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21.
Yu-Ting Tseng Dr. Wei-Min Ching Prof. Wen-Feng Liaw Prof. Tsai-Te Lu 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(29):11917-11921
Continued efforts are made for the utilization of CO2 as a C1 feedstock for regeneration of valuable chemicals and fuels. Mechanistic study of molecular (electro-/photo-)catalysts disclosed that initial step for CO2 activation involves either nucleophilic insertion or direct reduction of CO2. In this study, nucleophilic activation of CO2 by complex [(NO)2Fe(μ-MePyr)2Fe(NO)2]2− ( 2 , MePyr=3-methylpyrazolate) results in the formation of CO2-captured complex [(NO)2Fe(MePyrCO2)]− ( 2-CO2 , MePyrCO2=3-methyl-pyrazole-1-carboxylate). Single-crystal structure, spectroscopic, reactivity, and computational study unravels 2-CO2 as a unique intermediate for reductive transformation of CO2 promoted by Ca2+. Moreover, sequential reaction of 2 with CO2, Ca(OTf)2, and KC8 established a synthetic cycle, 2 → 2-CO2 → [(NO)2Fe(μ-MePyr)2Fe(NO)2] ( 1 ) → 2 , for selective conversion of CO2 into oxalate. Presumably, characterization of the unprecedented intermediate 2-CO2 may open an avenue for systematic evaluation of the effects of alternative Lewis acids on reduction of CO2. 相似文献
22.
23.
S. K. Liaw S. Wang C. S. Shin N. K. Chen K. C. Hsu A. Manshina Y. Tver’yanovich C.-F. Su L. K. Wang 《Laser Physics》2010,20(7):1608-1611
A single-longitudinal-mode selection is realized in a linear-cavity fiber laser construction using a loop-back optical circulator
and a partial reflectance fiber Bragg grating as the cavity ends. At 1551 nm wavelength, the measured signal-to-noise-ratio
is 56 dB and with a line width less than 1 MHz obtained using multiple subring cavities as mode filters. The pumping efficiency
is 10% improved by recycling the residual pump power to gain medium. 相似文献
24.
25.
Liaw Shien-Kuei Ho Keang-Po Chen Yuan-Kuang Lee Chien-Chung 《Optical and Quantum Electronics》1999,31(1):77-83
A reconfigurable wavelength-division-multiplexing (WDM) add/drop multiplexer (WADM) is constructed using optical switches (OSWS) and fibre Bragg gratings (FBGs). Selected one or two channel(s) can be added/dropped at the same multiplexer by properly controlling the optical switch pair and fibre Bragg grating arrangement. Afour-channel system is experimentally demonstrated for a data rate of 2.5 Gb s–1 and a single-mode fibre (SMF) distance of 100km. A negligible maximum power penalty of only 0.3dB is observed when compared with back-to-back transmission. 相似文献
26.
Liu CW Hung CM Haia HC Liaw BJ Liaw LS Tsai YF Wang JC 《Chemical communications (Cambridge, England)》2003,(8):976-977
The novel halide-centered Ag(I)8 cubic clusters containing diethyl diselenophosphato ligands are prepared and their solid state structures, a discrete unit or a one-dimensional chain, are dictated by the counter anions. 相似文献
27.
Thomas Harmening Constanze M. Fehse Rainer Pöttgen 《Journal of solid state chemistry》2011,184(12):3303-3309
The silicides ScTSi (T=Fe, Co, Ni, Cu, Ru, Rh, Pd, Ir, Pt) were synthesized by arc-melting and characterized by X-ray powder diffraction. The structures of ScCoSi, ScRuSi, ScPdSi, and ScIrSi were refined from single crystal diffractometer data. These silicides crystallize with the TiNiSi type, space group Pnma. No systematic influences of the 45Sc isotropic magnetic shift and nuclear electric quadrupolar coupling parameters on various structural distortion parameters calculated from the crystal structure data can be detected. 45Sc MAS-NMR data suggest systematic trends in the local electronic structure probed by the scandium atoms: both the electric field gradients and the isotropic magnetic shifts relative to a 0.2 M aqueous Sc(NO3)3 solution decrease with increasing valence electron concentration and within each T group the isotropic magnetic shift decreases monotonically with increasing atomic number. The 45Sc nuclear electric quadrupolar coupling constants are generally well reproduced by quantum mechanical electric field gradient calculations using the WIEN2k code. 相似文献
28.
We design an inclination-sensing system based on a fiber-ring laser integrated fiber-Bragg grating (FBG) whose peak wavelength is changed by the axial strain. By replacing a conventional broadband light source with the fiber-ring laser, we raise the sensing power to 3.1 dBm, the peak-to-noise ratio to 65.31 dB, and reduce the 3-dB bandwidth to 0.06 nm. Thus, the sensitivity and resolution of the proposed system are greatly improved. By using an FBG integrated with a pendulum ball used as a sensor head, the resolution of the angular inclination could reach 0.015 nm per degree. These specifications are qualified for the general practice of the pendulum-sensing system. 相似文献
29.
Wong WW Vak D Singh TB Ren S Yan C Jones DJ Liaw II Lamb RN Holmes AB 《Organic letters》2010,12(21):5000-5003
A new class of self-assembling hexa-peri-hexbenzocoronene (HBC)-fullerene hybrid materials has been synthesized and characterized. Photoluminescence experiments indicate that energy transfer processes can be tuned in these donor-acceptor systems by varying the length and nature of the linker group. In preliminary device testing, ambipolar charge transport behavior is observed in organic field effect transistors, while single active component organic photovoltaic devices consisting of these materials achieved a maximum external quantum efficiency of 30%. 相似文献
30.
Cheng‐Hung Chang Kun‐Li Wang Jyh‐Chiang Jiang Der‐Jang Liaw Kueir‐Rarn Lee Juin‐Yih Lai Kuo Yuan Chiu Yuhlong Oliver Su 《Journal of polymer science. Part A, Polymer chemistry》2010,48(24):5659-5669
A series of highly organosoluble polyamides with high modulus having propeller‐shaped triarylamine were synthesized using aromatic diacid chlorides by low‐temperature solution polycondensation. The polyamide films had strong, tough, flexible, and amorphous properties. These polymers revealed electrochromic characteristics both in the visible range and near‐infrared (NIR) region, with a color change from pale yellowish at its neutral state to green and blue at its oxidized state at applied potentials ranging from 0.00 to 1.35 V. Cyclic voltammetry (CV) of the polymer films cast onto an indium tin oxide (ITO)‐coated glass substrate exhibited two reversible redox couples at potentials of 0.80–0.87 V and 1.19–1.25 V, respectively, vs. Ag/Ag+ in acetonitrile solution. From the combination of the experimental and computational study, we proposed an oxidation mechanism based on molecular orbital (MO) theory, which well explains the CV experimental result. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2010 相似文献