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Science China Earth Sciences 2004年第1期47卷 68-77页

作者： liu Jinling WANG weiming Nanjing Institute of Geology and Palaeontology Chinese Academy of Sciences Nanjing 210008 China Nanjing Institute of Geology and Palaeontology Chinese Academy of Sciences Nanjing 210008 China

This paper inspects the relationship between Homo erectus from Beijing, Nanjing and Chenjiawo on the viewpoint of environmental variations. Pieces of evidence show that Nanjing and Chenjiawo Homo erectus lived in glacial age at the Marine Oxygen Isotope Stage (MIS) 16, while Homo erectus pekinensis in major interglacial age at MlSs 15-13. It is also recovered that the cave deposits in Tangshan, Nanjing, and Zhoukoudian, Beijing, as well as the deposits at the Homo erectus site in Chenjiawo, have undergone some similar development process. All of them originated from early-middle Middle Pleistocene, and have gone through the test of the major glacial age at MIS 16 and the major interglacial period at the paleosol stage S5. At the same time, they were also closely connected with some environment events, such as the uplift of the Qinghai-Xizang Plateau, the formation of glaciations and the loess accumulations.

关键词： Homo erectus from Beijing, Nanjing and Chenjiawo, climate and environment, comprehensive comparisons.

Existence of positive solutions with peaks on a Clifford torus for a fractional nonlinear Schrodinger equation

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Science China Mathematics 2019年第9期62卷 1731-1748页

作者： weiming liu Lu Gan School of Mathematics and Statistics Hubei Normal University

We consider the fractional nonlinear Schr?dinger equation in this paper. Applying the finite reduction method, we prove that the equation has positive solutions with peaks on a Clifford torus under some suitable condi... 详细信息

关键词： fractional nonlinear Schrodinger equation reduction method Clifford torus

High-resolution anisotropy of magnetic susceptibility record in the central Chinese Loess Plateau and its paleoenvironment implications

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Science China Earth Sciences 2012年第3期55卷 488-494页

作者： liu weiming SUN JiMin Key Laboratory of Cenozoic Geology and Environment Institute of Geology and GeophysicsChinese Academy of SciencesBeijing 100029China Key Laboratory of Mountain Hazards and Earth Surface Process Institute of Mountain Hazards and EnvironmentChinese Academy of SciencesChengdu 610041China

We analyze high-resolution anisotropy of magnetic susceptibility (AMS) of the loess-paleosol successions at Luochuan, central Chinese Loess Plateau, in order to investigate the AMS characteristics and their climatic implications. Our results indicate a normal sedimentary magnetic fabric for almost of all samples, characterized by minimum susceptibility axes grouped in an almost vertical direction. Magnetic foliation and anisotropy degree show upwards decreasing trend due to decreasing post-depositional compaction. Magnetic lineations show no preferred directions and thus cannot indicate paleowind patterns. AMS parameters at Luochuan are controlled by particle size, pedogenesis, and sedimentary compaction. The high peaks of magnetic foliation and anisotropy degree of L2, L3, L6, L9, and L15 correspond to the coarse particle sizes of these loess beds, indicating the grain-size dependence of AMS.

关键词： Chinese loess anisotropy of magnetic susceptibility Quaternary Luochuan

Hydro-climatic Characteristics of Yarlung Zangbo River Basin since the Last Glacial Maximum

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Advances in Atmospheric Sciences 2022年第3期39卷 415-426页

作者： Shuang liu Kaiheng HU weiming liu Paul A.CARLING Institute of Mountain Hazards and Environment Chinese Academy of SciencesChengdu 610041China Geography&Environment University of SouthamptonHighfieldSouthamptonSO171BJUK

Global climate changes significantly impact the water condition of big rivers in glacierized high mountains. However,there is a lack of studies on hydrological changes within river basins caused by climate changes over a geological timescale due to the impossibility of direct observations. In this study, we examine the hydro-climatic variation of the Yarlung Zangbo River Basin in the Tibet Plateau since the Last Glacial Maximum(LGM) by combining δ18 O proxy records in Indian and Omani caves with the simulated Indian summer monsoon, surface temperature, precipitation, evapotranspiration and runoff via the Community Climate System Model and the reconstructed glacier coverage via the Parallel Ice Sheet Model. The mean river runoff was kept at a low level of 145 billion cubic meters per year until an abrupt increase at a rate of 8.7 million cubic meters per year in the B?lling-Aller?d interval(BA). The annual runoff reached a maximum of 250 billion cubic meters in the early Holocene and then reduced to the current value of 180 billion cubic meters at a rate of 6.4 million cubic meters per year. The low runoff in the LGM and Heinrich Stadial 1(HS1) is likely attributed to such a small contribution of precipitation to runoff and the large glacier cover. The percentage of precipitation to runoff was only 20%during the LGM and HS1. Comparison of glacier area among different periods indicates that the fastest deglaciation occurred during the late HS1, when nearly 60% of glacier area disappeared in the middle reach, 50% in the upper reach,and 30% in the lower reach. The rapid deglaciation and increasing runoff between the late HS1 and BA may have accelerated widespread ice-dam breaches and led to extreme outburst flood events. Combining local geological proxy records and regional simulations could be a useful approach for the study of paleo-hydrologic variations in big river basins.

