Space metallurgy is an interdisciplinary field that combines planetary space science and metallurgical engineering.It involves systematic and theoretical engineering technology for utilizing planetary resources in sit...Space metallurgy is an interdisciplinary field that combines planetary space science and metallurgical engineering.It involves systematic and theoretical engineering technology for utilizing planetary resources in situ.However,space metallurgy on the Moon is challenging because the lunar surface has experienced space weathering due to the lack of atmosphere and magnetic field,making the mi-crostructure of lunar soil differ from that of minerals on the Earth.In this study,scanning electron microscopy and transmission electron microscopy analyses were performed on Chang’e-5 powder lunar soil samples.The microstructural characteristics of the lunar soil may drastically change its metallurgical performance.The main special structure of lunar soil minerals include the nanophase iron formed by the impact of micrometeorites,the amorphous layer caused by solar wind injection,and radiation tracks modified by high-energy particle rays inside mineral crystals.The nanophase iron presents a wide distribution,which may have a great impact on the electromagnetic prop-erties of lunar soil.Hydrogen ions injected by solar wind may promote the hydrogen reduction process.The widely distributed amorph-ous layer and impact glass can promote the melting and diffusion process of lunar soil.Therefore,although high-energy events on the lun-ar surface transform the lunar soil,they also increase the chemical activity of the lunar soil.This is a property that earth samples and tradi-tional simulated lunar soil lack.The application of space metallurgy requires comprehensive consideration of the unique physical and chemical properties of lunar soil.展开更多
Adopting a nano-and micro-structuring approach to fully unleashing the genuine potential of electrode active material benefits in-depth understandings and research progress toward higher energy density electrochemical...Adopting a nano-and micro-structuring approach to fully unleashing the genuine potential of electrode active material benefits in-depth understandings and research progress toward higher energy density electrochemical energy stor-age devices at all technology readiness levels.Due to various challenging issues,especially limited stability,nano-and micro-structured(NMS)electrodes undergo fast electrochemical performance degradation.The emerging NMS scaffold design is a pivotal aspect of many electrodes as it endows them with both robustness and electrochemical performance enhancement,even though it only occupies comple-mentary and facilitating components for the main mechanism.However,extensive efforts are urgently needed toward optimizing the stereoscopic geometrical design of NMS scaffolds to minimize the volume ratio and maximize their functionality to fulfill the ever-increasing dependency and desire for energy power source supplies.This review will aim at highlighting these NMS scaffold design strategies,summariz-ing their corresponding strengths and challenges,and thereby outlining the potential solutions to resolve these challenges,design principles,and key perspectives for future research in this field.Therefore,this review will be one of the earliest reviews from this viewpoint.展开更多
Operating conditions strongly affect the yield and quality of polysilicon in a polysilicon fluidized bed.In this study,a new model of polysilicon fluidized bed was established using the Euler-Euler model coupled with ...Operating conditions strongly affect the yield and quality of polysilicon in a polysilicon fluidized bed.In this study,a new model of polysilicon fluidized bed was established using the Euler-Euler model coupled with population balance model(PBM),which was combined with fluid flow,heat,and mass transfer models,while considering the scavenging effect of silicon fines.The effects of different operating conditions on the deposition and formation rates of silicon fines were investigated.Results show that the model can correctly describe the particle growth process in the fluidized bed of polysilicon.The silicon fines and the interphase velocity difference show"N"-and"M"-shaped distributions along the axial direction,respectively.The particle temperature and concentration near the wall are higher than those in the central region.The decomposition of silane in the bottom region of the bed is dominated by het-erogeneous deposition.The scavenging of silicon fines occurs in the dilute-phase region.The effects of operating conditions,i.e.inlet gas temperature,silane composition,and gas velocity,on the reactor performance were also explored comprehensively.Increasing the inlet gas composition and velocity enhances the formation rates of solid silicon and fines.Increasing the inlet gas temperature promotes the growth of solid silicon and inhibits the formation of silicon fines.High fluidization ratio,low inlet silane concentration,and high inlet gas temperature enhance the selectivity of silicon growth.展开更多
