查询词典 Mev

Proton events in general only occur in SAA region while electron events appear at both SAA and polar regions.Electron flux of 0 5～2 0?MeV in polar regions is dominant over that of 2～15?MeV,while at SAA,fluxes from the two channels are about the same.There is a close correlation between energetic particle radiation inside and outside the satellite.

与现有理论模型和国外大致相同轨道上的空间高能辐射环境直接观测资料对比还表明，卫星舱内的辐射与舱外的空间辐射环境是完全相关的，积累的有关资料不但是航天设计和环境应用研究所需的重要参量之一，也是空间物理基础研究特别是辐射带研究的重要数据。

The influences of the shock thickness and Alfven waves on the particle acceleration by diffusive shock waves are numerically studied through solving one-dimensional diffusive equation including the second-order Fermi effect. It is shown that the spectral index of the energetic particles strongly depends on the shock thickness. For example, the spectral index increases from 2.1 to 3.7 in the low energy range of 3-10 MeV and from 2.5 to 5.0 in the high energy range of 20-60 MeV as the thickness increases. The spectral index decreases from 4.3 to 3.1 as the particle injection energy increases. The spectral index decreases from 4.0 to 1.8 at the quasi-steady stage with the enhancement of the compression ratio from 2 to 4. The results indicate that under the influence of Alfven waves, the energetic particle spectrum at lower energy becomes flat and the spectral index decreases from 2.5 to 0.6 in the low energy range of 3-10 MeV and from 11.6 to 5.0 in the high energy range of 20-60 MeV. At the same time, the rollover energy reaches 19.6 MeV. The spectral index decreases from 5.8 to 2.9 as the energy density of Alfven waves increase. All these results are basically consistent with the theoretical models, as well as the observations of typical energetic particle events.

通过数值求解包含二阶费米加速的一维扩散方程，探讨在准平行激波条件下激波厚度和级联阿尔芬波对粒子加速的影响，研究粒子分布函数的演化与激波厚度和阿尔芬波强度的内禀关系，计算结果表明：(1)考虑激波厚度时，谱指数明显依赖于激波厚度，随着厚度从0.32增大到2.56，低能端(3-10MeV)谱指数逐渐从2.1增加到3.7，高能端(20-60MeV)谱指数从2.4增大到5.0，能谱逐渐变软；当初始注入粒子动量增大1.3倍，质子能谱指数从4.3减小到3.1，且与零厚度激波加速的谱指数差值缩小；厚度不变时，随着压缩比从2增加到4，准稳态分布时低能端(3-10MeV)粒子能谱指数逐渐从4.0减小到1.8谱变硬；(2)在级联阿尔芬波的影响下，随着时间的增大，粒子在低能处(3-10MeV)的谱指数从2.5减小到0.6高能端(20-60MeV)谱指数从11.6减小到5.0，能谱变硬，拐点能量值从7.5MeV增大到为19.6MeV；随着波的能量密度增大，谱指数从5.8减小到2.9，这表明阿尔芬波强度越大，加速效率越高，通过与激波厚度解析结果和高能粒子事件的观测能谱比较发现两者是一致的，说明数值模拟结果是可靠的。

There is no visible light dispersion in the glass and it can take the place of traditional rare earth fluorescent screen in high energy radiography applications. For its spatial resolution will not be greatly reduced when its thickness increases in a certain range, a thicker glass can be used to reach a higher DQE.

针对特殊用途开发了一种新型掺Tb3+硅酸盐发光玻璃转换屏，可用于30 MeV的γ光子的成像探测；在低能X光(100 keV)作用下的空间分辨能力与301型发光玻璃相当，而在能量高达12 MeV的X光的照射下，其空间分辨能力不低于1.5 lp/mm，发光效率约为301型发光玻璃的3倍。

In order to analyze the neutron spectrum effects on radiation damage, a computer code is designed to calculate recoils, fragments , transmutational products and their energy spectrum.

分析了中子与靶原子的相互作用过程，提出了结合中子输运和核反应耦合模型，采用由蒙特卡罗方法编写的RDSNC程序计算了聚变堆第一壁候选材料SiCf，/SiC在14 MeV和1 MeV中子辐照后的反冲核、碎片、嬗变产物和它们的能谱。

The various effective interactions'(including DDME1,TW99,NL2,TM1,TM2,GL85 and GL97) influence on the constitute, equation of state and mass of neutron star are studied in the framework of relativistic mean field theory considering the interacting nucleons, hyperons and mesons system at finite temperature (T=20 MeV).

从相对论平均场（Relativistic Mean Field，RMF）理论出发，考虑核子、超子和介子的相互作用，研究了一定温度（T=20 MeV）下，各种不同相互作用参数组（DDME1、TW99、NL2、TM1、TM2、GL85和GL97）对中子星物质的粒子组成、状态方程和质量等的影响。

This paper introduces the dust activation status at different positions in NSRL 200 MeV linac tunnel and gives some suggestions for radiation protection as well.

本文简要介绍中国科技大学国家同步辐射实验室200 MeV电子直线加速器隧道内不同地点灰尘的活化现状，并提出相应的防护建议。

Young adult wild type and mev-1 mutant hermaphrodites were exposed to ENIs the density of ENIs was 1×10^5~l.5×l0^5 ionscm^(-3, and the development period, the lifespan, the broodsize and the germline cell apoptotisis of C. elegans were detected. Results showed that the development periods of two C.

将成年野生型和mev-1突变型线虫及新鲜虫卵持续暴露于空气负离子中（空气负离子剂量1×10^5~1.5×10^5 ionscm^(-3)），观察空气负离子暴露对线虫发育周期、寿命、繁殖性能和性腺细胞凋亡的影响。

Young adult wild type and mev-1 mutant hermaphrodites were exposed to ENIs（the density of ENIs was 1×105~1.5×105ions·cm-3）, and the development period, the lifespan, the broodsize and the germline cell apoptotisis of C. elegans were detected. Results showed that the development periods of two C.

将成年野生型和mev-1突变型线虫及新鲜虫卵持续暴露于空气负离子中（空气负离子剂量1×105~1.5×105ions·cm-3），观察空气负离子暴露对线虫发育周期、寿命、繁殖性能和性腺细胞凋亡的影响。

CCL section accelerates the 30 mA, 80 MeV proton beam from the coupled-cavity drift tube linac to 1 GeV.

CCL把来自耦合腔漂移管加速器的30 mA、80 MeV的质子束加速到1 GeV。

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。

We have no common name for a mime of Sophron or Xenarchus and a Socratic Conversation; and we should still be without one even if the imitation in the two instances were in trimeters or elegiacs or some other kind of verse--though it is the way with people to tack on 'poet' to the name of a metre, and talk of elegiac-poets and epic-poets, thinking that they call them poets not by reason of the imitative nature of their work, but indiscriminately by reason of the metre they write in.

索夫农 、森那库斯和苏格拉底式的对话采用的模仿没有一个公共的名称；三音步诗、挽歌体或其他类型的诗的模仿也没有——人们把&诗人&这一名词和格律名称结合到一起，称之为挽歌体诗人或者史诗诗人，他们被称为诗人，似乎只是因为遵守格律写作，而非他们作品的模仿本质。

The relationship between communicative competence and grammar teaching should be that of the ends and the means.

交际能力和语法的关系应该是目标与途径的关系。