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数系结构的探索与发展
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作者 冯进 《常熟理工学院学报》 2007年第4期20-25,共6页
数系是数学中最基本的对象.但最早发展的自然数的基础却迟至19世纪才建立,完整的数系本质结构的认识也经历了一个多世纪.本文从数系结构的探索与发展过程阐述了数学发展的基本特征与规律.
关键词 数系结构 四元 超复
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Investigation on the Optimizing Range of CombustionChamber Configuration Parameters of DSCS 被引量:1
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作者 李向荣 张国栋 魏熔 《Journal of Beijing Institute of Technology》 EI CAS 1998年第2期147-153,共7页
Aim To obtain an optimizing range of the main configuration parameters of double swirls combustion system (DSCS) Methods To analyze the influence of DS combustion cham-ber configuration parameters on fuel spray and mi... Aim To obtain an optimizing range of the main configuration parameters of double swirls combustion system (DSCS) Methods To analyze the influence of DS combustion cham-ber configuration parameters on fuel spray and mixing by means of the fuel jet developmentperiphery charts obtained by the high speed photography with a modeling test device deve-loped by authors,and to examine it by the tests on a single cylinder diesel engine.Resultsand Conclusion The mixing process can be divided into four phases.The optimizing range of the ration of the inner chamber diameter to the cylinder bore,d2/D,is 0.4-0.7; and the outerchamber diameter,d1 the height of the circular ridge to the piston top face,h1,the radius of outer/inner chamber circle,R1,R2 ,the max depth of outer/inner chamber bowl,H1,H2,etc. are also important 展开更多
关键词 diesel engine double swirls combustion system configuration parameter optimizing range
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Research of data architecture in digital ocean
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作者 张峰 李四海 石绥祥 《Marine Science Bulletin》 CAS 2010年第2期85-96,共12页
The characters of marine data, such as multi-source, polymorphism, diversity and large amount, determine their differences from other data. How to store and manage marine data rationally and effectively to provide pow... The characters of marine data, such as multi-source, polymorphism, diversity and large amount, determine their differences from other data. How to store and manage marine data rationally and effectively to provide powerful data support for marine management information system and "Digital Ocean" prototype system construction is an urgent problem to solve. Different types of system planning data, such as marine resource, marine environment, marine econotny and marine management, and establishing marine data architecture frame with uniform standard are to realize the effective management of all level marine data, such as national marine data, the provincial (municipal) marine data, and meet the need of fundamental information-platform construction. 展开更多
关键词 digital ocean data architecture data warehouse data mart METADATA
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Choosing meaningful structure data for improving web search
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作者 郭茜 杨晓春 +1 位作者 于戈 李广翱 《Journal of Southeast University(English Edition)》 EI CAS 2008年第3期343-346,共4页
In order to improve the quality of web search,a new query expansion method by choosing meaningful structure data from a domain database is proposed.It categories attributes into three different classes,named as concep... In order to improve the quality of web search,a new query expansion method by choosing meaningful structure data from a domain database is proposed.It categories attributes into three different classes,named as concept attribute,context attribute and meaningless attribute,according to their semantic features which are document frequency features and distinguishing capability features.It also defines the semantic relevance between two attributes when they have correlations in the database.Then it proposes trie-bitmap structure and pair pointer tables to implement efficient algorithms for discovering attribute semantic feature and detecting their semantic relevances.By using semantic attributes and their semantic relevances,expansion words can be generated and embedded into a vector space model with interpolation parameters.The experiments use an IMDB movie database and real texts collections to evaluate the proposed method by comparing its performance with a classical vector space model.The results show that the proposed method can improve text search efficiently and also improve both semantic features and semantic relevances with good separation capabilities. 展开更多
关键词 WEB SEMANTIC attributes relationship structure data query expansion
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Adsorption Isotherm and Kinetics of Dibenzofuran on Granular Activated Carbons 被引量:7
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作者 李湘 李忠 罗灵爱 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2005年第5期701-704,共4页
The adsorption of dibenzofuran on three commercial granular activated carbons (ACs) was investigated by dynamic experiment to correlate the adsorption equilibrium and kinetics with the structure of activated carbons.P... The adsorption of dibenzofuran on three commercial granular activated carbons (ACs) was investigated by dynamic experiment to correlate the adsorption equilibrium and kinetics with the structure of activated carbons.Physical properties including surface area, average pore diameter, micropore area and micropore volume of the activated carbons were characterized by N2 adsorption experiment on ASAP2010. To calculate the adsorption parameters, adsorption isotherm data were fitted to the Langmuir equation, and adsorption kinetic data were fitted to the linear driving force (LDF) diffusion model. From the correlation results, it is concluded that the adsorption equilibrium and diffusion coefficient of dibenzofuran on activated carbon are controlled respectively by the total adsorbent surface area and the adsorbent pore diameter. 展开更多