Hydrogen energy has been recognized as“Ultimate Power Source”in the 21st century.It is a boon in these days of energy crunches and concerns about climate change because of the characterized advantages,such as high e...Hydrogen energy has been recognized as“Ultimate Power Source”in the 21st century.It is a boon in these days of energy crunches and concerns about climate change because of the characterized advantages,such as high energy density,large calorific value,abundant resource,zero pollution,zero carbon emission,storable and renewable.State-of-the-art perspectives on tuning the stable thermodynamics and sluggish kinetics of dehydrogenation and re-hydrogenation of LiBH4,which has been regarded as a promising hydrogen storage alternative for onboard energy carrier applications have been discussed.Five major technological approaches are involved,including nanoengineering,catalyst modification,ions substitution,reactant destabilization and a novel process termed as high-energy ball milling with in-situ aerosol spraying(BMAS).It is worth noting that BMAS has the potential to help overcome the kinetic barriers for thermodynamically favorable systems like LiBH4 t MgH2 mixture and provide thermodynamic driving force to enhance hydrogen release at a lower temperature.展开更多
Three-dimensional graphene materials have been studied as typical supercapacitors electrode materials by virtue of their ultrahigh specific surface area and good ion transport capacity.However,improvement of the poor ...Three-dimensional graphene materials have been studied as typical supercapacitors electrode materials by virtue of their ultrahigh specific surface area and good ion transport capacity.However,improvement of the poor volumetric electrochemical performance of these graphene materials has been required although they have high gravimetric energy density.In this work,nanocellulose/nitrogen and fluorine co-doped graphene composite hydrogels(NC-NFGHs)were prepared through a convenient hydrothermal approach utilizing ammonium fluoride as the heteroatom source.Nanocellulose(NC)and high concentration of graphene oxide(GO)were utilized to adjust the structure of NC-NFGHs and increase their packing density.Subsequently,the aqueous symmetric supercapacitor based on NC-NFGH-80 exhibits remarkable gravimetric(286.6 F·g^(-1))and volumetric(421.3 F·cm^(-3))specific capacitance at 0.3 A·g^(-1),good rate performance,and remarkable cycle stability up to 10,000 cycles.Besides,the all-solid-state flexible symmetric supercapacitors(ASSC)fabricated by NC-NFGH-80 also delivered a large specific capacitance of 117.1 F·g^(-1)at 0.3 A·g^(-1)and long service life over 10,000 cycles at 10 A·g^(-1).This compact porous structure and heteroatom co-doped graphene material supply a favorable strategy for high-performance supercapacitors.展开更多
The lunar mare potassium(K)-,rare-earth elements(REEs)-and phosphorous(P)-rich(KREEP-rich) region is a unique late-stage product of magma crystallization,in which ilmenite and incompatible elements have high grades,th...The lunar mare potassium(K)-,rare-earth elements(REEs)-and phosphorous(P)-rich(KREEP-rich) region is a unique late-stage product of magma crystallization,in which ilmenite and incompatible elements have high grades,thus forming a giant natural reservoir.The extraction and purification of the high-value metal resources in the KREEP-rich region not only meet the construction needs of the lunar base but also solve the problem of resource scarcity on Earth.In this study,photovoltaic elemental silicon(Si) was used as a collector to extract ilmenite resources,REEs,and nuclear energy elements from basalt in the lunar mare KREEP-rich region at 1873 K.Based on experimentation,the metals titanium(Ti)and iron(Fe) in the lunar mare ilmenite are found to be enriched and solidified in the form of Si-based alloys.The contents of valuable incompatible elements in the KREEP-rich area are also found to be enriched and contained in the incompatible trace elements(ITEs) phase of the alloy.Among them,REEs(e.g.,cerium(Ce) and thulium(Tm)) and nuclear elements(e.g.,thorium(Th) and uranium(U)) are found to account for 82.61 wt% of the ITEs phase.This process provides a simple and feasible scheme for the insitu resource utilization(ISRU) of the lunar surface and is suitable for the extraction and enrichment of lunar metal resources.展开更多
The structure of the gas distributor is closely related to the production efficiency of organosilicon monomers.To improve the production efficiency of organosilicon monomers,this study uses Eulerian-Eulerian two fluid...The structure of the gas distributor is closely related to the production efficiency of organosilicon monomers.To improve the production efficiency of organosilicon monomers,this study uses Eulerian-Eulerian two fluid model and proposes a design formula for the gas distributor to optimize the gas distributor.It is proposed that the pressure drop of the gas distributor,the velocity nonuniformity coefficient,the relative standard deviation of the solid holdup,and the solid particle dispersion coefficient are used to evaluate the performance of the gas distributor.The results show that the performance of the gas distributor is significantly improved when the opening ratioΦ=0.53%is optimized toΦ=0.18%,in which the relative standard deviation of the solid holdup is reduced by 22%,and the solid particle dispersion coefficient is reduced by 40%.On this basis,this article studies the influence of different arrangements of vent holes on gas-solid fluidization characteristics.The results show that the circular arrangement of vent holes is helpful to the mixing of gas and solid.展开更多
