Based on the split hopkinson pressure bar(SHPB)tests results,the cubic specimens have been numerically modeled in this paper to investigate the impact of key factors,such as the rise time,duration,and incident pulse s...Based on the split hopkinson pressure bar(SHPB)tests results,the cubic specimens have been numerically modeled in this paper to investigate the impact of key factors,such as the rise time,duration,and incident pulse shape,on achieving stress uniformity.After analysis,the paper provides actionable methods aimed at optimizing the conditions for stress uniformity within the cubic specimen.Finally,the lateral inertia effect of cubic specimen has been scrutinized to address the existing gap in this academic area.展开更多
This paper studies the problem of the spectral radius of the uniform hypergraph determined by the signless Laplacian matrix.The upper bound of the spectral radius of a uniform hypergraph is obtained by using Rayleigh ...This paper studies the problem of the spectral radius of the uniform hypergraph determined by the signless Laplacian matrix.The upper bound of the spectral radius of a uniform hypergraph is obtained by using Rayleigh principle and the perturbation of the spectral radius under moving the edge operation,and the extremal hypergraphs are characterized for both supertree and unicyclic hypergraphs.The spectral radius of the graph is generalized.展开更多
At our school,we have to wear uniforms every day.The problem is that all my classmates think the uniforms are ugly.We think young people should look smart,because①we would like to wear our own clothes.Our teachers th...At our school,we have to wear uniforms every day.The problem is that all my classmates think the uniforms are ugly.We think young people should look smart,because①we would like to wear our own clothes.Our teachers think that if we do that,we will concentrate much②on our clothes than our studies.We don't agree.展开更多
The double-sided lapping process is extensively employed in the manufacturing of wafers,optical windows,and seal rings due to its high efficiency and ability to achieve precise flatness.However,limited research has ex...The double-sided lapping process is extensively employed in the manufacturing of wafers,optical windows,and seal rings due to its high efficiency and ability to achieve precise flatness.However,limited research has explored the thickness uniformity among different workpieces after double-sided lapping,and the underlying mechanism remains unclear.To address the demand for higher precision,this paper first analyzed the relative kinematic model between the workpiece and the lapping plate to clarify the causes of thickness variations among workpieces after double-sided lapping.Subsequently,a finite element method(FEM)model was developed to account for the pressure distribution on the workpiece surfaces at the initial stage of the process.The results indicate that the number of workpieces influences the final thickness variation.Then,various sets of thin copper plates with different thicknesses were lapped,and the findings revealed that five copper plates processed simultaneously exhibited more uniform thickness compared to the three plates.The experimental results align well with the theoretical analysis.Ultimately,a thickness variation of less than 6μm was achieved on five copper plates measuringΦ100×2.9 mm.This study presents a comprehensive analysis of the mechanisms influencing thickness uniformity in the double-sided lapping process and provides practical guidelines for optimizing the process to achieve stringent precision standards in industrial applications.展开更多
In this study,we present a unified sparsity-driven framework that significantly enhances motion deblurring performance by integrating two key components:a custom-designed dataset and a low-rank module(LRM).This framew...In this study,we present a unified sparsity-driven framework that significantly enhances motion deblurring performance by integrating two key components:a custom-designed dataset and a low-rank module(LRM).This framework leverages the inherent sparsity of per-pixel blur kernels to bolster both deblurring accuracy and model interpretability.Firstly,we propose an adaptive-basis decomposition-based deblurring(ADD)approach,which constructs a tailored training dataset to enhance the generalization capacity of the deblurring network.The ADD framework adaptively decomposes motion blur into sparse basis elements,effectively addressing the intricacies associated with non-uniform blurs.Secondly,an LRM is proposed to improve the interpretability of deblurring models as a plug-and-play module,primarily designed to identify and harness the intrinsic sparse features in sharp images.A series of ablation studies have been conducted to substantiate the synergistic advantages of combining the proposed ADD with the LRM for overall improvement in deblurring efficacy.Subsequently,we empirically demonstrate through rigorous experimentation that incorporating the LRM into an existing Uformer network leads to substantial enhancement in reconstruction performance.This integration yields a sparsity-guided low-rank network(SGLRN).Operating under the overarching principle of sparsity,SGLRN consistently outperforms state-of-the-art methods across multiple standard deblurring benchmarks.Comprehensive experimental results,assessed through quantitative metrics and qualitative visual evaluations,provide compelling evidence of its effectiveness.The overall deblurring results are available at Google Drive.展开更多
