This study employs deformation monitoring data acquired during the construction of the Haoji railway large-scale bridge to investigate the displacement behavior of the subgrades,catenary columns,and tracks.Emphasis is...This study employs deformation monitoring data acquired during the construction of the Haoji railway large-scale bridge to investigate the displacement behavior of the subgrades,catenary columns,and tracks.Emphasis is placed on data acquisition and processing methods using total stations and automated monitoring systems.Through a comprehensive analysis of lateral,longitudinal,and vertical displacement data from 26 subgrade monitoring points,catenary columns,and track sections,this research evaluates how construction activities influence railway structures.The results show that displacement variations in the subgrades,catenary columns,and tracks remained within the established alert thresholds,exhibiting stable deformation trends and indicating that any adverse environmental impact was effectively contained.Furthermore,this paper proposes an early warning mechanism based on an automated monitoring system,which can promptly detect abnormal deformations and initiate emergency response procedures,thereby ensuring the safe operation of the railway.The integration of big data analysis and deformation prediction models offers a practical foundation for future safety management in railway construction.展开更多
1.Introduction Cancer continues to be a major cause of global mortality rates,with conventional treatments such as chemotherapy and radiotherapy exhibiting inconsistent efficacy,high costs,and considerable side effect...1.Introduction Cancer continues to be a major cause of global mortality rates,with conventional treatments such as chemotherapy and radiotherapy exhibiting inconsistent efficacy,high costs,and considerable side effects.Over the past decade,a promising alternative has emerged:cancer immunotherapy,which leverages the body's immune system to identify and eradicate cancer cells[1].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
Corex is an alternative ironmaking process and raceway is one of the important areas to maintain the stability of the furnace. The raceway parameters are well established for blast furnace operation. But for Corex pro...Corex is an alternative ironmaking process and raceway is one of the important areas to maintain the stability of the furnace. The raceway parameters are well established for blast furnace operation. But for Corex process,it has not yet been established and optimized. Thus,a mathematical model was developed to determine various raceway parameters such as RAFT （raceway adiabatic flame temperature）,tuyere gas velocity and kinetic energy. The model provides an idea about the raceway geometry,zone temperature and kinetic energy accumulated in tuyere gas. Besides,all the raceway parameters have been analyzed to find out their effects on the Corex process. It is found that RAFT influences the gasification reaction kinetics and higher RAFT generates more CO in reduction gas,which improves the metallisation degree of the DRI in shaft. It is also found that increased gas velocity and kinetic energy generate more fines and demand more coke to maintain char bed permeability. High coke rate increases the production cost and lowers the production of hot metal.展开更多
Rechargeable zinc-air batteries(ZABs)are a promising energy conversion device,which rely critically on electrocatalysts to accelerate their rate-determining reactions such as oxygen reduction(ORR)and oxygen evolution ...Rechargeable zinc-air batteries(ZABs)are a promising energy conversion device,which rely critically on electrocatalysts to accelerate their rate-determining reactions such as oxygen reduction(ORR)and oxygen evolution reactions(OER).Herein,we fabricate a range of bifunctional M-N-C(metal-nitrogen-carbon)catalysts containing M-Nx coordination sites and M/MxC nanoparticles(M=Co,Fe,and Cu)using a new class ofγ-cyclodextrin(CD)based metal-organic framework as the precursor.With the two types of active sites interacting with each other in the catalysts,the obtained Fe@C-FeNC and Co@C-CoNC display superior alkaline ORR activity in terms of low half-wave(E1/2)potential(~0.917 and 0.906 V,respectively),which are higher than Cu@C-CuNC(~0.829 V)and the commercial Pt/C(~0.861 V).As a bifunctional electrocatalyst,the Co@C-CoNC exhibits the best performance,showing a bifunctional ORR/OER overpotential(ΔE)of~0.732 V,which is much lower than that of Fe@C-FeNC(~0.831 V)and Cu@C-CuNC(~1.411 V),as well as most of the robust bifunctional electrocatalysts reported to date.Synchrotron X-ray absorption spectroscopy and density functional theory simulations reveal that the strong electronic correlation between metallic Co nanoparticles and the atomic Co-N4 sites in the Co@C-CoNC catalyst can increase the d-electron density near the Fermi level and thus effectively optimize the adsorption/desorption of intermediates in ORR/OER,resulting in an enhanced bifunctional electrocatalytic performance.The Co@C-CoNC-based rechargeable ZAB exhibited a maximum power density of 162.80 mW cm^(−2) at 270.30 mA cm^(−2),higher than the combination of commercial Pt/C+RuO2(~158.90 mW cm^(−2) at 265.80 mA cm^(−2))catalysts.During the galvanostatic discharge at 10 mA cm^(−2),the ZAB delivered an almost stable discharge voltage of 1.2 V for~140 h,signifying the virtue of excellent bifunctional ORR/OER electrocatalytic activity.展开更多
