The growing demands for energy storage systems,electric vehicles,and portable electronics have significantly pushed forward the need for safe and reliable lithium batteries.It is essential to design functional separat...The growing demands for energy storage systems,electric vehicles,and portable electronics have significantly pushed forward the need for safe and reliable lithium batteries.It is essential to design functional separators with improved mechanical and electrochemical characteristics.This review covers the improved mechanical and electrochemical performances as well as the advancements made in the design of separators utilizing a variety of techniques.In terms of electrolyte wettability and adhesion of the coating materials,we provide an overview of the current status of research on coated separators,in situ modified separators,and grafting modified separators,and elaborate additional performance parameters of interest.The characteristics of inorganics coated separators,organic framework coated separators and inorganic-organic coated separators from different fabrication methods are compared.Future directions regarding new modified materials,manufacturing process,quantitative analysis of adhesion and so on are proposed toward next-generation advanced lithium batteries.展开更多
Excellent detonation performances and low sensitivity are prerequisites for the deployment of energetic materials.Exploring the underlying factors that affect impact sensitivity and detonation performances as well as ...Excellent detonation performances and low sensitivity are prerequisites for the deployment of energetic materials.Exploring the underlying factors that affect impact sensitivity and detonation performances as well as exploring how to obtain materials with desired properties remains a long-term challenge.Machine learning with its ability to solve complex tasks and perform robust data processing can reveal the relationship between performance and descriptive indicators,potentially accelerating the development process of energetic materials.In this background,impact sensitivity,detonation performances,and 28 physicochemical parameters for 222 energetic materials from density functional theory calculations and published literature were sorted out.Four machine learning algorithms were employed to predict various properties of energetic materials,including impact sensitivity,detonation velocity,detonation pressure,and Gurney energy.Analysis of Pearson coefficients and feature importance showed that the heat of explosion,oxygen balance,decomposition products,and HOMO energy levels have a strong correlation with the impact sensitivity of energetic materials.Oxygen balance,decomposition products,and density have a strong correlation with detonation performances.Utilizing impact sensitivity of 2,3,4-trinitrotoluene and the detonation performances of 2,4,6-trinitrobenzene-1,3,5-triamine as the benchmark,the analysis of feature importance rankings and statistical data revealed the optimal range of key features balancing impact sensitivity and detonation performances:oxygen balance values should be between-40%and-30%,density should range from 1.66 to 1.72 g/cm^(3),HOMO energy levels should be between-6.34 and-6.31 eV,and lipophilicity should be between-1.0 and 0.1,4.49 and 5.59.These findings not only offer important insights into the impact sensitivity and detonation performances of energetic materials,but also provide a theoretical guidance paradigm for the design and development of new energetic materials with optimal detonation performances and reduced sensitivity.展开更多
Nano-scale CuF_(2) with superior electrochemical activity was successfully prepared by a mixed solvent co-precipitation method.The SEM and TEM analyses demonstrated that the methanol concentration had a pronounced eff...Nano-scale CuF_(2) with superior electrochemical activity was successfully prepared by a mixed solvent co-precipitation method.The SEM and TEM analyses demonstrated that the methanol concentration had a pronounced effect on both the particle size and the extent of agglomeration.With the increase in methanol content,the particle size and agglomeration of CuF_(2) decreased first and then increased.When the volume ratio of methanol to deionized water was 1:1,the CuF_(2) particles exhibited the smallest size and the lowest degree of agglomeration.CuF_(2) synthesized with 50%methanol exhibited superior electrochemical performances with a voltage plateau above 3 V and a 1st discharge capacity of 525.8 mAh·g^(-1) at 0.01 C due to the synergistic influence of the particle size and dispersion.The analysis results using electrochemical impedance spectroscopy(EIS)and constant current intermittent titration technique(GITT)affirmed the addition of methanol was beneficial for promoting Li+diffusion and accelerating electrochemical reaction kinetics of CuF_(2).展开更多
Foamed concrete has been used to address the issue of differential settlement in high-speed railway subgrades in China.However,to enhance crack resistance,reinforcement is still necessary,and further research is requi...Foamed concrete has been used to address the issue of differential settlement in high-speed railway subgrades in China.However,to enhance crack resistance,reinforcement is still necessary,and further research is required to better understand the performance of foamed concrete in subgrade applications.To this end,a series of tests—including uniaxial compres-sive and dynamic triaxial tests—were conducted to comprehensively examine the effects of basalt fiber reinforcement on the mechanical properties of foamed concrete with densities of 700 and 1000 kg/m3.Additionally,a full-scale model of the foamed concrete subgrade was established,and simulated loading was applied.The diffusion patterns of dynamic stress and dynamic acceleration within the subgrade were explored,leading to the development of experimental formulas to calculate the attenuation coefficients of these two parameters along the depth and width of the subgrade.Furthermore,the dynamic displacement and cumulative settlement were analyzed to evaluate the stability of the subgrade.These findings provide valuable insights for the design and construction of foamed concrete subgrades in high-speed rail systems.The outcomes are currently under consideration for inclusion in the code of practice for high-speed rail restoration.展开更多
