多种整体型可燃毒物对改进型快谱超临界水冷堆中子学特性的影响

建立了装载整体型可燃毒物的SCFR-M点火组件模型,计算分析了不同材料、质量分数的可燃毒物在多种布置方案下的组件中子学参数.综合考虑组件功率畸变、寿期初毒物对反应性的控制能力、寿期末毒物的反应性惩罚等因素,选择合适的整体型可燃毒物布置方案.结论表明稀土氧化物Er2O3以方案4布置在组件中具有较好的中子学性能.     

压水堆棒状燃料组件弥散型可燃毒物燃耗特性研究

长寿期小型压水堆需要更合适的可燃毒物进行反应性控制来延长堆芯寿期,针对这一需要开展了压水堆棒状燃料组件弥散型可燃毒物燃耗特性研究,从可燃毒物的消耗与燃耗过程匹配的角度出发,选择了B、Gd、Ho、Sm、Dy、Er、Gd、Eu作为研究对象,使用基于确定论的组件计算程序Dragon对这些核素进行燃耗特性研究。计算结果表明可燃毒物Eu、Er适合作为候选可燃毒物开展下一步研究。     

可燃毒物布置方式的反应性波动特性研究

不同可燃毒物的布置方式可以控制整个燃耗寿期下的反应性波动并且可以提高燃耗深度。本工作在不同富集度下分析可燃毒物的布置方式对堆芯反应性的影响。并对堆芯k_(eff)在整个燃耗寿期下的变化趋势进行分析。结果表明:1)含可燃毒物B和Gd的堆芯,采用16根可燃毒物棒的布置方式;含可燃毒物Er和Eu的堆芯,采用28根可燃毒物棒的布置方式;含可燃毒物~(231)Pa、~(240)Pu和~(241)Am的堆芯,采用组件燃料棒中均含可燃毒物的布置方式。2)在14%富集度下选用~(240)Pu作为可燃毒物;在40%、70%和97%富集度下选用B作为可燃毒物。     

遗传算法在堆芯燃料管理装载模式优化中的应用

从堆芯燃料管理装载模式 (L P)优化中的非确定多项式 (NP)特征和全局寻优要求 ,探讨了遗传算法在 L P优化中的应用。结合 L P优化和遗传算法特点 ,建立了 L P优化的数学模型的矩阵表示。为了解决组件矩阵的有效性问题 ,对组件矩阵进行基于位置的遗传操作 ;考虑到可燃毒物数目的独立性 ,对可燃毒物矩阵进行随机遗传操作 ;对旋向矩阵进行经典遗传操作。类比旅行商问题 ,完成了 L P优化遗传算法编码和解码。并可与相应的堆物理计算程序构成一个完整的堆芯燃料管理程序。     

反转压水反应堆热工水力特性初步研究

采用CFD软件FLUENT对反转压水反应堆(IPWR:Inverted Pressurized WaterReactor)单个燃料元件及冷却剂通道流场进行了数值模拟计算,分析比较了不同栅格尺寸情况下的热工水力特性.计算结果表明,栅格尺寸对IPWR燃料元件温度及冷却剂流动传热特性有较大影响,为今后IPWR燃料栅元、组件、堆芯设计和热工水力分析提供了初步参考和依据.     

NHR-10堆芯的改进设计

介绍了 NHR- 10组件内钆可燃毒物配置、堆芯燃料组件布置和换料方案的改进设计。通过调整钆可燃毒物根数和质量分数来改善堆芯有效增殖因子 (Keff)随燃耗变化的特性 ,采用堆芯燃料组件非均匀布置来降低堆芯功率峰因子(Fxyz) ,采用 1/ 2换料方案使得每炉换料周期比较接近 ,并给出了改进设计结果。TRANP和 NNGFM程序计算结果表明 :改进设计后 ,Fxyz从 2 .997降到 2 .2 2 1,运行中的最大Keff从 1.0 5 6降到 1.0 37,Keff随燃耗的变化特性得到了很大改善 ,换料周期除第一个周期为 2 2 5 0 d外 ,后面的周期稳定在 175 0 d,更加符合工程需要。     

WIMS-SN程序系统对NHR-10堆物理设计的有效性

组件计算是堆物理计算中的一个重要环节.用WIMS-SN系统计算含可燃毒物组件时,出现比较大的误差,不适宜低温供热堆含可燃毒物组件的计算.文中分析其计算过程,改进了该程序系统,使它可应用于含可燃毒物燃料组件计算.研究发现用WIMS棒束模型计算钆棒栅元归并截面时,使用的能谱是无钆燃料区的能谱,因此会带来较大误差.为了避免这种情况发生,在输运计算中必采用多群多区模型.通过与TPFAP程序校算,二者差别较小,说明该程序系统可以应用于低温供热堆的物理设计.     

