The genetic mechanism determining amylose content(AC)and its impact on eating and cooking quality(ECQ)of rice is highly complex.To elucidate the genetic basis of AC in rice,the Ting’s core collection was used to iden...The genetic mechanism determining amylose content(AC)and its impact on eating and cooking quality(ECQ)of rice is highly complex.To elucidate the genetic basis of AC in rice,the Ting’s core collection was used to identify novel AC genes/loci through genome-wide association analysis(GWAS)using more than 5.0 million single nucleotide polymorphisms(SNPs).In this study,12 genes related to AC,including the major gene Wx and 11 minor genes,were detected using the EMMAX method.A novel gene,LR,encoding a nucleotide-binding leucine-rich-repeat(LRR)receptor(NLR)family protein,was selected for functional study.When LR was knocked out using CRISPR/Cas9,the AC decreased significantly.Furthermore,the AC in varieties was significantly higher with Haplotype A compared to Haplotypes B and C of LR.Notably,two natural variations,SNP-385(Thr-Hap.A vs Ala-Haps.B and C)and SNP-758(Ser-Hap.A vs Asn-Haps.B and C),in the coding region of LR might play critical roles in regulating AC and serve as potential targets for cultivating rice with diverse amylose contents.展开更多
Since the theoretical potential of urea electrolysis is lower than that of water splitting,urea electrolysis is an ideal method for hydrogen production.In this work,we have synthesized an urchin-like Co-based metal-or...Since the theoretical potential of urea electrolysis is lower than that of water splitting,urea electrolysis is an ideal method for hydrogen production.In this work,we have synthesized an urchin-like Co-based metal-organic framework(Co-MOF)grown on a Co(OH)_(2) template by the gas phase method.As the specific surface area increased and more active sites were exposedcd,the low activity of the bulk MOF for electrocatalytic water splitting was overcome.Through a vulcanization reaction,surface vulcanized Co-MOF(CoS_(x)/Co-MOF)was synthesized.CoS_(x)/Co-MOF as a bifunctional catalyst has good catalytic performance toward the hydrogen evolution reaction(HER),oxygen evolution reaction(OER)and urea oxidation reaction(UOR).Compared with the catalytic activity of the OER,the potential of the UOR only needs 1.315 V(vs.RHE),while the potential of the OER needs 1.51 V(vs.RHE)at 10 mA cm^(-2).The catalytic activity in the urea electrolysis of a CoS_(x)/Co-MOF||CoS_(x)/Co-MOF electrolyzer is much better than that in an alkaline electrolyte.The CoS_(x)/Co-MOF||CoS_(x)/Co-MOF electrolyzer only needs a cell voltage of 1.48 V to achieve a current density of 10 mA cm^(-2) for a urea electrolytic cell in 1.0 M KOH with 0.5 M urea.展开更多
A series of Yb^(3+)/Tm^(3+)co-dopedβ-NaYF_(4)(β-NaYF_(4):Yb,Tm)crystals have been successfully synthesized via the molten salt synthesis(MSS)method.A unique strong green emission of Tm^(3+)was observed,which cannot ...A series of Yb^(3+)/Tm^(3+)co-dopedβ-NaYF_(4)(β-NaYF_(4):Yb,Tm)crystals have been successfully synthesized via the molten salt synthesis(MSS)method.A unique strong green emission of Tm^(3+)was observed,which cannot be obtained by any other method.The red,green and blue(RGB)light emissions have been obtained simultaneously in the presence of a single activator(Tm^(3+)).The influencing factors of crystal growth have been studied in detail,in order to understand the change of the transition probabilities of Tm^(3+).Subsequent studies indicate that the RGB light emissions of Tm^(3+)can be effectively tuned by varying the concentration of sensitizers(Yb^(3+)and Mn^(2+))and the reaction time.Consequently,the effective multicolor upconversion(UC)luminescence was obtained,especially a strong white light,which was not obtained in the β-NaYF_(4):Yb,Tm system earlier.To our knowledge,it is the first time that the UC properties in theβ-NaYF_(4):Yb,Tm system have been investigated by altering the transition probabilities at the same energy level of Tm^(3+).展开更多
A Li-rich layered oxide material of Li_(1.18)Mn_(0.52)Co_(0.15)Ni_(0.15)O_(2) with Li_(3)PO_(4) as an outer modification layer and a spinel as an inner modification layer on the surface of primary particles was synthe...A Li-rich layered oxide material of Li_(1.18)Mn_(0.52)Co_(0.15)Ni_(0.15)O_(2) with Li_(3)PO_(4) as an outer modification layer and a spinel as an inner modification layer on the surface of primary particles was synthesized by a facile synchronous method.A series of physical characterization techniques indicate that Li_(3)PO_(4) and the spinel simultaneously form not only on the surface but also in the bulk of the cathode material during the preparation process.Consequently,a stable protective layer and a highly conductive interlayer are fabricated by the formation of the Li_(3)PO_(4) and spinel phase on the primary particle surface of the cathode material.The modified sample exhibits an improved initial coulombic efficiency of approximately 88.5%.Moreover,the capacity retention of the modified sample increases to 92% after 100 cycles at a rate of 0.2C from 2.0 to 4.8 V compared to that of the pristine sample(62.7%).Moreover,the modified sample also exhibits an excellent rate capability of 171.4 mA h g^(-1) at a 5C rate relative to the pristine sample(134.1 mA h g^(-1)).Our facile modification approach combines the merits of the spinel phase and the Li_(3)PO_(4) compound.Also,our approach can remarkably suppress the structural transformation from layered to spinel-like and decrease the loss of active materials by mitigating the formation of corrosion pits on the particles as well as enhancing the dynamic performance of Li^(+)diffusion of Li-rich layered oxides.展开更多
