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991.
MnO超微粒子的制备及其对PEMFC电催化性能的研究 总被引:4,自引:0,他引:4
用微乳液法合成了 Mn O超微粒子 ,探讨了影响萃取率及粒度的因素 ,得到了最佳反应条件 ,并用透射电子显微镜 (TEM)、X射线衍射仪 (XRD)及红外光谱 (FTIR)进行了表征。得到了粒径为 5 nm左右的 Mn O超微粒子 ,并在质子交换膜燃料电池 (PEMFC)的铂电极中加入 5 nm的Mn O超微粒子作为催化剂 ,改变了电池的放电机理 ,提高了输出电压。为 PEMFC的商品化进行了有价值的探索。 相似文献
992.
Imidazolium ionic liquid incorporation on sulfonated poly(styrene‐isobutylene‐styrene) proton exchange membranes 下载免费PDF全文
Ionic liquids (ILs) with different anions and cations were incorporated in sulfonated poly(styrene‐isobutylene‐styrene) (SIBS) to modify its chemical, morphological, and transport properties for direct methanol fuel cell (DMFC) applications. Different loadings of IL and different solvents were studied to have a better understanding of the incorporation process and the ability of the solvent to affect the interaction of the IL with the sulfonated polymer. Morphological characterization with SAXS and AFM suggested changes caused by the incorporation of the IL and by the solvent used. FT‐IR spectra showed small variations in energy related to interactions of the IL with the sulfonic groups which caused thermogravimetric stabilization of the ionic domains. Other results suggest that water has a very significant effect on the morphology, interaction with the IL, and transport properties of the membranes. Optimal concentration of IL (~10 mol %) provides enough water to produce efficient proton conductivity (0.15 S/cm) and minimal methanol permeability (0.8 × 10?6 cm2/s). © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134 , 44900. 相似文献
993.
Pore orientation of the gadolinia‐doped ceria cathode interlayer for a tubular SOFC using dip‐coating 下载免费PDF全文
Bo Liang Silong Zhang Shengguo Lu Sheng Sui Jinlei Shang 《International Journal of Applied Ceramic Technology》2017,14(2):185-190
An active region of cathode interlayer in a tubular solid oxide fuel cell (SOFC) is structurally analyzed using a dual‐beam focused ion beam/scanning electron microscope (FIB/SEM). The GDC (10 mol% gadolinia‐doped ceria) cathode interlayer (about 1 μm in thickness) is dip‐coated, and then sintered on YSZ (8 mol% yttria‐stabilized zirconia) electrolyte. At 1150°C sintering temperature, the pores oriented more along the axial direction than the radial direction. The anisotropy of pore shape is accounted for the withdrawal force during the dip‐coating of the GDC interlayer. 相似文献
994.
Abstract The kinetics of the forward and backward extraction of the title process have been investigated using a Lewis cell operated at 3 Hz and flux or (F) – method of data treatment. The dependences of (F) in the forward extraction on [Fe3+], [H2A2](o), pH, and [HSO4 ?] are 1, 0.5, 1, and ?1, respectively. The value of the forward extraction rate constant (k f ) has been estimated to be 10?7.37 kmol3/2 m?7/2 s?1. The analysis of the experimentally found flux equation gives the following simple equation: F f =100.13 [FeHSO4 2+] [A?], on considering the monomeric model of BTMPPA and the stability constants of Fe(III)‐HSO4 ? complexes. This indicates the following elementary reaction occurring in the aqueous film of the interface as rate determining: [FeHSO4]2++A?→[FeHSO4.A]+. The very high activation energy of 91 kJ mol?1 supports this chemical reaction step as rate-determining. The negative value of the entropy change of activation (?94 J mol?1 K?1) indicates that the slow chemical reaction step occurs via the SN2 mechanism. The backward extraction rate can be expressed by the equation: F b =10?5.13 [[FeHSO4A2]](o) [H+] [H2A2](o) ?0.5. An analysis of this equation leads to the following chemical reaction step as rate-determining: [FeHSO4A2](int)→[FeHSO4A]+A(i) ?. However, the activation energy of 24 kJ mol?1 suggests that the backward extraction process is intermediate controlled with greater contribution of the diffusion of one or the other species as a slow process. The equilibrium constant obtained from the rate study matches well with that obtained from the equilibrium study. 相似文献
995.
