential therapeutic innovations.展开更多
Building Information Modelling(BIM)technology can solve construction issues from multiple perspectives,including technical and managerial.While existing research has primarily focused on BIM’s benefits and framework ...Building Information Modelling(BIM)technology can solve construction issues from multiple perspectives,including technical and managerial.While existing research has primarily focused on BIM’s benefits and framework development,few studies discussed whether BIM can be successfully applied in developing countries.This paper examines the current status and key obstacles hindering BIM adoption in developing countries,analyzing their underlying causes.Notably,the study reveals that high BIM awareness does not directly lead to high BIM usage.The findings aim to provide theoretical support for enhancing the BIM environment and increasing implementation feasibility in developing countries.Additionally,the research identifies critical barriers for governments to address in promoting BIM adoption,offering a foundation for policy formulation.展开更多
Hyperparameters are important for machine learning algorithms since they directly control the behaviors of training algorithms and have a significant effect on the performance of machine learning models. Several techn...Hyperparameters are important for machine learning algorithms since they directly control the behaviors of training algorithms and have a significant effect on the performance of machine learning models. Several techniques have been developed and successfully applied for certain application domains. However, this work demands professional knowledge and expert experience. And sometimes it has to resort to the brute-force search.Therefore, if an efficient hyperparameter optimization algorithm can be developed to optimize any given machine learning method, it will greatly improve the efficiency of machine learning. In this paper, we consider building the relationship between the performance of the machine learning models and their hyperparameters by Gaussian processes. In this way, the hyperparameter tuning problem can be abstracted as an optimization problem and Bayesian optimization is used to solve the problem. Bayesian optimization is based on the Bayesian theorem. It sets a prior over the optimization function and gathers the information from the previous sample to update the posterior of the optimization function. A utility function selects the next sample point to maximize the optimization function.Several experiments were conducted on standard test datasets. Experiment results show that the proposed method can find the best hyperparameters for the widely used machine learning models, such as the random forest algorithm and the neural networks, even multi-grained cascade forest under the consideration of time cost.展开更多
This paper reports a comprehensive study on the observed and projected spatiotemporal changes in mean and extreme climate over the arid region of northwestern China, based on gridded observation data and CMIP5 simulat...This paper reports a comprehensive study on the observed and projected spatiotemporal changes in mean and extreme climate over the arid region of northwestern China, based on gridded observation data and CMIP5 simulations under the RCP4.5 and RCP8.5 scenarios. The observational results reveal an increase in annual mean temperature since 1961, largely attributable to the increase in minimum temperature. The annual mean precipitation also exhibits a significant increasing tendency. The precipitation amount in the most recent decade was greater than in any preceding decade since 1961. Seasonally, the greatest increase in temperature and precipitation appears in winter and in summer, respectively. Widespread significant changes in temperature-related extremes are consistent with warming, with decreases in cold extremes and increases in warm extremes. The warming of the coldest night is greater than that of the warmest day, and changes in cold and warm nights are more evident than for cold and warm days. Extreme precipitation and wet days exhibit an increasing trend, and the maximum number of consecutive dry days shows a tendency toward shorter duration. Multi-model ensemble mean projections indicate an overall continual increase in temperature and precipitation during the 21 st century. Decreases in cold extremes, increases in warm extremes, intensification of extreme precipitation, increases in wet days, and decreases in consecutive dry days, are expected under both emissions scenarios, with larger changes corresponding to stronger radiative forcing.展开更多