This article deals with the methods of finding partial discharge(PD)location in power transformers using ultra high frequency(UHF)measurements.The UHF technique utilises two methods to find the PD location,that is,the...This article deals with the methods of finding partial discharge(PD)location in power transformers using ultra high frequency(UHF)measurements.The UHF technique utilises two methods to find the PD location,that is,the shortest path method and hyperbolic method.The shortest path method works based on the comparison of the measured data and the ones in the database.In the hyperbolic method,a hyperbolic equation is obtained between each two element subset of sensors.The coordinate that best fits all equations is known as the PD location,and can be obtained in three different ways,that is,iterative algorithms,the Fang method and Chan method.The convergence of iterative algorithms is limited by poor initial estimate,overshoot,mitigation of non-convergence etc.The Fang and Chan methods are two closed-form solutions that are used in the communication system to find the radiation source location.This article explains how to use these two methods to obtain the PD coordinate inside the power transformer.These two methods can find exactly the coordinate that best fits all hyperbolic equations.At the end of this article,several tests are carried out through CST software and the PD locations is estimated by all presented methods.The simulation results show how the Fang and Chan methods can overcome the limitations of the iterative method.展开更多
Electronic band structure is a cornerstone of condensed matter physics and materials science.Conventional methods like Wannier interpolation(WI),which are commonly used to interpolate band structures onto dense k-poin...Electronic band structure is a cornerstone of condensed matter physics and materials science.Conventional methods like Wannier interpolation(WI),which are commonly used to interpolate band structures onto dense k-point grids,often encounter difficulties with complex systems,such as those involving entangled bands or topological obstructions.We introduce the Hamiltonian transformation(HT)method,a novel framework that enhances interpolation accuracy by localizing the Hamiltonian.Using a pre-optimized transformation,HT produces a far more localized Hamiltonian than WI-SCDM(where Wannier functions are generated via the selected columns of the density matrix projection),achieving up to two orders of magnitude greater accuracy for entangled bands.Although HT utilizes a slightly larger,nonlocal numerical basis set,its construction is rapid and requires no optimization,resulting in significantcomputational speedups.These features make HTamore precise,efficient,and robust alternative to WI-SCDM for band structure interpolation,as verified by high-throughput calculations.展开更多
Rapidly increasing space debris poses a serious threat to space activities.Space nets are promising in removing space debris.The impact response of space nets and space debris is rarely investigated despite its import...Rapidly increasing space debris poses a serious threat to space activities.Space nets are promising in removing space debris.The impact response of space nets and space debris is rarely investigated despite its importance for a successful net capture.In the present paper,a new rhombic-mesh net-based impact dynamic model is established with the appending constraint method.A ground net impact test is conducted to validate the developed model,after which the dynamic characteristics of space net are explored based on numerical simulations.Then,space net capture parameters are firstly analyzed considering impact dynamics.It is found that the impact force during the impact process contributes to net wrapping and net closing,and the tether in the impact area is likely to reach a maximum force value.Moreover,the energy of a space net is transferred drastically,which can well mitigate the impact response during the impact process.As the impact kinetic energy of the space net increases,the observed impact response becomes drastic.Furthermore,the influence of the impact position is examined,showing that an eccentric impact is negatively correlated with net wrapping and closing.展开更多
基金supported by the Hainan Provincial Joint Project of Sanya Yazhou Bay Science and Technology City,China(Grant No.2021JJLH0041)the Zhejiang Provincial Natural Science Foundation,China(Grant No.LY23C130006)+3 种基金the National Natural Science Foundation of China(Grant No.32472207)Nanfan Special Project,Chinese Academy of Agricultural Sciences(Grant Nos.YBXM2436 and YBXM2326)the Hainan Province Science and Technology Special Fund,China(Grant No.ZDYF2022XDNY256)the Innovational Fund for Scientific and Technological Personnel of Hainan Province,China(Grant No.KJRC2023B24).
