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Zero-field skyrmions in FeGe th.n films stabilized through attach.ng a perpendicularly magnetized single-domain ni layer

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Ch.nese Physics B 2021年第7期30卷 543-550页

作者： zi-bo Zh.ng Yong hu Department of Physics College of SciencesNortheastern UniversityShenyang 110819China State Key Laboratory of Rolling and Automation Northeastern UniversityShenyang 110819China

A numerical study reports that the zero-field skyrmions in Fe Ge th.n films are stabilized wh.n a Fe Ge layer is exch.nge coupled to a single-domain ni layer,which has been magnetized *** to the small thickness,an easy-plane anisotropy in the Fe Ge layer is taken into account,and the skyrmion-crystal state is favored to appear for low anisotropies and intermediate Fe Ge/ni interlayer exch.nge couplings,and finally transformed from a labyrinth-like and into an out-ofplane uniform state for the large couplings or into an in-plane state for the high ***,the maximum skyrmion charge number is bigger for the periodic and fixed boundary conditions with an out-of-plane magnetization;on the contrary,the Bloch-type skyrmions can be frozen and stabilized for the larger couplings on the fixed boundary with an in-plane magnetization,similar to the experimental results of the magnetic-field-induced ***,the skyrmion charge number and diameter both decrease if the nonmagnetic defects exist,and the skyrmion centers are prone to being captured by defect *** work evidences that the ensembles of homochiral skyrmions stabilized in the multilayers fabricated by well-established technologies present a roadmap to design new classes of the materials that can host skyrmions.

关键词： FeGe th.n film zero-field skyrmion interlayer exch.nge coupling Monte Carlo simulation

non-noble metal-based bifunctional electrocatalysts for hydrogen production

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Rare Metals 2022年第7期41卷 2169-2183页

作者： Tong Wu Ming-zi Sun bo-Long huang Department of Applied Biology and Chemical Technology the Hong Kong Polytechnic UniversityHong Kong 999077China

hydrogen is a promising candidate for clean and sustainable energy resources to substitute fossil fuels to mitigate global environmental *** hydrogen production has been regarded as a viable and promising *** overall water splitting is currently the predominant electrochemical hydrogen production method,which could be driven by renewable energy to achieve sustainable ***,the current challenges are the intrinsically sluggish and energy-intensive oxygen evolution reduction(OER)at the anode and the expensive noble metal-based catalysts for overall water splitting,which limit the practical *** efforts have been made to develop bifunctional non-noble metal-based electrocatalysts to boost hydrogen production efficiency and lower the ***,alternative oxidation reactions with faster kinetics and less energy requirement th.n OER are being explored as the anodic reaction to couple with the hydrogen evolution reaction for energy-saving hydrogen *** this review,the non-noble metal-based bifunctional electrocatalysts for overall water splitting,as well as other novel energy-saving hydrogen productions have been introduced and *** challenges and outlooks are commented on at the end of the article.

关键词： Overall water splitting hydrogen production Bifunctional electrocatalyst Energy-saving hydrogen production non-noble metal electrocatalysts

Infinitely Many Solutions for a Class of Fourth Order Elliptic Equations in R^n

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Acta Mathematica Sinica,English Series 2008年第8期24卷 1269-1278页

作者： Min bo YAnG zi Fei Sh.n Department of Mathematics Zhejiang Normal University Jinhua 321004 P. R. China

With the aids of variational method and concentration-compactness principle, infinitely many solutions are obtained for a class of fourth order elliptic equations with singular potentialΔ^2u=μ｜u｜^2＊＊（s）-2u/｜x... 详细信息

关键词： biharmonic operator hardy-Sobolev critical exponent Palais-Smale condition

基于纳秒LIBS的氢气/空气火焰混合分数测量研究

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光谱学与光谱分析 2025年第1期45卷 24-29页

作者：刘子晗刘艳韩磊单沅鲁政高强李帅瑶李博天津大学内燃机燃烧学国家重点实验室天津300072 中国科学院工程热物理研究所北京100190

在双碳政策和化石能源短缺的背景下,氢能作为高效环保的清洁能源,受到广大研究人员的关注。氢气/空气混合燃烧作为推动氢能规模化应用的重要途径,其燃烧机理和关键参数的测量技术成为目前研究的热点。燃空当量比是表征燃烧过程中燃料与... 详细信息

