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先天性白内障患者角膜内皮细胞和角膜厚度的研究 预览
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作者 刘劲超 冯丙岂 +3 位作者 苏静静 王施丹 旷龙昊 冯其高 《国际眼科杂志》 CAS 北大核心 2019年第10期1733-1737,共5页
目的:探究先天性白内障患者角膜内皮细胞和角膜厚度的变化规律,为研究该病的特点和机制奠定基础。方法:回顾分析2014-08/2018-12在我院确诊为先天性白内障并住院手术的患者141例,使用非接触型角膜内皮细胞显微镜测量角膜内皮细胞密度(E... 目的:探究先天性白内障患者角膜内皮细胞和角膜厚度的变化规律,为研究该病的特点和机制奠定基础。方法:回顾分析2014-08/2018-12在我院确诊为先天性白内障并住院手术的患者141例,使用非接触型角膜内皮细胞显微镜测量角膜内皮细胞密度(ECD)、平均面积(AVE)、面积标准差(SD)、变异系数(CV)、六边形细胞百分比(Hex)和中央角膜厚度(CCT)。采用偏相关分析评估上述参数与年龄的关系,并使用逐步多元回归分析进行曲线拟合;采用协方差分析比较双眼和单眼患者、不同性别患者上述参数的差异。结果:先天性白内障患者ECD与年龄呈显著负相关,AVE、SD均与年龄呈显著正相关,拟合曲线分别为ECD=3957.33-306.62×ln(年龄)、AVE=178.77+27.39×ln(年龄)和SD=77.13×e^0.013×年龄。女性患者CV显著大于男性(P=0.044)。双眼患者右眼SD和CV明显大于单眼患者患眼(P=0.037、0.028)和健眼(P=0.007、0.003),Hex明显小于单眼患者患眼(P=0.006)和健眼(P=0.009),CCT明显大于单眼患者健眼(P=0.041)。结论:先天性白内障可影响角膜内皮细胞和角膜厚度,尤其对SD、CV、Hex和CCT影响显著,ECD、AVE和SD随年龄的增长而变化,女性患者CV大于男性患者。 展开更多
关键词 先天性白内障 角膜内皮细胞密度 平均面积 面积标准差 变异系数 六边形细胞百分比 中央角膜厚度
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离散纵标六角形节块法及CMFD加速研究 预览
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作者 李志勇 《原子能科学技术》 EI CAS CSCD 北大核心 2019年第2期271-276,共6页
离散纵标节块法是一种求解六角形中子输运方程的有效方法。本文基于六角形横向积分离散纵标方程,解析得到横向积分通量出射通量与入射通量的关系,并根据类似于扩散方法的六角形输运节块中子平衡方程形式,得到了一种离散纵标六角形节块... 离散纵标节块法是一种求解六角形中子输运方程的有效方法。本文基于六角形横向积分离散纵标方程,解析得到横向积分通量出射通量与入射通量的关系,并根据类似于扩散方法的六角形输运节块中子平衡方程形式,得到了一种离散纵标六角形节块法数值迭代策略。由于离散纵标法收敛速度较慢,本文根据粗网有限差分(CMFD)技术导出离散纵标六角形CMFD加速方法。数值计算结果表明,该CMFD加速技术能取得约16倍的加速效果。 展开更多
关键词 六角形 离散纵标法 中子平衡 粗网有限差分方法
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CoO制备及作为锂离子电池负极电化学性能 预览
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作者 潘桂玲 《电源技术》 CAS 北大核心 2019年第10期1601-1604,共4页
采用电解法和水热法合成了具有不同形貌的Co(OH)2前驱物,再经过氩气下烧结后分别制备成球形和六边形形貌的CoO颗粒。其中,电解法制备的CoO呈球形颗粒形貌,颗粒尺寸在140~180nm。水热法制备的CoO呈六边形薄片形态,片状尺寸为500~600nm。... 采用电解法和水热法合成了具有不同形貌的Co(OH)2前驱物,再经过氩气下烧结后分别制备成球形和六边形形貌的CoO颗粒。其中,电解法制备的CoO呈球形颗粒形貌,颗粒尺寸在140~180nm。水热法制备的CoO呈六边形薄片形态,片状尺寸为500~600nm。由于在CoO的六边形薄片形态中,面心立方结构的高密度(111)晶面呈现六边形大表面,故在电化学充放电过程中表现出更多的活性点与较高反应活性。当作为锂离子电池负极材料时,导致六边形薄片的CoO具有呈现出较高的初始容量和良好的稳定性。 展开更多
关键词 锂离子电池 负极材料 电化学 COO 六边形
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六棱柱作细磨介质下磨矿能耗与粒度分布特征 预览
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作者 童佳琪 方鑫 +3 位作者 吴志强 廖宁宁 徐今冬 吴彩斌 《有色金属科学与工程》 CAS 2019年第3期86-91,共6页
六棱柱是一种面接触为主的磨矿介质.以1.18~2.0mm、0.6~1.18mm、0.3~0.6mm 3个粒级样以及实际生产二段沉砂样为研究对象,分别采用等质量的六棱柱和钢锻进行分批次磨矿试验,分析了其磨矿产品的粒度分布和磨矿能耗分布特征,比表面积和体... 六棱柱是一种面接触为主的磨矿介质.以1.18~2.0mm、0.6~1.18mm、0.3~0.6mm 3个粒级样以及实际生产二段沉砂样为研究对象,分别采用等质量的六棱柱和钢锻进行分批次磨矿试验,分析了其磨矿产品的粒度分布和磨矿能耗分布特征,比表面积和体积密度与能耗和t10之间的关系.试验结果表明,六棱柱作为细磨介质,与钢锻相比,磨矿产品也相同的粒度分布规律,符合JK粒度破碎模型.在相同磨矿条件下,六棱柱磨矿生产能力比不上钢锻和钢球.但给料粒度变小,六棱柱磨矿产品中P80和t10值与钢锻的差异也变得越来越小.与此同时,磨矿产品中合格粒级的含量高于钢锻,磨矿的能耗用于矿物的磨细,生成了更多的表面积,矿物的比表面积和能耗关系与磨矿细度与能耗的规律一致,此外矿物的体积密度随着磨矿能耗增加而递减.对于脆性矿物磨矿而言,六棱柱又是比钢锻更加优良的一种细磨介质. 展开更多
关键词 六棱柱 钢锻 磨矿能耗 粒度分布特征 粒度破碎模型
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Parametric study of hexagonal castellated beams in post-tensioned self-centering steel connections
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作者 Hassan ABEDI SARVESTANI 《结构与土木工程前沿:英文版》 EI CSCD 2019年第5期1020-1035,共16页
