Hydrodeoxygenation of furfural(FF)into 2-methylfuran(MF)is a significant biomass utilization route.However,designing efficient and stable non-noble metal catalyst is still a huge challenge.Herein,we reported the N,O c...Hydrodeoxygenation of furfural(FF)into 2-methylfuran(MF)is a significant biomass utilization route.However,designing efficient and stable non-noble metal catalyst is still a huge challenge.Herein,we reported the N,O co-doped carbon anchored with Co nanoparticles(Co-SFB)synthesized by employing the organic ligands with the target heteroatoms.Raman,electron paramagnetic resonance(EPR),electrochemical impedance spectroscopy(EIS),and X-ray photoelectron spectroscopy(XPS)characterizations showed that the co-doping of N and O heteroatoms in the carbon support endows Co-SFB with enriched lone pair electrons,fast electron transfer ability,and strong metal-support interaction.These electronic properties resulted in strong FF adsorption as well as lower apparent reaction activation energy.At last,the obtained N,O co-doped Co/C catalyst showed excellent catalytic activity(nearly 100 mol%FF conversion and 94.6 mol%MF yield)and stability for in-situ dehydrogenation of FF into MF.This N,O co-doping strategy for the synthesis of highly efficient catalytic materials with controllable electronic state will provide an excellent opportunity to better understand the structure-function relationship.展开更多
Anthocyanins, a class of flavonoid compounds that provide pigmentation to plant organs, are beneficial components of the human diet and there is an interest in understanding the regulation of their formation in crop p...Anthocyanins, a class of flavonoid compounds that provide pigmentation to plant organs, are beneficial components of the human diet and there is an interest in understanding the regulation of their formation in crop plants. The apple cultivar ‘May’ represents an excellent model for the study of anthocyanin metabolism due to the spatial color pattern of its flesh, which transitions sequentially from red to white to red again,from the outside to the inside of the apple fruit. To screen the transcription factors involved in the anthocyanin pathway, transcriptomes from differently colored sections of ‘May’ fruits were analyzed by RNA sequencing. Kyoto Encyclopedia of Genes and Genomes(KEGG) database was used to analyse the gene expression data. The results suggested differentially expressed genes(DEGs) that are related to phytohormones are involved in regulating anthocyanin biosynthesis. K-means clustering analysis revealed 167 common DEGs between different sections of fruit with the same expression pattern as candidates for regulating anthocyanin synthesis. Further analysis showed that nine of the 167 DEGs were annotated as transcription factors and quantitative real time PCR(qRT-PCR) confirmed that their expression was obviously higher in red regions of the fruit, consistent with their roles as hub genes that regulate anthocyanin synthesis. This study provides valuable results for future studies of anthocyanin synthesis in apple fruit.展开更多
Great strides have been made towards our understanding of the Universe over the past few decades.Surprisingly,only roughly 5%of what the Universe is made of is in the form of matter that is composed of the elements in...Great strides have been made towards our understanding of the Universe over the past few decades.Surprisingly,only roughly 5%of what the Universe is made of is in the form of matter that is composed of the elements in the periodic table.The other 95% is,at present,completely unknown,and is conveniently referred to as dark matter and dark energy,which certainly represents new physics at work(see,e.g.,Ref.[1]for a review).展开更多