关键词： Yarlung Zangbo River Basin Indian summer monsoon glacier change runoff variability since the LGM

Dual-functional conductive nanofilm absorber

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Nano Research 2023年第12期16卷 13375-13380页

作者： Hongyan liu Zheng Xie weiming liu Hongdong Li Yue Yan Xiaoli Wang Beijing Institute of Aeronautical Materials Beijing 100095China College of Rare Earth and Faculty of Materials Metallurgy and Chemistry Jiangxi University of Science and TechnologyGanzhou 341000China CAS Key Laboratory of Nanosystem and Hierarchical Fabrication National Center for Nanoscience and TechnologyBeijing 100190China Center of Materials Science and Optoelectronics Engineering University of Chinese Academy of SciencesBeijing 100049China

Converting solar energy by to other forms of energy has attracted a lot of interest from academy to ***,the overall utilization efficiency of solar energy is inferior due to the limited effective solar spectrum ***,in order to utilize the broadband solar spectrum more efficiently,a novel hybrid absorber structure was proposed,which consists of a four-layer planar nanofilm with dual functions of heat absorption and *** average absorption in the visible range is larger than 0.95,and in the near-infrared spectral region,the average absorption is still larger than *** overall absorption of the absorber is over 0.86,while the thermal emittance is lower than 0.04,which can lead to remarkable thermal utilization ***,the full range of the solar irradiance can be utilized by incorporating the photocatalytic TiO_(2) layer into the absorber,which is active in the ultraviolet spectral *** addition to the broadband spectral usage,the virtues of inexpensiveness and environmental friendliness make it a facile alternative to be applied in solar energy transformation.

关键词： absorber photocatalysis multilayer film heat

Advance in Structural Classification and Stability Study of Superamphiphobic Surfaces

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Journal of Bionic Engineering 2023年第1期20卷 366-389页

作者： Haili Zhang Deke Li Jinxia Huang Zhiguang Guo weiming liu Ministry of Education Key Laboratory for the Green Preparation and Application of Functional Materials School of Materials Science and Engineering and Hubei Key Laboratory of Polymer MaterialsHubei UniversityWuhan430062China State Key Laboratory of Solid Lubrication Lanzhou Institute of Chemical PhysicsChinese Academy of SciencesLanzhou730000China School of Materials Engineering Lanzhou Institute of TechnologyLanzhou730050China

Superamphiphobic surfaces have great potential applications in flame resistance,anti-icing,self-cleaning,anti-adhesion,micro-flow control and so ***,the surface durability is poor owing to the limitation of design *** recent years,a lot of efforts have been carried out on the morphology,structure,and stability of superamphiphobic surfaces,resulting in significant improvement in their surface superwetting *** this review,we present a brief classification of the morphological types of superamphiphobic surfaces and summary of the recent progress of researches on the stability of superamphiphobic *** testing methods of mechanical and chemical stability are listed in the article,together with the characteristic results,to provide a better and more detailed understanding of the current research status on superamphiphobic surface stability,which will be of considerable importance as a reference guide for our future *** course,there are still some issues that need to be addressed for the application of superamphiphobic surfaces at large scale,and this is where our future researches will be ***,we discuss the challenges as well as the prospects in the study of superamphiphobic surfaces.

关键词： Superamphiphobicity Structure Morphology Stability

Greedysearch based service location in P2P networks

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Journal of Systems Engineering and Electronics 2005年第4期16卷 886-893页

作者： Zhu Cheng liu Zhong Zhang weiming Yang Dongsheng School of Information Systems and Management National Univ. of Defense Technology Changsha 410073 P. R. China

A model is built to analyze the performance of service location based on greedy search in P2P networks. Hops and relative QoS index of the node found in a service location process are used to evaluate the performance as well as the probability of locating the top 5% nodes with highest QoS level. Both model and simulation results show that, the performance of greedy search based service location improves significantly with the increase of the average degree of the network. It is found that, if changes of both overlay topology and QoS level of nodes can be ignored during a location process, greedy-search based service location has high probability of finding the nodes with relatively high QoS in small number of hops in a big overlay network. Model extension under arbitrary network degree distribution is also studied.

