The crystal structure, morphology, and galvanostatic cycling and rate performances of cobalt-substituted Li 2 MnSiO 4 /C compounds, Li 2 Mn 1−x Co x SiO 4 /C (x = 0.25, 0.5, and 0.75), were evaluated and compared with those of Li 2 MnSiO 4 /C and Li 2 CoSiO 4 /C. Li 2 Mn 1−x Co x SiO 4 /C (x = 0.25, 0.5, and 0.75) compositions comprising uniform nanosized primary particles and no impurities were successfully synthesized using a hydrothermal method, followed by carbon coating. In addition, Li 2 MnSiO 4 /C and Li 2 CoSiO 4 /C were synthesized for comparison. The synthesized Li 2 Mn 1−x Co x SiO 4 /C (x = 0.25, 0.5, and 0.75) were solid solutions and were identified using an orthorhombic unit cell with Pmn2 1 space group symmetry. Although the capacity fades for Li 2 Mn 1−x Co x SiO 4 /C were similar to those for Li 2 MnSiO 4 /C, the discharge capacity, average discharge voltage and rate capability of Li 2 MnSiO 4 / C improved when Co was substituted for Mn. Li 2 Mn 0.25 Co 0.75 SiO 4 /C exhibited the best electrochemical performance with first energy density of 659.7 Wh kg −1 which was greater than that of LiMn 2 O 4 (500 Wh kg −1) and LiNi 1/3 Co 1/3-Mn 1/3 O 2 (600 Wh kg −1). The good electrochemical performance of Li 2 Mn 0.25 Co 0.75 SiO 4 /C is attributed to its lower charge transfer resistance relative to that of Li 2 MnSiO 4 /C.

Crystallographic and morphological data and the galvanostatic cycling and rate performance of the cobaltsubstituted Li 2 Fe 0.5 Mn 0.5

PtRh/CeO 2 /Al 2 O 3 was successfully synthesized by the hydrothermal method, and its chemical and physical properties as well as its catalytic activity were evaluated. PtRh/CeO 2 /Al 2 O 3 was also synthesized by the conventional impregnation method for purpose of comparison. PtRh/CeO 2 /Al 2 O 3 synthesized by the hydrothermal method comprised hollow CeO 2 nanorods coated with nanoparticle arrays that served as selective supports for Pt and Rh on CeO 2 surfaces. Although the lights-off temperatures of NO and C 3 H 6 were similar for PtRh/CeO 2 /Al 2 O 3 catalysts synthesized by the two methods, moreover, PtRh/CeO 2 /Al 2 O 3 synthesized by the hydrothermal method exhibited a lower lights-off CO temperature than that synthesized by the impregnation method. PtRh/CeO 2 /Al 2 O 3 synthesized by the hydrothermal method also exhibited better catalytic activity, which was attributed to its better dispersion of Pt and Rh than that synthesized by the impregnation method.

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Recently, huge amount of waste has been recycled in cement plant, and many kinds of aversive substances (chlorides, alkalies, sulfates and heavy metal salt) have been brought into cement manufacturing process with the wastes as raw materials. These substances are usually removed by chlorine bypass system from cement kilnpreheater, called as "K powder". Since cement plant is expected to use more wastes, "K powder" constituents should be separated with each other as recycled resources. In this study, we tried sulfidized flotation to separate lead components from "K powder" with the recovery of more than 60% by optimizing the flotation conditions, and clarify the reaction mechanism. As a result, we found the optimum conditions in case of 150 g/L pulp density of "K powder" as follows. 1) Adjust the initial pH of the pulp to 3.0 by sulfuric acid, 2) Take 30 min for aging of gypsum formation at the pH 3.0, 3) Add the NaHS of 20 g/kg-"K powder" and take 15 min for sulfidization, 4) Add the PAX of 3.2 g/kg-"K powder" and take 15 min for conditioning, 5) Readjust the pH to 3.0 ～ 4.0 by sulfuric acid and carry out flotation. We also found that the formation of K 2 Pb(SO 4) 2 during the conditioning causes the decrease of lead recovery in flotation and that the K 2 Pb(SO 4) 2 formation can be suppressed by limiting K + concentration in solution under 800 mmol/L and/or keeping the pulp temperature over 40℃ at the stage of NaHS addition. Then, we could separate lead components from "K powder" with the recovery of 60 % as a lead concentration of 10 ～ 30 Pb wt% under the same condition of sulfidized flotation for the "K powders" of various component.

Hollow Al2O3 microfibers were successfully synthesized via a novel hydrothermal method using cotton fiber as a template followed by annealing. The hollow Al2O3 microfibers annealed at 1200 °C for 5 h contained no impurity phases, and the Al2O3 composing the microfibers was confirmed to exhibit the trigonal unit cell of α-Al2O3 with R$\bar{3}$c space-group symmetry. The synthesized hollow Al2O3 microfibers were 5–15 µm in diameter, with walls 500–800 nm thick; the walls were composed of Al2O3 primary particles 100–200 nm in diameter. The specific heat capacity of the synthesized hollow Al2O3 microfibers was approximately the same as that reported in the literature for α-Al2O3. In addition, the annealing temperature of the hollow Al2O3 microfibers was studied to elucidate their mechanism of formation. The chemical and physical properties of the synthesized hollow Al2O3 microfibers indicate that they can be used as a thermal insulation material.

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