在双碳政策和化石能源短缺的背景下,氢能作为高效环保的清洁能源,受到广大研究人员的关注。氢气/空气混合燃烧作为推动氢能规模化应用的重要途径,其燃烧机理和关键参数的测量技术成为目前研究的热点。燃空当量比是表征燃烧过程中燃料与氧化剂混合程度的重要参数,直接影响燃烧的开始、自持以及燃烧化学反应的活跃程度。因此,对燃烧过程中的局部当量比实时在线监测,对于改善燃烧效率、控制燃烧过程具有重要意义。目前,可以实时测量氢气/空气火焰当量比的方法相对较少,激光光谱技术作为一种非侵入式的测量方法,不仅具有实时在线测量的能力,还具有快速、原位、远程分析、多元素同时在线监测等特点,在燃烧测量领域具有重要的应用潜力。采用纳秒激光诱导击穿光谱技术对氢气和空气燃烧场的燃空当量比进行测量研究。氢气和空气在管内混合后,由射流口喷出形成射流燃烧火焰场。激光通过透镜聚焦到射流燃烧场中击穿并产生等离子体,其等离子体的发射光谱由光谱仪采集,实验发现光谱中h 656 nm和O 777 nm具有很强的发射强度,且光谱强度随着当量比的变化,呈现规律性变化趋势。因此,采用h 656 nm和O 777 nm的光谱分别标示氢气和空气,并将其比值作为燃空当量比的测量参量。实验在氢气空气混合均匀的低速流场中测量了不同当量比下h 656 nm与O 777 nm的光谱强度比值,并与当量比建立标定曲线,实验发现该标定曲线对燃烧场和非燃烧场同样适用。基于标定曲线,我们研究了存在外界掺混情况下,射流燃烧场的局部燃空当量比情况。在当量比1.0,流场速度为20 m·s^(-1)的射流燃烧场中,测量了射流中心位置不同高度的燃空当量比变化情况,并在相同工况下进行了数值模拟。模拟结果与实验测量吻合较好,验证了纳秒激光诱导击穿光谱技术测量氢气/空气混合气的燃空当量比的可行性。该方法可为氢气燃烧基础研究及数值模拟提供技术支持。

关键词：激光诱导击穿光谱氢能当量比模拟

Biomimetic Asymmetric Reduction of Quinazolinones with Chiral and Regenerable nAD(P)h Models

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Ch.nese Journal of Chemistry 2020年第7期38卷 714-718页

作者： zi-Biao Zhao Xiang Li bo Wu Yong-Gui Zhou State Key Laboratory of Catalysis Dalian Institute of Chemical PhysicsChinese Academy of SciencesDalianLiaoning 116023China State Key Laboratory of Organometallic Chemistry Shanghai Institute of Organic ChemistryChinese Academy of SciencesShanghai 200032China

A facile approach to chiral dihydroquinazolinone derivatives has been described wia biomimetic asym-metric reduction of quinazolinones with chiral and regenerable nAD(P)h *** utiity of this method was demonstrated by ... 详细信息

关键词： chiral Chiral conclusion

Diboron-mediated palladium-catalyzed asymmetric transfer hydrogenation using the proton of alcohols as hydrogen source

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Science Ch.na Chemistry 2021年第10期64卷 1743-1749页

作者： bo Wu Jimin Yang Shu-bo hu Ch.ng-Bin Yu zi-Biao Zhao Yi Luo Yong-Gui Zhou Dalian Institute of Chemical Physics Chinese Academy of SciencesDalian 116023China State Key Laboratory of Fine Chemicals School of Chemical EngineeringDalian University of TechnologyDalian 116024China State Key Laboratory of Organometallic Chemistry Shanghai Institute of Organic ChemistryChinese Academy of SciencesShanghai 200032China

The developments of hydrogen sources stand at the forefront of asymmetric reduction. In contrast to the well-studied alcohols as hydrogen sources via β-hydride elimination, the direct utilization of the proton of alcohols as a hydrogen source for activatormediated asymmetric reduction is rarely explored. herein we report the proton of alcohols as a hydrogen source in diboronmediated palladium-catalyzed asymmetric transfer hydrogenation of 1,3-diketones and indoles, providing a series of chiral β-hydroxy ketones and indolines with excellent yields and enantioselectivities. This strategy would be useful for the synthesis of chiral deuterium-labelled compounds due to the ready availability of deuterium-labelled alcohols. Mech.nistic investigations and DFT calculations revealed that active chiral Pd-h species was generated from the proton of alcohols by activating of tetrahydroxydiboron, hydrogen transfer was the rate-determining step, and the reaction preferred Pd(0)-catalyzed mech.nism.

