排序方式: 共有93条查询结果,搜索用时 31 毫秒
1.
Bahraminasab A. Tabei S. M. A. Masoudi A. A. Shahbazi F. Reza Rahimi Tabar M. 《Journal of statistical physics》2004,116(5-6):1521-1544
The joint probability distribution function (PDF) of the height and its gradients is derived for a zero tension d + 1-dimensional Kardar-Parisi-Zhang (KPZ) equation. It is proved that the height's PDF of zero tension KPZ equation shows lack of positivity after a finite time t c . The properties of zero tension KPZ equation and its differences with the case that it possess an infinitesimal surface tension is discussed. Also potential relation between the time scale t c and the singularity time scale t c.v→0 of the KPZ equation with an infinitesimal surface tension is investigated. 相似文献
2.
Amirhossein Nazhand Alessandra Durazzo Massimo Lucarini Maria Alessandra Mobilia Besma Omri 《Natural product research》2020,34(1):110-121
AbstractTaxol is one of the anticancer drugs synthesized naturally in the evergreen Taxus brevifolia forest tree belonging to the yew family (Taxaceae) growing on the Pacific. There are reportedly evidence for treating ovarian, breast and lung cancers through this drug given its unique structural and functional features. Extraction of this drug from yew trees bark is one of the most common ways of producing this drug, but 3000 trees are needed to obtain a kilogram of Taxol. Hence, further attention has recently been attracted to the metabolic engineering strategies, including, engineering cellular metabolism of microorganisms and their optimization. Accordingly, the present paper article was aimed to review recent advances in elevating the production and commercialization of Taxol through metabolic engineering techniques. 相似文献
3.
Mansoori Arsalan Zahednezhad Fahimeh Bavili Tabrizi Ahad Shahbazi Mojarrad Javid 《Journal of the Iranian Chemical Society》2020,17(1):89-101
Journal of the Iranian Chemical Society - In the present study, we aimed to optimize the synthesis stages of S-pregabalin ((S)-3-(aminomethyl)-5-methylhexanoic acid), a well-known anticonvulsant... 相似文献
4.
Hossein Farsi Seyyed Amirhossein Hosseini 《Journal of Solid State Electrochemistry》2013,17(7):2079-2086
A simple coprecipitation method was used for preparation of monoclinic nanostructured NiWO4 from an aqueous solution at a fixed pH and temperature of 7.0 and 80 °C, respectively. The prepared material was characterized by X-ray diffraction, scanning electron microscopy, photoluminescence spectroscopy, and electrochemical measurements. Nano-NiWO4 was incorporated into a carbon paste electrode and by means of cyclic voltammetry; the electrochemical behavior of methylene blue on the surface of nano-NiWO4 was investigated. A mechanism on terms of obtained cyclic voltammograms showing one reduction peak and two sequential oxidation peaks was suggested by emphasizing on the stabilizing role of nano-NiWO4 for semi-methylene blue. A diffusion coefficient of 5.30?×?10?6 cm2/s was gained for methylene blue. 相似文献
5.
Amirhossein Saali Mohammad Shokouhi Hossein Sakhaeinia Nima Kazemi 《Journal of solution chemistry》2020,49(3):383-404
The thermodynamic consistency test of solubility P–T–x data for binary mixtures including carbon dioxide (CO2) + a room temperature ionic liquid has been investigated. Experimental solubility data taken from the open literature for 32 binary mixtures of CO2/RTILs contains 80 isotherms. The applied consistency test is based on the fundamental Gibbs–Duhem equation with use of the generic Redlich–Kwong (GRK) equation of state (EoS) coupled with the van der Waals–Berthelot (GRK/vdWB) mixing rule. The optimum parameters were obtained by minimizing the summation of per cent relative deviations between modeled and experimental data, based on the bubble pressure algorithm. Modeling was found acceptable for all isotherms, which demonstrated the usability of the GRK equation of state. Results of the thermodynamic consistency test showed that 36 of the isothermal data sets were thermodynamically consistent, 37 were not fully consistent, 6 were thermodynamically inconsistent and only one data set was found to need another model. 相似文献
6.