Si-based photovoltaic solar power has been rapidly developed as a renewable and green energy source.The widespread use of Sibased solar cells requires large amounts of solar-grade Si(SoG-Si)to manufacture Si wafers.Ch...Si-based photovoltaic solar power has been rapidly developed as a renewable and green energy source.The widespread use of Sibased solar cells requires large amounts of solar-grade Si(SoG-Si)to manufacture Si wafers.Chemical routes,mainly the modified Siemens process,have dominated the preparation of polycrystalline SoG-Si;however,traditional chemical techniques employ a series of complex chemical reactions involving various corrosive and hazardous reagents.In addition,large amounts of complex waste solar cells and Si kerf slurry waste gradually accumulate and are difficult to recycle using these approaches.New methods are required to meet the demand for SoGSi preparation and Si waste recycling.The metallurgical route shows promise but is hindered by the problem of eliminating B and P from metallurgical-grade Si(MG-Si).Various pyrometallurgical treatments have been proposed to enhance the removal of B and P from MG-Si.This article reviews Si refining with slag treatment,chlorination,vacuum evaporation,and solvent refining,and summarizes and discusses the basic principles and recent representative studies of the four methods.Among these,solvent refining is the most promising and environmentally friendly approach for obtaining low-cost SoG-Si and is a popular research topic.Finally,a simple and green approach,i.e.,a combination of solvent refining,slag treatment,or vacuum directional solidification,is proposed for low-cost SoG-Si preparation using MG-Si or Si wastes as raw materials.展开更多
In this study, graphene sheets are prepared under a hydrogen atmosphere without a catalyst, and the growth mechanism of graphene by direct current arc discharge is investigated experimentally and numerically. The size...In this study, graphene sheets are prepared under a hydrogen atmosphere without a catalyst, and the growth mechanism of graphene by direct current arc discharge is investigated experimentally and numerically. The size and layer numbers of graphene sheets increase with the arc current.Distributions of temperature, velocity, and mass fraction of carbon are obtained through numerical simulations. A high current corresponds to a high saturation temperature, evaporation rate, and mass density of carbon clusters. When the carbon vapor is saturated, the saturation temperatures are 3274.9, 3313.9, and 3363.6 K, and the mass densities are 6.4×1022,8.42×1022, and 1.23×1023 m-3 under currents of 150, 200, and 250 A, respectively. A hydrogen-induced marginal growth model is used to explain the growth mechanism. Under a high current, the condensation coefficient and van der Waals force increase owing to the higher saturation temperature and mass density of carbon clusters, which is consistent with experimental results.展开更多
The mitochondrial genome(mitogenome)of hybrid grouper Epinephelus moara(♀)×Epinephelus tukula(♂),a new hybrid progeny,can provide valuable information for analyzing phylogeny and molecular evolution.In this stu...The mitochondrial genome(mitogenome)of hybrid grouper Epinephelus moara(♀)×Epinephelus tukula(♂),a new hybrid progeny,can provide valuable information for analyzing phylogeny and molecular evolution.In this study,the mitogenome was analyzed using PCR amplification and sequenced,then the phylogenetic relationship of E.moara(♀)×E.tukula(♂)and 35 other species were constructed using Maximum Likelihood and NeighborJoining methods with the nucleotide sequences of 13 conserved protein-coding genes(PCGs).The complete mitogenome of E.moara(♀)×E.tukula(♂)was 16695 bp in length,which contained 13 PCGs,2 rRNA genes,22 tRNA genes,a replication origin and a control region.The composition and order of these genes were consistent with most other vertebrates.Of the 13 PCGs,12 PCGs were encoded on the heavy strand,and ND6 was encoded on the light strand.The mitogenome of the E.moara(♀)×E.tukula(♂)had a higher AT nucleotide content,a positive AT-skew and a negative GC-skew.All protein initiation codons were ATG,except for COX and ND4(GTG),ATP6(CTG),and ND3(ATA).ND2,COXII,ND3,ND4 and Cytb had T as the terminating codon,COXIII’s termination codon was TA,and the remaining PCGs of that were TAA.All tRNA genes,except for the lacking DHU-arm of tRNASer(AGN),were predicted to form a typical cloverleaf secondary structure.In addition,sequence similarity analysis(99%identity)and phylogenetic analysis(100%bootstrap value)indicated that the mitochondrial genome was maternally inherited.This study provides mitogenome data for studying genetic,phylogenetic relationships and breeding of grouper.展开更多