To upgrade the electric properties of lead-free piezoceramics,(1-x)(Ba_(0.98)Ca_(0.02)Ti_(0.94)Sn_(0.04)Zr_(0.02))O_(3)-xY_(2)O_(3)(abbreviated as(1-x)BCTSZ-xY,x=0 mol%,0.02 mol%,0.04 mol%,0.06 mol%,0.08 mol%and 0.1 m...To upgrade the electric properties of lead-free piezoceramics,(1-x)(Ba_(0.98)Ca_(0.02)Ti_(0.94)Sn_(0.04)Zr_(0.02))O_(3)-xY_(2)O_(3)(abbreviated as(1-x)BCTSZ-xY,x=0 mol%,0.02 mol%,0.04 mol%,0.06 mol%,0.08 mol%and 0.1 mol%)ceramics were successfully synthesized by traditional solid-state sintering method.The phase structure and microstructure of ceramics were investigated by X-ray diffraction(XRD),scanning electron microscopy(SEM)and piezoresponse force microscopyeramics(PFM).The electric properties of ceramics were researched through piezoelectric,dielectric and ferroelectric test instruments.The results show that all samples have pure perovskite structure and favorable electric properties.The optimal electric properties which especially include superior ferroelectric properties are gained when Y_(2)O_(3)content is 0.06 mol%(d_(33)=419 pC/N,k_(p)=52%,T_(c)=89.5℃,ε_(r)=26900,tanδ=2.86%,P_(r)=14.41μC/cm^(2),Ec=1.8 kV/cm).Moreover,the temperature-dependent dielectricity of samples shows apparent relaxor behavior under different frequencies.The Curie-Weiss law further proves that all samples are typical relaxor ferroelectrics,and the relaxor degree of samples decreases with increase of Y_(2)O_(3)content.In conclusion,Y_(2)O_(3)plays a significant role in enhancing electric properties of BCTSZ ceramics.展开更多
Hot Universe Baryon Surveyor(HUBS)is a proposed space‐borne observatory for X‐ray astronomy.The primary scientific objectives of the mission are to fill a void in probing the ecosystem of galaxies and thus to advanc...Hot Universe Baryon Surveyor(HUBS)is a proposed space‐borne observatory for X‐ray astronomy.The primary scientific objectives of the mission are to fill a void in probing the ecosystem of galaxies and thus to advance our understanding of galaxy formation and evolution,which is of fundamental importance in cosmology.More specifically,HUBS aims at directly detecting soft X‐ray emission from diffuse gas of temperature exceeding 106 K,which is theoretically postulated to permeate the large structures in the cosmic web and also fill the extended halo of galaxies.However,although some indirect evidence exists,the presence of such hot gas has yet to be well established observationally,due to the lack of effective tools to probe it.In this paper,we describe the design of HUBS,focusing on its scientific payload,which employs superconducting technologies in the detector system,and particularly on progress in the development of superconducting microcalorimeters.展开更多
基金supported by the National Key R&D Program of China(2021YFC2103704)the National Natural Science Foundation of China(22022812,21978259)+1 种基金Key R&D Program of Zhejiang(2022C01208)Institute of Zhejiang University-Quzhou S&T Planed Projects(IZQ2021KJ1001)。
文摘Hydrodeoxygenation of furfural(FF)into 2-methylfuran(MF)is a significant biomass utilization route.However,designing efficient and stable non-noble metal catalyst is still a huge challenge.Herein,we reported the N,O co-doped carbon anchored with Co nanoparticles(Co-SFB)synthesized by employing the organic ligands with the target heteroatoms.Raman,electron paramagnetic resonance(EPR),electrochemical impedance spectroscopy(EIS),and X-ray photoelectron spectroscopy(XPS)characterizations showed that the co-doping of N and O heteroatoms in the carbon support endows Co-SFB with enriched lone pair electrons,fast electron transfer ability,and strong metal-support interaction.These electronic properties resulted in strong FF adsorption as well as lower apparent reaction activation energy.At last,the obtained N,O co-doped Co/C catalyst showed excellent catalytic activity(nearly 100 mol%FF conversion and 94.6 mol%MF yield)and stability for in-situ dehydrogenation of FF into MF.This N,O co-doping strategy for the synthesis of highly efficient catalytic materials with controllable electronic state will provide an excellent opportunity to better understand the structure-function relationship.