Sweet potato is one of the most important crops in Côte d’Ivoire. However, some constraints related to climate change limit its production. This study evaluated the agronomic and technological performances of ei...Sweet potato is one of the most important crops in Côte d’Ivoire. However, some constraints related to climate change limit its production. This study evaluated the agronomic and technological performances of eight varieties of orange-fleshed of sweet potato (Ipomoea batatas (L.) to identify the most promising ones. The results show three groups of varieties with different agronomic performances. Group 1 composed of Irene and Vita is characterized by low production of small and large tuberous roots, low number of productive plants and low yield. Group 2 consisting mainly of Kabode is characterized by high production and weight of large tuberous roots as well as high yield. Group 3, composed of Tacha-2 Ininda, Ejumula Gloria, TIB-440060, CIP-199062-1, Bela bela is characterized by high production of small and large tuberous roots, high number of productive plants and average yield. The TIB-440060 variety has a recovery rate of 100%. The Irene, Kabode, Vita, Kabode varieties were resistant to viral and fungal diseases. In terms of technological quality, the TIB-440060 and CIP-199062-1 varieties have the best organoleptic qualities. Given the agronomic performances of the Kabode, TIB-440060 and CIP-199062-1 varieties, could be selected as the elites varieties and distributed to producers.展开更多
High-entropy materials(HEMs),an innovative class of materials with complex stoichiometry,have recently garnered consider-able attention in energy storage applications.While their multi-element compositions(five or mor...High-entropy materials(HEMs),an innovative class of materials with complex stoichiometry,have recently garnered consider-able attention in energy storage applications.While their multi-element compositions(five or more principal elements in nearly equiatom-ic proportions)confer unique advantages such as high configurational entropy,lattice distortion,and synergistic cocktail effects,the fun-damental understanding of structure-property relationships in battery systems remains fragmented across existing studies.This review ad-dresses critical research gaps by proposing a multidimensional design paradigm that systematically integrates synergistic mechanisms spanning cathodes,anodes,electrolytes,and electrocatalysts.We provide an in-depth analysis of HEMs’thermodynamic/kinetic stabiliza-tion principles and structure-regulated electrochemical properties,integrating and establishing quantitative correlations between entropy-driven phase stability and charge transport dynamics.By summarizing the performance benchmarking results of lithium/sodium/potassi-um-ion battery components,we reveal how entropy-mediated structural tailoring enhances cycle stability and ionic conductivity.Notably,we pioneer the systematic association of high-entropy effects to electrochemical interfaces,demonstrating their unique potential in stabil-izing solid-electrolyte interphases and suppressing transition metal dissolution.Emerging opportunities in machine learning-driven com-position screening and sustainable manufacturing are discussed alongside critical challenges,including performance variability metrics and cost-benefit analysis for industrial implementation.This work provides both fundamental insights and practical guidelines for advan-cing HEMs toward next-generation battery technologies.展开更多
As an improvement on the conventional two-layer electrode （active material layerlcurrent collector）, a novel sandwich-like three-layer electrode （conductive layerlactive material layertcurrent collector） for catho...As an improvement on the conventional two-layer electrode （active material layerlcurrent collector）, a novel sandwich-like three-layer electrode （conductive layerlactive material layertcurrent collector） for cathode material LiFePO4/C was introduced in order to improve its electrochemical performance. LiFePO4/C in the three-layer electrode exhibited superior rate capability in comparison with that in the two-layer electrode in accordance with charge-discharge examination. Cyclic voltammetry and electrochemical impedance spectroscopy indicated that Fe3＋/Fe2＋ redox couple for LiFePO4 in the three-layer electrode displayed faster kinetics, better reversibility and much lower charge transfer resistance than that in the two-layer electrode in electrochemical process. For three-layer electrode, the holes in the surface of active material layer were filled by smaller acetylene black grains, which formed electrical connections and provided more pathways to electron transport to/from LiFePO4/C particles exposed to the bulk electrolyte.展开更多
This article investigated the factors and mechanisms that affected the workability and mechanical properties of cement paste incorporating nano-TiO_(2).The findings indicated that,for nano-TiO_(2)aqueous solution conc...This article investigated the factors and mechanisms that affected the workability and mechanical properties of cement paste incorporating nano-TiO_(2).The findings indicated that,for nano-TiO_(2)aqueous solution concentrations of 3%,6%,9%,and 12%,the optimal dispersion effect was achieved with an ultrasonic dispersion time of 20 minutes.Specifically,at a 6%nano-TiO_(2)content,both the workability and mechanical performance of the cement paste were enhanced.Furthermore,while nano-TiO_(2)did not alter the types of hydration products present in the cement paste,it did increase the amount of C-S-H gels.This enhancement was attributed to a higher number of nucleation sites for hydration products,which promoted hydration and reduced the porosity of the cement paste.展开更多
The oscillating hydrofoil represents a promising technology for harvesting energy from tidal currents.While previous research has primarily focused on oscillating hydrofoils utilizing a fully activated control strateg...The oscillating hydrofoil represents a promising technology for harvesting energy from tidal currents.While previous research has primarily focused on oscillating hydrofoils utilizing a fully activated control strategy,the industry predominantly employs a semi-activated control strategy in existing tidal current energy converters.It is essential to identify the differences in predicted energy-harvesting performance between these two controlling strategies through experimental modeling or numerical studies.Furthermore,the suitability of the fully activated control strategy in predicting the energy-harvesting capabilities of oscillating hydrofoils is evaluated.The 2D numerical models of hydrofoil based on fully activated and semi-activated control strategies have been developed and validated.The amplitudes of heaving and pitching movements for the fully activated hydrofoil are determined to match those of the semi-activated hydrofoil.The results show that the main difference between the two control strategies lies in the phase shift occurring between the pitching and heaving motions.This phase shift affects the lift force and its coordination with the heaving velocity,which in turn affects the power output.Notably,the maximum relative efficiency difference obtained between the fully activated and semi-activated control strategies can reach 191%.展开更多