The coronavirus disease 2019(COVID-19)pandemic has caused a surge in demand for face masks,with the massive consumption of masks leading to an increase in resource-related and environmental con-cerns.In this work,we f...The coronavirus disease 2019(COVID-19)pandemic has caused a surge in demand for face masks,with the massive consumption of masks leading to an increase in resource-related and environmental con-cerns.In this work,we fabricated meltblown polypropylene(mb-PP)-based high-performance planar face masks and investigated the effects of six commonly used disinfection methods and various mask-wearing periods on the reusability of these masks.The results show that,after three cycles of treatment using hot water at 70℃ for 30 min,which is one of the most scalable,user-friendly methods for viral disinfection,the particle filtration efficiency(PFE)of the mask remained almost unchanged.After mask wearing for 24 h and subsequent disinfection using the same treatment procedures,the PFE decreased to 91.3%;the average number of bacterial and fungal colonies was assessed to be 9.2 and 51.6 colony-forming units per gram(CFU∙g^(-1)),respectively;and coliform and pyogenic bacteria were not detected.Both the PFE and the microbial indicators are well above the standard for reusable masks after disinfection.Schlieren pho-tography was then used to assess the capabilities of used and disinfected masks during use;it showed that the masks exhibit a high performance in suppressing the spread of breathed air.展开更多
Long-emission carbon dots(CDs) is triggering immense enthusiasm on account of their intrinsic merits of high chemical stability and excellent optical properties.In this study,a facile and rapid approach was developed ...Long-emission carbon dots(CDs) is triggering immense enthusiasm on account of their intrinsic merits of high chemical stability and excellent optical properties.In this study,a facile and rapid approach was developed for the preparation of barium-doped carbon dots(Ba-CDs) with yellow fluo rescence emission and high quantum yields.Surface chemistry and the chemical architecture of the Ba-CDs was revealed under various spectroscopic methods.This work provides more insights into the effects of charge transfer caused by Ba heteroatoms,which is considered as the most challenging step in the investigation on luminescence mechanism.Remarkably,the prepared Ba-CDs were successfully applied as fluorescent probes in the detection of trace water in organic solvents(ethanol,isopropanol,acetone,tetrahydrofuran).Comparing with traditional fluorescent probes for water detection in organic solvents,Ba-CDs detection provides a more sensitive,much faster and more economical approach.展开更多
With the rapid development of the Internet,the amount of data recorded on the Internet has increased dramatically.It is becoming more and more urgent to effectively obtain the specific information we need from the vas...With the rapid development of the Internet,the amount of data recorded on the Internet has increased dramatically.It is becoming more and more urgent to effectively obtain the specific information we need from the vast ocean of data.In this study,we propose a novel collaborative filtering algorithm for generating recommendations in e-commerce.This study has two main innovations.First,we propose a mechanismthat embeds temporal behavior information to find a neighbor set in which each neighbor has a very significant impact on the current user or item.Second,we propose a novel collaborative filtering algorithm by injecting the neighbor set into probability matrix factorization.We compared the proposed method with several state-of-the-art alternatives on real datasets.The experimental results show that our proposed method outperforms the prevailing approaches.展开更多
The precise determination of zona pellucida (ZP) hardness is largely unknown due to the lack of appropriate measuring and modelling methods. In this study, we have used experimental and theoretical models to describe ...The precise determination of zona pellucida (ZP) hardness is largely unknown due to the lack of appropriate measuring and modelling methods. In this study, we have used experimental and theoretical models to describe the mechanical behavior of a single oocyte cell to improve the assisted reproductive technology (ART) outcomes by assessing oocyte/embryo quality. This paper presents the development of: i) a microinjection model to estimate the force of ZP penetration, ii) a micropipette aspiration model to determine the corresponding hardness, and iii) an experimental procedure to generate the required data for these two models. Our results show that the estimated penetration force provides a performance target for the penetration process during intracytoplasmic sperm injection (ICSI), while the estimated corresponding hardness serves as an indicator of the extent of deformation sustained by the oocyte prior to penetration. Evaluation of these results shows that a routine assessment of ZP hardness under microinjection would allow for the identification of certain oocyte pools for which further manipulation is recommended in order to improve injection, hatching and finally ART outcomes.展开更多
Laser powder bed fusion(LPBF)is a popular additive manufacturing(AM)technique to fabricate metal components.LPBF Ti alloys often exhibit high strength but poor ductility.In this study,we report that trace Y_(2)O_(3) n...Laser powder bed fusion(LPBF)is a popular additive manufacturing(AM)technique to fabricate metal components.LPBF Ti alloys often exhibit high strength but poor ductility.In this study,we report that trace Y_(2)O_(3) nanoparticles added to a pre-alloyed Ti-4Al-4V(Ti44)powder provides an excellent feedstock for LPBF.As-built Ti44-Y_(2)O_(3) materials exhibited a strength-ductility combination that is slightly better than heat-treated LPBF Ti64.Some Y_(2)O_(3) particles may have melted or decomposed during LPBF.From electron microscopy,the addition of Y_(2)O_(3) refined α’martensite laths and weakened variant preference during β→α’transformation.Based on in situ synchrotron X-ray diffraction and elastic-viscoplastic self-consistent(EVPSC)modeling,(c+a)slip was more active in as-built Ti44-Y_(2)O_(3) than in as-built Ti64 or Ti44.This work demonstrates that LPBF can be an excellent method to fabricate metal-nanoparticle composite materials.展开更多
