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111.
Dr. Hong Wang Jia Jia Prof. Pengfei Song Dr. Qiang Wang Dr. Debao Li Prof. Shixiong Min Dr. Chenxi Qian Dr. Lu Wang Young Feng Li Chun Ma Prof. Tom Wu Prof. Jiayin Yuan Prof. Markus Antonietti Prof. Geoffrey A. Ozin 《Angewandte Chemie (International ed. in English)》2017,56(27):7847-7852
Herein we introduce a straightforward, low cost, scalable, and technologically relevant method to manufacture an all-carbon, electroactive, nitrogen-doped nanoporous-carbon/carbon-nanotube composite membrane, dubbed “HNCM/CNT”. The membrane is demonstrated to function as a binder-free, high-performance gas diffusion electrode for the electrocatalytic reduction of CO2 to formate. The Faradaic efficiency (FE) for the production of formate is 81 %. Furthermore, the robust structural and electrochemical properties of the membrane endow it with excellent long-term stability. 相似文献
112.
Considering the diffusion reaction at solid interfaces, the ignition temperature of compounds fabricated by self-propagating high-temperature synthesis (SHS) is modelled with the help of size-dependent activation energy. As reactant size decreases, ignition temperature also decreases. This is because of increased contact areas between the reactants and the lowered diffusion barrier, both of which must be calculated specifically for reactants in nanoscale. The model predictions and experimental results are consistent for some metallic compounds. 相似文献
113.
In the calibration of the optical trap stiffness, it is found that there appears an attenuating oscillation as an oscillatory disturbance added to the trapped bead movement, when the scanner is driven by a triangular wave input.An equivalent oscillator model is put forward to explain the mechanism of the oscillatory disturbance. Both the measurements and calculations show that the attenuating oscillation comes from the oscillation of the scanner and the triangular wave drive causes this additional oscillation of the scanner. Furthermore, the analysis indicates that the oscillatory disturbance will become stronger, when the stiffness of the trap increases or the natural frequency of the scanner decreases. We adopt another driving way, i.e. a sinusoidal wave input is used instead of the triangular wave input. Our experiment has verified that in this case the oscillatory disturbance is eliminated completely. 相似文献
114.
《Solid State Ionics》2006,177(17-18):1501-1507
High-quality crystalline MSn2 (M = Cr and Co) thin films have been successfully fabricated by reactive pulsed laser deposition. The physical and electrochemical properties of the as-deposited thin films have been investigated by scanning electron microscopy (SEM), X-ray diffraction (XRD), galvanostatic cycling and cyclic voltammetry (CV). XRD measurement indicates that the as-deposited thin films prepared at 400 °C consisted mainly of MSn2 (M = Cr and Co) with a small quantity of metal tin. The specific reversible capacities of CrSn2 and CoSn2 thin film electrodes are found to be 467 mA h/g and 465 mA h/g, respectively. A mechanism involving an irreversible decomposition of MSn2 (M = Cr and Co) and a classical alloying process of Sn is proposed. MSn2 (M = Cr and Co) as the starting anode materials for conversion to the Li–Sn alloy can improve its electrochemical performance with high reversible capacity and good stable cycle. 相似文献
115.
Hui Zeng Yao Wen Lei Yin Ruiqing Cheng Hao Wang Chuansheng Liu Jun He 《Frontiers of Physics》2023,18(5):53603
Two-dimensional (2D) transition metal dichalcogenides (TMDs) with fascinating electronic energy band structures, rich valley physical properties and strong spin–orbit coupling have attracted tremendous interest, and show great potential in electronic, optoelectronic, spintronic and valleytronic fields. Stacking 2D TMDs have provided unprecedented opportunities for constructing artificial functional structures. Due to the low cost, high yield and industrial compatibility, chemical vapor deposition (CVD) is regarded as one of the most promising growth strategies to obtain high-quality and large-area 2D TMDs and heterostructures. Here, state-of-the-art strategies for preparing TMDs details of growth control and related heterostructures construction via CVD method are reviewed and discussed, including wafer-scale synthesis, phase transition, doping, alloy and stacking engineering. Meanwhile, recent progress on the application of multi-functional devices is highlighted based on 2D TMDs. Finally, challenges and prospects are proposed for the practical device applications of 2D TMDs. 相似文献
116.