关键词 adsorption isotherm diffusion coefficient physical structure DIBENZOFURAN activated carbons
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ANALYTIC STUDY ON POTENTIAL INSTABILITY AND SPIRAL STRUCTURE OF RAIN CLUSTERS 被引量:3
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作者 于杰 张铭 《Journal of Tropical Meteorology》 SCIE 2011年第1期79-86,共8页
This paper presents a study on potential instability and spiral structure of unstable rain clusters.First,we develop a linearized non-axisymmetrical mathematic model for rain clusters in circular cylindrical coordinat... This paper presents a study on potential instability and spiral structure of unstable rain clusters.First,we develop a linearized non-axisymmetrical mathematic model for rain clusters in circular cylindrical coordinates and acquire its analytic solution.Second,we discuss the potential instability of non-axisymmetrical rain clusters.Finally,we conclude that spiral structures can exist in rain clusters.Our analysis indicates that potential instability occurs when humid stratification coefficient is less than zero.Unstable growth rate increases with the increase of the absolute value for humid stratification coefficient.The simpler the vertical structure of perturbation,the thicker the inversion layer;additionally,the smaller the radius of the rain clusters,the larger the unstable growth rate.Simulation results agree well with those from observation and forecast.The spiral structure simulated by our model is similar to a radar echo,suggesting that rain clusters with spiral structures can occur in the atmosphere.In addition,they are generally close to the model solution in this work. 展开更多
关键词 rain clusters mathematic model spiral structure potential instability
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Mechanical response of transmission lines based on sliding cable element 被引量:4
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作者 刘云 钱振东 夏开全 《Journal of Central South University》 SCIE EI CAS 2014年第8期3370-3377,共8页
In order to study the sliding characteristics when the cable is connected with the other rods in the transmission line structures,a linear sliding cable element based on updated Lagrangian formulation and a sliding ca... In order to study the sliding characteristics when the cable is connected with the other rods in the transmission line structures,a linear sliding cable element based on updated Lagrangian formulation and a sliding catenary element considering the out-of-plane stiffness coefficient are put forward.A two-span and a three-span cable structures are taken as examples to verify the sliding cable elements.By comparing the tensions of the two proposed cable elements with the existing research results,the error is less than 1%,which proves the correctness of the proposed elements.The sliding characteristics should be considered in the practical engineering because of the significant difference between the tensions of sliding cable elements and those of cable element without considering sliding.The out-of-plane stiffness coefficient and friction characteristics do not obviously affect the cable tensions. 展开更多
关键词 transmission lines sliding cable element updated Lagrangian formulation geometric nonlinearity mechanical response
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Theoretical Investigations of the Local Structure Distortion and EPR Parameter for Ni2+-doped Perovskite Fluorides
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作者 曹喜民 邝小渝 +1 位作者 李成刚 柴瑞鹏 《Chinese Journal of Chemical Physics》 SCIE CAS CSCD 2011年第2期167-172,I0003,共7页
By analyzing the optical spectra and electron paramagnetic resonance parameter D, the local structure distortion of (NiF6)4- clusters in AMF3 (A=K, Rb; M=Zn, Cd, Ca) and K2ZnF4 series are studied using the complet... By analyzing the optical spectra and electron paramagnetic resonance parameter D, the local structure distortion of (NiF6)4- clusters in AMF3 (A=K, Rb; M=Zn, Cd, Ca) and K2ZnF4 series are studied using the complete energy matrix based on the double spin-orbit coupling parameter model for configuration ions in a tetragonal ligand field. The results indicate that the contribution of ligand to spin-orbit coupling interaction should be considered for our studied systems. Moreover, the relationships between D and the spin-obit coupling coefficients as well as the average parameter and the divergent parameter are discussed. 展开更多
关键词 Complete energy matrix Double spin-orbit coupling parameter model Local structure distortion
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Analysis Expression of Rate Equation for Vertical Cavity Lasers 被引量:1
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作者 PANWei CHENJian-guo 《Semiconductor Photonics and Technology》 CAS 2000年第1期40-47,共8页
