圆柱

In addition,discussion is undertaken for the 60 metre width double-layer barrel vault about the structural steel weight and cot affected in different grid size、rise/width ratio and different loads.It also includes the effect of wind loads on those of 100 metre width structure.The application in the roof of coal storage of barrel va

以60m跨度的双层圆柱面网壳结构为对象，研究了不同网格尺寸、不同矢跨比、不同荷载对结构的用钢量、造价等结果的影响；以及不同风荷载对100m跨度网壳计算结果的影响；比较分析了三心圆柱面网壳与圆柱面网壳结构在电厂干煤棚中的应用。

To assure parts' machining precision and to improve productivity, touch probe is used to inspect cylinder of parts on machining centers, thus coordinate of points on features are acquired from numerical control system by a data collecting program, and cylindricity error is calculated by computer. This method has broken the restriction of probe's macro processor that couldn't work out cylindricity error. Data saved in computer are beyond the limited memory of numerical control system, which improves operation speed.

为了保证零件加工精度和提高生产率，在数控加工中心中采用触发式零件检测测头对被加工件的圆柱面进行在机检测，并利用数据读取程序从数控系统内部提取被检测点坐标信息，在计算机内部完成圆柱度误差的计算，克服了零件检测测头自带宏程序无法对圆柱等被测特征进行误差运算的局限性；并且检测数据存储于计算机内，不再受数控系统内存小及运算速度慢的限制。

In addition, three-dimension scattering characteristics of aplane wave by a cylindrical conductor are described by applying reduced matrix.

应用平面波谱技术将高斯波束展开成平面波序列，然后利用叠加原理及圆柱导体的边界条件推导了基模高斯波束入射单个圆柱导体的二维散射场公式，应用约化矩阵描述了平面波入射单个圆柱导体的三维散射特性。

In the cylindrical worm pair with disk annular grinding wheel enveloped worm, the worm axial profile is concave profile.

圆弧面砂轮包络圆柱蜗杆传动，兼备了二次包络成形的特征和凹面齿圆柱蜗杆的特征，是一种很有特色的新型圆柱蜗杆传动。

A self-drilling anchor (10) for use in a friable material (1) comprises a body (12) having an axis (13), a flanged rear end (14), a drilling front end (16) and a generally cylindrical portion (18) therebetween having an outer surface (20) with a thread (22) disposed thereon, wherein the body forks, beginning at a predetermined distance from the flanged rear end, into a first leg (24) and a second leg (26), the first leg extending forwardly into a drilling tip (28) and having a generally rearward facing shoulder (30) angled obtusely outwardly with respect to the axis, wherein the body (12) has an axial bore (32) for receiving an elongate fastener (2), the axial bore (32) extending substantially through the flanged end (14) and the generally cylindrical portion (18) and leading to the generally rearward facing shoulder (30), wherein the anchor (10) has a drilling mode wherein the second leg (26) nests behind the generally rearward facing shoulder (30) of the first leg (24), and an anchoring mode wherein the legs are pivoted apart from one another.

一种用于易碎材料(1)中的自攻螺钉(10)，包括：主体(12)，其具有中心轴(13)、带有凸缘的后端部(14)、用于钻孔的前端部(16)和位于所述后端部和前端部之间的通常为圆柱状的部分(18)，所述圆柱状部分(18)的外表面(20)上布置有螺纹(22)，其中主体从距离带有凸缘的后端部的预定的距离处开始分叉为第一腿(24)和第二腿(26)，第一腿向前伸入钻孔尖端(28)，并且具有相对于中心轴向外成钝角的通常面向后的肩部(30)，主体(12)具有容纳细长状紧固件(2)的轴向孔(32)，轴向孔(32)基本延伸穿过带有凸缘的端部(14)和通常为圆柱状的部分(18)，并且通向通常面向后的肩部(30)，螺钉(10)具有钻孔状态和固定状态，在钻孔状态，第二腿(26)套在第一腿(24)的通常面向后的肩部(30)之后，并且在固定状态，腿彼此转动分离。

Feature parameters are achieved by comparing the coefficient of standard representation and general representation. As for cone, parameter of general representation has no explicit geometric meaning and can not reflect design intent.

基于二次曲面的统一表示方程，采用最小二乘法进行参数拟合，通过对比其标准形式和二次曲面的统一表示方程，确定圆柱曲面特征带有明显几何意义的参数圆柱轴线法矢量、圆柱的中心和半径。

The simulation results of the cylinder-block model were given in the article, consistent with that of Middlemen"s. It was shown that the block part could improve the uniformity of the flow distribution. The analysis of the flow field of some materials with different power-law factor in the die designed by Mckelvey was close to that of Mckelvey"s. It was shown that the flow distribution was uniform in the die that can producesheets with 1200mm in width. During the analysis the flow channel was divided into several parts to get the details about the fluid flow in each area. A conclusion was drawn after analyzing the influence of the die pressure on the flow distribution, that the higher pressure is good for the output and bad for the uniformity of the distribution. Simulation of the die applying the cylindrical main runner showed the fact that when the cylinder replaced the cone the change of uniformity was trivial. The uniformity of the non-block flow channel was so poor that the block in the proper position of the die channel was necessary. The project of the die for the wider sheet was put forth, and the analysis of the fluid flow in the die was shown.

