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Enhancing Low-Frequency Microwave Absorption Through Structural Polarization Modulation of MXenes

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Nano-Micro Letters 2024年第10期16卷 435-452页

作者： Bo shan Yang Wang Xinyi ji Yi Huang College of Light Industry Science and Engineering State Key Laboratory of Biobased Fiber Manufacturing TechnologyTianjin University of Science and TechnologyTianjin 300457People's Republic of China National Institute for Advanced Materials Tianjin Key Laboratory of Metal and Molecule Based Material ChemistryKey Laboratory of Functional Polymer MaterialsCollaborative Innovation Center of Chemical Science and Engineering(Tianjin)School of Materials Science and EngineeringNankai UniversityTianjin 300350People's Republic of China

Two-dimensional carbon-based materials have shown promising electromagnetic wave absorption capabilities in mid-and high-frequency ranges,but face challenges in low-frequency absorption due to limited control over polarization response mecha-nisms and ambiguous resonance *** this study,we pro-pose a novel approach to enhance absorption efficiency in aligned three-dimensional(3D)MXene/CNF(cellulose nanofibers)cavities by modifying polarization properties and manipulating resonance response in the 3D MXene *** controlled polarization mechanism results in a significant shift of the main absorption region from the X-band to the S-band,leading to a remarkable reflection loss value of-47.9 dB in the low-frequency ***,our findings revealed the importance of the oriented electromagnetic coupling in influencing electromagnetic response and microwave absorption *** present study inspired us to develop a generic strategy for low-frequency tuned absorption in the absence of magnetic element participation,while orientation-induced polarization and the derived magnetic resonance coupling are the key controlling factors of the method.

关键词： Hierarchical structure MXene Microwave absorption Low-frequency

A Seroprevalence Survey of Maedi-Visna Among Twenty-Four Ovine Floks from Twelve Regions of China

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Journal of Integrative Agriculture 2013年第12期12卷 2321-2323页

作者： ZHANG Ke-shan HE ji-jun liu Yong-jie shanG You-jun liu Xiang-tao State Key Laboratory of Veterinary Etiological Biology/National Foot and Mouth Disease Reference Laboratory Lanzhou Veterinary Research InstituteChinese Academy of Agricultural Sciences

Maedi-visna virus（MVV） is an ovine lentivirus that is widespread in many countries *** clinical and subclinical MVV infections cause substantial economic *** infection in live sheep is usually diagnosed serologically,with antibody-positive sheep being regarded as *** have been few reports of maedi-visna in China,with no detailed epidemic analysis of MVV infection in ovine *** order to investigate the seroprevalence and spatial distribution of maedi-visna among ovine flocks in China,a total of 672 serum samples were collected from different ovine flocks in 12 regions（provinces,autonomous regions or municipalities） of China in 2011,and serum antibody levels were determined using a commercial ELISA *** study represents the first investigation of the seroepidemiology of maedi-visna in China,indicating a circulation of MMV among sheep.

关键词： seroprevalence spatial distribution maedi-visna

Effects of Zn content on the microstructure and the mechanical and corrosion properties of as-cast low-alloyed Mg–Zn–Ca alloys

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International Journal of Minerals,Metallurgy and Materials 2018年第7期25卷 800-809页

作者： Hong-xiang Li Shi-kai Qin Hng-zhong Ma jian WanE Yun-jin liu ji-shan Zhang State Key Laboratory for Advanced Metals and Materials University of Science and Technology BeijingBeijing 100083China

The effects of Zn content on the microstxucture and the mechanical and corrosion properties of as-cast low-alloyed Mg-xZn~.2Ca alloys （x = 0.6wt%, 2.0wt%, 2.5wt%, hereafter denoted as 0.6Zn, 2.0Zn, and 2.5Zn alloys, respectively） axe investigated. The results show that the Zn content not only influences grain refinement but also induces different phase precipitation behaviors. The as-cast microstxucture of the 0.6Zn alloy is composed of ct-Mg, Mg2Ca, and Ca2Mg6Zn3 phases, whereas 2.0Zn and 2.5Zn alloys only contain ct-Mg and Ca2Mg6Zn3 phases, as revealed by X-ray diffraction （XRD） and txonsmission electron microscopy （TEM） analyses. Moreover, with in- creasing Zn content, both the ultimate tensile strength （UTS） and the elongation to fracture first increase and then decrease. Among the three investigated alloys, the largest UTS （178 MPa） and the highest elongation to fracture （6.5%） are obtained for the 2.0Zn alloy. In addition, the corrosion rate increases with increasing Zn content. This paper provides on updated investigation of the alloy composi- tion-microstxucture-property relationships of different Zn-containing Mg-Zn-Ca alloys.

关键词： Mg-Zn-Ca alloy s as-cast micro stxucture mechanical properties corrosion properties

Certain Additive Maps on （m ＋ n ＋ 1）-Power Closed Lie Ideals

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Algebra Colloquium 2014年第1期21卷 81-94页

作者： Kun-shan liu Department of Mathematics National Taiwan University Taipei 106 Taiwan

Let R be a prime ring and m, n be fixed non-negative integers such that m＋n ≠ 0. Suppose L is an （m＋m＋1）-power closed Lie ideal, and this means ure＋n＋1 ∈ L for all u ∈ L. If charR = 0 or a prime p 〉 2（m ＋ n）, we characterize the additive maps d： L → R satisfying d（um＋n＋1） = （m -＋n ＋ 1）umd（u）un （resp., d（um＋n＋l） = umd（u）un） for all u ∈ L.