In this paper, a high-performance and low-complexity luminance transient improvement （LTI） algorithm is proposed and efficiently implemented on field programmable gate army （FPGA） devices, which can be widely used...In this paper, a high-performance and low-complexity luminance transient improvement （LTI） algorithm is proposed and efficiently implemented on field programmable gate army （FPGA） devices, which can be widely used to enhance the sharpness of digital video. The proposed algorithm generates the cor- rection signal by using the difference of the outputs of two Gaussian filters with different variances, and then modulates the correction signal adaptively according to the local contrast information of video frames. A 2-D min/max nonlinear filter is employed to suppress overshoots around edges. The proposed algorithm is thoroughly confirmed by experiments and compared with other algorithms on irrkages, which produces steeper edges and better visual quality while suppressing noise and artifacts. And the hardware architecture suitable for FPGA implementation is optimized based on the property of the algorithm and proves to be effective and efficient in many respects, such as resource consumption, performance and reconfigura- bility. The specific implementation details on both Xilinx and Ahera FPGA devices are also described in this paper.展开更多
This paper describes an approach to identify epicyclic and tricyclic motion during projectile flight caused by mass asymmetries in spinstabilized projectiles. Flight video was captured following projectile launch of s...This paper describes an approach to identify epicyclic and tricyclic motion during projectile flight caused by mass asymmetries in spinstabilized projectiles. Flight video was captured following projectile launch of several M110A2E1 155 mm artillery projectiles. These videos were then analyzed using the automated flight video analysis method to attain their initial position and orientation histories.Examination of the pitch and yaw histories clearly indicates that in addition to epicyclic motion's nutation and precession oscillations, an even faster wobble amplitude is present during each spin revolution, even though some of the amplitudes of the oscillation are smaller than 0.02 degree.The results are compared to a sequence of shots where little appreciable mass asymmetries were present, and only nutation and precession frequencies are predominantly apparent in the motion history results. Magnitudes of the wobble motion are estimated and compared to product of inertia measurements of the asymmetric projectiles.展开更多
In the global environment of pursuing resource regeneration and green environmental protection, more and more wasted clothing need to be solved. In order to make full use of the wasted clothing and save land and soil ...In the global environment of pursuing resource regeneration and green environmental protection, more and more wasted clothing need to be solved. In order to make full use of the wasted clothing and save land and soil resources, an idea of wasted clothing's recycling and remanufacturing is put forward. In the new idea a pricing game model is established basing on Stacklberg differential game theory between traditional and remanufactured clothing. In this model, the differences in consumers' willingness to pay and the government's subsidies are considered. Government's optimal subsidy are obtained which ensure not only the interests of manufacturers but also environmental reputation and maximum social benefits. The study is helpful to push the wasted clothing's recycling and remanufacturing plan. It makes some index more precise quantification as government's subsidy, manufacturers and the social benefits. Government and manufactures can make the detailed cooperation plan reference to it.展开更多
The embodied energy/CO2 of buildings in China and Japan, which reflects the characteristic industrial efficiency ofbui｜ding materials, is described in this paper. The energy consumption and CO2 intensities for the do...The embodied energy/CO2 of buildings in China and Japan, which reflects the characteristic industrial efficiency ofbui｜ding materials, is described in this paper. The energy consumption and CO2 intensities for the dominant materials used in buildings are derived from the energy consumption in factories, and the energy consumption to produce equipment is derived from IO （input/output） analysis in order to compare the embodied energy/CO2 for buildings between China and Japan based on the same estimation method. Although the energy consumption of structures in China is two to three times greater than in Japan, the interior finish and air conditioning equipment, for example, are simpler and smaller. As a result, the embodied energy/CO2 of office buildings in China is only 10% to 20% greater than that of Japanese office buildings. Thus, the embodied energy/CO2 of buildings depends on both industrial efficiencies and building design trends of the country.展开更多
The post-fabrication machining of additively manufactured biomedical parts is essential for achieving dimensional accuracy.However,conventional machining encounters issues in dealing with the growing demand for surfac...The post-fabrication machining of additively manufactured biomedical parts is essential for achieving dimensional accuracy.However,conventional machining encounters issues in dealing with the growing demand for surface quality and the inherent defects of parts.To improve the machining quality,the correlation between material variations and ultrasonic machining quality is investigated in terms of material properties.This variation induced by additive strategies is experimentally revealed and the mechanism for this difference is further explained through molten pool dynamic simulation.In addition,to elucidate the unique machining advantages,a hybrid cutting simulation is implemented to analyze the improving behavior of ultrasonic vibration on the common defects of additively manufactured parts.Taken together,this study demonstrates the role that material property differences play in post-fabrication machining and validates the superiority of ultrasonic machining as a post-fabrication machining method for additively manufactured parts.展开更多