Coating techniques are efficient routes to modify surface property of composite membranes for enhanced membrane separations.However,it remains challenge to deposit continuous inorganic layers on hollow fiber substrate...Coating techniques are efficient routes to modify surface property of composite membranes for enhanced membrane separations.However,it remains challenge to deposit continuous inorganic layers on hollow fiber substrates.This study combines surface segregation with physical vapor deposition(PVD)to construct intensified TiO_(2)layers on polyether sulfone(PES)hollow fiber substrates.During membrane fabrication,polyethylene-polypropylene glycol(F127)is used as surface segregation agent in casting solution,which enables PES hollow fibers with abundant hydroxy groups,thus improving the compatibility between PES and vaporized TiO_(2).The obtained PES/F127@TiO_(2)membranes exhibit tight TiO_(2)layers with tunable thickness,high mechanical strength,narrowed pore size and enhanced hydrophilicity.Moreover,the optimized PES/F127@TiO_(2)membranes show competitive antifouling performances in water treatment,with a water permeability up to 97 L·m^(-2)·h^(-1)·bar^(-1)and bovine serum albumin(BSA)rejection of~99%.This work is expected to provide a material design idea to deposit functional layers on polymers for fortified performances.展开更多
The behavior of single-phase flow and conjugate heat transfer in micro-channel heat sinks(MCHS)subjected to auniform heat flux is investigated by means of numerical simulations.Various geometrical configurations areex...The behavior of single-phase flow and conjugate heat transfer in micro-channel heat sinks(MCHS)subjected to auniform heat flux is investigated by means of numerical simulations.Various geometrical configurations areexamined,particularly,the combinations of rectangular solid and perforated blocks,used to create a disturbancein the flow.The analysis focuses on several key aspects and related metrics,including the temperature distribution,the mean Fanning friction factor,the pressure drop,the Nusselt number,and the overall heat transfer coefficientacross a range of Reynolds numbers(80–870).It is shown that the introduction of such blocks significantlyenhances the heat transfer performances of the MCHS compared to the straight-through flow channel.Specifically,a case is found where the Nusselt number increases by 2.3 times relative to the reference case.The integrationof perforated blocks facilitates the generation of vorticity within the channel,promoting the mixing of coldand hot fluids.Notably,MCHS incorporating perforated rectangular blocks exhibit more pronounced heat transferbenefits at Reynolds numbers smaller than 400.展开更多
Designing and fabricating high-performance photovoltaic devices have remained a major challenge in organic solar cell technologies. In this work, the photovoltaic performances of BTBPD-PC61BM system were theoretically...Designing and fabricating high-performance photovoltaic devices have remained a major challenge in organic solar cell technologies. In this work, the photovoltaic performances of BTBPD-PC61BM system were theoretically investigated by means of density functional theory calculations coupled with the Marcus charge transfer model in order to seek novel photovoltaic systems. Moreover, the hole-transfer properties of BTBPD thin-film were also studied by an amorphous cell with 100 BTBPD molecules. Results revealed that the BTBPD- PC61BM system possessed a middle-sized open-circuit voltage of 0.70 V, large short-circuit current density of 16.874 mA/cm2, large fill factor of 0.846, and high power conversion effi- ciency of 10%. With the Marcus model, the charge-dissociation rate constant was predicted to be as fast as 3.079×10^13 s^-1 in the BTBPD-PC61BM interface, which was as 3-5 orders of magnitude large as the decay （radiative and non-radiative） rate constant （108-10^10 s^-1）, indicating very high charge-dissociation efficiency （-100%） in the BTBPD-PC61BM system. Furthermore, by the molecular dynamics simulation, the hole mobility for BTBPD thin-film was predicted to be as high as 3.970× 10^-3 cm^2V^-1s^-1, which can be attributed to its tight packing in solid state.展开更多
The collecting performances of N-dodecylethylene-diamine （ND） to quartz and hematite were studied via single mineral flotation. Experimental results show that ND has stronger collecting ability to quartz than hemati...The collecting performances of N-dodecylethylene-diamine （ND） to quartz and hematite were studied via single mineral flotation. Experimental results show that ND has stronger collecting ability to quartz than hematite. Different floatability of quartz and hematite was presented in the existence of depressant. Compared with lauryl amine, ND has stronger collecting performances to quartz. Satisfied separation result of artificially mixed sample was acquired with iron grade of concentrate of 59.92% and iron recovery of 88.85% when pulp pH value was 7.27 with 41.7 mg/L collector and 3.33 mg/L starch. Polar group properties calculation results indicated that ND has stronger collecting capability and better selectivity than lauryl amine. Measurement results of zeta-potentials and infrared spectrum showed that hydrogen bonding adsorption and electrostatic adsorption occur between the surface of ND and quartz.展开更多
[Objective] The aim of this study was to investigate the correlation between blood protein polymorphism of red steppe and its performance.[Method]Two blood protein polymorphic loci were detected in transferring(Tf)and...[Objective] The aim of this study was to investigate the correlation between blood protein polymorphism of red steppe and its performance.[Method]Two blood protein polymorphic loci were detected in transferring(Tf)and posttremsferr(Ptf)from thirteen red steppes and eighteen hybrid of limousin and red steppe by polyacrylamide gel electrophoresis.[Result]Tf and Ptf were controlled by three and two alleles respectively.[Conclusion]The variance analysis of blood protein polymorphic loci and its performance indicates that two protein loci have a positive or negative correlation with some traits of red steppe and the improved limousin cattle population.展开更多
In order to investigate the influences of the stoichiometric ratio of La/Mg （increasing La and decreasing Mg on the same mole ratio） on the structure and electrochemical performances of the La-Mg-Ni-based A2B7-type ...In order to investigate the influences of the stoichiometric ratio of La/Mg （increasing La and decreasing Mg on the same mole ratio） on the structure and electrochemical performances of the La-Mg-Ni-based A2B7-type electrode alloy, the as-cast and the annealed ternary Lao.8＋xMgo.2_xNi3.5 （x=0-0.05） electrode alloys were prepared. The characterization of electrode alloys by X-ray diffraction （XRD） and scanning electron microscopy （SEM） shows that all the as-cast and the annealed alloys hold two major phases of （La,Mg）2Ni7 and LaNi5 as well as a residual phase of LaNi3. Moreover, the increase of La/Mg ratio brings on a decline of （La,Mg）2Ni7 phase and a rise of LaNi5 and LaNi3 phases. The variation of La/Mg ratio gives rise to an evident change of the electrochemical performances of the alloys. The discharge capacities of the as-cast and the annealed alloys evidently decrease with growing the La/Mg ratio, while the cycle stabilities of the alloys visibly augment under the same condition. Furthermore, the high rate discharge ability （HRD）, the electrochemical impedance spectrum （EIS）, the Tafel polarization curves, and the potential step measurements all indicate that the electrochemical kinetic properties of the alloy electrodes increase with the La/Mg ratio rising.展开更多
