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301.
William Clegg Ross W. Harrington Kazem Barati Mohammad Hossein Habibi Morteza Montazerozohori Arash Lalegani 《Acta Crystallographica. Section C, Structural Chemistry》2015,71(7):578-583
Reaction of copper(I) thiocyanate and triphenylphosphane with the bidentate Schiff base N,N′‐bis(trans‐2‐nitrocinnamaldehyde)ethylenediamine {Nca2en, (1); systematic name (1E,1′E,2E,2′E)‐N,N′‐(ethane‐1,2‐diyl)bis[3‐(2‐nitrophenyl)prop‐2‐en‐1‐imine]}, C20H18N4O4, in a 1:1:1 molar ratio in acetonitrile resulted in the formation of the complex {(1E,1′E,2E,2′E)‐N,N′‐(ethane‐1,2‐diyl)bis[3‐(2‐nitrophenyl)prop‐2‐en‐1‐imine]‐κ2N,N′}(thiocyanato‐κN)(triphenylphosphane‐κP)copper(I)], [Cu(NCS)(C20H18N4O4)(C18H15P)] or [Cu(NCS)(Nca2en)(PPh3)], (2). The Schiff base and copper(I) complex have been characterized by elemental analyses, IR, electronic and 1H NMR spectroscopy, and X‐ray crystallography [from synchrotron data for (1)]. The molecule of (1) lies on a crystallographic inversion centre, with a trans conformation for the ethylenediamine unit, and displays significant twists from coplanarity of its nitro group, aromatic ring, conjugated chain and especially ethylenediamine segments. It acts as a bidentate ligand coordinating via the imine N atoms to the CuI atom in complex (2), in which the ethylenediamine unit necessarily adopts a somewhat flattened gauche conformation, resulting in a rather bowed shape overall for the ligand. The NCS− ligand is coordinated through its N atom. The geometry around the CuI atom is distorted tetrahedral, with a small N—Cu—N bite angle of 81.56 (12)° and an enlarged opposite angle of 117.29 (9)° for SCN—Cu—P. Comparisons are made with the analogous Schiff base having no nitro substituents and with metal complexes of both ligands. 相似文献
302.
The lateral Casimir force is employed to propose a design for a potentially wear-proof rack and pinion with no contact, which can be miniaturized to the nanoscale. The robustness of the design is studied by exploring the relation between the pinion velocity and the rack velocity in the different domains of the parameter space. The effects of friction and added external load are also examined. It is shown that the device can hold up extremely high velocities, unlike what the general perception of the Casimir force as a weak interaction might suggest. 相似文献
303.
Arash Sioofy Khoojine Mahdi Shadabfar Vahid Reza Hosseini Hadi Kordestani 《Entropy (Basel, Switzerland)》2021,23(10)
Predicting the way diseases spread in different societies has been thus far documented as one of the most important tools for control strategies and policy-making during a pandemic. This study is to propose a network autoregressive (NAR) model to forecast the number of total currently infected cases with coronavirus disease 2019 (COVID-19) in Iran until the end of December 2021 in view of the disease interactions within the neighboring countries in the region. For this purpose, the COVID-19 data were initially collected for seven regional nations, including Iran, Turkey, Iraq, Azerbaijan, Armenia, Afghanistan, and Pakistan. Thenceforth, a network was established over these countries, and the correlation of the disease data was calculated. Upon introducing the main structure of the NAR model, a mathematical platform was subsequently provided to further incorporate the correlation matrix into the prediction process. In addition, the maximum likelihood estimation (MLE) was utilized to determine the model parameters and optimize the forecasting accuracy. Thereafter, the number of infected cases up to December 2021 in Iran was predicted by importing the correlation matrix into the NAR model formed to observe the impact of the disease interactions in the neighboring countries. In addition, the autoregressive integrated moving average (ARIMA) was used as a benchmark to compare and validate the NAR model outcomes. The results reveal that COVID-19 data in Iran have passed the fifth peak and continue on a downward trend to bring the number of total currently infected cases below 480,000 by the end of 2021. Additionally, 20%, 50%, 80% and 95% quantiles are provided along with the point estimation to model the uncertainty in the forecast. 相似文献
304.
High-order discretizations of partial differential equations(PDEs)necessitate high-order time integration schemes capable of handling both stiff and nonstiff op... 相似文献
305.
Notes on Groundwater Age in Forward and Inverse Modeling 总被引:2,自引:0,他引:2
Timothy R. Ginn Hanieh Haeri Arash Massoudieh Laura Foglia 《Transport in Porous Media》2009,79(1):117-134
Several example applications of the groundwater age equation are used to derive some basic results about age in aquifers and
to draw linkages among published results involving temporal moments and aquifer–aquitard diffusive mass transfer. We then
describe a brief numerical study of an inverse problem in which hydraulic conductivities are identified using both piezometric
head and groundwater age data where inclusion of age data helps to reduce evidential nonuniqueness. This reflects the global
representation of flow process contained in age data, and that the value of age data in inverse identification of flow properties
depends on the paths taken by the sampled groundwater.
