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Chinese Physics Letters 2012年第6期29卷 238-241页

作者： mao han-Qing LI Na CHEN Xi XUE Qi-Kun State Key Laboratory of Low-Dimensional Quantum Physics and Department of Physics Tsinghua UniversityBeijing 100084

Using a home-made Q-plus sensor,simultaneous scanning tunneling microscopy (STM) and atomic force microscopy (AFM) measurements were performed on the wedge-shaped Pb islands grown on Si(111)-7 × *** resolved AFM images were *** contrast of AFM topography shows no dependence on the sample bias (tip is grounded),while the simultaneously obtained tunneling current image exhibits strong bias dependence due to quantum well states (QWS).Furthermore,In the AFM mode,neighboring Pb films with one monolayer (ML) thickness difference within the same Pb island show the same apparent height,which means that the apparent step heights of Pb films oscillate with a bilayer periodicity,being consistent with previous observations by helium atom scattering,x-ray diffraction,and *** possible reasons underlying the oscillation of apparent step heights in AFM topography are discussed.

关键词： apparent tunneling neighboring

Effect of cerium addition on microstructure and mechanical properties of as-cast high grade knives steel

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Journal of Iron and Steel Research International 2022年第12期29卷 1986-1994页

作者： Xi-ya Qiao Xiao han Zhi-jun He Zhen Zhuang Xin Yang Fei-xiong mao School of Materials and Metallurgy University of Science and Technology LiaoningAnshan 114051LiaoningChina Ningbo Key Laboratory of Marine Protection Materials Ningbo Institute of Materials Technology and EngineeringChinese Academy of SciencesNingbo 315201ZhejiangChina

The carbides and mechanical properties of as-cast high grade knives steel with and without cerium(Ce)addition were *** as-cast microstructure of the steel,the size of carbide precipitation,carbide morphology,and mechanical properties were systematically studied through optical microscopy,scanning electron microscopy,and X-ray ***,through the Equilib module of the FactSage thermodynamics software,the changes in the precipitation type of the inclusions with Ce during the solidification of the steel were *** results indicate that the rare earth Ce is added into the steel to refine the as-cast microstructure of the *** types of inclusions in the steel are changed by the addition of *** precipitated carbide morphology changes from a complex rod shape to a relatively single lamellar *** rare earth inclusions formed in steel by a moderate addition of Ce can be severed as the core of heterogeneous nucleation of carbides,which reduce the size of carbide precipitation,promote the uniform distribution of carbide in the as-cast steel,and improve the mechanical properties of the as-cast high grade knives steel.

关键词： Carbide Microstructure Mechanical property Cerium High grade knives steel

A Nano-Micro Engineering Nanofiber for Electromagnetic Absorber,Green Shielding and Sensor

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Nano-Micro Letters 2021年第2期13卷 112-123页

作者： Min Zhang Chen han Wen-Qiang Cao mao-Sheng Cao Hui-Jing Yang Jie Yuan School of Materials Science and Engineering Beijing Institute of TechnologyBeijing 100081People’s Republic of China Department of Physics Tangshan Normal UniversityTangshan 063000People’s Republic of China School of Information Engineering Minzu University of ChinaBeijing 100081People’s Republic of China

It is extremely unattainable for a material to simultaneously obtain efficient electromagnetic(EM)absorption and green shielding performance,which has not been reported due to the competition between conduction loss and ***,by tailoring the internal structure through nano-micro engineering,a NiCo2O4 nanofiber with integrated EM absorbing and green shielding as well as strain sensing functions is *** the improvement of charge transport capability of the nanofiber,the performance can be converted from EM absorption to shielding,or even ***,as the conductivity rising,the reflection loss declines from −52.72 to −10.5 dB,while the EM interference shielding effectiveness increases to 13.4 dB,suggesting the coexistence of the two EM ***,based on the high EM absorption,a strain sensor is designed through the resonance coupling of the patterned NiCo2O4 *** strategies for tuning EM performance and constructing devices can be extended to other EM functional materials to promote the development of electromagnetic driven devices.