Reliable sales forecasts are important to the garment industry. In recent years, the global climate is warming, the weather changes frequently, and clothing sales are affected by weather fluctuations. The purpose of t...Reliable sales forecasts are important to the garment industry. In recent years, the global climate is warming, the weather changes frequently, and clothing sales are affected by weather fluctuations. The purpose of this study is to investigate whether weather data can improve the accuracy of product sales and to establish a corresponding clothing sales forecasting model. This model uses the basic attributes of clothing product data, historical sales data, and weather data. It is based on a random forest, XGB, and GBDT adopting a stacking strategy. We found that weather information is not useful for basic clothing sales forecasts, but it did improve the accuracy of seasonal clothing sales forecasts. The MSE of the dresses, down jackets, and shirts are reduced by 86.03%, 80.14%, and 41.49% on average. In addition, we found that the stacking strategy model outperformed the voting strategy model, with an average MSE reduction of 49.28%. Clothing managers can use this model to forecast their sales when they make sales plans based on weather information.展开更多
In this study, we looked at a method quantifying EEC （embodied energy and CO2） and the effect when we prolonged the building life time particularly through the durable improvement of the structure. Increasing the co...In this study, we looked at a method quantifying EEC （embodied energy and CO2） and the effect when we prolonged the building life time particularly through the durable improvement of the structure. Increasing the covering thickness of concrete for reinforcing bars and the earthquake-resistant strength are methods to increase the durability of the structure. The calculation method to obtain the quantity of concrete and reinforcing bars is provided. The EEC increase is evaluated from the 2005 input-output table in Japan. These results show that EE （embodied energy） in the construction phase is increased by 11% to 20% and EC （embodied CO2） 17% to 32%. However, annual EE is reduced 66% to 72% and EC 70% to 79%,展开更多
Firstly, this article carry on the theory research combined with the related theories of cluster brand and the relevant theories of performance evaluation, and distill four main indicators factors of performance evalu...Firstly, this article carry on the theory research combined with the related theories of cluster brand and the relevant theories of performance evaluation, and distill four main indicators factors of performance evaluation of the cluster brand. Then proceed analysts survey and questionnaire investigation, and then use SPSS software to process date for statistical analysis; use AMOS software to formulate the second-order model, at last, establish structure relationship model of performance evaluation of the cluster brand. Build the model of the cluster brand performance evaluation with fuzzy-synthetic evaluation model.展开更多
The objective of this research is to quantify the EEC （embodied energy/CO2） of a building. The EEC represents the energy consumption and CO2 emissions at individual phases of a building＇s life-cycle, such as constr...The objective of this research is to quantify the EEC （embodied energy/CO2） of a building. The EEC represents the energy consumption and CO2 emissions at individual phases of a building＇s life-cycle, such as construction （including manufacture of materials and equipment）, renewal （including repair work） and demolition. Energy and CO2 emission intensities in terms of 401 sectors were calculated, using the 2005 I-O （input-output） table in Japan. According to our case study conducted from the construction phase to demolition, the EC （embodied CO2） of an office building used for 60 years is 12,044 t-CO2 and 1,093 kg-CO2/m^2 in total. CO2 equivalent emissions （CO2e） by Freon gases, contained in building materials, equipment and devices, were also calculated. As the results, CO2e by insulators was 2% of the building＇s EC and CO2e by refrigerants was 9%-12% of the building＇s EC. It is important to keep reducing emissions of Freon gases contained in refrigerators.展开更多
In July 2009, the 2005 basic Japanese input/output table was publicized together with its physical transaction table. This research paper analyzed the 2005 IO （input/output） table to create building industry-related...In July 2009, the 2005 basic Japanese input/output table was publicized together with its physical transaction table. This research paper analyzed the 2005 IO （input/output） table to create building industry-related intensities and, at the same time, compared the building industry with industries at large for distribution margins and transportation. The analysis of distribution margins separately for middle and purchaser margins found that middle margins in the building industry are minor at 35% of the averages for all industries, while purchaser margins are sizable at 1.8 times, proving that it is an industry for which local production for local consumption is quite effective. CO2 emissions resulting from transportation in the building industry were calculated and concisely characterized. Although the ratio of transportation CO2 emissions to total CO2 emissions in each industry finds almost no difference between general industries and the building industry, transportation CO2 emissions per production value are two to three times heavier than those from general industries to be justified as a transportation-intensive industry.展开更多
文摘This study employs deformation monitoring data acquired during the construction of the Haoji railway large-scale bridge to investigate the displacement behavior of the subgrades,catenary columns,and tracks.Emphasis is placed on data acquisition and processing methods using total stations and automated monitoring systems.Through a comprehensive analysis of lateral,longitudinal,and vertical displacement data from 26 subgrade monitoring points,catenary columns,and track sections,this research evaluates how construction activities influence railway structures.The results show that displacement variations in the subgrades,catenary columns,and tracks remained within the established alert thresholds,exhibiting stable deformation trends and indicating that any adverse environmental impact was effectively contained.Furthermore,this paper proposes an early warning mechanism based on an automated monitoring system,which can promptly detect abnormal deformations and initiate emergency response procedures,thereby ensuring the safe operation of the railway.The integration of big data analysis and deformation prediction models offers a practical foundation for future safety management in railway construction.