The mineralization process of microbial-induced calcium carbonate precipitation(MICP)is influenced by many factors,and the uniformity of the calcium carbonate precipitation has become the main focus and challenge for ...The mineralization process of microbial-induced calcium carbonate precipitation(MICP)is influenced by many factors,and the uniformity of the calcium carbonate precipitation has become the main focus and challenge for MICP technology.In this study,the uniformity of the saturated calcareous sand treated with MICP was in-vestigated through one-dimensional calcareous sand column tests and model tests.The coefficient of variation was employed in one-dimensional sand column tests to investigate the impact of injection rate,cementation solution concentration,and number of injection cycles on the uniformity of the MICP treatment.Additionally,model tests were conducted to investigate the impact of injection pressure and methods on the treatment range and uniformity under three-dimensional seepage conditions.Test results demonstrate that the reinforcement strength and uniformity are significantly influenced by the injection rate of the cementation solution,with a rate of 3 mL/min,yielding a favorable treatment effect.Excessive concentration of the cementation solution can lead to significant non-uniformity and a reduction in the compressive strength of MICP-treated samples.Conversely,excessively low concentrations may result in decreased bonding efficiency.Among the four considered con-centrations,0.5 mol/L and 1 mol/L exhibit superior reinforcing effects.The morphological development of calcareous sandy foundation reinforcement is associated with the spatial distribution pattern of the bacterial solution,exhibiting a relatively larger reinforcement area in proximity to the lower region of the model and a gradually decreasing range towards the upper part.Under three-dimensional seepage conditions,in addition to the non-uniform radial cementation along the injection pipe,there is also vertical heterogeneity of cementation along the length of the injection pipe due to gravitational effects,resulting in preferential deposition of calcium carbonate at the lower section,The application of injection pressure and a double-pipe circulation injection method can mitigate the accumulation of bacterial solution and cementation solution at the bottom,thereby improving the reinforcement range and uniformity.展开更多
On the morning of May 31st,the parallel forum"Seeking Harmony without Uniformity in Mutual Learning:Diversity of Civilisations from the Sinologists'Perspective"was held in Dunhuang.The forum was hosted b...On the morning of May 31st,the parallel forum"Seeking Harmony without Uniformity in Mutual Learning:Diversity of Civilisations from the Sinologists'Perspective"was held in Dunhuang.The forum was hosted by the Chinese Association for International Understanding and organised by Beijing Language and Culture University.Leading Sinologists and Chinese culture researchers from Europe,Asia and Latin America gathered to discuss the theme of civilisational diversity and explore pathways for coexistence and mutual enrichment.展开更多
Ceramic hollow spheres have great potential for deep-sea applications.However,the irregularity of the conventional molding process,among other reasons,results in low wall thickness uniformity of hollow spheres.To solv...Ceramic hollow spheres have great potential for deep-sea applications.However,the irregularity of the conventional molding process,among other reasons,results in low wall thickness uniformity of hollow spheres.To solve this problem,in this work,we developed a biaxial rotation grouting process for deep-sea ceramic hollow buoyancy spheres,which improves the drawbacks of the traditional rotary grouting method that results in poor wall thickness uniformity of the hollow spheres due to its irregular rotational processing.In this paper,an experimental study was carried out to investigate the effects of different rotational methods,rotational speeds,rotational time,solid phase content,etc.on the wall thickness uniformity of ceramic hollow spheres.The results show that the hollow floating balls prepared by the biaxial rotation method have the lowest wall thickness standard deviation(0.04)when the rotation speed is 60 rpm,the molding time is 8 min,and the solid phase content is 70 wt%.After the hydrostatic pressure test of 120 MPa,the hydrostatic compressive strength of hollow spheres prepared by the biaxial rotation method was increased by 31.67%compared with that of the traditional process.展开更多
Polyvinylidene fluoride(PVDF)/garnet composite polymer electrolytes(CPEs) have shown great potential in the development of solid-state lithium metal batteries(SSLMBs) due to their excellent flexibility, high ionic con...Polyvinylidene fluoride(PVDF)/garnet composite polymer electrolytes(CPEs) have shown great potential in the development of solid-state lithium metal batteries(SSLMBs) due to their excellent flexibility, high ionic conductivity and superior mechanical strength.However, uneven dispersion of garnet fillers in CPEs would lead to deterioration of lithium metal batteries(LMBs) performance and severely limit their widespread application. Considering the rapidly growing research of addressing above-mentioned issue, herein, recent progress in the design and fabrication of uniformly dispersed fillers in PVDF/garnet CPEs for high-performance SSLMBs is summarized. We firstly analyze the mechanism for the aggregation of inorganic fillers, and provide a detailed introduction to the strategies for solving the uneven dispersion of nanoparticles in solid electrolytes. Moreover, we also comprehensively summarize their applications in PVDF/garnet electrolytes and their impact on the electrochemical performance of SSLMBs. Finally, the application challenges and future prospects of PVDF/garnet CPEs in SSLMBs were also proposed to promote their further development. It is anticipated that this review could inspire ongoing research interest in rational designing and fabricating novel CPEs for high-performance SSLMBs.展开更多
