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71.
A novel phase-change composites based on silicone rubber (MVQ) containing n-octadecane/poly (styrene-methyl methacrylate) microcapsules were successfully obtained by mixing energy-storage microcapsules into MVQ matrix using three preparation methods. The effect of microcapsules content on thermal property of the composites was investigated by thermogravimetric analysis. The mechanical properties of the composites prepared by three methods were also investigated. The morphology and thermal properties of the composites were characterized by scanning electron microscopy (SEM), differential scanning calorimetry, and thermal response. Thermal and mechanical properties of the composites were excellent when the microcapsules were added into room temperature vulcanized silicone rubber with 2 phr (per hundred rubber) content and cured at room temperature. The composites were proved to have good energy-storage performance with 67.6 J g?1 enthalpy value. 相似文献
72.
Yu Zhang Weimeng Chi Baiqing Zhang Zhuoxun Yin Xinzhi Ma Yang Zhou Wei Chen Lingling Xu Jinlong Li 《欧洲无机化学杂志》2023,26(34):e202300492
The conventional electrolytic water-splitting process for hydrogen production is plagued by high energy consumption, low efficiency, and the requirement of expensive catalysts. Therefore, finding effective, affordable, and stable catalysts to drive this reaction is urgently needed. We report a nanosheet catalyst composed of carbon nanotubes encapsulated with MoC/Mo2C, the Ni@MoC-700 nanosheet showcases low overpotentials of 275 mV for the oxygen evolution reaction and 173 mV for the hydrogen evolution reaction at a current density of 10 mA ⋅ cm−2. Particularly noteworthy is its outstanding performance in a two-electrode system, where a cell potential of merely 1.64 V is sufficient to achieve the desired current density of 10 mA ⋅ cm−2. Furthermore, the catalyst demonstrates exceptional durability, maintaining its activity over a continuous operation of 40 hours with only minimal attenuation in overpotential. These outstanding activity levels and long-term stability unequivocally highlight the promising potential of the Ni@MoC-700 catalyst for large-scale water-splitting applications. 相似文献
73.
Bairui Tao Keyang Zhao Fengjuan Miao Zaishun Jin Jianbo Yu Paul K. Chu 《Ionics》2016,22(10):1891-1898
A Pd-Ni nanoparticle modified silicon-based anode is fabricated and the possibility of using it for the direct alkaline fuel cell of carbohydrates has been investigated by electrochemical method. Upright and porous ordered silicon nanowires (SiNWs) arrays are prepared by wet etching. The Pd-Ni nanoparticles are covered to the SiNWs uniformly by chemical deposited successively. Using six kinds of common carbohydrate, including glucose, fructose, maltose, lactose, sucrose, and starch, as testing subjects, the performance of electrocatalytic oxidation is studied. Experiment results show that the electrochemically active surface area of Pd-Ni/SiNWs electrode electrochemically active surface area is 53.482 cm2, and higher electrocatalytic activity and stability is displayed for the direct oxidation of glucose, fructose, maltose, and lactose. Firstly, the Pd-Ni/SiNWs electrode has better electrochemical performance for carbohydrates and is promising for applications in direct alkaline fuel. Secondly, more kinds of carbohydrates might potentially use as energy source for direct alkaline fuel. 相似文献
74.
以包覆Si O2的Fe3O4为载体,吡嘧磺隆(PS)为模板分子,甲基丙烯酸(MAA)为功能单体,乙二醇二甲基丙烯酸酯(EDMA)为交联剂,通过表面印迹法制备了磁性PS分子印迹聚合物(MIP),采用红外光谱、扫描电镜对其结构进行表征,采用吸附实验对其性能进行研究,并以MIP为固相萃取填料,结合高效液相色谱进行检测。结果表明,MIP对PS的饱和吸附量为68.94mg/g,印迹因子为2.49。将本方法应用于大米中PS残留分析,回收率在87.73%~99.57%范围内,相对标准偏差低于5.51%。所制备的MIP对样品中PS的富集、分离效果良好。 相似文献
75.