‘Jinxiu' is a processing apricot(Armeniaca vulgaris L.) cultivar derived from the cross of ‘Chuanzhihong'בJintaiyang'.The fruit is oval-shaped with the ground color of orange and 1/4-1/2 sheet red...‘Jinxiu' is a processing apricot(Armeniaca vulgaris L.) cultivar derived from the cross of ‘Chuanzhihong'בJintaiyang'.The fruit is oval-shaped with the ground color of orange and 1/4-1/2 sheet red in the surface. The average fruit weight is65.5 g, and the maximum value is 106 g. The flesh is orange, fine with very less fiber, toughness, less juice and freestone, and tastes sour and sweet. The soluble solid content is 12.5%. The edible rate is 95.8%. The fruit skin hardness is 12.9 kg/cm2 and storable. The preserved apricots have orange color and are tasty. The preserved yield is 40%. The fruit development period is 72 d. The fruit has high yield, and the fruit yield in full fruit period can reach 37 000 kg/hm2. ‘Jinxiu' was examined and approved by Hebei Examination and Approval Committee of Forest Tree Variety in 2013.展开更多
In this study,Cu/Ni-La_(0.7)Sr_(0.3)Cr_(0.5)Mn_(0.5)O_(3-δ)(LSCM) catalysts were synthesized via the citric acid-nitrate process(CNP) and chemical co-precipitation. The catalytic performance of Cu/Ni-LSCM catalysts o...In this study,Cu/Ni-La_(0.7)Sr_(0.3)Cr_(0.5)Mn_(0.5)O_(3-δ)(LSCM) catalysts were synthesized via the citric acid-nitrate process(CNP) and chemical co-precipitation. The catalytic performance of Cu/Ni-LSCM catalysts on dry methane reforming was evaluated in a fixed-bed reactor at 550/650 ℃ and atmosphere pressure. Cu/Ni loading was investigated as an influencing factor, which led to 5 cases of samples according to the different Cu/Ni mass ratios. The catalysts were characterized by X-ray diffraction(XRD), field emissionscanning electron microscope(FE-SEM), Brunauer-Emmett-Teller(BET) measurement, X-ray photoelectron spectroscopy(XPS), hydrogen-based temperature-programmed reduction(H_2-TPR) and thermos gravimetric analyzer(TGA). The results show that the methane conversion increases, the resistance against metal sintering increases and the carbon deposition drops after the copper is introduced. This optimum performance can be obtained under Case 3(Cu:Ni:LSCM = 1:3:6 in mass ratio).展开更多
In this study,impurity-free porous graphene(PG) with intrinsic pore structure was synthesized through a facile acid-alkali etching-assisted sonication approach.The pore structure appears on the surface of graphene she...In this study,impurity-free porous graphene(PG) with intrinsic pore structure was synthesized through a facile acid-alkali etching-assisted sonication approach.The pore structure appears on the surface of graphene sheets due to intrinsic defects of graphene.The PG possessed an extremely high specific surface area of 2184 m^2/g,the size of^5 μm and layer numbers of 3-8.Additionally,PG contained micropores and mesopores simultaneously,with an average pore diameter of approximately 3 nm.The effects of acid,alkali,and ultrasound treatment on PG preparation were elucidated by transmission electron microscopy and fourier transform infrared spectroscopy.First,in an acidic solution,oxygen-containing functional groups(hydroxyls,carboxyl,and epoxides) were formed due to the hydrolysis of sulfate and continuous transformations of these functional groups on graphene oxide.Second,under the synergistic effects of alkali and ultrasound treatment,PG was obtained due to the loss of carboxyl and epoxide groups.A new route for preparing PG was provided by the proposed method.展开更多
In recent years,a novel PEDOT:PSS/n-Si planar heterojunction solar cell has been extensively studied in the photovoltaic field.Different V_(2)O_(5)-IPA concentrations mixed in PEDOT:PSS samples as hole transport layer...In recent years,a novel PEDOT:PSS/n-Si planar heterojunction solar cell has been extensively studied in the photovoltaic field.Different V_(2)O_(5)-IPA concentrations mixed in PEDOT:PSS samples as hole transport layer were prepared by means of spin coating technique and mechanical mixing of organic and inorganic materials.V_(2)O_(5)was studied for its effects on the surface morphology,chemical composition,and optical transmittance of PEDOT:PSS films.The findings of the study show that the addition of V_(2)O_(5)particles changes the surface morphology of PEDOT:PSS films and promotes its superior ohmic contact with the Si interface.Furthermore,PEDOT:PSS incorporated with V_(2)O_(5)particles that have outstanding optical and semiconductor properties reduces the rate of carrier recombination at the device interface and blocks electron transport to the anode in the fabricated Si-based solar cells.When compared to conventional PEDOT:PSS/Si planar heterojunction solar cells,the fill factor,photoelectric conversion efficiency,open-circuit voltage,and short-circuit current density of the devices prepared in this study can be significantly improved,reaching up to 70.98%,15.17%,652 mV and 32.8 mA/cm^(2),respectively.This research provides a promising and effective method for improving the photoelectric conversion performance of PEDOT:PSS/Si heterojunction solar cells,which enables the application of V_(2)O_(5)in Si solar cells.展开更多
基金CNSA for providing access to the lunar sample CE5C0200YJFM00302funding support from the Strategic Priority Research Program of the Chinese Academy of Sciences (No. XDB 41000000)+5 种基金the National Natural Science Foundation of China (Nos. 42273042 and 41931077)the Youth Innovation Promotion Association Chinese Academy of Sciences (No. 2020395)Key Research Program of Frontier Sciences, Chinese Academy of Sciences (Nos. ZDBS-SSW-JSC00710 and QYZDY-SSW-DQC028)the Young and Middleaged Academic Technology Leader Reserve Talent Project of Yunnan Province (No. 2018HB009)the Science Fund for Outstanding Youth of Yunnan Province (No. 202101 AV070007)the "From 0 to 1" Original Exploration Cultivation Project, Institute of Geochemistry, Chinese Academy of Sciences (No. DHSZZ2023-3)