本文模拟了圆柱管缝隙流模型的三维流动场，得到了与Middlemen结论一致的流动均匀性，并通过模拟直观地展示了采用阻尼块可以改善挤出均匀性的现象；分析了多种幂率指数的流体在Mckelvey等人设计的流道模型中的流动分布，得到了与Mckelvey的分析结果接近的压力降和流量偏差；本文建立了1200mm幅宽机头流道的三维有限元模型，并逐个分析各个区域和多个截面的流动分布状况，由此揭示了1200mm幅宽L-型机头流道内的流北京化工大学硕士学位论文动分布基本均匀，并在分析了机头压力对于挤出流动分布的影响后得出结论：较高的机头压力可以获得较大的产量，但是不利于物料均匀分布；模拟了采用圆柱管主流道时机头流道内的流动分布，得出结论：主流道由圆锥管改为圆柱管时对流动均匀性影响不大，通过设置适当的阻尼仍然可以达到挤出平衡；模拟了两端进料式圆柱管无阻尼流道的流动均匀性后得到结论：两端进料式无阻尼结构的流动均匀性较差，宽机头中仍然有必要设置阻尼块；确定宽幅机头流道的基本方案，并设计了一种宽幅防水卷材挤出机头流道的结构，通过流动模拟表明该种结构的流动均匀性较好；考察了宽幅机头对于不同厚度片材的挤出适应性，得到结论：当生产不同厚度的片材时，阻尼块高度需要调整。

For the first time, a screw pile and pile driver system for preventing flood and rushing to deal with an emergency was manufactured. The screw piles of the system is different from screw drills used to sap, and it doesn't push soils out. Analyses, including the screw pile's structural strength analysis and the screw blade's welding analysis, were done by ANSYS, which showed that the screw pile's structural strength is enough and that the distort of the screw blade is small. Testing on the screw pile and pile driver system showed that the system performed stably and could meet the need of preventing flood and rushing to deal with an emergency. A mechanics model of interaction of a screw pile and soil was built, and expressions of torque of screw pile's cylindrical part on the condition of screw pile's crew part being driven into soil fully were gained, then the relation of the torque with screw pitch and out diameter of cylinder, which shows the torque decreases with the screw pitch increasing, and that the torque increases with the out diameter of cylinder increasing, which was according with the experiments of the screw pile's being driven into soils, and thus a screw pile with the best structure was chosen. Experiments of bionic surface showed that, on the condition of certain pressure on the surface, the protruding bionic surface can not reduce adhesion and resistance and that the corrugated bionic surface can reduce adhesion and resistance. An orthogonal experiment of the corrugated bionic surface was done with the factors including the width of protrusion, the space between two protrusions, the trolley's velocity and the vertical surface pressure and with the surface frictional coefficient as the experimental target, and some inclusions were drawn that the best combination of the factors was acquired and that the width of protrusion affected the surface frictional coefficient remarkably.

研制了防汛抢险螺旋桩机系统，提高了沉桩作业效率；利用ANSYS对桩体进行整体结构强度分析以及螺旋叶片的焊接分析，表明桩体结构强度足够，焊接过程中，螺旋叶片的变形小；对整个螺旋桩机系统进行试验，表明该系统性能可靠，工作稳定，作业效率高，能够满足防汛抢险沉桩作业基本需要；建立了螺旋桩桩土作用力学模型，得出螺旋桩沉桩过程中螺旋桩螺旋部分完全进入土体时螺旋桩圆柱部分所受扭矩以及扭矩与防汛抢险螺旋桩的螺旋导程和圆柱外径的关系曲线，表明螺旋桩螺旋部分完全进入土体时螺旋桩圆柱部分所受扭矩随着螺旋导程的增大而减小，随着圆柱外径的增大而增大，这与螺旋桩沉桩试验结论相符合，据此优选出最佳结构的螺旋桩；仿生曲面试验表明，尺寸较小的球冠突起型仿生曲面在一定压力作用下未能起到减粘降阻的作用，而尺寸较大的波纹型仿生曲面相对平板具有一定的减粘降阻作用；以波纹型仿生曲面突起宽度、波纹型仿生曲面两突起之间间距、台车的牵引速度以及叶片表面垂直载荷为因素，以曲面摩擦系数试验指标进行正交试验，寻求出在一定试验条件下最佳因素水平组合；波纹型仿生曲面突起宽度在本试验条件下对曲面摩擦系数影响显著，而其它几个因素对曲面摩擦系数影响均不显著；通过波纹型仿生曲面突起宽度和台车牵引速度的单因素试验，表明曲面摩擦系数随着仿生曲面突起宽度的增大而减小，而随着台车牵引速度的变化基本保持不变，和正交试验结果保持一致。

It is found that the position of vortex shedding is different fro m three-row cylinders. The time-mean pressure coefficient along the surfaces o f the cylinders is not changed with the void friction. But the fluctuating press ure coefficient reduces with the increase of void fraction.

试验结果表明：沿圆柱表面周向的旋涡分离点随着流动向深层发展，并向圆柱的背部移动；圆柱表面沿周向的时均压力系数几乎不随含气率的变化而变化；圆柱表面的脉动压力系数随着含气率的增加而减小。

The present invention relates to a kind of tunable plasma resonant cavity for PCVD optical fiber perform rod processing machine. The tunable plasma resonant cavity includes cylindrical resonant cavity casing and cut-off waveguides set on two ends of the casing, and features the tuning piston, which is set on one end of the cylindrical resonant cavity and has middle part with through hole and back end stretched beyond the casing.

本发明涉及一种用于PCVD光纤预制棒加工机床的可调谐等离子体谐振腔，包括有圆柱型谐振腔壳体，在圆柱型谐振腔壳体的两端设置截止波导，其不同之处在于在圆柱型谐振腔腔体的一端安设调谐活塞，调谐活塞的中部开设通孔，后端延伸至圆柱型谐振腔壳体外端。

Do you know, i need you to come back

你知道吗，我需要你回来

Yang yinshu、Wang xiangsheng、Li decang,The first discovery of haemaphysalis conicinna.

1〕 杨银书，王祥生，李德昌。安徽省首次发现嗜群血蜱。