十二面体的

The last but not least, it is also owning to the rapid development in computer science and information technology. Such as, some computational task, which previously must be executed by using super-computer, now can be carried out by personal computer, and at the same time, the network speed and band width of data bus and input/output equipment have increased several times. In addition, the improvement of the high quality graphic displaying is available. All these provide strong support for cryoEM high-resolution reconstruction study.

目前，在低电子剂量的情况下，冷冻电镜照片可以记录到3-4 〓的信息，使用冷冻电子显微镜进行高分辨三维重构工作，已经获得6.5-8〓高分辨率水平的结果，可以分辨出蛋白质的α螺旋、识别出蛋白质的β折叠等蛋白质二级结构；其次是，三维重构算法效能的不断提高，使得对二十面体取向和中心参数计算的可靠性大大提高；再次是，由于计算机和信息技术迅猛发展，例如，以往需要使用大型计算机的计算任务已经可以被一般的个人电脑完成，网络速度、数据总线和硬盘等I／O设备的带宽成倍增长，以及图像显示能力的提高都为冷冻电子显微镜高分辨三维重构技术提供了强有力的支持。

Nowadays, in the low electron dose condition, the information about 3-4〓 can be recorded on the cryoEM micrograph, and the high-resolution reconstruction using the cryoEM has reached 6. 5-8〓 levels. The reconstruction can reveal the protein α helical and recognise β fold secondary structure. Secondly, it is due to the development in 3D reconstruction method, which can be more efficient to determine the orientation and center parameters. The last but not least, it is also owning to the rapid development in computer science and information technology. Such as, some computational task, which previously must be executed by using super-computer, now can be carried out by personal computer, and at the same time, the network speed and band width of data bus and input/output equipment have increased several times. In addition, the improvement of the high quality graphic displaying is available. All these provide strong support for cryoEM high-resolution reconstruction study.

目前，在低电子剂量的情况下，冷冻电镜照片可以记录到3-4 〓的信息，使用冷冻电子显微镜进行高分辨三维重构工作，已经获得6.5-8〓高分辨率水平的结果，可以分辨出蛋白质的α螺旋、识别出蛋白质的β折叠等蛋白质二级结构；其次是，三维重构算法效能的不断提高，使得对二十面体取向和中心参数计算的可靠性大大提高；再次是，由于计算机和信息技术迅猛发展，例如，以往需要使用大型计算机的计算任务已经可以被一般的个人电脑完成，网络速度、数据总线和硬盘等I／O设备的带宽成倍增长，以及图像显示能力的提高都为冷冻电子显微镜高分辨三维重构技术提供了强有力的支持。

A great number of viruses' capsid proteins are efficient assembly into icosahedral symmetry structures. The capsid structures obey the quasi-equivalence theory of Caspar-Klug, and they are directly composed of pentagons and hexagons.

摘 要 绝大多数病毒的衣壳蛋白装配成二十面体对称的结构，其衣壳结构遵从 Caspar-Klug 的准等价原理，即是由五边形和六边形直接拼接而成的几何构型。

I didn't watch TV last night, because it .

昨晚我没有看电视，因为电视机坏了。

Since this year, in a lot of villages of Beijing, TV of elevator liquid crystal was removed.

今年以来，在北京的很多小区里，电梯液晶电视被撤了下来。