Characteristics of heat transfer and flow of Newtonian and non-Newtonian fluids through porous walls and in porous media are studied due to their wide range of applications including geothermal reservoirs,heat exchang...Characteristics of heat transfer and flow of Newtonian and non-Newtonian fluids through porous walls and in porous media are studied due to their wide range of applications including geothermal reservoirs,heat exchangers,marine propulsion,and aerodynamics.The current study investigates the characteristics of heat transport in a reactive third-grade fluid,moving through permeable parallel plates,with uniform suction/injection velocity.The two permeable,parallel plates are maintained at the same,constant temperature.After being transformed into its dimensionless equivalent,governing equations are solved by employing the Least Squares Method(LSM).The LSM results are further validated with numerical solutions for temperature and velocity.The impact of cross-flow Reynolds number,Peclet number,heat generation parameter,non-Newtonian parameter,and Brinkman number on entropy generation,velocity,temperature,and Bejan number are investigated.Theresults indicate that temperature distribution is significantly influenced by the third-grade fluid parameter.The maximum temperature drops from almost 0.12 to 0.10 as the third-grade fluid parameter increases from0.05 to 0.4.When the cross-flow Reynolds number is raised from 0.05 to 3,the maximum temperature drops from 0.12 to around 0.09.Temperature is strongly influenced by the heat generation parameter.A greater understanding of the thermal characteristics necessary for the design of a variety of systems,such as heat exchangers,marine propulsion,aerodynamic systems,etc.,may be gained from the findings of the current study.展开更多
The practical application of lithium(Li)metal batteries(LMBs)faces challenges due to the irreversible Li deposition/dissolution process,which promotes Li dendrite growth with severe parasitic reactions during cycling....The practical application of lithium(Li)metal batteries(LMBs)faces challenges due to the irreversible Li deposition/dissolution process,which promotes Li dendrite growth with severe parasitic reactions during cycling.To address these issues,achieving uniform Li‐ion flux and improving Li‐ion conductivity of the separator are the top priorities.Herein,a separator(PCELS)with enhanced Li‐ion conductivity,composed of polymer,ceramic,and electrically conductive carbon,is proposed to facilitate fast Li‐ion transport kinetics and increase Li deposition uniformity of the LMBs.The PCELS immobilizes PF6–anions with high adsorption energies,leading to a high Li‐ion transference number.Simultaneously,the PCELS shows excellent electrolyte wettability on both its sides,promoting rapid ion transport.Moreover,the electrically conductive carbon within the PCELS provides additional electron transport channels,enabling efficient charge transfer and uniform Li‐ion flux.With these advantages,the PCELS achieves rapid Li‐ion transport kinetics and uniform Li deposition,demonstrating excellent cycling stability over 100 cycles at a high current density of 12.0 mA cm^(-2).Furthermore,the PCELS shows stable cycling performances in Li–S cell tests and delivers an excellent capacity retention of 95.45%in the Li|LiFePO_(4) full‐cell test with a high areal capacity of over 5.5 mAh cm^(-2).展开更多
1 Introduction In highway construction,flled embankments are trapezoidal,and the ground is always improved by sand wells or columns.During embankment construction,because the width and height of the embankment are cha...1 Introduction In highway construction,flled embankments are trapezoidal,and the ground is always improved by sand wells or columns.During embankment construction,because the width and height of the embankment are changing,a non-uniform load that varies with time and lateral location is applied to the underlying ground.The consolidation phenomenon under two-dimensional(2D)conditions will keep pace with the construction of the embankment.In addition,because of evaporation and rainfall,the soils are mostly unsaturated.Therefore,it is meaningful to research the consolidation properties of unsaturated ground under non-uniform loading.展开更多
In soil dynamics,cyclic tests on sands have been extensively studied over the past several decades.Among the natural materials most susceptible to strength loss due to earthquakes,sands are commonly tested under varyi...In soil dynamics,cyclic tests on sands have been extensively studied over the past several decades.Among the natural materials most susceptible to strength loss due to earthquakes,sands are commonly tested under varying loading,frequency,and drainage conditions.Traditionally,it has been assumed that pore pressure increases with constant strength loss once the threshold for pore pressure build-up is reached.However,recent studies have revealed that at small strains,the material initially hardens despite the generation of pore pressure.This paper presents the response and degradation of uniformly graded Drava River sand(DrOS018),similar to well-known sands such as Toyoura,Nevada or Ottawa sands,and the initial hardening phenomena that occur around threshold strains.Tests were conducted using a triaxial cyclic device at three relative densities and cell pressures(100 kPa,200 kPa,and 400 kPa)under undrained conditions.Strain-controlled tests were conducted at 0.1 Hz and 0.05 Hz using sinusoidal loading,with samples prepared by under-compaction.After crossing the threshold,the sand initially shows hardening(degradation index greater than 1)with up to a 35%increase in pore pressure,followed by strength degradation at higher strains.This study is critical for seismic design and safety,particularly for fully saturated sands in coastal and high water table areas.The findings enhance our understanding of liquefaction potential and site response,aiding more informed engineering practices by contributing to enhanced knowledge in soil dynamics and improved predictive models.The results support effective mitigation strategies and infrastructure resilience in earthquake-prone regions such as Croatia.展开更多
At present,the naked-eye three-dimensional(3D)display technology still has some drawbacks,such as low brightness uniformity,high crosstalk,low light efficiency,short viewing distance,and the manufacturing is difficult...At present,the naked-eye three-dimensional(3D)display technology still has some drawbacks,such as low brightness uniformity,high crosstalk,low light efficiency,short viewing distance,and the manufacturing is difficulty.Based on the principle of naked-eye 3D display and the Fresnel optical theory,this paper designs a Fresnel lens array and the star-shaped liquid crystal display(LCD)switch of unit LCD screen to achieve low-crosstalk and high brightness uniformity for the autostereoscopic 3D display.The unit parameters of a 139.7 cm 4K model autostereoscopic 3D displayer are provided and they are optimized by the TracePro software.The results show that when the pitch of the Fresnel lens on the exit surface is 0.304 mm,the width of each serration of Fresnel lens is 0.0234 mm,the length of the Fresnel lens is 2.87 mm,and the center height of star-shaped LCD switch is 0.030 mm,the center length is 0.040 mm,the width of star-shaped LCD switch is 0.050 mm,and the image crosstalk is less than 2%when the viewing distance is 2.50 m.The problem on the brightness of the image in different positions is improved.展开更多