This study was carried out to unravel the mechanism of reductions in production performances in high stocking density geese flocks during summer months in ＂geese-fish＂ production system. Experiment 1 observed the wa...This study was carried out to unravel the mechanism of reductions in production performances in high stocking density geese flocks during summer months in ＂geese-fish＂ production system. Experiment 1 observed the water bacterial growth, lipopolysaccharde concentrations in water and geese blood, and geese reproductive performances from summer to winter, in two flocks with varying on water stocking densities. Results showed that counts of total bacteria, Escherichia coli and Salmonella in water, as well as water and geese plasma LPS concentrations, exhibited a tendency decreasing from the highest levels in summer, to intermediate levels in autumn, and to the lowest values in winter. Such seasonal decreases in bacteria and LPS concentrations were associated with similar seasonal decreases in embryo mortality during incubation. In addition, embryos dead or showing development retardation by day 25 of incubation contained copious LPS in allantoic fluid, in contrast to the negligible amount in normal developing embryos. Raising on water stocking density elevated bacteria counts, LPS concentrations in water and geese plasma, and decreased egg fertility but increased embryo mortality during incubation. In experiment 2, exogenous LPS treatment to the geese depressed egg laying, reduced egg hatchability, caused sickness behavior in the goslings hatched. In experiment 3, exogenous LPS directly administered to day 8 and 18 embryos during incubation dose dependently increased mortality and decreased hatchability, and caused sickness behavior in the goslings hatched. It is concluded that the raising on water geese stocking density stimulates pathogenic bacteria growth in water, which via LPS contamination impaires embryo development in incubation and therefore reduces geese reproductive performance and gosling quality during the hot summer months.展开更多
By using Bayesian and multiple Bayesian method, the failure probability, reliability and mean time to failure(MTTF) of series system with cold standby units are estimated. At last, we compare the two estimators by mea...By using Bayesian and multiple Bayesian method, the failure probability, reliability and mean time to failure(MTTF) of series system with cold standby units are estimated. At last, we compare the two estimators by means of Monte_Carlo simulation.展开更多
Hydrogen storage properties of 2LiNH2-MgH2 system were improved by adding lanthanum hydride （LaH3）, and the role of LaH3 in hydrogen sorption process of Li-Mg-N-H system was investigated. Temperature programmed sorp...Hydrogen storage properties of 2LiNH2-MgH2 system were improved by adding lanthanum hydride （LaH3）, and the role of LaH3 in hydrogen sorption process of Li-Mg-N-H system was investigated. Temperature programmed sorption results showed that the addition of lanthanum hydride reduced the dehydriding/hydriding onset temperature of 2LiNH2-MgH2 system by at least 15 K. Moreover, A 0.053 wt.%/min average rate was determined for the hydrogen desorption of 2LiNH2-MgH2-0.05LaH3 composite, while it was only 0.035 wt.%/min for 2LiNH2-MgH2 system. Hydrogen absorption capacity increased from 1.62 wt.% to 2.12 wt.% within 200 min by adding LaH3 into 2LiNH2-MgH2 system at 383 K. In the dehydrogenation of 2LiNH2-MgH2-0.05LaH3 composite, LaH2 transferred to LaN phase, which reversed to LaH2 in the following hydrogen adsorption process. The reversible reaction of LaH2 ef- fectively promoted the hydrogen sorption of Li-Mg-N-H system. Moreover, the homogenous distribution of fine La hydride was fa- vorable to improving effect of lanthanum hydride.展开更多
Al coated NdFeB magnets obtained by vacuum evaporation technique were densified by high energy ball milling method.The surface morphology,metal composition and micro structure of the coatings were characterized by sca...Al coated NdFeB magnets obtained by vacuum evaporation technique were densified by high energy ball milling method.The surface morphology,metal composition and micro structure of the coatings were characterized by scanning electron microscopy,X-ray diffraction and X-ray photoelectron spectroscopy,respectively.The anticorrosive properties were investigated by potentiodynamic polarization curves and neutral salt spray test.The pores in the Al coatings of columnar crystals(Al) induced by the evaporation technique,were apparently filled in the following ball milling process,leading to the densification of Al coatings and the evident improvement of the anticorrosive performances.When treated with ball milling for 30 min,the sample achieves the best anticorrosive performances with the self-corrosion potential of-0.87 V,self-corrosion current density of 1.65 μA/cm^(2) and the neutral salt spray(NSS) time of 144 h(red rust).The improvement of the anticorro sive performances of vacuum evaporated Al coating mainly lies in the densification effect of the coating,which depends on different loading conditions of ball milling process.展开更多
In this study, two-dimensional MXene (Ti3 C2 Tx ) was employed to modify the interface of carbon fiber-reinforced polyetherketoneketone (CF/PEKK) composites, in order to simultaneously improve the electromagnetic inte...In this study, two-dimensional MXene (Ti3 C2 Tx ) was employed to modify the interface of carbon fiber-reinforced polyetherketoneketone (CF/PEKK) composites, in order to simultaneously improve the electromagnetic interference (EMI) shielding performances and mechanical properties. The obtained CF/PEKK composites possessed outstanding EMI and mechanical performances, as anticipated. Specifically, the CF/PEKK composites modified with MXene at 1 mg mL–1 exhibited an excellent EMI shielding effectiveness of 65.2 dB in the X-band, a 103.1% enhancement compared with the unmodified CF/PEKK composites. The attractive EMI shielding performances of CF/PEKK composites originated from enhanced ohmic losses and multiple reflections of electromagnetic waves with the help of the MXene and CF layers. In addition, CF/PEKK composites achieved the best mechanical properties by optimizing the dispersion concentration of MXene to 0.1 mg mL–1 . The flexural strength, flexural modulus, and interlaminar shear strength of CF/PEKK composites reached 1127 MPa, 81 GPa, and 89 MPa, which were 28.5%, 9.5%, and 29.7% higher than that of the unmodified CF/PEKK composites, respectively. Such improvement in mechanical properties could be ascribed to the comprehensive effect of mechanical interlocking, hydrogen bonds, and Van der Waals forces between the introduced MXene and CF, PEKK, respectively.展开更多
基金the Center of Lithium Battery Membrane Materials jointly established by School of Chemistry and Chemical Engineering of Huazhong University of Science and Technology and Shenzhen Senior Technology Material Co.Ltd.,the National Natural Science Foundation of China(52020105012,52303084)the Young Scientists Fund of Natural Science Foundation of Hubei Province(2023AFB220)for the support of this work.