The effects o f important parameters (beam reinforcing plates, initial post-tensioning, and material properties o f steel angles) on the behavior o f hexagonal castellated beams in post-tensioned self-centering (PTSC)... The effects o f important parameters (beam reinforcing plates, initial post-tensioning, and material properties o f steel angles) on the behavior o f hexagonal castellated beams in post-tensioned self-centering (PTSC) connections undergone cyclic loading up to 4% lateral drift have been investigated by finite element (FE) analysis using ABAQUS. The PTSC connection is comprised o f bolted top and bottom angles as energy dissipaters and steel strands to provide self-centering capacity. The FE analysis has also been validated against the experimental test. The new formulations derived from analytical method has been proposed to predict bending moment o f PTSC connections. The web-post buckling in hexagonal castellated beams has been identified as the dominant failure mode when excessive initial post-tensioning force is applied to reach greater bending moment resistance, so it is required to limit the highest initial post-tensioning force to prevent this failure. Furthermore, properties o f steel material has been simulated using bilinear elastoplastic modeling with 1.5% strain-hardening which has perfectly matched with the real material of steel angles. It is recommended to avoid using steel angles with high yielding strength since they lead to the yielding o f bolt shank. The necessity o f reinforcing plates to prevent beam flange from local buckling has been reaffirmed. 展开更多
关键词 finite element analysis HEXAGONAL castellated beam PARAMETRIC study POST-TENSIONED SELF-CENTERING STEEL connection STEEL moment-resisting frame
Dynamically Tunable Perfect Absorbers Utilizing Hexagonal Aluminum Nano-Disk Array Cooperated with Vanadium Dioxide
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作者 周鹏 郑改革 +2 位作者 陈云云 咸冯林 徐林华 《中国物理快报:英文版》 SCIE CAS CSCD 2019年第1期19-23,共5页
A tunable perfect absorber composed of hexagonal-arranged aluminum nano-disk array embedded in the vanadium dioxide (VO2)film is proposed.The aim is to achieve the tunability of resonance absorption peak in the visibl... A tunable perfect absorber composed of hexagonal-arranged aluminum nano-disk array embedded in the vanadium dioxide (VO2)film is proposed.The aim is to achieve the tunability of resonance absorption peak in the visible and near-infrared regimes.Numerical results reveal that the absorption peak achieves a large tunability of 76.6% while VO2 undergoes a structural transition from insulator phase to metallic phase.By optimizing the structural parameters,an average absorption of 95% is achieved from 1242 to 1815nm at the metallic phase state.In addition,the near unity absorption can be fulfilled in a wide range of incident angle (0°-60°)and under all polarization conditions.The method and results presented here would be beneficial for the design of active optoelectronic devices. 展开更多
关键词 VANADIUM Dioxide HEXAGONAL ALUMINUM nanodisc array ABSORBENT
Hexagonal Patterns in the 2-D Lengyel-Epstein System
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作者 Li-na ZHANG Fei XU 《数学研究及应用:英文版》 CSCD 2019年第3期269-276,共8页
