一种3D Octagon双环片上网络拓扑结构

随着片上网络IP核结点的增加,芯片面积受限的问题日益突出,利用3D拓扑,用体积换取芯片面积是一种可行的方案,这种结构使各个结点的物理距离更近,从而充分地利用了空间资源,可以有效地减少芯片面积。提出一种3D Octagon双环拓扑结构,在均衡负载模式和对称随机负载模式下分析了其网络延迟和吞吐率。结果表明,3D Octagon双环是一种性能良好、可行性高的片上网络拓扑结构。

Numerical simulation of the hydrodynamics within octagonal tanks in recirculating aquaculture systems

A three-dimensional numerical model was established to simulate the hydrodynamics within an octagonal tank of a recirculating aquaculture system. The realizable k-e turbulence model was applied to describe the flow, the discrete phase model （DPM） was applied to generate particle trajectories, and the governing equations are solved using the finite volume method. To validate this model, the numerical results were compared with data obtained from a full-scale physical model. The results show that： （1） the realizable k-e model applied for turbulence modeling describes well the flow pattern in octagonal tanks, giving an average relative error of velocities between simulated and measured values of 18% from contour maps of velocity magnitudes; （2） the DPM was applied to obtain particle trajectories and to simulate the rate of particle removal from the tank. The average relative error of the removal rates between simulated and measured values was 11%. The DPM can be used to assess the self-cleaning capability of an octagonal tank; （3） a comprehensive account of the hydrodynamics within an octagonal tank can be assessed from simulations. The velocity distribution was uniform with an average velocity of 15 cm/s; the velocity reached 0.8 m/s near the inlet pipe, which can result in energy losses and cause wall abrasion; the velocity in tank corners was more than 15 cm/s, which suggests good water mixing, and there was no particle sedimentation. The percentage of particle removal for octagonal tanks was 90% with the exception of a little accumulation of 〈5 mm particle in the area between the inlet pipe and the wall. This study demonstrated a consistent numerical model of the hydrodynamics within octagonal tanks that can be further used in their design and optimization as well as promote the wide use of computational fluid dynamics in aquaculture engineering.

Effect of interaction and temperature on quantum phase transition in anisotropic square-octagon lattice

We investigate the effect of interaction, temperature, and anisotropic parameter on the quantum phase transitions in an anisotropic square-octagon lattice with fermions under the framework of the single band Hubbard model through using the combination of cellular dynamical mean field theory and a continuous time Monte Carlo algorithm. The competition between interaction and temperature shows that with the increase of the anisotropic parameter, the critical on-site repulsive interaction for the metal-insulator transition increases for fixed temperature. The interaction-anisotropic parameter phase diagram reveals that with the decrease of temperature, the critical anisotropic parameter for the Mott transition will increase for fixed interaction cases.

Mobility Issue on Octagonal Structured ZigBee Network Using Riverbed

Wireless Sensor Network (WSN) is a special type of communication medium through distributed sensor nodes. Popular wireless sensor nodes like ZigBee have splendid interoperability after IEEE 802.15.4 standardization in the domain of wireless personal area network (WPAN). ZigBee has another great feature mobility that makes the ZigBee network more versatile. The mobility feature of ZigBee mobile nodes has a greater impact on network performance than fixed nodes. This impact sometimes turns into more severe because of network structure and mobility model. This study mainly focuses on the performance analysis of the ZigBee mobile node under Random and Octagonal mobility management model with the Tree routing method. The Riverbed academic modeler is used to design, implement and simulate the ZigBee network under certain conditions. This study also presents a competitive performance analysis based on ZigBee mobile nodes transmitter and receiver characteristics under the observation of the mobility model. This indicates that Octagonal mobility model exhibits better performance than the Random mobility model. This study will constitute a new way for further designing and planning a reliable and efficient ZigBee network.

