化学与化工学科研究进展

化学与化工学科是我院的主体学科之一，其内容主要涉及核化学与核化工、含能材料化学、有机化学与高分子化学、电化学和环境化学与环境工程等领域。核化学与核化工领域主要包括放射化学、氢同位素化学与氚工艺、铀（钚）化学及其与核能释放相关的材料化学。含能材料化学主要涉及炸药的设计、合成、加工号『生能研究。有机化学与高分子化学主要开展激光聚变靶材料的制备、性能检测与应用研究，还包括武器用结构材料的结构与性能研究。电化学主要开展长寿命热电池的应用研究。在环境化学与环境工程领域，主要涉及环境监测与评价、“三废”处理技术以及核设施退役技术的研究与应用。     

振动图象与波动图象的区别和转化

在讨论波动图象与振动图象的区别与转化前，先来看一下波动与振动的区别与联系。     

两维耦合腔系统中的纠缠特性EI北大核心CSCD

研究四个二能级原子与两维耦合腔的相互作用系统,其中每个腔囚禁一个二能级原子,并且原子通过单光子跃迁与腔场发生共振相互作用。利用负本征值度量两子系统间的纠缠,讨论了腔与腔之间的耦合系数变化对原子与原子之间和腔与腔之间纠缠的影响。研究结果表明,随腔与腔之间耦合系数的增大,原子与原子之间纠缠增强,腔与腔之间纠缠减弱。     

实施科学方法教育应处理好七个关系

论述了在中学物理教学中实施科学方法教育需要处理好七个关系:科学方法教育与知识教学的关系;科学方法教育与学生科学素养全面提升的关系;短期目标与长期目标的关系;主要科学方法与次要科学方法的关系;教学目标与教学策略的关系;课堂落实与课外拓展的关系;科学方法教育与中高考的关系.     

关于磁场强度H的进一步讨论

本文首先阐明磁场强度Ｈ与哪些物理量有关，并指明磁化电流分布和介质分布的区别与联系；其次论证了Ｈ与磁化电流分布无关和Ｈ只与传导电流分布有关的条件以及两者的区别与联系．     

浅海中简正波的衰减与群速

本文从均匀浅海的频散方程出发导出了计算简正波衰减与群速的公式,并通过数值例子比较了它们的精度。文中特别讨论了临界简正波的衰减与群速,证明Pekeris浅海中临界简正波的衰减与群速一般小于海底吸收与声速,从而修正了 Kornhauser,Raney,Weston与Tindle关于临界简正波衰减与群速正好等于海底吸收与声速的结论。     

两维耦合腔系统中的纠缠特性

研究四个二能级原子与两维耦合腔的相互作用系统,其中每个腔囚禁一个二能级原子,并且原子通过单光子跃迁与腔场发生共振相互作用。利用负本征值度量两子系统间的纠缠,讨论了腔与腔之间的耦合系数变化对原子与原子之间和腔与腔之间纠缠的影响。研究结果表明,随腔与腔之间耦合系数的增大,原子与原子之间纠缠增强,腔与腔之间纠缠减弱。     

中学物理价值观及其教学

1 问题的提出 物理价值观是指对物理知识与方法、现象与实验、过程与结论等有无价值、价值大小作出判断,进而决定自己相应学习活动或行为的标准和原则.新课改提出"知识与技能、过程与方法、情感态度与价值观"课程三维目标体系,强调物理教学中要重视落实情感、态度与价值观的培养.因此,探讨中学物理价值观的意义与内涵、教学的原则与策略,对提高一线教师的认识和操作水平,优化教学从而落实"价值观"培养,无疑会有很大的帮助.     