文摘The genetic mechanism determining amylose content(AC)and its impact on eating and cooking quality(ECQ)of rice is highly complex.To elucidate the genetic basis of AC in rice,the Ting’s core collection was used to identify novel AC genes/loci through genome-wide association analysis(GWAS)using more than 5.0 million single nucleotide polymorphisms(SNPs).In this study,12 genes related to AC,including the major gene Wx and 11 minor genes,were detected using the EMMAX method.A novel gene,LR,encoding a nucleotide-binding leucine-rich-repeat(LRR)receptor(NLR)family protein,was selected for functional study.When LR was knocked out using CRISPR/Cas9,the AC decreased significantly.Furthermore,the AC in varieties was significantly higher with Haplotype A compared to Haplotypes B and C of LR.Notably,two natural variations,SNP-385(Thr-Hap.A vs Ala-Haps.B and C)and SNP-758(Ser-Hap.A vs Asn-Haps.B and C),in the coding region of LR might play critical roles in regulating AC and serve as potential targets for cultivating rice with diverse amylose contents.
基金supported by the National Natural Science Foundation of China(51672056)Excellent Youth Project of Natural Science Foundation of Heilongjiang Province of China(YQ2019B002)the Fundamental Research Funds for the Central Universities.
文摘Since the theoretical potential of urea electrolysis is lower than that of water splitting,urea electrolysis is an ideal method for hydrogen production.In this work,we have synthesized an urchin-like Co-based metal-organic framework(Co-MOF)grown on a Co(OH)_(2) template by the gas phase method.As the specific surface area increased and more active sites were exposedcd,the low activity of the bulk MOF for electrocatalytic water splitting was overcome.Through a vulcanization reaction,surface vulcanized Co-MOF(CoS_(x)/Co-MOF)was synthesized.CoS_(x)/Co-MOF as a bifunctional catalyst has good catalytic performance toward the hydrogen evolution reaction(HER),oxygen evolution reaction(OER)and urea oxidation reaction(UOR).Compared with the catalytic activity of the OER,the potential of the UOR only needs 1.315 V(vs.RHE),while the potential of the OER needs 1.51 V(vs.RHE)at 10 mA cm^(-2).The catalytic activity in the urea electrolysis of a CoS_(x)/Co-MOF||CoS_(x)/Co-MOF electrolyzer is much better than that in an alkaline electrolyte.The CoS_(x)/Co-MOF||CoS_(x)/Co-MOF electrolyzer only needs a cell voltage of 1.48 V to achieve a current density of 10 mA cm^(-2) for a urea electrolytic cell in 1.0 M KOH with 0.5 M urea.
基金supported by the National Sciences Foundation of China(no.21271082 and 21301066).
文摘A series of Yb^(3+)/Tm^(3+)co-dopedβ-NaYF_(4)(β-NaYF_(4):Yb,Tm)crystals have been successfully synthesized via the molten salt synthesis(MSS)method.A unique strong green emission of Tm^(3+)was observed,which cannot be obtained by any other method.The red,green and blue(RGB)light emissions have been obtained simultaneously in the presence of a single activator(Tm^(3+)).The influencing factors of crystal growth have been studied in detail,in order to understand the change of the transition probabilities of Tm^(3+).Subsequent studies indicate that the RGB light emissions of Tm^(3+)can be effectively tuned by varying the concentration of sensitizers(Yb^(3+)and Mn^(2+))and the reaction time.Consequently,the effective multicolor upconversion(UC)luminescence was obtained,especially a strong white light,which was not obtained in the β-NaYF_(4):Yb,Tm system earlier.To our knowledge,it is the first time that the UC properties in theβ-NaYF_(4):Yb,Tm system have been investigated by altering the transition probabilities at the same energy level of Tm^(3+).
基金supported by the National Key Research and Development Program of China(No.2018YFB0104400)the National Natural Science Foundation of China(No.U1764255).
