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Chinese Journal of Electronics 2024年第05期33卷 1181-1187页

作者： nan HE Lei WANG Yi TONG College of Electronic and Optical Engineering College of Flexible Electronics (Future Technology) and College of Integrated Circuit Science and Engineering Nanjing University of Posts and Telecommunications Gusu Laboratory of Materials

Three-atoms-type v2C MXene, an emerging class of transition metal carbides, has attracted tremendous attention in the fabrication of advanced memristive devices due to its excellent electrochemical properties. However,the inserted effects and corresponding physical mechanisms of inserting v2C on traditional TiO2-based memristors have not been clearly explored. In this work, exhaustive electrical characterizations of the v2C/TiO2-based devices exhibit enhanced performance（e.g., improved switching stability and lower operating voltages） compared to the TiO2-based counterparts. In addition, the advantaged influences of the inserted v2C have also been studied by means of first-principles calculations, confirming that v2C MXene enables controllable internal ionic process and facilitated formation mechanism of the Ag conductive filaments. This work demonstrates a way to combine experimental and theoretical investigations to reveal the positive effects of introducing v2C MXene on memristor, which is beneficial for fabricating performance-enhanced memristors.

关键词： Performance evaluation Fabrication Memristors Process control Metals Switches Stability analysis Memristor v2C MXene First-principles calculation Switching stability Formation mechanism

Solution-processed rare-earth thulium oxide with high permittivity for low-voltage transistor and inverters applications

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Journal of Rare Earths 2024年第8期42卷 1604-1609,I0007页

作者： Daiming Liu Fei Wang Yongtao Zhang Ya'nan Ding Shandong Engineering Laboratory for Preparation and Application of High-performance Carbon-Materials College of Electromechanical EngineeringQingdao University of Science&TechnologyQingdao266061China College of Electronic and Information Engineering Shandong University of Science and TechnologyQingdao266590China

The use of high-permittivity(high-k) thin films as gate dielectrics is essential in the development of lowpower electronics,In this work,rare-earth thulium oxide(Tm_(2)O_(3)) thin films were prepared by a facile solution process and annealed at various temperatures from 400 to 700℃.The evolution of the physical and dielectric properties of Tm_(2)O_(3) thin film with annealing temperature was *** is demonstrated that the Tm_(2)O_(3) thin film annealed at 600℃ exhibits the optimal performance,including a low leakage current of 3×10^(-10) A/cm^(2),a large areal capacitance of 250 nF/cm^(2) at 100 Hz,and a high permittivity value of *** Tm_(2)O_(3) thin film as a gate insulator was integrated into the thin film transistor(TFT) employing In_(2)O_(3)-based semiconducting *** In_(2)O_(3) TFT with 600℃-annealed Tm_(2)O_(3) dielectric exhibits the superior perfo rmance,with a high I_(on)/I_(off) of 1.65×10^(7),a small subthre shold swing(SS) value of 0.2 v/dec,a v_(TH) of+1.8 v,and a mobility of 1.68 cm^(2)/(v·s).Furthermore,an inverter constructed by connecting the TFT with a resistor exhibits full-swing *** work provides a facile and appealing method for preparing the high-k Tm_(2)O_(3) thin films as alternative gate dielectrics with the potential for use in low-power electronics and logic circuit applications.

关键词： Rare earths Tm_(2)O_(3) Dielectric Transistor Inverter

Ramsey Numbers of Trees versus Multiple Copies of Books

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Acta Mathematicae Applicatae Sinica 2024年第3期40卷 600-612页

作者： Xiao-bing GUO Si-nan HU Yue-jian PENG School of Mathematical Sciences Luoyang Normal UniversityLuoyang 471934China School of Mathematics Hunan UniversityChangsha 410082China

Given two graphs G and H,the Ramsey number R(G,H) is the minimum integer N such that any two-coloring of the edges of K_(N) in red or blue yields a red G or a blue *** v(G) be the number of vertices of G and χ(G) be the chromatic number of *** s(G) denote the chromatic surplus of G,the number of vertices in a minimum color class among all proper χ(G)-colorings of *** showed that R(G,H)≥(v(G)-1)(χ(H)-1)+s(H) if G is connected and v(G)≥s(H).A connected graph G is H-good if R(G,H)=(v(G)-1)(χ(H)-1)+s(H).Let tH denote the disjoint union of t copies of graph H,and let G∨H denote the join of G and *** a complete graph on n vertices by K_(n),and a tree on n vertices by T_(n).Denote a book with n pages by B_(n),i.e.,the join K_(2) ∨■.Erd?s,Faudree,Rousseau and Schelp proved that T_(n) is B_(m)-good if n≥*** this paper,we obtain the exact Ramsey number of T_(n) versus 2B_(2).Our result implies that T_(n) is 2B_(2)-good if n≥5.