A PbO2/Sb-SnO2/TiO2 nanotube array composite electrode was successfully synthesized and its electrochemical oxidation properties were investigated.Field-emission scanning electron microscopy(FE-SEM)and X-ray diffracti...A PbO2/Sb-SnO2/TiO2 nanotube array composite electrode was successfully synthesized and its electrochemical oxidation properties were investigated.Field-emission scanning electron microscopy(FE-SEM)and X-ray diffraction(XRD)results showed that the PbO2 coating was composed of anα-PbO2 inner layer and aβ-PbO2 outer layer.Accelerated life measurement indicated that the composite electrode had a lifetime of 815 h.Rhodamine B(RhB)was employed as a model pollutant to analyze the electrocatalytic activity of the electrode.The effects of initial RhB concentration,current density,initial pH,temperature,and chloride ion concentration on the electrochemical oxidation were investigated in detail.Inductively coupled plasma atomic emission spectroscopy(ICP-AES)results suggested that the concentration of leached Pb^2+in the electrolyte during the electrocatalytic oxidation process can be neglected.Finally,the degradation mechanism during the electrocatalytic oxidation process was proposed based on the results of solid-phase micro-extraction-gas chromatography-mass spectrometry(SPME-GC-MS).The high electrocatalytic performance of the composite electrode makes it a promising anode for the treatment of organic pollutants in aqueous solution.展开更多
The ongoing coronavirus disease 2019(COVID-19)pandemic caused more than 96 million infections and over 2 million deaths worldwide so far.However,there is no approved vaccine available for severe acute respiratory synd...The ongoing coronavirus disease 2019(COVID-19)pandemic caused more than 96 million infections and over 2 million deaths worldwide so far.However,there is no approved vaccine available for severe acute respiratory syndrome coronavirus 2(SARS-CoV-2),the disease causative agent.Vaccine is the most effective approach to eradicate a pathogen.The tests of safety and efficacy in animals are pivotal for developing a vaccine and before the vaccine is applied to human populations.Here we evaluated the safety,immunogenicity,and efficacy of an inactivated vaccine based on the whole viral particles in human ACE2 transgenic mouse and in non-human primates.Our data showed that the inactivated vaccine successfully induced SARS-CoV-2-specific neutralizing antibodies in mice and non-human primates,and subsequently provided partial(in low dose)or full(in high dose)protection of challenge in the tested animals.In addition,passive serum transferred from vaccine-immunized mice could also provide full protection from SARS-CoV-2 infection in mice.These results warranted positive outcomes in future clinical trials in humans.展开更多
A long-term simulation for the period 1990–2010 is conducted with the latest version of the International Centre for Theoretical Physics＇ Regional Climate Model（RegCM4）, driven by ERA-Interim boundary conditions a...A long-term simulation for the period 1990–2010 is conducted with the latest version of the International Centre for Theoretical Physics＇ Regional Climate Model（RegCM4）, driven by ERA-Interim boundary conditions at a grid spacing of 25 km. The Community Land Model（CLM） is used to describe land surface processes, with updates in the surface parameters,including the land cover and surface emissivity. The simulation is compared against observations to evaluate the model performance in reproducing the present day climatology and interannual variability over the 10 main river basins in China,with focus on surface air temperature and precipitation. Temperature and precipitation from the ERA-Interim reanalysis are also considered in the model assessment. Results show that the model reproduces the present day climatology over China and its main river basins, with better performances in June–July–August compared to December–January–February（DJF）.In DJF, we find a warm bias at high latitudes, underestimated precipitation in the south, and overestimated precipitation in the north. The model in general captures the observed interannual variability, with greater skill for temperature. We also find an underestimation of heavy precipitation events in eastern China, and an underestimation of consecutive dry days in northern China and the Tibetan Plateau. Similar biases for both mean climatology and extremes are found in the ERA-Interim reanalysis, indicating the difficulties for climate models in simulating extreme monsoon climate events over East Asia.展开更多