Ultrafine metal nanoparticles are crucial for various applications,such as energy storage,catalysis,electronics,and biomedicine,owing to their high surfaceto-volume ratio and unique electronic properties.However,conve...Ultrafine metal nanoparticles are crucial for various applications,such as energy storage,catalysis,electronics,and biomedicine,owing to their high surfaceto-volume ratio and unique electronic properties.However,conventional nanoparticle synthesis methods often face challenges like irregular shapes and agglomeration,leading to compromised functionality.To address these challenges,this paper introduces a novel,rapid,high-temperature thermal radiation heating for the ultrafast synthesis and dispersion of metal nanoparticles.Utilizing the heating properties of carbon materials,the direct Joule heating generated by them rises to 1800-2000 K within~200 ms,followed by cooling to room temperature at a rate of 2×10^(3)K s^(-1).展开更多
To improve the quality of the illumination distribution,one novel indoor visible light communication(VLC)system,which is jointly assisted by the angle-diversity transceivers and simultaneous transmission and reflectio...To improve the quality of the illumination distribution,one novel indoor visible light communication(VLC)system,which is jointly assisted by the angle-diversity transceivers and simultaneous transmission and reflection-intelligent reflecting surface(STAR-IRS),has been proposed in this work.A Harris Hawks optimizer algorithm(HHOA)-based two-stage alternating iteration algorithm(TSAIA)is presented to jointly optimize the magnitude and uniformity of the received optical power.Besides,to demonstrate the superiority of the proposed strategy,several benchmark schemes are simulated and compared.Results showed that compared to other optimization strategies,the TSAIA scheme is more capable of balancing the average value and variance of the received optical power,when the maximal ratio combining(MRC)strategy is adopted at the receiver.Moreover,as the number of the STAR-IRS elements increases,the optical power variance of the system optimized by TSAIA scheme would become smaller while the average optical power would get larger.This study will benefit the design of received optical power distribution for indoor VLC systems.展开更多
As a class of crystalline porous materials,metal-organic frameworks(MOFs)have shown unique advantages in the fields of catalysis,gas storage and separation,but their inherent microporous structure(pore diameter<2 n...As a class of crystalline porous materials,metal-organic frameworks(MOFs)have shown unique advantages in the fields of catalysis,gas storage and separation,but their inherent microporous structure(pore diameter<2 nm)severely limits their application in scenarios such as macromolecular mass transfer and so on.In order to overcome this re-striction,mesoporous MOFs(meso-MOFs)with a larger aperture(2-50 nm)have attracted much attention due to their potential applications in biological macromolecular catalysis,energy storage and other fields.To date,how to accurately regulate its mesopore topology and pore ordering still faces important technical challenges.展开更多
The effect of forging passes on the refinement of high purity aluminum during multi-forging was investigated. The attention was focused on the structure uniformity due to deformation uniformity and the grain refinemen...The effect of forging passes on the refinement of high purity aluminum during multi-forging was investigated. The attention was focused on the structure uniformity due to deformation uniformity and the grain refinement limitation with very high strains. The results show that the fine grain zone in the center of sample expands gradually with the increase of forging passes. When the forging passes reach 6, an X-shape fine grain zone is initially formed. With a further increase of the passes, this X-shape zone tends to spread the whole sample. Limitation in the structural refinement is observed with increasing strains during multi-forging process at the room temperature. The grains size in the center is refined to a certain size （110 μm as forging passes reach 12, and there is no further grain refinement in the center with increasing the forging passes to 24. However, the size of the coarse grains near the surface is continuously decreased with increasing the forging passes to 24.展开更多
[Objective]This study was to optimize callus induction medium for Schisandga chinensis Baill.[Method]Using callus induction rate as an indicator,uniform design was employed to optimize hormone combination at poly-fact...[Objective]This study was to optimize callus induction medium for Schisandga chinensis Baill.[Method]Using callus induction rate as an indicator,uniform design was employed to optimize hormone combination at poly-factors and poly-levels for callus induction from Schisandga chinensis Baill.[Results]Optimal hormone combinations depended on different explants：optimum medium for both tender leaf and petiole was MS ＋3 mg/L 6-BA,for stem segment was MS ＋3 mg/L 6-BA ＋0.6 mg/L NAA.[Conclusion]Uniform design is a time-saving and convenient method for the optimum medium for callus and yields a higher callus induction rate.展开更多
基金Funded by the National Natural Science Foundation of China(Nos.52278518 and 51938011)the Natural Science Foundation of the Jiangsu Higher Education Institutions of China(No.24KJB560021)。
文摘Based on the split hopkinson pressure bar(SHPB)tests results,the cubic specimens have been numerically modeled in this paper to investigate the impact of key factors,such as the rise time,duration,and incident pulse shape,on achieving stress uniformity.After analysis,the paper provides actionable methods aimed at optimizing the conditions for stress uniformity within the cubic specimen.Finally,the lateral inertia effect of cubic specimen has been scrutinized to address the existing gap in this academic area.
