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41.
42.
Dang Huu Phuc Ha Thanh Tung Van-Cuong Nguyen My Hanh Nguyen Thi 《Molecules (Basel, Switzerland)》2021,26(10)
In this study, TiO2/CdS/CdxCu1−xSe, TiO2/CdS/CdxMn1−xSe, and TiO2/CdS/CdxAg2−2xSe thin films were synthesized by chemical bath deposition for the fabrication of photoanode in quantum-dot-sensitized solar cells. As a result, the structural properties of the thin films have been studied by X-ray diffraction, which confirmed the zinc Blende structure in the samples. The optical films were researched by their experimental absorption spectra with different doping concentrations. Those results were combined with the Tauc correlation to estimate the absorption density, the band gap energy, valence band and conduction band positions, steepness parameter, and electron–phonon interaction. Furthermore, the electrical features, electrochemical impedance spectrum and photocurrent density curves were carried out. The result was used to explain the enhancing performance efficiency. 相似文献
43.
Cellulose - The paper is a review on the extraction processes of cellulosic fibers from flax and hemp. The two lignocellulosic crops have a long history of use by humans for extraction of the bast... 相似文献
44.
Mechanistic Insights into the Interface‐Directed Transformation of Thiols into Disulfides and Molecular Hydrogen by Visible‐Light Irradiation of Quantum Dots
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Xu‐Bing Li Zhi‐Jun Li Yu‐Ji Gao Qing‐Yuan Meng Shan Yu Prof. Dr. Richard G. Weiss Prof. Dr. Chen‐Ho Tung Prof. Dr. Li‐Zhu Wu 《Angewandte Chemie (International ed. in English)》2014,53(8):2085-2089
Quantum dots (QDs) offer new and versatile ways to harvest light energy. However, there are few examples involving the utilization of QDs in organic synthesis. Visible‐light irradiation of CdSe QDs was found to result in virtually quantitative coupling of a variety of thiols to give disulfides and H2 without the need for sacrificial reagents or external oxidants. The addition of small amounts of nickel(II) salts dramatically improved the efficiency and conversion through facilitating the formation of hydrogen atoms, thereby leading to faster regeneration of the ground‐state QDs. Mechanistic studies reveal that the coupling reaction occurs on the QD surfaces rather than in solution and offer a blueprint for how these QDs may be used in other photocatalytic applications. Because no sacrificial agent or oxidant is necessary and the catalyst is reusable, this method may be useful for the formation of disulfide bonds in proteins as well as in other systems sensitive to the presence of oxidants. 相似文献
45.
Ya-Hang Wu Prof. Dr. Hongyan Xiao Prof. Dr. Bin Chen Prof. Dr. Richard G. Weiss Prof. Dr. Yu-Zhe Chen Prof. Dr. Chen-Ho Tung Prof. Dr. Li-Zhu Wu 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(25):10259-10264
Three rigid and structurally simple heterocyclic stilbene derivatives, (E)-3H,3′H-[1,1′-biisobenzofuranylidene]-3,3′-dione, (E)-3-(3-oxobenzo[c] thiophen-1(3H)-ylidene)isobenzofuran-1(3H)-one, and (E)-3H,3′H-[1,1′-bibenzo[c] thiophenylidene]-3,3′-dione, are found to fluoresce in their neat solid phases, from upper (S2) and lowest (S1) singlet excited states, even at room temperature in air. Photophysical studies, single-crystal structures, and theoretical calculations indicate that large energy gaps between S2 and S1 states (T2 and T1 states) as well as an abundance of intra and intermolecular hydrogen bonds suppress internal conversions of the upper excited states in the solids and make possible the fluorescence from S2 excited states (phosphorescence from T2 excited states). These results, including unprecedented fluorescence quantum yields (2.3–9.6 %) from the S2 states in the neat solids, establish a unique molecular skeleton for achieving multi-colored emissions from upper excited states by “suppressing” Kasha's rule. 相似文献
46.
Xiao-Qin Liu Ke Zhang Prof. Jian-Feng Gao Prof. Yu-Zhe Chen Prof. Chen-Ho Tung Prof. Li-Zhu Wu 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(52):23662-23666
Hypoxia is a parameter related to many diseases. Ratiometric hypoxia probes often rely on a combination of an O2-insensitive fluorophore and an O2-sensitive phosphor in a polymer matrix, which require high cost and multi-step synthesis of transition metal complexes. The two-chromophore hypoxia probes encounter unfavorable energy transfer processes and different stabilities of the chromophores. Reported herein is a pure organic ratiometric hypoxia nanoprobe, assembled by a monochromophore, naphthalimide ureidopyrimidinone (BrNpA-UPy), bridged by a bis-UPy-functionalized benzyl skeleton. The joint factors of quadruple hydrogen bonding, the rigid backbone of UPy, and bromine substitution of the naphthalimide derivative facilitate bright phosphorescence (ΦP=7.7 %, τP=3.2 ms) and fluorescence of the resultant nanoparticles (SNPs) at room temperature, which enable accurate, ratiometric, sensitive oxygen detection (Ksv=189.6 kPa−1) in aqueous solution as well as in living HeLa cells. 相似文献
47.
