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991.
Kai Zhao Yunman Wei Penglu Zhao Dejian Kong Tianbo Gao Xinxiang Pan Junsheng Wang 《Electrophoresis》2023,44(15-16):1210-1219
Wear debris analysis provides an early warning of mechanical transmission system aging and wear fault diagnosis, which has been widely used in machine health monitoring. The ability to detect and distinguish the ferromagnetic and nonmagnetic debris in oil is becoming an effective way to assess the health status of machinery. In this work, an Fe-poly(dimethylsiloxane) (PDMS)-based magnetophoretic method for the continuous separation of ferromagnetic iron particles by diameter and the isolation of ferromagnetic particles and nonmagnetic particles with similar diameter by type is developed. The particles experience magnetophoretic effects when passing through the vicinity of the Fe-PDMS where the strongest gradient of the magnetic fields exists. By choosing a relatively short distance between the magnet and the sidewall of the horizontal main channel and the length of Fe-PDMS with controlled particles flow rate, the diameter-dependent separation of ferromagnetic iron particles, that is, smaller than 7 µm, in the range of 8–12 µm, and larger than 14 µm, and the isolation of ferromagnetic iron particles and nonmagnetic aluminum particles based on opposite magnetophoretic behaviors by types are demonstrated, providing a potential method for the detection of wear debris particles with a high sensitivity and resolution and the diagnostic of mechanical system. 相似文献
992.
Siqi Zhang Fuhua Huang Dr. Xugeng Guo Ye Xiong Yafei Huang Prof. Dr. Hans Ågren Prof. Dr. Li Wang Prof. Dr. Jinglai Zhang 《Angewandte Chemie (International ed. in English)》2023,62(23):e202302753
We report a new strategy to fabricate a multifunctional composite photoanode containing TiO2 hollow spheres (TiO2-HSs), Au nanoparticles (AuNPs) and novel NaYF4 : Yb,Er@NaLuF4 : Eu@SiO2 upconversion nanoparticles (UCNPs). The AuNPs are grown on the photoanode film including TiO2-HSs and UCNPs by a simple in situ plasmonic treatment. As a result, an impressive power conversion efficiency of 14.13 % is obtained, which is a record for N719 dye-based dye-sensitized solar cells, demonstrating great potential for the solar cells toward commercialization. This obvious enhancement is ascribed to a collaborative mechanism of the TiO2-HSs exhibiting excellent light-scattering ability, of the UCNPs converting near-infrared photons into visible photons and of the AuNPs presenting outstanding surface plasmon resonance effect. Notably, a steady-state experiment further reveals that the champion cell exhibits 95.33 % retainment in efficiency even after 180 h of measurements, showing good device stability. 相似文献
993.
Monodispersed Fe3O4/polypyrrole (PPy) hollow particles were synthesized via controllable in-situ deposition and polymerization techniques using poly(styrene-co-acrylic) (PSA) latex as template. Field-dependent magnetization plot illustrates that the capsules are superparamagnetic at 300 K. FTIR spectrum confirms that the myoglobin (Mb) molecule adsorbed on the surface of Fe3O4/PPy hollow particle essentially retains its native structure. Furthermore, direct electrochemistry of Mb can be realized on Fe3O4/PPy capsules modified pyrolytic graphite disk electrode, which indicates that the magnetic conductive polymer capsules can promote the electron transfer of protein. 相似文献
994.
为了获得良好性能的柞蚕丝素复合膜,本文采用复合法制备了不同配比柞蚕丝素/纳米TiO2复合膜,并与纯的丝素膜作了比较,用SEM、DSC、TG和IR进行了表征.SEM测试表明在分散剂聚乙烯醇作用下,适量的纳米TiO2能均匀分散丝素溶液中.DSC测试表明复合膜b、c和d的Tm均高于纯的柞蚕丝素膜a的Tm,然而随着纳米TiO2加入量的继续增加,对应复合膜的Tm有所降低.TG结果表明,随着纳米TiO2加入量的增加,复合膜的热稳定性得到提高.IR测试表明丝素复合膜的结晶结构从Silk I向SilkII转化. 相似文献
995.
Soon Hyung Kang Jae-Yup Kim Hyun Sik Kim Haeng-Deog Koh Jae-Suk Lee Yung-Eun Sung 《Journal of photochemistry and photobiology. A, Chemistry》2008,200(2-3):294-300
A TiO2 film was modified by adding light scattering particles and applied to an anode electrode in solid-state dye-sensitized solar cells (DSSCs). The TiO2 films with 10 wt% (vs. TiO2 weight) light scattering particles showed enhanced performance (28%), compared with nanocrystalline TiO2 films, which were used as the controls. In particular, the photocurrent density (Jsc) reached approximately 12.6 mA/cm2 under a one-sun condition. This was attributed to the light scattering effect and decrease in internal resistance through the macroporous structure with a minor loss of electron transport. However, in the case of a larger concentration of light scattering particles (>10 wt%), there was a decrease in the efficiency of DSSCs, which resulted from the decreased surface area and degraded electron transport and charge recombination properties, as confirmed by the measurement of stepped light-induced photocurrent and photovoltage transients. Furthermore, the diffusion properties and kinetics of the composite polymer electrolyte with the nanoporous and macroporous TiO2 films were compared and evaluated from the electrochemical impedance spectra. 相似文献
996.
