Li Ma

Roles of Al-doped ZnO (AZO) modification layer on improving electrochemical performance of LiNi1/3Co1/3Mn1/3O2 thin film cathode

Al-doped ZnO (AZO) was sputtered on the surface of LiNi1/3Co1/3Mn1/3O2 (NCM) thin film electrode via radio frequency magnetron sputtering, which was demonstrated to be a useful approach to enhance electrochemical performance of thin film electrode. The structure and morphology of the prepared electrodes were characterized by X-ray diffraction, scanning electron microscopy, energy dispersive spectrometer, and transmission electron microscopy techniques. The results clearly demonstrated that NCM thin film showed a strong (104) preferred orientation and AZO was uniformly covered on the surface of NCM electrode. After 200xa0cycles at 50xa0μAxa0μm−1xa0cm−2, the NCM/AZO-60s electrode delivered highest discharge capacity (78.1xa0μAhxa0μm−1xa0cm−2) compared with that of the NCM/AZO-120s electrode (62.4xa0μAhxa0μm−1xa0cm−2) and the bare NCM electrode (22.3xa0μAhxa0μm−1xa0cm−2). In addition, the rate capability of the NCM/AZO-60s electrode was superior to the NCM/AZO-120s and bare NCM electrodes. The improved electrochemical performance can be ascribed to the appropriate thickness of the AZO coating layer, which not only acted as HF scavenger to keep a stable electrode/electrolyte interface but also reduced the charge transfer resistance during cycling.

Micro/nano hierarchical structured titanium treated by NH4OH/H2O2 for enhancing cell response

In this paper, two kinds of titanium surfaces with novel micro/nano hierarchical structures, namely Etched (E) surface and Sandblast and etched (SE) surface, were successfully fabricated by NH4OH and H2O2 mixture. And their cellular responses of MG63 were investigated compared with Sandblast and acid-etching (SLA) surface. Scanning electron microscope (SEM), Surface profiler, X-ray photoelectron spectroscopy (XPS), and Contact angle instrument were employed to assess the surface morphologies, roughness, chemistry and wettability respectively. Hierarchical structures with micro holes of 10–30 μm in diameter and nano pits of tens of nanometers in diameter formed on both E and SE surfaces. The size of micro holes is very close to osteoblast cell, which makes them wonderful beds for osteoblast. Moreover, these two kinds of surfaces possess similar roughness and superior hydrophilicity to SLA. Reactive oxygen species were detected on E and SE surface, and thus considerable antimicrobial performance and well fixation can be speculated on them. The cell experiments also demonstrated a boost in cell attachment, and that proliferation and osteogenic differentiation were achieved on them, especially on SE surface. The results indicate that the treatment of pure titanium with H2O2/NH4OH is an effective technique to improve the initial stability of implants and enhance the osseointegration, which may be a promising surface treatment to titanium implant.

Synthesis of (Ni, Co)Fe2O4-Spinel Coating Using High Temperature Oxidation Treatment of Ni-Co-Fe2O3 Composite Electrodeposited Coating

Ni-Co-Fe2O3 composite coatings are successfully developed via conventional electrodeposition technology. The effects of electrodeposition parameters on the content of Fe2O3 particles in the composite coating and, of surfactants on the texture coefficient of the composite coating were investigated. It is found that electrodeposition parameters play an important role in controlling the composition, the grain size and the preferred orientation of the composite coatings. Composite coatings with high content of Fe2O3 particles and high (100) texture were obtained. A (Ni, Co)Fe2O4-spinel coating was obtained by the oxidation treatment of as-plated Ni-Co-Fe2O3 composite coatings with high content of Fe2O3 particles performed in air at 1000°C for 6h.

