Three-Dimensional Prototypes and Evaluation of Their Structure and Form

In order to reveal the appearance of the clothing prototype on the human body,the characteristics of the human body’s structure above the waist section were studied.Based on the experimental data of the fit prototype,three-dimensional prototypes features were comparatively analyzed.And then objectively evaluating the relationship was conducted between the planar structure lines of different prototypes and the human body.The results showed that the prototypes analyzed basically conformed to the size of the human body.However,when they were worn on the human body,there were problems in the structure and forming.The main reason was that the side seam was skewed to different degrees.The results of this study provide reference for many practitioners to choose prototypes.

A CLOSED FORM SOLUTION OF STRESS INTENSITY FACTORS FOR THREE DIMENSIONAL FINITE BODIES WITH ECCENTRIC CRACKS

In this paper, a new analytical-engineering method of closed form solution about stress intensity factors for three dimensional finite bodies with eccentric cracks is derived by means of energy release rate method. The results of stress intensity factors can be obtained. The results provided ir this method are in nice agreement with those of the famous alternating method by which only special cases can be solved.

A more general form of lump solution,lumpoff,and instanton/rogue wave solutions of a reduced (3+1)-dimensional nonlinear evolution equation

In this manuscript,a reduced(3+1)-dimensional nonlinear evolution equation is studied.We first construct the bilinear formalism of the equation by using the binary Bell polynomials theory,then explore a lump solution to the special case for z=x.Furthermore,a more general form of lump solution of the equation is found which possesses seven arbitrary parameters and four constraint conditions.By cutting the lump by the induced soliton(s),lumpoff and instanton/rogue wave solutions are also constructed by the more general form of lump solution.

Quantifying.Associations among Dimensions of Ears and Their Form Factors in Maize(Zea Mays)Using Dimensional Analysis

Ear morphological traits such as volume and shape are important features of maize and the quantitative associations among them can help understand kernel yield determination. 150 mature ears each of 4 maize cultivars were collected from field experiments, and ear length(L), diameter(D), area(S) and volume(V) were recorded for individual ears, kernel weight per ear also recorded for a portion of the examined ears. Following principles of dimensional analysis, 8 theoretical equations of 3 sets,which relate ear higher dimensions to its length and diameter, were developed and parameterized and validated with the field observations. The 3 optimized equations showed that the shape of ears in maize can be featured with 3 dimensionless form factors, namely diameter-to-length ratio(c=D/L), areal form factor(b=S/L/D), and volumetric form factor(a=V/L/D/D). Statistically,all of them were significantly different among cultivars, and a's values varied from 0.582 to 0.612, and b's 0.839-0.868, and c's 0.242-0.308. Volumetric form factor and areal form factor could estimate precisely ear volume and area respectively, but diameter-to-length ratio was not suitable to estimate ear diameter by its length. Ear volume explained almost all variation of ear kernel weight and product L*D*D did the same substantially. Dimensional analysis proved to be promising in understanding relationship among morphological traits of ears in maize. Its application in crop researches should improve our knowledge of the physical properties of crop plants.

基于FreeForm与3ds Max建模的三维打印

针对三维打印机对产品设计与制作周期的要求较高,传统的专业建模软件对于普通大众来说可实现性较差,不利于推广三维打印技术的问题,对比了传统建模软件与Free Form触觉建模系统的建模特点,提出了一种将Free Form系统和3ds Max软件相结合的建模方式。首先,在Free Form系统中设计具有自由曲面特性的基本黏土模型,并将设计完的模型按比例缩减10%后以STL格式导出;其次,将模型导入到3ds Max软件中,利用复合建模方法继续对模型进行外观设计和尺寸处理;最后,将模型重新加载到Free Form系统中进行模型修复和细节加工,输出经过近似处理的STL格式的三维模型。实验结果表明,该建模方法相对于传统专业建模软件下的建模,提高了建模速度,缩短了产品制作周期,建立的模型经Maker Bot Desktop软件切片处理后,可成功地转化为x3g格式的打印模型,并能在三维打印机上正确打印。

Closed form solution of stress intensity factors for cracks emanating from surface semi-spherical cavity in finite body with energy release rate method

In this paper, a new semi-analytical and semi-engineering method of the closed form solution of stress intensity factors （SIFs） of cracks emanating from a surface semi-spherical cavity in a finite body is derived using the energy release rate theory. A mode of crack opening displacements of a normal slice is established, and the normal slice relevant functions are introduced. The proposed method is both effective and accurate for the problem of three-dimensional cracks emanating from a surface cavity. A series of useful results of SIFs are obtained.