Some qualitative behaviors of stationary solutions for the 2-D Lengyel-Epstein system are considered from the local bifurcation viewpoint in this paper. First, local bifurcation branches of hexagonal stationary soluti... Some qualitative behaviors of stationary solutions for the 2-D Lengyel-Epstein system are considered from the local bifurcation viewpoint in this paper. First, local bifurcation branches of hexagonal stationary solutions are constructed in the special case when the habitat domain is a rectangle. Next, the type of the bifurcation diagram near the bifurcation points is discussed. 展开更多
关键词 Lengyel-Epstein SYSTEM BIFURCATION HEXAGONAL PATTERNS
Plane Analysis for an Inclusion in ID Hexagonal Quasicrys tai Using the Hyp er singular Integral Equation Method
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作者 Fei Lou Ting Cao +1 位作者 Taiyan Qin Chunhui Xu 《固体力学学报:英文版》 SCIE EI CSCD 2019年第2期249-260,共12页
A model of a thin elastic inclusion embedded in an infinite ID hexagonal quasicrystal is discussed. The atomic arrangements of the matrix and the inclusion are both periodic along the xi-direction and quasiperiodic al... A model of a thin elastic inclusion embedded in an infinite ID hexagonal quasicrystal is discussed. The atomic arrangements of the matrix and the inclusion are both periodic along the xi-direction and quasiperiodic along the a;2-direction in the oxiX2-coordinate system. Using the hypersingular integral equation method, the inclusion problem is reduced to solving a set of hypersingular integral equations. Based on the exact analytical solution of the singular phonon and phason stresses near the inclusion front, a numerical method of the hypersingular integral equation is proposed using the finite-part integral method. Finally, the numerical solutions for the phonon and phason stress intensity factors of some examples are given. 展开更多
关键词 Elastic INCLUSION ID HEXAGONAL QUASICRYSTAL Hypersingular integral equations
Synthesis of uniform hexagonal Ag nanoprisms with controlled thickness and tunable surface plasmon bands 预览
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作者 Xing Chen Xun Liu Kai Huang 《矿物冶金与材料学报:英文版》 SCIE EI CAS CSCD 2019年第6期796-802,共7页
In this work,we synthesized monodispersed hexagonal Ag nanoprisms in high yields in a system of poly(vinylpyrrolidone)(PVP)in N-methylpyrrolidone(NMP).A blue shift occurred and was strongly dependent on the thickness ... In this work,we synthesized monodispersed hexagonal Ag nanoprisms in high yields in a system of poly(vinylpyrrolidone)(PVP)in N-methylpyrrolidone(NMP).A blue shift occurred and was strongly dependent on the thickness of the uniform Ag nanoprisms,which had almost the same radial area.When the Ag nanoprisms grew thicker,their in-plane dipole resonance peaks markedly shifted toward shorter wavelengths(i.e.,blue shift).PVP played a critical role of favoring vertical growth of the Ag nanoplates,preventing aggregation,and inducing the formation of Ag hexagonal nanoprisms(HNPs)through the transformation from thin Ag triangular nanoprisms(TNPs).Compared with similar previous research,the present study provides quite uniform Ag hexagonal nanoplates,which makes the blue shift related more solely and distinctly to the thickness of the Ag nanoprisms.The findings of this work provide a new perspective toward understanding the unique optical characteristics of Ag HNPs with different aspect ratios. 展开更多