基金Supported by Natural Science Foundation of HuBei Province(2022CFB299).
文摘This paper studies the problem of the spectral radius of the uniform hypergraph determined by the signless Laplacian matrix.The upper bound of the spectral radius of a uniform hypergraph is obtained by using Rayleigh principle and the perturbation of the spectral radius under moving the edge operation,and the extremal hypergraphs are characterized for both supertree and unicyclic hypergraphs.The spectral radius of the graph is generalized.
文摘At our school,we have to wear uniforms every day.The problem is that all my classmates think the uniforms are ugly.We think young people should look smart,because①we would like to wear our own clothes.Our teachers think that if we do that,we will concentrate much②on our clothes than our studies.We don't agree.
基金Supported by the Liaoning Provincial Natural Science Foundation(Grant No.2023-MSBA-008)Unveiling and Commanding Program of Liaoning Province(Grant No.2022JH1/10800080)the Fundamental Research Funds for the Central Universities(Grant No.DUT24MS008).
文摘The double-sided lapping process is extensively employed in the manufacturing of wafers,optical windows,and seal rings due to its high efficiency and ability to achieve precise flatness.However,limited research has explored the thickness uniformity among different workpieces after double-sided lapping,and the underlying mechanism remains unclear.To address the demand for higher precision,this paper first analyzed the relative kinematic model between the workpiece and the lapping plate to clarify the causes of thickness variations among workpieces after double-sided lapping.Subsequently,a finite element method(FEM)model was developed to account for the pressure distribution on the workpiece surfaces at the initial stage of the process.The results indicate that the number of workpieces influences the final thickness variation.Then,various sets of thin copper plates with different thicknesses were lapped,and the findings revealed that five copper plates processed simultaneously exhibited more uniform thickness compared to the three plates.The experimental results align well with the theoretical analysis.Ultimately,a thickness variation of less than 6μm was achieved on five copper plates measuringΦ100×2.9 mm.This study presents a comprehensive analysis of the mechanisms influencing thickness uniformity in the double-sided lapping process and provides practical guidelines for optimizing the process to achieve stringent precision standards in industrial applications.
基金supported by the National Natural Science Foundation of China(No.62206143)the Key Research and Development and Promotion Special Project in Henan Province(Nos.222102210141 and 232102211015)。
文摘In this study,we present a unified sparsity-driven framework that significantly enhances motion deblurring performance by integrating two key components:a custom-designed dataset and a low-rank module(LRM).This framework leverages the inherent sparsity of per-pixel blur kernels to bolster both deblurring accuracy and model interpretability.Firstly,we propose an adaptive-basis decomposition-based deblurring(ADD)approach,which constructs a tailored training dataset to enhance the generalization capacity of the deblurring network.The ADD framework adaptively decomposes motion blur into sparse basis elements,effectively addressing the intricacies associated with non-uniform blurs.Secondly,an LRM is proposed to improve the interpretability of deblurring models as a plug-and-play module,primarily designed to identify and harness the intrinsic sparse features in sharp images.A series of ablation studies have been conducted to substantiate the synergistic advantages of combining the proposed ADD with the LRM for overall improvement in deblurring efficacy.Subsequently,we empirically demonstrate through rigorous experimentation that incorporating the LRM into an existing Uformer network leads to substantial enhancement in reconstruction performance.This integration yields a sparsity-guided low-rank network(SGLRN).Operating under the overarching principle of sparsity,SGLRN consistently outperforms state-of-the-art methods across multiple standard deblurring benchmarks.Comprehensive experimental results,assessed through quantitative metrics and qualitative visual evaluations,provide compelling evidence of its effectiveness.The overall deblurring results are available at Google Drive.
基金support of Natural Science Foundation of China(Grant No.52108324,No.52008207,and No.52108298)for conducting this study.
