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171.
《Electrochemistry communications》2007,9(2):221-227
The novel bismuth modifying technique for disposable thick film carbon containing sensors (TFCC) by means of a surface synthesis of the modifier (bismuth phosphate) have been developed. The optimal composition and the method of cathodic reduction (“activation”) of the modifying BiPO4 layer has been proposed. These conditions provided the structure of a modifying layer with the bismuth nano particles of size less than 0.1 μm. On the important analytical parameters (sensitivity, accuracy, tolerance to surfactant fouling effect, particularly for Zn), sensor developed (TFCC/BiPO4) surpasses TFCC with electrolytic bismuth films. The detection limit of 8 nM for zinc, 4 nM for cadmium and 2 nM for lead was achieved after a 2 min accumulation. Therefore, the developed non-toxic and low cost disposable sensor excludes the necessity of mechanical pretreatment of a working surface and can be used in field, laboratory and automatic systems for environmental monitoring (at the trace level inclusive). 相似文献
172.
《Electrochemistry communications》2007,9(3):425-430
TiO2 nanotubes prepared by using a hydrothermal process were firstly coated with silver nanoparticles as the anode materials for lithium–ion batteries by the traditional silver mirror reaction. The physical properties of the as-synthesized samples were investigated by X-ray diffraction and transmission electron microscopic. The as-prepared samples were used as negative materials for lithium–ion battery, whose charge–discharge properties, cyclic voltammetry, electrochemical impedance spectroscopy and cycle performance were examined in detail. The results showed that the Ag additive decreased the polarization of anode, and marvelously improved the high-rate discharge capacity and cycling stability of TiO2 nanotubes. 相似文献
173.
174.
Andrzej Czopnik Nataly Shitsevalova Alexander Krivchikov Vasyl Pluzhnikov Yuriy Paderno 《Journal of solid state chemistry》2004,177(2):507-514
We have measured heat capacity and thermal expansion of rare earth dodecaborides REB12 (RE=Y, Tb-Tm, Lu). YB12 and LuB12 are diamagnetics whereas the other dodecaborides are ordered antiferromagnetically. The amplitude of the heat capacity discontinuity at the Néel temperature and the shape of the heat capacity variation in the critical region for all these antiferromagnetics are characteristics for amplitude-modulated magnetic structures. In the ordered state TbB12 reveals two first-order phase transitions, most likely due to magnetic structure changes. The heat capacity of ErB12 just below the Néel point shows an anomaly of unclear origin. From the Schottky contribution to the heat capacity we have determined crystal field parameters. They are completely different than that is estimated from Point Charge Model. 相似文献
175.
Takao Masuda 《Catalysis Surveys from Asia》2003,7(2-3):133-144
The diffusion mechanisms within zeolite catalysts, such as resistance to diffusion at pore mouths, configurational diffusion, adsorption-controlled diffusion, influence of co-existing molecules and pore blocking, were overviewed. Two kinds of diffusivities, the intracrystalline diffusivity and the effective diffusivity, were discussed separately to clarify the diffusion mechanism. 相似文献
176.
177.
《Polyhedron》2005,24(16-17):2405-2408
A 3He refrigerator mountable to a commercial SQUID magnetometer has been developed, which enables us to measure static magnetizations of a sample at temperatures below 2 K conveniently. The design and usage of the system are outlined. We have applied this to study static magnetic properties of an organic ferromagnet, β-p-NPNN, and have confirmed that the saturation magnetization is 1 μB per molecule. No hysteretic behavior has been detected, when the field was applied along the easy axis. This indicates that β-p-NPNN is a very soft magnet, as expected for an isotropic Heisenberg magnet based on organic radicals. 相似文献
178.
《中国化学快报》2020,31(4):922-930
MXenes have emerged as versatile 2D materials that are already gaining paramount attention in the areas of energy,catalyst,electromagnetic shielding,and sensors.The unique surface chemistry,graphene-like mo rphology,high hydrophilicity,metal-like conductivity with redox capability identifies MXenes,as an ideal material for surface-related applications.This short review summarizes the most recent reports that discuss the potential application of MXenes and their hybrids as a transducer material for advanced sensors.Based on the nature of transducing signals,the discussion is categorized into three sections,which include electrochemical(bio) sensors,gas sensors,and finally,electro-chemiluminescence fluorescent sensors.The review provides a concise summary of all the analytical merits obtained subsequent to the use of MXenes,followed by endeavors that have been made to accentuate the future perspective of MXenes in sensor devices. 相似文献
179.
Szekeres E Acosta E Sabatini DA Harwell JH 《Journal of colloid and interface science》2005,287(1):273-287
Solubilization of dodecanol-limonene binary oil mixtures has been studied in saturated Winsor type I and III sodium dihexyl sulfosuccinate microemulsions. The systems showed different oil solubilization behavior below and above dodecanol volume fraction 0.2. Below 0.2 dodecanol volume fraction regular Winsor type microemulsions formed. The oil solubilization was characterized in this concentration range by the optimum salinity and the maximum characteristic length. Dodecanol showed Langmuirian-type surface excess adsorption at the vicinity of the surfactant layer. Variation of the optimum salinity and middle phase characteristic length with increasing dodecanol concentration could be linked to changes in the dodecanol surface excess. These relationships were used to develop new mathematical models for the optimum salinity and characteristic length as a function of oil phase composition. Both models yield excellent agreement with the data. Above dodecanol volume fraction 0.2 regular Winsor type III microemulsions are not formed. Therefore our new models are not applicable in this concentration range. 相似文献
180.
Surface composition and property of film prepared with aqueous dispersion of polyurethaneurea-acrylate including fluorinated block copolymer 总被引:1,自引:0,他引:1
The aqueous dispersion of polyurethaneurea-acrylate (PUA) including small amount of fluorinated block copolymers containing carboxyl groups (PATF), which can be dissolved in water, was used to make films and the surface properties of these films were examined. The experimental data show that the modified PUA film exhibits a hydrophobic surface property, although the original surface of PUA film is hydrophilic. The surface composition of the modified PUA film was measured by ATR and XPS. The results indicate that there is a concentration gradient of the fluorine groups along the lines of thickness of the modified film and towards the outmost surface layer, resulting from the migration of fluorinated blocks to the air side surface of the modified PUA film during the film formation process. However, the PUA film can not be modified effectively by adding the sodium salt of PATF, since the urethane groups in the system are easy to occupy on the surface of the film. 相似文献