关键词 HEXAGONAL NANOPRISMS silver NANOPRISMS BLUE SHIFT thickness effect
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Tribological performance of novel nickel-based composite coatings with lubricant particles
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作者 Ignacio TUDELA Andrew J.COBLEY Yi ZHANG 《摩擦(英文版)》 CSCD 2019年第2期169-180,共12页
The present study is focused on the evaluation of the tribological performance of novel Ni/h BN and Ni/WS2 composite coatings electrodeposited from an additive-free Watts bath with the assistance of ultrasound.Lubrica... The present study is focused on the evaluation of the tribological performance of novel Ni/h BN and Ni/WS2 composite coatings electrodeposited from an additive-free Watts bath with the assistance of ultrasound.Lubricated and non-lubricated scratch tests were performed on both novel composite coatings and on standard Ni deposits used as a benchmark coating to have an initial idea of the effect of the presence of particles within the Ni matrix.Under lubricated conditions,the performance of the Ni/h BN composite coating was very similar to the benchmark Ni coating,whereas the Ni/WS2 behaved quite differently,as the latter did not only show a lower coefficient of friction,but also prevented the occurrence of stick-slip motion that was clearly observed in the other coatings.Under non-lubricated conditions,whereas the tribological performance of the Ni/hBN composite coating was again very similar to that of the benchmark Ni coating,the Ni/WS2 composite coatings again showed a remarkable enhancement,as the incorporation of the WS2 particles into the Ni coating not only resulted in a lower coefficient of friction,but also in the prevention of coating failure. 展开更多
关键词 nickel tungsten DISULPHIDE hexagonal BORON NITRIDE composite coatings solid LUBRICANT TRIBOLOGY
Erratum to:Influence of metal support in-plane symmetry on the corrugation of hexagonal boron nitride and graphene monolayers
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作者 Antonio J.Martinez-Galera Jose M.Gomez-Rodriguez 《纳米研究:英文版》 SCIE EI CAS CSCD 2019年第5期1217-1218,共2页
The writings of the text on the last line,left column on the 4^th page and the text on lines 8^th,10^th,11^th and 16^th in the 4^th paragraph,left column and on lines from 1st to 8^th in the 1st paragraph,right column... The writings of the text on the last line,left column on the 4^th page and the text on lines 8^th,10^th,11^th and 16^th in the 4^th paragraph,left column and on lines from 1st to 8^th in the 1st paragraph,right column on the 5^th page,and the text on line 4^th in the 1^st paragraph,left column on the 9^th page,and Fig.3 and its caption on the 5^th page in the original version of this article were unfortunately incorrect. 展开更多
关键词 CORRUGATION hexagonal BORON NITRIDE GRAPHENE monolayers
Water models for interfacial water simulations
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作者 XUE MinMin GUO WanLin 《中国科学:技术科学英文版》 SCIE EI CAS CSCD 2019年第5期729-735,共7页
