排序方式: 共有90条查询结果,搜索用时 312 毫秒
21.
Mosayeb Naseri Shiru Lin Jaafar Jalilian Jinxing Gu Zhongfang Chen 《Frontiers of Physics》2018,13(3):138102
By means of density functional theory computations, we predicted two novel two-dimensional (2D) nanomaterials, namely P2X (X=C, Si) monolayers with pentagonal configurations. Their structures, stabilities, intrinsic electronic, and optical properties as well as the effect of external strain to the electronic properties have been systematically examined. Our computations showed that these P2C and P2Si monolayers have rather high thermodynamic, kinetic, and thermal stabilities, and are indirect semiconductors with wide bandgaps (2.76 eV and 2.69 eV, respectively) which can be tuned by an external strain. These monolayers exhibit high absorptions in the UV region, but behave as almost transparent layers for visible light in the electromagnetic spectrum. Their high stabilities and exceptional electronic and optical properties suggest them as promising candidates for future applications in UV-light shielding and antireflection layers in solar cells. 相似文献
22.
Hamid Saeidian Mehran Babri Davood Ashrafi Mansour Sarabadani Mohammad Taghi Naseri 《Analytical and bioanalytical chemistry》2013,405(21):6749-6759
The electron-impact (EI) mass spectra of a series of O-alkyl methylphosphonothionocyanidates were studied for Chemical Weapons Convention (CWC) purposes. General EI fragmentation pathways were constructed and discussed, and collision-induced dissociation studies of the major EI ions were performed to confirm proposed fragment structures by analyzing fragment ions of deuterated analogs and by use of density functional theory (DFT) calculations. Thiono–thiolo rearrangement, McLafferty-type rearrangement, and a previously unknown intramolecular electrophilic aromatic substitution reaction were observed and confirmed. The study also focused on differentiation of isomeric compounds. Retention indices for all compounds, and an electrophilicity index for several compounds, are reported and interpreted. 相似文献
23.
Akhundi Anise Naseri Amene Abdollahi Nasrin Samadi Morasae Moshfegh Alireza 《Research on Chemical Intermediates》2022,48(5):1793-1811
Research on Chemical Intermediates - Worldwide energy and environmental issues are forcing researchers to develop a green approach to produce a clean energy. However, traditional methods in... 相似文献
24.
25.
Oscillating chemical reactions are complex systems, involving a large number of chemical species. In oscillating chemical reaction, some species, usually a reaction intermediate, exhibit fluctuation in its concentration. In this report, visible oscillating chemiluminescence produced by the addition of luminol (3-aminophthalhydrazide) to the oscillating system of H2O2=KSCN=CuSO4=TMAOH was investigated using spectrofluorimetry method. The effects of ingredient concentration of the oscillating system and complexing agents like citric acid and cysteine on the behavior of the oscillating system were investigated. Moreover, the influence of nonaqueous solvents such as ethanol and ethylene glycol has been studied. 相似文献
26.
In this paper, a novel numerical method is proposed to solve specific third order ODE on semi-infinite interval. These kinds of problems often occur in laminar boundary layer with temperature dependent viscosity. Runge-Kutta method incorporating with optimization techniques is used to solve the problem. First, the semi-infinite interval is transformed into a finite interval. Second, by converting the boundary value problem, with some initial and distributed unknowns, into an optimization problem, solving the original problem is limited to solving a multiobjective optimization problem. Third, we use shooting-Newton’s method for solving this optimization problem. It is shown that the Falkner-Skan problem with constant surface temperature, that arise during the solution for the laminar forced convection heat transfer from wedges to flow, can be solved accurately and simultaneously by this strategy. Numerical results for different values of wedge angle and Prandtl number are presented, which are in good agreement with some of the successful provided solutions in the literature. 相似文献
27.
M. Goodarz Naseri E. Bin SaionH. Abbastabar Ahangar M. Hashim A.H. Shaari 《Journal of magnetism and magnetic materials》2011,323(13):1745-1749
Cubic structured manganese ferrite nanoparticles were synthesized by a thermal treatment method followed by calcination at various temperatures from 723 to 873 K. In this investigation, we used polyvinyl pyrrolidon (PVP) as a capping agent to control the agglomeration of the nanoparticles. The characterization studies were conducted by X-ray diffraction (XRD) and transmission electron microscopy (TEM). The average particle sizes of manganese ferrite nanoparticles were determined by TEM, which increased with the calcination temperature from 12 to 22 nm and they had good agreement with XRD results. Fourier transform infrared spectroscopy confirmed the presence of metal oxide bands at all temperatures and the absence of organic bands at 873 K. Magnetic properties were demonstrated by a vibrating sample magnetometer, which showed a super-paramagnetic behavior for all samples and also saturation magnetization (Ms) increases from 3.06 to 15.78 emu/g by increasing the calcination temperature. The magnetic properties were also confirmed by the use of electron paramagnetic resonance spectroscopy, which revealed the existence of unpaired electrons and also measured peak-to-peak line width, resonant magnetic field and the g-factor. 相似文献
28.
A. R. Khataee M. Fathinia A. Naseri A. Hasanzadeh F. Vafaei A. Emami Y. Hanifehpour S. W. Joo 《Research on Chemical Intermediates》2014,40(3):1283-1302
In this paper, ceramic plates were used as a support of TiO2 nanoparticles for photocatalytic decolorization of a mixture of three dyes. The three textile dyes (C.I. Basic Red 46, C.I. Basic Blue 3 and Malachite Green) were quantified simultaneously during the photocatalytic degradation process. The partial least squares modeling was successfully applied for the multivariate calibration of the spectrophotometric data. Also, the central composite design has been applied to the optimization of photocatalytic decolorization of the dye solution containing three dyes using an immobilized UV/TiO2 process. The optimum initial concentration of three dyes, reaction time, and UV light intensity were found to be 5 mg/L, 240 min, and 47.2 W/m2, respectively. The chronic phytotoxicity of mixture of dyes was evaluated using aquatic species Spirodela polyrhiza (S. polyrhiza) prior to and after photocatalysis. The phytotoxicity results revealed that the photocatalysis process could effectively reduce the phytotoxicity of the dyes from their aqueous solutions. 相似文献
29.
García F Less RJ Naseri V McPartlin M Rawson JM Sancho Tomas M Wright DS 《Chemical communications (Cambridge, England)》2008,(7):859-861
The two products obtained from the reaction of 1,2-(PH(2))(2)C(6)H(4) with the mixed-metal base (n)BuLi-Sb(NMe(2))(3) in the presence of 12-crown-4, [Li(12-crown-4)(2)]+[C(6)H(4)P(3)]- (1) and {[Li(12-crown-4)(2)]+}3[Sb(11)]3- (2), represent thermodynamic sinks in which P-P and Sb-Sb bonding are maximized at the expense of P-Sb bonding, providing access to the 1,2,3-[C(6)H(4)P(3)]- phospholide anion. 相似文献
30.
García F Less RJ Naseri V McPartlin M Rawson JM Wright DS 《Dalton transactions (Cambridge, England : 2003)》2008,(8):997-999
The reaction of 1,2-(NH(2))(2)C(6)H(4) with Sb(NMe(2))(3)/(n)BuLi gives the formally-aromatic heterocyclic anion [C(6)H(4)N(2)Sb](-) which oligomerises into a cyclic tetrameric arrangement in the complex [C(6)H(4)N(2)SbLi.PMDETA](4) () (PMDETA = {Me(2)NCH(2)CH(2)}(2)NMe) using a donor-acceptor bonding mode that is unique in related main group heterocyclic anions. 相似文献