Advanced Materials Research Vols. 554-556

Abstract: The high-capacity cathode materials with the same average composition of Li[Ni0.7Co0.15Mn0.15]O2 but with three different surface composition were prepared. The structural and electrochemical properties of the materials were studied using X-ray diffraction (XRD), scanning electron microscope (SEM), charge–discharge tests and electrochemical impedance spectra (EIS). The results showed that all of the prepared materials have a well-ordering layered single-phase NaFeO2 structure. Among the three samples, Li[(Ni_0.8Co_0.1Mn_0.1)_0.66(Ni_0.5Co_0.25Mn_0.25)_0.33]O₂ exhibit the best electrochemical performance, due to its lower Ni-content on the material surface ensuring a better reduction of the electrolyte decomposition than that of Li[Ni_0.7Co_0.15Mn_0.15]O₂, and its structure with a concentration-gradient shell enabling more smooth Li+ diffusion than Li[(Ni_0.79Co_0.21O₂)_0.7(Ni_0.5Mn_0.5)_0.3]O₂. It presents an initial capacity of 179.6 mAh•g^-1 and 99.0% of capacity retention after 25 cycles.

Abstract: In this paper, the electrochemical behavior of promethazine hydrochloride (PMT) and its interaction with bovine serum albumin (BSA) were studied by means of cyclic voltammetry. In pH 6.5 Tris-HCl buffer solution, PMT exhibits a pair of reversible peaks and an irreversible oxidation peak at a bare gold electrode. The electrode reactions are the process controlled by adsorption. The results of cyclic voltammetry suggest that a BSA-PMT complex is formed, and this complex is not electroactive. The absorption spectra confirm the binding PMT to BSA. The binding number m and the binding constant β of BSA binding to PMT are 2.10 and 7.43×10⁵ L/mol, respectively.

Abstract: The photodissociation of B/KNO₃ (40:60, wt %) mixture, following 532nm laser excitation was investigated by echelle-type spectrometer and time of flight mass spectrometer (TOFMS). The ablation products contained a lot of ions and molecular fraction. Emission spectra and mass spectra of the intermediate products were obtained. According to the possible distribution of the products, multistep reaction mechanism of B/KNO₃ is proposed.

Abstract: Residual stresses in green compacts have a significant influence on the quality of the compact and post-compaction processes like part handling. In this study, the latest European and American standard for residual stress measurement by X-ray diffraction have been used to obtain more exact residual stresses in surface of green compacts as experimental evidence for simulation. The influence of kinds of powders, compacting pressure and friction on residual stresses in green compact has been studied.

Abstract: The extruded microstructure and properties of Mg-2.7Nd-1.2Gd-0.4Zn-0.3Zr alloy by squeeze casting were investigated. After aging process (T5), the dislocation density was enhanced and the dislocation interaction was increased; the factors of grain refinement, RE phases redistribution, the increment of dislocations and the interaction between dislocations and precipitate phases were contributed to the strength increase after hot extrusion and aging treatment, the fracture mode of the hot-extruded alloy was the fracture of the secondary phases and the trans-grain fracture.

Abstract: Nonspherical mesoporous silica with banana-like morphology has been synthesized successfully through organic-inorganic cooperative interaction by adding the small molecules additives. SEM and TEM image revealed that the silica with banana-like morphology possess hexagonal pore channels and packed parallel to the long axis. XRD further confirmed the high ordered two dimensional (2-D) hexagonal (p6m) mesostructure. N2 adsorption-desorption measurement show that they have high BET surface area and large pore size and pore volume. Impressively, through vertical deposition assembly technique, the anisotropic nonspherical banana-like mesoporous silica can be organized into closely-packed monolayer and multilayer film, demonstrating potential application in photonics, electronics and magnetics.

Abstract: In this paper, the relationship between gel content and drying shrinkage has been investigated. The drying shrinkage for different specimens was tested by comparator. Modified Water Absorption Method was used in the semi-quantitative analysis of gel content. Found that (1) The sample, which is high in activity, produces more gel, so does the drying shrinkage. (2) The drying shrinkage is linear correlation with gel content. (3) Sample with higher gel content has thinner pore structure.

Abstract: Porous ZnO microtubes have been synthesized via a facile hydrothermal method based on nanoparticle splicing growth and the preferential etching strategy in the hydrothermal reaction system with high supersaturation. The ZnO tubes have hexangular wurtzite structure with a dimension of about 6 to 12 m in length, 4 m in diameter and about 40 nm in wall thickness, which is made of numerous mesopores with diameter ranging from 40 nm to 200 nm.

Abstract: A series of NH₄Y₃F₁₀ sub-microcrystals had been prepared by a one-step hydrothermal route. The morphological and structural properties of the sub-microcrystals were studied by scanning electron microscopy (SEM) and powder X-ray diffraction (XRD). The results of SEM and XRD suggested that NH₄Y₃F₁₀ sub-microcrystals have irregular shapes with their sizes varying from 100nm to 500nm and the structures of obtained NH₄Y₃F₁₀ sub-microcrystals are cubic phase. Additionally, the down-converting(DC) phenomenon have been observed under UV excitation in (Yb³⁺, Nd³⁺) co-doped NH₄Y₃F₁₀. It is found that luminescent efficiency of 10%Yb, 1%Nd co-doped NH₄Y₃F₁₀ sub-microcrystals is stronger than that of 10%Yb, 5%Nd co-doped NH₄Y₃F₁₀ sub-microcrystals. The energy transfer mechanism of the emission spectra of (Yb³⁺, Nd³⁺) co-doped NH₄Y₃F₁₀ is discussed.

Abstract: Fe-Mn composite oxide has been successfully synthesized using manganese ore in Guilin, Guangxi as an effective way to dephosphorize by acid leaching. Studied about the optimum conditions of acid leaching and the dephosphorization of Fe-Mn composite oxide. Process of the sulfuric acid concentration 2.1mol/L, solid-liquid ratio 1:4, reaction time 3.5h, the reaction temperature 90°C, the iron leaching rate of 66% while manganese 93%. Adsorption of phosphorus experiments showed that at oxide dosage 0.1000g, the reaction temperature 20°C, the reaction time 60min, pH 3.0, the phosphorus mass concentration 500ug/L in water sample, the phosphorus removal rate was up to 98.65%, compared to 70% removal rate of 0.5000g natural ore. The comparison of adsorption isotherms between Fe-Mn composite oxide and natural ore showed that in above conditions, the oxide's saturation adsorption quantity was 5.0000mg/g, improved 36.99 times.