A new nonlinear wave equation of a finite deformation elastic circular rod simultaneously introducing transverse inertia and shearing strain was derived by means of Hamilton principle. The nonlinear equation includes two nonlinear terms caused by finite deformation and double geometric dispersion effects caused by transverse inertia and transverse shearing strain. Nonlinear wave equation and corresponding truncated nonlinear wave equation were solved by the hyperbolic secant function finite expansion method. The solitary wave solutions of these nonlinear equations were obtained. The necessary condition of these solutions existence was given also. 相似文献
117.
Cobalt-free perovskite oxide La0.5Sr0.5Fe0.8Cu0.2O3 − δ (LSFC) was applied as both anode and cathode for symmetrical solid oxide fuel cells (SSOFCs). The LSFC shows a reversible transition between a cubic perovskite phase in air and a mixture of SrFeLaO4, a K2NiF4-type layered perovskite oxide, metallic Cu and LaFeO3 in reducing atmosphere at elevated temperature. The average thermal expansion coefficient of LSFC in air is 17.7 × 10− 6 K− 1 at 25 °C to 900 °C. By adopting LSFC as initial electrodes to fabricate electrolyte supported SSOFCs, the cells generate maximum power output of 1054, 795 and 577 mW cm− 2 with humidified H2 fuel (~ 3% H2O) and 895, 721 and 482 mW cm− 2 with humidified syngas fuel (H2:CO = 1:1) at 900, 850 and 800 °C, respectively. Moreover, the cell with humidified H2 fuel demonstrates a reasonable stability at 800 °C under 0.7 V for 100 h. 相似文献
118.
Mixing ionic liquids (ILs) has been revealed as a useful way to finely tune the properties of IL-based solvents. The scarce available studies on IL mixtures have shown a quasi-ideal behavior of their physical properties. In this work, we have performed a thermophysical characterization of two binary IL mixtures, namely {4-methyl-N-butylpyridinium bis(trifluoromethylsulfonyl)imide ([4bmpy][Tf2N]) + 1-ethyl-3-methylimidazolium ethylsulfate ([emim][EtSO4])} and {[4bmpy][Tf2N] + 1-ethyl-3-methylimidazolium 1,1,2,2-tetrafluoroethanesulfonate [emim][TFES]}. Both binary IL mixtures have been recently proposed as promising solvents in the (liquid + liquid) extraction of aromatic hydrocarbons from mixtures with alkanes. Densities, viscosities, refractive indices, thermal stability, and specific heats of the {[4bmpy][Tf2N] + [emim][EtSO4]} and {[4bmpy][Tf2N] + [emim][TFES]} IL mixtures have been measured as a function of both temperature and composition. Dynamic viscosities, refractive indices, and thermal stability of the {[4bmpy][Tf2N] + [emim][EtSO4]} mixture have exhibited strong deviations from the ideality, in contrast with the quasi-ideal properties of the {[4bmpy][Tf2N] + [emim][TFES]} mixture and the behavior of the imidazolium and pyridinium-based IL mixtures studied hitherto. The reliability of predictive methods of the thermophysical properties of the mixtures has also been evaluated. 相似文献
119.
Graphene oxide (GO) was functionalized using three different diamines, namely ethylenediamine (EDA), 4,4′-diaminodiphenyl sulfone (DDS) and p-phenylenediamine (PPD) to reinforce an epoxy adhesive, with the aim of improving the bonding strength of carbon fiber/epoxy composite. The chemical structure of the functionalized GO (FGO) nanosheets was characterized by elemental analysis, FT-IR and XRD. Hand lay-up, as a simple method, was applied for 3-ply composite fabrication. In the sample preparation, the fiber-to-resin ratio of 40:60 (w:w) and fiber orientations of 0°, 90°, and 0° were used. The GO and FGO nanoparticles were first dispersed in the epoxy resin, and then the GO and FGO reinforced epoxy (GO- or FGO-epoxy) were directly introduced into the carbon fiber layers to improve the mechanical properties. The GO and FGO contents varied in the range of 0.1–0.5 wt%. Results showed that the mechanical properties, in terms of tensile and flexural properties, were mainly dependent on the type of GO functionalization followed by the percentage of modified GO. As a result, both the tensile and flexural strengths are effectively enhanced by the FGOs addition. The tensile and flexural moduli are also increased by the FGO filling in the epoxy resin due to the excellent elastic modulus of FGO. The optimal FGO content for effectively improving the overall composite mechanical performance was found to be 0.3 wt%. Scanning electron microscopy (SEM) revealed that the failure mechanism of carbon fibers pulled out from the epoxy matrix contributed to the enhancement of the mechanical performance of the epoxy. These results show that diamine FGOs can strengthen the interfacial bonding between the carbon fibers and the epoxy adhesive. 相似文献
120.