Investigation of Heave Response of the Deepwater Octagonal FDPSO Using Various Heave Plate Configurations

Heave plates can be employed to control undesirable heave motion amplitudes of the deepwater octagonal Floating, Drilling, Production, Storage, and Offloading(FDPSO) platform. Numerical simulations and model tests were applied to analyze and investigate the hydrodynamic response and the feasibility of the heave plate configurations. The diameter and the depth below the free surface of a single-layer heave plate, as well as the spacing of two-layer heave plates, were considered as the primary variables when studying the effect of heave plates on FDPSO hydrodynamics. The analysis results indicate that the heave plate diameter significantly affects the heave hydrodynamics, and heave performance could be improved with an increased diameter. In addition, increasing the depth below the free surface of a single-layer heave plate does not effectively suppress the heave motion within the range of draft depths tested. The target FDPSO obtained better heave characteristics with increased spacing between the two-layer heave plates. Furthermore, the global performances of the octagonal FDPSO with these typical heave plate configurations were comparatively analyzed. The results indicate that from a hydrodynamic point of view, the single-layer heave plate configuration has an advantage over the two-layer heave plate configuration.

A MODE Ⅱ CRACK IN A TWO-DIMENSIONAL OCTAGONAL QUASICRYSTALS

The present study develops the fracture theory for a two-dimensional octagonal quasicrystals. The exact analytic solution of a Mode Ⅱ Griffith crack in the material was obtained by using the Fourier transform and dual integral equations theory, then the displacement and stress fields, stress intensity factor and strain energy release rate were determined, the physical sense of the results relative to phason and the difference between mechanical behaviors of the crack problem in crystal and quasicrystal were figured out. These provide important information for studying the deformation and fracture of the new solid phase.

Self-Similar Transformation and Vertex Configurations of the Octagonal Ammann-Beenker Tiling

Based on the matching rules for squares and rhombuses,we study the self-similar transformation and the vertex configurations of the Ammann-Beenker tiling.The structural properties of the configurations and their relations during the self-similar transformation are obtained.Our results reveal the distribution correlations of the configurations,which provide an intuitive understanding of the octagonal quasi-periodic structure and also give implications for growing perfect quasi-periodic tiling according to the local rules.

Square-octagon晶格中的量子自旋霍尔效应

从晶格的紧束缚近似哈密顿量出发,计算square-octagon晶格纳米带的能带结构,分析其边界态特点,并通过Fukui-Hatsugai方法进一步验证系统的拓扑性。计算表明,在合适的参数下,Rahsba自旋轨道耦合作用能产生一对无能隙螺旋边界态,且该边界态受到时间反演对称性保护。同时,在半个布里渊区内的整数场之和为奇数,表明系统处于量子自旋霍尔态。

Pathological unit and the octagonal en bloc resection of thoracic ossification ligamentum flavum

Objective To describe the pathological unit and octagonal en bloc resection for the treatment of ossification ligamentum flavum(OLF)in thoracic spine with spondylotic myelopathy.Methods Ninety-five patients from January 2002 to January

西南少数民族八角纹设计文化基因“数字化”表达与传递机理研究

八角纹在西南各少数民族染织纹样中的传递已有几千年的历史。类比生物基因“数字对位传递”所具有的高度精确性,如果对染织纹样中的八角纹进行“显微镜式的观察”,可以发现,八角纹隐含着“几何式”与“模件式”两种设计文化基因。其产生与复制的过程,是按照均衡比例的“数字化”机理进行表达与传递;指令信息的明确,使得传递后的设计文化基因具有高度的保真性、多产性与长寿性。本文研究表明,在西南少数民族八角纹等纹样的设计与制作过程中,传递“如何制作”(机理)比传递“制作什么”(纹样)更具有效性。