基金supported by Australian Centre for AI in Medical Innovation(ACAMI)funded by the Victoria State Government,National University of Singapore(NUHSRO/2020/133/Startup/08,NUHSRO/2023/008/NUSMed/TCE/LOA,NUHSRO/2021/034/TRP/09/Nanomedicine,NUHSRO/2021/044/Kickstart/09/LOA,and 230173-A0001)National Medical Research Council(MOH-001388-00,CG21APR1005,MOH-001500-00,and MOH-001609-00)+1 种基金Singapore Ministry of Education(MOE-000387-00 and MOET32023-0005)National Research Foundation(NRF-000352-00)。
文摘1.Introduction Cancer continues to be a major cause of global mortality rates,with conventional treatments such as chemotherapy and radiotherapy exhibiting inconsistent efficacy,high costs,and considerable side effects.Over the past decade,a promising alternative has emerged:cancer immunotherapy,which leverages the body's immune system to identify and eradicate cancer cells[1].
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Corex is an alternative ironmaking process and raceway is one of the important areas to maintain the stability of the furnace. The raceway parameters are well established for blast furnace operation. But for Corex process,it has not yet been established and optimized. Thus,a mathematical model was developed to determine various raceway parameters such as RAFT （raceway adiabatic flame temperature）,tuyere gas velocity and kinetic energy. The model provides an idea about the raceway geometry,zone temperature and kinetic energy accumulated in tuyere gas. Besides,all the raceway parameters have been analyzed to find out their effects on the Corex process. It is found that RAFT influences the gasification reaction kinetics and higher RAFT generates more CO in reduction gas,which improves the metallisation degree of the DRI in shaft. It is also found that increased gas velocity and kinetic energy generate more fines and demand more coke to maintain char bed permeability. High coke rate increases the production cost and lowers the production of hot metal.
基金supported by the Shenzhen Government’s Plan of Science and Technology(JCYJ20190808121407676 and 20200813142301001)National Natural Science Foundation of China(22178223 and 22262010)+1 种基金Guangxi Science and Technology Fund for Distinguished High-Talent Introduction Program(No.RZ2200002233AC22035091).
文摘Rechargeable zinc-air batteries(ZABs)are a promising energy conversion device,which rely critically on electrocatalysts to accelerate their rate-determining reactions such as oxygen reduction(ORR)and oxygen evolution reactions(OER).Herein,we fabricate a range of bifunctional M-N-C(metal-nitrogen-carbon)catalysts containing M-Nx coordination sites and M/MxC nanoparticles(M=Co,Fe,and Cu)using a new class ofγ-cyclodextrin(CD)based metal-organic framework as the precursor.With the two types of active sites interacting with each other in the catalysts,the obtained Fe@C-FeNC and Co@C-CoNC display superior alkaline ORR activity in terms of low half-wave(E1/2)potential(~0.917 and 0.906 V,respectively),which are higher than Cu@C-CuNC(~0.829 V)and the commercial Pt/C(~0.861 V).As a bifunctional electrocatalyst,the Co@C-CoNC exhibits the best performance,showing a bifunctional ORR/OER overpotential(ΔE)of~0.732 V,which is much lower than that of Fe@C-FeNC(~0.831 V)and Cu@C-CuNC(~1.411 V),as well as most of the robust bifunctional electrocatalysts reported to date.Synchrotron X-ray absorption spectroscopy and density functional theory simulations reveal that the strong electronic correlation between metallic Co nanoparticles and the atomic Co-N4 sites in the Co@C-CoNC catalyst can increase the d-electron density near the Fermi level and thus effectively optimize the adsorption/desorption of intermediates in ORR/OER,resulting in an enhanced bifunctional electrocatalytic performance.The Co@C-CoNC-based rechargeable ZAB exhibited a maximum power density of 162.80 mW cm^(−2) at 270.30 mA cm^(−2),higher than the combination of commercial Pt/C+RuO2(~158.90 mW cm^(−2) at 265.80 mA cm^(−2))catalysts.During the galvanostatic discharge at 10 mA cm^(−2),the ZAB delivered an almost stable discharge voltage of 1.2 V for~140 h,signifying the virtue of excellent bifunctional ORR/OER electrocatalytic activity.
