Effect of Multiple Scattering in the Lidar Measurement of Tropospheric Aerosol Extinction Profiles

This paper describes the lidar inversion of the tropospheric aerosol extinction profiles under the influence of multiple-scattering effects for various elevation angles of lidar detection. A single-scattering lidar equation is employed to analyze lidar signals with multiple-scattering contributions that are calculated by the Monte Carlo method for given atmospheric conditions. We calculate errors in the optical thickness from the results with and without multiple-scattering effects. It is found that the errors vary in a range of 2#x2013;18#x0025; according to the optical thickness variation of 0.19#x2013;3.8. The dependence of the error on the field-of-view angle of the lidar observation is also discussed.     

Precision synthesis of regioregular poly(3‐hexylthiophene) with low dispersity using a zincate complex catalyzed by nickel with the ligand of 1,2‐bis(dicyclohexylphosphino)ethane

Regioregular poly(3‐hexylthiophene) (P3HT) has been a commonly used p‐type semiconducting material for solution processable organic electronics. To establish a living system of “Negishi‐type catalyst‐transfer polycondensation (NCTP)” using zincate complex as a synthetic method for well‐defined P3HT having predictable molecular weight (MW) and low dispersity (?), the ligands of Ni catalyst were optimized. As a result, a ligand of 1,2‐bis(dicyclohexylphosphino)ethane produced P3HTs with highly controlled number average MWs (1650–32,800) and very low ? values (1.03–1.17). The polymerization results were strongly influenced by steric hindrance based on the factors of cone angle and bite angle of Ni catalysts, and/or electron‐donating ability of phosphine ligands. In addition, we succeeded in the two‐stage polymerization of P3HT and the synthesis of P3HT‐b‐poly(3‐octadecylthiophene), the latter of which is the first demonstration by NCTP using zincate complex. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014 , 52, 2287–2296     

Inspection of cracks using laser-induced ultrasound with shadow method: Modeling and validation

A numerical model based on the finite element method (FEM) is developed for crack inspection using laser-induced ultrasonic waves with the shadow method. Before the simulation, the numerical code is verified by comparing the directivity patterns of ultrasonic waves with the experiment. The use of thermo-elastically generated ultrasonic waves for crack detection and evaluation with the shadow method is investigated by simulation. The simulation is validated by comparing with the experiment.     

Selective COSY‐J‐resolved‐HMBC,a new method for improving sensitivity of cross peaks of methine proton signals attached to a methyl group

Improved pulse sequences for measuring long‐range C‐H coupling constants (ⁿJ_C‐H), named selective COSY‐J‐resolved HMBC‐1 and ?2, have been developed. In the spin systems, such as ‐CH_C‐CH_A(CH₃)‐CH_B‐, a methine proton H_A splits into a multiplet owing to several vicinal couplings with protons, resulting in attenuation of its cross‐peak intensity. Therefore, the measurements of ⁿJ_C‐H with H_A are generally difficult in the J‐resolved HMBC or selective J‐resolved HMBC spectrum. With the aim of accurate measurements of ⁿJ_C‐H in such a spin system, we have developed new pulse sequences, which transfer the magnetization of a methyl group to its adjacent methine proton. The proposed pulse sequences successfully enable to enhance the sensitivity of H_A cross peak in comparison with the selective J‐resolved HMBC pulse sequence. Copyright © 2012 John Wiley & Sons, Ltd.     

Pressure-tuning resonance between the vibron and the libron in crystalline methylene halides

Abstract

The high-pressure Raman spectra of crystalline methylene halides (CH2Cl2, CH2ClI, CH2Br2, CH2BrI and CH2I2) have been measured to study the resonance phenomena between the vibron and the libron. The pressure-tuning resonances were observed around 4 3 and 2 5 kbar for CH2Br2 and CH2BrI, and their vibron-libron coupling constants were determined to be 10.3 and 4 cm^?1, respectively. The same resonance was not observed for CH2ClI; the libron just passes through the vibron mode without mutual interaction. From these results, including more CH2Cl2 and CH2I2, we investigate the dominant factors to determine the possibility of observing pressure-tuning of the vibron-libron resonance and present a systematic explanation of new phenomenon in methylene halides.     

Design and synthesis of new cationic water‐soluble pyrene containing dendrons for DNA sensory applications

A series of new water‐soluble cationic pyrene‐dendron derivatives, G1 , G2 , and G3, was successfully synthesized and characterized. These new dendrons were designed with the quaternized amino moieties at the periphery of the dendrons for DNA detection and functionalized with pyrene as a fluorescent probe. The electrostatic interactions between the plasmid DNA (pDNA) and cationic charged dendrons in an aqueous solution resulted in a change in the photophysical properties of pyrene, which could be shown in the UV‐vis and fluorescence spectra. Pyrene dendrons showed a high and rapid fluorescence response upon the addition of pDNA, which was strongly dependent on the size and hydrophobicity of the dendrons. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012     

Synthesis,characterization, and application to polymer solar cells of polythiophene derivatives with ester‐ or ketone‐substituted phenyl side groups

Four polythiophene derivatives including regiorandom polymers P1 , P2 , and P3 and a regioregular polymer P4 , containing a phenyl side chain with electron‐withdrawing carbonyl groups such as an ester and a ketone at the 3‐position of the thiophene ring, were synthesized by Stille coupling reaction. Bulk‐heterojunction polymer solar cells (PSCs) based on these polymers as p‐type semiconductors and [6,6]‐phenyl‐C₆₁‐butyric acid methyl ester (PCBM) were fabricated, and their photovoltaic performances were evaluated for the first time. The PSC devices based on the regioregular polymer P4 :PCBM = 1:2 (w/w) exhibited a high‐open‐circuit voltage (V_oc) of 0.943 V because of the low‐lying highest occupied molecular orbit energy level of P4 . The short π–π stacking distance (0.355 nm) in the parallel direction to the substrate and “face‐on” rich orientation were observed by the grazing incidence wide‐angle X‐ray scattering experiment, which might reflect higher J_sc and FF values of the P4 :[6,6]‐phenyl‐C₇₁‐butyric acid methyl ester (PC₇₁BM) PSC device than others. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2015 , 53, 875–887     

Selective J‐resolved‐HMQC‐1 and ‐2, new methods for measuring proton–proton coupling constants in strongly coupled spin systems

Efficient pulse sequences for measuring ¹H–¹H coupling constants (J_HH) in strongly coupled spin systems, named selective J‐resolved‐HMQC‐1 and ‐2, have been developed. In the strongly coupled spin systems such as ‐CH₂‐CH_A(OH)‐CH_B(OH)‐CH₂‐, measurements of ³J_HAHB are generally difficult owing to the complicated splitting caused by the adjacent CH₂ protons. For easier and accurate measurements of ³J_HAHB in such a spin system, a selective excitation pulse is incorporated into the J‐resolved HMQC pulse sequence. In the proposed methods, only two strongly coupled protons, H_A and H_B which are excited by a selective pulse, are observed as J‐resolved HMQC signals. The cross peaks of H_A and H_B appear as doublets owing to ³J_HAHB along the F₁ dimension in the selective J‐resolved HMQC‐1 and ‐2 experiments. The efficiency of the proposed pulse sequences has been demonstrated in application to the stereochemical studies of the complicated natural product, monazomycin. Copyright © 2011 John Wiley & Sons, Ltd.