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991.
Maryam Shojaei Abdolreza Mirmohseni Yadollah Omidi Maryam Farbodi 《Applied biochemistry and biotechnology》2009,159(1):54-64
Homovanillic acid (HVA) and vanillylmandelic acid (VMA) were selectively determined by quartz crystal nanobalance sensor in
conjunction with net analyte signal (NAS)-based method called HLA/GO. An orthogonal design was applied for the formation of
calibration and prediction sets including HVA, VMA, and some common and structurally similar urine compounds. The selection
of the optimal time range involved the calculation of the NAS regression plot in any considered time window for each test
sample. The searching of a region with maximum linearity of NAS regression plot (minimum error indicator) and minimum of predicted
error sum of squares value was carried out by applying a moving window strategy. Based on the obtained results, the differences
on the adsorption profiles in the time range between 1 and 300 s were used to determine mixtures of compounds by HLA/GO method.
Several figures of merit like selectivity, sensitivity, analytical sensitivity, and limit of detection were calculated for
both compounds. The results showed that the method was successfully applied for the determination of VMA and HVA. 相似文献
992.
Maryam Bordbar Ali Yeganeh-Faal Jahanbakhsh Ghasemi Mohammad Mahdi Ahari-Mostafavi Nahid Sarlak Mohammad Taghi Baharifard 《Chemical Papers》2009,63(3):336-344
A simple, sensitive and selective spectrophotometric method for simultaneous determination of tretinoin and minoxidil using
partial least square (PLS) calibration and H-point standard addition method (HPSAM) is described. The results of the H-point
standard addition method show that minoxidil and tretinoin can be determined simultaneously with the concentration ratio of
tretinoin to minoxidil varying from 2: 1 to 1: 33 in mixed samples. A partial least squares multivariate calibration method
for the analysis of binary mixtures of tretinoin and minoxidil was also developed. The total relative standard error for applying
the PLS method to eleven synthetic samples in the concentration range of 0–10 μg mL−1 tretinoin and 0–32 μg mL−1 minoxidil was 2.59 %. Both proposed methods (PLS and HPSAM) were also successfully applied in the determination of tretinoin
and minoxidil in several synthetic pharmaceutical solutions. 相似文献
993.
1‐Butyl‐3‐methylimidazolium hydrogen sulfate [bmim]HSO4 as an acidic ionic liquid was prepared and used as a catalyst for the synthesis of 1,8‐dioxo‐octahydroxanthenes in excellent yields and short reaction times at 80 °C. The ionic liquid was easily separated from the reaction mixture by water extraction and was recycled four times without any loss in activity. 相似文献
994.
Summary The reaction between alkyl(aryl) isocyanides and dibenzoylacetylene in the presence of ethyl bromopyruvate leads to ethyl 3,4-dibenzoyl-2-bromomethyl-5-alkyl(aryl)imino-2,5-dihydro-furan-2-carboxylates in high yields. Dialkyl acetylenedicarboxylates react with tert-butyl isocyanide and ethyl bromopyruvate to produce 3,4-dialkyl 2-ethyl 2-bromomethyl-5-tert-butylimino-2,5-dihydro-furan-2,3,4-tricarboxylates. 相似文献
995.
Treatment of triphenylphosphine with dialkyl acetylenedicarboxylate leads to 1:1 adduct and concomitant protonation of late adduct by pentan‐2,3,4‐trione 3‐oxime gave the reactive intermediate, vinyltriphenylphosphonium salts, which undergoes an intramolecular Wittig reaction to produce tetrasubstituted N‐hydroxypyrroles in fairly high yields. © 2008 Wiley Periodicals, Inc. Heteroatom Chem 19:100–103, 2008; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20382 相似文献
996.
Issa Yavari Zinatossadat Hossaini Maryam Sabbaghan Majid Ghazanfarpour-Darjani 《Molecular diversity》2009,13(3):295-300
An efficient one-pot synthesis of ethyl 2-(4-aryl-2-dialkylamino-1,3-thiazole-5-yl)-2-oxoacetates using acid chlorides, secondary
amines, ethyl bromopyruvate, and ammonium thiocyanate is described. 相似文献
997.