关键词： proton of alcohols hydrogen source asymmetric reduction

Valley-resolved transport in zigzag graph.ne nanoribbon junctions

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Communications in Theoretical Physics 2021年第11期73卷 157-164页

作者： Ming Li zi-Liang Cai Zhi-bo Feng Zh.ng-Yin Zhao College of Science Xuchang UniversityXuchang 461000China

Applying the transfer matrix and Green’s function methods,we study the valley-resolved transport properties of zigzag graph.ne nanoribbon(ZGn_(R))*** width of the left and right ZGn_(R)s are n_(L)and n_(R),and n_(L)≥n_(R).The step/dip positions of the conductance G,the intravalley transmission coefficients(TKKand TK’K’),and the valley polarization efficiency PK’K correspond to the subband edges of the right/left ZGn_(R)that are controlled by n_(R)/n_(L).The intervalley transmission coefficients(TKK and TK’K)exhibit peaks at most of the subband edge of the left and right ZGn_(R)*** the bulk gap of the right ZGn_(R),TKK’=TK’K=0,and PKK’=±1,the valley polarization is well *** n_(R)increases,the energy region for PK’K=±1 *** n_(L)is fixed and n_(R)decreases,G,TKK,TK’K’and PKK’exhibit more and more dips,and the peaks of TKK’(TK’K)become more and more high,especially wh.n(n_(L)-n_(R))/2 is *** characters are quite useful for manipulating the valley dependent transport properties of carriers in ZGn_(R)junctions by modulating n_(L)or n_(R),and our results are helpful to the design of valleytronics based on ZGn_(R)junctions.

关键词： transfer matrix method ZGnR junction valley polarization Landauer-Büttiker formula edge state Fund:supported by the natural Science Foundation of h.nan Province under Grant no.212300410388 the“316”Project Plan of Xuch.ng University

hierarchical self-assembly of crown ether based metal-carbene cages into multiple stimuli-responsive cross-linked supramolecular metallogel

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Science Ch.na Chemistry 2021年第7期64卷 1177-1183页

作者： zi-En Zh.ng Yuan-Yuan An bo Zh.ng Jin-Ping Ch.ng Ying-Feng h.n College of Chemistry and Materials Science Northwest UniversityXi'an 710127China School of Pharmaceutical Sciences Nanjing Tech UniversityNanjing 211816China

The hierarchical self-assembly(hSA) strategy widely utilized in biological systems has been applied in artificial systems to orchestrate small building blocks into complex functional architectures. The non-interfering interactions glue various building blocks together and produce new species with attractive properties. herein, we functionalized nhC-based assemblies with orthogonal host–guest interaction to fabricate metal-carbene based supramolecular polymer gel. A series of unique crown etherappended cylinder-like trinuclear AuIhexacarbene assemblies [Au_(3)(L)_(2)](PF_(6))_(3)(L=D1–D4, A1–A4) were synthesized from the corresponding trisimidazolium salts h_(3)-L(PF_(6))_(3)(L=D1–D4, A1–A4) in which the n-wingtip of the imidazole moieties were substituted with three identical crown ether groups of different sizes(B15C5, B18C6, B21C7, DB24C8). The gold carbene assembly is able to complex six ammonium salts without disrupting the underlying metal-carbene cylinders. In addition, the supramolecular polymer metallogel featuring a multiple-responsiveness can be formed by using [Au_(3)(A_(4))_(2)](PF_(6))_(3) appended with DB24C8 as the core and bisammonium salt as the cross-linker. The case of introducing orthogonal interaction to nhC moiety by n-wingtip substitution demonstrates the feasibility and the power of such strategy to expand the nhC-based supramolecular system and endow them with.novel properties.

关键词： n-heterocyclic carbene metallogel crown ether orthogonal interaction

Laser interference fabrication of large-area functional periodic structure surface

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Frontiers of Mech.nical Engineering 2018年第4期13卷 493-503页

作者： Lei WAnG zi-h.n WAnG Yan-hao YU h.ng-bo SUn State Key Laboratory on Integrated Optoelectronics College of Electronic Science and Engineering Jilin University Changchun 130012 China

Functional periodic structures have attracted significant interest due to their natural capabilities in regulating surface energy, surface effective refractive index, and diffraction. Several technologies are used for the fabrication of these functional structures. The laser interference technique in particular has received attention because of its simplicity, low cost, and high-efficiency fabrication of large-area, micro/nanometer-scale, and periodically patterned structures in air conditions. here, we reviewed the work on laser interference fabrication of large-area functional periodic structures for antireflection, self-cleaning, and superhydrophobicity based on our past and current research. For the common cases, four-beam interference and multi-exposure of two-beam interference were emphasized for their setup, structure diversity, and various applications for antireflection, self-cleaning, and superhydrophobicity. The relations between multi-beam interference and multi-exposure of two-beam interference were compared theoretically and experimentally. nanostructures as a template for growing nanocrystals were also shown to present future possible applications in surface chemical control. Perspectives on future directions and applications for laser interference were presented.

关键词： laser interference four-beam interference multi-exposure of two-beam interference additive fabrication