文摘The growing demands for energy storage systems,electric vehicles,and portable electronics have significantly pushed forward the need for safe and reliable lithium batteries.It is essential to design functional separators with improved mechanical and electrochemical characteristics.This review covers the improved mechanical and electrochemical performances as well as the advancements made in the design of separators utilizing a variety of techniques.In terms of electrolyte wettability and adhesion of the coating materials,we provide an overview of the current status of research on coated separators,in situ modified separators,and grafting modified separators,and elaborate additional performance parameters of interest.The characteristics of inorganics coated separators,organic framework coated separators and inorganic-organic coated separators from different fabrication methods are compared.Future directions regarding new modified materials,manufacturing process,quantitative analysis of adhesion and so on are proposed toward next-generation advanced lithium batteries.
基金supported by the Fundamental Research Funds for the Central Universities(Grant No.2682024GF019)。
文摘Excellent detonation performances and low sensitivity are prerequisites for the deployment of energetic materials.Exploring the underlying factors that affect impact sensitivity and detonation performances as well as exploring how to obtain materials with desired properties remains a long-term challenge.Machine learning with its ability to solve complex tasks and perform robust data processing can reveal the relationship between performance and descriptive indicators,potentially accelerating the development process of energetic materials.In this background,impact sensitivity,detonation performances,and 28 physicochemical parameters for 222 energetic materials from density functional theory calculations and published literature were sorted out.Four machine learning algorithms were employed to predict various properties of energetic materials,including impact sensitivity,detonation velocity,detonation pressure,and Gurney energy.Analysis of Pearson coefficients and feature importance showed that the heat of explosion,oxygen balance,decomposition products,and HOMO energy levels have a strong correlation with the impact sensitivity of energetic materials.Oxygen balance,decomposition products,and density have a strong correlation with detonation performances.Utilizing impact sensitivity of 2,3,4-trinitrotoluene and the detonation performances of 2,4,6-trinitrobenzene-1,3,5-triamine as the benchmark,the analysis of feature importance rankings and statistical data revealed the optimal range of key features balancing impact sensitivity and detonation performances:oxygen balance values should be between-40%and-30%,density should range from 1.66 to 1.72 g/cm^(3),HOMO energy levels should be between-6.34 and-6.31 eV,and lipophilicity should be between-1.0 and 0.1,4.49 and 5.59.These findings not only offer important insights into the impact sensitivity and detonation performances of energetic materials,but also provide a theoretical guidance paradigm for the design and development of new energetic materials with optimal detonation performances and reduced sensitivity.
文摘Nano-scale CuF_(2) with superior electrochemical activity was successfully prepared by a mixed solvent co-precipitation method.The SEM and TEM analyses demonstrated that the methanol concentration had a pronounced effect on both the particle size and the extent of agglomeration.With the increase in methanol content,the particle size and agglomeration of CuF_(2) decreased first and then increased.When the volume ratio of methanol to deionized water was 1:1,the CuF_(2) particles exhibited the smallest size and the lowest degree of agglomeration.CuF_(2) synthesized with 50%methanol exhibited superior electrochemical performances with a voltage plateau above 3 V and a 1st discharge capacity of 525.8 mAh·g^(-1) at 0.01 C due to the synergistic influence of the particle size and dispersion.The analysis results using electrochemical impedance spectroscopy(EIS)and constant current intermittent titration technique(GITT)affirmed the addition of methanol was beneficial for promoting Li+diffusion and accelerating electrochemical reaction kinetics of CuF_(2).
基金support for this research from the Fundamental Research Funds for the National Natural Science Foundation of China (Grant Nos. 51978588, 52078434, and 52368065)the China Scholarship Council (Grant No. 202107000077)UKRI Engineering and Physical Science ResearchCouncil (EPSRC) for the financial sponsorship of Re4Rail project (Grant No. EP/Y015401/1)
文摘Foamed concrete has been used to address the issue of differential settlement in high-speed railway subgrades in China.However,to enhance crack resistance,reinforcement is still necessary,and further research is required to better understand the performance of foamed concrete in subgrade applications.To this end,a series of tests—including uniaxial compres-sive and dynamic triaxial tests—were conducted to comprehensively examine the effects of basalt fiber reinforcement on the mechanical properties of foamed concrete with densities of 700 and 1000 kg/m3.Additionally,a full-scale model of the foamed concrete subgrade was established,and simulated loading was applied.The diffusion patterns of dynamic stress and dynamic acceleration within the subgrade were explored,leading to the development of experimental formulas to calculate the attenuation coefficients of these two parameters along the depth and width of the subgrade.Furthermore,the dynamic displacement and cumulative settlement were analyzed to evaluate the stability of the subgrade.These findings provide valuable insights for the design and construction of foamed concrete subgrades in high-speed rail systems.The outcomes are currently under consideration for inclusion in the code of practice for high-speed rail restoration.
文摘Sweet potato is one of the most important crops in Côte d’Ivoire. However, some constraints related to climate change limit its production. This study evaluated the agronomic and technological performances of eight varieties of orange-fleshed of sweet potato (Ipomoea batatas (L.) to identify the most promising ones. The results show three groups of varieties with different agronomic performances. Group 1 composed of Irene and Vita is characterized by low production of small and large tuberous roots, low number of productive plants and low yield. Group 2 consisting mainly of Kabode is characterized by high production and weight of large tuberous roots as well as high yield. Group 3, composed of Tacha-2 Ininda, Ejumula Gloria, TIB-440060, CIP-199062-1, Bela bela is characterized by high production of small and large tuberous roots, high number of productive plants and average yield. The TIB-440060 variety has a recovery rate of 100%. The Irene, Kabode, Vita, Kabode varieties were resistant to viral and fungal diseases. In terms of technological quality, the TIB-440060 and CIP-199062-1 varieties have the best organoleptic qualities. Given the agronomic performances of the Kabode, TIB-440060 and CIP-199062-1 varieties, could be selected as the elites varieties and distributed to producers.
基金supported by National Natural Science Foundation of China(No.5227130161).