Combined radiation-wound injury(CRWI) is characterized by blood vessel damage and pro-inflammatory cytokine deficiency. Studies have identified that the direct application of leptin plays a significant role in angioge...Combined radiation-wound injury(CRWI) is characterized by blood vessel damage and pro-inflammatory cytokine deficiency. Studies have identified that the direct application of leptin plays a significant role in angiogenesis and inflammation. We established a sustained and stable leptin expression system to study the mechanism. A lentivirus method was employed to explore the angiogenic potential and peripheral inflammation of irradiated human umbilical vein endothelial cells(HUVECs). Leptin was transfected into human placenta-derived mesenchymal stem cells(HPMSCs) with lentiviral vectors. HUVECs were irradiated by X-ray at a single dose of 20 Gy. Transwell migration assay was performed to assess the migration of irradiated HUVECs. Based on the Transwell systems, co-culture systems of HPMSCs and irradiated HUVECs were established. Cell proliferation was measured by cell counting kit-8(CCK-8) assay. The secretion of pro-inflammatory cytokines(human granulocyte macrophage-colony stimulating factor(GM-CSF), interleukin(IL)-1α, IL-6, and IL-8) was detected by enzyme-linked immunosorbent assay(ELISA). The expression of pro-angiogenic factors(vascular endothelial growth factor(VEGF) and basic fibroblast growth factor(b FGF)) mRNA was detected by real-time quantitative polymerase chain reaction(RT-qPCR) assay. Relevant molecules of the nuclear factor-κB(NF-κB) and Janus kinase(JAK)/signal transducer and activator of transcription(STAT) signaling pathways were detected by western blot assay. Results showed that leptin-modified HPMSCs(HPMSCs/leptin) exhibited better cell proliferation, migration, and angiogenic potential(expressed more VEGF and bFGF). In both the single HPMSCs/leptin and the co-culture systems of HPMSCs/leptin and irradiated HUVECs, the increased secretion of pro-inflammatory cytokines(human GM-CSF, IL-1α, and IL-6) was associated with the interaction of the NF-κB and JAK/STAT signaling pathways. We conclude that HPMSCs/leptin could promote angiogenic potential and peripheral inflammation of HUVECs after X-ray radiation.展开更多
5-Hydroxymethylfurfural electrooxidation reaction(HMFOR)is a promising route to produce valueadded chemicals from biomass.Since it involves HMF adsorption and C-H/O-H cleavage,understanding the adsorption behavior and...5-Hydroxymethylfurfural electrooxidation reaction(HMFOR)is a promising route to produce valueadded chemicals from biomass.Since it involves HMF adsorption and C-H/O-H cleavage,understanding the adsorption behavior and catalytic process of organic molecules on catalysts is important.Herein,the selective adsorption sites of NiMoO are tuned by Ni particles for HMFOR-assisted H2production.Experimental and theoretical calculation results indicate that the synergistic interaction between Ni and NiMoO optimizes the adsorption/desorption of HMF/intermediates/2,5-furandicarboxylic acid(FDCA)and promotes the C-H/O-H bond cleavage,thereby improving the HMFOR kinetics(kNiMoO-Ni/kNiMoO=1.97)and FDCA selectivity(99.3%).When coupled as a two-electrode system,it can drive efficient HMF conversion(FDCA yield:98.5%)and H2production(Faradaic efficiency:99.1%)at 1.45 V.This work thus offers a strategy to tune the adsorption sites of catalyst for efficient HMFOR-assisted H2production.展开更多
基金he National Key Research and Development Program of China(2022YFD2300304)the National Natural Science Foundation of China(31671617)a project funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD),China。
文摘Reducing water consumption in rice production in China without affecting grain yield and quality is a significant challenge.This study explored how various dry cultivation methods could improve rice quality while balancing yield to maintain sustainable rice production.A japonica upland rice cultivar and a japonica paddy rice cultivar were cultivated in the field with three cultivation methods:plastic film mulching dry cultivation(PFMC),bare dry cultivation(BC),and continuous flooding cultivation(CF)as control.There was no significant difference in upland rice yield between PFMC and BC,nor in paddy rice yield between PFMC and CF.Compared with CF,the two varieties'yields decreased significantly with BC.Dry cultivation,especially PFMC,could decrease the active filling period,chalky rice rate,chalkiness,amylose content,gel consistency,breakdown viscosity,the ratio of glutelin to prolamin,and leaf senescence while increasing water use efficiency,protein components content,setback viscosity,grain starch branching enzyme(Q-enzyme)activity,and average filling rate.Compared with paddy rice,upland rice had a lower yield,shorter active filling period,lower chalkiness grain rate and gel consistency,higher amylose content,breakdown viscosity,protein components content,and average filling rate.Grain Q-enzyme activity and grain-filling parameters were closely related to rice quality.Reasonable dry cultivation methods could balance yield and quality,especially by improving rice's nutritional and appearance quality.
基金supported by the National Natural Science Foundation of China(22162004)the Natural Science Foundation of Guangxi Province(2022JJD120011).