基金supported by National Key Research and Development Program of China (2020YFC0844800)the Science and Technology Planning Project of Beijing (Z201100007520006)
文摘The coronavirus disease 2019(COVID-19)pandemic has caused a surge in demand for face masks,with the massive consumption of masks leading to an increase in resource-related and environmental con-cerns.In this work,we fabricated meltblown polypropylene(mb-PP)-based high-performance planar face masks and investigated the effects of six commonly used disinfection methods and various mask-wearing periods on the reusability of these masks.The results show that,after three cycles of treatment using hot water at 70℃ for 30 min,which is one of the most scalable,user-friendly methods for viral disinfection,the particle filtration efficiency(PFE)of the mask remained almost unchanged.After mask wearing for 24 h and subsequent disinfection using the same treatment procedures,the PFE decreased to 91.3%;the average number of bacterial and fungal colonies was assessed to be 9.2 and 51.6 colony-forming units per gram(CFU∙g^(-1)),respectively;and coliform and pyogenic bacteria were not detected.Both the PFE and the microbial indicators are well above the standard for reusable masks after disinfection.Schlieren pho-tography was then used to assess the capabilities of used and disinfected masks during use;it showed that the masks exhibit a high performance in suppressing the spread of breathed air.
基金financially supported by the National Natural Science Foundation of China (NSFC,No.21805024)Science Foundation of China University of Petroleum (Nos. 2462019QNXZ02,2462018BJC004)+1 种基金the Scientifc and Technological Research Program of Chongqing Municipal Education Commission (No.KJ QN202001335)the Research Program ofYongchuan Science and Technology Commission (Ycstc,No.2018nb1402)。
文摘Long-emission carbon dots(CDs) is triggering immense enthusiasm on account of their intrinsic merits of high chemical stability and excellent optical properties.In this study,a facile and rapid approach was developed for the preparation of barium-doped carbon dots(Ba-CDs) with yellow fluo rescence emission and high quantum yields.Surface chemistry and the chemical architecture of the Ba-CDs was revealed under various spectroscopic methods.This work provides more insights into the effects of charge transfer caused by Ba heteroatoms,which is considered as the most challenging step in the investigation on luminescence mechanism.Remarkably,the prepared Ba-CDs were successfully applied as fluorescent probes in the detection of trace water in organic solvents(ethanol,isopropanol,acetone,tetrahydrofuran).Comparing with traditional fluorescent probes for water detection in organic solvents,Ba-CDs detection provides a more sensitive,much faster and more economical approach.
基金supported by the National Natural Science Foundation of China under Grant Nos.81873915,61702225 and 61806026Ministry of Science and Technology Key Research and Development Program of China under Grant No.2018YFC0116902+3 种基金by the Natural Science Foundation of Jiangsu Province under Grant No.BK20180956by the 2018 Six Talent Peaks Project of Jiangsu Province under Grant No.XYDXX-127by the Science and Technology demonstration project of social development of Wuxi under Grant WX18IVJN002by the Philosophy and Social Science Foundation of Jiangsu Province(18YSC009).
文摘With the rapid development of the Internet,the amount of data recorded on the Internet has increased dramatically.It is becoming more and more urgent to effectively obtain the specific information we need from the vast ocean of data.In this study,we propose a novel collaborative filtering algorithm for generating recommendations in e-commerce.This study has two main innovations.First,we propose a mechanismthat embeds temporal behavior information to find a neighbor set in which each neighbor has a very significant impact on the current user or item.Second,we propose a novel collaborative filtering algorithm by injecting the neighbor set into probability matrix factorization.We compared the proposed method with several state-of-the-art alternatives on real datasets.The experimental results show that our proposed method outperforms the prevailing approaches.
文摘The precise determination of zona pellucida (ZP) hardness is largely unknown due to the lack of appropriate measuring and modelling methods. In this study, we have used experimental and theoretical models to describe the mechanical behavior of a single oocyte cell to improve the assisted reproductive technology (ART) outcomes by assessing oocyte/embryo quality. This paper presents the development of: i) a microinjection model to estimate the force of ZP penetration, ii) a micropipette aspiration model to determine the corresponding hardness, and iii) an experimental procedure to generate the required data for these two models. Our results show that the estimated penetration force provides a performance target for the penetration process during intracytoplasmic sperm injection (ICSI), while the estimated corresponding hardness serves as an indicator of the extent of deformation sustained by the oocyte prior to penetration. Evaluation of these results shows that a routine assessment of ZP hardness under microinjection would allow for the identification of certain oocyte pools for which further manipulation is recommended in order to improve injection, hatching and finally ART outcomes.