基金supported by Key Laboratory of New Technology in Agricultural Application of Beijing and the Beijing Nursery Engineering Research Center for Fruit CropsThe Beijing Technology Innovation Service Capacity Construction-Research Plan (Grant No. KM202010020011)+1 种基金Beijing nova program (Grant No. Z201100006820142)The Construction of Beijing Science and Technology Innovation and Service Capacity in Top Subjects(Grant No. CEFF-PXM2019_014207_000032)。
文摘Anthocyanins, a class of flavonoid compounds that provide pigmentation to plant organs, are beneficial components of the human diet and there is an interest in understanding the regulation of their formation in crop plants. The apple cultivar ‘May’ represents an excellent model for the study of anthocyanin metabolism due to the spatial color pattern of its flesh, which transitions sequentially from red to white to red again,from the outside to the inside of the apple fruit. To screen the transcription factors involved in the anthocyanin pathway, transcriptomes from differently colored sections of ‘May’ fruits were analyzed by RNA sequencing. Kyoto Encyclopedia of Genes and Genomes(KEGG) database was used to analyse the gene expression data. The results suggested differentially expressed genes(DEGs) that are related to phytohormones are involved in regulating anthocyanin biosynthesis. K-means clustering analysis revealed 167 common DEGs between different sections of fruit with the same expression pattern as candidates for regulating anthocyanin synthesis. Further analysis showed that nine of the 167 DEGs were annotated as transcription factors and quantitative real time PCR(qRT-PCR) confirmed that their expression was obviously higher in red regions of the fruit, consistent with their roles as hub genes that regulate anthocyanin synthesis. This study provides valuable results for future studies of anthocyanin synthesis in apple fruit.
基金supported in part by the National Natural Science Foundation of China(11927805)China National Space Administration(CNSA)through a technology development grant。
文摘Great strides have been made towards our understanding of the Universe over the past few decades.Surprisingly,only roughly 5%of what the Universe is made of is in the form of matter that is composed of the elements in the periodic table.The other 95% is,at present,completely unknown,and is conveniently referred to as dark matter and dark energy,which certainly represents new physics at work(see,e.g.,Ref.[1]for a review).
基金Project supported by the Guizhou Province Graduate Research Fund(YJSCXJH2020029)Specialized Funds from Industry and Information Technology Department of Guizhou Province(2016056)+1 种基金the National Natural Science Foundation of China(51602066)High-level Innovative Talents Plan of Guizhou Province((2015)4009)。
文摘To upgrade the electric properties of lead-free piezoceramics,(1-x)(Ba_(0.98)Ca_(0.02)Ti_(0.94)Sn_(0.04)Zr_(0.02))O_(3)-xY_(2)O_(3)(abbreviated as(1-x)BCTSZ-xY,x=0 mol%,0.02 mol%,0.04 mol%,0.06 mol%,0.08 mol%and 0.1 mol%)ceramics were successfully synthesized by traditional solid-state sintering method.The phase structure and microstructure of ceramics were investigated by X-ray diffraction(XRD),scanning electron microscopy(SEM)and piezoresponse force microscopyeramics(PFM).The electric properties of ceramics were researched through piezoelectric,dielectric and ferroelectric test instruments.The results show that all samples have pure perovskite structure and favorable electric properties.The optimal electric properties which especially include superior ferroelectric properties are gained when Y_(2)O_(3)content is 0.06 mol%(d_(33)=419 pC/N,k_(p)=52%,T_(c)=89.5℃,ε_(r)=26900,tanδ=2.86%,P_(r)=14.41μC/cm^(2),Ec=1.8 kV/cm).Moreover,the temperature-dependent dielectricity of samples shows apparent relaxor behavior under different frequencies.The Curie-Weiss law further proves that all samples are typical relaxor ferroelectrics,and the relaxor degree of samples decreases with increase of Y_(2)O_(3)content.In conclusion,Y_(2)O_(3)plays a significant role in enhancing electric properties of BCTSZ ceramics.
基金SifanWang and Yanling Chen also wish to acknowledge support from China Scholarship Coun-cil.This work was supported inpartby National Natural Science Foun-dation of China(NSFC)through Grant 11927805,and by China National Space Administration(CNSA)through a technology develop-ment grant.
文摘Hot Universe Baryon Surveyor(HUBS)is a proposed space‐borne observatory for X‐ray astronomy.The primary scientific objectives of the mission are to fill a void in probing the ecosystem of galaxies and thus to advance our understanding of galaxy formation and evolution,which is of fundamental importance in cosmology.More specifically,HUBS aims at directly detecting soft X‐ray emission from diffuse gas of temperature exceeding 106 K,which is theoretically postulated to permeate the large structures in the cosmic web and also fill the extended halo of galaxies.However,although some indirect evidence exists,the presence of such hot gas has yet to be well established observationally,due to the lack of effective tools to probe it.In this paper,we describe the design of HUBS,focusing on its scientific payload,which employs superconducting technologies in the detector system,and particularly on progress in the development of superconducting microcalorimeters.