文摘The mineralization process of microbial-induced calcium carbonate precipitation(MICP)is influenced by many factors,and the uniformity of the calcium carbonate precipitation has become the main focus and challenge for MICP technology.In this study,the uniformity of the saturated calcareous sand treated with MICP was in-vestigated through one-dimensional calcareous sand column tests and model tests.The coefficient of variation was employed in one-dimensional sand column tests to investigate the impact of injection rate,cementation solution concentration,and number of injection cycles on the uniformity of the MICP treatment.Additionally,model tests were conducted to investigate the impact of injection pressure and methods on the treatment range and uniformity under three-dimensional seepage conditions.Test results demonstrate that the reinforcement strength and uniformity are significantly influenced by the injection rate of the cementation solution,with a rate of 3 mL/min,yielding a favorable treatment effect.Excessive concentration of the cementation solution can lead to significant non-uniformity and a reduction in the compressive strength of MICP-treated samples.Conversely,excessively low concentrations may result in decreased bonding efficiency.Among the four considered con-centrations,0.5 mol/L and 1 mol/L exhibit superior reinforcing effects.The morphological development of calcareous sandy foundation reinforcement is associated with the spatial distribution pattern of the bacterial solution,exhibiting a relatively larger reinforcement area in proximity to the lower region of the model and a gradually decreasing range towards the upper part.Under three-dimensional seepage conditions,in addition to the non-uniform radial cementation along the injection pipe,there is also vertical heterogeneity of cementation along the length of the injection pipe due to gravitational effects,resulting in preferential deposition of calcium carbonate at the lower section,The application of injection pressure and a double-pipe circulation injection method can mitigate the accumulation of bacterial solution and cementation solution at the bottom,thereby improving the reinforcement range and uniformity.
文摘On the morning of May 31st,the parallel forum"Seeking Harmony without Uniformity in Mutual Learning:Diversity of Civilisations from the Sinologists'Perspective"was held in Dunhuang.The forum was hosted by the Chinese Association for International Understanding and organised by Beijing Language and Culture University.Leading Sinologists and Chinese culture researchers from Europe,Asia and Latin America gathered to discuss the theme of civilisational diversity and explore pathways for coexistence and mutual enrichment.
基金Funded by the Key Research and Development Program of Shandong Province(No.2020JMRH0101)。
文摘Ceramic hollow spheres have great potential for deep-sea applications.However,the irregularity of the conventional molding process,among other reasons,results in low wall thickness uniformity of hollow spheres.To solve this problem,in this work,we developed a biaxial rotation grouting process for deep-sea ceramic hollow buoyancy spheres,which improves the drawbacks of the traditional rotary grouting method that results in poor wall thickness uniformity of the hollow spheres due to its irregular rotational processing.In this paper,an experimental study was carried out to investigate the effects of different rotational methods,rotational speeds,rotational time,solid phase content,etc.on the wall thickness uniformity of ceramic hollow spheres.The results show that the hollow floating balls prepared by the biaxial rotation method have the lowest wall thickness standard deviation(0.04)when the rotation speed is 60 rpm,the molding time is 8 min,and the solid phase content is 70 wt%.After the hydrostatic pressure test of 120 MPa,the hydrostatic compressive strength of hollow spheres prepared by the biaxial rotation method was increased by 31.67%compared with that of the traditional process.
基金financially supported by the National Key Research and Development Program of China(No.2020YFB1713500)the Natural Science Foundation of Henan Province(No.242300420021)Open Fund of State Key Laboratory of Advanced Refractories(No.SKLAR202210)
文摘Polyvinylidene fluoride(PVDF)/garnet composite polymer electrolytes(CPEs) have shown great potential in the development of solid-state lithium metal batteries(SSLMBs) due to their excellent flexibility, high ionic conductivity and superior mechanical strength.However, uneven dispersion of garnet fillers in CPEs would lead to deterioration of lithium metal batteries(LMBs) performance and severely limit their widespread application. Considering the rapidly growing research of addressing above-mentioned issue, herein, recent progress in the design and fabrication of uniformly dispersed fillers in PVDF/garnet CPEs for high-performance SSLMBs is summarized. We firstly analyze the mechanism for the aggregation of inorganic fillers, and provide a detailed introduction to the strategies for solving the uneven dispersion of nanoparticles in solid electrolytes. Moreover, we also comprehensively summarize their applications in PVDF/garnet electrolytes and their impact on the electrochemical performance of SSLMBs. Finally, the application challenges and future prospects of PVDF/garnet CPEs in SSLMBs were also proposed to promote their further development. It is anticipated that this review could inspire ongoing research interest in rational designing and fabricating novel CPEs for high-performance SSLMBs.
文摘Characteristics of heat transfer and flow of Newtonian and non-Newtonian fluids through porous walls and in porous media are studied due to their wide range of applications including geothermal reservoirs,heat exchangers,marine propulsion,and aerodynamics.The current study investigates the characteristics of heat transport in a reactive third-grade fluid,moving through permeable parallel plates,with uniform suction/injection velocity.The two permeable,parallel plates are maintained at the same,constant temperature.After being transformed into its dimensionless equivalent,governing equations are solved by employing the Least Squares Method(LSM).The LSM results are further validated with numerical solutions for temperature and velocity.The impact of cross-flow Reynolds number,Peclet number,heat generation parameter,non-Newtonian parameter,and Brinkman number on entropy generation,velocity,temperature,and Bejan number are investigated.Theresults indicate that temperature distribution is significantly influenced by the third-grade fluid parameter.The maximum temperature drops from almost 0.12 to 0.10 as the third-grade fluid parameter increases from0.05 to 0.4.When the cross-flow Reynolds number is raised from 0.05 to 3,the maximum temperature drops from 0.12 to around 0.09.Temperature is strongly influenced by the heat generation parameter.A greater understanding of the thermal characteristics necessary for the design of a variety of systems,such as heat exchangers,marine propulsion,aerodynamic systems,etc.,may be gained from the findings of the current study.