基金supported by the National Key Research and Development Program of China(No.2021YFB3702602)the National Natural Science Foundation of Chin a(No.U2032124)the support by the Ministry of Education,Singapore,under its Academic Research Fund Tier 1(No.A-0009475-01-00).
文摘Laser powder bed fusion(LPBF)is a popular additive manufacturing(AM)technique to fabricate metal components.LPBF Ti alloys often exhibit high strength but poor ductility.In this study,we report that trace Y_(2)O_(3) nanoparticles added to a pre-alloyed Ti-4Al-4V(Ti44)powder provides an excellent feedstock for LPBF.As-built Ti44-Y_(2)O_(3) materials exhibited a strength-ductility combination that is slightly better than heat-treated LPBF Ti64.Some Y_(2)O_(3) particles may have melted or decomposed during LPBF.From electron microscopy,the addition of Y_(2)O_(3) refined α’martensite laths and weakened variant preference during β→α’transformation.Based on in situ synchrotron X-ray diffraction and elastic-viscoplastic self-consistent(EVPSC)modeling,(c+a)slip was more active in as-built Ti44-Y_(2)O_(3) than in as-built Ti64 or Ti44.This work demonstrates that LPBF can be an excellent method to fabricate metal-nanoparticle composite materials.
基金Supported by the National Science and Technology Support Projects Funded by Ministry of Science & Technology of China (No. 2006BAK07B04)
文摘In this paper, a high-performance and low-complexity luminance transient improvement （LTI） algorithm is proposed and efficiently implemented on field programmable gate army （FPGA） devices, which can be widely used to enhance the sharpness of digital video. The proposed algorithm generates the cor- rection signal by using the difference of the outputs of two Gaussian filters with different variances, and then modulates the correction signal adaptively according to the local contrast information of video frames. A 2-D min/max nonlinear filter is employed to suppress overshoots around edges. The proposed algorithm is thoroughly confirmed by experiments and compared with other algorithms on irrkages, which produces steeper edges and better visual quality while suppressing noise and artifacts. And the hardware architecture suitable for FPGA implementation is optimized based on the property of the algorithm and proves to be effective and efficient in many respects, such as resource consumption, performance and reconfigura- bility. The specific implementation details on both Xilinx and Ahera FPGA devices are also described in this paper.
文摘This paper describes an approach to identify epicyclic and tricyclic motion during projectile flight caused by mass asymmetries in spinstabilized projectiles. Flight video was captured following projectile launch of several M110A2E1 155 mm artillery projectiles. These videos were then analyzed using the automated flight video analysis method to attain their initial position and orientation histories.Examination of the pitch and yaw histories clearly indicates that in addition to epicyclic motion's nutation and precession oscillations, an even faster wobble amplitude is present during each spin revolution, even though some of the amplitudes of the oscillation are smaller than 0.02 degree.The results are compared to a sequence of shots where little appreciable mass asymmetries were present, and only nutation and precession frequencies are predominantly apparent in the motion history results. Magnitudes of the wobble motion are estimated and compared to product of inertia measurements of the asymmetric projectiles.
文摘In the global environment of pursuing resource regeneration and green environmental protection, more and more wasted clothing need to be solved. In order to make full use of the wasted clothing and save land and soil resources, an idea of wasted clothing's recycling and remanufacturing is put forward. In the new idea a pricing game model is established basing on Stacklberg differential game theory between traditional and remanufactured clothing. In this model, the differences in consumers' willingness to pay and the government's subsidies are considered. Government's optimal subsidy are obtained which ensure not only the interests of manufacturers but also environmental reputation and maximum social benefits. The study is helpful to push the wasted clothing's recycling and remanufacturing plan. It makes some index more precise quantification as government's subsidy, manufacturers and the social benefits. Government and manufactures can make the detailed cooperation plan reference to it.
基金supported in part by the IEA/EBC/Annex57 Committee of Japan,organized through the IBEC(Institute for Building Environment and Energy Conservation).
文摘The embodied energy/CO2 of buildings in China and Japan, which reflects the characteristic industrial efficiency ofbui｜ding materials, is described in this paper. The energy consumption and CO2 intensities for the dominant materials used in buildings are derived from the energy consumption in factories, and the energy consumption to produce equipment is derived from IO （input/output） analysis in order to compare the embodied energy/CO2 for buildings between China and Japan based on the same estimation method. Although the energy consumption of structures in China is two to three times greater than in Japan, the interior finish and air conditioning equipment, for example, are simpler and smaller. As a result, the embodied energy/CO2 of office buildings in China is only 10% to 20% greater than that of Japanese office buildings. Thus, the embodied energy/CO2 of buildings depends on both industrial efficiencies and building design trends of the country.
