A novel compensation method for polygonized mesa structures on(100) silicon substrate

A theoretical compensation method for polygonized mesa structures on（100） silicon substrate during the anisotropic etching process has been developed,which contains four stages as follows：prepare the information of the etching condition;predict the structure＇s undercutting profile;construct the topological structure of compensation patterns; and generate practical compensation patterns from the topological structure.The reasoning process is clearly stated,and detailed steps for the undercutting prediction and topological structure construction are summarized.Conclusions are also drawn about the rules which must be obeyed during the pattern generation process.The simulation and experimental results of some polygon structures are finally given to prove this method＇s validity and reliability.

On the Polygonal Wear Evolution of Heavy-Haul Locomotive Wheels due to Wheel/Rail Flexibility and Its Mitigation Measures

Wheel polygonal wear can immensely worsen wheel/rail interactions and vibration performances of the train and track,and ultimately,lead to the shortening of service life of railway components.At present,wheel/rail medium-or high-frequency frictional interactions are perceived as an essential reason of the high-order polygonal wear of railway wheels,which are potentially resulted by the flexible deformations of the train/track system or other external excitations.In this work,the effect of wheel/rail flexibility on polygonal wear evolution of heavy-haul locomotive wheels is explored with aid of the long-term wheel polygonal wear evolution simulations,in which different flexible modeling of the heavy-haul wheel/rail coupled system is implemented.Further,the mitigation measures for the polygonal wear of heavy-haul locomotive wheels are discussed.The results point out that the evolution of polygonal wear of heavy-haul locomotive wheels can be veritably simulated with consideration of the flexible effect of both wheelset and rails.Execution of mixed-line operation of heavy-haul trains and application of multicut wheel re-profiling can effectively reduce the development of wheel polygonal wear.This research can provide a deep-going understanding of polygonal wear evolution mechanism of heavy-haul locomotive wheels and its mitigation measures.

Entanglement polygon inequalities for a class of mixed states

The study on the entanglement polygon inequality of multipartite systems has attracted much attention.However,most of the results are on pure states.Here we consider the property for a class of mixed states,which are the reduced density matrices of generalizedW-class states in multipartite higher dimensional systems.First we show the class of mixed states satisfies the entanglement polygon inequalities in terms of Tsallis-q entanglement,then we propose a class of tighter inequalities for mixed states in terms of Tsallis-q entanglement.At last,we get an inequality for the mixed states,which can be regarded as a relation for bipartite entanglement.

Measured dynamic load distribution within the in situ axlebox bearing of high-speed trains under polygonal wheel–rail excitation

The dynamic load distribution within in-service axlebox bearings of high-speed trains is crucial for the fatigue reliability assessment and forward design of axlebox bearings. This paper presents an in situ measurement of the dynamic load distribution in the four rows of two axlebox bearings on a bogie wheelset of a high-speed train under polygonal wheel–rail excitation. The measurement employed an improved strain-based method to measure the dynamic radial load distribution of roller bearings. The four rows of two axlebox bearings on a wheelset exhibited different ranges of loaded zones and different means of distributed loads. Besides, the mean value and standard deviation of measured roller–raceway contact loads showed non-monotonic variations with the frequency of wheel–rail excitation. The fatigue life of the four bearing rows under polygonal wheel–rail excitation was quantitatively predicted by compiling the measured roller–raceway contact load spectra of the most loaded position and considering the load spectra as input.

凸F-多边形内部的F-点数

An F-polygon is a simple polygon whose vertices are F-points, which are points of the set of vertices of a tiling of R~2 by regular triangles and regular hexagons of unit edge. Let f(v) denote the least possible number of F-points in the interior of a convex F-polygon K with v vertices. In this paper we prove that f(10) = 10, f(11) = 12,f(12) = 12.

Investigation on influencing factors of wheel polygonization of a plateau high-speed EMU train

Purpose–This study aims to investigate the cause of high-order wheel polygonization in a plateau high-speed electric multiple unit(EMU)train.Design/methodology/approach–A series of field tests were conducted to measure the vibration accelerations of the axle box and bogie when the wheels of the EMU train passed through tracks with normal rail roughness after re-profiling.Additionally,the dynamic characteristics of the track,wheelset and bogie were also measured.These measurements provided insights into the mechanisms that lead to wheel polygonization.Findings–The results of the field tests indicate that wheel polygonal wear in theEMUtrain primarily exhibits 14–16 and 25–27 harmonic orders.The passing frequencies of wheel polygonization were approximately 283–323 Hz and 505–545 Hz,which closely match the dominated frequencies of axle box and bogie vibrations.These findings suggest that the fixed-frequency vibrations originate from the natural modes of the wheelset and bogie,which can be excited by wheel/rail irregularities.Originality/value–The study provides novel insights into the mechanisms of high-order wheel polygonization in plateau high-speed EMU trains.Futher,the results indicate that operating the EMU train on mixed lines at variable speeds could potentially mitigate high-order polygonal wear,providing practical value for improving the safety,performance and maintenance efficiency of high-speed EMU trains.