Vahid Beigi-Somar Seyed Saied Homami Majid Ghazanfarpour-Darjani Amirhossein Monzavi 《Journal of heterocyclic chemistry》2020,57(1):140-150
In situ generated copper acetylides react with isocyanates and oxiranes to form a decent range of morpholine derivatives. The reactions proceeded with acceptable yields and excellent regioselectivity. The presence of oxygen and moisture completely inhibited the reaction. The scope of the reaction is wide and the reactions involve consecutive C–C, C–N, and C–O bond formations. 相似文献
7.
Using the Martin-Siggia-Rose method, we study propagation of acoustic waves in strongly heterogeneous media which are characterized by a broad distribution of the elastic constants. Gaussian-white distributed elastic constants, as well as those with long-range correlations with nondecaying power-law correlation functions, are considered. The study is motivated in part by a recent discovery that the elastic moduli of rock at large length scales may be characterized by long-range power-law correlation functions. Depending on the disorder, the renormalization group (RG) flows exhibit a transition to localized regime in any dimension. We have numerically checked the RG results using the transfer-matrix method and direct numerical simulations for one- and two-dimensional systems, respectively. 相似文献
8.
Seyed Jalal Hosseinimehr Amirhossein Ahmadi Reza Taghvai 《Journal of Radioanalytical and Nuclear Chemistry》2010,284(3):563-566
Free radicals and oxidative stress are the primary causes of several chronic diseases such as cancer and heart disease. Quercetin
is a natural compound with potent antioxidant activity. We have prepared and evaluated technetium-99m (99mTc)-labeled quercetin as a potential radical scavenging radiotracer. A 99mTc-quercetin complex was prepared using quercetin, SnCl2 and Na99mTcO4 in a buffered solution over 30 min. The participation coefficient was measured in octanol and queues solutions. The stability
was determined in phosphate buffered saline and serum. The biodistribution in normal mice was evaluated at 0.5, 2, 6 and 24 h
post-injection. The radiochemical purity (>99%) was determined by thin layer chromatography (TLC) in normal saline solution
as the mobile phase. It has a log P of 0.204. It was mainly cleared by the kidneys and showed negligible brain uptake at four time points measured post-injection.
The pharmacological properties of quercetin, mainly its free radical scavenging, may potentially cat as a radiopharmaceutical
agent for radical-targeted imaging of tissue with high levels of reactive oxygen species. 相似文献
9.
Influence of thermal annealing on the structural and optical properties of maghemite (γ‐Fe2O3) nanoparticle thin films
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Ehsan Parsianpour Mohammad Gholami Nima Shahbazi Feridoun Samavat 《Surface and interface analysis : SIA》2015,47(5):612-617
In this study, maghemite (γ‐Fe2O3) nanoparticles were initially synthesized via chemical co‐precipitation and then deposited by spray pyrolysis as thin films on white glass substrates. The thin films were annealed for 8 h at 400, 450, 500, 550, and 600 °C in an oven. The structural studies of maghemite nanoparticles were carried out using X‐ray diffractometer. Structural properties that we investigated by X‐ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, SEM, and Energy dispersive X‐ray analysis (EDS). Optical properties of the samples were also investigated by ultraviolet‐visible (UV–vis) spectroscopy. The results showed that maghemite nanoparticles have crystalline structure with domain that increases in size with increasing annealing temperature. The optical band gap values were found to reduce from 2.9 to 2.4 eV with increase in annealing temperature. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
10.
Amirhossein Hajihosseini Farzaneh Maleki Gholam Reza Rokni Lamooki 《Chaos, solitons, and fractals》2011,44(11):1004-1019
A class of recurrent neural networks is constructed by generalizing a specific class of n-neuron networks. It is shown that the newly constructed network experiences generic pitchfork and Hopf codimension one bifurcations. It is also proved that the emergence of generic Bogdanov–Takens, pitchfork–Hopf and Hopf–Hopf codimension two, and the degenerate Bogdanov–Takens bifurcation points in the parameter space is possible due to the intersections of codimension one bifurcation curves. The occurrence of bifurcations of higher codimensions significantly increases the capability of the newly constructed recurrent neural network to learn broader families of periodic signals. 相似文献