文摘Ni-based electrocatalysts are considered a promising choice for urea-assisted hydrogen production.However,its application remains challenging owing to the high occupancy of d orbital at the Ni site,which suppresses the reactant adsorption to achieve satisfactory urea oxidation reaction(UOR)and hydrogen evolution reaction(HER)activity.Herein,the WO_(3) site with empty d orbital is introduced into Ni_(3)S_(2) to construct dual active sites for regulating the adsorption of reactive molecules.Experimental and theoretical calculations indicate that the electron transfer from Ni_(3)S_(2) to WO_(3) forms electron-deficient Ni with sufficient empty d orbitals for optimizing urea/H_(2)O adsorption and tuning the adsorption behavior of the amino and carbonyl groups in urea.Consequently,the Ni_(3)S_(2)-WO_(3)/NF presents a remarkably low potential of 1.38 V to reach 10 mA cm^(-2) for UOR-assisted HER.This work highlights the significance of constructing synergistic dual active sites toward developing advanced catalysts for urea-assisted hydrogen production.
基金supported by the Natural Science Foundation of Guangxi Zhuang(2022JJD120011)the National Natural Science Foundation of China(22479031,22162004)the Project for Enhancing Young and Middle-aged Teacher's Research Basis Ability in Colleges of Guangxi(2025KY0040).
文摘NiMo catalyst exhibits excellent catalytic performance in the electrooxidation of 5-hydroxymethylfurfural(HMF)to produce high-value 2,5-furandicarboxylic acid(FDCA).Although metallic nickel is known to undergo reconstruction into high-valent species during the reaction,the dynamic evolution of molybdenum components in NiMo catalyst and their mechanistic roles in catalytic reaction remain unclear.In this study,the structural evolution of NiMo alloy during HMF electrooxidation is systematically investigated.Operando analyses reveal that under anodic polarization,molybdenum undergoes oxidative dissolution in the form of MoO_(4)^(2-),concurrently driving the generation of high-valent Ni^(3+)species.Meanwhile,the dissolved MoO_(4)^(2-)re-adsorbs on the catalyst surface,forming a unique interfacial structure with Ni^(3+).Electrochemical results demonstrate that this surface structure facilitates a synergistic effect between the MoO_(4)^(2-)and high-valent Ni^(3+),enhancing the adsorption and activation of HMF molecules.Therefore,the NiMo alloy exhibits excellent catalytic performance,with a high FDCA selectivity of 99.0%.This study provides new insights into the relationship between the catalyst reconstruction process and enhancement of catalytic performance.
文摘In the current trend of educational digitization,online learning platforms have proliferated,making the visual design of digital learning resources increasingly critical.However,existing visual designs for online learning resources face numerous challenges.The emergence of AIGC(Artificial Intelligence-Generated Content)technology offers innovative solutions to these issues.This paper explores the application of AIGC technology in enhancing the“new quality productive forces”of visual design for online learning resources.It emphasizes the need to balance technological innovation with humanistic care and highlights the importance of human intervention in the design process.
基金supported by the National Natural Science Foundation of China(22479031,22162004)the Natural Science Foundation of Guangxi(2022JJD120011)the High-performance Computing Platform of Guangxi University.
文摘5-Hydroxymethylfurfural electrooxidation reaction(HMFOR)provides a promising route for producing highvalue-added compounds.It is generally believed that NiOOH is the active species in HMFOR process,but its inherently poor electron transfer ability leads to limited catalytic activity.In this work,a W doping strategy is adopted to regulate the electron transfer between NiOOH and reaction molecules.Electrochemical results show that W-doped Ni_(5)P_(4)-R exhibits excellent electrochemical performance for the oxidation of HMF to FDCA with the conversion of HMF and yield of FDCA both close to~100%.Density functional theory and in-situ characterization reveal that the introduction of W causes the distortion of NiOOH lattice,resulting in the Jahn-Teller distortion and the elimination of orbital degeneracy,thereby broadening the e_(g)^(*)band of NiOOH.This feature is beneficial for the electron transfer between W-doped NiOOH and HMF(1.31 e^(-)),thereby promoting the C–H bond activation of the aldehyde group in HMF and effectively reducing the energy barrier of rate-determining step(RDS).