以顺丁烯二酸酐-β-环糊精(MAH-β-CD)、甲基丙烯酸缩水甘油酯(GMA)和二甲基丙烯酸乙二醇酯(EDMA)为功能单体,一步键合制备了环糊精衍生物毛细管整体柱,并对其制备条件进行优化。通过红外光谱和扫描电镜对整体柱固定相的结构和形貌进行表征。以硫脲为中性标记物测得柱效为99856 plates/m。通过精氨酸对柱子进行评价,所制备的新型手性整体柱具有较强的手性拆分能力,且重现性好、操作简单。用毛细管电色谱-质谱联用技术(CEC-MS)拆分了沙丁胺醇对映体,分离度为1.67。 相似文献
76.
Yanxin Lv Song Jin Yu Wang Zhiqiang Lun Chunhui Xia 《Journal of the Iranian Chemical Society》2016,13(10):1767-1776
Due to the critical role of glucose level in the diagnosis and treatment of diabetes, as well as the increasing number of diabetics, there is an overwhelming demand for developing glucose sensors. It is well acknowledged that these sensors, especially those based on glucose oxidase, have played an important role in blood glucose detection. Inspired by the attractive properties, nanomaterials, especially nanostructured carbon and metal/metal oxides, have been extensively explored to develop enzymatic glucose sensors with high sensitivity, fast response time, and satisfied stability. In this review, a brief history of glucose biosensors is firstly presented. Furthermore, we discuss the currently available fabrication possesses in the field of enzymatic glucose biosensors based on nanomaterials, focusing on the carbon-based, metal-based, and metal oxides-based nanocomposites. What is more, we discuss the challenges and attempt to give an outlook on the possible further developments. 相似文献
77.
用质子条件式PBE、物料平衡式MBE、副反应系数和条件稳定常数等知识,推导出一元强碱滴定二元弱酸溶液的林邦滴定曲线方程,并用其推导出第一、第二化学计量点pH_(sp1)和pH_(sp2)的计算公式。 相似文献
78.
79.
《Polyhedron》1999,18(8-9):1323-1328
The coordination mode of the title ligand, MPyPzCA (synthesised for the first time and characterised by elemental analyses, mass, IR and PMR spectral parameters), is reported by solid state isolation and physicochemical identification of copper(II) complexes, Cu(MPyPzCA)2X2.H2O (X=Cl/Br/NO3/ClO4). Magnetic and electronic spectral features classify the reported complexes as six coordinate distorted octahedral ones. IR spectra (4000–200 cm−1) of MPyPzCA and its complexes indicate different denticity of the two ligand moities namely neutral bidentate function through pyrazolyl 2N and pyridyl 1′N of one ligand (A) and the neutral tridentate behaviour through pyrazolyl 2N, pyridyl 1′N and the amidic oxygen of the second ligand system (B). The sixth apical coordination site is occupied by a water molecule in the perchlorate complex (as evident by X-ray data) or by the counter ion, X (X=Cl/Br/NO3). The electrochemical studies demonstrate easy oxidative nature of Cu(II) in the reported species. X-ray crystallographic studies of the perchlorate complex, [Cu(MPyPzCA)2(H2O)](ClO4)2, (Pna21, orthorhombic), has substantiated the conjecture that the geometry is distorted octahedral. The Cu-N (pyrazolyl) and Cu-N (pyridyl) bond lengths are 2.001(3) and 1.969(3) Å and 2.020(4) and 2.206(4) Å in the ligand systems, A and B. respectively; Cu-O (amidic oxygen) for ligand system B and Cu-O (water) bond lengths are 2.783(3) and 2.010(3) Å, respectively. The crystal structure is highly stabilised through extensive hydrogen bonding. 相似文献
80.
Domaines fictifs, éléments finis H(div) et condition de Neumann: le problème de la condition inf-sup
《Comptes Rendus de l'Academie des Sciences Series IIA Earth and Planetary Science》1999,328(12):1225-1230
Approximation of the Neumann problem for a second order elliptic operator by a fictitious domain method with a Lagrange multiplier on the boundary is considered. The problem is written in its vectorial dual formulation and H(div) mixed finite elements for the vector unknown and H1/2 conforming elements for the multiplier are used. The uniform inf-sup condition is demonstrated under a compatibility condition between surface and volume meshes. 相似文献