八角型螺栓球节点研发、配件标准编制和工程应用

高强度螺栓的“假拧”是螺栓球节点空间网格结构普遍存在的安全隐患及事故诱因之一。为此,提出一种空间网格结构用八角型螺栓球节点,并对其进行系统研发。介绍了该节点的组成、安装机理和主要优点。基于对该节点的研发成果,编制发布了其关键配件的产品标准——《螺栓球节点用八角型高强度螺栓和套筒》(T/CSCS011—2021),对该标准的主要编制思路和要点进行了介绍。最后介绍了该节点在珠海机场二号航站楼指廊屋盖网架中的应用情况,对采用该节点的网架和采用焊接球节点的网架进行了对比分析,结果表明,两种节点形式网架的力学性能和设计指标基本相当,八角型螺栓球节点网架的经济性更好。上述标准和节点的首次工程应用为该节点的推广奠定了良好基础。

基于中国古代纺织工具上的“八角星纹”研究

“八角星纹”是新石器时代出土文物上刻画较为典型的一种符号。为了探索纺织服装领域里遗存的“八角星纹”流变轨迹与文化内涵,解开“八角星纹”的历史发展脉络,文章采用了广泛收集博物馆出土带有“八角星纹”的出土纺轮、纺织机械、刺绣纺织品等文物,结合比较了其他领域出土带有“八角星纹”文物,梳理并通过图像分析了“八角星纹”传导于纺织领域的本真内涵。研究发现,“八角星纹”在中国古代文化中有着悠久的历史。“八角星纹”是古人对自然的朴素认知,是对天地祭祀的符号,这种符号被传导到各种行业的器具中。古人将“八角星纹”装饰于纺机与服饰上同样是源于祭祀信仰的结果,研究认为“八角星纹”来自古人“燔柴”祭祀的物化符号;“八角星纹”流变后与中华传统文化里的河图洛书诞生有着莫大的关联,是阴阳八卦学说产生源头,是中华先民对阴阳数理的崇拜较早地渗透到纺织领域里的见证。

带椭圆孔有限大二维八次对称准晶问题的应力分析

首先,利用扩展的Stroh方法,研究含椭圆孔无限大八次对称二维准晶板的格林函数,得到边界元法求解含椭圆孔有限大八次对称二维准晶板所需的基本解。其次,利用加权余量法,建立边界积分方程,采用线性插值函数及高斯积分对含未知量的边界积分方程进行离散并重新组织离散格式,形成变量统一的线性方程组。最后,对椭圆孔的孔边应力进行数值求解,并将有限大板的数值结果与无限大板的解析解进行对比验证,说明边界元法的有效性。进一步分析在垂向拉伸作用下,板材的尺寸、孔口的大小及倾斜角度对孔边应力的影响。数值实例结果表明,随着椭圆孔尺寸的增加,孔边应力集中现象越明显。若长轴垂直拉伸方向,椭圆孔倾斜会减缓孔边应力集中程度。而裂纹尖端的应力强度因子随着裂纹的增长而增加。

潜水推流器作用下八边形养殖池的集污性能

为了探究潜水推流器作用下八边形养殖池内的污物聚集特点,本研究利用物理模型试验的方法,研究潜水推流器不同的布设角度θ、布设距离比d/a(中垂线模式:d1为推流器叶轮轴线中点与最近的池壁之间的距离,a1为八边形养殖池长边边长;对角线模式:d2为推流器叶轮轴线中点与最近的短边边长之间的距离,a2为八边形养殖池排污口与最近的短边边长之间的距离)、推流器数量n和布设模式对八边形养殖池内污物聚集的影响。试验利用高清相机记录养殖池内的污物分布情况,并使用MATLAB分析计算污物与池中心的距离。实验中通过比较不同工况下污物与池中心距离的最大值的大小,衡量养殖池集污性能的优劣。结果显示,潜水推流器的布设角度θ、布设距离比d/a、推流器数量n以及布设模式都影响池内污物聚集的效果。在本研究设置的布设距离比工况下,潜水推流器布设角度θ为45°时集污效果最优,而当布设角度θ大于70°时,随着布设角度增加,八边形养殖池周边出现集污死角,残饵及粪便距离排污口中心变远且饲料离散程度变大;在30°、40°、45°、50°工况下,污物聚集效果随布设距离比d/a的增大逐渐增强,当布设距离比为1/2时集污效果最好。养殖池集污性能随潜水推流器数量的增加而整体呈现增强的趋势,尤其是潜水推流器数量从1增加至2时,集污性能明显提升,但是持续增加后,集污性能不再有明显的提升。其余设置条件相同的情况下,对角线布设模式下的养殖池集污性能明显优于中垂线布设模式。研究表明,潜水推流器采取对角线模式,布设时不少于2个,布设角度θ为45°附近,此时八边形养殖池集污性能较优。研究结果可为八边形养殖池内潜水推流器的布设方式提供依据与指导。

