~3Δ、~3Π、~3Σ~＋Ni—CO分子簇的从头算研究

用从头算研究了ｄ空穴位置不同对Ｎｉ—ＣＯ成键机制的影响。结果表明，Ｎｉ—ＣＯ键中σ／π接受作用的相对强弱，取决于Ｎｉ—ＣＯ簇所处的能态。σ空间电子云较π空间电子云弥散，因而Ｎｉ—ＣＯ簇的稳定性与σ空间电子云的排斥密切相关。随着Ｎｉ４ｐσ轨道上电子占据数的增加，Ｎｉ—ＣＯ稳定性减弱。比较了分子簇Ｎｉ—ＣＯ与ＮｉＣＯ分子及ＣＯ／Ｎｉ化学吸附体系之间的性质。     

Stochastic Simulation of Turing Patterns

We investigate the effects of intrinsic noise on Turing pattern formation near the onset of bifurcation from the homogeneous state to Turing pattern in the reaction-diffusion Brusselator. By performing stochastic simulations of the master equation and using Gillespie＇s algorithm, we check the spatiotemporal behaviour influenced by internal noises. We demonstrate that the patterns of occurrence frequency for the reaction and diffusion pro- cesses are also spatially ordered and temporally stable. Turing patterns are found to be robust against intrinsic fluctuations. Sfochastic simulations also reveal that under the influence of intrinsic noises, the onset of Turing instability is advanced in comparison to that predicted deterministically.     

锌卟啉轴向配合物的光谱特性及配位二聚体分子内的能量传递

通过轴向配位作用构造了ZnTPP-H₂(m-py)TPP卟啉二元体系,研究了配位二聚体的可见吸收光谱和荧光发射光谱特性,考察了二聚体分子内的能量传递过程,观察到能量从激发态ZnTPP^*流向H₂(m-py)TPP。作为对比,研究了ZnTPP-py体系的可见吸收光谱和荧光发射光谱。轴向配位的吡啶引起了ZnTPP荧光光谱明显红移,没有分子内的能量转移过程发生。用吸收光谱和荧光光谱方法计算了加合反应的平衡常数,得到了基本一致的结果。     

金、铜金属纳米棒或纳米线的AFM和SERS的研究(英文)

通过电化学氧化法制备具有不同孔径氧化铝模板 ,利用交流电镀的方法在模板中沉积金属 ,再用酸溶解模板可以得到相应尺度的金属纳米线或纳米棒的阵列 .本文利用原子力显微镜和表面增强拉曼技术分别表征了金和铜两种金属纳米线阵列 .研究结果表明 ,作为探针分子的硫氰(SCN )在金属纳米线上的碳氮三键的振动频率随纳米线直径的增大而蓝移 .这一现象可能是因为尺寸效应对纳米线的费米能级造成影响 ,使不同直径的金属纳米线电子结构存在微小的差别 .     

泛Kennard-Stone算法的数据集代表性度量与分块采样策略

在大数据机器学习时代, 选择更具代表性的数据集对于模型的训练和验证尤为重要. Kennard- Stone(KS)算法及其各种变种(泛KS算法)是一大类优异的数据集分割方法, 但其采样比例或采样数的选择仅能依靠经验或根据建模结果事后评判. KS算法依据原始文献的计算复杂度为\mathrm{O}\left(K^{\mathrm{3}}\right), 难以用于超大数据样本量的计算. 本文基于数据集完备性的讨论, 提出泛KS算法的数据集代表性度量, 以简正振动采样的甲烷分子中碳氢键数据特征分布为例展示采样集代表性效果. 简化KS采样过程的筛选算法, 提高算法效率至\mathrm{O}\text{'}\left(K^{\mathrm{2}}\right). 提出将数据集切分成多个子集分别实施KS采样的分块采样策略, 可进一步提高算法效率至\mathrm{O}″\left(K\right). 偏最小二乘回归测试结果表明， 该方法在提高采样效率的同时仍可保障采样集的代表性.     

Analysis of dark soliton generation in the microcavity with mode-interaction

Mode-interaction plays an important role in the dark soliton generation in the microcavity. It is beneficial to the excitation of dark solitons, but also facilitates a variety of dark soliton states. Based on the non-normalized Lugiato-Lefever equation, the evolution of dark soliton in the microcavity with mode-interaction is investigated. By means of mode-interaction, the initial continuous wave(CW) field evolves into a dark soliton gradually, and the spectrum expands from a single mode to a broadband comb. After changing the mode-interaction parameters, the original modes which result in dual circular dark solitons inside the microcavity, are separated from the resonant mode by 2 free spectral ranges(FSR). When the initial field is another feasible pattern of weak white Gaussian noise, the large frequency detuning leads to the amplification of the optical power in the microcavity, and the mode-interaction becomes stronger. Then, multiple dark solitons, which correspond to the spectra with multi-FSR, can be excited by selecting appropriate mode-interaction parameters. In addition, by turning the mode-interaction parameters, the dark soliton number can be regulated, and the comb tooth interval in the spectrum also changes accordingly. Theoretical analysis results are significant for studying the dark soliton in the microcavity with mode-interaction.     

氢吸附于Pt（1000面的吸附体系族模拟和Raman谱性质计算

本文基于金属簇模型和单激发组态相互作用方法。用Ｈ／Ｐｔｎ（ｎ＝５，６）δ＝０，－１）簇模拟了Ｐｔ（１００）电极上不同吸附位的电子跃迁性质，计算结果表明当采用５１４．５ｎｍ入射激发光时，桥位和穴位吸附的电子跃迁偶极矩和振子强度都很小。因而Ｒａｍａｎ信号太弱，不能检测到；只有在高覆盖度下氢顶位吸附，才能检测到Ｒａｍａｎ信号，与实验结果一致。     

苯二聚体的密度泛函和分子力场的理论研究

针对苯二聚体中的六种重要构象的相互作用,对四种新的密度泛函方法(B97-D、BLYP-D3、M06-2X、XYG3)和常用的分子力场(CHARMM、AMBER、MM3、AMOEBA)进行了系统的评测.研究结果不仅突出了这些新型密度泛函方法,特别是XYG3泛函在 描述- 相互作用体系的实用性,同时也为进一步发展适合描述相互作用体系的分子力场奠定了基础.     

六元和五元环芳香化合物在Si(001)-2×1面上的Diels-Alder加成反应——结合能与芳香化合物共振能的相关性

建议了一种能量分解方案用于解释苯与Si（001）-2×1面发生[4+2]加成反应时结合能相当低这一有趣现象,并通过密度泛函簇模型计算证实,这种能量分解方案可以应用于其他的六元和五元环芳香化合物,并揭示了这些芳香化合物与Si（001）-2×1面发生[4+2]加成反应时,其结合能与芳香化合物的共振能有较强的相关性.