Son Tung Ngo Trung Hai Nguyen Nguyen Thanh Tung Pham Cam Nam Khanh B. Vu Van V. Vu 《Journal of computational chemistry》2020,41(7):611-618
Determination of the ligand-binding affinity is an extremely interesting problem. Normally, the free energy perturbation (FEP) method provides an appropriate result. However, it is of great interest to improve the accuracy and precision of this method. In this context, temperature replica exchange molecular dynamics implementation of the FEP computational approach, which we call replica exchange free energy perturbation (REP) was proposed. In particular, during REP simulations, the system can easily escape from being trapped in local minima by exchanging configurations with high temperatures, resulting in significant improvement in the accuracy and precision of protein–ligand binding affinity calculations. The distribution of the decoupling free energy was enlarged, and its mean values were decreased. This results in changes in the magnitude of the calculated binding free energies as well as in alteration in the binding mechanism. Moreover, the REP correlation coefficient with respect to experiment ( RREP = 0.85 ± 0.15 ) is significantly boosted in comparison with the FEP one ( RFEP = 0.64 ± 0.30 ). Furthermore, the root-mean-square error (RMSE) of REP is also smaller than FEP, RMSEREP = 4.28 ± 0.69 versus RMSEFEP = 5.80 ± 1.11 kcal/mol, respectively. © 2019 Wiley Periodicals, Inc. 相似文献
48.
Rui Guo Xin Zhang Tong Li Qianli Li David A. Ruiz Liu Leo Liu Chen-Ho Tung Lingbing Kong 《Chemical science》2022,13(8):2303
A cationic terminal iminoborane [Mes*N B ← IPr2Me2][AlBr4] (3+[AlBr4]−) (Mes* = 2,4,6-tri-tert-butylphenyl and IPr2Me2 = 1,3-diisopropyl-4,5-dimethylimidazol-2-ylidene) has been synthesized and characterized. The employment of an aryl group and N-heterocyclic carbene (NHC) ligand enables 3+[AlBr4]− to exhibit both B-centered Lewis acidity and BN multiple bond reactivities, thus allowing for the construction of tri-coordinate boron cations 5+–12+. More importantly, initial reactions involving coordination, addition, and [2 + 3] cycloadditions have been observed for the cationic iminoborane, demonstrating the potential to build numerous organoboron species via several synthetic routes.An NHC-stabilized aryliminoboryl cation exhibits both boron-centered Lewis acidity and multiple bond reactivity and could be utilized as an effective synthon for unusual cationic boron species. 相似文献
49.
Son Tung Dang Ernst Arne Meese John Christian Morud Stein Tore Johansen 《国际流体数值方法杂志》2019,91(9):419-447
In this paper, we introduce numerical methods that can simulate complex multiphase flows. The finite volume method, applying Cartesian cut-cell is used in the computational domain, containing fluid and solid, to conserve mass and momentum. With this method, flows in and around any geometry can be simulated without complex and time consuming meshing. For the fluid region, which involves liquid and gas, the ghost fluid method is employed to handle the stiffness of the interface discontinuity problem. The interaction between each phase is treated simply by wall function models or jump conditions of pressure, velocity and shear stress at the interface. The sharp interface method “coupled level set (LS) and volume of fluid (VOF)” is used to represent the interface between the two fluid phases. This approach will combine some advantages of both interface tracking/capturing methods, such as the excellent mass conservation from the VOF method and good accuracy of interface normal computation from the LS function. The first coupled LS and VOF will be generated to reconstruct the interface between solid and the other materials. The second will represent the interface between liquid and gas. 相似文献
50.
Ming‐Yi Chen Jian‐Xun Wang Kung‐Tung Chen Bi‐Zhou Wen Wei‐Chieh Lin Chiing‐Chang Chen 《中国化学会会志》2012,59(2):170-175
Calcium carbide residue (CCR) was investigated in transesterification reaction of triglycerides to determine its viability as a solid catalyst for biodiesel synthesis. Literature survey showed that CCR has never been studied as a solid catalyst in the transesterification of triglyceride. The scope of the study includes the effects of CCR calcination temperature, calcination time, the alcohol/oil molar ratio, the catalyst amount (wt % of oil) and the reaction time. The relationship between chemical composition and catalytic activity of waste cement was also investigated. These CCR catalysts, thermally activated at 600 °C, can give rise to fatty acid methyl esters (FAME) purity higher than 99.5%, after 3 h of reaction, when oil/methanol molar ratio of 1/12 and 1 wt % of the catalyst were employed. Application of CCR as catalyst for biodiesel production in this study may not only provide a cost‐effective and environment friendly way of recycling CCR waste but also reduce hopefully the cost of biodiesel production. 相似文献