同中心

The Fresnel lens, also known as the dioptric lens, consists of a central glass disk and concentric glass rings or a central glass band surrounded by parallel glass rings.

一个在中心的玻璃圆片和与之同圆心的层层玻璃圆环，或者中间是一个玻璃带，两边是与之平行的玻璃带状环。

Compared with the same wave problems with conventional Dirichlet boundary conditions, the absorbing boundary conditions can reduce the numerical reflection on boundaries and avoid solution distortion. In addition, the central differences method is economic in memory requirement and computing time compared with implicit integral method.

结果表明：该解法在空间上具有谱精度，在时间上达到二阶精度；与第一类边界条件相比，吸收边界有效地削弱了边界上的数值反射，避免了解的失真；使用中心差分的时间积分方法同隐式积分方法相比，适合波的传播特性，避免了矩阵求逆运算，并且占用的计算机内存小。

The truncation error of CSCD is derived and compared with some symmetric finite difference methods having the same order of accuracy,which shows that CSCD has the smallest coefficients in error terms.

从定性角度，得出同阶中心差分格式中，CSCD格式的截断误差系数最小的结论。

He holds that it is quite necessary to distinguish between ancient Chinese exegetics and Chinese lexical history, and that the study of the evolution of basic word stock should be regarded as the chief branch of Chinese historical lexicology, as changes in basic vocabulary is as much important to a language as those in phonological system and qrammatical structure.

文章认为：汉语史研究中把训诂学与词汇史混为一谈的现状亟需改变；汉语词汇史应以探讨常用词的演变更替为中心内容；常用词的变化对词汇系统乃至整个语言系统而言都是一种带根本性的深层次变化，具有同音韵系统、语法结构的改变同等重要的意义；常用词演变的研究与古籍整理和大型语文辞书的编纂也有着密切的关系。

One such center is the Rotary Rajan Eye Bank. It operates in cooperation with the Rajan Eye Care Hospital in Chennai.

扶轮社Rajan眼科银行就是这样的中心，它同钦奈Rajan眼科护理医院有合作关系。

Asia is young, terminally hip, utterly digital, educated in business, on the way to rich, casually multi-lingual, materialistic by default setting, transparently shallow yet fetchingly friendly, star-struck, fame-centric, in a desperate hurry, fascinated with America as a role model and yet set to absorb our best ideas, spin them one turn better and, before we know it, pass us like a bullet train.

年轻亚洲，终极时尚，绝对数码，商业精英，富裕坦途，多语自如，金属设计的默认设置，无心计但动人地友好，明星冲击，荣耀中心，迫不及待，同美国作为模特角色令人着迷并已吸收我们最好的观念，编制变得更好并且，在我么知道之前，像子弹头列车一样穿过我们。

President-elect Bill Clinton sang Don't Stop with Jackson and Fleetwood Mac's Stevie Nicks at the Presidential Gala at the Capital Centre on Jan.

年1 月19 日首都中心，当选总统比尔·克林顿在其就职庆祝舞会上同杰克逊以及弗利特伍德麦克乐队的史蒂维·尼克斯合唱《不要停止》。

President-elect Bill Clinton sang Don't Stop with Jacksonand Fleetwood Mac's Stevie Nicks at the Presidential Gala at the CapitalCentre on Jan.

年1 月19日首都中心，当选总统比尔·克林顿在其就职庆祝舞会上同杰克逊以及弗利特伍德麦克乐队的史蒂维·尼克斯合唱《不要停止》。

LQRY series hot oil pump is the second generation developed on the basis of the oil pumps abroad, basically structured as single stage single entry overhung foot supported. Pump inlet is axial suction, and outlet has its center vertically upward, which are mounted, together with the motor, at the bottom.

LQRY系列热油泵是本单位消化吸收国外油泵的基础上研制的第二代产品，基本结构形式为单级单吸悬臂式脚支撑结构，泵的进口为轴向吸入，出口为中心垂直向上，和电机同装于底座上。

QCRY series hot oil pump is the second generation developed on the basis of the oil pumps abroad, basically structured as single stage single entry overhung foot supported. Pump inlet is axial suction, and outlet has its center vertically upward, which are mounted, together with the motor, at the bottom.

QCRY系列热油泵是本单位消化吸收国外油泵的基础上研制的第二代产品，基本结构形式为单级单吸悬臂式脚支撑结构，泵的进口为轴向吸入，出口为中心垂直向上，和电机同装于底座上。

Singer Leona Lewis and former Led Zeppelin guitarist Jimmy Page emerged as the bus transformed into a grass-covered carnival float, and the pair combined for a rendition of "Whole Lotta Love".

歌手leona刘易斯和前率领的飞艇的吉他手吉米页出现巴士转化为基层所涵盖的嘉年华花车，和一双合并为一移交&整个lotta爱&。

This is Kate, and that's Erin.

这是凯特，那个是爱朗。