基金supported by the National Natural Science Foun-dation of China(Nos.51975112 and52375412)the Fundamental Research Funds for Central Universities(No.N2203003)the Singapore Ministry of Education(Grant No.A-8001225-00-00).
文摘The post-fabrication machining of additively manufactured biomedical parts is essential for achieving dimensional accuracy.However,conventional machining encounters issues in dealing with the growing demand for surface quality and the inherent defects of parts.To improve the machining quality,the correlation between material variations and ultrasonic machining quality is investigated in terms of material properties.This variation induced by additive strategies is experimentally revealed and the mechanism for this difference is further explained through molten pool dynamic simulation.In addition,to elucidate the unique machining advantages,a hybrid cutting simulation is implemented to analyze the improving behavior of ultrasonic vibration on the common defects of additively manufactured parts.Taken together,this study demonstrates the role that material property differences play in post-fabrication machining and validates the superiority of ultrasonic machining as a post-fabrication machining method for additively manufactured parts.
文摘Reliable sales forecasts are important to the garment industry. In recent years, the global climate is warming, the weather changes frequently, and clothing sales are affected by weather fluctuations. The purpose of this study is to investigate whether weather data can improve the accuracy of product sales and to establish a corresponding clothing sales forecasting model. This model uses the basic attributes of clothing product data, historical sales data, and weather data. It is based on a random forest, XGB, and GBDT adopting a stacking strategy. We found that weather information is not useful for basic clothing sales forecasts, but it did improve the accuracy of seasonal clothing sales forecasts. The MSE of the dresses, down jackets, and shirts are reduced by 86.03%, 80.14%, and 41.49% on average. In addition, we found that the stacking strategy model outperformed the voting strategy model, with an average MSE reduction of 49.28%. Clothing managers can use this model to forecast their sales when they make sales plans based on weather information.
文摘In this study, we looked at a method quantifying EEC （embodied energy and CO2） and the effect when we prolonged the building life time particularly through the durable improvement of the structure. Increasing the covering thickness of concrete for reinforcing bars and the earthquake-resistant strength are methods to increase the durability of the structure. The calculation method to obtain the quantity of concrete and reinforcing bars is provided. The EEC increase is evaluated from the 2005 input-output table in Japan. These results show that EE （embodied energy） in the construction phase is increased by 11% to 20% and EC （embodied CO2） 17% to 32%. However, annual EE is reduced 66% to 72% and EC 70% to 79%,
文摘Firstly, this article carry on the theory research combined with the related theories of cluster brand and the relevant theories of performance evaluation, and distill four main indicators factors of performance evaluation of the cluster brand. Then proceed analysts survey and questionnaire investigation, and then use SPSS software to process date for statistical analysis; use AMOS software to formulate the second-order model, at last, establish structure relationship model of performance evaluation of the cluster brand. Build the model of the cluster brand performance evaluation with fuzzy-synthetic evaluation model.
文摘The objective of this research is to quantify the EEC （embodied energy/CO2） of a building. The EEC represents the energy consumption and CO2 emissions at individual phases of a building＇s life-cycle, such as construction （including manufacture of materials and equipment）, renewal （including repair work） and demolition. Energy and CO2 emission intensities in terms of 401 sectors were calculated, using the 2005 I-O （input-output） table in Japan. According to our case study conducted from the construction phase to demolition, the EC （embodied CO2） of an office building used for 60 years is 12,044 t-CO2 and 1,093 kg-CO2/m^2 in total. CO2 equivalent emissions （CO2e） by Freon gases, contained in building materials, equipment and devices, were also calculated. As the results, CO2e by insulators was 2% of the building＇s EC and CO2e by refrigerants was 9%-12% of the building＇s EC. It is important to keep reducing emissions of Freon gases contained in refrigerators.
文摘In July 2009, the 2005 basic Japanese input/output table was publicized together with its physical transaction table. This research paper analyzed the 2005 IO （input/output） table to create building industry-related intensities and, at the same time, compared the building industry with industries at large for distribution margins and transportation. The analysis of distribution margins separately for middle and purchaser margins found that middle margins in the building industry are minor at 35% of the averages for all industries, while purchaser margins are sizable at 1.8 times, proving that it is an industry for which local production for local consumption is quite effective. CO2 emissions resulting from transportation in the building industry were calculated and concisely characterized. Although the ratio of transportation CO2 emissions to total CO2 emissions in each industry finds almost no difference between general industries and the building industry, transportation CO2 emissions per production value are two to three times heavier than those from general industries to be justified as a transportation-intensive industry.
