排序方式: 共有79条查询结果,搜索用时 46 毫秒
71.
Structural Chemistry - Density functional theory calculations were carried out to study the degradation mechanism of anticancer drug carmustine in an aqueous medium. The calculations indicate that... 相似文献
72.
Shiri Farshad Norouzibazaz Mohammadsaleh Yari Ako Taherpour Avat 《Structural chemistry》2018,29(5):1465-1474
Structural Chemistry - Semustine as an anti-cancer medicine is decomposed by hydrolysis under pH-dependent conditions, forming chlorocarbonium ion and interaction with nucleic acid molecules. This... 相似文献
73.
Hemati Niloofar Shiri Farshad Hadidi Saba Mohammadi Elham Parvizi Rasool Hosein Farzaei Mohammad 《Structural chemistry》2021,32(3):1053-1060
Structural Chemistry - The antibiotic para-aminosalicylic acid (PAS) is decomposed into its decarboxylated product, meta-aminophenol, with a series of toxicity symptoms including hemolytic anemia.... 相似文献
74.
Nahid Soltani Firooz Reza Panahi Babak Mokhtarani Farshad Yazdani 《Cellulose (London, England)》2017,24(3):1407-1416
Tyrosinase is used to eliminate phenolic compounds from wastewater. Therefore, its immobilization is important to enhance catalytic efficiency. Papery materials are of particular interest for use as support for enzyme immobilization since the porous microstructure of fiber networks in papers can provide a suitable reaction environment, especially in flow-type catalytic reactions. However, immobilization of protein onto papery structure needs chemical modifications in severe conditions. To overcome this challenge, a cellulosic paper was directly amine-functionalized in moderate conditions and used for tyrosinase immobilization. The support was pretreated with HCl (0.5 N) solution and then sequentially immersed in ethylenediamine (EDA), glutaraldehyde solution (2% v/v) and the crude enzyme. In comparison with the untreated one, the immobilized enzyme on the EDA-treated support offered a 3.7-fold increase in activity. The FTIR spectra as well as EDX analysis proved the presence of amine groups in the cellulosic paper and also covalent immobilization of tyrosinase on the modified support. When considering the effect of pH on the activity at 25 °C, a maximum relative activity of 134% at pH 6 was revealed. Similarly, evaluating the effect of temperature on the activity at pH 7 displayed a maximum relative activity of 152% at 35 °C. The immobilized enzyme was suitable for use for more than four cycles to degrade a phenolic compound at severe pH and temperature conditions. Additionally, the immobilized enzyme was active after treatment of the surface at different pHs and temperatures for 105 min. The chemically modified cellulosic paper can be used as a support for enzyme immobilization. 相似文献
75.
Ali Nakhaei Pour Mohammad Reza Housaindokht Farshad Torabi 《Journal of the Iranian Chemical Society》2014,11(6):1639-1648
The kinetic parameters of water–gas shift (WGS) reaction in the Fischer–Tropsch synthesis (FTS) on lanthanum-promoted iron catalyst are analyzed by size-dependent thermodynamic method. A Langmuir–Hinshelwood kinetic equation is considered for the catalysts activity evaluation. A series of unsupported iron catalysts with different particle sizes are prepared via microemulsion method. These results show that the iron particle size has considerable effects on reactants adsorption and WGS kinetic parameters and WGS activity pass from a maximum by increasing the catalyst particle size. Finally, the analysis of data showed that by increasing the iron particle from 14 to 41 nm, the WGS activation energies and heats of adsorption of carbon monoxide and water on catalysts increased from 68 to 83, 22 to 28 and 75 to 94 kJ/mol, respectively. 相似文献
76.
N. Rezaiean H. A. Khonakdar P. Jafary S. M. A. Jafari R. Ghorbani 《Journal of Macromolecular Science: Physics》2016,55(10):1022-1038
Nanocomposites of polypropylene (PP) containing various contents of Cloisite 15A nanoclay particles were prepared by one-step melt compounding in a twin screw extruder. Tensile and impact properties of the nanocomposite systems were investigated and correlated with their microstructures. The tensile modulus increased with an increase in Cloisite 15A content but the tensile strength, elongation at break, and impact strength were decreased. WAXS and TEM studies showed almost exfoliated structures. There was a decrease in permeability values with an increase in nanoclay content up to 5 wt. %. Exceeding this content of nanoclay had no significant effect on permeation due to the aggregation phenomenon at high concentrations of the nanoparticles. Most of the examined micromechanical models for prediction of the tensile modulus of the nanocomposite were successful despite being based on fiber-shaped fillers. An exfoliated structure of clay within the nanocomposite was assumed for the modeling using a molecular dynamics simulations approach, employing Dreiding, Forcite, and COMPASS force fields, in order to investigate the best one for a successful estimation of elastic modulus. Relative to the experimental modulus values of the nanocomposites, which were around 1100–1200 MPa, the COMPASS force field had the best correlation with the values with a slight departure of about 10%. 相似文献
77.
Farshad Sohbatzadeh Mohsen Rabbani Mahboubeh Ghalandari 《Optics Communications》2012,285(13-14):3191-3194
In this paper, we numerically investigate the relativistic self-focusing of laser beam with LG01 mode in plasmas. An effective potential is introduced to identify the critical power. Numerical methods are employed to solve the governing equations. To verify the numerical procedures, we compare the known analytical solution of the relativistic critical power for TEM00 mode with our numerical method. It is shown that there is a good agreement between our numerical results and the analytical solution. The critical power for relativistic self-focusing of a LG01 laser beam is about 6 times of that for a TEM00 laser beam. 相似文献
78.
M. Farshad 《Journal of sound and vibration》1977,53(2):165-171
The problem of dynamic lateral-torsional instability of circular arches acted upon by generally non-conservative forces is treated herein. The influence of motion-dependency of loading on the stability characteristics is determined in certain cases. It is also found that a semi-circular arch which is only capable of rigid-mode-buckling according to static analysis may lose its stability through non-rigid modes if the dynamic criterion is utilized. 相似文献
79.
Journal of Solid State Electrochemistry - Vanadium oxide film electrodes synthesized by layer-by-layer assembly using sol–gel spin casting and variable 3 & 1 h annealing... 相似文献