关键词： ramsey number ramsey goodness tree book

Quantifying the agreement and accuracy characteristics of four satellite-based LULC products for cropland classification in China

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Journal of Integrative Agriculture 2024年第1期23卷 283-297页

作者： Jie Xue Xianglin Zhang Songchao Chen Bifeng Hu nan Wang Zhou Shi Department of Land Management Zhejiang UniversityHangzhou 310058China Institute of Applied Remote Sensing and Information Technology College of Environmental and Resource SciencesZhejiang UniversityHangzhou 310058China ZJU-Hangzhou Global Scientific and Technological Innovation Center Zhejiang UniversityHangzhou 311215China Department of Land Resource Management School of Public Finance and Public AdministrationJiangxi University of Finance and EconomicsNanchang 330013China Key Laboratory of Data Science in Finance and Economics Jiangxi University of Finance and EconomicsNanchang 330013China Key Laboratory of Spectroscopy Sensing Ministry of Agriculture and Rural AffairsHangzhou 310058China

various land use and land cover(LULC)products have been produced over the past decade with the development of remote sensing *** the differences in LULC classification schemes,there is a lack of research on assessing the accuracy of their application to croplands in a unified ***,this study evaluated the spatial and area accuracies of cropland classification for four commonly used global LULC products(i.e.,MCD12Q1v6,GlobCover2009,FROM-GLC and GlobeLand30)based on the harmonised FAO criterion,and quantified the relationships between four factors(i.e.,slope,elevation,field size and crop system)and cropland classification *** validation results indicated that MCD12Q1 and GlobeLand30 performed well in cropland classification regarding spatial consistency,with overall accuracies of 94.90 and 93.52%,*** FROMGLC showed the worst performance,with an overall accuracy of 83.17%.Overlaying the cropland generated by the four global LULC products,we found the proportions of complete agreement and disagreement were 15.51 and 44.72% for the cropland classification,*** consistency was mainly observed in the Northeast China Plain,the Huang-Huai-Hai Plain and the northern part of the Middle-lower Yangtze Plain,*** contrast,low consistency was detected primarily on the eastern edge of the northern and semiarid region,the Yunnan-Guizhou Plateau and southern *** size was the most important factor for mapping *** area accuracy,compared with China Statistical Yearbook data at the provincial scale,the accuracies of different products in descending order were:GlobeLand30,FROM-GLC,MCD12Q1,and *** cropland classification schemes mainly caused large area deviations among the four products,and they also resulted in the different ranks of spatial accuracy and area accuracy among the four *** results can provide valuable suggestions for selecting cropland products at the national or provinc

关键词： global LULC products cropland mapping accuracy evaluation food security China

Alloy strategy to synthesize Pt-early transition metal oxide interfacial catalysts

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nano Research 2024年第4期17卷 3390-3397页

作者： Shi-Long Xu Hang nan Wanqun Zhang Yue Lin Sheng-Qi Chu Hai-Wei Liang Hefei National Research Center for Physical Sciences at the Microscale Department of ChemistryUniversity of Science and Technology of ChinaHefei 230026China School of Materials and Chemical Engineering Anhui Jianzhu UniversityHefei 230601China Institute of High Energy Physics Chinese Academy of SciencesBeijing 100049China

Metal oxide supported metal catalysts show promising catalytic performance in many industry-relevant ***,the enhancement of performance is often limited by the insufficient metal/metal oxide *** this work,we demonstrate a general synthesis of Pt-early transition metal oxide(Pt-MO_(x),M=Ti,Zr,v,and Y)catalysts with rich interfacial sites,which is based on the air-induced surface segregation and oxidation of M in the supported Pt-M alloy *** characterizations verify the dynamic structural response of Pt-M alloy catalysts to air and the formation of Pt-MO_(x) catalysts with abundant interfacial *** prepared Pt-TiO_(x) interfacial catalysts exhibit improved performance in hydrogenation reactions of benzaldehyde,nitrobenzene,styrene,and furfural,as a result of the heterolytic dissociation of H_(2) at Pt-metal oxide interfacial sites.