关键词： Electromagnetic absorber Electromagnetic shielding NiCo2O4 nanofiber Sensor

The Global Bifurcation of a Cubic System

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Acta Mathematicae Applicatae Sinica 2006年第2期22卷 325-332页

作者： De-sheng Shang mao-an han Jin-ping Sun School of Mathematics and Information Science Shandong University of Technology Zibo 255049 China School of Mathematical Sciences Shanghai Normal University Shanghai 200234 China

In this paper, we study the perturbation of certain of cubic system. By using the method of multi-parameter perturbation theory and qualitative analysis, we infer that the system under consideration can have five limi... 详细信息

关键词： Perturbation bifurcation cubic system limit cycle Homoclinic loop

A novel HfNbTaTiV high-entropy alloy of superior mechanical properties designed on the principle of maximum lattice distortion

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Journal of Materials Science & Technology 2021年第20期79卷 109-117页

作者： Zibing An Shengcheng mao Yinong Liu Li Wang Hao Zhou Bin Gan Ze Zhang Xiaodong han Beijing Key Lab of Microstructure and Property of Advanced Materials Faculty of Materials and ManufacturingBeijing University of TechnologyBeijing100124China Department of Mechanical Engineering The University of Western AustraliaPerthWA6009Australia Nano and Heterogeneous Structural Materials Center School of Materials Science and EngineeringNanjing University of Science and TechnologyNanjing210094China Beijing Key Laboratory of Advanced High Temperature Materials Central Iron and Steel Research InstituteBeijing100081China State Key Laboratory of Silicon Materials Department of Materials Science and EngineeringZhejiang UniversityHangzhou310058China

This paper reports a synergistic design of high-performance BCC high-entropy alloy based on the combined consideration of the principles of intrinsic ductility of elements,maximum atomic size difference for solid solution strengthening and the valence electron concentration criterion for *** single-phase BCC HfNbTaTiV alloy thus designed exhibited a high compressive yield strength of 1350 MPa and a high compressive ductility of>45%at the room *** represents a 50%increase in yield strength relative to a HfNbTaTiZr *** is attributed to the maximized solid solution strengthening effect caused by lattice distortion,which is estimated to be 1094 *** alloy was also able to retain 53%of its yield strength and 77%of its ductility at 700℃.These properties are superior to those of most refractory BCC high-entropy alloys reported in the literature.

关键词： High-entropy alloy Solid solution strengthening Strengthening mechanism Mechanical properties

Effects of Sb Content on Solidification Pathways and Grain Size of AZ91 Magnesium Alloy

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Acta Metallurgica Sinica(English Letters) 2015年第1期28卷 115-121页

作者： Dan-Hui Hou Song-mao Liang Rong-Shi Chen Chuang Dong En-Hou han School of Material Science and Engineering Dalian University of Technology Institute of Metal Research Chinese Academy of Science Institute of Metallurgy Clausthal University of Technology

The phase constitution and solidification pathways of AZ91＋xSb（x = 0, 0.1, 0.5, 1, in wt%） alloys were investigated through ways of microstructure observation, thermal analysis technique, and thermodynamic calculation. It was found that the non-equilibrium solidification microstructure of AZ91＋xSb（x = 0.1, 0.5, 1） is composed of a-Mg matrix, b-Mg17Al12 phase, and intermetallic compound Mg3Sb2. The grain size of the alloys with different Sb contents was quantitatively determined by electron backscattered diffraction technique which shows no grain refinement in Sb-containing AZ91 alloy. Thermodynamic calculations are in reasonable agreement with thermal analysis results, showing that the Mg3Sb2 phase forms after a-Mg nucleation, thus impossible acts as heterogeneous nucleus for a-Mg dendrite. Besides,the solid fraction at dendrite coherency point（fDCPs） determined from thermal analysis decreases slightly with increasing Sb content, which is consistent with the fact that Sb does not refine the grain size of AZ91 alloy.

关键词： Mg–Al–Zn–Sb alloy Solidification pathways Nucleation Grain size Dendrite coherency

Hybrid interference alignment and power allocation for multi-user interference MIMO channels

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Science China(Information Sciences) 2013年第4期56卷 19-27页

作者： SHU Feng YOU XiaoHu WANG mao han YuBing LI Yang SHENG WeiXing Institute of Wireless Communication and Sensor Network EEOTNanjing University of Science and Technology National Mobile Communications Research Laboratory Southeast University Department of Electrical Engineering University of Texas at DallasTX 75080-3021TexasUSA

This paper proposes a hybrid interference alignment scheme which combines maximizing signal-toleakage-noise ratio(Max-SLNR) at transmitter and maximizing signal-to-interference-noise ratio(Max-SINR) at *** proposed scheme gives the same sum rate as the existing method using Max-SINR at both transmitter and receiver by avoiding the operation of reversing channel,thus it provides a simpler ***,two power allocation procedures are devised based on game theory and water *** gain of these schemes over equal power allocation increases to 2 bit/s/Hz in correlated fading channels as large-scale fading becomes ***,user fairness is solved by introducing weighting factors.

