排序方式: 共有23条查询结果,搜索用时 15 毫秒
1.
Haleh Kangarlou Arash Abdollahi Maryam Motallebi Aghgonbad 《Optics and Spectroscopy》2012,113(3):321-326
Zinc sulfide nano layers were deposited on glass substrates at 300 K by physical vapor deposition method, under high vacuum conditions and different deposition angles. Thickness of the layers were measured 73 nm, by quartz crystal method. Optical reflectance and transmittance of the layers were measured in the wave length of 300?C1100 nm. Optical constants were calculated by Kramers-Kronig relations. The influence of deposition angle in optical properties of ZnS nano layers are investigated. By using Generalized Gradient Approximations in context of plane wave pseudo-potentials (norm conserving and Ultrasoft) and full-potential linearized augmented plane wave methods, Band structure calculated and compared with experimental results. Possible energy transitions are also reported. 相似文献
2.
Ali Akbarzadeh Seyed Omid Ranaei Siadat Mostafa Motallebi Mohammad Reza Zamani Mohammad Barshan Tashnizi Sakineh Moshtaghi 《Applied biochemistry and biotechnology》2014,172(4):2253-2265
Bioconversion of cellulosic material into glucose needs cellulase enzymes. One of the most important organisms that produces cellulases is Trichoderma reesei, whose cellulose enzymes are probably the most widely used in the industry. However, these enzymes are not stable enough at high pH and temperatures. The optimized synthetic endoglucanase II gene with Pichia pastoris codon preferences was secretary expressed in P. pastoris. Recombinant enzyme characterization showed maximum activity at pH 4.8 and temperature 75 °C, and it demonstrated increasing thermal stability in high temperature. The enzyme maintained its activity in a wide pH range from 3.5 to 6.5. The optimization of fermentation medium was carried out in shaking flasks. Recombinant protein expression at optimum conditions (pH 7, temperature 25 °C, and 1 % methanol induction) for 72 h demonstrated 2,358.8 U/ml endoglucanase activity units. To our knowledge, this is the highest acidic thermophilic endoglucanase activity that is reported in crude intracellular medium in P. pastoris. We conclude that P. pastoris is an appropriate host for high-level expression of optimized endoglucanase gene with improved thermal stability. 相似文献
3.
Fakhari Amir Hossein Shafaghat Rouzbeh Jahanian Omid Ezoji Hossein Motallebi Hasankola Seyed Sadegh 《Journal of Thermal Analysis and Calorimetry》2020,139(4):2455-2464
Journal of Thermal Analysis and Calorimetry - Due to global concerns about the emissions, limited hydrocarbon fuel resources and high fuel prices, a lot of researches have been done to improve the... 相似文献
4.
Positivity - Using the coarsest weak topologies, we present the necessary and sufficient conditions for the weak upper, lower and symmetric compactness of subsets in cones. This leads us to... 相似文献
5.
Reaction of the carbanions derived from chloromethyl phenyl sulfone or 1 -chloroethyl phenyl sulfone with the cationic [Fe(arene)Cp] complexes 8 or 9 produced isolable c-adducts 10-12 . Attempted base induced elimination of the s?-adducts, which would have led to products of vicarious nucleophilic substitution (VNS reaction), failed. Similarly, no VNS products were obtained, when the (arene)tricarbonylchromium complexes 4 were reacted with the anion of chloromethyl phenyl sulfone. 相似文献
6.
The RhII-catalyzed decomposition of β,γ-unsaturated diazo ketones 1 in the presence of MeOH leads via vinylogous Wolff rearrangement to γ,δ-unsaturated esters 6 (Schemes 1 and 2). A modest asymmetric induction is achieved when the reaction is carried out with chiral tetrakis(pyrrolidinecarboxylato)- or tetrakis(oxazolidinonato)dirhodium(II) complexes. Vinyl and phenyl diazoacetates 11 and 20 , respectively, or 1-diazo-3-phenyl-propan-2-one ( 25 ), when subjected to the same reaction conditions, react by OH insertion with MeOH (Schemes 3–5). In the absence of MeOH, phenyl diazoacetates 20 and 25 undergo intramolecular CH insertion to 22 and 26 , respectively. Intramolecular CH insertion occurs with N-aryldiazoamides 23 even in the presence of MeOH (Scheme 5). 相似文献
7.
Titanium layers with different thicknesses of 21, 83.7, and 133 nm and same other deposition conditions were deposited on glass substrates at 300 K, by physical vapor deposition method under high vacuum conditions. The optical reflectance of the layers was measured in the wave length range of 400–800 nm. The optical properties were calculated by using Kramers-Kronig relations. Relation between the optical properties and nanostructure of the layers was investigated. By using Generalized Gradient Approximations in context of plane wave pseudopotentials (norm conserving and ultrasoft) method, band structure calculated and compared with experimental results. 相似文献
8.
Motallebi Hasankola Seyed Sadegh Shafaghat Rouzbeh Jahanian Omid Nikzadfar Kamyar 《Journal of Thermal Analysis and Calorimetry》2020,139(4):2509-2516
Journal of Thermal Analysis and Calorimetry - Nowadays, due to the environmental problems caused by pollution and high fossil fuels prices, the study on the internal combustion engines have... 相似文献
9.
Guang Wang Steve Leclair Luise-Andree Roy Shahrokh Motallebi Yue Zhao 《Liquid crystals》2005,32(1):125-131
A liquid crystalline dimethacrylate-based monomer containing an azobenzene group was synthesized. The miscibility of the azo monomer and its crosslinked polymer network with ferroelectric liquid crystals (FLCs) was improved by the liquid crystallinity of the monomer. By performing thermal polymerization of the azo monomer dissolved in a FLC host under linearly polarized visible light irradiation, following a pre-irradiation with unpolarized UV light at room temperature, bulk alignment of the FLC could be induced in the absence of surface orientation layers, as a result of the photo-orientation of azobenzene moieties related to the reversible trans-cis photoisomerization of the chromophore. The optical and rubbing-free alignment of a FLC could be achieved with as few as 0.5 wt % of the azo polymer network. This represents a step toward the preparation of uniform samples of photoaligned FLC by reducing the amount of the azo polymer network that may be phase-separated from the FLC host. 相似文献
10.
A single linearly polarized irradiation was used to initiate cationic photopolymerization of an azobenzene-containing diepoxide monomer dissolved in a ferroelectric liquid crystal (FLC) and, at the same time, to induce fast trans-cis-trans photoisomerization cycles for the azobenzene chromophore which leads to a bulk alignment of the FLC in the absence of surface orientation layers. The spectral output of the light source is required to have separate UV and visible wavelengths, which allow for simultaneous photopolymerization of the monomer and photoalignment of the chromophore. Photopolymerization was allowed to take place in different phases of the FLC to reveal the effects on the FLC photoalignment; the interaction between the anisotropic azobenzene polymer network and the FLC host was also investigated using polarizing UV-Vis spectroscopy. 相似文献