关键词： greedy-search service location P2P network.

CR submanifolds in a sphere and their Gauss maps

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Science China Mathematics 2013年第5期56卷 1041-1049页

作者： CHENG XiaoLiang JI ShanYu liu weiming Department of Mathematics Jilin Normal University Department of Mathematics Capital Normal University Department of Mathematics University of Houston Department of Mathematics and Physics Beijing Institute of Petrochemical Technology

The relationship between CR submanifolds in a sphere and their Gauss maps are *** V be the image of a sphere by a rational holomorphic map F with degree two in another *** is show that the Gauss map of V is degenerate... 详细信息

关键词： CR submanifold Gauss maps

Versatile band structure and electron-phonon coupling in layered PtSe_(2) with strong interlayer interaction

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Nano Research 2022年第7期15卷 6613-6619页

作者： Junbo He Xudan Zhu weiming liu Ertao Hu Jianlu Wang Rongjun Zhang Department of Optical Science and Engineering Fudan UniversityShanghai 200433China College of Electronic and Optical Engineering Nanjing University of Posts and TelecommunicationsNanjing 210023China Institute of Optoelectronics Fudan UniversityShanghai 200433China Academy for Engineering and Technology Fudan UniversityShanghai 200433China Yiwu Research Institute of Fudan University Yiwu 322000China

The large tunability in the band structure is ubiquitous in two-dimensional(2D)materials,and PtSe_(2) is not an exception,which has attracted considerable attention in electronic and optoelectronic applications due to its high carrier mobility and long-term *** dimensional dependent properties are closely related to the evolution of electronic band *** points(CPs),the extrema or saddle points of electronic bands,are the cornerstone of condensed-matter physics and fundamentally determine the optical and transport phenomena of the layered PtSe_(2).Here,we have experimentally revealed the detailed electronic structures in layered PtSe_(2),including the CPs in the Brillouin zones(BZs),by means of reflection contrast spectroscopy and spectroscopic ellipsometry(SE).There are three critical points in the BZs attributed to the excitonic transition,quasi-particle band gap,and the band nesting effect related transition,*** CPs show red-shifting trends with increasing layer number under the mechanism of strong interlayer *** have further revealed the electron–phonon(e–ph)interaction in such layered material,utilizing temperature-dependent absorbance *** strength of e–ph interaction and the average phonon energy also decline with the increasement of layer *** findings give a deep understanding to the physics of the layer-dependent evolution of the electronic structure of PtSe_(2),potentially leading to applications in optoelectronics and electronic devices.

关键词： layered transition metal dichalcogenides PtSe_(2)thin films interlayer coupling critical points electron-phonon interaction

Investigation of Platinum Dispersed on Reduced Graphene Oxide-supported Tungsten Carbide via Sacrificial Cu Adlayers for Methanol Oxidation

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Chinese Journal of Chemistry 2014年第3期32卷 233-240页

作者： Meiqin Shi Di Zhao weiming liu Youqun Chu Chun'an Ma State Key Laboratory Breeding Base of Green Chemistry-Synthesis Technology School of Chemical Engineering and Materials ScienceZhejiang University of TechnologyHangzhouZhejiang 310032China

Reduced graphene oxide-supported tungsten carbide composite(WC/RGO)was prepared by program-con-trolled reduction-carburization *** electron microscope(SEM)and transmission electron micro-scope(TEM)show that WC nanoparticles with a narrow distribution(10-20 nm)are highly dispersed both on the edge and between the layers of *** then it was used as a support to load different low contents(no more than 0.4 wt%)of Pt via sacrificial Cu *** morphology and the electrocatalytic activity of the prepared catalysts were characterized by TEM and cyclic voltammograms(CV),*** results indicate that a small amount of isolated Pt atoms show low or even no activity for methanol *** the increasing deposition cycles,the content of Pt and the ensembles of neighboring Pt atoms are increased,which makes the onset potential shift nega-tively and mass current density *** results demonstrate that controllable amount of Pt can be deposited on WC/RGO by galvanic displacement with Cu,and the extent and domain of Pt loading affect the electrochemical ***,this research also provides another route to prepare a catalyst with ultra low noble metal on WC/RGO for solving the problem of high cost of the catalyst.

关键词： reduced graphene oxide tungsten carbide copper platinum methanol oxidation