meso-四(4-甲氧基-3磺酸基苯)卟啉与环糊精超分子体系的研究

采用极谱法、紫外可见光谱法及荧光光谱法研究了水溶性卟啉T(4-Mop)PS4与α-CD、-βCD、γ-CD、Hp-β-CD及SBE--βCD 5种环糊精的相互作用,结果表明T(4-Mop)PS4分别与这5种环糊精形成了T(4-Mop)PS4-CD s超分子体系。此外,本研究还采用极谱法、紫外可见光谱法及荧光光谱法测定了T(4-Mop)PS4-CD s超分子体系的包结常数和包结比,比较了T(4-Mop)PS4与5种环糊精的包结能力,并由此推测了包结机理,为T(4-Mop)PS4卟啉、环糊精的进一步应用提供了理论信息。     

漂移管工作温度对离子迁移率谱的影响

离子迁移率、反应物离子的种类和产量与漂移管工作温度有很大的关系。本研究在不同温度下进行了离子迁移率实验,结果表明,离子迁移率随温度的升高而增大,而提高工作温度可以减少水分子对产物离子的影响,有利于改善系统检测的分辨率;选择合适漂移管工作温度,能有效地增加反应物离子的产量,从而提高系统检测的灵敏度和选择性。     

A Novel 3D Na(I) Coordination Polymer Constructed by 3,5-Bis(4'-Carboxy-Phenyl)-1,2,4-Triazole: Synthesis,Crystal Structure,and Photocatalytic Property

Crystallography Reports - A novel 3D metal coordination polymer, {[Na4(µ2-H2O)(DMF)2(BCT)2]?DMF}n (I) (DMF = N,N-dimethylformamide, H2BCT =...     

Theoretical study on the catalytic properties of single-atom catalyst stabilised on silicon-doped graphene sheets

ABSTRACT

The stable configurations, electronic structures and catalytic activities of single-atom metal catalyst anchored silicon-doped graphene sheets (3Si-graphene-M, M?=?Ni and Pd) are investigated by using density functional theory calculations. Firstly, the adsorption stability and electronic property of different gas reactants (O₂, CO, 2CO, CO/O₂) on 3Si-graphene-M substrates are comparably analysed. It is found that the coadsorption of O₂/CO or 2CO molecules is more stable than that of the isolated O₂ or CO molecule. Meanwhile, the adsorbed species on 3Si-graphene-Ni sheet are more stable than those on the 3Si-graphene-Pd sheet. Secondly, the possible CO oxidation reactions on the 3Si-graphene-M are investigated through Eley–Rideal (ER), Langmuir–Hinshelwood (LH) and new termolecular Eley–Rideal (TER) mechanisms. Compared with the LH and TER mechanisms, the interaction between 2CO and O₂ molecules (O₂?+?CO → CO₃, CO₃?+?CO → 2CO₂) through ER reactions (< 0.2?eV) are an energetically more favourable. These results provide important reference for understanding the catalytic mechanism for CO oxidation on graphene-based catalyst.     

Porphyrin-like porous nanomaterials as drug delivery systems for ibuprofen drug

In recent years, nanomaterial-based drug delivery carriers have become some of the most attractive to be studied. The purpose of this study is to investigate the interaction of C60 fullerene, carbon nanotube and graphene having porphyrin-like FeN4 clusters with a non-steroidal anti-inflammatory drug (ibuprofen) by means of the density functional theory. Results showed that the graphene with FeN4 clusters could remarkably increase the tendency of graphene for adsorption of ibuprofen drug. Also, our ultraviolet–visible results show that the electronic spectra of the complexes exhibit a blue shift toward lower wavelengths (higher energies). It was found that Ibp/FeN4-graphene had high chemical reactivity, which was important for binding of the drug onto the target site. In order to go further and gain insight into the binding features of considered systems with ibuprofen drug, the Atoms in Molecules analysis was performed. Our results determine the electrostatic features of the Ibp/FeN4-graphene bonding. Consequently, the results demonstrated that the FeN4-graphene could be used as potential carriers for the delivery of ibuprofen drug.     

