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261.
In this paper, the problems of robust exponential generalized and robust exponential Q-S chaos synchronization are investigated between different dimensional chaotic systems. We consider the more practical and realistic cases when unknown time varying parameters with uncertainties, environmental disturbances, and nonlinearity of input control signals are present. The adaptive technique is employed to design the appropriate controllers and the validity of the proposed controllers are proved using Lyapunov stability theorem. Furthermore, numerical simulations are performed to show the efficiency of the presented scheme.  相似文献   
262.
263.
Résumé Le problème de Cauchy à une variable Fuchsienne a été traité par M. S.Baouendi et C.Goulaouic dans [1],dans [5]et [6],a été étudié le problème de Goursat à plusieurs variables Fuchsiennes, pour des opérateurs à partie dominante, d'abord dans le cas holomorphe puis le cas où les coefficientes sont réguliers par rapport aux variables Fuchsiennes. Ici nous allons chercher l'existence et l'unicité des solutions locales pour des opérateurs holomorphes sans partie dominante.  相似文献   
264.
本文讨论了用原子吸收和电感耦合等离子体发射光谱法(ICP-AES)测定经高压釜溶解的营养性埃及植物,如胡芦巴、甘草和莲座丛,并讨论了该法用于被消解植物样品中多元素日常分析的优点。这些样品具有较宽的元素含量范围,准确地测定这些营养性样品的主量和微量元素特别是有毒元素,对埃及人民的健康非常重要。ICP-AES法同时也用于被视为尼罗河净化剂的水生风信子的分析。分析结果表明,该植物能够有效地吸收有毒元素。被研究的植物经高压釜溶解,其溶液经原子吸收和ICP-AES法测定。作者对分析结果进行了对比,并阐明了二者之间的关系。  相似文献   
265.
New Plastic membrane ion-selective electrode for buspirone hydrochloride based on buspironium tetraphenylborate was prepared. The electrode exhibited mean slope of calibration graph of 58.4 mV per decade of BusCl concentration at 25 degrees C. The electrode can be used within the concentration range 6.3 x 10(-5) - 10(-2) M BusCl at a pH range of 2.5-7.0. The standard electrode potentials were determined at different temperatures and used to calculate the isothermal temperature coefficient of the electrode, amounting to 0.00056 V degrees C(-1). The electrode showed a very good selectivity for BusCl with respect to a number of inorganic cations, sugars and amino acids. The electrode was applied to the potentiometric determination of the buspirone ion and its pharmaceutical preparation under batch and flow injection conditions. Also, buspirone was determined by conductimetric titrations. Graphite rod, copper and silver coated wire electrodes were prepared and characterized as sensors for the drug under investigation.  相似文献   
266.
Thujone, which is the major constituent in Salvia sp. (Lamiaceae), was found to correct the lipid profile (cholesterol and triglycerides) in diabetic rats. Oral treatment with thujone (5 mg kg?1 body weight dose) significantly adjusted cholesterol and triglyceride levels in diabetic rats (p ≤ 0.05) to normal levels compared to diabetic untreated rats. This provides a premise in the field of finding new agents to treat diabetic complications.  相似文献   
267.
In the present study, structural properties of 2-[(1H-benzimidazol-2-ylmethyl)-amino]-benzoic acid methyl ester have been studied extensively by spectral methods and X-ray crystallography. Quantum mechanical calculations of energies, geometries, vibrational wavenumbers, NMR and electronic transitions were carried out by DFT using B3LYP functional combined with 6-31G(d) basis set. Natural bond orbitals (NBO) analysis and frontier molecular orbitals were performed at the same level of theory. DFT calculations showed good agreement between the theoretical and experimental values of optimized and X-ray structure as well as between the vibrational and NMR spectroscopy. The title compound was screened for its antibacterial activity referring to Tetracycline as standard antibacterial agent.  相似文献   
268.
Abstract

Cycloadditions of aldehydes with carbonyl ylides to give dioxolanes have been carried out without solvent under microwave irradiation. The reactions proceeded in similar yields and stereoselectivities, but in shorter reaction times, than those obtained in toluene at reflux using an oil bath. Cycloadditions conducted between imines and carbonyl ylides using the same protocol were less efficient because the oxazolidines formed proved unstable under the reaction conditions.  相似文献   
269.
The reaction of 3‐(dicyanomethylene)‐2‐indolone in a solution of ethanol/piperidine with 4‐substituted thiosemicarbazides forms the derivatives of 5′‐(substituted amino)‐3′H–spiro(indoline‐3,2′‐[1,3,4]thiadiazol‐2‐one. Rationales for these conversions involving the nucleophilic addition on the dicyanomethylene carbon atom are presented. The prepared compounds were evaluated each for antidepressant activity using tail suspension behavioral despair test and anticonvulsant activity against pentylenetetrazol induced seizures in mice. J. Heterocyclic Chem., (2011).  相似文献   
270.
We have previously reported a new synthesis of amides from esters and amines under microwave irradiation, offering much higher yields than those achieved with conventional heating [1]. We have now extended these studies to the ring closure of neat iminoesters I2, I3 and I4-I6 to give five- and six-membered ring lactams L5, L6 and larger lactams L7-L9 (where I means imine and L means lactam), respectively, under both classical heating conditions and microwave irradiation.  相似文献   
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