排序方式: 共有122条查询结果,搜索用时 15 毫秒
81.
Nazarimehr Fahimeh Hosseini Seyedeh Sanaz Khalaf Abdul Jalil M. Jafari Sajad Sprott Julien C. 《The European physical journal. Special topics》2020,229(6-7):921-927
The European Physical Journal Special Topics - This paper proposes a behavioral model for cells that shows their different dynamics from a high pluripotent stem cell to any distinct cell fate. The... 相似文献
82.
83.
84.
Nanostructured Conducting Polymer/Copper Oxide as a Modifier for Fabrication of L‐DOPA and Uric Acid Electrochemical Sensor 下载免费PDF全文
A modified electrode was prepared by modification of the carbon paste electrode (CPE) with a nanostructured material. This nanostructure with electrocatalytic activity was synthesized by combination of poly pyrrole and copper oxide nanoparticles (PPy/CuO). The structure and morphology of PPy/CuO was studied. The fabricated modified electrode (CPE‐PPy/CuO) exhibited an excellent electrocatalytic activity toward levodopa (L‐DOPA) and uric acid (UA) oxidation because of high conductivity, low electron transfer resistance and catalytic effect. The CPE‐PPy/CuO had a lower overvoltage and enhanced electrical current with respect to the bare CPE for both L‐DOPA and UA. Also, the modified electrode showed a good resolution for the overlapped anodic peaks of L‐DOPA and UA. This electrode was used for the successful simultaneous determination of L‐DOPA and UA. The electrochemical sensor responded to L‐DOPA and UA in the concentration range of 0.050–1200 μM and 0.040–2000 μM, respectively. The detection limits were obtained by differential pulse voltammetry as 15 nM for L‐DOPA and 20 nM for UA. Finally, the proposed electrode was used for determination of L‐DOPA and UA in real samples using standard addition method. 相似文献
85.
Sajad Asadizadeh Shahabodin Ayatollahi 《Journal of Dispersion Science and Technology》2013,34(10):1479-1487
AbstractA new polymer gel nanocomposite is fabricated for excess water production control (water shut off) in petroleum reservoirs and its rheological behavior is evaluated in the presence of sea water and formation water at the temperature of 100?°C. It is shown that at a high salinity without using SiO2 nanoparticles, the elastic modulus of synthesized polymer gel in the presence of sea water and formation water are 12.5?Pa and 9.8?Pa respectively. However by incorporation of SiO2 nanoparticles in the polymer gel matrix, the elastic modulus of synthesized polymer gel in the presence of sea water and formation water can be improved to 13.56?Pa and 11.57?Pa respectively, which is quite interesting from reservoir engineering viewpoint. Equilibrium Swelling Ratio (ESR) of the nanocomposite polymer gel in sea water and formation water decreases as the concentration of the SiO2 increases. Thermal stability of the polymer gel is investigated by differential scanning calorimetry (DSC) measurements. The inflexion temperature of the polymer gel is improved by incorporation of 2000?ppm SiO2 nanoparticles. The fabricated polymer gel nanocomposite in this work can have potential application in reduction of excess water production during enhanced oil recovery (EOR) operations in petroleum industry. 相似文献
86.
Malek Taher Maghsoodlou Sayyed Mostafa Habibi-Khorassani Reza Heydari Nourallah Hazeri Seyed Sajad Sajadikhah Mohsen Rostamizadeh 《Arabian Journal of Chemistry》2011,4(4):481-485
An efficient and direct protocol is described for the preparation of α-amino phosphonates derivatives by employing a multi-component, one-pot condensation reaction of aldehyde, amine and trialkyl phosphite in the presence of silica-supported perchloric acid (3 mol%) under solvent-free conditions. The thermal solvent-free green procedure offers advantages such as shorter reaction time, simple work-up, high yield, recovery and reusability of catalyst. 相似文献
87.
Bulk homopolymerization and copolymerization of 1‐hexene (H) with polar monomers including butyl acrylate (B) and methyl methacrylate (M) in the presence of 1,4‐bis (2,6‐diisopropylphenyl) acenaphthene diimine nickel (II) dibromide catalyst were investigated. Two cocatalysts, including diethyl aluminium chloride (DEAC) and ethyl aluminium sesqui chloride (EASC), were used to activate the catalyst at ambient temperature. In both the homopolymerization and copolymerization of 1‐hexene with polar monomers, the catalyst activity resulted from EASC as cocatalyst was higher than that resulted from DEAC. 1HNMR analysis was used in order to determine incorporation level of polar monomers and branching density of the synthesized polymers. A highest incorporation level of 13.3% mol was obtained using monomer B in the presence of the cocatalyst EASC. In addition, the influence of polar monomers on molecular weight and molecular weight distribution (PDI) was studied for both the homo‐ and co‐polymerizations of 1‐hexene in the presence of various cocatalysts. A higher molecular weight and narrower PDI were obtained by using the DEAC cocatalyst compared to the EASC cocatalyst. Glass transition temperature (Tg) and melting point (Tm) of the synthesized polymers were found to be dependent on the cocatalyst type and comonomer incorporation level. The addition of dichloromethane solvent into reaction medium showed a positive effect on comonomer incorporation which could not be seen in bulk polymerization. However, the presence of dichloromethane led to decrease the catalyst activity and molecular weight of the polymers. 相似文献
88.
This topical issue collects contributions of recent achievements and scientific progress related to the connection between nonlinear dynamics and life sciences. The individual papers focus on different questions of present day interest in both theoretical and applied aspects of nonlinear dynamics in applied to life sciences. 相似文献
89.
Chemistry of Heterocyclic Compounds - This microreview focuses on the recently published literature in 2013–2018 for the synthesis of thiophene derivatives based on isothiocyanates as key... 相似文献
90.
Chemistry of Heterocyclic Compounds - The microreview considers recent methodologies for the synthesis of 2H-thiochromenes including enantioselective synthesis, multistep synthesis,... 相似文献