排序方式: 共有15条查询结果,搜索用时 625 毫秒
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M. Mazloum Ardakani Z. Akrami H. Kazemian Hamid R. Zare 《Journal of Analytical Chemistry》2008,63(2):184-191
Chemically modified electrodes based on zeolite-containing graphite pastes were constructed and evaluated as sensor electrodes for the voltammetric determination of trace cobalt in solution. Zeolite molecular sieves with pore sizes of 3, 4, and 5 Å were all suitable for chemical deposition and subsequent voltammetric quantitation of trace Co(II). In order to cover a large range of parameters, the investigations were carried out using three zeolites (A, X, and Y), selected for their different cation-exchange capacities and ion-sieving properties. The analytical scheme, “preconcentration/voltammetric detection” for the determination of cobalt(II) species using zeolite-modified carbon paste electrodes (ZMCPE) was chosen. Compared to the corresponding unmodified electrodes, improvements in sensitivity were observed when using ZMCPEs due to analyte accumulation at the electrode’s surface by ion exchange in zeolite particles. The detection limit obtained for Co(II) was 3 ppm following 15 min of chemical deposition. A good correlation was found between the results obtained by ion exchange voltammetry and conventional ion-exchange characterization. 相似文献
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Ehsan Bahmani Babak Faraji Dizaji Sam Talaei Shahnaz Koushkbaghi Hamid Yazdani Parvaneh Ghaderi-shekhi Abadi Mohammad Akrami Mohsen Shahrousvand Fariborz Sharifian Jazi Mohammad Irani 《先进技术聚合物》2023,34(2):789-799
In the present study, paclitaxel (PTX), multi-walled carbon nanotubes (MWCNTs), and doxorubicin (DOX) have been simultaneously doped into the poly(ϵ-caprolactone) (PCL)/chitosan/zein core-shell nanofibers to increase its cytotoxicity for MCF-7 breast cancers killing. The physico-chemical properties of synthesized nanofibers were determined by scanning electron microscope, Fourier-transform infrared spectroscopy, tensile strength, and degradation rate determinations. The in vitro release studies demonstrated the sustained release of drugs from core-shell nanofibrous scaffold. The cytotoxicity and compatibility of core-shell nanofibers were investigated by their treating with MCF-7 breast cancer cells and L929 normal cells, respectively. PCL/PTX/chitosan/zein/MWCNTs/DOX core-shell nanofibers containing 1 wt% MWCNTs, 100 μg ml−1 DOX and 100 μg ml−1 PTX had a high biocompatibility with a 84% MCF-7 cancer cells killing. The in vivo studies revealed the synergic effects of MWCNTs and anticancer drugs on the tumor inhibition. This method could be considered as a new way for developing of MWCNTs loaded-nanofibers for cancer treatment in future. 相似文献
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The one-pot reactions of aryl glyoxals with acetylacetone and urea using molybdate sulfuric acid (5 mol %) lead to the novel functionalized 5-acetyl-4-(aryloyl)-3,4-dihydropyrimidinones, which readily undergo the Knorr condensation with hydrazines to produce new pyrimido[4,5-d]pyridazines. The present strategies are in accordance with green chemistry principles through the use of a safe and recyclable catalyst under solvent-free conditions. 相似文献
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Molecular Diversity - Herein, an effectual, quick and novel method is described for the synthesis of new triazolo[1,5-a]pyrimidine, triazolo[5,1-b][1,3] thiazine and pyrazolo[1,5-a]pyrimidine... 相似文献
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The effect of MHD on the total heat transfer from a porous fin attached to a vertical isothermal surface has been investigated. The Maxwell equations have been used, and also Rosseland approximation for radiation heat transfer and Darcy model for simulating the flow in porous medium have been adapted. The governing equations are reduced to a nonlinear ODE. The fin is supposed to be an infinite fin, which is exposed to a magnetic field. The dimensionless temperature profile, and the average Nusselt number profiles have been obtained for different Rayleigh numbers and porosities. Validation is carried out by comparing the results obtained in this study with those predicted by Darcy–Brinkman–Forchheimer model. 相似文献
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We present a study on the synthesis, characterization, and application of phthalhydrazide‐functionalized MCM‐41 (P‐MCM‐41) as a novel and efficient heterogeneous basic catalyst. The described catalyst was fully characterized via various techniques such as scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy dispersive X‐ray (EDX), X‐ray diffraction (XRD), and Fourier transform infrared (FT‐IR). P‐MCM‐41 efficiently catalyzed the four‐component reaction of arylaldehydes, Meldrum's acid, alkyl isocyanides, and isoquinoline in CHCl3 to prepare pyrrolo[2,1‐a]isoquinolines in good yields. 相似文献
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Jafari Saeid Dehghani Mohammad Nasirizadeh Navid Akrami Hamid Reza 《Mikrochimica acta》2017,184(11):4459-4468
Microchimica Acta - The article describes a sensor for the voltammetric determination of the azo dye Basic Red 13 (BR13) during its degradation by using sonoelectrochemistry in the presence of TiO2... 相似文献
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Sh. Khosravi E. Kourkchi R. Mansouri Y. Akrami 《General Relativity and Gravitation》2008,40(5):1047-1069
We present a new model universe based on the junction of FRW to flat Lemaitre–Tolman–Bondi (LTB) solutions of Einstein equations
along our past light cone, bringing structures within the FRW models. The model is assumed globally to be homogeneous, i.e.
the cosmological principle is valid. Local inhomogeneities within the past light cone are modeled as a flat LTB, whereas those
outside the light cone are assumed to be smoothed out and represented by a FRW model. The model is singularity free, always
FRW far from the observer along the past light cone, gives way to a different luminosity distance relation as for the CDM/FRW
models, a negative deceleration parameter near the observer, and correct linear and non-linear density contrast. As a whole,
the model behaves like a FRW model on the past light cone with a special behavior of the scale factor, Hubble and deceleration
parameter, mimicking dark energy.
Paper in honor of Bahram Mashhoon’s 60th birthday. 相似文献