Paolo Sarti Maria Chiara Magnifico Fabio Altieri Daniela Mastronicola Marzia Arese 《International journal of molecular sciences》2013,14(6):11259-11276
Extending our previous observations, we have shown on HaCat cells that melatonin, at ~10−9 M concentration, transiently raises not only the expression of the neuronal nitric oxide synthase (nNOS) mRNA, but also the nNOS protein synthesis and the nitric oxide oxidation products, nitrite and nitrate. Interestingly, from the cell bioenergetic point of view, the activated NO-related chemistry induces a mild decrease of the oxidative phosphorylation (OXPHOS) efficiency, paralleled by a depression of the mitochondrial membrane potential. The OXPHOS depression is apparently balanced by glycolysis. The mitochondrial effects described have been detected only at nanomolar concentration of melatonin and within a time window of a few hours’ incubation; both findings compatible with the melatonin circadian cycle. 相似文献
996.
Silicon nanowire (SiNW) arrays show an excellent light-trapping characteristic and high mobility for carriers. Surface plasmon resonance of silver nanoparticles (AgNPs) can be used to increase light scattering and absorption in solar cells. We fabricated a new kind of SiNW/organic hybrid solar cell by introducing AgNPs. Reflection spectra confirm the improved light scattering of AgNP-decorated SiNW arrays. A double-junction tandem structure was designed to manufacture our hybrid cells. Both short-circuit current and external quantum efficiency measurements show an enhancement in optical absorption of organic layer, especially at lower wavelengths. 相似文献
997.
Jin Yao Hui-E Bi Yi Sheng Li-Bo Cheng Ri-Le Wendu Cheng-Hu Wang Guo-Fan Cao Qin Jiang 《International journal of molecular sciences》2013,14(5):10355-10368
Ultraviolet (UV) radiation and reactive oxygen species (ROS) impair the physiological functions of retinal pigment epithelium (RPE) cells by inducing cell apoptosis, which is the main cause of age-related macular degeneration (AMD). The mechanism by which UV/ROS induces RPE cell death is not fully addressed. Here, we observed the activation of a ceramide-endoplasmic reticulum (ER) stress-AMP activated protein kinase (AMPK) signaling axis in UV and hydrogen peroxide (H2O2)-treated RPE cells. UV and H2O2 induced an early ceramide production, profound ER stress and AMPK activation. Pharmacological inhibitors against ER stress (salubrinal), ceramide production (fumonisin B1) and AMPK activation (compound C) suppressed UV- and H2O2-induced RPE cell apoptosis. Conversely, cell permeable short-chain C6 ceramide and AMPK activator AICAR (5-amino-1-β-D-ribofuranosyl-imidazole-4-carboxamide) mimicked UV and H2O2’s effects and promoted RPE cell apoptosis. Together, these results suggest that UV/H2O2 activates the ceramide-ER stress-AMPK signaling axis to promote RPE cell apoptosis. 相似文献
998.
Lin Gao 《Electrochimica acta》2004,49(8):1281-1287
Yields were determined for the CO2 produced upon the electrochemical oxidation of 1.0 M methanol in 0.1 M HClO4 at the following four fuel cell catalyst systems: Pt black, Pt at 10 wt.% metal loading on Vulcan XC-72R carbon (C/Pt, 10%), PtRu black at 50 at.% Pt, 50 at.% Ru (PtRu (50:50) black), and PtRu at 30 wt.% Pt, 15 wt.% Ru loading on Vulcan XC-72R carbon (C/PtRu, 30 wt.% Pt, 15 wt.% Ru). Samples were electrolyzed in a small volume (50 μl) arrangement for a period of 180 s keeping the reactant depletion in the cell below 1%. The dissolved CO2 produced was determined ex situ by infrared spectroscopy in a micro-volume transmission flow cell. For the PtRu materials, the efficiencies for CO2 formation were near 100% at reaction potentials in the range between 0.4 V (versus the reversible hydrogen electrode (RHE), VRHE ) and 0.9 VRHE. At the Pt catalysts, the yields of CO2 approached 80% between 0.8 and 1.1 VRHE and declined rapidly below 0.8 VRHE. 相似文献
999.
固定化脱氮硫杆菌净化硫化氢气体的研究 总被引:16,自引:0,他引:16
以海藻酸钙包埋脱氮硫杆菌制成的固定化微生物颗粒填充生物固定床,用以净化低浓度H2S废气。实验研究了温度、pH值、进气浓度及流速对反应体系中的H2S脱除率的影响,测定了生物固定床中代谢物的种类及其含量。结果表明当进气口的质量浓度低于6×10-5mg/L、25~40℃、pH值在6.0~7.5范围时,生物固定床对废气中H2S的脱除率可达90%以上,在反应过程中pH值保持不变;进气口的流速对不同浓度的H2S的影响较大,当进气口H2S质量浓度为3×10-5mg/L且流速在35L/h时,脱除率高达95%以上。元素硫作为主要产物防止了生物固定床的酸化,并保证脱硫装置的稳定性。 相似文献
1000.