One-potN-alkylation of primary amines to secondary amines by gold clusters supported on porous coordination polymers

Gold clusters and nanoparticles were deposited on the three kinds of porous coordination polymers (PCP5), MOF-5, CPL-2, and AI-MIL53 by the solid grinding method. The size of Au particles depended on the kinds of PCPs and increased in the order of AI-MIL53 < CPL-2 < MOF-5. The mean diameter of Au particles supported on AI-MIL53 was estimated to be 1.6 nm by HAADFSTEM. Such small Au clusters on AI-MIL53 can catalyze one-pot synthesis of secondary amines from primary amines by sequential oxidation/hydrogenation owing to the remarkable improvement of hydrogenation efficiency of imine. Gold clusters deposited on AI-MIL53 can also promoteN-alkylation of amine with alcohol to form a secondary amine under N₂ atmosphere without using O₂ and H₂.     

X80级管线钢的生产和应用

介绍了日本JFE钢铁公司X80级和X100级管线钢中厚板(12．7～16．9mm)的合金设计原则，管线钢的焊接工艺设计和生产工艺流程，指出超冷却能力在线加速冷却工艺的优越性。系统分析了管线钢管的力学性能，冷展平取样方法因包申格效应形成的误差和钢管的现场环焊性能，并对JFE钢铁公司在X80级管线钢管方面的生产供货业绩做了介绍。     

ADTR-motor drive for electric vehicle

A new motor (ADTR-motor: Anti-Directional Twin Rotary Motor) for electric vehicle drive is proposed. A stator in a conventional motor is reformed to be movable, and the stator (outer rotor) and the rotor (inner rotor) rotate in anti-directions. The IM-type ADTR-motor and the SM-type ADTR-motor are considered, and in this paper a prototype of the IM-type ADTR-motor is constructed experimentally. When the ADTR-motor is used for an EV drive, the direction of one of the rotors should be reversed. Both rotors, when rotated in the same direction, propel the two wheels of EV. The torque of the wheels can be balanced without differential gear. The fundamental characteristics of ADTR-motor are clarified. The characteristics are the structure of ADTR-motor, the equivalent circuit parameters, the torque balance theory, the torque-speed characteristics, the rotor speed transient characteristics, and the transient response under the speed sensorless torque control.     

Immunohistochemical study of collagen in gastric cancer tissue

The distribution and localization of collagen types were studied immunohistochemically in resected tissues obtained from gastric cancer patients. The expression of transforming growth factor (TGF) -alpha, TGF-beta 1 and TGF-beta 2 on cancer cells as well as the aggregation of T lymphocytes in the cancer tissue were also studied, in order to determine the differences between differentiated and undifferentiated type cancer. The interstitial tissues of differentiated type cancer showed intense staining for types I and III collagen, while those of undifferentiated type cancer showed intense staining for types I and III collagen, in addition to the stronger staining for types IV, V and VI collagen. Characteristically, type IV collagen was intensely stained in the interstitium in 18 of 20 undifferentiated type cancer (90%), but was stained in only one of 15 differentiated type cancer (6%). CD 3+ T lymphocytes were aggregated in the interstitial tissue of both the tumors, where the density of CD 4+ cells and the ratio of CD 4 to CD 8 were significantly higher in undifferentiated type cancer than in differentiated type cancer. TGF-alpha was detected in cancer cells in 80% of the differentiated cases and in 45% of the undifferentiated cases. The staining of TGF-beta 1 was also detected in 80% of the undifferentiated cases, which was significantly higher than 47% in differentiated cases. There were no differences in the incidences of staining for TGF-beta 2 between differentiated (33%) and undifferentiated type cancer (40%). These results suggest that there exist different mechanisms in the regulation of collagen production between differentiated and undifferentiated types of gastric cancer.     

A study of a unit commitment problem with transmission constraints

Unit commitment problem is an optimization problem to determine the start‐up and shut‐down schedule of thermal units while satisfying various constraints, for example, generation‐demand balance, unit minimum up/down time, system reserve, and so on. Since this problem involves a large number of 0–1 type variables that represent up/down status of the unit and continuous variables expressing generation output, it is a difficult combinatorial optimization problem to solve. The study at present concerns the method for requiring the suboptimum solution efficiently. Unit commitment method widely used solves the problem without consideration of voltage, reactive power, and transmission constraints. In this paper, we will propose a solution of unit commitment with voltage and transmission constraints, based on the unit decommitment procedure (UDP) method, heuristic method, and optimal power flow (OPF). In this method, initial unit status will be determined from random numbers and the feasibility will be checked for minimum start‐up/shut‐down time and demand‐generation balance. If the solution is infeasible, the initial solution will be regenerated until a feasible solution can be found. Next, OPF is applied for each time period with the temporary unit status. Then, the units that have less contribution to the cost are detected and will be shut down based on the unit decommitment rules. This process will be repeated until suboptimal solution is obtained. The proposed method has been applied to the IEEE 118‐bus test system with 36 generating units with successful result. © 2003 Wiley Periodicals, Inc. Electr Eng Jpn, 144(3): 36–45, 2003; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.10187     

Sequential HAADF-STEM observation of structural changes in Au nanoparticles supported on CeO<Subscript>2</Subscript>

Sequential high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM) was used to clarify the detailed process of structural changes in Au/CeO₂ catalysts found in our previous TEM observations. The layer-by-layer shrinkage of a Au nanoparticle on CeO₂ during electron beam irradiation and recovery at the same position after switching off the beam were observed with clear resolution of Ce and Au atomic columns. Displaced Au atomic columns at the perimeter of the Au/CeO₂ interface during the electron beam irradiation have been analyzed using first-principles calculations, which indicate that such Au atoms at the perimeter edge are located above oxygen vacancies or Ce-terminated surface regions. The present behavior of Au atoms and nanoparticles provides valuable insights into the mechanisms of both structural changes and catalytic activity of Au/CeO₂ catalysts.     

Percolation Conduction in Hybrid Thermoelectric Material Consisting of Bi0.88Sb0.12 and Barium Ferrite Particles

A hybrid material consisting of thermoelectric Bi_0.88Sb_0.12 and Ba ferrite Bi_0.88Sb_0.12(BaFe₁₂O₁₉) _x (x = 0, 0.025, 0.04, and 0.08) was synthesized using sintering. Powder x-ray diffraction patterns and scanning electron microscopy images of the hybrid indicate that the BaFe₁₂O₁₉ particles were well distributed in the host Bi_0.88Sb_0.12 phase. The temperature dependence of the electrical resistivity ρ of the host Bi-Sb exhibits metallic behavior. By the addition of Ba ferrite particles, the ρ at 300 K increases intensively, and ρ(Τ) then behaves similarly to a semiconductor. However, it is noted that the thermoelectric power S is unchanged. Inhibition of current and heat flows by a restricted conduction path and the unchanged electromotive force generated by the Seebeck effect in the conduction path can be understood based on a site-percolation model consisting of conducting Bi-Sb and insulating Ba ferrite. The critical volume fraction p _c of this system was estimated experimentally as p _c = 0.68.     

Fabrication of titanate nanowires with different dimensions

Titanate nanowires were fabricated by the reaction of titania particles in a highly concentrated KOH aqueous solution at 150 °C for more than 20 h followed by the rinsing of the resultant compound with a 0.1 M HCl aqueous solution and purified water. The diameter and length of the titanate nanowires can be controlled by using titania powders with different crystalline phases and particle sizes. The crystalline phase in the titanate nanowire was considered to be a hydrated titanate.