关键词： Pt-early transition metal oxide interfacial catalyst alloy oxidation strategy interfacial sites hydrogenation reactions heterolytic dissociation

Strategic regulation of nitrogen-containing intermediates for enhanced nitrate reduction over Co_(3)O_(4)/SiC catalyst having multiple active centers

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Journal of Energy Chemistry 2024年第9期96卷 291-299页

作者： Ming-Hao Guan Hao-nan Xu Jin Liu Tao Wu An-Hui Lu State Key Laboratory of Fine Chemicals Liaoning Key Laboratory for Catalytic Conversion of Carbon ResourcesSchool of Chemical EngineeringDalian University of TechnologyDalian 116024LiaoningChina

Regulating the intermediates involved in the electrocatalytic nitrate reduction reaction(NO_(3)RR)is crucial for the enhancement of reaction ***,it remains a great challenge to regulate the reaction intermediates through active site manipulation on the surface of the ***,a family of n%-Co_(3)O_(4)/SiC(n=5,8,12,20)catalysts with a delicate percentage of Co^(2+)and Co^(3+)were prepared for NO_(3)*** found that Co^(3+)primarily acts as the active site for NO_(3)^(−)reduction to NO_(2)^(−),while Co^(2+)is responsible for the conversion of NO_(2)^(−)to NH_(3).Moreover,the conversion of these intermediates over the active sites is autonomous and separately *** processes synergistically accomplish the reduction of nitrate ions to synthesize *** the experimental studies and density functional theory(DFT)calculations,it is discovered the pathway(^(*)NHO→^(*)NHOH→^(*)NH_(2)OH→^(*)NH_(2)→^(*)NH_(3))is more favorable due to the lowerΔG value(0.25 ev)for the rate-limiting step(^(*)NO→^(*)NHO).The NH_(3)yield rate of 8%-Co_(3)O_(4)/SiC reached 1.08 mmol/(cm^(2)h)with a Faradaic efficiency of 96.4%at−0.89 v versus the reversible hydrogen electrode(RHE),surpassing those of most reported non-noble NO_(3)RR *** strategy not only provides an efficient catalyst for NO_(3)RR but also serves as an illustrative model for the regulation of multi-step reaction intermediates through the design of distinct active sites,thereby presenting a new approach to enhance the efficiency of intricate reactions.

关键词： Electrocatalysis Nitratereduction Co_(3)O_(4)/SiC catalysts Intermediates control

Morphology and phylogenetic placement of Mallomonas vietnamica(Synurales,Chrysophyceae)from China

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Journal of Oceanology and Limnology 2024年第4期42卷 1325-1335页

作者： Junxue HAO Fangru nan Junping LÜ Qi LIU Xudong LIU Shulian XIE Jia FENG School of Life Science Shanxi UniversityTaiyuan 030006China

The newly described chrysophyte,Mallomonas vietnamica,is reported for the first time in China from specimens collected in Guizhou Province,SW *** morphological characteristics were studied using light and scanning electron *** species was described based on morphological characteristics,including cell size,scale size,dome,v-rib,and ***,molecular sequencing of *** was conducted and a phylogenetic tree was constructed based on concatenated SSU,LSU,and rbc L *** phylogenetic tree led us to suggest raising a new section named Uncatusipedae for this *** study provides new molecular data from the genus Mallomonas and enriches our understanding of the species diversity and geographical distribution of the genus Mallomonas in China.

关键词： Chrysophyta Mallomonas vietnamica phylogenetic study taxonomy

Investigating the Effects of vC MXene on Improving the Switching Stability and Reducing the Operation voltages of TiO-Based Memristors

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Chinese Journal of Electronics 2024年

作者： nan HE Lei WANG Yi TONG College of Electronic and Optical Engineering and College of Flexible Electronics (Future Technology) College of Integrated Circuit Science and Engineering Nanjing University of Posts and Telecommunications Gusu Laboratory of Materials

Three-atoms-type v2C MXene, an emerging class of transition metal carbides, has attracted tremendous attention in the fabrication of advanced memristive devices due to its excellent electrochemical properties. However, the inserted and behind physical effects of inserting v2C on traditional TiO2-based memristors have not been clearly explored. In this work, exhaustive electrical characterizations of the v2C/TiO2-based devices exhibit enhanced performance（e.g., improved switching stability and lower operating voltages） compared to the TiO2-based counterparts. In addition, the advantaged influences of the inserted v2C have also been studied by means of firstprinciples calculations, confirming that v2C MXene enables controllable internal ionic process and facilitated formation mechanism of the Ag conductive filaments. This work demonstrates a way to combine experimental and theoretical investigations to reveal the positive effects of introducing v2C MXene on memristor, which is beneficial for fabricating performance-enhanced memristors.