文摘A Li-rich layered oxide material of Li_(1.18)Mn_(0.52)Co_(0.15)Ni_(0.15)O_(2) with Li_(3)PO_(4) as an outer modification layer and a spinel as an inner modification layer on the surface of primary particles was synthesized by a facile synchronous method.A series of physical characterization techniques indicate that Li_(3)PO_(4) and the spinel simultaneously form not only on the surface but also in the bulk of the cathode material during the preparation process.Consequently,a stable protective layer and a highly conductive interlayer are fabricated by the formation of the Li_(3)PO_(4) and spinel phase on the primary particle surface of the cathode material.The modified sample exhibits an improved initial coulombic efficiency of approximately 88.5%.Moreover,the capacity retention of the modified sample increases to 92% after 100 cycles at a rate of 0.2C from 2.0 to 4.8 V compared to that of the pristine sample(62.7%).Moreover,the modified sample also exhibits an excellent rate capability of 171.4 mA h g^(-1) at a 5C rate relative to the pristine sample(134.1 mA h g^(-1)).Our facile modification approach combines the merits of the spinel phase and the Li_(3)PO_(4) compound.Also,our approach can remarkably suppress the structural transformation from layered to spinel-like and decrease the loss of active materials by mitigating the formation of corrosion pits on the particles as well as enhancing the dynamic performance of Li^(+)diffusion of Li-rich layered oxides.
文摘This article deals with the methods of finding partial discharge(PD)location in power transformers using ultra high frequency(UHF)measurements.The UHF technique utilises two methods to find the PD location,that is,the shortest path method and hyperbolic method.The shortest path method works based on the comparison of the measured data and the ones in the database.In the hyperbolic method,a hyperbolic equation is obtained between each two element subset of sensors.The coordinate that best fits all equations is known as the PD location,and can be obtained in three different ways,that is,iterative algorithms,the Fang method and Chan method.The convergence of iterative algorithms is limited by poor initial estimate,overshoot,mitigation of non-convergence etc.The Fang and Chan methods are two closed-form solutions that are used in the communication system to find the radiation source location.This article explains how to use these two methods to obtain the PD coordinate inside the power transformer.These two methods can find exactly the coordinate that best fits all hyperbolic equations.At the end of this article,several tests are carried out through CST software and the PD locations is estimated by all presented methods.The simulation results show how the Fang and Chan methods can overcome the limitations of the iterative method.
基金supported by the Innovation Program for Quantum Science and Technology(2021ZD0303306)the Strategic Priority Research Program of the Chinese Academy of Sciences(XDB0450101)+7 种基金the National Natural Science Foundation of China(22288201,22173093,21688102)the Anhui Provincial Key Research and Development Program(2022a05020052)the National Key Research and Development Program of China(2016YFA0200604,2021YFB0300600)the Network Information Project of Chinese Academy of Sciences(CASWX2021SF-0103)the Hefei National Laboratory for Physical Sciences at the Microscale(KF2020003)National Natural Science Foundation of China(22403024)the Anhui Provincial Natural Science Foundation(2308085QB52)Lin Lin is a Simons Investigator.The authors thank the Hefei Advanced Computing Center,the Supercomputing Center of Chinese Academy of Sciences(Xiandao-1),the Supercomputing Center of USTC,the National Supercomputing Center in Wuxi,Tianjin,Shanghai,and Guangzhou for the computational resources.
文摘Electronic band structure is a cornerstone of condensed matter physics and materials science.Conventional methods like Wannier interpolation(WI),which are commonly used to interpolate band structures onto dense k-point grids,often encounter difficulties with complex systems,such as those involving entangled bands or topological obstructions.We introduce the Hamiltonian transformation(HT)method,a novel framework that enhances interpolation accuracy by localizing the Hamiltonian.Using a pre-optimized transformation,HT produces a far more localized Hamiltonian than WI-SCDM(where Wannier functions are generated via the selected columns of the density matrix projection),achieving up to two orders of magnitude greater accuracy for entangled bands.Although HT utilizes a slightly larger,nonlocal numerical basis set,its construction is rapid and requires no optimization,resulting in significantcomputational speedups.These features make HTamore precise,efficient,and robust alternative to WI-SCDM for band structure interpolation,as verified by high-throughput calculations.
基金funded by“Venture the Sky”Fund Project of National University of Defense Technology.
文摘Rapidly increasing space debris poses a serious threat to space activities.Space nets are promising in removing space debris.The impact response of space nets and space debris is rarely investigated despite its importance for a successful net capture.In the present paper,a new rhombic-mesh net-based impact dynamic model is established with the appending constraint method.A ground net impact test is conducted to validate the developed model,after which the dynamic characteristics of space net are explored based on numerical simulations.Then,space net capture parameters are firstly analyzed considering impact dynamics.It is found that the impact force during the impact process contributes to net wrapping and net closing,and the tether in the impact area is likely to reach a maximum force value.Moreover,the energy of a space net is transferred drastically,which can well mitigate the impact response during the impact process.As the impact kinetic energy of the space net increases,the observed impact response becomes drastic.Furthermore,the influence of the impact position is examined,showing that an eccentric impact is negatively correlated with net wrapping and closing.