颗粒与高频感应热等离子体流的迭代计算

用完全二维自洽模型计算等离子体的速度场与温度场，用颗粒轨迹模型计算颗粒的运动轨迹与加热历程，但在等离子体的连续、动量和能量控制方程中，增加一项由于颗粒直径、运动速度及能焓的变化而引起的源项，计及颗粒的运动与加热对等离子体的速度场与温度场的影响；在颗粒的运动轨迹与加热历程计算中，考虑流体阻力和热泳力对颗粒运动与加热的影响；并在等离子体的速度场与温度场和颗粒的运动与加热之间进行迭代计算。通过对铝颗粒与     

强激光与粒子束

《强激光与粒子束》是中国核学会主办的自然科学技术期刊(ISSN 1001—4322),旨在报导我国激光与粒子束技术领域的基础理论、实验与应用研究的成果和最新进展。内容涉及高功率激光与粒子束的产生、传输及其与物     

Triangular Invariants, Three-Point Functions and Particle Stability on the de Sitter Universe

We study a class of three-point functions on the de Sitter universe and on the asymptotic cone. A blending of geometrical ideas and analytic methods is used to compute some remarkable integrals, on the basis of a generalized star-triangle identity living on the cone and on the complex de Sitter manifold. We discuss an application of the general results to the study of the stability of scalar particles on the de Sitter universe.     

Study of Si and C adatoms and SiC clusters on the silicon surface by the molecular dynamics method

Individual Si and C adatoms, as well as SiC clusters, on a Si surface are simulated by the molecular dynamics method in the course of investigation of the initial stages of formation of a SiC layer on silicon with the help of molecular beam epitaxy. The potential energy surfaces for Si and C adatoms on the (2 × 1) reconstructed Si(001) surface and on the nonreconstructed Si(111) surface, as well as on the Si(111) surface with a SiC cluster, are calculated and analyzed. The values of migration barriers for adatoms on these surfaces are calculated. The effect of the SiC cluster on deformation of the surface region of Si(111) and on the migration of adatoms is investigated. The deep minima observed on the potential energy surfaces immediately above a cluster and at its boundaries can trap diffusing adatoms. The distributions of stresses and strains in the silicon lattice under a cluster on the surface are studied and described.     

小液滴撞击壁面传热特性数值分析

小液滴撞击壁面现象在喷雾冷却等领域都有广泛应用.为研究小液滴(微米)撞击热壁面(非沸腾区)传热过程,建立了二维液滴撞壁瞬态模型,并采用相场方法对小液滴换热过程中对流热通量和导热热通量的大小进行了对比.研究结果表明:液滴撞击壁面初期形成“冷斑”,有利于小液滴与壁面的传热;小液滴撞击壁面过程中热通量峰值存在于三相接触点附近,数量级在105—106 W/m²;小液滴撞击壁面过程中受壁面浸润性和液滴尺寸对传导热通量的影响较为显著,而速度和液滴尺寸对对流热通量的影响较为显著;大多数情况下,小液滴撞击壁面传导热通量数量级在103—105 W/m²,对流热通量数量级在104—106 W/m²,对流热通量大于传导热通量,在整个换热过程中占据主导地位.     

B、N、S掺杂石墨烯表面质子吸附的第一性原理研究

表面吸附是石墨烯中质子(H~+)输运的基础步骤.本文基于第一性原理计算研究了B、N、S掺杂对石墨烯表面H~+吸附行为的影响.结果表明,B、N、S掺杂对石墨烯的晶体结构、内聚能及电子性质有重要影响,且影响程度与掺杂元素的性质密切相关,进而导致对石墨烯表面H~+吸附行为产生不同程度的影响.从吸附能的观点看,N、B、S掺杂对石墨烯表面H~+的吸附有利.研究结果对石墨烯在氢贮存、氢同位素分离、燃料电池等领域的应用具有重要的指导意义.     

重离子碰撞中的同位旋效应

根据近年来利用同位旋相关输运理论在中能重离子碰撞同位旋效应研究方面的成果 ,并结合国际上在该问题上的进展 ,综合介绍和分析了中能重离子碰撞中的多重碎裂、原子核阻止和前平衡发射中子-质子比的同位旋效应及其随入射道条件:入射能量、碰撞参数、碰撞系统的质量 ,特别是随中子-质子比的演化过程.讨论了利用以上物理观测量在提取同位旋非对称核物质状态方程知识方面的可能性 ,并对其发展进行了展望. Based on the achievements for the intermediate energy heavy ion collision in our recent work and the progresses in the world, the isospin effects and the dependence of the entrance channel conditions on them in the intermediate energy heavy ion collisions were introduced, analysed and commended. From the calculation results by using isospin dependence quantum molecular dynamics, it is clear to see that the nuclear stopping power strongly depends on the in medium isospin dependence...     