An analysis solution of rate equation is derived for vertical cavity surface-emitting lasers. Based on the enhanced spontaneous emission caused by VCSELs and influence of nonradiative recombination, the relation betwe... An analysis solution of rate equation is derived for vertical cavity surface-emitting lasers. Based on the enhanced spontaneous emission caused by VCSELs and influence of nonradiative recombination, the relation between output properties and structural parameters of multi-quantum wells (MQWs) is obtained. It was found that the characteristic curve of a“thresholdless”laser is strongly nonradiative depopulation-dependent. When the nonradiative depopulation is no zero, the light-current characteristic is not linearly even for an ideal closed microcavity. The light output is increased by the enhanced well number and by the reduced width. In particular, a lower threshold current density for MQW structure in the short cavity is realized by us, meanwhile the sharpness of the variation depends on spontaneous emission factor. 展开更多
关键词 Rate equation Spontaneous emission factor Structural parameters of MQWs VCSELS
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A Survey on Smart Collaborative Identifier Networks 被引量:3
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作者 Haifeng Li Hongke Zhang 《China Communications》 SCIE CSCD 2018年第3期168-185,共18页
The current Internet architecture was designed on the basis of a triple bindings model, which could meet the needs of the early Internet. However, with the tremendous growth of the Internet and the continuous innovati... The current Internet architecture was designed on the basis of a triple bindings model, which could meet the needs of the early Internet. However, with the tremendous growth of the Internet and the continuous innovations of applications, the triple bindings(namely, control/data binding, resource/location binding and user/network binding) have given rise to many problems for the Internet, such as scalability, mobility, and security. In order to solve these problems, many network techniques have been developed. Besides, novel future Internet architectures including Information-Centric Networks and Software-Defined Networks have emerged. However, these architectures only partially decouple the triple bindings. To completely separate the triple bindings, Smart Collaborative Identifier Networks(SINET) is proposed. There have been many research efforts on SINET, which built the foundation of SINET being a promising future Internet. In this paper, we comprehensively introduce SINET and these related research works. We start by introducing the motivation for SINET, explain its fundamental concepts and how it can make a difference. Next, we present in details the design principles of every layer in SINET, explaining how it can decouple the triple bindings and solve the problems of the current Internet. Finally, we discuss the state-of-theart challenges in SINET. We investigate the ongoing research works and commercial products in SINET, with aspects such as scalability, mobility, security and reliability. 展开更多
关键词 smart collaborative identifiernetworks future Internet triple bindings scal-ability MOBILITY security reliability
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Bernoulli Numbers & Vandermonde Matrices 被引量:1
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作者 Nick Huo Han Huang 《Journal of Mathematics and System Science》 2016年第2期86-89,共4页
Matrix structuring is a very beautiful way to place Bernoulli numbers, by which a new view to the numbers is opened. Natural Numbers are mathematics seeds and Natural Number System (NNS) breeds the whole world mathe... Matrix structuring is a very beautiful way to place Bernoulli numbers, by which a new view to the numbers is opened. Natural Numbers are mathematics seeds and Natural Number System (NNS) breeds the whole world mathematically. 展开更多
关键词 ALGEBRA Arithmetic Operation Number Process Repeating MATRICES and Determinant.
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A METHODOLOGY FOR INTEGRATED MANAGEMENT SYSTEM
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作者 陈旭球 叶伟雄 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI 1998年第1期111-115,共5页
ISO 9000 certification has been considered as an effective competitive edge for manufacturing industries. In Hong Kong, the ISO 9000 certification has been widely adopted and extended to service industries for the so... ISO 9000 certification has been considered as an effective competitive edge for manufacturing industries. In Hong Kong, the ISO 9000 certification has been widely adopted and extended to service industries for the sole purpose of enhancing corporate image. However, complaints have been voiced by many certified organizations about increasing paperwork, non direct labour and excessive resources channelled into non core business. This paper is to propound the integrated management system, a single management system focusing on business purpose yet being flexible enough to integrate the requirements of various management standards such as the ISO 9000, ISO 14000 and future ISO 18000. This paper describes how the proposed system could be implemented to achieve the desired business results. 展开更多
关键词 quality management integrated management system integrated documentation structure
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Thermo-structural analysis on evaluating effects of friction and transient heat transfer on performance of gears in high-precision assemblies 被引量:3
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作者 Hossein Golbakhshi Moslem Namjoo 《Journal of Central South University》 SCIE EI CAS CSCD 2017年第1期71-80,共10页