Interfacial water is of fundamental importance in many technological fields, such as biological processes, chemical reactions and lubrications. A prevalent way to study the structure and dynamics of interfacial water ... Interfacial water is of fundamental importance in many technological fields, such as biological processes, chemical reactions and lubrications. A prevalent way to study the structure and dynamics of interfacial water is carrying out molecular dynamics simulations with empirical potential water models. However, discrepant results have been reported due to their different charge geometries and target properties. Here we investigated the interfacial water structures on smooth surfaces of varying hydrophobicity at low temperatures by comprehensive molecular dynamics simulations with the prevailing water models. It is shown that the choice of the water model can significantly change the water structure on the hydrophilic surface, while has a minor effect on the contact angle on a hydrophobic surface. Furthermore, zero-dimensional ice pyramids and one-dimensional icicles were formed under the regulation of external charges injected to the substrate or imposed electric field, respectively. These results offer new insights into the water structures on different surfaces and reasonable choice of parameters in molecular simulations, and the development of water models. 展开更多
关键词 water models LENNARD-JONES potential hydrogen BONDS SQUARE ICE HEXAGONAL ICE PYRAMIDAL ICE icicle
Special focus on two-dimensional materials and device applications
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作者 Xinran WANG Peng ZHOU 《中国科学:信息科学(英文版)》 SCIE EI CSCD 2019年第12期43-44,共2页
The exploration of two dimensional layered materials(2DLMs)with atomic thickness and rich bandstructures has taken both the scientific and technological communities by storm during the past one and a half decade.Graph... The exploration of two dimensional layered materials(2DLMs)with atomic thickness and rich bandstructures has taken both the scientific and technological communities by storm during the past one and a half decade.Graphene plays a pioneering role in the development of 2DLMs but its gapless bandstructure somehow limits further applications.Following the huge success of graphene,more and more 2DLMs have been discovered and studied,including the transition metal dichalcogenides(TMDs),hexagonal boron nitride(h-BN),black phosphorus(BP),silicene,2D perovskites,etc.So far,the fast pace of TMD material development shows no sign of slow down.More research to pics have been sys tematically explored in various types of 2DLMs,such as quantum transport,spintronics,topological phases,2D magnetism and 2D ferroelectricity. 展开更多
关键词 HEXAGONAL BORON FERROELECTRIC
Whispering-gallery mode hexagonal micro-/nanocavity lasers [Invited]
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作者 Yue-De Yang Min Tang +3 位作者 Fu-Li Wang Zhi-Xiong Xiao Jin-Long Xiao Yong-Zhen Huang 《光子学研究:英文版》 CSCD 2019年第5期594-607,共14页