金属八角垫泄漏率与螺栓预紧力的关系研究

为了探究金属八角垫密封系统泄漏率与螺栓预紧力的关系,研究了平行圆盘模型和Roth模型,分析了部分金属材料密封性能系数与布氏硬度的关系,以及密封面比压力与泄漏率、螺栓预紧力的关系,得到了八角垫密封系统泄漏率与螺栓预紧力之间的函数关系式。利用该关系式,可以预测金属八角垫密封系统达到相应密封度等级需要多大的螺栓预紧力。并且进行了仿真模拟计算,在一定程度上验证了理论计算公式的准确性。

用于微波热疗的小型化开缝微带贴片和金属腔复合天线

传统的治疗癌症方法往往会产生严重的副作用。作为一种微创、高效、低毒的绿色治疗方法,近年来微波热疗受到越来越多人的青睐。本研究的重点是设计和评估用于热疗的工作频率为2450 MHz的微型开缝贴片天线。天线贴片呈八角形,包含4个对称槽,以减小尺寸并改善定向辐射。天线与组织之间增加了一个开放式金属腔,以保持预设距离,防止贴片直接接触皮肤,实现更好的阻抗匹配,减少对周围区域的能量辐射。根据比吸收率(SAR)、穿透深度(PD)和有效场强(EFS)对天线的性能进行评估,加工制作了天线并在猪肉组织中进行了测试,测量结果与模拟结果非常吻合。

锂离子电池撞击测试方法及参数研究

高能量密度的锂离子电池在使用和运输中,碰撞难以避免,品质控制尤为重要。电池受物理撞击后可能有内短路,为检验成品电池综合品质,需在出厂前进行可靠性检测。介绍可靠性检测中,八角转鼓设备的方法及合理的参数设置。借助运动仿真模拟电池在转鼓中的撞击参数,收集测试后电池的数据,以判断品质是否达到六西格玛(6σ)的工程能力。

重型八角瓦楞纸箱的抗压强度及其预测模型研究

为研究重型八角瓦楞纸箱抗压强度影响因素的主次顺序及其函数关系,建立科学合理的抗压强度预测模型。选取复合瓦楞纸板边压强度、底边周长、高度和邻边比为影响因素,基于相似准则设计四因素三水平正交试验,使用SPSS和MATLAB进行试验数据处理和多元线性回归方程拟合,并根据实际设计案例加工试样进行验证。结果表明,八角箱抗压强度影响因素的主次顺序为边压强度>底边周长>邻边比>高度;试验数据验算误差和试验验证误差分别为11.6%和11.08%,预测模型的精度高于传统普通纸箱常用的计算公式。研究结果为解决八角箱产品的抗压强度预测、选材和结构参数设计提供科学依据。

加氢反应器法兰安装密封技术

加氢反应器是加氢装置的关键设备,其顶部法兰安装时的密封技术要求高、难度大。吸取某300万t/a柴油加氢装置加氢反应器首次开工时法兰密封泄漏及维修缺少充分技术准备的教训,从密封结构特点出发确定了泄漏类型为密封压紧面泄漏,从螺栓预紧力矩计算、法兰密封槽和螺栓及垫片检查修复、法兰槽研磨及配合精度检查、紧固等方面细化安装程序和要求,在同类型加氢反应器法兰密封过程中严格落实,取得了良好应用效果,积累了成功经验。