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101.
以D-木糖为炭源,月桂酸钠为模板剂,硼酸为掺杂剂,通过水热炭化方法制得硼掺杂分级多孔炭球(BPCS)。通过扫描电子显微镜(SEM)、透射电子显微镜(TEM)、N2吸附-脱附测试、X射线光电子能谱(XPS)、顺磁共振波谱(EPR)、傅里叶红外光谱(FT-IR)、拉曼光谱(Raman)、X射线粉末衍射(XRD)、热重(TG)分析对样品进行表征。结果表明:月桂酸钠作为介孔造孔剂的同时,通过与D-木糖间的氢键作用使有机-有机自组装过程自发进行并形成窄尺寸分布(2~5 μm)规整炭球;硼酸在水热中催化炭源脱水降解,并以BC3、BCO2和BC2O的形式掺杂在炭球上,掺硼后炭球与水表面接触角降低,润湿性提高。经CO2活化、月桂酸钠高温分解以及胶质炭球的堆积分别产生微孔(0.5~1.2 nm)、介孔(3.14~35.00 nm)和大孔(60~146 nm)并形成分级结构。当硼酸加入量为0.927 5 g时多孔炭球(BPCS-1)的电化学性能最佳,在6 mol·L-1 KOH三电极体系中电流密度为0.5 A·g-1时,比电容达287.12 F·g-1;两电极体系中电流密度为0.5 A·g-1时比电容达151.34 F·g-1,能量密度达5.3 Wh·kg-1;电流密度为5 A·g-1时进行1 000次充放电循环,电容保持率仍达96.43%。 相似文献
102.
The Effect of the Modification of Carbon Spheres with ZnCl2 on the Adsorption Properties towards CO2
Iwona Peech Piotr Staciwa Daniel Sibera Ewelina Kusiak-Nejman Antoni W. Morawski Joanna Kapica-Kozar Urszula Narkiewicz 《Molecules (Basel, Switzerland)》2022,27(4)
Zinc chloride and potassium oxalate are often applied as activating agents for carbon materials. In this work, we present the preparation of ZnO/carbon spheres composites using resorcinol-formaldehyde resin as a carbon source in a solvothermal reactor heated with microwaves. Zinc chloride as a zinc oxide source and potassium oxalate as an activating agent were applied. The effect of their addition and preparation conditions on the adsorption properties towards carbon dioxide at 0 °C and 25 °C were investigated. Additionally, for all tested sorbents, the CO2 sorption tests at 40 °C, carried out utilizing a thermobalance, confirmed the trend of sorption capacity measured at 0 and 25 °C. Furthermore, the sample activated using potassium oxalate and modified using zinc chloride (a carbon-to-zinc ratio equal to 10:1) displayed not only a high CO2 adsorption capacity (2.69 mmol CO2/g at 40 °C) but also exhibited a stable performance during the consecutive multicycle adsorption–desorption process. 相似文献
103.
Hong-yu Li Zhi-qiang Chen Hai-qiao Wang Bo Meng Xiao-yu Li 《高分子科学》2007,(2):217-220
Ordered macroporous titania photonic crystals (PCs) and photonic balls were fabricated by functional modified polymer colloidal crystals. The TiO2 PCs and balls formed through this method exhibit no cracks and lacunae in large areas on their surface and their inner structures. 相似文献
104.
刘秀贵 《数学物理学报(A辑)》2007,27(2)
决定球面稳定同伦群是同伦论中的核心问题之一,是非常重要的.该文证明:球面稳定同伦元素α1β1βs是一个阶为p的非平凡元素,其中p≥5是任意奇素数,1≤s
相似文献
105.
设$p\geq 7$素数,$A$为模$p$的Steenrod代数. 我们利用Adams谱序列证明了球面稳定同伦群$\pi_{\ast}S$中,存在由$b_1g_0\tilde{\gamma}_{s}\in Ext_A^{s+4,(s+1)p^2q+spq+sq+s-3}(Z_p,Z_p)$所表示的新的非平凡元素族,其中$q=2(p-1)$, $3\leq s
相似文献
106.