Lump-type solutions of a generalized Kadomtsev–Petviashvili equation in(3+1)-dimensions

Through the Hirota bilinear formulation and the symbolic computation software Maple, we construct lump-type solutions for a generalized(3+1)-dimensional Kadomtsev-Petviashvili(KP) equation in three cases of the coefficients in the equation. Then the sufficient and necessary conditions to guarantee the analyticity of the resulting lump-type solutions(or the positivity of the corresponding quadratic solutions to the associated bilinear equation) are discussed. To illustrate the generality of the obtained solutions, two concrete lump-type solutions are explicitly presented, and to analyze the dynamic behaviors of the solutions specifically, the three-dimensional plots and contour profiles of these two lump-type solutions with particular choices of the involved free parameters are well displayed.

The Properties of an UV Curable Support Material Pre-polymer for Three Dimensional Printing

An ultraviolet（UV） curable support material pre-polymer for three dimensional printing was prepared based on the synergistic effect between PEO-PPO-PEO tri-block copolymer（F127） and polyethylene glycol （400） di-acrylate（SR344）. The effects of jetting conditions, thermal stability, curing time, mechanical properties and shrinking rate on printing models were studied. The situation of removing support material from build model was investigated after building progress was completed. The experimental result shows that when F127 is 6.0wt%, SR344 is 20.0wt%, 4-Methoxy phenol is 0.15wt% and Irgacure 2959 is 1.5wt%, the support material pre-polymer could be jetted out from the nozzles smoothly during building up of three dimensional printing models at 50-55 ℃. In addition, the support material could be removed easily from building model without spoiling the model; furthermore, the forming precision of building model is improved.

Diversity of Interaction Solutions to the (2 + 1)-Dimensional Sawada-Kotera Equation

In this paper, based on Hirota bilinear form, we aim to show the diversity of interaction solutions to the (2 + 1)-dimensional Sawada-Kotera (SK) equation. By introducing an arbitrary differentiable function in assumption form, we can obtain abundant interaction solutions which can provide the possibility for exploring the interactions between lump waves and other kinds of waves. By choosing some particular functions and values of the involved parameters, we give four illustrative examples of the resulting solutions, and explore some novel interaction behaviors in (2 + 1)-dimensional SK equation.

城市建筑立体复合形态演变及机制——以巴黎为例

选取3个不同时期具有立体复合特征的巴黎城市项目为样本,呈现了从集权式的大尺度整体建设逐渐转向多元主体掌控的精细化、小颗粒度协作开发的形态演变进程;通过形态与价值观念和政策制度的关联分析,揭示了其内在成因机制;从建筑三维形体、功能立体布局、建筑与城市渗透性、建筑高度、公共空间品质等方面出发,总结了巴黎城市以立体复合利用为特征的精细化管控体系与方法.最后,通过对3个项目的回溯与总结,提出目标、制度、策略的协同共进是实现城市建筑立体复合形态的重要基础,并对我国城市规划设计及管控提出了建立多元主体协商机制、采用三维形态管控方法、构建城市与建筑一体化管控指标、明确总师责权的建议.

