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排序方式: 共有177条查询结果,搜索用时 109 毫秒
101.
Shahnavaz Zohreh Khaligh Nader Ghaffari Mihankhah Taraneh Johan Mohd Rafie 《Research on Chemical Intermediates》2020,46(10):4645-4658
Research on Chemical Intermediates - A new ionic liquid is synthesized, and its chemical structure is characterized by FTIR, 1D NMR and 2D NMR, and mass analyses. The thermal behavior and thermal... 相似文献
102.
无溶剂条件下N-磺酸琥珀酰亚胺催化乙酰化反应(英文) 总被引:1,自引:0,他引:1
A small amount of succinimide-N-sulfonic acid efficiently catalyzed the acetylation of a variety alcohols, phenols, thiols, amines and aldehydes with acetic anhydride at room temperature under solvent free conditions. This catalyst has the advantages of excellent yields and short reaction times and the reaction can be carried out on a large scale, which makes it potentially useful for industrial applications. 相似文献
103.
Solmaz Ghaffari Jaleh Varshosaz Ismaeil Haririan Mohammad Reza Khoshayand Shirzad Azarmi 《Journal of Dispersion Science and Technology》2013,34(5):685-689
The aim of the present study was to develop controlled drug delivery systems based on nanotechnology. Two different nanocarriers were selected, chitosan-alginate nanoparticles as hydrophilic and solid lipid nanoparticles as lipophilic carriers. Nanoparticles were prepared and characterized by evaluating particle size, zeta potential, SEM pictures, DSC thermograms, percentage of drug loading efficiency, and drug release profile. The particle size of SLNs and Chi/Alg nanoparticles was 291 ± 5 and 520 ± 16. Drug loading efficiency of Chi/Alg and SLN particles were 68.98 ± 5.5% and 88 ± 4.5%. The drug release was sustained with chitosan-alginate system for about 45 hours whereas for SLNs >98% of the drug was released in 2 hours. Release profile did not change significantly after freeze drying of particles using cryoprotector. Results suggest that under in vitro condition chitosan/alginate systems can act as promising carriers for ciprofloxacin and may be used as an alternative system in sustained delivery of ciprofloxacin. 相似文献
104.
Elaheh Farajzadeh Oskuie Sajjad Azizi Zarrin Ghasemi Mahtab Pirouzmand Behnaz Nikzad Kojanag Jafar Soleymani 《Monatshefte für Chemie / Chemical Monthly》2020,151(2):243-249
The three-component Hantzsch condensation of various aryl aldehydes, dimedone, and methyl 3-aminocrotonate was investigated in the presence of MCM-41-supported ZnNO3. The polyhydroquinoline products which were obtained under mild conditions and very easy workup were evaluated for anti-cancer activities against MCF-7, SK-BR-3, and HT-29 of breast and colon cancer cells. The fluorescence emission of some products was also studied and their optical parameters were reported. 相似文献
105.
The influence of mixed convection boundary layer flow of a viscoelastic fluid over an isothermal horizontal circular cylinder has been analyzed. The boundary layer equations governing the problem are reduced to dimensionless nonlinear partial differential equations and then solved numerically using Keller-box method. Skin friction coefficient and Nusselt number are emphasized specifically. These quantities are displayed against curvature parameter. Effects of mixed convection parameter and radiation-conduction parameter on skin friction coefficient and Nusselt number are illustrated through graphs and table. The boundary layer separation points along the surface of cylinder are also calculated with/without radiation, and a comparison is shown. The presence of radiation helps to reduce the skin friction coefficient in opposing flow case and enhances it for assisting flow case. The increase in value of radiation-conduction parameter helps increase the value of skin friction coefficient and Nusselt number for viscoelastic fluids. The boundary layer separation delays due to thermal radiation. 相似文献
106.
This paper presents a novel and efficient protocol for the synthesis of pyrrolidinones using catalytic loading of 1,1'-butylenebis(3-sulfo-3H-imidazol-1-ium) hydrogen sulfate as a recyclable Brönsted acid ionic liquid through ball milling process at room temperature under solvent-free conditions. The developed method provides good to excellent yields of various pyrrolidinones in environmentally friendly conditions. Furthermore, this efficient protocol displays a combination of the synthetic advantage of one-pot multicomponent reaction with ecological benefits and convenience of a mechanochemical procedure. 相似文献
107.
The Baeyer-Villiger oxidation of 1 in chloroform with perbenzoic acid yielded 3,4, 5, 7 and 8. Similarly, the ketone 2 provided 9 and 10. The mechanism involved in the formation of abnormal Baeyer-Villiger products has been suggested. 相似文献
108.
Ali Akbar Moshfegh Behnaz Mazandarani Azarmidokht Nahid Gholam Hosein Hakimelahi 《Helvetica chimica acta》1982,65(4):1229-1232
A short synthesis of the title compounds is reported. Most of the compounds prepared were found to be active against a number of pathogenic microorganisms in vitro. 相似文献
109.
Ehsan Moaseri Majid Karimi Behnaz Bazubandi Majid Baniadam Morteza Maghrebi 《Polymer Science Series A》2017,59(5):726-733
Alignment of multi-walled carbon nanotubes (MWCNTs) in a bulk epoxy matrix was studied using a magnetic-assisted method. In this study, the applicability of solenoid magnetic field was compared to that of static magnetic field, which has recently been published. It has been found that solenoid magnetic field is able to provide better alignment of MWCNTs due to the uniform magnetic field along the axis of solenoid. Remarkable improvements were achieved in the mechanical properties of aligned MWCNT-reinforced epoxy composites. Alignment of MWCNTs was clearly observed in all regions of the composites by scanning electron microscopy and transmission electron microscopy. 相似文献
110.
Hamid R. Ghaffari Dionne M. Aleman David A. Jaffray Mark Ruschin 《Journal of Global Optimization》2017,69(1):103-115
Although the use of mathematical optimization techniques can greatly improve the quality of treatment plans in various radiation therapy treatment settings, one complication is the potentially clinically unrealistic nature of optimized treatments. The difficulty arises from two factors: (1) machine limitations that govern the minimum amount of radiation delivery time, and (2) long treatment times due to the complexity of optimized treatments. In the first scenario, if a particular configuration of the radiation delivery device is used, then it typically must deliver radiation for a minimum length of time. Incorporation of such requirements in a mathematical model generally requires additional constraints and binary variables, increasing the difficulty of the optimization. In the second scenario, mathematically optimized treatments commonly assign (small amounts of) radiation to be delivered from many configurations, drastically increasing the time needed to deliver the treatment (beam-on time). We examine these two issues within the penalty-based sector duration optimization model for Leksell Gamma Knife\(^{\textregistered }\) Perfexion\(^{\mathrm{TM}}\) (Elekta, Stockholm, Sweden) and the combined sector duration and isocentre optimization model to reduce beam-on time and to ensure that machine limitations regarding delivery times are met. 相似文献