107.
Charge transport and contact resistance in coplanar devices based on colloidal polyaniline dispersion
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Appan Merari Masillamani Nikola Peřinka Milena Hajná Jaroslav Stejskal Denis Tondelier Yvan Bonnassieux Jean‐Charles Vanel Bernard Geffroy Denis Mencaraglia 《Journal of Polymer Science.Polymer Physics》2016,54(17):1710-1716
The charge transport properties of thin films prepared from colloidal dispersion of polyaniline stabilized by poly(N‐vinylpyrrolidone) (PANI/PVP) have been investigated. The electrical characterization of coplanar device comprising of gold electrodes and PANI/PVP film deposited by spin coating served to gain insights into the contact and bulk resistance. The films prepared from PANI/PVP colloidal dispersion show high stability over a large temperature range. Temperature dependent measurements in the range from 90 to 350 K reveal that the charge transport can be described by a three‐dimensional variable‐range hopping mechanism as the dominant mode in the films. The stability of the films cast from dispersion within a large temperature range opens the possibility of the application as a polymer semiconductor layer in sensors and charge‐transport interlayer in organic solar cells. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2016 , 54, 1710–1716 相似文献
108.
CaII Binding Regulates and Dominates the Reactivity of a Transition‐Metal‐Ion‐Dependent Diesterase from Mycobacterium tuberculosis
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Dr. Marcelo M. Pedroso Prof. James A. Larrabee Dr. Fernanda Ely Shuhui E. Gwee Dr. Nataša Mitić Prof. David L. Ollis Prof. Lawrence R. Gahan Prof. Gerhard Schenk 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(3):999-1009
The diesterase Rv0805 from Mycobacterium tuberculosis is a dinuclear metallohydrolase that plays an important role in signal transduction by controlling the intracellular levels of cyclic nucleotides. As Rv0805 is essential for mycobacterial growth it is a promising new target for the development of chemotherapeutics to treat tuberculosis. The in vivo metal‐ion composition of Rv0805 is subject to debate. Here, we demonstrate that the active site accommodates two divalent transition metal ions with binding affinities ranging from approximately 50 nm for MnII to about 600 nm for ZnII. In contrast, the enzyme GpdQ from Enterobacter aerogenes, despite having a coordination sphere identical to that of Rv0805, binds only one metal ion in the absence of substrate, thus demonstrating the significance of the outer sphere to modulate metal‐ion binding and enzymatic reactivity. CaII also binds tightly to Rv0805 (Kd≈40 nm ), but kinetic, calorimetric, and spectroscopic data indicate that two CaII ions bind at a site different from the dinuclear transition‐metal‐ion binding site. CaII acts as an activator of the enzymatic activity but is able to promote the hydrolysis of substrates even in the absence of transition‐metal ions, thus providing an effective strategy for the regulation of the enzymatic activity. 相似文献
109.
Gautam Gundiah M Eswaramoorthy S Neeraj Srinivasan Natarajan C N R Rao 《Journal of Chemical Sciences》2001,113(3):227-234
Mesoporous aluminosilicate spheres of 0.3–0.4 Μm diameter, with different Si/Al ratios, have been prepared by surfactant templating.
Surface area of these materials is in the 510–970 m2 g-1 range and pore diameter in the 15–20 ? range. 相似文献
110.
Wilderich Tuschmann 《Proceedings of the American Mathematical Society》2002,130(1):303-306
A recent injectivity radius estimate and previous sphere theorems yield the following smooth diameter sphere theorem for manifolds of positive Ricci curvature: For any given and there exists a positive constant 0$">such that any -dimensional complete Riemannian manifold with Ricci curvature , sectional curvature and diameter is Lipschitz close and diffeomorphic to the standard unit -sphere. A similar statement holds when the diameter is replaced by the first eigenvalue of the Laplacian.