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排序方式: 共有385条查询结果,搜索用时 78 毫秒
1.
Application of TiO2-nanotubes/PbO2 as an anode for the electrochemical elimination of Acid Red 1 dye
Santos José Eudes L. de Moura Dayanne Chianca da Silva Djalma Ribeiro Panizza Marco Martínez-Huitle Carlos A. 《Journal of Solid State Electrochemistry》2019,23(2):351-360
Journal of Solid State Electrochemistry - In this study, galvanostatic electrolysis, through the use of the platinum supported on Ti (Ti/Pt) and Ti/TiO2-nanotubes/PbO2 anodes, was conducted in an... 相似文献
2.
Ana Luísa Daniel‐da‐Silva João Carlos Moura Bordado José Miguel Martín‐Martínez 《Journal of Polymer Science.Polymer Physics》2007,45(22):3034-3045
The degree of phase separation in several moisture‐cured poly(urethane urea)s (PUUs) was studied by FTIR spectroscopy, wide angle X‐ray diffraction (WAXD), and temperature‐modulated differential scanning calorimetry (TMDSC). This latter technique was shown to be particularly useful in analysing the degree of phase separation in PUU polymers. Both phase mixing and phase segregation coexisted in the PUUs and the degree of phase separation increased as the urea hard segment (HS) content in the PUU increased. The maximum solubility of urea HSs into the polyol soft segments (SSs) was achieved for 50 wt % urea HS content in diol‐based PUUs, whereas for triol‐based PUUs the highest solubility between HS and SS was reached for lower urea HS amount. Finally, the higher the urea HS content the higher the extent of phase separation in the PUU. © 2007 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 45: 3034–3045, 2007 相似文献
3.
Claire Moura 《Proceedings of the American Mathematical Society》2004,132(3):687-690
We determine the maximum punctual order of contact between two plane algebraic curves, of which one is reduced. We prove that, generically on the reduced curve, this quantity is always strictly bounded by the product of the degrees of the curves.
4.
This research was aimed
to investigate the role of clay on the combustion and kinetic behavior of
crude oils in limestone matrix. For this purpose, simultaneous TG (thermogravimetry)
and DTA (differential thermal analysis) experiments were performed at three
different heating rates as 10–15 and 20°C min–1,
respectively. A uniform trend of decreasing activation energies was observed
with the addition of clay. It was concluded that clays surface area affects
the values of Arrhenius constant, while it is the catalytic properties of
clay, which lower the activation energies of all the reactions, involved in
the combustion process. 相似文献
5.
Elizabeth Nunes Fernandes Mariele Nair de Campos Moura Jos Luis F. Costa Lima Boaventura F. Reis 《Microchemical Journal》2004,77(2):107-112
An automatic flow procedure for the determination of glycerol in wines by employing a flow system based on multicommutation and enzymatic reaction is described. Glycerol dehydrogenase was immobilized on aminopropyl glass beads and packed into a column that was coupled to the flow system. The NADH produced by the enzymatic reaction was monitored by spectrophotometry at 340 nm and its radiation absorption presented a relationship with glycerol concentration. The system manifold comprised a set of three-way solenoid valves controlled by a microcomputer, which was furnished with electronic interfaces and runs a software that was designed to carry out on-line sample dilution, reagent addition, and data acquisition. The procedure allows the determination of glycerol in wine samples without any prior pretreatment. The procedure presented as profitable features a linear response range between 2.0 and 10.0 g l−1 glycerol (R=0.998), a detection limit of 0.006 g l−1 glycerol, a relative standard deviation of 1.8% (n=14) for a typical wine sample presenting 5.3 g l−1 glycerol, a sampling throughput of 33 determinations per hour, and a NAD+ consumption of 0.8 mg per determination. The results were compared with those obtained using a reference method and no significant difference at 90% confidence level was observed. 相似文献
6.
Fernandes L. P. Éhen Zs. Moura T. F. Novák Cs. Sztatisz J. 《Journal of Thermal Analysis and Calorimetry》2004,78(2):557-573
Thermoanalytical techniques, being rapid and un-expensive have been used for the investigation of the cyclodextrin inclusion
complexes for three decades. The conventional thermoanalytical techniques (TG and DTA/DSC) follow the thermal properties of
the uncomplexed compounds. Consequently, the inclusion complex formation as well as the liberation of the entrapped guest
cannot be followed. Monitoring the products of the thermal fragmentation of parent cyclodextrin and the included molecule(s),
applying TG-MS combined technique provides evidence concerning the inclusion complex formation, and besides, gives selective
signal to follow the decomposition of the cyclodextrin inclusion complexes. b-cyclodextrin inclusion complexes of Thymol and
Lippia sidoides Cham essential oil extract have been prepared and investigated using conventional and combined (TG-MS) thermoanalytical techniques.
The evolved gas analysis proved the inclusion complex formation between the host and guests. By the evaluation of the experimental
results the elaboration of the entrapped guests from the cyclodextrin cavity could be followed.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
7.
The reaction of di-p-tolyltelluride with ferric, cupric and mercuric chloride, performed in glacial acetic acid, effects the reduction of the metallic salts giving rise to di-p-tolyltellurium dichloride. In toluene solution only the ferric chloride was reduced and the anhydride of di-p-tolyltellurium hydroxychloride formed, due to the hydrolysis of the tellurium dichloride. The reaction of the mentioned telluride and benzoyl chloride gave rise to a mixture of the dichloride and the dibenzoate. The mechanism of this reaction is discussed. 相似文献
8.
Auchère F Raleiras P Benson L Venyaminov SY Tavares P Moura JJ Moura I Rusnak F 《Inorganic chemistry》2003,42(4):938-940
Superoxide reductases catalyze the monovalent reduction of superoxide anion to hydrogen peroxide. Spectroscopic evidence for the formation of a dinuclear cyano-bridged adduct after K(3)Fe(CN)(6) oxidation of the superoxide reductases neelaredoxin from Treponema pallidum and desulfoferrodoxin from Desulfovibrio vulgaris was reported. Oxidation with K(3)Fe(CN)(6) reveals a band in the near-IR with lambda(max) at 1020 nm, coupled with an increase of the iron content by almost 2-fold. Fourier transform infrared spectroscopy provided additional evidence with CN-stretching vibrations at 2095, 2025-2030, and 2047 cm(-)(1), assigned to a ferrocyanide adduct of the enzyme. Interestingly, the low-temperature electronic paramagnetic resonance (EPR) spectra of oxidized TpNlr reveal at least three different species indicating structural heterogeneity in the coordination environment of the active site Fe ion. Given the likely 6-coordinate geometry of the active site Fe(3+) ion in the ferrocyanide adduct, we propose that the rhombic EPR species can serve as a model of a hexacoordinate form of the active site. 相似文献
9.
Theodoro T. R. Moura J. O. V. Dias J. R. Carpegiani J. A. Godoy W. M. Aguiar L. G. 《Kinetics and Catalysis》2021,62(1):188-195
Kinetics and Catalysis - The production of sulfonated resins is of great interest to be applied in different industrial processes such as esterification, etherification, biodiesel production and... 相似文献
10.