Whispering-gallery-mode(WGM) hexagonal optical micro-/nanocavities can be utilized as high-quality(Q) resonators for realizing compact-size low-threshold lasers. In this paper, the progress in WGM hexagonal micro-/nan... Whispering-gallery-mode(WGM) hexagonal optical micro-/nanocavities can be utilized as high-quality(Q) resonators for realizing compact-size low-threshold lasers. In this paper, the progress in WGM hexagonal micro-/nanocavity lasers is reviewed comprehensively. High-Q WGMs in hexagonal cavities are divided into two kinds of resonances propagating along hexagonal and triangular periodic orbits, with distinct mode characteristics according to theoretical analyses and numerical simulations;however, WGMs in a wavelength-scale nanocavity cannot be well described by the ray model. Hexagonal micro-/nanocavity lasers can be constructed by both bottom-up and top-down processes, leading to a diversity of these lasers. The ZnO-or nitride-based semiconductor material generally has a wurtzite crystal structure and typically presents a natural hexagonal cross section. Bottom-up growth guarantees smooth surface faceting and hence reduces the scattering loss effectively.Laser emissions have been successfully demonstrated in hexagonal micro-/nanocavities synthesized with various materials and structures. Furthermore, slight deformation can be easily introduced and precisely controlled in top-down fabrication, which allows lasing-mode manipulation. WGM lasing with excellent singletransverse-mode property was realized in waveguide-coupled ideal and deformed hexagonal microcavity lasers. 展开更多
关键词 Whispering-gallery-mode(WGM) high-quality(Q) HEXAGONAL micro- NANOCAVITY LASERS
High-Pressure Behavior of Nano-Pt in Hydrogen Environment
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作者 田灿 黄晓丽 +4 位作者 黄艳萍 李鑫 周迪 王鑫 崔田 《中国物理快报:英文版》 SCIE CAS CSCD 2019年第10期49-52,共4页
We choose nano-Pt in hydrogen environment to explore the size effect on the formation of metal hydrides.At 30 GPa,a phase transition in the metal lattice from the cubic to hexagonal phase is observed characterized by ... We choose nano-Pt in hydrogen environment to explore the size effect on the formation of metal hydrides.At 30 GPa,a phase transition in the metal lattice from the cubic to hexagonal phase is observed characterized by a drastically increased volume per metal atom,indicating the formation of PtH-P63/mmc.We find that nano-Pt could form PtH at a lower pressure than the bulk Pt due to its high specific surface and structure defects.The present work provides the possible route to new metal hydrides under mild conditions. 展开更多
关键词 HEXAGONAL PHASE CUBIC
Hexagonal warping effect on Majorana zero modes at the ends of superconducting vortex lines in doped strong 3D topological insulators
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作者 Chuang Li Lun-Hui Hu Fu-Chun Zhang 《中国科学:物理学、力学、天文学英文版》 SCIE EI CAS CSCD 2019年第11期125-134,共10页
In a superconducting topological insulator, a superconducting vortex line can trap a one-dimensional topological band with localized Majorana zero modes at the ends. Here, we study the effect of hexagonal warping and ... In a superconducting topological insulator, a superconducting vortex line can trap a one-dimensional topological band with localized Majorana zero modes at the ends. Here, we study the effect of hexagonal warping and its corresponding symmetry-breaking effect on vortex phase transition. We perform both analytical calculations based on a semiclassical formula and numerical calculations based on full quantum mechanics using the Bogoliubov-de Gennes equation. We find that the hexagonal warping term extends the topological region of the vortex line as the chemical potential changes and leads to MZMs, even in the absence of topological surface states. 展开更多