The high precision assemblies with considerable radial interference should be accompanied by heating and cooling processes.However,the mechanical properties of metals are greatly affected by thermal operations.So,for ... The high precision assemblies with considerable radial interference should be accompanied by heating and cooling processes.However,the mechanical properties of metals are greatly affected by thermal operations.So,for evaluating the stress distribution and distortion of teeth profiles in a gear/shaft assembly,a transient thermal analysis is necessary for finding the change in mechanical properties.The friction on the contact surface is another important parameter in interaction of the gear with the shaft.Evaluating the gear stress and deformation fields for several modes of heat transfer and friction coefficients showed that the maximum radial or tangential stresses on contact surface of the joint may have more than 8%increase by increasing friction coefficient;while the intensity of heat transfer at cooling stage has lower effect on stress distribution. 展开更多
关键词 friction coefficient transient heat transfer stress field distortion of teeth concurrent analyses
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Wind-induced response analysis of conical membrane structures 被引量:2
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作者 陈波 武岳 沈世钊 《Journal of Harbin Institute of Technology(New Series)》 EI CAS 2005年第5期481-487,共7页
Conical membrane structures are a typical form of tensile membrane structures. In the past, most studies focused on the static performance, but few on dynamic performance. In this paper, systematic parameter analysis ... Conical membrane structures are a typical form of tensile membrane structures. In the past, most studies focused on the static performance, but few on dynamic performance. In this paper, systematic parameter analysis of wind-induced response of conical membrane structures has been performed with nonlinear random simulation method in a time domain, by considering some parameters, such as span, rise-span ratio, prestress of membrane, and characteristic of the approaching wind flow. Moreover, formulas of the dynamic coefficient and nonlinear adjustment factor are advised, which can be conveniently used in wind-resistant design of conical membrane structures. 展开更多
关键词 conical membrane structures wind-induced response the dynamic coefficient nonlinear adjustment factor
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Optimizing pipeline for a RISC processor with multimedia extension ISA 被引量:1
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作者 肖志斌 刘鹏 +1 位作者 姚英彪 姚庆栋 《Journal of Zhejiang University-Science A(Applied Physics & Engineering)》 SCIE EI CAS CSCD 2006年第2期269-274,共6页
The 32-bit extensible embedded processor RISC3200 originating from an RTL prototype core is intended for low-cost consumer multimedia products. In order to incorporate the reduced instruction set and the multimedia ex... The 32-bit extensible embedded processor RISC3200 originating from an RTL prototype core is intended for low-cost consumer multimedia products. In order to incorporate the reduced instruction set and the multimedia extension instruction set in a unifying pipeline, a scalable super-pipeline technique is adopted. Several other optimization techniques are proposed to boost the frequency and reduce the average CPI of the unifying pipeline. Based on a data flow graph (DFG) with delay information, the critical path of the pipeline stage can be located and shortened. This paper presents a distributed data bypass unit and a centralized pipeline control scheme for achieving lower CPI. Synthesis and simulation showed that the optimization techniques enable RISC3200 to operate at 200 MHz with an average CPI of 1.16. The core was integrated into a media SOC chip taped out in SMIC 0.18-micron technology. Preliminary testing result showed that the processor works well as we expected. 展开更多
关键词 PIPELINE RISC Single-instruction-multiple-data (SIMD) Instruction set architecture (ISA) Multimedia extension
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Analysis of Flow Structure and Calculation of Drag Coefficient for Concurrent-up Gas-Solid Flow 被引量:5
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作者 杨宁 王维 +1 位作者 葛蔚 李静海 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2003年第1期79-84,共6页
This study investigates the heterogeneous structure and its influence on drag coefficient for concurrent-up gas-solid flow. The energy-minimization multi-scale (EMMS) model is modified to simulate the variation of str... This study investigates the heterogeneous structure and its influence on drag coefficient for concurrent-up gas-solid flow. The energy-minimization multi-scale (EMMS) model is modified to simulate the variation of structure parameters with solids concentration, showing the tendency for particles to aggregate to form clusters and for fluid to pass around clusters. The global drag coefficient is resolved into that for the dense phase, for the dilute phase and for the so-called inter-phase, all of which can be obtained from their respective phase-specific structure parameters. The computational results show that the drag coefficients of the different phases are quite different, and the global drag coefficient calculated from the EMMS approach is much lower than that from the correlation of Wen and Yu. The simulation results demonstrate that the EMMS approach can well describe the heterogeneous flow structure, and is very promising for incorporation into the two-fluid model or the discrete particle model as the closure law for drag coefficient. 展开更多
关键词 drag coefficient two-phase flow MULTI-SCALE flow structure two-fluid model
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Location of anemometer along Lanzhou-Xinjiang railway 被引量:3
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作者 高广军 张洁 熊小慧 《Journal of Central South University》 SCIE EI CAS 2014年第9期3698-3704,共7页
