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排序方式: 共有183条查询结果,搜索用时 15 毫秒
81.
Polyesters consisting of substituted aromatic type Schiff base mesogenic unit andpolymethylene spacers were synthesized and their thermal transitions and liquid crystallineproperties were studied. The liquid crystalline behaviour has been characterized by differentialscanning calorimetry (DSC) and optical polarizing microscopy. Structural broadening bysubstitution of methoxy group in 2, 2" positions of the mesogenic core produce polymers withlower transition temperatures. Polymers synthesized from ortho and meta substituted phenylenediamine did not form a liquid crystal phase. 相似文献
82.
Godard C López-Serrano J Gálvez-López MD Roselló-Merino M Duckett SB Khazal I Lledós A Whitwood AC 《Magnetic resonance in chemistry : MRC》2008,46(Z1):S107-S114
In-situ NMR studies on the reactions of Pt{CH2 = CHSi(Me)2}2O)(PCy3) with phosphines, HSiEt3 and--hydrogen or Pt(L)(L')(Me)(2) alone enable the detection of cis-Pt(L)(L')(H)2 [L = PCy3 and L' = PCy2H, PPh3 or PCy3] which then undergo hydride site interchange and H2 reductive elimination on the NMR timescale. 相似文献
83.
Li Yicheng Moradi Iman Kalantar Mahdi Babadi Elmira Malekahmadi Omid Mosavi Amirhosein 《Journal of Thermal Analysis and Calorimetry》2021,144(6):2587-2603
Journal of Thermal Analysis and Calorimetry - Nanofluid refers to the mixture of fluid and solid nanoparticles. If this mixture contains more than one NP or fluid, it is called “hybrid... 相似文献
84.
Structural Chemistry - The detection methods used to analyze abused drugs should be sensitive sufficiently. Here in, we propose carbon nanotube (CNT) functionalized with COOH and CONHCH3 groups as... 相似文献
85.
Nouria Boussalah Rachid Touzani Faiza Souna Iman Himri Mohammed Bouakka Abdelkader Hakkou Said Ghalem Sghir El Kadiri 《Journal of Saudi Chemical Society》2013,17(1):17-21
Series of functional multidendate ligands based on pyrazole and amino acid derivatives were prepared in good and excellent yields (75–5%) by condensation of one equivalent of amino acid ester hydrochloride substrates with two equivalents of (3,5-dimethyl-1H–pyrazol-1-yl)methanol. These tridentate functionalized compounds and their starting materials were screened for their antifungal activities against Fusarium oxysporum f.sp. albedinis and the yeast of Saccharomyces cerevisiae. Considerable activities were recorded with respect to the two studied microorganisms. 相似文献
86.
Alireza Feizbakhsh Ali Aghassi Ali Ehsani Malihe A. Jamaat Ali Naeemy Iman Danaee 《中国化学会会志》2012,59(9):1086-1093
In this study we investigated the electrocatalytic oxidation of anti‐inflammatory drug (paracetamol) on Nickel and Nickel–copper alloy modified glassy carbon electrodes (GC/Ni and GC/NiCu) in alkaline solution. These electrodes prepared by galvanostatic method and different electrochemical techniques such as cyclic voltammetry and chronoamperometry were used to track the oxidation process and its kinetics. From Voltammetric studies we concluded that in the presence of drugs the anodic peak current of low valences Nickel species increased, followed by a decrease in the corresponding cathodic current peak. This indicates that drugs were oxidized on the redox mediator which was immobilized on the electrode surface via an electrocatalytic mechanism. Using Laviron's equation, the values of α and ks for the immobilized redox species were determined. The anodic peak currents show linear dependency with the square root of scan rate. This behavior is the characteristic of a diffusion controlled process. Under the CA regime the reaction followed a Cottrellian behavior and the diffusion coefficient of paracetamol was found in agreement with the values obtained from CV measurements. 相似文献
87.
Iman?Jabbari Zahir Abadi Omid?Sadeghi Hamid?Reza?Lotfizadeh Zhad Najmeh?Tavassoli Vahid?Amani Mostafa?M.?AminiEmail author 《Journal of Sol-Gel Science and Technology》2012,61(1):90-95
Nanoporous silica SBA-15 was prepared to evaluate its application as an oral drug delivery system. A series of surface-functionalized
nanopore materials as efficient clarithromycin delivery carriers was investigated. An efficient pH-responsive carrier system
was constructed by hydrogen bond interaction between carboxyl and hydroxyl groups in the clarithromycin and the amine group
in modified SBA-15. HPLC analyses of clarithromycin were run on a C18 column using a mobile phase comprised of potassium dihydrogen phosphate, acetonitrile and methanol (30:40:30, v/v/v). Active
molecules such as clarithromycin could be stored and released from the pore voids of SBA-15 by changing the pH. The amount
of clarithromycin stored in the pores of nanoporous silica based on TREN [tris(2-aminoethyl) amine]-modified SBA-15 rods was
up to 46 ± 4.8 wt% at pH 8. In addition, when the pH was below 4, clarithromycin was steadily released from the pores of SBA-15
(up to 97 wt% in simulated gastric medium). 相似文献
88.
Kyu Ok Jeon Dinesh Rayabarapu Alan Rolfe Kelly Volp Iman Omar Paul R. Hanson 《Tetrahedron》2009,65(26):4992-7773
The development of a ring-opening metathesis/ring-closing metathesis/cross-metathesis (ROM-RCM-CM) cascade strategy to the synthesis of a diverse collection of bi- and tricyclic sultams is reported. In this study, functionalized sultam scaffolds derived from intramolecular Diels-Alder (IMDA) reactions undergo metathesis cascades to yield a collection of tricyclic sultams. Additional appendage-based diversity was achieved by utilizing a variety of CM partners. 相似文献
89.
Dynamical behavior of particles in a Paul trap in the presence of damping force has been investigated. Position of trapped ions as a function of time, ion trajectories and the phase space curves considering the effect of the damping force were obtained. Four regions of stability for r and z components with the damping force as well as the maximum value of q when U = 0 for the first region, namely qmax, versus damping factor k were computed using the fourth-order Runge–Kutta method. Comparisons were made with the corresponding stability diagrams without the damping force effect recently published in the literature. The third and fourth stability regions in the presence of the damping force, the curve of qmax as a function of k and the related equation are reported for the first time. 相似文献
90.
Chaichi MJ Azizi SN Heidarpour M Aalijanpour O Qandalee M 《Journal of fluorescence》2012,22(5):1209-1216
Furan derivatives (synthesized and purified in organic laboratories) are a great interest as fluorescent emitters for peroxyoxalate chemiluminescence. Reaction of peroxyoxalates such as bis-(2,4,6-trichloro-phenyl) oxalate with H(2)O(2) can transfer energy to fluorophore via formation of dioxetanedione intermediate. Furan derivatives used as a novel fluorescer in this study which produces a blue light in the chemiluminescence systems. The relationship between the chemiluminescence intensity and concentrations of TCPO, sodium salicylate, hydrogen peroxide and the fluorescer has been investigated. The linear ranges for Furan derivatives were 0.25-5?×?10(-4)?M and 0.1-5?×?10(-4)?M (A and B compounds, respectively). Kinetic parameters for the peroxyoxalate-chemiluminescence were also calculated from the computer fitting of the corresponding chemiluminescence intensity/time profiles. 相似文献