鞋履奇才Michel Perry的梦想庄园

Voudenay庄园位于著名的葡萄酒故乡——法国勃艮第(Bourgogne),建造于十八世纪,周围风景如画,一派诗情画意。这座美丽的庄园曾经破败不堪,仿如废墟,但被鞋履设计师Michel Perry购买、翻修后又重现生机。Michel Perry夫妇是在无意间发现Vaudenay庄园的,故事开始说     

Crosslinked polyethers as media for ionic conduction

A broad outline is given of a comprehensive investigation dealing with solid polymeric electrolytes containing ionic species. These materials are based on various types of polyethers (homopolymers, block and graft copolymers) crosslinked via urethane chemistry and either filled with a salt or transformed into ionomers with the anions attached to the chains. The properties studied were specific volume, swelling, glass transition temperature, viscoelasticity, ionic conductivity, transport numbers, magnetic relaxation of nuclei from both the polymer chains and the ions, and redox stability. Mechanisms and models are proposed to explain chain partitioning by cations and the mode of ionic transport. An all-solid-state battery was prepared with one of these materials to prove its good performance.     

Comments on: Deville and Särndal’s calibration: revisiting a 25 years old successful optimization problem

TEST - We provide a brief discussion on the development of model calibration techniques and optimal calibration estimation in survey sampling and its relation to Deville and Särndal’s...     

Experimental and DFT studies of N2O decomposition over bare and Co-doped magnesium oxide—insights into the role of active sites topology in dry and wet conditions

Isothermal and TPSR studies of deN₂O reaction were performed over model MgO, and Co–MgO systems. Complementary experiments such as O₂-TPD, H₂O-TPD and IR, supported by DFT molecular modeling were carried out to elucidate the role of topological irregularities such as corners, steps, edges on the principal reaction events in dry and wet environment. The hydroxyl groups produced upon water adsorption were used for selective blocking of the active sites. Topological aspect of the surface reactivity was discussed in terms of the energetics of reaction steps and the relative stability and mobility of reaction intermediates (O₂²⁻) and inhibiting (OH⁻_surf) species. Whereas the most active corner sites are depleted by oxygen, produced in the course of N₂O decomposition, the edge and step sites could be eliminated only by more strongly adsorbed water. In steady state conditions the reaction turns over mainly on terrace sites and is moisture insensitive. Upon introduction of Co²⁺ ions to magnesium oxide the N₂O conversion curve is shifted by 200 °C towards lower temperatures, due to the change in the N₂O activation step (from anionic redox to cationic redox). However, at such thermal conditions the terrace sites remain still hydroxylated, and the overall reaction rate is clearly deteriorated by water present in the feed.     

Étude et réalisation de modulateurs et de démodulateurs directs quadriphases pour la régénération à bord des satellites relais

This paper presents the study of a four phase remodulation demodulator which is part of a microwave signal regenerator for communications payload or data relay satellites. At first, 3.87 GHz biphase (bpsk) balanced modulator has been produced, using planar technology with slotlines and microstrip lines engraved on an Epsilam-type substrate, and two beam-lead Schottky diodes. Under modulation, carrier and even harmonic rejection of better than 50 dB is obtained, with insertion losses lower than 2 dB. A fourphase (qpsk) modulator is also produced using two bpsk modulators. Each phase state is achieved at ± 1.3° with 5.2 dB of insertion losses and a residual amplitude modulation of ± 0.14 dB. Carrier and even harmonic rejection of 45 dB is obtained.     

Kinetic Study of CO2 Reforming of Propane over Ru/Al2O3

The rate of reaction of propane over a Ru/Al₂O₃ catalyst was determined as a function of the partial pressures of the reactants, C₃H₈ and CO₂ at 600 and 650°C. The order of the reaction was found to be fractional with respect to carbon dioxide, indicating its involvement in the rate-determining step of the reaction. The order of the reaction was zero in propane indicating the fast reaction of propane over the catalyst. The apparent activation energies for propane and the formation of hydrogen and carbon monoxide were investigated. Values for the formation of hydrogen and carbon monoxide indicated a decrease in the CO:H₂ ratio with an increase in temperature. Modelling of the kinetic data was inconclusive in the selection of a possible mechanism as good fits were observed for a Langmuir–Hinshelwood and a Mars–van Krevelen mechanism.