Using structured mesh to discretize the calculation region, the wind velocity and pressure distribution in front of the wind barrier under different embankment heights are investigated based on the Detached Eddy Simul... Using structured mesh to discretize the calculation region, the wind velocity and pressure distribution in front of the wind barrier under different embankment heights are investigated based on the Detached Eddy Simulation(DES) with standard SpalartAllmaras(SA) model. The Reynolds number is 4.0×105 in this calculation. The region is three-dimensional. Since the wind barrier and trains are almost invariable cross-sections, only 25 m along the track is modeled. The height of embankment ranges from 1 m to 5 m and the wind barrier is 3 m high. The results show that the wind speed changes obviously before the wind barrier on the horizontal plane, which is 4.5 m high above the track. The speed of wind reduces gradually while approaching the wind barrier. It reaches the minimum value at a distance about 5 m before the wind barrier, and increases dramatically afterwards. The speed of wind at this location is linear with the speed of far field. The train aerodynamic coefficients decrease sharply with the increment of the embankment height. And they take up the monotonicity. Meanwhile, when the height increases from 3 m to 5 m, they just change slightly. It is concluded that the optimum anemometer location is nearly 5 m in front of the wind barrier. 展开更多
关键词 anemometer location wind barrier detached eddy simulation wind speed distribution
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The Technology of Data Conversion Among Different DBMSs
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作者 孙适雨 宋瀚涛 梁允荣 《Journal of Beijing Institute of Technology》 EI CAS 1993年第1期83-89,共7页
In the application development of database,sharing information a- mong different DBMSs is an important and meaningful technical subject. This paper analyzes the schema definition and physical organization of popu- lar... In the application development of database,sharing information a- mong different DBMSs is an important and meaningful technical subject. This paper analyzes the schema definition and physical organization of popu- lar relational DBMSs and suggests the use of an intermediary schema.This technology provides many advantages such as powerful extensibility and ease in the integration of data conversions among different DBMSs etc.This pa- per introduces the data conversion system under DOS and XENIX operating systems. 展开更多
关键词 DATABASE database management system data models data structure
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Research and development of a digital design system for hull structures 被引量:3
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作者 ZHAN Yi-ting JI Zhuo-shang LIU Yin-dong 《Journal of Marine Science and Application》 2007年第2期37-43,共7页
Methods used for digital ship design were studied and formed the basis of a proposed frame model suitable for ship construction modeling. Based on 3-D modeling software, a digital design system for hull structures was... Methods used for digital ship design were studied and formed the basis of a proposed frame model suitable for ship construction modeling. Based on 3-D modeling software, a digital design system for hull structures was developed. Basic software systems for modeling, modifying, and assembly simulation were developed. The system has good compatibility, and models created by it can be saved in different 3-D file formats, and 2D engineering drawings can be output directly. The model can be modified dynamically, overcoming the necessity of repeated modifications during hull structural design. Through operations such as model construction, intervention inspection, and collision detection, problems can be identified and modified during the hull structural design stage. Technologies for centralized control of the system, database management, and 3-D digital design are integrated into this digital model in the preliminary design stage of shipbuilding. 展开更多
关键词 digitalized design of ship hull structure ship CAD SOLIDWORKS
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First Principles Investigation of Electronic Property and High Pressure Phase Stability of SrnN
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作者 郝爱民 白静 +1 位作者 罗绍华 齐西伟 《Chinese Journal of Chemical Physics》 SCIE CAS CSCD 2016年第2期219-222,I0001,I0002,共6页
An investigation of electronic property and high pressure phase stability of SmN has been conducted using first principles calculations based on density functional theory. The elec- tronic properties of Stun show a st... An investigation of electronic property and high pressure phase stability of SmN has been conducted using first principles calculations based on density functional theory. The elec- tronic properties of Stun show a striking feature of a half metal, the majority-spin electrons are metallic and the minority-spin electrons are semiconducting. It was found that Stun undergoes a pressure-induced phase transition from NaCl-type (B1) to CsCl-type structure (B2) at 117 GPa. The elastic constants of Stun satisfy Born conditions at ambient pressure, indicating that B1 phase of SmN is mechanically stable at 0 GPa. The result of phonon spectra shows that B1 structure is dynamically stable at ambient pressure, which agrees with the conclusion derived from the elastic constants. 展开更多
关键词 constants First principles calculation Electronic property Phase stability ELASTIC
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