Paper presented at PORO2007, the 7th North American Workshop on Applications of the Physics of Porous Media, Puerto Vallarta,
Mexico, 2–6 November, 2007. 相似文献
306.
Moradi Iman Karimipour Arash Afrand Masoud Li Z. Bach Quang-Vu 《Journal of Thermal Analysis and Calorimetry》2020,141(5):1647-1667
Journal of Thermal Analysis and Calorimetry - Notwithstanding the widespread use of wind tunnel to investigate the performance of radiators and heat exchangers, has never been considered a... 相似文献
307.
Peng Yeping Zahedidastjerdi Ali Abdollahi Ali Amindoust Atefeh Bahrami Mehrdad Karimipour Arash Goodarzi Marjan 《Journal of Thermal Analysis and Calorimetry》2020,139(4):2623-2631
Journal of Thermal Analysis and Calorimetry - This work is a three-dimensional numerical study of a U-shaped evacuated tube solar collector employing different types of oxide nanofluids including... 相似文献
308.
Reza Hoseinpour Kouhestany Atefeh Tamaddon Homayoon Ahmad Panahi Arash Afshar Ebrahimi Rahebeh Amiri 《Biomedical chromatography : BMC》2022,36(3):e5284
Polyaniline nanofiber films were fabricated on the surface of stainless steel wire via a controllable and simple electrophoretic deposition route from a nonaqueous colloidal suspension consisting of polyaniline nanofibers. The prepared coating material was then characterized by field emission scanning electron microscopy equipped with energy dispersive spectroscopy and elemental mapping analysis. The fabricated polyaniline film-coated stainless steel wire was then utilized as an effective and novel sorbent phase for solid-phase microextraction of tamoxifen for subsequent gas chromatography/flame ionization detection of this anticancer drug. Parameters consisting of the temperature, extraction time, salt concentration, agitation speed, pH, temperature and time of desorption were studied and optimized using a one-at-a-time strategy. Under the optimum conditions, detection limit (S/N = 3), the limit of quantification (10/3 limit of detection), linear dynamic range, repeatability and reproducibility values of 0.51 μg L−1, 1.7 μg L−1, 2–1,130 μg L−1, 5.7% and 8.6% were attained, respectively. The prepared fiber can preserve 90% of its efficacy after 20 consecutive cycles, demonstrating the suitable thermal stability and cyclability of the proposed solid-phase microextraction coating material for the determination of tamoxifen by gas chromatography/flame ionization detection. The route was effectively utilized to determine tamoxifen in urine samples, with relative recoveries ranging from 89 to 106%. 相似文献
309.
High‐speed compressible turbulent flows typically contain discontinuities and have been widely modeled using Weighted Essentially Non‐Oscillatory (WENO) schemes due to their high‐order accuracy and sharp shock capturing capability. However, such schemes may damp the small scales of turbulence and result in inaccurate solutions in the context of turbulence‐resolving simulations. In this connection, the recently developed Targeted Essentially Non‐Oscillatory (TENO) schemes, including adaptive variants, may offer significant improvements. The present study aims to quantify the potential of these new schemes for a fully turbulent supersonic flow. Specifically, DNS of a compressible turbulent channel flow with M = 1.5 and Reτ = 222 is conducted using OpenSBLI, a high‐order finite difference computational fluid dynamics framework. This flow configuration is chosen to decouple the effect of flow discontinuities and turbulence and focus on the capability of the aforementioned high‐order schemes to resolve turbulent structures. The effect of the spatial resolution in different directions and coarse grid implicit LES are also evaluated against the WALE LES model. The TENO schemes are found to exhibit significant performance improvements over the WENO schemes in terms of the accuracy of the statistics and the resolution of the three‐dimensional vortical structures. The sixth‐order adaptive TENO scheme is found to produce comparable results to those obtained with nondissipative fourth‐ and sixth‐order central schemes and reference data obtained with spectral methods. Although the most computationally expensive scheme, it is shown that this adaptive scheme can produce satisfactory results if used as an implicit LES model. 相似文献
310.
Summary: This study has tried to use HDPE and the coupling agent consistent MAPP and cornstalk fibers, create wood plastic composite material and its physical and mechanical properties such as tensile modulus, flexural modulus and humidity absorption is measured. After determining the percentage of 20, 30 and 40% of corn stalk fibers in the product and the use of two longitudinal mesh levels of 40 and 80 of them and using the 5% MAPP coupling agent testing was done and it was shown that increasing fiber length and percent increase in product humidity is absorbed. This is while the declines by increasing the fiber length changes of samples were during the tensile tests. In the bending test also increased fiber length and flexural modulus was increased. 相似文献