C---H bond activation of formate on clean and K-covered Ru(001): a theoretical study

An extended Hückel (EH) study is performed on the clusters representing a formate adsorbed on Ru(001) and on in order to investigate the effect of potassium on the selectivity of decomposition of formate on Ru(001). The adsorption geometry and the VSIP (valence state ionization potential) values of EH parameters are determined from ab initio calculations on small clusters. The EH calculation reproduces well the site preference of formate on each surface suggested from experiments. The C---H bond of formate, which is our focus in this study, is calculated to be almost the same on the two surfaces when the molecular plane of formate is perpendicular to the surface; but when the plane is tilted from the surface normal and thus the C---H bond approaches the surface, the C---H bond is weakened to a much higher extent on clean Ru(001) than on K-covered Ru(001). This is in good agreement with the experimental result that the presence of potassium changes the reaction pathway of the decomposition of formate on Ru(001) by suppressing C---H bond cleavage.     

Dependence on substrate topography of growth of nanosized dendritic structures in an electron-beam-induced deposition process

Nanometer-sized W-dendrites are fabricated on Al₂O₃ substrates with an electron-beam-induced deposition process. Dependence of growth of nanodendrite on surface topography is investigated with transmission electron microscopy. It is confirmed that the nanodendrite grows on convex surfaces but not around a hole on a substrate. These are attributed to different distribution of charges on surfaces with different topographies during electron beam irradiation when charges are produced on the surface due to emission of second electrons. The charges accumulate on convex surface and do not distribute around a hole. Therefore, the nanodendrite grows on the former and not on the latter.     

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设计了EAST 4.6GHz低杂波器件的一系列主动水冷冷却结构,阐述了直波导、波导弯头、天线单元的水冷结构设计,并使用有限元模拟软件ANSYS计算了这些部件的发热和对流冷却,计算并展示了部件上的温度分布二环结构变形。通过计算,优化直波导单面水冷结构为双面水冷。计算结果表明,立弯波导弯头的水冷结构明显好于侧弯弯头。原天线单元前端温度分布集中,热应力很大,不符合实验要求。优化后的天线单元前端的温升和热变形可以达到LHCD实验要求。     

Interaction of water with stepped Co(0001): how is it different from flat Co(0001)?

The adsorption and dissociation of water monomer and dimer on stepped Co(0001) surface were studied by means of first-principles calculations. Present results indicate that the adsorption strength of water is greatly enhanced by the presence of step, while the activity of water monomer dissociation does not exhibit a noticeable improvement. Nevertheless, water dimer partial dissociation on stepped Co(0001) is more active than on flat Co(0001), and the promotion of oxygen atom on O–H bond cleavage of H₂O is more prominent on stepped surface than on flat Co(0001). The findings reveal the importance of low coordinated surface atoms on metallic catalysts and the vital role of surface rippling on water dissociation. Together with previous reports, the activity of water dissociation on cobalt-based catalytic surfaces depends dominantly on O-containing species like oxygen atom, H₂O or hydroxyl.     

锯齿型石墨烯纳米带的能带研究

运用π电子紧束缚模型,具体研究了锯齿型石墨烯纳米带(ZGNRs)的边界结构对能带,特别是费米面附近的导带和价带电子的影响.计算了七种不同边界结构的ZGNRs的能带色散关系及费米面附近价带电子在原胞中各原子上的分布情况.计算结果表明:两边界都无悬挂原子的NN-ZGNRs,只有一边界有悬挂原子的DN-ZGNRs,两边界都有五边形环的SPP-ZGNRs和ASPP-ZGNRs为金属性.两边界都有悬挂原子的DD-ZGNRs,一边界为五边形环另一边界无悬挂原子的PN-ZGNRs和一边界为五边形环另一边界有悬挂原子的P 关键词： 锯齿型石墨烯纳米带 紧束缚模型 电子密度分布 缺陷结构