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排序方式: 共有188条查询结果,搜索用时 93 毫秒
61.
De Lazari Ferreira Luiza Calado Hállen Daniel Rezende 《Journal of Solid State Electrochemistry》2018,22(5):1507-1515
Journal of Solid State Electrochemistry - Polythiophenes are conjugated polymers that are highly promising candidates for use as an active layer in flexible optoelectronic devices. The... 相似文献
62.
63.
Maíra N. de Almeida Valéria M. Guimarães Daniel L. Falkoski Guilherme B. T. Paes José Ivo Ribeiro Jr. Evan M. Visser Rafael F. Alfenas Olinto L. Pereira Sebastião T. de Rezende 《Applied biochemistry and biotechnology》2014,172(3):1332-1346
Enzymatic hydrolysis is an important but expensive step in the production of ethanol from biomass. Thus, the production of efficient enzymatic cocktails is of great interest for this biotechnological application. The production of endoglucanase and xylanase activites from F. verticillioides were optimized in a factorial design (25) followed by a CCDR design. Endoglucanase and xylanase activities increased from 2.8 to 8.0 U/mL and from 13.4 to 114 U/mL, respectively. The optimal pH and temperature were determined for endoglucanase (5.6, 80 °C), cellobiase (5.6, 60 °C), FPase (6.0, 55 °C) and xylanase (7.0, 50 °C). The optimized crude extract was applied in saccharification and fermentation of sugarcane bagasse from which 9.7 g/L of ethanol was produced at an ethanol/biomass yield of 0.19. 相似文献
64.
In this article we obtain a duality result for an n-manifold N with boundary ∂N = N + ⊔N
−
a disjoint union, where N
+ and N
−
are arbitrarily chosen parts in ∂N and need not be compact. This duality result is used to generalize the Poincaré–Hopf inequalities in a non-compact setting. 相似文献
65.
Nie L Lavinder JJ Sarkar M Stephany K Magliery TJ 《Journal of the American Chemical Society》2011,133(16):6177-6186
A general combinatorial mutagenesis strategy using common dimethoxytrityl-protected mononucleotide phosphoramidites and a single orthogonally protected trinucleotide phosphoramidite (Fmoc-TAG; Fmoc = 9-fluorenylmethoxycarbonyl) was developed to scan a gene with the TAG amber stop codon with complete synthetic control. In combination with stop-codon suppressors that insert natural (e.g., alanine) or unnatural (e.g., p-benzoylphenylalanine, Bpa) amino acids, a single DNA library can be used to incorporate different amino acids for diverse purposes. Here, we scanned TAG codons through part of the gene for a model four-helix bundle protein, Rop, which regulates the copy number of ColE1 plasmids. Alanine was incorporated into Rop for mapping its binding site using an in vivo activity screen, and subtle but important differences from in vitro gel-shift studies of Rop function are evident. As a test, Bpa was incorporated using a Phe14 amber mutant isolated from the scanning library. Surprisingly, Phe14Bpa-Rop is weakly active, despite the critical role of Phe14 in Rop activity. Bpa is a photoaffinity label unnatural amino acid that can form covalent bonds with adjacent molecules upon UV irradiation. Irradiation of Phe14Bpa-Rop, which is a dimer in solution like wild-type Rop, results in covalent dimers, trimers, and tetramers. This suggests that Phe14Bpa-Rop weakly associates as a tetramer in solution and highlights the use of Bpa cross-linking as a means of trapping weak and transient interactions. 相似文献
66.
M. F. S. Rezende R. A. Mansur H. -D. Pfannes A. I. C. Persiano 《Hyperfine Interactions》1991,66(1-4):319-323
Two distinct phases of the Fe?Co?Nb and three of the Fe?Co?V systems have been studied by means of X-ray diffraction and Mössbauer spectroscopy. The dependence of the lattice parameter of the alpha phase on the nominal solute content in equiatomic FeCo together with the alterations of the Mössbauer spectra have shown a very limited solubility of niobium in alpha FeCo. There are indications that the solubility of vanadium in alpha FeCo increases with increasing nominal content of solute in the alloy. A mechanism involving the withdrawal of cobalt from the alpha matrix to form a phase rich in Co and V (gamma) is proposed to explain such a varying solubility. The vanadium content of the sigma phase in equiatomic FeCo alloys with 22 wt% V is proposed to be less than 50 at%. 相似文献
67.
The possibility to excite ferromagnetic magnons with very large k is analyzed theoretically. The proposed excitation mechanism is analogous to the first-order Suhl instability and takes place via non-linear processes involving localized modes associated with imputities in ferromagnetic insulators. A rough estimate of the critical power of a far-infrared laser source necessary to attain the instability threshold shows that the processes are experimentally feasible. 相似文献
68.
Jorge Rezende 《Letters in Mathematical Physics》1983,7(1):75-83
We give a simple proof of Feynman's formula for the Green's function of the n-dimensional harmonic oscillator valid for every time t with Im t ≤ 0. As a consequence the Schrödinger equation for the anharmonic oscillator is integrated and expressed by the Feynman path integral on Hilbert space. 相似文献
69.
In this work, the influence of polyaniline (PAni) doped with both camphorsulfonic acid (PAni‐CSA) and dodecylbenzenesulfonic acid (PAni‐DBSA) on polyurethane (PU)/PAni blends was studied by rheological and morphological analyses. The effect of doped polyaniline on the attenuation of incident microwave radiation, in the frequency range from 8.0 to 12.0 GHz, was also investigated. The complex viscosity (η*) of PAni‐DBSA blends is observed to vary more significantly as a function of resting time than PAni‐CSA blends. This behavior is attributed to a better dispersion of PAni particles into the matrix on account of the presence of smaller agglomerates, as observed by optical and electron microscopy. However, this behavior has not been determinant on microwave absorption by the blends, with those that contain PAni‐CSA showing higher attenuation values. Copyright © 2007 John Wiley & Sons, Ltd. 相似文献
70.
R. L. O. Rezende M. I. R. M. Santoro J. R. Matos 《Journal of Thermal Analysis and Calorimetry》2008,93(3):881-886
This paper demonstrates the application of thermal analysis in compatibility and stability studies between an ACE inhibitor
(enalapril maleate) and excipients. The results have helped to elucidate the reason of a stability problem observed during
the storage of enalapril maleate tablets. Incompatibility between enalapril maleate and colloidal silicon dioxide was detected.
Besides, it was confirmed that the reaction between enalapril maleate and NaHCO3 increases the thermal stability of the drug. This study supports the importance of using thermoanalytical methods in the
development of pharmaceuticals. 相似文献