查询词典 positron

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:a high-speed electron or positron, especially one emitted in radioactive decay ."

粒子：一种高速电子或质子，主要在放射衰变中释放出。

"Beta particle:a high-speed electron or positron, especially one emit ted in radioactive decay."

粒子：一种高速电子或质子，主要在放射衰变中释放出。

Siemens Biograph PET/CT is a combined positron emission tomography and computed tomography system,and combined PET/CT systems are taking place of single PET to be the main choice of clinical application.

Biograph 系列扫描仪是西门子公司研制的高性能 PET 和螺旋 CT 一体化的混合 PET/CT 扫描系统，PET/CT 混合成像系统正在取代单独 PET 系统成为临床应用的主要选择。

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 bremsstrahlung in the Beijing Electron Positron Collider is one of the most important projects for the defense of beams in the synchrotron radiation facilities.

随着自由电子激光、同步辐射光源及高能加速器的建设，高能加速器在各种领域里面越来越广泛的被应用。

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。

In this paper, using Doppler broadening positron annihilation technique investigates the effect of multiple implanting and oxygen concentration variation during.

通过多普勒增宽正电子湮没测试，不同剂量和能量注入、退火后的样品其顶层Si中的氧相关缺陷有着不同的性质。

Fist of all, an advanced positron annihilation coincidence Doppler broadening system was designed and developed and a peak to background ratio of 3.6×10~6 was obtained.

首先我们设计研制了一套高性能的正电子湮没符合多普勒测量系统，其峰谷比可达到3.6×10~6。

Cable dampener cannot be rolled up but must be hung over the cable.

缆帆不能被卷起，必须保证处于展开状态

"This skylark is a present from my master," he says.

"这只云雀是我主人献上的礼物。"他说。