基于Polygon-Nurbs混合建模的汽车造型数字化设计

文章阐述了汽车造型数字化设计中Polygon建模与Nurbs建模的特点与适用情境。提出了一种基于Polygon-Nurbs混合建模的汽车造型数字化设计方法。该建模方法的核心流程是先采用多边形确定形体,再使用Nurbs建模构建稳定的曲面。基于该混合建模思路,进行了汽车造型设计实践,证明了该建模方法能够发挥两种建模方式的优点,快速准确构建形体,并能生成高质量的曲面模型。

Effect of surface microstructure of aluminum coating on corrosion properties of magnetic refrigerant gadolinium

AI coatings with different microstructures were prepared on the surface of Gd using the magnetron sputtering technique to improve its corrosion resistance. The corrosion behaviors for the pure Gd and Gd with Al coating in distilled water were studied using the mass loss and electrochemical performance. As a result, pure Gd without coating shows a certain amount of surface cracks under water flow conditions, whereas the polygonal Al coating decreases the path of the corrosive medium to body due to the existence of eroding pits structure. Compared with the polygonal structure Al coating and pure Gd, the lamellar structure of Al coating exhibits a higher electrochemical protection performance （e.g., a lower corrosion current and higher self-corrosion potential） and no occurrence of pitting corrosion. Due to an effective physical shield, the formation of the lamellar structure protected the inner Gd part from being corroded, and prolonged the duration of cathodic protection.

An Algorithm for Partitioning Polygons into Convex Parts

An algorithm for partitioning arbitrary simple polygons into a number of convex parts was presented. The concave vertices were determined first, and then they were moved by using the method connecting the concave vertices with the vertices of falling into its region B,so that the primary polygon could be partitioned into two subpolygons. Finally, this method was applied recursively to the subpolygons until all the concave vertices were removed. This algorithm partitions the polygon into O(l) convex parts, its time complexity is max(O(n),O(l 2)) multiplications, where n is the number of vertices of the polygon and l is the number of the concave vertices.

基于Polygon的雕塑法计算机辅助造型设计方法

计算机辅助设计技术已成为设计表现的必备手段,对于概念造型设计而言,接近传统手工方式的设计方法更易于被艺术设计师理解和接受。在对比目前主要计算机辅助造型方法的基础上,从分析传统手工雕塑造型的方式出发,针对概念设计和艺术造型设计的实际特征,提出了基于Polygon建模的雕塑法建模思路,给出了具体的建模步骤和合理布线的评价方法,并通过民间工艺品-泥塑马的造型实现过程进行了实例验证。实际运用证明,计算机雕塑建模方法对于艺术设计的三维软件建模理念具有较强的实用性,能够充分按照设计师的构思理念进行造型设计,对于创意设计而言更易于被造型设计师理解和运用。

一种实用的点/多面体分类算法

本文基于多面体表面的局部特性,提出了一种新的点/多面体分类算法,该算法适合于用边界表示法表示的任意多面体,可靠性高,具有很强的实用性。

新时代下三维动画专业基础课程设计的探索

目前许多高等院校都开设有三维动画专业,根据应用类型的不同涉及到如3DMax、Maya、Cinema4D等软件。同时,该专业的基础课程都会涉及到建模。三维模型的建模方式有很多种,从Polygon中的基本体扩展到平面图形的三维转换,从Nurbs中的编辑点挤出放样到二者之间的相互转换等。无论是哪一种方法,从布线结构的角度来看都遵守了一定的规律。笔者在多年任教过程中总结了一套关于三维动画基础课程的教学方法,通过具体分析一个模型的不同布线结构出发,来讨论什么样的布线才是最合适模型的。同时,通过分析当下游戏动画行业对模型制作的要求以及未来的发展趋势,衍生出笔者对如何教好三维动画专业课的一点思考。

Design and analysis of modular charge feeding mechanism

Aiming at the turning motion＇s disadvantages,including the instability of charge magazine caused by polygon effect and the disability of synchronously pushing modular charge of the current pushing mechanism,a new type of charge feeding mechanism is designed.It can not only select modular charge rapidly and steadily,but also push a certain amount of modular charge into the tray which is used to receive the charge synchronously.The selection and push principles of feeding mechanism are introduced,and a three-dimensional model is established.ADAMS is applied to simulation analysis of the feeding mechanism.The results show that the feeding mechanism can push the modular charge into the reception tray rapidly and steadily,which provides a theoretical basis for the practical design.