Numerical approach for the evolution of spin-boson systems and its application to the Buck–Sukumar model

We study the evolution properties of spin-boson systems by a systematic numerical iteration approach, which performs well in the whole coupling regime. This approach evaluates a set of coefficients in the formal expression of the time-dependent Schr?dinger equation by expanding the initial state in Fock space. This set of coefficients is unique for the spin-boson Hamiltonian studied, allowing one to calculate the time evolution from different initial states. To complement our numerical calculations, we apply the method to the Buck–Sukumar model. We find that when the ground-state energy of the model is unbounded and no ground state exists in a certain parameter space, the time evolution of the physical quantities is naturally unstable.     

改变激发环境调控Ho3+离子的上转换发光特性

稀土掺杂上转换发光材料的发光特性不仅依赖于基质材料本身,而且与其激发条件密切相关.本文主要是以Ho^3+离子为研究对象,在NaYF4和LiYF4这两种不同的基质中,研究其在不同激发条件下的上转换发光特性.通过共聚焦显微光谱测试系统,对比Ho^3+离子在NaYF4和LiYF4微米晶体中的发光特性.实验结果发现:Ho^3+离子在这两种不同基质中均展现出较强的荧光发射.然而,当激发功率增加时,在单颗粒个LiYF4微米晶体中,当激发功率增加时,Ho^3+离子则发射出较强绿光及微弱的红光,红绿比变化并不明显,其蓝光发射强度也相对较弱.当激发这两种微米粉末晶体时,结果发现:Ho^3+离子均发射较强的绿光发射并伴有微弱红光发射,两种晶体中的发射特性极其相似.由此可见,在常规测试条件下,一些特殊发光现象是很难被观测到的.同时,通过对其光谱特性的分析,对Ho^3+离子的发光机理进行了研究.     

Determination of structure parameters in strong-field ionization models of atoms

The Ammosov–Delone–Krainov (ADK) and Perelomov–Popov–Terent’ev (PPT) ionization models were widely used in strong-field physics and attosecond science due to their many attractive advantages such as simpler analytical formula, less computational demands, and satisfied accuracy of ionization rate. Based on the density-functional theory, we systematically determine accurate structure parameters of 25 atoms, 24 positive ions and 13 negative ions and tabulate for future applications. The wave function with correct asymptotic behavior is obtained by solving the time-independent Schrödinger equation with B-spline basis sets and the accurate structure parameters are extracted from this wave function in the asymptotic region. The accuracies of structure parameters are carefully examined by comparing the ionization probabilities (or yields) calculated by PPT and ADK models with those of solving the three-dimensional time-dependent Schrödinger equation and the experimental data.     

超强频率梳激光场驱动下多光子共振谐波辐射的相位突变研究

本文从理论上研究了在双色频率梳激光场驱动下多光子谐波辐射光谱中的相位突变现象。我们利用Floquet理论非微扰地模拟了频率梳激光场与原子分子等量子系统的相互作用过程。谐波辐射信号是多光子偶极跃迁相干叠加的结果,通过调节频率梳激光场间的相对相位,可以相干地控制谐波辐射信号的强度。通过对谐波信号进行傅里叶变换,可以提取不同跃迁路径的相对相位信息。我们通过改变频率梳组激光场的强度和频率组分实现多光子跃迁频率,让其跨越共振跃迁频率时,谐波相位会发生突变。从而可以观测超强激光场驱动下量子系统共振跃迁频率的斯塔克能移。     

基于简单MOPA结构实现3.08 kW全光纤窄线宽线偏振激光输出

基于简单的主振荡功率放大结构,演示了一种高功率窄线宽线性偏振全光纤激光器,其最大输出功率为3.08 kW,3 dB线宽为0.2 nm。在整个功率缩放过程中,偏振消光比约为94%,光束质量M 2约为1.4。这是国内外首次实现3 kW全保偏光纤激光输出,与基于相位调制的窄线宽激光器相比,该激光器可实现近似的线宽,同时具有受激布里渊散射阈值高、系统结构简单、成本低等特点。