A Study on the Oxidation Behavior of Nickel Coatings with Different Grain Sizes and Preferred Orientations

Ni coatings with different grain sizes and preferred orientations were produced by the control of current density during a direct current electrodepositing process. The effects of grain size reduction and preferred orientation on the oxidation behavior in air at 600°C and 960°C of Ni coatings were investigated respectively. An important and interesting result is that after oxidation at 600°C, the Ni coating obtained at lower current density has a better oxidation resistance, whereas after oxidation at 960°C, the Ni coating obtained at higher current density has a more compact scale and a better oxidation resistance. For the Ni coatings oxidation at 600°C, the oxidation behavior was mainly influenced by grain size, whereas in the case of the Ni coatings oxidation at 960°C, the oxidation behavior was only slightly influenced by grain size. The changes in oxidation behavior of Ni coatings at 960°C can be attributed to the different preferred orientation and the corresponding oxidation mechanism.

Ultrasound enhanced electrochemical oxidation of Alizarin Red S on boron doped diamond(BDD) anode:Effect of degradation process parameters

Textile wastewater is characterized by high toxicity, complex structure, and resistance to biodegradation. Therefore, advanced oxidation technologies have received extensive attention. However, it is usually difficult to achieve a desired degradation effect using a single technology. The combination of various advanced oxidation technologies is an important way to achieve efficient degradation of organic wastewater. The present investigation was focused on ultrasound enhanced electrochemical oxidation (US-EO) of typical anthracene Alizarin Red S dye on a boron doped diamond anode. Our work indicates that ultrasonic oxidation technology which is mainly based on cavitation, can produce strongly oxidizing active substances such as OH, HO2, O, and H2O2, that accelerate the destruction of the dye molecular structure and achieve dye decolorization and mineralization. The effects on cavitation and decomposition of ARS by the parameters that affect degradation, including solution temperature, initial pH, and electrolytes, were examined. Results show that low temperature was more conducive to ultrasonic cavitation in the US-EO process; the degradation efficiency rate of EO was higher than that of US-EO when the solution temperature was above 45u202f°C. Ultrasonic cavitation was significantly more efficient in acid than in alkaline conditions. Almost 100% color removal and 86.07% COD removal was achieved for 100u202fmgu202fL-1 ARS concentration with a 0.05u202fM Na2SO4 electrolyte, temperature of 30u202f°C and pH of 4.97 after 3u202fh. GC-MS analysis showed that the intermediate products of ARS in the US-EO process were phthalic anhydride, PEAs and bisphenol A, which is eventually mineralized to CO2 and H2O.

The Effects of Combined Micron-Scale Surface and Different Nanoscale Features on Cell Response

Sandblasting and acid-etching (SLA) and anodization are the two most commonly used methods for surface modification of biomedical titanium. However, there are unavoidable problems such as residual sand particles and lack of hydrophilicity on the surface of titanium sheets treated with SLA technology. In addition, titanium implants showed only the micro/submicroscopic structure. In order to avoid the residue of sand particles in the surface of titanium, the two surface treatments etching treatment (E) and etched-anodizing (EA) on titanium were used, and their surface topography, surface chemistry, and surface roughness were compared with those of the SLA control group. Their wettability and the biocompatibility were also compared and evaluated. The results show that both E and EA samples have the micro/nano hierarchical structure and better wettability compared with the SLA samples. Their performances, especially the E surfaces, were enhanced in terms of cell adhesion, spreading, proliferation, and differentiation abilities.

Study on Reinforcement Methods Based on Different Disintegration Mechanism of Red Sandstone Landslides in Changji Highway

Based on the engineering properties of red sandstone, especially hydraulic mechanical properties, red sandstone slopes are taken as examples. Polarized microscope, powder X-ray diffraction and several general experimental analyses are conducted to get some basic physical indices and microstructure parameters. By summarizing and comparing to other scholars research results, this paper analyzes the disintegration mechanism and failure mechanism of the red sandstone Slope. Several examples of slopes reinforcement projects of Changji highway in Hunan province are taken for the analysis of red sandstone rock properties deeply. Meanwhile, a comprehensive analysis is carried out between three red sandstone slopes instability mechanisms. Finally, some more practical reinforcement methods will be discussed in this article which would do favor to provide scientific basis for disaster prevention and mitigation.