文摘High-entropy materials(HEMs),an innovative class of materials with complex stoichiometry,have recently garnered consider-able attention in energy storage applications.While their multi-element compositions(five or more principal elements in nearly equiatom-ic proportions)confer unique advantages such as high configurational entropy,lattice distortion,and synergistic cocktail effects,the fun-damental understanding of structure-property relationships in battery systems remains fragmented across existing studies.This review ad-dresses critical research gaps by proposing a multidimensional design paradigm that systematically integrates synergistic mechanisms spanning cathodes,anodes,electrolytes,and electrocatalysts.We provide an in-depth analysis of HEMs’thermodynamic/kinetic stabiliza-tion principles and structure-regulated electrochemical properties,integrating and establishing quantitative correlations between entropy-driven phase stability and charge transport dynamics.By summarizing the performance benchmarking results of lithium/sodium/potassi-um-ion battery components,we reveal how entropy-mediated structural tailoring enhances cycle stability and ionic conductivity.Notably,we pioneer the systematic association of high-entropy effects to electrochemical interfaces,demonstrating their unique potential in stabil-izing solid-electrolyte interphases and suppressing transition metal dissolution.Emerging opportunities in machine learning-driven com-position screening and sustainable manufacturing are discussed alongside critical challenges,including performance variability metrics and cost-benefit analysis for industrial implementation.This work provides both fundamental insights and practical guidelines for advan-cing HEMs toward next-generation battery technologies.
基金Project(2010ZCO51)supported by Natural Science Foundation of Yunnan ProvinceProject supported by Analysis and Testing Foundation(2009-041)Starting Research Fund(14118245)from Kunming University of Science and Technology
文摘As an improvement on the conventional two-layer electrode （active material layerlcurrent collector）, a novel sandwich-like three-layer electrode （conductive layerlactive material layertcurrent collector） for cathode material LiFePO4/C was introduced in order to improve its electrochemical performance. LiFePO4/C in the three-layer electrode exhibited superior rate capability in comparison with that in the two-layer electrode in accordance with charge-discharge examination. Cyclic voltammetry and electrochemical impedance spectroscopy indicated that Fe3＋/Fe2＋ redox couple for LiFePO4 in the three-layer electrode displayed faster kinetics, better reversibility and much lower charge transfer resistance than that in the two-layer electrode in electrochemical process. For three-layer electrode, the holes in the surface of active material layer were filled by smaller acetylene black grains, which formed electrical connections and provided more pathways to electron transport to/from LiFePO4/C particles exposed to the bulk electrolyte.
基金Funded by National Natural Science Foundation of China(No.52108188)State Key Laboratory of Silicate Materials for Architectures(Wuhan University of Technology)(No.SYSJJ2024-15)+3 种基金State Key Laboratory of Mountain Bridge and Tunnel Engineering,Chongqing Jiaotong University(No.SKLBT-2301)Opening Project of State Key Laboratory of Green Building Materials(No.2022GBM10)Open Research Fund of Key Laboratory of Engineering Materials of Ministry of Water Resources,China Institute of Water Resources and Hydropower Research(No.EMF202407)General Project of Science and Technology Plan of Beijing Municipal Commission of Education(No.KM202110005018)。
文摘This article investigated the factors and mechanisms that affected the workability and mechanical properties of cement paste incorporating nano-TiO_(2).The findings indicated that,for nano-TiO_(2)aqueous solution concentrations of 3%,6%,9%,and 12%,the optimal dispersion effect was achieved with an ultrasonic dispersion time of 20 minutes.Specifically,at a 6%nano-TiO_(2)content,both the workability and mechanical performance of the cement paste were enhanced.Furthermore,while nano-TiO_(2)did not alter the types of hydration products present in the cement paste,it did increase the amount of C-S-H gels.This enhancement was attributed to a higher number of nucleation sites for hydration products,which promoted hydration and reduced the porosity of the cement paste.
基金supported by the Shandong Natural Science Foundation Youth Project(No.ZR2023QE075)the Open Project Program of Shandong Marine Aerospace Equipment Technological Innovation Center(No.MAETIC202210)the Shandong Natural Science Foundation Project(No.ZR2022ME145)。
文摘The oscillating hydrofoil represents a promising technology for harvesting energy from tidal currents.While previous research has primarily focused on oscillating hydrofoils utilizing a fully activated control strategy,the industry predominantly employs a semi-activated control strategy in existing tidal current energy converters.It is essential to identify the differences in predicted energy-harvesting performance between these two controlling strategies through experimental modeling or numerical studies.Furthermore,the suitability of the fully activated control strategy in predicting the energy-harvesting capabilities of oscillating hydrofoils is evaluated.The 2D numerical models of hydrofoil based on fully activated and semi-activated control strategies have been developed and validated.The amplitudes of heaving and pitching movements for the fully activated hydrofoil are determined to match those of the semi-activated hydrofoil.The results show that the main difference between the two control strategies lies in the phase shift occurring between the pitching and heaving motions.This phase shift affects the lift force and its coordination with the heaving velocity,which in turn affects the power output.Notably,the maximum relative efficiency difference obtained between the fully activated and semi-activated control strategies can reach 191%.
基金supported by the National Natural Science Foundation of China(Nos.22408072 and 22208074)Hainan Province Science and Technology Special Fund(No.ZDYF2024GXJS300)Hainan Provincial Natural Science Foundation of China(No.222QN225)。
文摘Coating techniques are efficient routes to modify surface property of composite membranes for enhanced membrane separations.However,it remains challenge to deposit continuous inorganic layers on hollow fiber substrates.This study combines surface segregation with physical vapor deposition(PVD)to construct intensified TiO_(2)layers on polyether sulfone(PES)hollow fiber substrates.During membrane fabrication,polyethylene-polypropylene glycol(F127)is used as surface segregation agent in casting solution,which enables PES hollow fibers with abundant hydroxy groups,thus improving the compatibility between PES and vaporized TiO_(2).The obtained PES/F127@TiO_(2)membranes exhibit tight TiO_(2)layers with tunable thickness,high mechanical strength,narrowed pore size and enhanced hydrophilicity.Moreover,the optimized PES/F127@TiO_(2)membranes show competitive antifouling performances in water treatment,with a water permeability up to 97 L·m^(-2)·h^(-1)·bar^(-1)and bovine serum albumin(BSA)rejection of~99%.This work is expected to provide a material design idea to deposit functional layers on polymers for fortified performances.