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Toward understanding the microstructure characteristics,phase selection and magnetic properties of laser additive manufactured Nd-Fe-B permanent magnets

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International Journal of Extreme Manufacturing 2024年第1期6卷 277-294页

作者： Bo Yao nan Kang Xiangyu Li Dou Li Mohamed EL Mansori Jing Chen Haiou Yang Hua Tan Xin Lin State Key Laboratory of Solidiffcation Processing Northwestern Polytechnical UniversityXi’anShaanxi 710072People’s Republic of China Arts et Metiers Institute of Technology MSMPHESAM UniversitéF-51006 Chˆalons-en-ChampagneFrance Key Laboratory of Metal High Performance Additive Manufacturing and Innovative Design MIIT ChinaNorthwestern Polytechnical UniversityXi’anShaanxi 710072People’s Republic of China Texas A&M Engineering Experiment Station Institute for Manufacturing SystemsCollege StationTX 77843United States of America

Nd-Fe-B permanent magnets play a crucial role in energy conversion and electronic *** essential magnetic properties of Nd-Fe-B magnets,particularly coercivity and remanent magnetization,are significantly infuenced by the phase characteristics and *** this work,Nd-Fe-B magnets were manufactured using vacuum induction melting(vIM),laser directed energy deposition(LDED)and laser powder bed fusion(LPBF)*** evolution and phase selection of Nd-Fe-B magnets were then clarified in *** results indicated that the solidification velocity(v)and cooling rate(R)are key factors in the phase *** terms of the vIM-casting Nd-Fe-B magnet,a large volume fraction of theα-Fe soft magnetic phase(39.7 vol.%)and Nd2Fe17Bxmetastable phase(34.7 vol.%)areformed due to the low R(2.3×10-1?C s-1),whereas only a minor fraction of the Nd2Fe14B hard magnetic phase(5.15 vol.%)is *** the LDED-processed Nd-Fe-B deposit,although the Nd2Fe14B hard magnetic phase also had a low value(3.4 vol.%)as the values of v(vol.%)is suppressed,and a higher volume of Nd2Fe17Bxmetastable phases(47.5 vol.%)*** a result,both the vIM-casting and LDED-processed Nd-Fe-B deposits exhibited poor magnetic *** contrast,employing the high values of v(>10-2m s-1)and R(1.45×106?C s-1)in the LPBF process resulted in the substantial formation of the Nd2Fe14B hard magnetic phase(55.8 vol.%)directly from the liquid,while theα-Fe soft magnetic phase and Nd2Fe17Bxmetastable phase precipitation are suppressed in the LPBF-processed Nd-Fe-B ***,crystallographic texture analysis reveals that the LPBF-processedNd-Fe-B magnets exhibit isotropic magnetic ***,the LPBF-processed Nd-Fe-B deposit,exhibiting a coercivity of 656 k A m-1,remanence of 0.79 T and maximum energy product of 71.5 k J m-3,achieved an acceptable magnetic perfor

关键词： laser additive manufacturing(LAM) Nd-Fe-B permanent magnets numerical simulation microstructure magnetic properties

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B-L model with D_(4)×Z_(4)×Z_(2)symmetry for fermion mass hierarchies and mixings

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Chinese Physics C 2024年第6期48卷 11-30页

作者： v.v.vien Department of Physics Tay Nguyen UniversityDaklakVietnam

We constructed a gauge B-L model with D_(4)×Z_(4)×Z_(2)symmetry to explain the quark and lepton mass hierarchies and their mixings with realistic CP phases via the type-I seesaw *** quark mases,three quark mixing angles,and the CP phase in the quark sector take the central values whereas Yukawa couplings in the quark sector are diluted in a range of difference of three orders of magnitude by the perturbation theory at the first *** the neutrino sector,a small neutrino mass is achieved by the type-I seesaw *** inverted and normal neutrino mass hierarchies are consistent with the experimental *** predicted sum of neutrino masses for normal and inverted hierarchies,the effective neutrino masses,and the Dirac CP phase are also consistent with recently reported limits.

关键词： flavor symmetries quark and lepton masses and mixing extensions of electroweak gauge sector neutrino mass and mixing non-standard-model neutrinos right-handed neutrinos D4 discrete symmetry