氧化铝/氮化硅双层膜晶硅钝化的开尔文探针力显微镜研究

对晶体硅(c-Si)太阳能电池而言, 氧化铝(AlOx)是一种广泛使用的钝化材料, 因为它具有优异的沉积保形性和良好的钝化质量. 为了确保AlOx发挥其良好的钝化效果, 在沉积后退火并氢化处理是必不可少的. 通过在AlOx薄膜上沉积氢化氮化硅(SiNx:H)来实现氢化, 利用开尔文探针力显微镜研究了在不同热处理和氢化作用下, AlOx/SiNx:H双层薄膜功函数的变化, 并基于沉积薄膜所含氢与固定电荷展开了讨论. 发现钝化质量和功函数之间有相关性, 影响因素包括薄膜厚度、氢化与热处理顺序.     

Wave packet dynamics of nonlinear Gazeau–Klauder coherent states of a position-dependent mass system in a Coulomb-like potential

AD = 1 position-dependent mass approach to constructing nonlinear quantum states for a modified Coulomb potential is used to generate Gazeau–Klauder coherent states. It appears that their energy eigenvalues are scaled down by the quantum number and the nonlinearity coefficient. We study the basic properties of these states, which are found to be undefined on the whole complex plane, and some details of their revival structure are discussed.     

Addendum to “On the Riesz potential operator of variable order from variable exponent Morrey space to variable exponent Campanato space”, Math Meth Appl Sci. 2020; 1–8

In the paper mentioned in the title, it is proved the boundedness of the Riesz potential operator of variable order α(x) from variable exponent Morrey space to variable exponent Campanato space, under certain assumptions on the variable exponents p(x) and λ(x) of the Morrey space. Assumptions on the exponents were different depending on whether $\frac{\alpha (x)p(x)?n+\lambda (x)}{p(x)}$ takes or not the critical values 0 or 1. In this note, we improve those results by unifying all the cases and covering the whole range $0?\frac{\alpha (x)p(x)?n+\lambda (x)}{p(x)}?1$. We also provide a correction to some minor technicality in the proof of Theorem 2 in the aforementioned paper.     

阳离子交换皂石黏土在基质辅助激光解吸电离飞行时间质谱分析中的应用

将一种人工合成的无机聚合物——蒙脱石皂石黏土（smectite，Sm）应用于基质辅助激光解吸电离飞行时间质谱分析（matrix-assisted laser desorption/ionization time of flight mass spectrometry, MALDI-TOF-MS），以检测糖类化合物。 将传统的有机基质2，4，6-三羟基苯乙酮（trihydroxyacetophenone, THAP）与阳离子交换后的皂石黏土混合制备成新型复合基质，应用于糖类化合物的检测。通过比较不同的制样方法，测定不同分子直径的糖类化合物，发现由于受复合基质晶面间距的限制，只有小分子糖类化合物能进入晶面间隙充分接触有机基质并被离子化，从而实现对小分子糖类化合物的选择性检测。     

Ab initio structure and vibration-rotation dynamics of germylene,GeH2

Accurate structure and potential energy surface of germylene, GeH₂, in its ground electronic state ¹A₁ were determined from ab initio calculations using the coupled-cluster approach in conjunction with the correlation-consistent basis sets up to sextuple-zeta quality. The Born-Oppenheimer equilibrium structural parameters for the ¹A₁ state are estimated to be r_e(GeH) = 1.5793 Å and ∠_e(HGeH) = 91.19^∘. The term value T_e for the lowest excited electronic state ã³B₁ of GeH₂ is predicted to be 9140 cm^–1. The vibration-rotation energy levels for the ¹A₁ state of the ⁷⁴GeH₂, ⁷⁴GeD₂, ⁷²GeH₂, and ⁷⁰GeH₂ isotopologues were determined using a variational approach and compared with the experimental data. The role of the core-electron correlation, higher-order valence-electron correlation, scalar relativistic, spin-orbit, and adiabatic effects for prediction of the structure and vibration-rotation dynamics of the GeH₂ molecule is discussed. © 2019 Wiley Periodicals, Inc.     

Fabrication of Pre-tilted Vertical Alignment Layers for High-Speed Liquid Crystal Display Using Bi-functional Photoreactive Monomers

Abstract

To enable recent 3D and moving picture applications, liquid crystal displays (LCD) must exhibit fast response and wide viewing angle characteristics. Pre-tilted vertical alignment layers for high-speed LCD were fabricated using bi-functional photoreactive monomers. The monomers can be confined to the polyimide layer and photo-polymerized by UV exposure under voltage. Response characteristics of photo-controlled alignment films according to the structure were investigated. Vertical alignment properties were evaluated using a polarizing optical microscope, and electro-optical characteristics were compared through the voltage-transmittance curve and response time measurement. Faster response speed could be obtained by using photoreactive monomers having a long alkyl chain.     