文摘Space metallurgy is an interdisciplinary field that combines planetary space science and metallurgical engineering.It involves systematic and theoretical engineering technology for utilizing planetary resources in situ.However,space metallurgy on the Moon is challenging because the lunar surface has experienced space weathering due to the lack of atmosphere and magnetic field,making the mi-crostructure of lunar soil differ from that of minerals on the Earth.In this study,scanning electron microscopy and transmission electron microscopy analyses were performed on Chang’e-5 powder lunar soil samples.The microstructural characteristics of the lunar soil may drastically change its metallurgical performance.The main special structure of lunar soil minerals include the nanophase iron formed by the impact of micrometeorites,the amorphous layer caused by solar wind injection,and radiation tracks modified by high-energy particle rays inside mineral crystals.The nanophase iron presents a wide distribution,which may have a great impact on the electromagnetic prop-erties of lunar soil.Hydrogen ions injected by solar wind may promote the hydrogen reduction process.The widely distributed amorph-ous layer and impact glass can promote the melting and diffusion process of lunar soil.Therefore,although high-energy events on the lun-ar surface transform the lunar soil,they also increase the chemical activity of the lunar soil.This is a property that earth samples and tradi-tional simulated lunar soil lack.The application of space metallurgy requires comprehensive consideration of the unique physical and chemical properties of lunar soil.
基金The authors acknowledge support from the German Research Foundation(DFG:LE 2249/5-1)the Sino-German Center for Research Promotion(GZ1579)+1 种基金Yunnan Fundamental Research Projects(202201AW070014)Jiajia Qiu and Yu Duan appreciate support from the China Scholarship Council(No.201908530218&202206990027).
文摘Adopting a nano-and micro-structuring approach to fully unleashing the genuine potential of electrode active material benefits in-depth understandings and research progress toward higher energy density electrochemical energy stor-age devices at all technology readiness levels.Due to various challenging issues,especially limited stability,nano-and micro-structured(NMS)electrodes undergo fast electrochemical performance degradation.The emerging NMS scaffold design is a pivotal aspect of many electrodes as it endows them with both robustness and electrochemical performance enhancement,even though it only occupies comple-mentary and facilitating components for the main mechanism.However,extensive efforts are urgently needed toward optimizing the stereoscopic geometrical design of NMS scaffolds to minimize the volume ratio and maximize their functionality to fulfill the ever-increasing dependency and desire for energy power source supplies.This review will aim at highlighting these NMS scaffold design strategies,summariz-ing their corresponding strengths and challenges,and thereby outlining the potential solutions to resolve these challenges,design principles,and key perspectives for future research in this field.Therefore,this review will be one of the earliest reviews from this viewpoint.
基金support by the Science and Technology Planning Project of the Science and Technology Department of Yunnan Province (grant No.202002AB080002 and 202202AB080014).
文摘Operating conditions strongly affect the yield and quality of polysilicon in a polysilicon fluidized bed.In this study,a new model of polysilicon fluidized bed was established using the Euler-Euler model coupled with population balance model(PBM),which was combined with fluid flow,heat,and mass transfer models,while considering the scavenging effect of silicon fines.The effects of different operating conditions on the deposition and formation rates of silicon fines were investigated.Results show that the model can correctly describe the particle growth process in the fluidized bed of polysilicon.The silicon fines and the interphase velocity difference show"N"-and"M"-shaped distributions along the axial direction,respectively.The particle temperature and concentration near the wall are higher than those in the central region.The decomposition of silane in the bottom region of the bed is dominated by het-erogeneous deposition.The scavenging of silicon fines occurs in the dilute-phase region.The effects of operating conditions,i.e.inlet gas temperature,silane composition,and gas velocity,on the reactor performance were also explored comprehensively.Increasing the inlet gas composition and velocity enhances the formation rates of solid silicon and fines.Increasing the inlet gas temperature promotes the growth of solid silicon and inhibits the formation of silicon fines.High fluidization ratio,low inlet silane concentration,and high inlet gas temperature enhance the selectivity of silicon growth.
基金the U.S.National Science Foundation(NSF)with the Award No.CMMI-1261782.
