NLO‐X (X = I–III): New Gaussian basis sets for prediction of linear and nonlinear electric properties

New adjusted Gaussian basis sets are proposed for first and second rows elements (H, B, C, N, O, F, Si, P, S, and Cl) with the purpose of calculating linear and mainly nonlinear optical (L–NLO) properties for molecules. These basis sets are new generation of Thakkar‐DZ basis sets, which were recontracted and augmented with diffuse and polarization extrabasis functions. Atomic energy and polarizability were used as reference data for fitting the basis sets, which were further applied for prediction of L–NLO properties of diatomic, H₂, N₂, F₂, Cl₂, BH, BF, BCl, HF, HCl, CO, CS, SiO, PN, and polyatomic, CH₄, SiH₄, H₂O, H₂S, NH₃, PH₃, OCS, NNO, and HCN molecules. The results are satisfactory for all electric properties tested; dipole moment (µ), polarizability (α), and first hyperpolarizability (β), with an affordable computational cost. Three new basis sets are presented and called as NLO‐I (ADZP), NLO‐II (DZP), and NLO‐III (VDZP). The NLO‐III is the best choice to predict L–NLO properties of large molecular systems, because it presents a balance between computational cost and accuracy. The average errors for β at B3LYP/NLO‐III level were of 8% for diatomic molecules and 14% for polyatomic molecules that are within the experimental uncertainty. © 2014 Wiley Periodicals, Inc.     

星载近红外高光谱CO2遥感进展

在应用需求的拉动和高光谱技术发展的驱动下,利用被动式星载近红外高分辨率光谱仪探测大气CO₂分子柱含量已成为一个相当活跃的研究领域。本文介绍了卫星遥感CO₂在科学和社会发展方面的基本需求,分析了被动遥感CO₂的优势和不足;对国际上最新的以美国OCO-2(2014年7月发射)和日本GOSAT(2009年1月发射)为代表的专项CO₂遥感任务进行了综述,包括仪器指标、观测模式和定标模式等方面;着重对OCO-2定标精度需求和多种在轨定标方式进行了阐述;从应用和数据处理角度,简要比较了光栅和傅里叶干涉探测技术探测CO₂的主要特点;最后对定量反演原理进行了概述,并对这一领域的未来发展进行了展望。     

高阶整函数系数线性微分方程解的增长性

主要研究了高阶整函数系数线性微分方程f(n) An-1f(n-1) … A1f′ A0f=0的解的增长性,我们证明了如果σ(Aj)>1,σ(Aj),j=1,…,n-1都不是整数,且0＜σ(A0)≤(1)(2)和每个Aj的所有零点都位于与它的亏格有关的角域内,那么方程的每个解f(≠)0具有无穷增长级,并得到其超级的一些估计.     

Non‐degenerate second‐order scattering and difference combination bands in infrared‐pump/anti‐Stokes resonance Raman‐probe experiments

Non‐degenerate second‐order scattering due to interaction of infrared and ultraviolet pulses is observed in picosecond infrared‐pump/anti‐Stokes Raman‐probe experiments under electronic resonance conditions. We detected resonance hyper‐Rayleigh scattering at the sum frequency of the pulses as well as the corresponding frequency‐down‐shifted resonance hyper‐Raman lines. Nearly coinciding resonance hyper‐Raman and one‐photon resonance Raman spectra indicate conditions of A‐term resonance Raman scattering. Second‐order scattering is distinguished from transient anti‐Stokes Raman scattering of v = 1 to v = 0 transitions and v = 1 to v′ = 1 combination transitions by taking into account their different spectral and temporal behaviour. Separating these processes is essential for a proper analysis of transient vibrational populations. Copyright © 2007 John Wiley & Sons, Ltd.