查询词典 X-rays

To make paper more systematic and practical, this paper has first introduced the development history of CT equipment, then, elaborate construction of system and theworking principle of CT equipment systematically, including the property of X-ray, the absorption law of X-ray for materials, the reconstruction principle of CT image, the structure of software and hardware for CT equipment. Finally, with 2 CT systems that we used, statistic and analysis of all the malfunctions which have carried out in passed 10 years was given, and according to the systematic parts of fault located, classify the malfunctions, then elaborate their working principle one by one, analyze the regularity and the characteristic of each malfunction, and put forward specific prevention method and measure for the malfunction.

为了使论文更具系统性和实用性，本论文首先介绍了CT设备的发展史，然后比较系统地阐述CT设备的工作原理及系统结构，包括X射线的特性和物质对x射线的吸收规律，CT图像的重建原理，CT设备的软、硬件结构等，最后以我们所使用的2台CT为例，对10余年来所出现的故障进行了全面的统计分析，并按故障所处的系统部件进行分类，然后逐个阐述其工作原理，分析其故障的特点和规律，并就这些故障提出具体的预防方法和措施。

Alternatively, the spectral softening above 2 GeV could be due to gamma-ray absorption via photon-photon pair production on the soft X-ray photon field of the host active galactic nucleus, but such an interpretation would require the dissipation region to be located very close (l~100 gravitational radii) to the black hole, which would be inconsistent with the X-ray spectrum of the source.

另外的关于2 GeV以上能谱变软的可能解释是高能光子和寄主活动星系核的软X射线辐射场通过电子对产生反应而被吸收，但是这个解释要求反应区域要很靠近中心黑洞(1~100倍引力半径)，这和3C 454.3的X射线测量谱相矛盾。

A new concept of the X-M-PN space is introduced, and the acute angle principle in the X-M-PN space is proved.

提出了X-M-PN空间的新概念，在X-M-PN空间中证明了锐角原理，同时得到了若干新的结果。

If the acute angle of the parallelogram is x , find x .

该平 四边形的锐角是 x°，求 x。

Ve reviewed X-oom PSP Media Suite and concludes with rating of 4 out of 5 that it's not perfect, but used advisedly, X-oom's PSP Media Suite can really let PSP owners make the most of their console's multimedia functions.

审查维生素E的X oom PSP媒体套件，并得出结论，与评级， 4 ， 5 ，它的并非十全十美，但使用advisedly ，的X oom的PSP媒体套房真的可以让PSP的业主，使他们的大部分控制台多媒体功能。

The number for which a given logarithm stands; for example, where log x equals y, the x is the antilogarithm of y.

反对数，逆对数一个特定对数代表的数字；例如，如x的对数等于y那么x就是y的反对数

Arc sine x is an angle whose sine is x.

反正弦x是一个其弦为x的角。

Shots' experimental results show that the X-ray calorimeters are stable, the sensitivity of calorimeter is (84.1±3.4)μV/mJ and the related combined standard uncertainty in the X-ray energy measure is about 31%.

结果表明：X光量热计性能稳定，其灵敏度？？84.1±3.4μV/mJ，X光能量测量的相对合成标准不确定度约为31%，可用于X光定量测量。

Two soft X-ray spectrometers were used to measure X-ray radiation from the primary and secondary disks, respectively.

采用两台软X射线谱仪分别对初级和次级辐射的X射线进行测量，采用X射线条纹相机测量双盘靶等离子体喷射的时空扫描图象，并对实验结果进行简单的物理分析。

This paper introduces the studies of the ultra-short Thomson scattering X-ray source at the accelerator laboratory of Tsinghua University in recent years. Properties such as the photon yield,the pulse length and time jitter of the produced photon pulse were predicted theoretically from the parameters of the electron bunch and the laser pulse,and the scattering angle. Preliminary experiments were successfully carried out with a 16 MeV backward-traveling-wave accelerator and the ns-Q switched laser provided by China Academy of Engineering Physics. This paper also introduces the 1.6-cell electron gun that was fabricated on site and the experiment with high RF power including the measurement of the electron bunche parameters. Based on these,we have designed an X-ray source,which is now under construction.

介绍了清华大学加速器实验室近年来关于汤姆逊散射超短X射线源的研究工作；研究了在任意散射角度下电子束参数和激光束参数对散射光子参数的影响，给出了散射光子的参数如光子产额、脉冲长度、时间抖动等与电子束参数、激光束参数和散射角度的关系；利用实验室已有的16 MeV反波行波加速器与中国工程物理研究院激光聚变研究中心提供的ns调Q激光搭建了汤姆逊散射初步实验平台并开展了实验研究；加工了1.6-cell光阴极微波电子枪，搭建了高功率实验平台，对产生的电子束参数进行了初步测量；对汤姆逊散射超短X射线源进行了设计并开展了相关的平台建设工作，对产生的X射线脉冲参数进行了模拟。

According to the clear water experiment, aeration performance of the new equipment is good with high total oxygen transfer coefficient and oxygen utilization ratio.

曝气设备的动力效率在叶轮转速为120rpm～150rpm时取得最大值，此时氧利用率和充氧能力也具有较高值。

The environmental stability of that world - including its crushing pressures and icy darkness - means that some of its most famous inhabitants have survived for eons as evolutionary throwbacks, their bodies undergoing little change.

稳定的海底环境─包括能把人压扁的压力和冰冷的黑暗─意谓海底某些最知名的栖居生物已以演化返祖的样态活了万世，形体几无变化。