查询词典 delayed neutron

The data were applied to simulate the neutron energy spectrum and angular distribution of Lanzhou University 3×10^12 s^(-1) intense neutron generator with 260 keV deuteron beam using MCNP. The interactions of neutron and the materials of neutron generator and laboratary wall were included in this MCNP simulation. The simulation results on the neutron energy spectrum and angular distribution of Lanzhou University 3×10^12 s^(-1) intense neutron generator with 260 keV deuteron beam were presented.

以分割法计算得到的能谱和角分布数据为基础，建立了D-T中子源Monte-Carlo模拟抽样模型，在考虑中子发生器各元件材料及实验大厅墙壁对快中子的慢化、散射和吸收的条件下，采用MCNP程序对兰州大学3×10^12s^(-1)强流中子发生器260 keV氘束流能量下的中子能谱和角分布进行了模拟，给出了模拟结果。

By systematically analyzing the single particle level and the occupation probability near the Fermi surface,and the rule of nuclear particle number deviations with proton numbers for N =8,20,28,50,82,126 neutron chains within the relativistic mean-field model with BCS theory,we have discussed the stability of the shell structure for the traditional neutron magic in the whole range of nuclear spectrum from neutron line to proton line,and predicted that traditional neutron magic number effect shall possibly disappear only in light neutron-rich nuclei.

在考虑了BCS理论的相对论平均场模型框架内，通过系统研究 N =8，20，28，50，82和126六条同中子素链中每个元素费米面附近的单粒子能级间隔、粒子数占有概率比以及原子核体系的粒子数偏离随质子数的变化规律，讨论了传统中子幻数的壳结构在从中子滴线区到质子滴线区整个核谱上的稳定性，预言只有在轻核的丰中子区域，传统的中子幻数效应才可能消失，并把计算结果和最近的文献报道作了比较。

The accumulated self-exciting dose for Na-24 is only 1.12 mGy during its average life-time for irradiation of total thermal neutron fluence of 3.6E12 nth/cm^2. Conclusions: Because of the self-exciting dose reduced from neutron activation can be neglected for gamma dose measurement in neutron and gamma mixed field, and the threshold of linear response is 2 Gy, the FWT-70-40 dosimeter not only can be used for high dose rate Co-60 irradiation field and the high energy electron beam for medical purpose, but also can be used for gamma dose measurement in an epithermal neutron beam for boron neutron capture therapy.

型号FWT-70-4OM）剂量计於BNCT高中子通量与剂量的中子、加马混合辐射场所产生的自激剂量，对加马剂量度量干扰可忽略，且对加马的最低剂量限值为2Gy，因此除可应用於钴60加马高剂量辐射场与放射治疗用高能量、高剂量电子射束的剂量度量外，亦可应用於BNCT照射治疗用高能量、高剂量的中子、加马混合辐射场的加马剂量度量。

Considering the fuel salt flow effect of the molten salt reactor, the neutron dynamic model was derived based on the particle conservation equations, and the critical problem was calculated by numerical method under three working conditions to study the flow effect to effective multiplication factor, fast neutron, thermal neutron and delayed neutron precursors distribution.

考虑新概念熔盐堆燃料盐的流动特性，从基本的粒子守恒方程出发，推导了熔盐堆的中子动力学模型，并采用数值方法对3种工况下熔盐堆的临界问题进行计算，考察流动对有效增殖系数、快中子分布、热中子分布及缓发中子先驱核分布的影响。

In the paper, a way of amending λ was introduced to solve the point-reactor neutron kinetics equations so that the numerical solution of single-group delayed neutron model is closed to that of six groups delayed neutron model when a positive step changed reactivity was introduced.

通过修正单组缓发中子先驱核衰变常量λ值，使点堆中子动力学方程单组缓发中子模型在正反应性阶跃输入时的数值计算结果趋近于六组缓发中子模型数值计算结果。

Based on the comparison of the delayed neutron counter rate of known fission rate with the delayed neutron counter rate of a burst,a method to determine burst total fission number of burst reactor was built.

用长计数器测量已知裂变率的缓发中子计数率，然后用同一探测系统测量脉冲后的缓发中子计数率，探测系统的探测效率、缓发中子份额和缓发中子先驱核半衰期等参数均不变，从而建立起利用脉冲堆脉冲后的缓发中子衰减曲线确定脉冲裂变总数的方法。

Based on the structure and principle of the CEFR delayed neutron detection system, a calculating model of the delayed neutron detection signal was proposed.

根据中国实验快堆缓发中子探测系统的结构特点和探测原理，构建了缓发中子探测系统的计算模型。

The analysis shows that when λ is amended the resolution of single group delayed neutron model is approximately equal to the numerical solution of six groups delayed neutron model, which meets engineering accuracy.

结果表明：采用修正后的单组解析方法计算阶跃正反应性输入的中子密度响应，计算结果与六组的接近，满足工程计算精度要求，同时计算简便，避免了刚性问题，可以实现快速计算。

The high-correctness C/O energy spectrum logging system features use of fast neutron in deuterium and tritium reaction along with alpha particles flying technique to log, and is composed of neutron counter tube accompanied by alpha particles test system, neutron shielder, gamma ray detector, fact electric timer and computer for data acquisition, processing and control.

本发明提供一种高准确度的碳／氧比能谱测井系统，该系统是将氘氚反应快中子伴随α粒子飞行时间技术用于碳／氧比能谱测井，包括具有伴随α粒子探测系统的中子管，中子屏蔽体，γ射线探测器，快电子学定时部件以及数据获取、处理和控制计算机。

It includes: the selection of detector crystal, the design of geometrical dimension of the detector, the magnetic shield of detector, shield of fast neutron and thermal neutron, distribution of fast neutron in formation, the investigation depth of logging tools and the spacing.

本文第三章介绍了对双晶C/O能谱测井仪研制过程中遇到的主要物理问题进行研究的情况，内容包括：探测器晶体选择、探测器几何尺寸设计、探测器磁屏蔽研究、快中子屏蔽、热中子屏蔽、快中子地层分布、仪器探测深度及源距等。

A historical region of southwest France between the Pyrenees and the Garonne River. The duchy of Aquitaine was joined with France after the marriage of Eleanor of Aquitaine to King Louis VII in1137, but its possession was disputed after her subsequent marriage to Henry II of England.

阿基坦法国西南部一个历史地区，位于比利牛斯山和加隆河之间，在1137年阿基坦的埃莉诺与国王路易斯七世结婚之后阿基坦公国加入法国，但当她再嫁英国亨利二世后，其归属权便受到争议

There are moments when I look at the smiling , happy faces of my expectant staff and wonder how they will cope when confronted by an outraged housemaster along with an unrepentant and recalcitrant bleached blond teenager in 18 years ' time .

有时候，我看着那些满怀期待的员工微笑，幸福的脸，想着当他们遇到一位愤怒的宿舍管理员和一位不知悔改，叛逆，而且将头发染成白色的18岁少年时，他们会如何处理。