基金funded by the Project of the Hubei Provincial Department of Science and Technology(Grant No.2022CFB957)the Project of Hubei Engineering University of Teaching Research(Grant No.JY2024032)+1 种基金Ministry of Education University-Industry Cooperation Collaborative Education Project(Grant No.220903584161245)College Students’Innovation and Entrepreneurship Training Program(Grant Nos.DC2024031,DC2024032).
文摘The behavior of single-phase flow and conjugate heat transfer in micro-channel heat sinks(MCHS)subjected to auniform heat flux is investigated by means of numerical simulations.Various geometrical configurations areexamined,particularly,the combinations of rectangular solid and perforated blocks,used to create a disturbancein the flow.The analysis focuses on several key aspects and related metrics,including the temperature distribution,the mean Fanning friction factor,the pressure drop,the Nusselt number,and the overall heat transfer coefficientacross a range of Reynolds numbers(80–870).It is shown that the introduction of such blocks significantlyenhances the heat transfer performances of the MCHS compared to the straight-through flow channel.Specifically,a case is found where the Nusselt number increases by 2.3 times relative to the reference case.The integrationof perforated blocks facilitates the generation of vorticity within the channel,promoting the mixing of coldand hot fluids.Notably,MCHS incorporating perforated rectangular blocks exhibit more pronounced heat transferbenefits at Reynolds numbers smaller than 400.
基金This work was supported by the National Natural Science Foundation of China （No.21373132, No.21502109, No.21603133）, the Education Department of Shmunxi Provincial Government Research Projects （No.16JK1142, No.16JK1134）, and the Scientific Research Foundation of Shaanxi University of Technology for Recruited Talents （No.SLGKYQD2-13, No.SLGKYQD2-10, No.SLGQD14-10）.
文摘Designing and fabricating high-performance photovoltaic devices have remained a major challenge in organic solar cell technologies. In this work, the photovoltaic performances of BTBPD-PC61BM system were theoretically investigated by means of density functional theory calculations coupled with the Marcus charge transfer model in order to seek novel photovoltaic systems. Moreover, the hole-transfer properties of BTBPD thin-film were also studied by an amorphous cell with 100 BTBPD molecules. Results revealed that the BTBPD- PC61BM system possessed a middle-sized open-circuit voltage of 0.70 V, large short-circuit current density of 16.874 mA/cm2, large fill factor of 0.846, and high power conversion effi- ciency of 10%. With the Marcus model, the charge-dissociation rate constant was predicted to be as fast as 3.079×10^13 s^-1 in the BTBPD-PC61BM interface, which was as 3-5 orders of magnitude large as the decay （radiative and non-radiative） rate constant （108-10^10 s^-1）, indicating very high charge-dissociation efficiency （-100%） in the BTBPD-PC61BM system. Furthermore, by the molecular dynamics simulation, the hole mobility for BTBPD thin-film was predicted to be as high as 3.970× 10^-3 cm^2V^-1s^-1, which can be attributed to its tight packing in solid state.
基金Projects (2008BAB32B14, 2008BAB31B03) supported by the National Key Technology R&D Program of China Project (51004027) supported by the National Natural Science Foundation of China
文摘The collecting performances of N-dodecylethylene-diamine （ND） to quartz and hematite were studied via single mineral flotation. Experimental results show that ND has stronger collecting ability to quartz than hematite. Different floatability of quartz and hematite was presented in the existence of depressant. Compared with lauryl amine, ND has stronger collecting performances to quartz. Satisfied separation result of artificially mixed sample was acquired with iron grade of concentrate of 59.92% and iron recovery of 88.85% when pulp pH value was 7.27 with 41.7 mg/L collector and 3.33 mg/L starch. Polar group properties calculation results indicated that ND has stronger collecting capability and better selectivity than lauryl amine. Measurement results of zeta-potentials and infrared spectrum showed that hydrogen bonding adsorption and electrostatic adsorption occur between the surface of ND and quartz.
基金Supported by National Key Technology R & D Program(2007BAD55B03)~~
文摘[Objective] The aim of this study was to investigate the correlation between blood protein polymorphism of red steppe and its performance.[Method]Two blood protein polymorphic loci were detected in transferring(Tf)and posttremsferr(Ptf)from thirteen red steppes and eighteen hybrid of limousin and red steppe by polyacrylamide gel electrophoresis.[Result]Tf and Ptf were controlled by three and two alleles respectively.[Conclusion]The variance analysis of blood protein polymorphic loci and its performance indicates that two protein loci have a positive or negative correlation with some traits of red steppe and the improved limousin cattle population.
基金Projects(51161015,51371094) supported by the National Natural Science Foundation of China
文摘In order to investigate the influences of the stoichiometric ratio of La/Mg （increasing La and decreasing Mg on the same mole ratio） on the structure and electrochemical performances of the La-Mg-Ni-based A2B7-type electrode alloy, the as-cast and the annealed ternary Lao.8＋xMgo.2_xNi3.5 （x=0-0.05） electrode alloys were prepared. The characterization of electrode alloys by X-ray diffraction （XRD） and scanning electron microscopy （SEM） shows that all the as-cast and the annealed alloys hold two major phases of （La,Mg）2Ni7 and LaNi5 as well as a residual phase of LaNi3. Moreover, the increase of La/Mg ratio brings on a decline of （La,Mg）2Ni7 phase and a rise of LaNi5 and LaNi3 phases. The variation of La/Mg ratio gives rise to an evident change of the electrochemical performances of the alloys. The discharge capacities of the as-cast and the annealed alloys evidently decrease with growing the La/Mg ratio, while the cycle stabilities of the alloys visibly augment under the same condition. Furthermore, the high rate discharge ability （HRD）, the electrochemical impedance spectrum （EIS）, the Tafel polarization curves, and the potential step measurements all indicate that the electrochemical kinetic properties of the alloy electrodes increase with the La/Mg ratio rising.
