梯形的

The macro conjugated molecule fluorene derivative has 2, 3, 6, 7-tetraamino-9, 9'-dialkyl fluorene as a raw material which is added to an organic solvent respectively together with phenanthrenequinone, acenaphthene quinone or bis-carbonyl pyrene derivatives and strong base; under the protection of inert gas, reflux reaction is carried out to the materials, so as to prepare a series of trapezoidal conjugated molecules containing fluorine structures.

本发明涉及一类含大共轭分子的芴衍生物及其制备方法，大共轭分子芴衍生物是将原料2，3，6，7-四氨基-9，9'-二烷基芴，分别与菲醌、苊醌或二羰基芘的衍生物以及强碱加入到有机溶剂中，在惰性气体的保护下，回流反应制得一系列含有芴结构的梯形共轭分子。

This paper introduces the optimum design idea widely used in mechanics especially in automobile at present, Firstly explicating one particular optimum method for this automobile steering gear design.

摘要本文首先介绍目前在机械行业尤其是汽车行业中应用较广的最优化设计思想并且针对本次汽车转向梯形臂的设计的一种具体方法作了详细的阐述。

Based on the practical process, this paper presented a method to compute the deceleration distance in real time.

基于插补的实际情况，给出一种实时计算减速距离的方法，在此基础上，实现了基于梯形速度曲线的速度平滑处理以及基于S形速度曲线的加速度平滑处理。

Stability of implants was measured by rfa regularly.results there was no significant difference between both groups about stability at all periods and histomorphometry, but isq, bic and ba of experimental group were higher than control group, and isq recovered more quickly in experimental group after loaded.conclusion dual threads design contributes to assure the initial and secondary stability of implants, which is particularly important in poor density bone.

结果 两组种植体在各时期的稳定度差异均无显著性，但在每一时期实验组种植体的稳定度均较对照组高，实验组种植体在负重后稳定度恢复较快，负重3个月后实验组的骨-种植体接触率和种植体周围骨面积均较对照组稍高，但两者差异无显著性。结论双梯形螺纹种植体有利于保证种植体的初期和后期稳定性，应用于低密度骨质优越性会更加明显。

In the case of growth on the ploycrystalline diamond substrates under high methane concentration condition, diamond nano-platelets consisting of many smaller tabular crystallites with various shapes but with the same facets, such as trapezoid and parallelogram, appear in terrace and step structure on tabular surface.

在高甲烷浓度条件，多晶钻石基材上成长的奈米平板钻石，其外形结构是由各种形状(近似於梯形及平行四边形)的小平板组合而成，并且这些小平板会在平板钻石表面形成平台及台阶的结构。

In order to study the speed control performance of multiphase trapezoidal-wave permanent magnet synchronous motor, the mathematical model was established based on the six-phase TPMSM with Y-Y winding shifting 30° electric-degree.

为了研究多相梯形波永磁同步电动机的调速性能，基于Y-Y移30°电角度的六相TPMSM建立数学模型，在Simulink仿真环境下设计了TPMSM的电流型自控频率式调速系统。

In the training of students making echelon screw thread by turning,the choosing and grinding of knife,putting knife into nip,putting workpiece into nip should be noticed;the lathe,choice of technics parameter,establishment of working steps should be adjusted.

在训练学生车削梯形螺纹时，要注意车刀的选择与刃磨、车刀的装夹、工件的装夹，要调整车床、选择工艺参数、确定工步。

The distance between the eastern and western sides extends over 1800 meters, and the total length of the southern city wall measures about 2000 meters and became a city protected from all sides; by the city walls in the east, west and south, and by the Yazi River in the north.

复原后的三星堆古城平面略呈北窄南宽的梯形，城东西长度在1800米以上，南城墙长约2000米，城内面积达3.5平方千米，形成了由东、西、南三面城墙及北侧鸭子河为防御体系的古城。

Since RKPM is a kind of Galerkin meshfree methods, in this thesis, penaltyfunction method is employed to enforce the essential boundary conditions,trapezoidal rule is used for the approximation of displacement field function, Gaussand Hammer quadratures are applied for the numerical integration of systemequation,self-adapting method is applied for confirming the support of the pointinterpolated.

针对 RKPM 是一种伽辽金型的无网格方法，本论文采用罚函数法引入位移边界条件，用梯形积分法则近似位移场函数，对系统方程进行积分时分别使用了 Gauss 积分和 Hammer 积分，采用自适应的方法确定计算点的定义域。

This paper adopts the trapezoidal asympotic formula, and provides a novel formulation deduced for the functions, which takes the influence of the singularities into account, like Romberg method.

通过推导该类函数积分的梯形公式的渐进估计式，得到了考虑奇点影响的外推算法－类Romberg算法。

However, as the name（read－only memory）implies, CD disks cannot be written onorchanged in any way.

然而，正如其名字所指出的那样，CD盘不能写，也不能用任何方式改变其内容。

Galvanizes steel pallet is mainly export which suits standard packing of European Union, the North America. galvanizes steel pallet is suitable to heavy rack. Pallet surface can design plate type, corrugated and the gap form, satisfies the different requirements.

镀锌钢托盘多用于出口，替代木托盘，免薰蒸，符合欧盟、北美各国对出口货物包装材料的法令要求；喷涂钢托盘适用于重载上货架之用，托盘表面根据需要制作成平板状、波纹状及间隔形式，满足不同的使用要求。