基于地铁轨道交通环控系统的虚拟现实与仿真关键技术研究

本文以地铁轨道交通环控系统项目为例,对虚拟现实与仿真关键技术进行了开发流程论述:提出了符合虚拟现实与仿真项目的模型制作规范;分别介绍了3ds Max和Unfold3D软件制作UV的技巧;针对纹理贴图详细阐述了AO贴图与高真实感的PBR材质制作流程;最后论述了UGUI控件、Unity3D功能组件以及C#脚本语言在地铁轨道交通环控系统项目开发中的作用。本文的研究对于虚拟现实与仿真项目的开发具有较好的理论指导和实际操作借鉴意义。

实事求是选择三维建模方法探讨

随着计算机技术的飞速发展,三维动画也随之越来越广泛,制作速度就显得非常重要。本文就建模这一模块来阐述如何实事求是地选择建模方法来提高建模速度。

基于多媒体技术的3D建模方法与实践

3D建模就是利用三维制作软件通过虚拟三维空间构建出具有三维数据的模型。本文基于Maya软件研究了多媒体中多种3D建模,通过NURBS建模与多边形建模的实际模型的制作研究了3D建模的制作方法。

ON THE GROWTH OF ZERO ORDER LAPLACE-STIELTJES TRANSFORM CONVERGENT IN THE RIGHT HALF-PLANE

In this article, authors study the growth of Laplace-Stieltjes transform with zero order convergent in the right half-plane, define the exponential order and the exponential low order, and find the relations between them. Some results similar to Dirichlet series are obtained.

三维动画建模技术的应用研究探析

建模是三维动画设计制作的第一步,是三维世界的核心和基础,没有一个好的模型,其他什么好的效果都难以表现,3DMAX具有多种建模手段。除了内置的几何体模型和对图形的挤压、车削、放样建模以及复合物体等基础建模外,目前最流行的3D建模方法主要有多边形建模、非均匀有理B样条曲线建模(NURBS)、细分曲面技术建模。本文结合三维动画中物体的分类,具体探讨了当前三维动画中3D建模技术的应用研究。

Prediction and Control of Wrinkle and Fracture for Stamping Regular Polygonal Box

Based on the deformation characteristic of regular polygonal box stamped parts and the superfluous triangle material wrinkle model,the criterion of regular polygonal box stamped parts without wrinkle was deduced and used to predict and control the wrinkle limit.According to the fracture model,the criterion of regular polygonal box stamped parts without fracture was deduced and used to predict and control the fracture limit.Combining the criterion for stamping without wrinkle with that without fracture,the stamping criterion of regular polygonal box stamped parts was obtained to predict and control the stamping limit.Taken the stainless steel0Cr18Ni9(SUS304)sheet and the square box stamped part as examples,the limit diagram was given to predict and control the wrinkle,fracture and stamping limits.It is suitable for the deep drawing without flange,the deep drawing and stretching combined forming with flange and the rigid punch stretching of plane blank.The limit deep-drawing coefficient and the minimum deep-drawing coefficient can be determined,and the appropriate BHF(blank holder force)and the deep-drawing force can be chosen.These provide a reference for the technology planning,the die and mold design and the equipment determination,and a new criterion evaluating sheet stamping formability,which predicts and controls the stamping process,can be applied to the deep drawing under constant or variable BHF conditions.

The Optimization Method of the Sector Partition Based on Metamorphic Voronoi Polygon

Voronoi diagram is founded by using computational geometry based on originaldistribution of the waypoints, and then the elements from Voronoi diagram are metamorphosed by usingthe rule for airsppce partition, and the controller's workload is accounted in each element that ismade up of Metamorphic Voronoi polygon. Then in accordance with the rule about balance ofcontroller's workload, Simulated Annealing algorithm (SA) is used to achieve the optimization ofcombination of those elements , and the new resolution has satisfied the restriction of two rulesfor airspace partition. Therefore, the boundaries of the aggregates of these elements are theoptimal borderlines of sectors. The result of actual airspace design example validates therationality of the sector optimization method presented in this paper.