基金supported by the Leading Innovative and Entrepreneur Team Introduction Program of Zhejiang(2023R01002)the National Natural Science Foundation of China(82271629,82301790)。
文摘Aging and regeneration represent complex biological phenomena that have long captivated the scientific community.To fully comprehend these processes,it is essential to investigate molecular dynamics through a lens that encompasses both spatial and temporal dimensions.Conventional omics methodologies,such as genomics and transcriptomics,have been instrumental in identifying critical molecular facets of aging and regeneration.However,these methods are somewhat limited,constrained by their spatial resolution and their lack of capacity to dynamically represent tissue alterations.The advent of emerging spatiotemporal multi-omics approaches,encompassing transcriptomics,proteomics,metabolomics,and epigenomics,furnishes comprehensive insights into these intricate molecular dynamics.These sophisticated techniques facilitate accurate delineation of molecular patterns across an array of cells,tissues,and organs,thereby offering an in-depth understanding of the fundamental mechanisms at play.This review meticulously examines the significance of spatiotemporal multi-omics in the realms of aging and regeneration research.It underscores how these methodologies augment our comprehension of molecular dynamics,cellular interactions,and signaling pathways.Initially,the review delineates the foundational principles underpinning these methods,followed by an evaluation of their recent applications within the field.The review ultimately concludes by addressing the prevailing challenges and projecting future advancements in the field.Indubitably,spatiotemporal multi-omics are instrumental in deciphering the complexities inherent in aging and regeneration,thus charting a course toward potential therapeutic innovations.
文摘Building Information Modelling(BIM)technology can solve construction issues from multiple perspectives,including technical and managerial.While existing research has primarily focused on BIM’s benefits and framework development,few studies discussed whether BIM can be successfully applied in developing countries.This paper examines the current status and key obstacles hindering BIM adoption in developing countries,analyzing their underlying causes.Notably,the study reveals that high BIM awareness does not directly lead to high BIM usage.The findings aim to provide theoretical support for enhancing the BIM environment and increasing implementation feasibility in developing countries.Additionally,the research identifies critical barriers for governments to address in promoting BIM adoption,offering a foundation for policy formulation.
基金supported in part by the National Natural Science Foundation of China under Grant No.61503059
文摘Hyperparameters are important for machine learning algorithms since they directly control the behaviors of training algorithms and have a significant effect on the performance of machine learning models. Several techniques have been developed and successfully applied for certain application domains. However, this work demands professional knowledge and expert experience. And sometimes it has to resort to the brute-force search.Therefore, if an efficient hyperparameter optimization algorithm can be developed to optimize any given machine learning method, it will greatly improve the efficiency of machine learning. In this paper, we consider building the relationship between the performance of the machine learning models and their hyperparameters by Gaussian processes. In this way, the hyperparameter tuning problem can be abstracted as an optimization problem and Bayesian optimization is used to solve the problem. Bayesian optimization is based on the Bayesian theorem. It sets a prior over the optimization function and gathers the information from the previous sample to update the posterior of the optimization function. A utility function selects the next sample point to maximize the optimization function.Several experiments were conducted on standard test datasets. Experiment results show that the proposed method can find the best hyperparameters for the widely used machine learning models, such as the random forest algorithm and the neural networks, even multi-grained cascade forest under the consideration of time cost.
基金jointly supported by the National Basic Research Program of China(Grant No.2012CB955900)the National Key Research and Development Program of China(Grant No.2016YFA0600701)the National Natural Science Foundation of China(Grant No.41675069)
文摘This paper reports a comprehensive study on the observed and projected spatiotemporal changes in mean and extreme climate over the arid region of northwestern China, based on gridded observation data and CMIP5 simulations under the RCP4.5 and RCP8.5 scenarios. The observational results reveal an increase in annual mean temperature since 1961, largely attributable to the increase in minimum temperature. The annual mean precipitation also exhibits a significant increasing tendency. The precipitation amount in the most recent decade was greater than in any preceding decade since 1961. Seasonally, the greatest increase in temperature and precipitation appears in winter and in summer, respectively. Widespread significant changes in temperature-related extremes are consistent with warming, with decreases in cold extremes and increases in warm extremes. The warming of the coldest night is greater than that of the warmest day, and changes in cold and warm nights are more evident than for cold and warm days. Extreme precipitation and wet days exhibit an increasing trend, and the maximum number of consecutive dry days shows a tendency toward shorter duration. Multi-model ensemble mean projections indicate an overall continual increase in temperature and precipitation during the 21 st century. Decreases in cold extremes, increases in warm extremes, intensification of extreme precipitation, increases in wet days, and decreases in consecutive dry days, are expected under both emissions scenarios, with larger changes corresponding to stronger radiative forcing.