文摘Hydrogen energy has been recognized as“Ultimate Power Source”in the 21st century.It is a boon in these days of energy crunches and concerns about climate change because of the characterized advantages,such as high energy density,large calorific value,abundant resource,zero pollution,zero carbon emission,storable and renewable.State-of-the-art perspectives on tuning the stable thermodynamics and sluggish kinetics of dehydrogenation and re-hydrogenation of LiBH4,which has been regarded as a promising hydrogen storage alternative for onboard energy carrier applications have been discussed.Five major technological approaches are involved,including nanoengineering,catalyst modification,ions substitution,reactant destabilization and a novel process termed as high-energy ball milling with in-situ aerosol spraying(BMAS).It is worth noting that BMAS has the potential to help overcome the kinetic barriers for thermodynamically favorable systems like LiBH4 t MgH2 mixture and provide thermodynamic driving force to enhance hydrogen release at a lower temperature.
基金The authors gratefully acknowledge the support from the National Natural Science Foundation of China(No.52072191)Heilongjiang Provincial Natural Science Foundation of China(No.LH2020E126)the Fundamental Research Fund of Heilongjiang Provincial University(No.135509204).
文摘Three-dimensional graphene materials have been studied as typical supercapacitors electrode materials by virtue of their ultrahigh specific surface area and good ion transport capacity.However,improvement of the poor volumetric electrochemical performance of these graphene materials has been required although they have high gravimetric energy density.In this work,nanocellulose/nitrogen and fluorine co-doped graphene composite hydrogels(NC-NFGHs)were prepared through a convenient hydrothermal approach utilizing ammonium fluoride as the heteroatom source.Nanocellulose(NC)and high concentration of graphene oxide(GO)were utilized to adjust the structure of NC-NFGHs and increase their packing density.Subsequently,the aqueous symmetric supercapacitor based on NC-NFGH-80 exhibits remarkable gravimetric(286.6 F·g^(-1))and volumetric(421.3 F·cm^(-3))specific capacitance at 0.3 A·g^(-1),good rate performance,and remarkable cycle stability up to 10,000 cycles.Besides,the all-solid-state flexible symmetric supercapacitors(ASSC)fabricated by NC-NFGH-80 also delivered a large specific capacitance of 117.1 F·g^(-1)at 0.3 A·g^(-1)and long service life over 10,000 cycles at 10 A·g^(-1).This compact porous structure and heteroatom co-doped graphene material supply a favorable strategy for high-performance supercapacitors.
基金supported by the Yunnan Outstanding Youth Science Foundation (202101AV070007)the Reserve Talents of Young and Middle-aged Academic and Technical Leaders in Yunnan Province (2018HB009)Strategic Priority Research Program of the Chinese Academy of Sciences (XDB 41000000)。
文摘The lunar mare potassium(K)-,rare-earth elements(REEs)-and phosphorous(P)-rich(KREEP-rich) region is a unique late-stage product of magma crystallization,in which ilmenite and incompatible elements have high grades,thus forming a giant natural reservoir.The extraction and purification of the high-value metal resources in the KREEP-rich region not only meet the construction needs of the lunar base but also solve the problem of resource scarcity on Earth.In this study,photovoltaic elemental silicon(Si) was used as a collector to extract ilmenite resources,REEs,and nuclear energy elements from basalt in the lunar mare KREEP-rich region at 1873 K.Based on experimentation,the metals titanium(Ti)and iron(Fe) in the lunar mare ilmenite are found to be enriched and solidified in the form of Si-based alloys.The contents of valuable incompatible elements in the KREEP-rich area are also found to be enriched and contained in the incompatible trace elements(ITEs) phase of the alloy.Among them,REEs(e.g.,cerium(Ce) and thulium(Tm)) and nuclear elements(e.g.,thorium(Th) and uranium(U)) are found to account for 82.61 wt% of the ITEs phase.This process provides a simple and feasible scheme for the insitu resource utilization(ISRU) of the lunar surface and is suitable for the extraction and enrichment of lunar metal resources.
基金The authors are grateful to the financial support by the Science and Technology Planning Project of the Science and Technology Department of Yunnan Province(grant No.202002AB080002).
文摘The structure of the gas distributor is closely related to the production efficiency of organosilicon monomers.To improve the production efficiency of organosilicon monomers,this study uses Eulerian-Eulerian two fluid model and proposes a design formula for the gas distributor to optimize the gas distributor.It is proposed that the pressure drop of the gas distributor,the velocity nonuniformity coefficient,the relative standard deviation of the solid holdup,and the solid particle dispersion coefficient are used to evaluate the performance of the gas distributor.The results show that the performance of the gas distributor is significantly improved when the opening ratioΦ=0.53%is optimized toΦ=0.18%,in which the relative standard deviation of the solid holdup is reduced by 22%,and the solid particle dispersion coefficient is reduced by 40%.On this basis,this article studies the influence of different arrangements of vent holes on gas-solid fluidization characteristics.The results show that the circular arrangement of vent holes is helpful to the mixing of gas and solid.