紫云英长期还田对稻田土壤DOM和Cd形态影响研究

长期种植和翻压紫云英能够显著提高土壤中有机质(SOM)和水溶性有机物(DOM)的含量,影响土壤颗粒对重金属镉(Cd)的吸附行为和Cd在土壤中的形态,了解该条件下Cd在不同土层中的特征对紫云英的进一步推广种植具有重要意义。以余江区(YJ)、南昌县(NC)、丰城市(FC)3地长期种植和翻压紫云英处理(F+M)和化肥处理(F)的定位试验点为研究对象,测试了不同层次土壤中SOM、水溶性有机碳(DOC)含量、Cd总量和形态、DOM三维荧光,以期探明紫云英长期还田模式下不同土层中DOM成分的差异及其对Cd含量和形态影响。结果显示,NC和FC试验点F+M处理耕作层土壤(0-20 cm)中SOM的含量显著高于F处理,分别提高16.8%和10.5%。同一土层中土壤Cd活性呈现F+M处理>F处理的趋势。紫云英DOM主要在耕作层和中层(20-40cm)土壤中迁移,YJ、NC、FC试验点中,F+M处理耕作层土壤中DOC含量比F处理分别提高17.0%、58.1%和33.7%,中层土壤中DOC含量分别提高43.0%、36.7%和11.2%。种植和翻压紫云英降低了DOM中类蛋白质组分的占比,增加了类腐殖质组分的占比,耕作层、中层和深层土壤(40-60 cm)中,3个试验点F处理DOM中类蛋白质的平均占比分别为7.34%、16.7%、23.9%,占比分别是F+M处理的1.26、1.92和1.54倍。类蛋白质组分的深层迁移能力大于类腐殖质组分。逐步回归分析表明,有生物活性的Cd形态占比与土壤SOM、类色氨酸含量存在负相关关系,与类富里酸含量存在正相关关系,其系数分别为-2.170、-0.760和0.239。常年种植和翻压紫云英通过影响土壤SOM总量以及DOM组分对土壤Cd表现出一定的活化潜力。

Lump and interaction solutions to the (3+1)-dimensional Burgers equation

The(3+1)-dimensional Burgers equation, which describes nonlinear waves in turbulence and the interface dynamics,is considered. Two types of semi-rational solutions, namely, the lump–kink solution and the lump–two kinks solution, are constructed from the quadratic function ansatz. Some interesting features of interactions between lumps and other solitons are revealed analytically and shown graphically, such as fusion and fission processes.

现代立体漆艺创作的表现形式与审美特性

漆艺艺术也称大漆艺术,是我国最为古老的传统艺术形式之一,早在春秋战国时期便已出现。最早大漆艺术多以工具性特征为主,凭借漆的防腐、耐酸等特性被广泛用于涂饰工艺,随着时代的变迁,越来越多的新材料被运用到大漆艺术中,大漆艺术也渐渐由工艺而进化成了一门具有别样美感的艺术形式。随着更多新材料和新工艺的出现,现代大漆艺术已完全蜕变成为一种独立的艺术形式,其中最具代表性的当属当代的立体漆艺艺术。以现代立体漆艺为研究对象,分析现代立体漆艺创作的造型思路和装饰技法,探讨现代立体漆艺创作的表现形式和审美特征。

轻合金矩形管件充液压制成形缺陷及横截面尺寸控制

管材充液压制是一种先进的低载荷液压成形工艺,可用于整体成形复杂薄壁管状构件。与内高压成形不同,充液压制过程中内压只起支撑作用避免失稳屈曲,主要通过模具压制获得管件外形轮廓。压制过程管坯厚向存在拉-压应力梯度,导致卸载后管件截面易产生回弹,影响尺寸精度。本研究通过对5052、AZ31B和TA1三种管材进行充液压制成形实验,分析了支撑内压和环向压缩率对矩形管件横截面尺寸的影响规律。结果表明:当支撑内压为0.6p_(s)~0.8p_(s)时,管件截面的回弹最小,此时最大回弹量小于1.5 mm,对应回弹率小于5.2%,上、下圆角半径相差小于0.1 mm。通过控制环向压缩率可减小管件回弹,截面尺寸与设计尺寸相差小于0.2 mm,尺寸偏差小于0.7%。对于5052-H、5052-O、AZ31B-M和TA1-Y矩形管件,其控制尺寸精度所需的环向临界压缩率分别为1.8%、1.7%、1.9%和1.8%。

面料性能对A字裙坐姿起皱形态的影响

着装褶皱对服装外观有重要影响,常见的褶皱评价指标及传统的二维图像处理技术无法准确、全面反映三维起褶状态。因此,文章利用三维扫描技术对坐姿下A字裙形成的褶皱从褶皱区域、褶皱类型、褶皱大小和褶皱尖锐度四方面建立了一系列新指标,运用单因素方差分析比较了不同种类面料间的褶皱形态差异,并探究了面料性能与褶皱形态指标之间的相关性。研究结果表明,不同面料成分的A字裙在坐姿下形成的褶皱形态各异,其中棉类与其他面料之间各方面差异最为明显。此外,经密、抗弯刚度、褶皱回复性等面料性能对褶皱形态各指标有着不同程度的影响。研究结果可为面料选择及服装三维仿真提供参考。