基金supported by Ministry of Science and ICT,South Korea(RS‐2024‐00407282)National Research Foundation of Korea(RS‐2024‐00408156).
文摘The practical application of lithium(Li)metal batteries(LMBs)faces challenges due to the irreversible Li deposition/dissolution process,which promotes Li dendrite growth with severe parasitic reactions during cycling.To address these issues,achieving uniform Li‐ion flux and improving Li‐ion conductivity of the separator are the top priorities.Herein,a separator(PCELS)with enhanced Li‐ion conductivity,composed of polymer,ceramic,and electrically conductive carbon,is proposed to facilitate fast Li‐ion transport kinetics and increase Li deposition uniformity of the LMBs.The PCELS immobilizes PF6–anions with high adsorption energies,leading to a high Li‐ion transference number.Simultaneously,the PCELS shows excellent electrolyte wettability on both its sides,promoting rapid ion transport.Moreover,the electrically conductive carbon within the PCELS provides additional electron transport channels,enabling efficient charge transfer and uniform Li‐ion flux.With these advantages,the PCELS achieves rapid Li‐ion transport kinetics and uniform Li deposition,demonstrating excellent cycling stability over 100 cycles at a high current density of 12.0 mA cm^(-2).Furthermore,the PCELS shows stable cycling performances in Li–S cell tests and delivers an excellent capacity retention of 95.45%in the Li|LiFePO_(4) full‐cell test with a high areal capacity of over 5.5 mAh cm^(-2).
基金supported by the National Nature Science Foundation of China(No.12172211)the National Key Research and Development Program of China(No.2019YFC1509800)。
文摘1 Introduction In highway construction,flled embankments are trapezoidal,and the ground is always improved by sand wells or columns.During embankment construction,because the width and height of the embankment are changing,a non-uniform load that varies with time and lateral location is applied to the underlying ground.The consolidation phenomenon under two-dimensional(2D)conditions will keep pace with the construction of the embankment.In addition,because of evaporation and rainfall,the soils are mostly unsaturated.Therefore,it is meaningful to research the consolidation properties of unsaturated ground under non-uniform loading.
基金Project Research Infrastructure for Campus-based Laboratories at the University of Rijeka(RC.2.2.06-0001)funded by the Ministry of Science,EducationSports of the Republic of Croatia.This project has been co-funded by the European Fund for Regional Development(ERDF)The support is gratefully acknowledged.This research was partially supported by the project“Laboratory Research of Static and Cyclic Behavior at Landslide Activation”(uniri-tehnic-18-113)funded by the University of Rijeka,Croatia.
文摘In soil dynamics,cyclic tests on sands have been extensively studied over the past several decades.Among the natural materials most susceptible to strength loss due to earthquakes,sands are commonly tested under varying loading,frequency,and drainage conditions.Traditionally,it has been assumed that pore pressure increases with constant strength loss once the threshold for pore pressure build-up is reached.However,recent studies have revealed that at small strains,the material initially hardens despite the generation of pore pressure.This paper presents the response and degradation of uniformly graded Drava River sand(DrOS018),similar to well-known sands such as Toyoura,Nevada or Ottawa sands,and the initial hardening phenomena that occur around threshold strains.Tests were conducted using a triaxial cyclic device at three relative densities and cell pressures(100 kPa,200 kPa,and 400 kPa)under undrained conditions.Strain-controlled tests were conducted at 0.1 Hz and 0.05 Hz using sinusoidal loading,with samples prepared by under-compaction.After crossing the threshold,the sand initially shows hardening(degradation index greater than 1)with up to a 35%increase in pore pressure,followed by strength degradation at higher strains.This study is critical for seismic design and safety,particularly for fully saturated sands in coastal and high water table areas.The findings enhance our understanding of liquefaction potential and site response,aiding more informed engineering practices by contributing to enhanced knowledge in soil dynamics and improved predictive models.The results support effective mitigation strategies and infrastructure resilience in earthquake-prone regions such as Croatia.
基金supported by the 2022 Fujian Provincial Young and Middle-aged Teacher Education and Research Project(Science and Technology)(No.JAT220468)the Xiamen Natural Science Foundation(No.3502Z20227334).
文摘At present,the naked-eye three-dimensional(3D)display technology still has some drawbacks,such as low brightness uniformity,high crosstalk,low light efficiency,short viewing distance,and the manufacturing is difficulty.Based on the principle of naked-eye 3D display and the Fresnel optical theory,this paper designs a Fresnel lens array and the star-shaped liquid crystal display(LCD)switch of unit LCD screen to achieve low-crosstalk and high brightness uniformity for the autostereoscopic 3D display.The unit parameters of a 139.7 cm 4K model autostereoscopic 3D displayer are provided and they are optimized by the TracePro software.The results show that when the pitch of the Fresnel lens on the exit surface is 0.304 mm,the width of each serration of Fresnel lens is 0.0234 mm,the length of the Fresnel lens is 2.87 mm,and the center height of star-shaped LCD switch is 0.030 mm,the center length is 0.040 mm,the width of star-shaped LCD switch is 0.050 mm,and the image crosstalk is less than 2%when the viewing distance is 2.50 m.The problem on the brightness of the image in different positions is improved.