文摘Si-based photovoltaic solar power has been rapidly developed as a renewable and green energy source.The widespread use of Sibased solar cells requires large amounts of solar-grade Si(SoG-Si)to manufacture Si wafers.Chemical routes,mainly the modified Siemens process,have dominated the preparation of polycrystalline SoG-Si;however,traditional chemical techniques employ a series of complex chemical reactions involving various corrosive and hazardous reagents.In addition,large amounts of complex waste solar cells and Si kerf slurry waste gradually accumulate and are difficult to recycle using these approaches.New methods are required to meet the demand for SoGSi preparation and Si waste recycling.The metallurgical route shows promise but is hindered by the problem of eliminating B and P from metallurgical-grade Si(MG-Si).Various pyrometallurgical treatments have been proposed to enhance the removal of B and P from MG-Si.This article reviews Si refining with slag treatment,chlorination,vacuum evaporation,and solvent refining,and summarizes and discusses the basic principles and recent representative studies of the four methods.Among these,solvent refining is the most promising and environmentally friendly approach for obtaining low-cost SoG-Si and is a popular research topic.Finally,a simple and green approach,i.e.,a combination of solvent refining,slag treatment,or vacuum directional solidification,is proposed for low-cost SoG-Si preparation using MG-Si or Si wastes as raw materials.
基金supported by National Natural Science Foundation of China (No. 11765010)the National Key Research and Development Program of China (No. 2019YFC1907900)+2 种基金the Applied Basic Research Programs of Yunnan Provincial Science and Technology Department (No. 202001AW070004)the Freely Exploring Fund for Academicians in Yunnan Province (No. 2018HA006)the Key Laboratory of Resource Chemistry, Ministry of Education (No. KLRCME2001)
文摘In this study, graphene sheets are prepared under a hydrogen atmosphere without a catalyst, and the growth mechanism of graphene by direct current arc discharge is investigated experimentally and numerically. The size and layer numbers of graphene sheets increase with the arc current.Distributions of temperature, velocity, and mass fraction of carbon are obtained through numerical simulations. A high current corresponds to a high saturation temperature, evaporation rate, and mass density of carbon clusters. When the carbon vapor is saturated, the saturation temperatures are 3274.9, 3313.9, and 3363.6 K, and the mass densities are 6.4×1022,8.42×1022, and 1.23×1023 m-3 under currents of 150, 200, and 250 A, respectively. A hydrogen-induced marginal growth model is used to explain the growth mechanism. Under a high current, the condensation coefficient and van der Waals force increase owing to the higher saturation temperature and mass density of carbon clusters, which is consistent with experimental results.
基金The Key Research and Development Program of Shandong Province under contact No.2019GHY112063the Breeding Project of Shandong Province under contract No.2019LZGC020+1 种基金the Central Public-interest Scientific Institution Basal Research Fund Chinese Academy of Fishery Sciences under contract Nos 2020XT0601,2020TD19 and 2020TD25the Yellow Sea Fisheries Research Institute Research Fees under contract Nos 20603022019002 and 20603022020015
文摘The mitochondrial genome(mitogenome)of hybrid grouper Epinephelus moara(♀)×Epinephelus tukula(♂),a new hybrid progeny,can provide valuable information for analyzing phylogeny and molecular evolution.In this study,the mitogenome was analyzed using PCR amplification and sequenced,then the phylogenetic relationship of E.moara(♀)×E.tukula(♂)and 35 other species were constructed using Maximum Likelihood and NeighborJoining methods with the nucleotide sequences of 13 conserved protein-coding genes(PCGs).The complete mitogenome of E.moara(♀)×E.tukula(♂)was 16695 bp in length,which contained 13 PCGs,2 rRNA genes,22 tRNA genes,a replication origin and a control region.The composition and order of these genes were consistent with most other vertebrates.Of the 13 PCGs,12 PCGs were encoded on the heavy strand,and ND6 was encoded on the light strand.The mitogenome of the E.moara(♀)×E.tukula(♂)had a higher AT nucleotide content,a positive AT-skew and a negative GC-skew.All protein initiation codons were ATG,except for COX and ND4(GTG),ATP6(CTG),and ND3(ATA).ND2,COXII,ND3,ND4 and Cytb had T as the terminating codon,COXIII’s termination codon was TA,and the remaining PCGs of that were TAA.All tRNA genes,except for the lacking DHU-arm of tRNASer(AGN),were predicted to form a typical cloverleaf secondary structure.In addition,sequence similarity analysis(99%identity)and phylogenetic analysis(100%bootstrap value)indicated that the mitochondrial genome was maternally inherited.This study provides mitogenome data for studying genetic,phylogenetic relationships and breeding of grouper.
