三种烟草品种基因组DNA傅里叶红外光谱研究

利用傅里叶红外光谱(FTIR)研究三种烟草品种DNA的差异,旨在对烟草品种进行亲缘关系分析和品种鉴定。研究结果显示,三种烟草品种DNA红外光谱较为相似,均有四个明显的特征峰,1 103 cm~(-1)是DNA磷酸二酯键的对称伸缩振动,1 236 cm~(-1)是DNA磷酸二酯键的非对称伸缩振动,1 400 cm~(-1)是DNA糖苷键的伸缩振动,I 622 cm~(-1)是DNA中是胞嘧啶C4—C5=C6的环伸缩振动。通过平滑、标准化处理、二阶求导、提取主成分和系统聚类分析建立了DNA FTIR光谱数据聚类分析模型。使用该模型对三个烟草品种进行鉴定,鉴定正确率为100%。使用该模型对三个烟草品种进行亲缘关系分析,云烟87与K326聚为一类,距离系数为0.003,DNA相似度为99.7%,红大单独聚为一类。聚类正确率达100%。该项研究为烟草品种鉴定及遗传育种提供了参考。     

Overcoming Statistical Complexity: Selective Coordination of Three Different Metal Ions to a Ligand with Three Different Coordination Sites

In general, it is difficult to selectively introduce different metal ions at specific positions of a cluster‐like structure. This is mainly due to statistical problems as well as the reversibility of the formation of coordination bonds. To overcome this statistical problem, we used a carefully designed ligand, H₆L, which can accommodate three different kinds of metal ions in three types of coordination sites. The complex [LNiZn₂La]³⁺, which contains three different metals, was quantitatively obtained by a stepwise procedure, but different products were obtained when the metal ions were added in a different order. However, equilibration studies indicated that this complex was almost solely formed among 54 (=3×3×₃H₂) possible products upon heating; the formation efficiency (ca. 100 %) was significantly higher than the statistical probability (2.47 %). Such carefully designed ligands should be useful for the synthesis multimetallic systems, which are of interest because of the interplay between the different metals.     

Deterministic remote state preparation of arbitrary three-qubit state through noisy cluster-GHZ channel

We propose a novel scheme for remote state preparation of an arbitrary three-qubit state with unit success probability, utilizing a nine-qubit cluster-GHZ state without introducing auxiliary qubits. Furthermore, we proceed to investigate the effects of different quantum noises (e.g., amplitude-damping, phase-damping, bit-flip and phase-flip noises) on the systems. The fidelity results of three-qubit target state are presented, which are usually used to illustrate how close the output state is to the target state. To compare the different effects between the four common types of quantum noises, the fidelities under one specific identical target state are also calculated and discussed. It is found that the fidelity of the phase-flip noisy channel drops the fastest through the four types of noisy channels, while the fidelity is found to always maintain at 1 in bit-flip noisy channel.     

Cn,CnH and their anions: Quest for linearity with n≤8 even versus odd,and beyond

Using the concept of quasi-molecule (“tile”) and the database of quasi-molecules embedded on a parent molecule, it is discussed whether the latter can attain linear form or otherwise. Besides anew accurate optimization of all tiles (quasi-triatomics) at various levels of ab initio theory and basis-sets, the nature of the predicted stationary points for the title parent molecules is probed through a priori calculations here too reported. Also discussed is the common rule that even- $n$ ${\text{C}}_n{\text{H}}^{-}$ anions are linear while odd-numbered ones tend to have nonlinear isomers. The reported quasi-molecule approach is general, and allow the prediction of linearity or otherwise of the parent systems prior to calculations on them. When based on an extension of the bisection method (Varandas, Int. J. Quantum Chem. 2023 , 123, e27036.), it is easy to use even for large parent molecules, as illustrated for neutral and anionic carbon clusters with $n\ge 9$.     

两个基于混酸配体的十二核锰配合物的合成和结构

应用乙酸锰、高锰酸钾和丙酸(或氯乙酸)混酸体系合成,得到了2个基于Mn12O12核心的十二核锰配合物,分子式分别为[Mn12O12(O2CMe)8(O2CEt)8(H2O)4].2H2O(1)和[Mn12O12(O2CMe)12(O2CCl3)4(H2O)4].4MeCO2H.8H2O(2)。X射线单晶衍射分析表明配合物1结晶于四方晶系I4空间群,晶胞参数为:a=b=2.650 5(3)nm,c=1.349 7(3)nm,Z=4;配合物2结晶于四方晶系I41/acd空间群,晶胞参数为:a=b=2.7067(1)nm,c=2.5880(2)nm,Z=8。这2个配合物结构都具备Mn12O12核心,与其他经典Mn12明星分子的核心相似。中心的Mn4O4立方核通过μ3-氧桥被非共面的Mn8O8环聚集在一起,而16个η2-μ-混合羧酸以不同方向在外围充当连接桥,同时提供了酸性环境。文中还分析了混酸体系的pKa值对配合物结构形成的影响。     

Ground‐State and Excitation Spectra of a Strongly Correlated Lattice by the Coupled Cluster Method

The coupled cluster method is applied to a strongly correlated lattice Hamiltonian, and the coupled cluster linear response method is extended to the calculation of electronic spectra by finding an approximation to a resolvent operator which describes the spectral response of the coupled cluster solution to excitation operators. In this spectral coupled cluster method, the ground and excited states appear as resonances in the spectra, and the resolvent can be iteratively improved in selected spectral regions. The method is applied to a MnO₂ plane model which corresponds to previous experimental works.