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81.
In this paper, Si/carbon nanotubes@melamine-formaldehyde resin (MFR)-based carbon (Si/CNTs@C) composites have been fabricated by surface modification, electrostatic self-assembly, cross-linking of MFR under hydrothermal treatment and further carbonization. The microstructure of the Si/CNTs@C composites was characterized, and the effects of CNTs content in Si/CNTs@C composites on their electrochemical performances were also investigated in detail. The results indicate Si/CNTs@C composites as anode materials of Li-ion batteries exhibit better high-rate and cycling performances compared to Si and Si@MFR-based carbon composites. Notably, Si/CNTs@C composites with 10.4 wt% CNTs show specific capacities of 1900, 1879, 1,688, 1,394, 1,189 mAh·g−1 at 0.2, 0.5, 1, 2, and 3 A·g−1, respectively. Even at 4 and 5 A·g−1, their capacities still reach 970 and 752 mAh·g−1, respectively. Moreover, they deliver a reversible capacity of 1,184 mAh·g−1 at 0.5 A·g−1 after 100 cycles. Therefore, the reasonable structure is of great significance for enhancing the electrochemical performances of Si-based composites. 相似文献
82.
Hybrid anion exchange membranes (AEMs) were prepared via chemically functionalizing and crosslinking poly(styrene-b-[ethylene-co-butylene]-b-styrene) (SEBS) copolymers and low molecular weight homo-polystyrene (hPS). Via sequential chloromethylation, crosslinking, quaternization, and alkalization, a series of hPS/SEBS AEMs were obtained with varying content of hPS. Systematic structural, morphological, mechanical, absorption, and transport measurements reveal that these properties depend on the total PS content in the membranes. Particularly, increasing total PS content causes (a) PS domains in the AEMs transition the cylindrical morphology to lamella-like morphology with comparable correlation length; (b) Young's modulus, water uptake, swelling ratio, ionic exchange capacity and ionic conductivity of the AEMs, and Tg of PS phase increase. In addition, the alkaline stability of the hPS/SEBS AEMs is also improved by addition of hPS. These findings suggest that the proposed method can develop high performance SEBS AEMs that are suitable for fuel cell applications. 相似文献
83.
Irina A. Stenina Polina A. Yurova Tatyana S. Titova Marina A. Polovkova Oleg V. Korchagin Vera A. Bogdanovskaya Andrey B. Yaroslavtsev 《应用聚合物科学杂志》2021,138(27):50644
Nafion-117/PEDOT composite membranes were synthesized by in situ chemical polymerization of 3,4-ethylenedioxythiophene (EDOT) using ammonium persulfate as an oxidant. The polymerization of EDOT in Nafion membranes for various EDOT/oxidant treatment sequences was studied for the first time. PEDOT introduction leads to a slight decrease in both the ion-exchange capacity and water uptake of the composite membranes, as well as to an increase in cationic transport. Membranes initially treated with an oxidant exhibit better conductivity and lower hydrogen permeability. The effect of both modification of Nafion-117 membranes by PEDOT and hot-pressing of hydrogen-oxygen membrane-electrode assemblies (MEAs) on the performance of proton-exchange membrane fuel cells was studied. The maximum power density of the fabricated MEAs increases 1.5-fold: from 510 (for a pristine Nafion-117 membrane) to 810 mW cm−2 (for a membrane modified by PEDOT). The current density at a voltage of 0.4 V reaches 1248 and 2246 mA cm−2, respectively. 相似文献
84.
85.
The oxidation of Ni to NiO in solid oxide fuel cell (SOFC) anode will result in large bulk volume change, which may change the interfaces of the two phases in the anode cermet and thus may cause significant performance degradation. The reduction and oxidation (redox) of the Ni/YSZ cermet were studied at 800 ℃. Anodic polarization measurements were performed before and after redox cycles. The anode current density at an overpotential of 100 mV kept decreasing during the whole redox treatment. It decreased from 19.11 to 7.95 mA·cm-2 after two redox cycles. Anode supported unit cell was assembled for cell's discharge measurements. Cell performance declined after each redox cycle. The maximum power density decreased from 126.28 to 40.32 mW·cm-2 . The microstructural changes after redox cycling were recorded using scanning electron microscopy (SEM). The results reveal that after re-oxidation, the Ni gets coarse and has a higher porosity; the nickel network structure turns to be desultory. 相似文献
86.
Characterization of YSZ solid oxide fuel cells electrolyte deposited by atmospheric plasma spraying and low pressure plasma spraying 总被引:1,自引:0,他引:1
C. Zhang H. L. Liao W. Y. Li G. Zhang C. Coddet C. Zhang C. J. Li C. X. Li X. J. Ning 《Journal of Thermal Spray Technology》2006,15(4):598-603
Yttria doped zirconia has been widely used as electrolyte materials for solid oxide fuel cells (SOFC). Plasma spraying is
a cost-effective process to deposit YSZ electrolyte. In this study, the 8 mol% Y2O3 stabilized ZrO2 (YSZ) layer was deposited by low pressure plasma spraying (LPPS) and atmospheric plasma spraying (APS) with fused-crushed
and agglomerated powders to examine the effect of spray method and particle size on the electrical conductivity and gas permeability
of YSZ coating. The microstructure of YSZ coating was characterized by scanning electron microscopy and x-ray diffraction
analysis. The results showed that the gas permeability was significantly influenced by powder structure. The gas permeability
of YSZ coating deposited by fused-crushed powder is one order lower in magnitude than that by agglomerated powder. Moreover,
the gas permeability of YSZ deposited by LPPS is lower than that of APS YSZ. The electrical conductivity of the deposits through
thickness direction was measured by potentiostat/galvanostat based on three-electrode assembly approach. The electrical conductivity
of YSZ coating deposited by low pressure plasma spraying with fused-crushed powder of small particle size was 0.043 S cm−1 at 100 °C, which is about 20% higher than that of atmospheric plasma spraying YSZ with the same powder.
