查看更多>>摘要：A steady-state magnetic field is introduced to prepare Fe-Ni coating based on laser-assisted electrodeposition (LECD) to control the change of element content and improve the surface quality. The internal structure, surface quality, and properties are tested to discuss under different magnetic field intensities. The results indicate that the comprehensive performance of Fe-Ni coating with a transverse magnetic field is better. The magnetohydrodynamic (MHD) and magnetization effect make the grain refinement and improve the surface quality of Fe-Ni coating. The surface morphology shows that the laser makes the surface denser, while the magnetic field causes the ions to magnetize so that the clusters form on the surface. The addition of the magnetic field does not change the grain structure, but the Fe content is increased because of the MHD effect on the diffusion degree. Besides, when the magnetic field intensity is 15 mT, the residual internal stress reaches 587 MPa in the form of compressive stress. Meanwhile, the test of micro-hardness, tensile strength, wear, and corrosion resistance indicates that the comprehensive performance of Fe-Ni coating by the magnetic field and laserassisted electrodeposition (MLECD) is better than that of electrodeposition (ECD) and LECD.
查看更多>>摘要：The theory is developed for the chronoamperometry of first order homogeneous catalytic chemical reaction coupled with electron transfer (EC') on a rough electrode. We obtained a solution for the diffusion problem on an arbitrary and random topography of the electrode to generalize Danckwerts' equation. Derived equation of random electrode roughness is used for developing theory of (statistically isotropic) self-affine fractal on limited length scales. The characteristics fractal morphological parameters, viz. D-H, l and l(tau), are varied for detailed analysis of current transient. The current transient shows anomalously enhanced response for a rough electrode. Our theoretical results explain both transient and steady-state behavior of the current response under the influence of roughness. The anomalous enhancement of steady-state current is only observed when RMS roughness is greater than bulk reaction-diffusion length (L-k). Finally, the theory is compared and validated with experimental data of ferrocyanide and ascorbic acid coupled system on rough Pt electrodes.
Sanz, Caroline G.Mihaila, Andreea C.Evanghelidis, AlexandruDiculescu, Victor C....
9页
查看更多>>摘要：The present study brings developments in the area of tissue engineering of heart valves, with the design and application of a new 2D model for human heart valve. This model contains valvular interstitial cells (VIC) encapsulated in gold covered electrospun polycaprolactone (PCL/Au) fibers, the latter serving also as an electrochemical sensor that enables the monitoring of oxygen levels of cellular media. The biocompatibility of PCL and PCL/Au with VIC was evaluated after the encapsulation of VIC in both scaffolds using the lactate dehydrogenase assay. Fluorescence microscopy of the encapsulated cells was used for the investigation of cell morphology, by employing phalloidin labelled F-actin (red) and DAPI nuclear staining (blue). The electrochemical techniques allowed to investigate the effect of cell encapsulation within the PCL/Au 2D constructs and to quantify the dissolved oxygen levels in cell culture media at both PCL/Au and PCL/Au with encapsulated cells (PCL/ Au/cells). Experiments were performed in a hypoxistation, which allowed a fine control on the cellular media oxygenation. Electrochemical impedance spectroscopy (EIS) was used to evaluate the electrochemical behavior of the 2D constructs, PCL/Au and PCL/Au/cells, in cellular media at different O-2 concentration. Results were analyzed and both impedance values at a fixed frequency and values of the equivalent circuit elements were used to construct calibration curves for dissolved O-2 determination. The second electrochemical technique used to monitor the levels of O-2 at PCL/Au and PCL/Au/cells in the cellular media was square wave voltammetry with sensitivities of 1.5 and 2.5 mu A cm(-2) mu M-1, for PCL/Au and PCL/Au/cells, respectively.
Ding, KangLee, Lawrence Yoon SukWong, Kwok-YinLee, Jeongyeon...
8页
查看更多>>摘要：Hierarchical or mesoporous-structured molybdenum disulfides (MoS2) are one of the promising anode materials for lithium-ion batteries (LIBs) owing to their abundant active sites, fast ion transport, and easy permeation of electrolyte. However, the synthesis of such architectures with precise structural control is challenging, often requiring preliminary fabrication of templates or special equipment. Herein, we report hierarchical and mesoporous MoS2 frameworks (HM-MoS2) synthesized via a facile phase-segregation route, where ZnS nanoparticles are in situ formed as the hard template. The mesopores and interconnected channels created by removing ZnS nanoparticles enable the uniform carbon coating on HM-MoS2. When employed as an anode in LIB, the HM-MoS2 of an optimal carbon coating exhibits a high rate capability of 396.8 mA.h g(-1) at 10 A g(-1) and a prolonged cyclability with only 2.8 % of capacity decay.
查看更多>>摘要：As one of the common food allergens, milk proteins can cause severe allergic reactions. Among them, 8-lactoglobulin can cause about 60% of IgE-mediated milk allergies. Thus, in this research, a new type of label-free photoelectrochemical immunosensor on the basis of CdS quantum dots (QDs) sensitized CdWO4-TiO2 heterojunction was developed for the sensitive detection of 8-lactoglobulin. CdWO4 was synthesized by one-step hydrothermal method, and CdWO4-TiO2 was prepared by one-step hydrothermal coating method. The existence of CdS QDs greatly promoted the separation of photoelectrons and holes, and improved the response of CdWO4-TiO2 to visible light. Under the best experimental conditions, the constructed sensor exhibits excellent performance. In the range of 0.005 ng center dot mL-1 to 10 ng center dot mL-1, the photocurrent intensity and the logarithm of 8-lactoglobulin concentration show an excellent linear relationship, and the limit of detection is 0.88 pg center dot mL-1. At the same time, the constructed sensor has good stability and reproducibility. It provides a new idea for the sensitive and fast detection of 8-lactoglobulin and the analysis of other biological samples.
NSTL
Elsevier