基金supported by the National Natural Science Foundation of China (30871795)the Earmarked Fund for Modern Agro-Industry Technology Research System, China (nycytx-45-13)
文摘This study was carried out to unravel the mechanism of reductions in production performances in high stocking density geese flocks during summer months in ＂geese-fish＂ production system. Experiment 1 observed the water bacterial growth, lipopolysaccharde concentrations in water and geese blood, and geese reproductive performances from summer to winter, in two flocks with varying on water stocking densities. Results showed that counts of total bacteria, Escherichia coli and Salmonella in water, as well as water and geese plasma LPS concentrations, exhibited a tendency decreasing from the highest levels in summer, to intermediate levels in autumn, and to the lowest values in winter. Such seasonal decreases in bacteria and LPS concentrations were associated with similar seasonal decreases in embryo mortality during incubation. In addition, embryos dead or showing development retardation by day 25 of incubation contained copious LPS in allantoic fluid, in contrast to the negligible amount in normal developing embryos. Raising on water stocking density elevated bacteria counts, LPS concentrations in water and geese plasma, and decreased egg fertility but increased embryo mortality during incubation. In experiment 2, exogenous LPS treatment to the geese depressed egg laying, reduced egg hatchability, caused sickness behavior in the goslings hatched. In experiment 3, exogenous LPS directly administered to day 8 and 18 embryos during incubation dose dependently increased mortality and decreased hatchability, and caused sickness behavior in the goslings hatched. It is concluded that the raising on water geese stocking density stimulates pathogenic bacteria growth in water, which via LPS contamination impaires embryo development in incubation and therefore reduces geese reproductive performance and gosling quality during the hot summer months.
文摘By using Bayesian and multiple Bayesian method, the failure probability, reliability and mean time to failure(MTTF) of series system with cold standby units are estimated. At last, we compare the two estimators by means of Monte_Carlo simulation.
基金Project supported by National Natural Science Foundation of China(51001043,50971112)Program for New Century Excellent Talents in University(NCET-11-0943)+2 种基金China Postdoctoral Science Special Foundation(201104390)Foundation for University Key Teacher in the University of Henan Province(2011GGJS-052)Program for Innovative Research Team(in Science and Technology)in the University of Henan Province(2012IRTSTHN007)
文摘Hydrogen storage properties of 2LiNH2-MgH2 system were improved by adding lanthanum hydride （LaH3）, and the role of LaH3 in hydrogen sorption process of Li-Mg-N-H system was investigated. Temperature programmed sorption results showed that the addition of lanthanum hydride reduced the dehydriding/hydriding onset temperature of 2LiNH2-MgH2 system by at least 15 K. Moreover, A 0.053 wt.%/min average rate was determined for the hydrogen desorption of 2LiNH2-MgH2-0.05LaH3 composite, while it was only 0.035 wt.%/min for 2LiNH2-MgH2 system. Hydrogen absorption capacity increased from 1.62 wt.% to 2.12 wt.% within 200 min by adding LaH3 into 2LiNH2-MgH2 system at 383 K. In the dehydrogenation of 2LiNH2-MgH2-0.05LaH3 composite, LaH2 transferred to LaN phase, which reversed to LaH2 in the following hydrogen adsorption process. The reversible reaction of LaH2 ef- fectively promoted the hydrogen sorption of Li-Mg-N-H system. Moreover, the homogenous distribution of fine La hydride was fa- vorable to improving effect of lanthanum hydride.
基金supported by the Base of the Key Technologies R & D Program of Anhui Province (1704c0402195)the Fundamental Research Funds for the Central Universities (PA2019GDPK0043,JZ2019HGBZ0142,JZ2019YYPY0291)。
文摘Al coated NdFeB magnets obtained by vacuum evaporation technique were densified by high energy ball milling method.The surface morphology,metal composition and micro structure of the coatings were characterized by scanning electron microscopy,X-ray diffraction and X-ray photoelectron spectroscopy,respectively.The anticorrosive properties were investigated by potentiodynamic polarization curves and neutral salt spray test.The pores in the Al coatings of columnar crystals(Al) induced by the evaporation technique,were apparently filled in the following ball milling process,leading to the densification of Al coatings and the evident improvement of the anticorrosive performances.When treated with ball milling for 30 min,the sample achieves the best anticorrosive performances with the self-corrosion potential of-0.87 V,self-corrosion current density of 1.65 μA/cm^(2) and the neutral salt spray(NSS) time of 144 h(red rust).The improvement of the anticorro sive performances of vacuum evaporated Al coating mainly lies in the densification effect of the coating,which depends on different loading conditions of ball milling process.
基金supported by the Shanghai Science and Tech-nology Committee(No.22511102400)Prof.Zhang would like to appreciate the financial support from the Fundamental Research Funds for the Central Universities(No.2232020G-12)+1 种基金the Fund of National Engineering Research Center for Commercial Aircraft Manufacturing(No.COMAC-SFGS-2022-2376)the Textile Vi-sion Basic Research Program(No.J202105).
文摘In this study, two-dimensional MXene (Ti3 C2 Tx ) was employed to modify the interface of carbon fiber-reinforced polyetherketoneketone (CF/PEKK) composites, in order to simultaneously improve the electromagnetic interference (EMI) shielding performances and mechanical properties. The obtained CF/PEKK composites possessed outstanding EMI and mechanical performances, as anticipated. Specifically, the CF/PEKK composites modified with MXene at 1 mg mL–1 exhibited an excellent EMI shielding effectiveness of 65.2 dB in the X-band, a 103.1% enhancement compared with the unmodified CF/PEKK composites. The attractive EMI shielding performances of CF/PEKK composites originated from enhanced ohmic losses and multiple reflections of electromagnetic waves with the help of the MXene and CF layers. In addition, CF/PEKK composites achieved the best mechanical properties by optimizing the dispersion concentration of MXene to 0.1 mg mL–1 . The flexural strength, flexural modulus, and interlaminar shear strength of CF/PEKK composites reached 1127 MPa, 81 GPa, and 89 MPa, which were 28.5%, 9.5%, and 29.7% higher than that of the unmodified CF/PEKK composites, respectively. Such improvement in mechanical properties could be ascribed to the comprehensive effect of mechanical interlocking, hydrogen bonds, and Van der Waals forces between the introduced MXene and CF, PEKK, respectively.