Elahe Mirzaie-Khalilabadi Maryam Dehestani 《International journal of quantum chemistry》2019,119(19):e25993
In this work, we examine nonadiabatic population dynamics for 11B1 and 11A2 states of ozone molecule (O3). In O3, two lowest singlet excited states, 1A2 and 1B1, can be coupled. Thus, population transfer between them occurs through the seam involving these two states. At any point of the seam (conical intersection), the Born-Oppenheimer approximation breaks down, and it is necessary to investigate nonadiabatic dynamics. We consider a linear vibronic coupling Hamiltonian model and evaluate vibronic coupling constant, diabatic frequencies for three modes of O3, bilinear and quadratic coupling constants for diabatic potentials, displacements, and Huang-Rhys coupling constants using ab initio calculations. The electronic structure calculations have been performed at the multireference configuration interaction and complete active space with second-order perturbation theory with a full-valence complete active space self-consistent field methods and augmented Dunning's standard correlation-consistent-polarized quadruple zeta basis set to determine ab initio potential energy surfaces for the ground state and first two excited states of O3, respectively. We have chosen active space comprising 18 electrons distributed over 12 active orbitals. Our calculations predict the linear vibronic coupling constant 0.123 eV. We have obtained the population on the 11B1 and 11A2 excited electronic states for the first 500 fs after photoexcitation. 相似文献
998.
We modeled a one-dimensional actuator including the Casimir and electrostatic forces perturbed by an external force with fractional damping. The movable electrode was assumed to oscillate by an anharmonic elastic force originated from Murrell–Mottram or Lippincott potential. The nonlinear equations have been solved via the Adomian decomposition method. The behavior of the displacement of the electrode from equilibrium position, its velocity and acceleration were described versus time. Also, the changes of the displacement have been investigated according to the frequency of the external force and the voltage of the electrostatic force. The convergence of the Adomian method and the effect of the orders of expansion on the displacement versus time, frequency, and voltage were discussed. The pull-in parameter was obtained and compared with the other models in the literature. This parameter was described versus the equilibrium position and anharmonicity constant. 相似文献
999.
Ferdows B. Zarrabi Reza Hekmati Maryam Bazgir Sepideh Ebrahimi 《Optical and Quantum Electronics》2018,50(12):452
In optical devices, the polarization of the incident wave affects the Nano particle characteristics. Therefore, designing a polarization-independent device is significant in the process of designing optical structures. On the other hand, the concept of Fano resonance and dark mode has been utilized for achieving more energy enhancement. In this paper, we have developed a symmetrical Nano antenna by employing Fano resonance, which is independent of the incident wave polarization. The proposed Nano antenna is modified in mid infrared regime for biosensing and energy harvesting applications. The designed metamaterial antenna is made by Nano split ring resonators with etched capacitive gaps, which are utilized for concentrating energy. The introduced Nano antenna has a bright and dark mode with a weak enhancement of electric field. The effect of the incident wave polarization is investigated at wave incident angles between 0° and 45° to illustrate the independency of the polarization due to the symmetrical shape of the Nano antenna. In order to trigger the dark mode and enhance the electric field, a Nano chain is incorporated in the final structure. This arrangement has led to increasing of electric field drastically. Furthermore, the figure of merit has been calculated as an advantageous factor in sensing the surrounding materials with various refractive indices. Our findings illustrated that the chain arrangement has caused a peak in the linear form of the extinction cross section of the Nano antenna. This in turn has resulted in the appearance of Fano resonance with no impact on the resonance frequency that has been originally adjusted by capacitive gaps and inductive strips. 相似文献
1000.
We prove some ergodic-theoretic rigidity properties of the action of Open image in new window on moduli space. In particular, we show that any ergodic measure invariant under the action of the upper triangular subgroup of Open image in new window is supported on an invariant affine submanifold.The main theorems are inspired by the results of several authors on unipotent flows on homogeneous spaces, and in particular by Ratner’s seminal work. 相似文献