排序方式: 共有111条查询结果,搜索用时 31 毫秒
31.
Some sums of series of Rogers dilogarithm functions are established by Abel’s functional equation.
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32.
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
33.
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
34.
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
35.
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
36.
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
37.
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
38.
Esmaeili A Rustaiyan A Nadimi M Larijani K Nadjafi F Tabrizi L Chalabian F Amiri H 《Natural product research》2008,22(6):516-520
The essential oils obtained by hydrodistillation of the leaves, stems and flowers of Salvia reuterana (Lamiaceae) were analysed by GC and GC/MS. Germacrene D and beta-caryophyllene were the major constituents in all the three oils: (28.5, 27.7 and 32.5%) and (15.5, 11.4 and 16.6%), respectively. Bicyclogermacrene (10.2 and 13.2%) was also prodominated in the stem and flower oils. The composition of the oils was mostly quantitativel rather than qualitatively different. All the oils consisted mainly of sesquiterpenes and a small percentage of non-terpenoid compounds. In all the three oils, monoterpenes were in a concentration less than 0.5%. Antibacterial activity was determined by the measurement of growth inhibitory zones. 相似文献
39.
Naseri NG Baldock SJ Economou A Goddard NJ Fielden PR 《Analytical and bioanalytical chemistry》2008,391(4):1283-1292
Catalytic adsorptive stripping voltammetry (CAdSV) has been demonstrated at a bismuth film electrode (BiFE) in an injection-moulded
electrochemical micro-flow cell. The polystyrene three-electrode flow cell was fabricated with electrodes moulded from a conducting
grade of polystyrene containing 40% carbon fibre, one of which was precoated with Ag to enable its use as an on-chip Ag/AgCl
reference electrode. CAdSV of Co(II) and Ni(II) in the presence of dimethylglyoxime (DMG) with nitrite employed as the catalyst
was performed in order to assess the performance of the flow cell with an in-line plated BiFE. The injection-moulded electrodes
were found to be suitable substrates for the formation of BiFEs. Key parameters such as the plating solution matrix, plating
flow rate, analysis flow rate, solution composition and square-wave parameters have been characterised and optimal conditions
selected for successful and rapid analysis of Co(II) and Ni(II) at the ppb level. The analytical response was linear over
the range 1 to 20 ppb and deoxygenation of the sample solution was not required. The successful coupling of a microfluidic
flow cell with a BiFE, thereby forming a “mercury-free” AdSV flow analysis sensor, shows promise for industrial and in-the-field
applications where inexpensive, compact, and robust instrumentation capable of low-volume analysis is required. 相似文献
40.
Moheb Amir Mahani Ahmad Naseri Karimvand Naser Naserifar 《Journal of separation science》2023,46(19):2300257
Point-of-care diagnostics requires a smart separation of particles and/or cells. In this work, the multiorifice fluid fractionation as a passive method and dielectrophoresis-based actuator as an active tool are combined to offer a new device for size-based particle separation. The main objective of the combination of these two well-established techniques is to improve the performance of the multiorifice fluid fractionation by taking advantage of dielectrophoresis-based actuator for separating particles. Initially, by using numerical simulations, the effect of using dielectrophoresis-based actuator in multiorifice fluid fractionation on the separation of particles was investigated, and the size of the device was optimized by 25% compared to a device without dielectrophoresis-based actuator. Also, adding dielectrophoresis-based actuator to multiorifice fluid fractionation can extend the range of flow rates needed for separation. In the absence of dielectrophoresis-based actuator, the separation took place only when the flow rate is 100 μL/min, in the presence of dielectrophoresis-based actuator (20 Vp-p), the separation happened in flow rates ranging from 70 to 120 μL/min. 相似文献