基于光Blass矩阵的光控二维多波束产生

多波束是电子信息装备实现多功能、多任务、大容量信息传输与处理的关键。围绕新一代相控阵系统对宽带多波束形成网络的应用需求,提出一种基于光Blass矩阵的两级级联结构产生二维多波束的实现方法。通过光域相干波束形成技术完成第一级水平方向的波束合成,再利用光域非相干波束形成技术实现第二级垂直方向的波束合成,进而获得空域二维波束。采用该架构,一方面可突破光波长数量不足对光控波束形成网络阵列规模的限制,可将光控相控阵系统的单元规模从数十个提升至数百个甚至更多;另一方面可大幅减少光控多波束芯片的数量,对于阵元数N×N、波束数量M×M的多波束系统,波束芯片数量可从M^(2)个减少到(N+M)个。同时该方案可采用光子集成技术手段实现,在简化多波束系统结构与提升系统可靠性方面具有无可比拟的优势。

多维曲面成形运动规划中三维模型数据处理研究

多维曲面成形过程中三维模型读取和空间目标点的求解效率对提高成形速度具有重要影响作用。随着STL模型复杂度提升,三角面片数量相应增加,计算复杂度大幅增长,求解效率降低,运动规划和图案映射过程计算难度也随之增加。针对上述问题基于深度学习方法提出一种三维模型数据处理及运动规划方法,并与传统的计算规划方法进行对比。实验结果表明,所提方法能有效提升曲面打印中模型数据点定位速度2倍以上,定位速度随求解点数据量增加而提升,且对模型顶点数增加具有鲁棒性,大大提升运动规划速度,为多维曲面成形运动规划求解提供新思路,适用于大规模数据计算且可被用于直接交互现实的生产制造任务。

基于多源数据的城市形态与功能业态耦合分析——以乌鲁木齐市中心区为例

城市中心区的各功能业态聚集与分散是城市空间形态演变的重要结果,其合理布局对城市中心区的发展至关重要.基于高精度的中心区三维空间数据及城市兴趣点(POI)功能业态数据,以乌鲁木齐市中心区为研究对象,选取空间强度、密度、高度作为空间形态的测度指标,结合双变量空间自相关解析城市中心区空间形态与不同功能业态分布的空间耦合性特征,并通过空间计量模型对比进行实证分析.结果表明:中心区在空间形态呈现由中心至外围逐渐递减的分布趋势;四个功能业态分布集中在大小西门商圈;通过GMI方法分析得出居住型功能区与空间强度、空间密度和空间高度的耦合相关性最大,其次是生产型功能区;通过遴选得出高显著相关性地块和低显著相关性的“问题”地块中存在问题,为未来城市更新提供一定参考意义.

大型厚板曲面件的多点成形仿真

传统的厚板曲面件制造方法存在着成本高、效率低等问题,多点成形技术为这一问题提供了解决方法。但多点成形技术又因为回弹导致工艺参数难以确定使实验操作次数增加,降低成形效率。为了提高成形效率,采用ABAQUS有限元软件模拟与实验相结合的方法进行板料成形的研究与分析。首先,利用有限元软件进行三维建模并模拟板料的成形过程;然后,通过对模拟结果的分析进行模具型面的补偿修正;最后,利用修正后的模具型面进行实验操作,获得了符合要求的零件。对修正后的型面进行成形实验可以减少操作次数,提高实验的成形效率,为后续的研究提供参考。

一种弹簧原长几何尺寸误差检测与补偿方法研究及其设备实现

弹簧成型机制造的弹簧存在尺寸偏差问题,针对弹簧原长几何误差问题设计了一种简易的检测与补偿机构,利用弹簧的金属特性使其逐个通过标准长度的检测槽排,利用接通导电原理检测几何长度,通过PLC实现自动控制检测。实测结果表明,本装置具有检测原理简单、结构稳定、运行稳定和效率高效的特点,提高了产品质量与劳动效率。