关键词： prime ring k-power closed Lie ideal additive map GPI functional identity

Nonexistence of Type Ⅱ Blowup for Heat Equation with Exponential Nonlinearity

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Chinese Annals of Mathematics,Series B 2019年第2期40卷 309-320页

作者： Ruihong ji shan LI Hui CHEN Geomathematics Key Laboratory of Sichuan Province Chengdu University of Technology Business School Sichuan University

This paper deals with the blowup behavior of the radially symmetric solution of the nonlinear heat equation ut = ?u + e^u in R^N. The authors show the nonexistence of type II blowup under radial symmetric case in the lower supercritical range 3 ≤ N ≤ 9,and give a sufficient condition for the occurrence of type I blowup. The result extends that of Fila and Pulkkinen(2008) in a finite ball to the whole space.

关键词： Nonlinear heat equation Type II blowup Exponential nonlinearity

First record of Bystrowianid Chroniosuchians(Amphibia：Anthracosauromorpha) from the Middle Permian of China

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Acta Geologica Sinica(English Edition) 2017年第5期91卷 1523-1529页

作者： jiANG shan ji Shu-an MO jinyou natural history museum of guangxi Guangxi 530012China institute of geology chinese academy of geological scienceskey laboratory of stratigraphy and paleontologyministry of land and resourcesBeijing 100037China

Chroniosuchians are basal tetrapods owing to Anthracosauromorpha and the oldest species of chroniosuchians have been recorded in the Late Permian of Russia so far. In this study, we present evidence for their existence in the Middle Permian of China, based on well preserved diagnostic vertebrae with associated osteoderms from the Dashankou fanua in northwestern China. The finds clearly show interosteoderm articulation pattern between the adjacent scutes in bystrowianids. The features observed in Yumenerpeton yangi may warrant the close proximity or phyletic succession of the chroniosuchid and bystrowianid types of the osteoderm design.

关键词： Bystrowianidae Chroniosuchia osteoderms Middle Permian China

Generalized Derivations with Periodic Values

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Algebra Colloquium 2015年第1期22卷 163-168页

作者： Kun-shan liu Department of Mathematics National Taiwan University Taipei 106 Taiwan

Let R be a prime ring and n 〉 1 be a fixed positive integer. If g is a nonzero generalized derivation of R such that g（x）n = g（x） for all x ∈ R, then R is commutative except when R is a subring of the 2 × 2 matrix ring over a field. Moreover, we generalize the result to the case g（f（xi））n = g（f（xi）） for all xl,x2,...,xt ∈ R, where f（Xi） is a multilinear polynomial.

关键词： prime ring PI GPI (generalized) derivation

Design and performance study of a dielectric-filled cavity beam current monitor for HUST-PTF

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Nuclear Science and Techniques 2023年第8期34卷 75-85页

作者： ji-Qing Li Kuan-Jun Fan Zheng-Zheng liu jian Wang Qu-shan Chen jin-Feng Yang State Key Laboratory of Advanced Electromagnetic Engineering and Technology School of Electrical and Electronic EngineeringHuazhong University of Science and TechnologyWuhan 430074China The Institute of Scientific and Industrial Research Osaka University8-1 MihogaokaIbarakiOsaka 567-0047Japan

To guarantee the exact proton dose applied to patients and ensure treatment safety while disrupting and destroying tumor cells,it is essential to accurately monitor the proton beam current in real time during patient *** clinical treatment requires a proton beam current in the∼nA range,nondestructive beam current monitors(BCMs)are preferred to minimize the degradation of beam ***,this poses significant challenges in accurately monitoring such extremely low beam *** study proposes a cavity-type BCM equipped with a dielectric plate to reduce its dimensions and achieve sufficient measurement sensitivity for practical requirements.A prototype cavity BCM was fabricated,and off-line testing was performed using a metal wire to simulate the beam to study its *** the simulation and experi-mental results showed that the cavity BCM could measure ultralow proton beam currents with a resolution up to 0.03 nA.

关键词： Proton therapy Beam current Cavity BCM Nondestructive

Study on the preparation of Pt nanocapsules

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International Journal of Minerals,Metallurgy and Materials 2017年第1期24卷 109-114页

作者： Yi-fan Zhang Zhen ji Ke Chen Bo-wen liu Cheng-chang jia shan-wu Yang School of Materials Science and Technology University of Science and Technology BeijingBeijing 100083China

Ag@Pt core-shell nanoparticles（Ag@Pt NPs） were prepared by a co-reduction method. Pt nanocapsules with diameters of less than 10 nm were obtained by an electrochemical method. Cyclic voltammetry（CV） scanning was used to cavitate the Ag@Pt NPs, and the morphology, structure, and cavitation conditions were studied. The results indicate that the effective cavitation conditions to obtain Pt nanoparticles from Ag@Pt NPs are a scanning voltage of 0 to 0.8 V and continuous CV scanning over 2 h. This cavitation method is also applicable for the syntheses of Ir, Ru, and Ru-Pt nanocapsules.

关键词： platinum nanocapsules cavitation preparation methods