Metallic Ag nanoparticles-incorporating titania films were prepared using the sol-gel method. X-ray diffraction (XRD) patterns,
UV/Vis optical spectra and transmission electron microscopy (TEM) images were recorded to characterize the Ag/titania composite
films. Electrometer was used to estimate the resistance of Ag/titania composite film to understand the effect of the incorporation
of metallic Ag nanoparticles on the electrical properties of titania film. The results showed that metallic Ag nanoparticles
distributed randomly in titania film and most metallic Ag particles size was in the range of 5–15 nm. The agglomeration of
a small quantity of metallic Ag particles occurred and when the amount of Ag species was increased the agglomeration was enhanced.
The resistance of Ag/titania composite films decreased greatly compared with pure titania film. 相似文献
997.
P. L. Teh M. Jaafar H. M. Akil K. N. Seetharamu A. N. R. Wagiman K. S. Beh 《先进技术聚合物》2008,19(4):308-315
Epoxy composites containing particulate fillers‐fused silica, glass powder, and mineral silica were investigated to be used as substrate materials in electronic packaging application. The content of fillers were varied between 0 and 40 vol%. The effects of the fillers on the thermal properties—thermal stability, thermal expansion and dynamic mechanical properties of the epoxy composites were studied, and it was found that fused silica, glass powder, and mineral silica increase the thermal stability and dynamic thermal mechanical properties and reduce the coefficient of thermal expansion (CTE). The lowest CTE value was observed at a fused silica content of 40 vol% for the epoxy composites, which was traced to the effect of its nature of low intrinsic CTE value of the fillers. The mechanical properties of the epoxy composites were determined in both flexural and single‐edge notch (SEN‐T) fracture toughness properties. Highest flexural strength, stiffness, and toughness values were observed at fillers content of 40 vol% for all the filled epoxy composites. Scanning electron microscopy (SEM) micrograph showed poor filler–matrix interaction in glass powder filled epoxy composites at 40 vol%. Copyright © 2007 John Wiley & Sons, Ltd. 相似文献
998.
A novel thin-film composite (TFC) membrane for nanofiltration (NF) was developed by the interfacial polymerization of triethanolamine (TEOA) and trimesoyl chloride (TMC) on the polysulfone (PSf) supporting membrane. The active surface of the membrane was characterized by using FT-IR, XPS and SEM. The performance of TFC membrane was optimized by studying the preparation parameters, such as the reaction time of polymerization, pH of aqueous phase and the concentration of reactive monomers. It is found that the membrane performance is related to the changes of the monomer content in the aqueous phase rather than in the organic phase. Furthermore, the nanofiltration properties of the TFC membrane were tested by examining the separating performance of various salts at 0.6 MPa operating pressure. The rejection to different salt solutions decreased as per the order of Na2SO4 (82.2%), MgSO4 (76.5%), NaCl (42.2%) and MgCl2 (23%). Also, streaming potential tests indicated that isoelectric point of the TFC membrane is between pH 4 and 5. Moreover, the investigation of the flux for NaCl solution at different pH showed that the polyester NF composite membrane is also particularly suitable for treating acidic feeds: the flux increased from 8.4 to 11.5 L/m2 h when pH of the feed decreased from 9 to 3. Additionally, the TFC membrane exhibits good long-term stability. 相似文献
999.
A special type of hybrid nano-particles was incorporated into the Nafion® matrix to form a composite membrane. These nano-particles possessed a core–shell structure consisting of silica core (<10 nm) and a densely grafted oligomeric ionmer layer, which was synthesized via atom transfer radical polymerization (ATRP) on the particles’ surface. Besides considerable improvement in the proton conductivity of the membrane, the presence of these hybrid nano-particles in the Nafion® matrix also repressed its methanol permeability by almost four times. The composite membrane also demonstrated superior performance when tested in a single cell membrane-electrolyte assembly (MEA) under direct methanol fuel cell (DMFC) operating condition. It was found that the composite membrane enabled a power density output that was 1.5 times greater than that of pristine Nafion®. 相似文献
1000.
We prepared Nafion/PTFE (NF) and zirconium phosphate (ZrP) hybridized Nafion/PTFE composite membranes (NF–ZrP). NF–ZrP composite membranes were prepared via two processes. One is impregnating sub-μm porous PTFE membrane directly in a Nafion/ZrOCl2 solution (NF–Zr–d). The other is impregnating sub-μm porous PTFE membrane in a Nafion solution to prepare NF composite membrane, and then the NF membrane was impregnated in a ZrOCl2 aqueous solution via in situ precipitation method (NF–Zr–I). The ZrOCl2 inserted in NF composite membranes was then reacted with phosphoric acid to form ZrP and thus NF–ZrP–d and NF–ZrP–I composite membranes were obtained. The direct methanol fuel cell (DMFC) performances of membrane electrode assemblies prepared from Nafion-117, NF, NF–ZrP–d, and NF–ZrP–I composite membranes were investigated. The effects of introducing sub-μm porous PTFE film and ZrP particles into Nafion membranes on the DMFC performance were investigated. The influence of ZrP hybridizing process into NF membranes (the process of preparing NF–ZrP–I is inserting ZrOCl2 into NF membranes after Nafion is annealed and the process of preparing NF–ZrP–d is mixing ZrOCl2 into a Nafion solution before Nafion is annealed) on the morphology of NF–ZrP composite membranes and thus on the DMFC performance was also discussed. 相似文献