This article was originally published inBuilding on 100 Years of Success, Proceedings of the 2006 International Thermal Spray Conference (Seattle, WA), May 15–18, 2006, B.R. Marple, M.M. Hyland, Y.-Ch. Lau, R.S. Lima, and J. Voyer, Ed., ASM International, Materials
Park, OH, 2006. 相似文献
87.
Nanocrystalline titania films codoped with aluminum and boron were prepared by cathodic vacuum arc deposition. In the process, titanium alloy target was used under an O2/Ar atmosphere, and sensitization of films were carried out by natural dye-sensitized complex in anhydrous ethanol. The structure, surface morphology and UV-vis spectra of titania films codoped were measured by X-ray diffraction analysis, scanning electron microscopy and ultraviolet-visible spectrometer. Theas-deposited films are found to be amorphous. The films annealed were examinedto be of anatase structure with orientation along the (101) planes, the averagecrystal size is in the range between 41 and 45 nm. SEM results show that thereare some pores in the codoped titania films, the optical properties of the dye-sensitized films were also measured which reveals that the spectral responses of films shift to the visible region. Under simulated sunlight illumination, the overall energy conversion efficiency of dye-sensitized nanocrystalline solar cell is 0.9%. 相似文献
88.
In this work, nanopowders of perovskite cathode materials (La0.8Sr0.2MnO3−δ, La0.8Sr0.2FeO3−δ, and La0.8Sr0.2CoO3−δ), for use in solid oxide fuel cells (SOFC), were successfully synthesized, using induction plasma techniques. Their compositions,
structures, morphology, particle size distributions, and BET specific surface areas were determined for comparison with their
counterparts prepared by the Pechini method and by the glycine-nitrate combustion (GNC) technique. The particle sizes of the
plasma-synthesized powders are mostly around 63 nm. These plasma-synthesized powders are generally globular, their BET specific
surface areas being about 26 m2g−1, approximately twice those of powders prepared by the GNC and Pechini methods. These plasma-synthesized powders are readily
reproducible and are not agglomerated. Their individual particle sizes and distributions are very independent of their composition. 相似文献
89.
R. Etchart-Salas V. Rat J. F. Coudert P. Fauchais N. Caron K. Wittman S. Alexandre 《Journal of Thermal Spray Technology》2007,16(5-6):857-865
Direct current Suspension Plasma Spraying (SPS) allows depositing finely structured coatings. This article presents an analysis
of the influence of plasma instabilities on the yttria-stabilized suspension drops fragmentation. A particular attention is
paid to the treatment of suspension jet or drops according to the importance of voltage fluctuations (linked to those of the
arc root) and depending on the different spray parameters such as the plasma forming gas mixture composition and mass flow
rate and the suspension momentum. By observing the suspension drops injection with a fast shutter camera and a laser flash
sheet triggered by a defined transient voltage level of the plasma torch, the influence of plasma fluctuations on jet or drops
fragmentation is studied through the deviation and dispersion trajectories of droplets within the plasma jet.
This article is an invited paper selected from presentations at the 2007 International Thermal Spray Conference and has been
expanded from the original presentation. It is simultaneously published in Global Coating Solutions, Proceedings of the 2007 International Thermal Spray Conference, Beijing, China, May 14-16, 2007, Basil R. Marple, Margaret M. Hyland, Yuk-Chiu Lau, Chang-Jiu Li, Rogerio S. Lima, and Ghislain
Montavon, Ed., ASM International, Materials Park, OH, 2007. 相似文献
90.
Onno B. Bleijerveld Ya-Nan Zhang Serap Beldar Imo E. Hoefer Siu K. Sze Gerard Pasterkamp Dominique P. V. de Kleijn 《Proteomics. Clinical applications》2013,7(7-8):490-503
Cardiovascular disease (CVD) is the leading cause of death and loss of productive life years in the world. The underlying syndrome of CVD, atherosclerosis, is a complex disease process, which involves lipid metabolism, inflammation, innate and adaptive immunity, and many other pathophysiological aspects. Furthermore, CVD is influenced by genetic as well as environmental factors. Early detection of CVD and identification of patients at risk are crucial to reduce the burden of disease and to allow personalized treatment. As established risk factors fail to accurately predict which part of the population is likely to suffer from the disease, novel biomarkers are urgently needed. Proteomics can play a significant role in identifying these biomarkers. In this review, we describe the progress made in proteome profiling of the atherosclerotic plaque and several novel sources of potential biomarkers, including circulating cells and plasma extracellular vesicles. The importance of longitudinal biobanking in biomarker discovery is highlighted and exemplified by several plaque proteins identified in the biobank study Athero-Express. Finally, we discuss the PTMs of proteins that are involved in atherosclerosis, which may become one of the foci in the ongoing quest for biomarkers through proteomics of plaque and other matrices relevant to the progression of atherosclerosis. 相似文献