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排序方式: 共有620条查询结果,搜索用时 406 毫秒
611.
V.A.G. Rivera S. Sergeenkov E. Marega F.M. Araújo-Moreira 《Physica C: Superconductivity and its Applications》2010,470(21):1946-1948
A pronounced resonance-like structure has been observed in the current dependence of AC susceptibility for two-dimensional array of unshunted Nb–Alx–Nb Josephson junctions. Using a single-plaquette approximation, we were able to successfully fit our data assuming that resonance structure is related to the geometric (inductive) properties of the array. 相似文献
612.
Mariana Stoica Monica Caldararu N. I. Ionescu 《Reaction Kinetics and Catalysis Letters》1999,66(2):387-392
Hydrogen desorption, hydrogen spillover and reduction processes have been evidenced using a new experimental strategy based
on AC electric conductivity measurements during TPD and TPR experiments on a 0.5% Pt/Al2O3 catalyst. 相似文献
613.
醋酸锌与草酸的分步固相反应 总被引:2,自引:0,他引:2
The solid state reaction of zinc acetate with oxalic acid was found to be two-step reactions. It was a double reaction which the second reaction takes place before the first ceased. The method of isothermal TG wasn′t fit to this type of reaction because of the limitation of the volatilization rate of acetic acid at the low heat temperature, but the method of isothermal electric conductivity exhibited its superiority. 相似文献
614.
一种制备铂支撑自组装双层类脂膜新方法 总被引:4,自引:0,他引:4
利 用高功 率超声对 铂电极表 面进行 清洗, 并在 超声 清洗 后的 铂电 极 表面 上形 成 铂支撑自组 装双层 类脂膜( Pt_ B L M) .该方法 简便快 速,可以制 备较大 面积的双 层类脂 膜,并克服 切割法消耗铂 丝较多 的缺点.研 究表明 用该方 法制 备 的 Pt_ B L M 不 仅与 切割 法 制备 的 Pt_ B L M 具 有 吻合的电容 值和循 环伏安特 性,而且 还有良好 的稳定 性. 相似文献
615.
The dependence of the differential capacitance of polypyrrole doped with several typical dopants on potential is presented, which shows that the differential capacitance varies with the potential, the doped polypyrroles with electroactive ions give the largest capacitance near their formal potentials, which is attributed to the mutual media for electron transfer between polypyrrole and electroactive dopants. The existence of two conducting phases was observed in the complex capacitance plots. The electroactive anions act as an intra-conducting-phase medium for electron transfer, the electroactive cations act as an inter-conducting phase medium for electron transfer. The mutual media between polypyrrole and redox dopants lead to the increase of the discharging time. 相似文献
616.
本文逐步运用初始条件,建立了双组分三角波交流示波极谱理论。该理论可较好地还原到前文报道的单组分状态时的各类方程,与实验结果一致。讨论了影响去极剂切口性质的主要因素,如去极剂浓度,前还原组分浓度以及三角波电流直流分量和电流扫描速率。 相似文献
617.
PEG600和CH2Cl2通过Williamson缩聚反应,生成主链柔顺的PEG共聚物.1H NMR测试表明其以[CH2O(CH2>CH2O)13]为重复结构单元.与聚合物质量含量8%的气相SiO2及适量的LiN(CF3SO2)2掺杂,制备一系列新型复合聚合物电解质.通过AC阻抗研究离子电导率,提出适合本体系的等效电路.该体系具有良好的成膜性能与热稳定性能,电导率比传统的PEO/盐体系高2~3个数量级.离子电导率随着温度的升高而增加,低温电导率增加较快,高温电导率增加较慢,呈非Arrhenius变化.在EO/Li=13~34:1(摩尔比)范围内,离子电导率随着盐浓度的变化出现两个峰值,低盐浓度的峰值较高.在303 K, EO/Li=28:1时,最大离子电导率接近10-4 S/cm. 相似文献
618.
Rudolf Pietschnig Tatjana Langkau Rolf Neuser Frank Hipler Julia Hambrock Sven Schfer 《Macromolecular rapid communications》2003,24(4):303-306
This paper describes the preparation and characterization of a novel ion‐conducting polymeric material ( 2 ). The backbone consists of alternating alkenylidene and sulfanylidene units with adjacent hydroxy groups. Fitting of the experimental impedance data of 2 in a Bode plot reveals a conductivity of 6.6 × 10−2 S · cm−1 and a capacitance of 2.2 × 10−5 F at room temperature. The deuterated derivative of 2 shows significantly lower conductivity, suggesting that the conductivity of 2 can be attributed to proton migration.
619.
Tamara A. Bazhenova Vyacheslav A. Kopotkov Denis V. Korchagin Yuriy V. Manakin Leokadiya V. Zorina Sergey V. Simonov Ilya A. Yakushev Vladimir S. Mironov Alexander N. Vasiliev Olga V. Maximova Eduard B. Yagubskii 《Molecules (Basel, Switzerland)》2021,26(22)
A series of six seven-coordinate pentagonal-bipyramidal (PBP) erbium complexes, with acyclic pentadentate [N3O2] Schiff-base ligands, 2,6-diacetylpyridine bis-(4-methoxybenzoylhydrazone) [H2DAPMBH], or 2,6-diacethylpyridine bis(salicylhydrazone) [H4DAPS], and various apical ligands in different charge states were synthesized: [Er(DAPMBH)(C2H5OH)Cl] (1); [Er(DAPMBH)(H2O)Cl]·2C2H5OH (2); [Er(DAPMBH)(CH3OH)Cl] (3); [Er(DAPMBH)(CH3OH)(N3)] (4); [(Et3H)N]+[Er(H2DAPS)Cl2]− (5); and [(Et3H)N]+[Y0.95Er0.05(H2DAPS)Cl2]− (6). The physicochemical properties, crystal structures, and the DC and AC magnetic properties of 1–6 were studied. The AC magnetic measurements revealed that most of Compounds 1–6 are field-induced single-molecule magnets, with estimated magnetization energy barriers, Ueff ≈ 16–28 K. The experimental study of the magnetic properties was complemented by theoretical analysis based on ab initio and crystal field calculations. An experimental and theoretical study of the magnetism of 1–6 shows the subtle impact of the type and charge state of the axial ligands on the SMM properties of these complexes. 相似文献
620.
A. S. Kumar L. Iype R. Rajesh G. Varughese G. Joseph G. Louis 《Crystal Research and Technology》2011,46(10):1027-1034
Single crystals of potassium sulfamate are grown by the method of slow evaporation at constant temperature. AC electrical conductivity of potassium sulfamate is measured in the temperature range 300–430 K and in the frequency region between 100 Hz and 3 MHz along the a, b and c‐axes. Complex impedance spectroscopy is used to investigate the frequency response of the electrical properties of the potassium sulfamate single crystal. Temperature variation of AC conductivity and dielectric measurements show a slope change around 345 K for both heating and cooling run and this anomaly is attributed as phase transition, which is well supported by the DSC measurements. Value of loss tangent in the temperature region 330–400 K is found to be very low. Activation energies for the conduction process are calculated along the a, b and c‐axes. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献