基金financially supported by the National Natural Science Foundation of China(Nos.22468029,52274408,52204314)the Major Science and Technology Projects in Yunnan Province(No.202402AF080005)+1 种基金Yunnan Fundamental Research Projects(No.202201AW070014)the Program for Innovative Research Team in the University of ministry of Education of China(No.IRT_17R48)
文摘Ultrafine metal nanoparticles are crucial for various applications,such as energy storage,catalysis,electronics,and biomedicine,owing to their high surfaceto-volume ratio and unique electronic properties.However,conventional nanoparticle synthesis methods often face challenges like irregular shapes and agglomeration,leading to compromised functionality.To address these challenges,this paper introduces a novel,rapid,high-temperature thermal radiation heating for the ultrafast synthesis and dispersion of metal nanoparticles.Utilizing the heating properties of carbon materials,the direct Joule heating generated by them rises to 1800-2000 K within~200 ms,followed by cooling to room temperature at a rate of 2×10^(3)K s^(-1).
基金supported by the National Natural Science Foundation of China(No.62071365)the Key Research and Development Program of Shaanxi Province(No.2017ZDCXL-GY-06-02).
文摘To improve the quality of the illumination distribution,one novel indoor visible light communication(VLC)system,which is jointly assisted by the angle-diversity transceivers and simultaneous transmission and reflection-intelligent reflecting surface(STAR-IRS),has been proposed in this work.A Harris Hawks optimizer algorithm(HHOA)-based two-stage alternating iteration algorithm(TSAIA)is presented to jointly optimize the magnitude and uniformity of the received optical power.Besides,to demonstrate the superiority of the proposed strategy,several benchmark schemes are simulated and compared.Results showed that compared to other optimization strategies,the TSAIA scheme is more capable of balancing the average value and variance of the received optical power,when the maximal ratio combining(MRC)strategy is adopted at the receiver.Moreover,as the number of the STAR-IRS elements increases,the optical power variance of the system optimized by TSAIA scheme would become smaller while the average optical power would get larger.This study will benefit the design of received optical power distribution for indoor VLC systems.
基金support from the National Natural Science Foundation of China(22088101,21733003,22365021,22305132)the Inner Mongolia Autonomous Region“Grassland Talents”Project(2024098)+3 种基金the Inner Mongolia Natural Science Foundation Youth Fund(2023QN02014)The Local Talent Project of Inner Mongolia(12000-15042222)the Basic Research Expenses Supported under 45 Years Old of Inner Mongolia(10000-23112101/036)the“Young Academic Talents”Program of Inner Mongolia University 23600-5233706.
文摘As a class of crystalline porous materials,metal-organic frameworks(MOFs)have shown unique advantages in the fields of catalysis,gas storage and separation,but their inherent microporous structure(pore diameter<2 nm)severely limits their application in scenarios such as macromolecular mass transfer and so on.In order to overcome this re-striction,mesoporous MOFs(meso-MOFs)with a larger aperture(2-50 nm)have attracted much attention due to their potential applications in biological macromolecular catalysis,energy storage and other fields.To date,how to accurately regulate its mesopore topology and pore ordering still faces important technical challenges.
基金Projects(51204053,51074048,51204048)supported by the National Natural Science Foundation of ChinaProject(20110491518)supported by China Postdoctoral Science FoundationProject(2012CB619506)supported by the National Basic Research Program of China
文摘The effect of forging passes on the refinement of high purity aluminum during multi-forging was investigated. The attention was focused on the structure uniformity due to deformation uniformity and the grain refinement limitation with very high strains. The results show that the fine grain zone in the center of sample expands gradually with the increase of forging passes. When the forging passes reach 6, an X-shape fine grain zone is initially formed. With a further increase of the passes, this X-shape zone tends to spread the whole sample. Limitation in the structural refinement is observed with increasing strains during multi-forging process at the room temperature. The grains size in the center is refined to a certain size （110 μm as forging passes reach 12, and there is no further grain refinement in the center with increasing the forging passes to 24. However, the size of the coarse grains near the surface is continuously decreased with increasing the forging passes to 24.
基金Supported by International Collaboration Research Program~~
文摘[Objective]This study was to optimize callus induction medium for Schisandga chinensis Baill.[Method]Using callus induction rate as an indicator,uniform design was employed to optimize hormone combination at poly-factors and poly-levels for callus induction from Schisandga chinensis Baill.[Results]Optimal hormone combinations depended on different explants：optimum medium for both tender leaf and petiole was MS ＋3 mg/L 6-BA,for stem segment was MS ＋3 mg/L 6-BA ＋0.6 mg/L NAA.[Conclusion]Uniform design is a time-saving and convenient method for the optimum medium for callus and yields a higher callus induction rate.
