对称中心

Handle assembly of small irregular positive speaker, original handle cross-level vertical holes, all with the centro-symmetric.

组装手柄正面的扬声器小孔不整齐，原装手柄的小孔横平竖直，处处与中心对称。

We find that optical vortices could be efficiently formed and generated due to the interference and superposition effect of all the beamlets, during the propagation process of the coherent radial laser arrays with the initial well-organized phase distributions through the free space, the resulted beam in the far field has the strong rotation effect with the phase helicity.

我们发现具有确定初始相位的、圆径向对称分布的相干激光阵列光束在传播的过程中由于干涉和叠加效应可以形成螺旋形的位相分布且保持光束中心强度为零，即形成光涡旋。

Based on the abundant characteristic structures and the high percentage ofnon-centrosymmetric compounds, borates and porophosphstes are the good field to search fornew non-linear optical materials.

硼酸盐和硼磷酸盐不仅有丰富的结构和独特的结构特征，而且非中心对称化合物占有较高的比例，是探索新的非线性光学晶体材料很好的搜索源。

Shape carabiners are stronger and lighter than ovals, given the same materials. The asymmetrical design ensures that loads are held off-center, toward the stronger, non-gated side.

型钩环的强度最强且比同材料的O形钩环轻，不对称的设计使负载物不会在中心，而移到开口的另一侧强度最强的地方。

The appearance of the ossification centers and fusing of epiphyses of bones of both hands and wrists occur symmetrically at a higher ratio.

手、腕部双手骨化中心出现及干骺愈合对称率较高。

Conclu-sion: The appearance of the ossification centers and fusing of epiphyses of bones of both handsand wrists occur symmetrically at a higher ratio.

手、腕部双手骨化中心出现及干骺愈合对称率较高。

A systematic analysis of the icosahedral hierarchic structure in the 3D icosahedral quasicrystal and its approximants have been made. There is an icosahedron at the center surrounded by 12 icosahedra. If two neighboring icosahedra are vertex-sharing, the multi-shell Mackay cluster consisting of 127 atoms will form. If two neighboring icosahedra penetrate into each other, the multi-shell Samson-Bergman-Pauling cluster consisting of 137 atoms will form.

系统地分析了三维二十面体准晶的近似晶体相中具有二十面体对称的等级结构，中心1个二十面体，周边12个二十面体，如两个相邻二十面体共顶点连接，得出的是由127个原子构成的Mackay球形原子簇；如两个二十面体互相穿插，得出的是由137个原子构成的Samson-Bergman-Pauling球形原子簇。

Our investigation has shown that:ⅰ there was an interference effect between the incident and reflected matter waves as all the atoms in BECs were coherent;ⅱ considering the rotation of a vortex, the nonuniform velocity distribution along the surface would play an important role in the quantum reflection process. For example, they would change the characteristics of the interference fringes between the incident and reflected matter waves;ⅲ the reflected vortex became unstable for sufficiently low incident velocity or strong interaction. This sort of instability physically originated from dynamics excitations induced by the atomic interaction in the quantum reflection process.

我们的研究表明：ⅰ由于相干性质的存在，在涡旋与固体表面相互作用的过程中，被固体表面反射回去的部分与正在入射的部分在空间叠加后一定会产生清晰的干涉条纹；ⅱ由于各向异性的速度分布，涡旋的反射率也呈各向异性，因此反射回来的部分与入射部分形成的干涉条纹宽度以及疏密程度与入射速度以及速度各向异性的程度有关；ⅲ由于玻色凝聚体中原子间相互作用的存在，反射过程中凝聚体会产生激发，破坏涡旋的结构，使得反射后的涡旋不再是中心对称。

During vacation, he saw Wang's QQ Log Lane wrote: Today, I have devised two fruit stalls, are the center symmetric, the middle is the bow and the sun.

放假期间，看见泓的QQ日志里写到：今天，我设计了两个水果拼盘，都是中心对称式，中间是蝴蝶结和太阳。

It will take important influence to the launch rate, the launch denseness and the campaign efficiency of rocket gun applying the symmetrical launch method.

对称发射法是将离摇架中心较远的定向管一一对应同时发射，其应用会对火箭炮发射速度和密集度及作战效能带来重要影响。

On the other hand, the more important thing is because the urban housing is a kind of heterogeneity products.

另一方面，更重要的是由于城市住房是一种异质性产品。

Climate histogram is the fall that collects place measure calm value, cent serves as cross axle for a few equal interval, the area that the frequency that the value appears according to place is accumulated and becomes will be determined inside each interval, discharge the graph that rise with post, also be called histogram.

气候直方图是将所收集的降水量测定值，分为几个相等的区间作为横轴，并将各区间内所测定值依所出现的次数累积而成的面积，用柱子排起来的图形，也叫做柱状图。