关键词 TOPOLOGICAL insulator TOPOLOGICAL SUPERCONDUCTOR vortex phase transition MAJORANA zero modes HEXAGONAL WARPING
二维多孔材料散热器的热分析及结构优化 预览
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作者 梁小林 丁莉 曹海琳 《电子机械工程》 2018年第4期23-26,共4页
为了改善散热性能,文中对某家电产品中PCB板上的散热器进行了热分析及结构优化,在翅片散热器热分析的基础上,对2种二维多孔材料散热器进行了热分析,对比了3种散热器的散热性能。研究表明:在强迫对流散热条件下,与翅片散热器相比较,二... 为了改善散热性能,文中对某家电产品中PCB板上的散热器进行了热分析及结构优化,在翅片散热器热分析的基础上,对2种二维多孔材料散热器进行了热分析,对比了3种散热器的散热性能。研究表明:在强迫对流散热条件下,与翅片散热器相比较,二维多孔材料散热器的散热性能更好;六边形多孔材料散热器比矩形多孔材料散热器的散热性能要好,同时更有利于实现结构的轻量化要求,降低材料成本,提高产品利润。 展开更多
关键词 散热器 二维多孔材料 六边形 轻量化
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平面四孔六边形格网系统编码运算 预览 被引量:2
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作者 王蕊 贲进 +2 位作者 杜灵瑀 周建彬 李祝鑫 《测绘学报》 CSCD 北大核心 2018年第7期1018-1025,共8页
全球离散格网系统是支持多源地球空间信息融合处理的新型数据模型。六边形格网系统具有优良的几何属性,相关研究已引起学术界的关注,单元层次关系描述与编码方案设计是其研究难点。本文根据平面四孔六边形格网系统结构特点,设计“格点... 全球离散格网系统是支持多源地球空间信息融合处理的新型数据模型。六边形格网系统具有优良的几何属性,相关研究已引起学术界的关注,单元层次关系描述与编码方案设计是其研究难点。本文根据平面四孔六边形格网系统结构特点,设计“格点四叉树”层次编码结构,定义编码运算并归纳运算规律,据此实现二维直角坐标与单元编码的相互转换。与同类成果相比,格点四叉树从原理上克服了奇(偶)分层编码、单元中心与顶点混合编码导致的诸多缺陷,且编码运算规律简明,易于算法实现。试验结果表明,格点四叉树编码加法运算的效率约是PYXIS的6倍、HQBS的5倍;直角坐标转换到编码的效率约为HQBS的5倍,编码转换到直角坐标的效率约为HQBS的3倍。 展开更多
关键词 全球离散格网系统 六边形 单元编码 坐标 转换
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双电机异步驱动的三端口级联多电平变换器及再生能量分配系统 被引量:1
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作者 王盼 刘飞 +3 位作者 查晓明 宫金武 冯锟 熊晓琪 《中国电机工程学报》 CSCD 北大核心 2018年第6期1799-1809,共11页
为解决工业现场多电机运行及再生能量利用问题,提出一种可同时驱动双电机异步运行的三端口级联多电平变换器拓扑及控制系统。将传统H桥级联多电平变换器与六边形变换器拓扑结合构成一个三端口AC/AC/AC结构。其中,H桥级联变换器每单元前... 为解决工业现场多电机运行及再生能量利用问题,提出一种可同时驱动双电机异步运行的三端口级联多电平变换器拓扑及控制系统。将传统H桥级联多电平变换器与六边形变换器拓扑结合构成一个三端口AC/AC/AC结构。其中,H桥级联变换器每单元前端通过移相变压器接入电网,作为输入端口;六边形拓扑相邻顶点则构成两交流输出端口。采用恒压频比控制,结合功率分配分析,分别给定两输出端口控制信号,驱动双电机异步运行。六桥臂可等效为两组耦合三相对称电源,将一台电机再生能量转移供给另一台电机的电动运行,以此提出新的能量流动路径,降低单元直流侧电容电压泵升。以12单元6桥臂的三端口级联多电平变换器为例,通过Matlab仿真及实验结果验证了该拓扑及控制策略的可行性和有效性。 展开更多
关键词 三端口级联多电平 六边形 双电机异步运行 功率分配 再生能量利用
Algebraic encoding scheme for aperture 3 hexagonal discrete global grid system
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作者 BEN Jin LI YaLu +2 位作者 ZHOU ChengHu WANG Rui DU LingYu 《中国科学:地球科学英文版》 SCIE EI CAS CSCD 2018年第2期215-227,共13页
分离全球格子系统(DGGS ) 是使用房间的一个层次镶嵌细工划分并且探讨全部地球的空间引用。他们提供允许在为可视化和分析足够的大、可变的 geospatial 数据的多重来源之间的快集成的组织上的结构。尽管有作为优异选择支持六角形的 DGGS... 分离全球格子系统(DGGS ) 是使用房间的一个层次镶嵌细工划分并且探讨全部地球的空间引用。他们提供允许在为可视化和分析足够的大、可变的 geospatial 数据的多重来源之间的快集成的组织上的结构。尽管有作为优异选择支持六角形的 DGGS 的研究的重要身体,它的应用程序被妨碍了未付部分地到有一个有效探讨系统的一个合理层次的缺乏。这篇论文论述为孔 3 编码计划的一个代数学的模型六角形(A3H ) DGGS。第一,一个格子房间的定义,顶点,边,和一个中心镇静,被介绍描述格子的基本元素。由与它的中心识别格子房间,第二,这篇论文证明在不同层次的房间中心能通过在二个连续层次之间的递归的几何关系在复杂飞机完全用一个混合位置的数字系统被代表,它表明格子房间是实质上特殊的复杂根值数字。第三,通过连续奇怪或平的层次的递归的几何关系,混合位置的数字系统能也被使用特别地在特定的限制条件,编码计划根据被设计下面在不同层次代表房间中心,这被显示出。最后,由扩大计划当着常规二十面体的 20 三角形的面,二十面体的关上的表面上的多决定格子完美地被探讨,这被显示出。对比实验证明建议编码计划有理论严密和高编程效率的优点并且跨脸的邻近的房间寻找的效率是乘一个类似的计划的的 242.9。而且,建议复杂根值数字表示是为格子系统的一个理想的形式化的描述工具。此处介绍的研究想法能被用来为 DGGS 创造一个通用理论框架。 展开更多
关键词 子系统 六角形 代数学 编码 分离 数字系统 几何关系 二十面体
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