基金supported by the National Natural Science Foundation of China(21507104)Natural Science Basic Research Plan in Shaanxi Province of China(2017JM2015)~~
文摘A PbO2/Sb-SnO2/TiO2 nanotube array composite electrode was successfully synthesized and its electrochemical oxidation properties were investigated.Field-emission scanning electron microscopy(FE-SEM)and X-ray diffraction(XRD)results showed that the PbO2 coating was composed of anα-PbO2 inner layer and aβ-PbO2 outer layer.Accelerated life measurement indicated that the composite electrode had a lifetime of 815 h.Rhodamine B(RhB)was employed as a model pollutant to analyze the electrocatalytic activity of the electrode.The effects of initial RhB concentration,current density,initial pH,temperature,and chloride ion concentration on the electrochemical oxidation were investigated in detail.Inductively coupled plasma atomic emission spectroscopy(ICP-AES)results suggested that the concentration of leached Pb^2+in the electrolyte during the electrocatalytic oxidation process can be neglected.Finally,the degradation mechanism during the electrocatalytic oxidation process was proposed based on the results of solid-phase micro-extraction-gas chromatography-mass spectrometry(SPME-GC-MS).The high electrocatalytic performance of the composite electrode makes it a promising anode for the treatment of organic pollutants in aqueous solution.
基金supported by the National Key R&D Program of China(2020YFC0842000 to Z.M.Yuan and 2020YFC0842100 to C.Shan)the Strategic Priority Research Program of the Chinese Academy of Sciences(XDB29010101 to Z.L.Shi)+1 种基金the China Natural Science Foundation(82041013 to P.Zhou)the Youth Innovation Promotion Association of the Chinese Academy of Sciences(CAS)(2019328 to X.L.Yang)。
文摘The ongoing coronavirus disease 2019(COVID-19)pandemic caused more than 96 million infections and over 2 million deaths worldwide so far.However,there is no approved vaccine available for severe acute respiratory syndrome coronavirus 2(SARS-CoV-2),the disease causative agent.Vaccine is the most effective approach to eradicate a pathogen.The tests of safety and efficacy in animals are pivotal for developing a vaccine and before the vaccine is applied to human populations.Here we evaluated the safety,immunogenicity,and efficacy of an inactivated vaccine based on the whole viral particles in human ACE2 transgenic mouse and in non-human primates.Our data showed that the inactivated vaccine successfully induced SARS-CoV-2-specific neutralizing antibodies in mice and non-human primates,and subsequently provided partial(in low dose)or full(in high dose)protection of challenge in the tested animals.In addition,passive serum transferred from vaccine-immunized mice could also provide full protection from SARS-CoV-2 infection in mice.These results warranted positive outcomes in future clinical trials in humans.