NHR-200 含钆可燃毒物棒性能分析

介绍了２００ＭＷ核供热堆（ＮＨＲ－２００）采用含钆可燃毒物燃料棒作为中子吸收体的设计考虑，并根据ＮＨＲ－２００燃料组件的设计参数，采用压水堆核电厂燃料元件稳态分析程序ＦＲＡＰＣＯＮ－２，并考虑到含钆芯块物性变化，对原有ＭＡＴＰＲＯ数据库中相应物性作了修改，按不同含钆量对可燃毒物棒进行稳态工况的性能分析比较。分析结果表明，ＮＨＲ－２００含钆可燃毒物棒能很好地满足堆芯设计的要求，并且有较大的安全裕度。     

新型可燃毒物的混合应用研究

可燃毒物是长寿期小型无可溶硼堆芯全寿期反应性控制的重要手段.可燃毒物的燃耗特性对反应堆全寿期的功率分布具有重要影响,获取与堆芯燃耗匹配性好的新型可燃毒物是目前研究的一个重要方向.本文在单种可燃毒物研究的基础上,考虑对两种可燃毒物进行混合使用.分析结果表明:采用分区混合使用的方式,可使可燃毒物在初始引入负反应性相当的情况...     

基于SIMULATE3程序对压水堆钍-钚燃料反馈性能及钚焚烧效率研究

采用类似于大亚湾900 MW压水堆的堆芯模型,使用燃料组件计算程序 CASMO4E和反应堆稳态分析程序SIMULATE3分别对铀燃料组件、铀钚燃料组件或钍钚燃料组件组成的堆芯的中子学特性进行了研究,分析了组件的燃耗深度、堆芯的平均燃耗、燃料温度系数与燃耗的关系。结果表明,钍钚燃料组件和铀燃料组件组成的堆芯中子特性相似,同时钍钚燃料用于焚烧武器级钚时,具有更高的焚烧效率。     

Markedness and its Interpretation in Language Use

Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.     

Features of Women's language

Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women＇s language from these perspectives： pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women＇s language, more attention should be paid to language use in social context. What＇s more, the linguistic phenomena in a speaking community can be understood more thoroughly.     

低渗透非均质砂岩油藏启动压力梯度研究

理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。     

On Tragic Consciousness In The Works By Ernest Hemingway

As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.     

Achieving Unusual States of Matter Under High Pressure

正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-     

Exchange-Correlation and Electronic Excitation Energies from Pairing Matrix Fluctuations

We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-     

Density Functional Theory for the Response of Periodic Systems to Electric Fields Based on the Vector Potential Approach

正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that     

On the Thermodynamic Limit for Responses to Static Electromagnetic Fields

For molecular systems,the quantum-mechanical treatment of their responses to static electromagnetic fields usually employs a scalar-potential treatment of the electric field and a vector-potential treatment of the magnetic field.Although the potential for each field separately is associated with the choice of an(unphysical)origin,the precise choice of the origin for the electrostatic field has little consequences for the results.This is different for the     

An affordable accurate evaluation of the binding conformations predicted by molecular docking studies in bio-system

Franck-Condon factors bridge the gap between theoretical modeling and experimental observations for molecular electronic spectroscopy and electron transfer.Under the displaced harmonic oscillator approximation,multidimensional Franck-Condon factors are decomposed into a product of many one-dimensional(1D)Franck-Condon(FC)factors,and each 1D-FC factor is associated with one Huang-Rhys factor that determines the leading contribution of     

Call for Papers

<正>"The Journal of Shanghai Normal University:Mathematics"is published by Shanghai Normal University as regular issues of The Journal of Shanghai Normal University each year from 2014 in English.The editors-in-chief of the issues are professors Yuhao Cong and Maoan Han.The Journal of Shanghai Normal University was started in 1958 with