Ab initio calculations on the ground and excited states of InI

Potential energy curves (PECs) of the ground and the low-lying excited states of the InI molecule are computed using the internally contracted multireference singles and doubles configuration interaction with the Davidson correction (ic-MR-CISD + Q) method based on the relativistic effective core potentials (RECPs). The spectroscopic constants are obtained, including the excitation energy (T _e), the equilibrium bond distance (R _e), the dipole moment (μ_e) and the vibrational constants (ω_e and ω_e). Finally, we predict the transition dipole moments, the radiative lifetimes, and the Franc-Condon factors for the transitions of A³Π₀+ ? X¹Σ₀ ⁺ and B³Π^l ? X¹Σ₀ ⁺,. The results reveal that A³Π₀+ and B³Π_l are long-lived states with the lifetimes being of the order of microseconds.     

冷冻电镜技术——2017年诺贝尔化学奖介绍

介绍了2017年诺贝尔化学奖的3位获得者在冷冻电镜领域的主要贡献，同时介绍了冷冻电镜技术的用途、一般工作流程和其局限性，以及中国学者在冷冻电镜技术应用研究中的贡献。     

Palladium-Catalyzed Enantioselective Alkenylation of Enelactams Using a Relay Heck Strategy

In this report, a palladium-catalyzed redox-relay Heck process to access optically active alkenylated α,β-unsaturated lactams is described. Under mild reaction conditions, electron-deficient alkenyl triflates and electron-rich alkenyl iodonium salts undergo enantioselective and site-selective coupling with enelactams to deliver the products in high yields and excellent enantioselectivities. Furthermore, the products allow facile access to natural products such as (+)-calvine and (+)-2-epicalvine in addition to the bioactive molecule aza-goniothalamin.     

Ideal Free Distribution in Two Patches

In this paper, the formats of Julia sets for a class of nonlinear complex dynamic systems with variable coefficients were studied under certain conditions. For the complex dynamic systems in piecewise cases, we proposed some methods to control the forms of their Julia sets and stable domains analytically. What’s more, we illustrated that our methods worked well by computational simulations. Our work provides a better understanding about how to control the Julia sets of certain complex dynamic systems.     

Synthesis and properties of sulfur‐contained poly(silylene arylacetylene)s

Poly(silylene arylacetylene) (PSA) is a kind of poly(arylacetylene) silicon‐containing resins with excellent heat resistance and good mechanical performances. In this article, the sulfur atom is introduced into the main chain of the PSA molecule to obtain a sulfur‐containing poly(silylene arylacetylene), named S‐PSA. By Williamson and Sonogashira reactions, bis(4‐ethynylphenyl)sulfide and bis(4‐ethynylphenyl)sulfone were synthesized. Thereafter, through Grignard reagent way, the poly(silylene ethynylene phenylene sulfide phenylene ethynylene) (PSESE) and poly(silylene ethynylene phenylene sulfone phenylene ethynylene) (PSESO₂E) were synthesized from bis(4‐ethynylphenyl)sulfide, bis(4‐ethynylphenyl)sulfone, and methylphenyl dichlorosilane. Poly(silylene ethynylene phenylene sulfoxide phenylene ethynylene) (PSESOE) was synthesized by the oxidation of PSESE. The structures and properties of these resins were characterized and the mechanical properties of the T300 reinforced composites were tested. The results show that the novel S‐PSA resins have excellent heat resistance and good mechanical properties, and could be used as resin matrices for high‐performance composites in high‐tech fields. © 2019 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2019, 57, 2324–2332     

Validated liquid chromatography–tandem mass spectrometry method for quantification of ticagrelor and its active metabolite in human plasma

A rapid, simple and sensitive LC–MS/MS method was established and validated for simultaneous quantification of ticagrelor and its active metabolite AR‐C124910XX in human plasma. After plasma samples were deproteinized with acetonitrile, the post‐treatment samples were chromatographed on a Dikma C₁₈ column interfaced with a triple quadrupole tandem mass spectrometer. Electrospray negative ionization mode and multiple reaction monitoring were adopted to assay ticagrelor and AR‐C124910XX. Acetonitrile and 5 mΜ ammonium acetate was used as the mobile phase with a gradient elution at a flow rate of 0.5 mL/min. The method was linear in the range of 0.781–800 ng/mL for both ticagrelor and AR‐C124910XX with a correlation coefficient ≥0.994. The intra‐ and inter‐day precisions were within 12.61% in terms of relative standard deviation and the accuracy was within ±7.88% in terms of relative error. The LC–MS/MS method was fully validated for its sensitivity, selectivity, stability, matrix effect and recovery. This convenient and specific LC–MS/MS method was successfully applied to the pharmacokinetic study of ticagrelor and AR‐C124910XX in healthy volunteers after an oral dose of 90 mg ticagrelor.     

Implications on cosmic ray injection and propagation parameters from Voyager/ACE/AMS-02 nucleus data

We study the propagation and injection models of cosmic rays using the latest measurements of the boron-to-carbon ratio and fluxes of protons, helium, carbon, and oxygen nuclei by the Alpha Magnetic Spectrometer and the Advanced Composition Explorer at top of the Earth, and the Voyager spacecraft outside the heliosphere. The Advanced Composition Explorer(ACE) data during the same time interval of the AMS-02 data are extracted to minimize the complexity of the solar modulation effect. We find that the cosmic ray nucleus data favor a modified version of the diffusion-reacceleration scenario of the propagation. The diffusion coefficient is, however, required to increase moderately with decreasing rigidity at low energies, which has interesting implications on the particle and plasma interaction in the Milky Way. We further find that the low rigidity( a few GV) injection spectra are different for different compositions. The injection spectra are softer for lighter nuclei. These results are expected to be helpful in understanding the acceleration process of cosmic rays.     

Ag@CH3NH3PbI3等离激元效应增强钙钛矿太阳能电池性能的数值研究

由于银纳米粒子结构的表面等离激元共振特性对有机无机卤化物钙钛矿的新型太阳能电池性能有一定影响,利用comsol mutiphysics多物理场仿真软件对Ag@CH3 NH3 PbI3纳米粒子等离激元效应增强钙钛矿太阳能薄膜电池性能进行研究,对粒子半径和粒子间距对于能量的影响进行了计算;对光敏层能量增强的机理进行了解释;并对电场分布进行了详细说明.依据实验数据,给出优化后的银纳米粒子阵列和钙钛矿光敏层的厚度以及强度,为实验制备高效稳定的钙钛矿太阳能电池提供理论指导.