Magnesium-Based Clusters as Building Blocks of Electrolytes in Lithium-Ion Batteries

Superhalogens, owing to their large electron affinity (EA, exceeding those of any halogen atom), play an essential role in physical chemistry as well as new material design. They have applications in hydrogen storage and lithium-ion batteries. Owing to the unique geometries and electronic features of magnesium-based clusters, their potential to form a new class of lithium salts has been investigated here theoretically. The idea is assessed by conducting ab initio computations on Li⁺/Mg_nF_2n+1-2mO_m⁻ compounds (n=2, 3; m=0-3) and analyzing their performance as potential Li-ion battery electrolytes. The Mg₃F₇⁻ cluster, with large electron binding energy (EA of 7.93 eV), has been proven to serve as a building block for lithium salts. It is shown that, apart from high electronic stability, the new superhalogen-based electrolytes exhibit a set of desirable properties, including a large band gap, high electrolyte stability window, easy mobility of the Li⁺, and favorable insensitivity to water.     

Transition probabilities of the X1Σ+, A1Π, B1Δ, C1Σ+, and D1Π states of the AlO+ cation

ABSTRACT

This study computes the potential energy curves of the X¹Σ⁺, A¹Π, B¹Δ, C¹Σ⁺, and D¹Π states of AlO⁺ cation and the transition dipole moments between them. The orders of the rotationless radiative lifetimes are 10–100?μs for the A¹Π state, 1–1000?ms for the B¹Δ state, 10?ns for the first well and 100?ns for the second well of the C¹Σ⁺ state, and 1?μs for the D¹Π state. Emissions of the B¹Δ–A¹Π and D¹Π–C¹Σ⁺ systems are so weak that they are hardly measured via spectroscopy, the emissions of the C¹Σ⁺–X¹Σ⁺, C¹Σ⁺–A¹Π, and D¹Π–X¹Σ⁺ systems are so strong that they can be detected readily, and emissions of the A¹Π–X¹Σ⁺ and D¹Π–A¹Π systems can be observed through spectroscopy only by a significant effort. There is a strong great similarity between spontaneous emissions of the A¹Π–X¹Σ⁺ system of the AlO⁺ cation and the A²Π–X²Σ⁺ system of the AlO radical. The emissions of the A²Π–X²Σ⁺ system of the AlO radical have been measured in outer space Therefore, it is highly possible that the emissions of the A¹Π–X¹Σ⁺ system of the AlO⁺ cation can be detected in the astrophysical media.     

Revealing and comparing different excited-state intramolecular proton transfer processes for 3-(4-dimethylamino-phenyl)-1-(4-fluoro-2-hydroxy-phenyl)-propenone and 3-(4-dimethylamino-phenyl)-1-(4-fluoro-2-hydroxy-phenyl)-3-hydroxy-propenon

Two novel 2′-hydroxychalcone derivatives (i.e., M1 and M2) are explored in this work. We mainly focus on investigating the effects of photoexcitation on hydrogen bonds and on the excited-state intramolecular proton transfer (ESIPT) process. On the basis of calculations of electrostatic potential surface and intramolecular interactions, we verify the formation of hydrogen bond O1 H2···O3 in both S₀ and S₁ states. Exploring the ultraviolet–visible spectra in the liquid phase, our simulated results reappear in the experimental phenomenon. Analyzing molecular geometry and infrared stretching vibrational spectra, we confirm O1 H2···O3 is strengthened for both M1 and M2 in the S₁ state. We further confirm that charge redistribution facilitates ESIPT tendency. Constructing potential energy curves, we find the ultrafast ESIPT behavior for M1, which is because of the deficiency of side hydroxyl moiety comparing with M2. This work makes a reasonable affiliation of the ESIPT mechanism for M1 and M2. We wish this paper could facilitate understanding these two novel systems and promote their applications.     

微波瑞利散射法测定空气电火花激波等离子体射流的时变电子密度

大气压空气电火花激波等离子体射流的电子密度在亚微秒时间尺度上瞬变,其电子密度的测定很难.基于微波瑞利散射原理,本文测量了空气电火花冲击波流注放电等离子体射流的时变电子密度.实验结果表明:测量系统的标定参数A为1.04 × 105 V·Ω·m–2;空气流注放电等离子体射流的电子密度与等离子体射流的半径和长度有关,结合高速放电影像展示的等离子体射流的等效半径和等效长度,测定的电子密度在1020 m–3的量级,且随时间先快速增长至峰值再成指数衰减.此外,本文还探讨了等离子体射流的不同等效尺度对测定结果的影响;分析结果表明,采用时变等效半径和时变等效长度的计算结果最有效,且第1个快速波峰是由光电离的电离波导致的.