基金jointly supported by the National Key Research and Development Program of China(Grant No.2016YFA0600704)the National Natural Science Foundation(Grant No.41375104)the Climate Change Specific Fund of China(Grant Nos.CCSF201626 and CCSF201509)
文摘A long-term simulation for the period 1990–2010 is conducted with the latest version of the International Centre for Theoretical Physics＇ Regional Climate Model（RegCM4）, driven by ERA-Interim boundary conditions at a grid spacing of 25 km. The Community Land Model（CLM） is used to describe land surface processes, with updates in the surface parameters,including the land cover and surface emissivity. The simulation is compared against observations to evaluate the model performance in reproducing the present day climatology and interannual variability over the 10 main river basins in China,with focus on surface air temperature and precipitation. Temperature and precipitation from the ERA-Interim reanalysis are also considered in the model assessment. Results show that the model reproduces the present day climatology over China and its main river basins, with better performances in June–July–August compared to December–January–February（DJF）.In DJF, we find a warm bias at high latitudes, underestimated precipitation in the south, and overestimated precipitation in the north. The model in general captures the observed interannual variability, with greater skill for temperature. We also find an underestimation of heavy precipitation events in eastern China, and an underestimation of consecutive dry days in northern China and the Tibetan Plateau. Similar biases for both mean climatology and extremes are found in the ERA-Interim reanalysis, indicating the difficulties for climate models in simulating extreme monsoon climate events over East Asia.
基金Project supported by the Special Fund for Cooperation of Local Government and College(Schools and Institutes)in Changchun,Jilin Province(No.17DY024),China。
文摘Combined radiation-wound injury(CRWI) is characterized by blood vessel damage and pro-inflammatory cytokine deficiency. Studies have identified that the direct application of leptin plays a significant role in angiogenesis and inflammation. We established a sustained and stable leptin expression system to study the mechanism. A lentivirus method was employed to explore the angiogenic potential and peripheral inflammation of irradiated human umbilical vein endothelial cells(HUVECs). Leptin was transfected into human placenta-derived mesenchymal stem cells(HPMSCs) with lentiviral vectors. HUVECs were irradiated by X-ray at a single dose of 20 Gy. Transwell migration assay was performed to assess the migration of irradiated HUVECs. Based on the Transwell systems, co-culture systems of HPMSCs and irradiated HUVECs were established. Cell proliferation was measured by cell counting kit-8(CCK-8) assay. The secretion of pro-inflammatory cytokines(human granulocyte macrophage-colony stimulating factor(GM-CSF), interleukin(IL)-1α, IL-6, and IL-8) was detected by enzyme-linked immunosorbent assay(ELISA). The expression of pro-angiogenic factors(vascular endothelial growth factor(VEGF) and basic fibroblast growth factor(b FGF)) mRNA was detected by real-time quantitative polymerase chain reaction(RT-qPCR) assay. Relevant molecules of the nuclear factor-κB(NF-κB) and Janus kinase(JAK)/signal transducer and activator of transcription(STAT) signaling pathways were detected by western blot assay. Results showed that leptin-modified HPMSCs(HPMSCs/leptin) exhibited better cell proliferation, migration, and angiogenic potential(expressed more VEGF and bFGF). In both the single HPMSCs/leptin and the co-culture systems of HPMSCs/leptin and irradiated HUVECs, the increased secretion of pro-inflammatory cytokines(human GM-CSF, IL-1α, and IL-6) was associated with the interaction of the NF-κB and JAK/STAT signaling pathways. We conclude that HPMSCs/leptin could promote angiogenic potential and peripheral inflammation of HUVECs after X-ray radiation.
基金supported by the National Natural Science Foundation of China(22162004)the Natural Science Foundation of Guangxi(2022JJD120011)the High-performance Computing Platform of Guangxi University。
文摘5-Hydroxymethylfurfural electrooxidation reaction(HMFOR)is a promising route to produce valueadded chemicals from biomass.Since it involves HMF adsorption and C-H/O-H cleavage,understanding the adsorption behavior and catalytic process of organic molecules on catalysts is important.Herein,the selective adsorption sites of NiMoO are tuned by Ni particles for HMFOR-assisted H2production.Experimental and theoretical calculation results indicate that the synergistic interaction between Ni and NiMoO optimizes the adsorption/desorption of HMF/intermediates/2,5-furandicarboxylic acid(FDCA)and promotes the C-H/O-H bond cleavage,thereby improving the HMFOR kinetics(kNiMoO-Ni/kNiMoO=1.97)and FDCA selectivity(99.3%).When coupled as a two-electrode system,it can drive efficient HMF conversion(FDCA yield:98.5%)and H2production(Faradaic efficiency:99.1%)at 1.45 V.This work thus offers a strategy to tune the adsorption sites of catalyst for efficient HMFOR-assisted H2production.
