变变

In the single crystal of C60 with a FCC structure,positron mainly appears outside the C60 molecule.The main annihilation space is the interspace between molecules.The calculated positron bulk lifetime in C60 is 352ps, which agrees with experiment value of 356ps in literature.In carbon nanotube bundles with different dimeters,as the diameter of carbon nanotubes increases,the main space where positron appears changes from the interspace of carbon tubes to the space inside carbon tubes,the radio between positron annihilation with valence eletrons and core eletrons becomes larger,the positron bulk lifetime in carbon nanotube increase rapidly first and come to be a constant at the end.The calculated positron lifetime of carbon nanotube with a dimeter of 0.8～1.6ns is 332～470ps,which agrees with the experiment value of 394ps.Positron annihilation has been studied in widly used compound semiconductors.

计算结果表明：在片层结构的石墨晶体中，正电子主要在石墨层间的空隙中湮没，计算出的石墨中的正电子寿命为208 pS，与文献中的实验结果215 ps符合很好；在金刚石单晶中，正电子主要在碳原子之间的空隙中存在并发生湮没，计算出的金刚石中的正电子寿命为115 ps，文献中的实验结果110 ps左右符合；在面心立方结构的C60晶体中，正电子主要在C60分子球壳内外侧及分子之间存在，C60球形分子中心正电子分布很少，正电子的湮没区域集中在C60分子之间的空隙区域，计算出的C60中的正电子寿命为352 ps与文献中的实验结果356ps相符合；对于不同管径碳米管束中的正电子分布，随着碳纳米管直径的增加，碳纳米管束中的正电子由主要在碳纳米管管间的区域出现转变为主要在碳纳米管管内中心的区域出现：碳纳米管束中的正电子与碳原子的价电子的湮没概率变得越来越大，与核心电子的湮没概率变得越来越小；碳纳米管束中正电子的湮没寿命先迅速增大，而后趋于一定值。

SW620/pRETRO-On-TRAIL cells become round and small,dioptre of ellsbroken cells increase.

用相差显微镜观察细胞形态发现，SW620/pRETRO-On-TRAIL细胞经四环素诱导后，变圆变小，贴壁性差，折光性强，细胞碎片增多。

Compared with the diploidy, the morphology and leaves stoma had changed, its leaves became thicker , more coarse , and leaves stoma became significantly bigger.

同时获得一定的变异材料，与正常二倍体相比，其叶片变粗，生长迟缓，气孔器变大，初步鉴定为多倍体。

According to the creep characteristic of concrete,the exponential function was selected as base function,which could construct the prevalent Dirichlet series so as to fit creep coefficient .

根据砼的徐变特性，选用指数函数作为基函数，构造了最普遍的Dirichlet级数形式来拟合徐变系数。

RESULTS: The following changes were found under light microscopy in keratoconus:thin epithelium and stroma,local rupture or destruction in basement membranes and Bowman"s layer,basal cell swollen,stroma disarrangement,ruptures or folds in the Descemet"s membrane and thin endothelium layer.

结果 光镜观察结果，圆锥角膜上皮层、基质层变薄，基底膜及前弹力层局限性断裂或破坏，上皮基底细胞水肿，角膜基质排列紊乱，后弹力膜皱褶或断裂，内皮细胞变薄。

Objective To study the glycosaminoglycancontent and its percentage composition in annuli fibrosus of normal and degenerated intervertebral disci,and to discuss the pathogenesis of degeneration of intervertebral disc.

目的 研究正常和退变腰椎间盘纤维环中糖胺多糖含量及其主要成份百分组成，探讨椎间盘退变的发生机理。

In this paper,according to the polytropic spectral characteristics and physicochemical characteristics of neodymium,the effect of neodymium on color generation of discolour glaze was systematically probed,the reason and mechanism of neodymium discolourment in glaze were elaborated,so as to be helpful to the development of discolour glaze and its theoretical research.

根据氧化钕独特多变的光谱特征及物理化学特征，探讨了钕对变色釉呈色的影响，阐述了其在釉中的变色原因及其机理，对变色釉的开发和理论研究有一定指导意义。

The invention resolves defects of discommodity of heat supply speed adjustment of phase-changing floor energy storage mode, finity of phase-changing material availability, and the invention effectively decreases thermal transmission damage of floor heating downwards.

本发明解决了相变地板蓄能方式供暖速率调节不便、相变材料有效利用率有限等缺点，并有效减小了地板采暖向下的传热损失。

In order to meet the required simulation precision and meet the real-time simulation in ballistic simulation calculation,this paper analyzes the selection method of the simulation step,and then introduces variable step integration methods in Runge-Kutta to Adams and educes Adams variable step integral formulas,and then put forwards a method by seeking zero of condition function in discontinuous nonlinear system of the ballistic simulation.

在弹道仿真计算中，为了既达到要求的仿真精度又能满足实时仿真，分析了仿真步长的选择方法，然后在龙格－库塔转阿当姆斯法中引入变步长积分方法，推导了阿当姆斯变步长积分公式，同时对弹道仿真中的间断非线性系统提出条件函数求零的方法来解算弹道。

As the mechanized view of the body and the germ theory of disease began to become more accepted along with the belief that chemicals and drugs were the way of the future, the attacks became more frequent, bold and progressed to outright lies at times.

由于机械化机构的意见和胚芽理论的疾病开始变得更为人所接受，随着相信，化学品和药品的方式，未来的攻击变得更加频繁，大胆和进步弥天大谎时候。

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。