The Finite Element Analysis and Optimum Design of a Moving Central Tray in Railway Vehicle with a Concave Bottom

Through the experiment verified that the hydrodynamic deep drawing technology quality forming a high-lever concave bottom piece of feasibility and achieving high quality forming parts.

通过实验验证了采用充液拉深工艺一次高质量成形内凹底筒形件的可行性，得到了较高质量的成形零件。

The concave bottom mill shoe is used to grind downhole small objects and other unstable fallen objects.

凹底磨鞋可用于磨削井下小件落物以及其它不稳定落物。

FEM Analysis on Warm Extrusion Concave Die of Drilling Bit Shell

凿岩钎头壳体温挤压凹模的有限元分析

So the axial force is reduced, the fixing centre of the concave bit is stable and the concave bit has a long lifetime.

从而减小了轴向力，使钻头定心稳、寿命长，提高了钻削速度和工作效率。

The paper analyses the distribution regulation of air cushion field press and press grade in convex curve and concave curve of air cushion belt conveyor and discusses the curve radial R1 and the effect of belt tension on air cushion field major factors.

本文分析了气垫带式输送机在凸凹弧段运行时，气垫场的压力、压力梯度的分布规律，并讨论了凸凹弧段曲率半径R1，胶带张力对气垫场主参数的影响。

It researched on a practical project based on the design theory educed before, ascertained the radius of convex curve with alterable angles and concave curve with alterable angles, finished the design of disposal structure.

根据所研究出的设计理论，进行一项工程实例的设计研究，确定该实例的凹变坡和凸变坡转弯半径，完成转弯段布置结构设计。

It is found that heat transfer coefficient increases with fin height, while flow resistance varies as concave curve, that is to say, the resistance reaches the lowest value at a middle fin height.

结果表明，随着流道内翅片高度的增大，传热膜系数随之增大，但流阻曲线则呈凹型变化，即在中间高度时流阻达到一最小值。

The diurnal variation of WUE was a concave curve with the highest in the morning, the lowest at noon and high in the afternoon.

杏各品种的WUE日变化总体表现为上午最高、中午最低、下午较高的凹型曲线，但品种间在曲线变化和日均值方面也存在差异。

It can complete variable angle continuously placement, form concave curve surface, change the width of fiber belt.

它可以实现连续变角度铺放，并可成形凹曲面，且纤维带宽可变化。

The research result showed that: With the increase of distance from shield tunnel central axis, the initial excess pore water pressure decreased in a concave curve shape.

分析表明：随着离隧道中心的径向距离增加，土体各点的初始超孔隙水压力呈凹曲线衰减。研究了隧道埋深、盾构直径对土体初始超孔隙水压力的影响。

Single cam linkage mechanism can overcome the shortcomings mentioned above, however the new problem is that the mechanism can not generate the path which has concave curve.

单凸轮连杆组合机构可克服上述缺点，即可以方便地再现预定轨迹并有精确解，但其缺点是难以实现内凹曲线的轨迹复演。

The data also demonstrate that concave slope is more pro runoff production and soil erosion than other slope shapes ( convex, S, linear) under grassland ( alfalfa) conditions.

对于草地（紫花苜蓿）类型，凹坡相对于其它坡型（凸坡，S型，直线坡）最容易产生径流和侵蚀。

Finally get the following conclusions: ① Compared with planar sloped and concave slope, the toppling deformation of convex slope is easier to happen.

分析结果可以得到：①较之凹形坡与平形坡，凸形坡更有利于斜坡的倾倒变形破坏。

That is to say, the concave slope is the most stable, the horizontal slope is the second and the convex slope is the worst.

即在坡度一样的情况下，凹坡最稳定，平坡次之，凸坡稳定性最差。

Propagation of internal waves over linear slope, convex slope and concave slope are discussed by using of the transforms introduced in this dissertation.

利用提出的变换讨论了内波在线性斜坡地形、凸地形和凹地形上的传播特征，分析了入射波能通量在不同模态上的重新分布。

Comparison of the four kinds of slope indicates that the concave slope type is the best oil-bearing one.

通过对4种斜坡的类比表明：凹坡型为最佳含油斜坡。

Design of belt conveyor for concave slope variable turn

凹变坡转弯带式输送机的设计

The external cause is the mother current scouring the concave bank and the lateral circulation scouring the curved river channel.

凹岸部位主流线的顶冲和弯曲河道横向环流的侧蚀，是决口的外部因素；

The design methods of the apron protection for concave bank along subgrade river are effective measures pass through practical application.

通过工程实际应用，证明河湾凹岸路基冲刷防护采用护坦基脚式挡土墙或护坦式基脚护坡是一种经济有效、易行的浅基防护型式。

Concave bank Beach Bar Deposition of Meandering River

曲流河凹岸滩坝沉积模拟研究