正电子

Table 4 Lattice structure, atomic radii, electronic configurations, electronegativities andpositron bulk lifetimes of Fe, Cr, Mo and Al lattices

为便于讨论合金元素对Fe3Al合金缺陷组态和电子密度的影响，我们把Fe、Cr、Mo和Al的电子构型、晶体结构、原子半径、电负性[10]及正电子在其金属基体中的寿命值[11，12]列于表4。

The horizontal axis of a two-dimensional Cartesian coordinate system.PET and SPECT images could be sharper, for example.

例如正电子发射 x射线摄影技术和单光子发射计算机化成像都可更清晰一些。

In some kinds of beta decay, a nuclide loses surplus positive charge by emitting a positron (in the same event, a proton becomes a neutron, and neutrinos are also given off).

以某种贝它衰减，一个核素靠发出一个正电子失去剩余正电荷(在相同的事件中，一个质子变成一个中子，而且也发射微中子)。

Beta particle s are either electrons or positrons.

粒子可以是电子或正电子。

The Positronic Man (1993) is a novel co-written by Isaac Asimov and Robert Silverberg, based on Asimov's novella The Bicentennial Man.

正电子人》（1993）是艾萨克·阿西莫夫与罗伯特西尔弗伯格合著的，此文与阿西莫夫的小说The Bicentennial Man设定相同。

Using H2 15O positron emission tomography, we measured changes in relative regional cerebral blood flow.

使用氧15的水进行正电子断层扫描实验，我们测量了相关的局部脑血流。

ABSTRACT In the first Born approximation, the laser assisted ion-and positron-atom charge exchange collisions are studied.

本文在Born近似下，系统地研究了强激光场中裸离子与正电子对原子的电荷转移过程，在偶极近似下。

The sulfonated polyetherketone with cardo group films made by different sulfonation degrees and solvent evaporation shows different microstructure by PALS and atomic force microscopy.

利用对高分子材料纳米量级自由体积空洞极为灵敏的正电子探针，并辅之原子力显微镜法研究了磺化及溶剂蒸发对酚酞侧基聚芳醚硐膜制备的影响。

A study on the effe ct of slotting technology and surface treatment upon energy resolution for BGO crystal array detector used in positron emission tomography-PET is de scribed.

介绍了用于正电子发射断层扫描仪的阵列式探测器中的BGO晶体开槽工艺和表面处理对探测器能量分辨率影响的研究，并给出了有关的实验结果。

Electrons can be easily injected from thegraphitic matrix into the conduction rand of diamond under the high field which resultedfrom the projection field enhancemext.These injected electrons could reach the vacuumsurface and then emit into vacuum where the negative electron affinity or low electronaffinity could allow the electrons to re emitted more easily.

由于场增强效应，对镶嵌在非晶碳颗粒表面的金刚石晶粒来说，电子在高场作用下通过隧道效应越过金刚石晶粒与非晶碳形成的界面势垒，注入金刚石的导带，在电场的作用下迁移到表面，由于某些金刚石表面具有负电子亲和势或较小的正电子亲和势，电子较易发射进入真空。

Breath, muscle contraction of the buttocks; arch body, as far as possible to hold his head, right leg straight towards the ceiling (peg-leg knee in order to avoid muscle tension).

呼气，收缩臀部肌肉；拱起身体，尽量抬起头来，右腿伸直朝向天花板（膝微屈，以避免肌肉紧张）。

The cost of moving grain food products was unchanged from May, but year over year are up 8%.

粮食产品的运输费用与5月份相比没有变化，但却比去年同期高8％。