基金Supported by Technology Research and Development Plan of the Department of Science and Technology in Hebei Province(11220104D-4)
文摘‘Jinxiu' is a processing apricot(Armeniaca vulgaris L.) cultivar derived from the cross of ‘Chuanzhihong'בJintaiyang'.The fruit is oval-shaped with the ground color of orange and 1/4-1/2 sheet red in the surface. The average fruit weight is65.5 g, and the maximum value is 106 g. The flesh is orange, fine with very less fiber, toughness, less juice and freestone, and tastes sour and sweet. The soluble solid content is 12.5%. The edible rate is 95.8%. The fruit skin hardness is 12.9 kg/cm2 and storable. The preserved apricots have orange color and are tasty. The preserved yield is 40%. The fruit development period is 72 d. The fruit has high yield, and the fruit yield in full fruit period can reach 37 000 kg/hm2. ‘Jinxiu' was examined and approved by Hebei Examination and Approval Committee of Forest Tree Variety in 2013.
基金Project supported by National Natural Science Foundation of China(51764028)Nature Science of Yunnan Province(2016FB080)
文摘In this study,Cu/Ni-La_(0.7)Sr_(0.3)Cr_(0.5)Mn_(0.5)O_(3-δ)(LSCM) catalysts were synthesized via the citric acid-nitrate process(CNP) and chemical co-precipitation. The catalytic performance of Cu/Ni-LSCM catalysts on dry methane reforming was evaluated in a fixed-bed reactor at 550/650 ℃ and atmosphere pressure. Cu/Ni loading was investigated as an influencing factor, which led to 5 cases of samples according to the different Cu/Ni mass ratios. The catalysts were characterized by X-ray diffraction(XRD), field emissionscanning electron microscope(FE-SEM), Brunauer-Emmett-Teller(BET) measurement, X-ray photoelectron spectroscopy(XPS), hydrogen-based temperature-programmed reduction(H_2-TPR) and thermos gravimetric analyzer(TGA). The results show that the methane conversion increases, the resistance against metal sintering increases and the carbon deposition drops after the copper is introduced. This optimum performance can be obtained under Case 3(Cu:Ni:LSCM = 1:3:6 in mass ratio).
基金financially supported by the National Natural Science Foundation of China (Nos.11765010,51704136)the Applied Basic Research Programs of Yunnan Provincial Science and Technology Department (No.2016FB087)the Freely Exploring Fund for Academicians in Yunnan Province (No.2018HA006)
文摘In this study,impurity-free porous graphene(PG) with intrinsic pore structure was synthesized through a facile acid-alkali etching-assisted sonication approach.The pore structure appears on the surface of graphene sheets due to intrinsic defects of graphene.The PG possessed an extremely high specific surface area of 2184 m^2/g,the size of^5 μm and layer numbers of 3-8.Additionally,PG contained micropores and mesopores simultaneously,with an average pore diameter of approximately 3 nm.The effects of acid,alkali,and ultrasound treatment on PG preparation were elucidated by transmission electron microscopy and fourier transform infrared spectroscopy.First,in an acidic solution,oxygen-containing functional groups(hydroxyls,carboxyl,and epoxides) were formed due to the hydrolysis of sulfate and continuous transformations of these functional groups on graphene oxide.Second,under the synergistic effects of alkali and ultrasound treatment,PG was obtained due to the loss of carboxyl and epoxide groups.A new route for preparing PG was provided by the proposed method.
基金supported by the National Natural Science Foundation of China(Grant No.52164050,51762043,61764009,51974143)National Key R&D Program of China(No.2018YFC1901801,No.2018YFC1901805)+1 种基金Major Science and Technology Project of Yunnan Province(202202AB080010,2019ZE00703)Yunnan University“Double First-class”Construction Joint Special Project-major project(202201BF070001-018).
文摘In recent years,a novel PEDOT:PSS/n-Si planar heterojunction solar cell has been extensively studied in the photovoltaic field.Different V_(2)O_(5)-IPA concentrations mixed in PEDOT:PSS samples as hole transport layer were prepared by means of spin coating technique and mechanical mixing of organic and inorganic materials.V_(2)O_(5)was studied for its effects on the surface morphology,chemical composition,and optical transmittance of PEDOT:PSS films.The findings of the study show that the addition of V_(2)O_(5)particles changes the surface morphology of PEDOT:PSS films and promotes its superior ohmic contact with the Si interface.Furthermore,PEDOT:PSS incorporated with V_(2)O_(5)particles that have outstanding optical and semiconductor properties reduces the rate of carrier recombination at the device interface and blocks electron transport to the anode in the fabricated Si-based solar cells.When compared to conventional PEDOT:PSS/Si planar heterojunction solar cells,the fill factor,photoelectric conversion efficiency,open-circuit voltage,and short-circuit current density of the devices prepared in this study can be significantly improved,reaching up to 70.98%,15.17%,652 mV and 32.8 mA/cm^(2),respectively.This research provides a promising and effective method for improving the photoelectric conversion performance of PEDOT:PSS/Si heterojunction solar cells,which enables the application of V_(2)O_(5)in Si solar cells.