关键词： interference alignment power allocation sum rate Max-SLNR Max-SINR

Periodic perturbation of planar systems with a semistable limit cycle

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Chinese Science Bulletin 1997年第4期42卷 265-270页

作者： han mao’anDepartment of Mathematics, Shanghai Jiaotong University, Shanghai 200030, China Department of Mathematics Shanghai Jiaotong University Shanghai China

CONSIDER the following equation: （?）=f（x）+f1（x,λ）+f2（t,x,μ）, （1） where λ, μ are real scalar parameters; f, f1 and f2 are C3 functions in their variables, and f1（x, 0）=0, f2（t, x, 0）=0, f2（t+2π, x, μ）=f+2（t, x, μ）. Suppose that for λ=μ=0, eq. （1） has a semistable limit cycle L of multiple two. The problem is to discuss

关键词： limit cycle invariant torus subharmonic solution.

Latitudinal and interannual variations of the spring phytoplankton bloom peak in the East Asian marginal seas

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Acta Oceanologica Sinica 2016年第12期35卷 81-88页

作者： CHEN Cheng mao Zhihua han Guoqi ZHU Qiankun GONG Fang WANG Tianyu State Key Laboratory of Satellite Ocean Environment Dynamics Second Institute of OceanographyState Oceanic Administration Biological and Physical Oceanography Section Fisheries and Oceans CanadaNorthwest Atlantic Fisheries CentreNewfoundland and Labrador

Combined studies of latitudinal and interannual variations of annual phytoplankton bloom peak in East Asian marginal seas(17°–58°N, including the northern South China Sea(SCS), Kuroshio waters, the Sea of Japan and the Okhotsk Sea) are rarely. Based on satellite-retrieved ten-year(2003–2012) median timing of the annual Chlorophyll a concentration(Chl a) climax, here we report that this annual spring bloom peak generally delays from the SCS in January to the Okhotsk Sea in June at a rate of(21.20±2.86) km/d(decadal median±SD). Spring bloom is dominant feature of the phytoplankton annual cycle over these regions, except for the SCS which features winter bloom. The fluctuation of the annual peak timing is mainly within ±48 d departured from the decadal median peak date, therefore this period(the decadal median peak date ±48 d) is defined as annual spring bloom period. As sea surface temperature rises, earlier spring bloom peak timing but decreasing averaged Chl a biomass in the spring bloom period due to insufficient light is evident in the Okhotsk Sea from 2003 to 2012. For the rest of three study domains, there are no significant interannual variance trend of the peak timing and the averaged Chl a biomass. Furthermore this change of spring phytoplankton bloom timing and magnitude in the Okhotsk Sea challenges previous prediction that ocean warming would enhance algal productivity at high latitudes.

关键词： latitudinal and interannual variation spring bloom peak phytoplankton phenology East Asian marginal seas climate change

Neural-mechanism-driven image block encryption algorithm incorporating a hyperchaotic system and cloud model

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Chinese Physics B 2022年第4期31卷 175-190页

作者： Peng-Fei Fang han Liu Cheng-mao Wu Min Liu School of Automation and Information Engineering Xi’an University of TechnologyXi’an 710048China School of Electronic Engineering Xi’an University of Posts&TelecommunicationsXi’an 710061China School of Engineering and Computer Science Australian National UniversityCanberra 0200Australia

An image encryption algorithm is proposed in this paper based on a new four-dimensional hyperchaotic system,a neural mechanism,a Galois field and an improved Feistel block structure,which improves the efficiency and enhances the security of the encryption ***,a four-dimensional hyperchaotic system with a large key space and chaotic dynamics performance is proposed and combined with a cloud model,in which a more complex and random sequence is constructed as the key stream,and the problem of chaotic periodicity is ***,the key stream is combined with the neural mechanism,Galois field and improved Feistel block structure to scramble and diffuse the image ***,the experimental results and security analysis show that the encryption algorithm has a good encryption effect and high encryption efficiency,is secure,and can meet the requirements of practical applications.

关键词： image encryption neural mechanism hyperchaotic system