Development of spin‐orbit coupling for stochastic configuration interaction techniques

To perform spin‐orbit coupling calculations on atoms and molecules, good zeroth‐order wavefunctions are necessary. Here, we present the software development of the Monte Carlo Configuration Interaction (MCCI) method, to enable calculation of such properties, where MCCI iteratively constructs a multireference wavefunction using a stochastic procedure. In this initial work, we aim to establish the efficacy of this technique in predicting the splitting of otherwise degenerate energy levels on a range of atoms and small diatomic molecules. It is hoped that this work will subsequently act as a gateway toward using this method to investigate singlet‐triplet interactions in larger multireference molecules. We show that MCCI can generate very good results using highly compact wavefunctions compared to other techniques, with no prior knowledge of important orbitals. Higher‐order relativistic effects are neglected and spin‐orbit coupling effects are incorporated using first‐order degenerate perturbation theory with the Breit‐Pauli Hamiltonian and effective nuclear charges in the one‐electron operator. Results are obtained and presented for B, C, O, F, Si, S, and Cl atoms and OH, CN, NO, and C₂ diatomic radicals including spin‐orbit coupling constants and the relative splitting of the lowest energy degenerate state for each species. Convergence of MCCI to the full configuration interaction result is demonstrated on the multireference problem of stretched OH. We also present results from the singlet‐triplet interaction between the and both the and states of the O₂ molecule. © 2017 Wiley Periodicals, Inc.     

Synthesis and insecticidal evaluation of tetrahydroimidazo[1,2-a]pyridin-5(1H)-one derivatives

A series of novel tetrahydroimidazo[1,2-a]pyridine-5(1H)-one derivatives containing a electronegative pharmacophore(=CNO₂) were synthesized via practical aza-ene reaction and characterized by ¹H NMR, ¹³C NMR, ¹⁹F NMR and HRMS. Preliminary bioassays showed that some of the target compounds exhibited good insecticidal activity against brown planthopper(Nilaparvata lugens) and cowpea aphids(Aphis craccivora) at 500 mg L^-1. Among them, compound 11h was active against brown planthopper at 100 mg L^-1. The insecticidal activities varied significantly depending on the types and patterns of the substituents, which provided guidance for further investigation on structure modifications.     

Relative stereochemistries of the ether rings and sugar moieties in durinskiol A

Durinskiol A (1) is a long carbon-chain polyol compound with a molecular weight of 2128 mu isolated from the symbiotic dinoflagellate Durinskia sp. The relative stereochemistries of ether rings and sugar moieties in 1 were established based on 2D-NMR analysis and molecular modeling studies. Conformational analysis of the 6,5,6-bis-spiroacetal ring in 1 was also examined by using ab initio methods.     

The braid groups of the projective plane and the Fadell–Neuwirth short exact sequence

We study the pure braid groups of the real projective plane , and in particular the possible splitting of the Fadell–Neuwirth short exact sequence , where n ≥ 2 and m ≥ 1, and p _* is the homomorphism which corresponds geometrically to forgetting the last m strings. This problem is equivalent to that of the existence of a section for the associated fibration of configuration spaces. Van Buskirk proved (1966, Trans. Am. Math. Soc., 122:81–97) that p and p _* admit a section if n = 2 and m = 1. Our main result in this paper is to prove that there is no section if n ≥ 3. As a corollary, it follows that n = 2 and m = 1 are the only values for which a section exists. As part of the proof, we derive a presentation of : this appears to be the first time that such a presentation has been given in the literature.      

聚芳醚酮在溶液中的分子构象与分子极化

经从头计算,得到4,4'-二氟苯酮二面角为44°,MES₃二面角为51°;用UV光谱法研究了单分散齐聚物在H₂SO₄中的分子构象与极化,结果表明:H₂SO₄使碳基质子化是产生极化的主要因素之一,由此产生的新吸收峰在λ=400nm左右;极化作用产生的平面构象经重叠后在λ=500nm左右产生另一新的吸收峰.由质子化模型并考虑组态相互作用的计算结果与文献一致.证明了聚芳醚酮高聚物在H₂SO₄中,于400nm左右处产生的峰(UV)为羰基极化的结果,指明在H₂SO₄中测其分子量时应按羰基含量校正.     

聚合物表面刷子模型的形态结构及动力学特性

阐述了稀溶液及聚合物溶液中高分子链及其刷子模型在外力和流场作用下的结构形态及动力学特性。单分子链在外力作用下经历从嗽叭形到花杂形的变形,最后完全解缠而伸展,单分散性刷子模型中的单链节密度在沿刷子高度方向上呈抛物线形分布。在多分散性刷子模型中分子链的结构形态呈多样性变化,溶液中球形界面刷子之间的作用力与吸附的平衡状态有关,电解质溶液中的刷子及带电刷子在溶液中的电中性分布文章也有详细阐述。     

锌金属硫蛋白预防甲基汞对细胞膜损伤作用的实验研究

不同剂量的Ｚｎ可以诱导小鼠肝脏产生ＺｎＭＴ,随着实验组Ｚｎ剂量的增加,肝脏内ＺｎＭＴ的含量也相应增加,呈剂量效应增加（ｒ＝０．９９６）。ＺｎＭＴ具有保护膜构象、膜ＳＨ基、拮抗ＭｅＨｇ对膜流动性及膜通透性的损伤作用。本实验结果为ＺｎＭＴ预防甲基汞中毒提供了科学依据,同时显示了诱导ＺｎＭＴ的锌剂量要适当,过高则有毒性作用。     

Syntheses and Crystal Structures of Functionalized Tetramethyl Resorcinarenes

Tetramethyl resorcinarene, which was obtained by acidic condensation of resorcinol with paraacetoaldehyde, was chemically modified to the functionalized O-acyl, O-tosyl and O-acetate derivatives by corresponding acylation, p-toluenesulfonylation and alkylation reactions. The single crystal structures of these functionalized resorcinarenes and the complex of tetramethyl resorcinarene with 2,2'-bipyridine were determined by X-ray diffraction method. All these resorcinarenes adopt the all-cis configuration with four methyl groups stretching to the down rim and form 1D or 2D structures through H-bonds.     

The Structure of Typical Clusters in Large Sparse Random Configurations

The initial purpose of this work is to provide a probabilistic explanation of recent results on a version of Smoluchowski’s coagulation equations in which the number of aggregations is limited. The latter models the deterministic evolution of concentrations of particles in a medium where particles coalesce pairwise as time passes and each particle can only perform a given number of aggregations. Under appropriate assumptions, the concentrations of particles converge as time tends to infinity to some measure which bears a striking resemblance with the distribution of the total population of a Galton-Watson process started from two ancestors. Roughly speaking, the configuration model is a stochastic construction which aims at producing a typical graph on a set of vertices with pre-described degrees. Specifically, one attaches to each vertex a certain number of stubs, and then join pairwise the stubs uniformly at random to create edges between vertices. In this work, we use the configuration model as the stochastic counterpart of Smoluchowski’s coagulation equations with limited aggregations. We establish a hydrodynamical type limit theorem for the empirical measure of the shapes of clusters in the configuration model when the number of vertices tends to ∞. The limit is given in terms of the distribution of a Galton-Watson process started with two ancestors.