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101.
Fatemeh Khodadadi Azadboni 《等离子体物理论文集》2021,61(3):e202000135
The presence of Weibel instability in laser-irradiated fuel could be detrimental to the process of ablative implosion, which is necessary for achieving thermonuclear fusion reactions. In this paper, the effect of the Coulomb collisional within the turbulent plasma on the Weibel instability growth rate has been investigated for linear and circular polarization. The results indicate that the Weibel instability growth rate at circular polarization near the ignition centre of the fuel fusion (collisional plasma) is about 105 times higher than the collisional Weibel instability growth rate at linear polarization. The Weibel instability growth rate is observed near the critical density of the fuel fusion (collisionless plasma) at linear polarization and enhancement near the foot of the heat in front of the fuel fusion. By increasing the steps of the density gradient plasma in the low-density corona, electromagnetic instability occurs at a higher stress flow. Therefore, the deposition condition of electron beam energy in circular polarization of turbulent plasma can be shifted to the fuel core for suitable ignition. 相似文献
102.
Mostafa Kiamehr Batoul Alipour Leyla Mohammadkhani Behzad Jafari Peter Langer 《Tetrahedron》2017,73(21):3040-3047
Various novel polycyclic thiopyranoindol annulated [3,4-c]quinolone derivatives were synthesized via domino Knoevenagel-hetero-Diels–Alder reactions of indoline-2-thions and novel N-acrylated anthranilaldehydes in refluxing ethanol as a solvent in the presence of 20 mol% ZnBr2 as a Lewis acid catalyst. All reactions proceed with high yields with excellent regio- and stereoselectivity. 相似文献
103.
This paper provides an analytical approach for obtaining bounds on elastic stress concentration factors in the theory of finite anti-plane shear of homogeneous, isotropic, incompressible materials. The problem of an infinite slab with traction-free elliptical cavity subject to a state of finite simple shear deformation is considered. Explicit estimates are obtained for the maximum shear stress in terms of the cavity geometry, applied stress at infinity and constitutive parameters. The analysis is based on application of maximum principles for second-order quasilinear uniformly elliptic equations. 相似文献
104.
Bamoharram Fatemeh F Roshani Mina Heravi Majid M Mahdavi Masoumeh Javid Ali Emampour Jalal Sh 《中国化学》2010,28(6):974-976
Isoxazolo[5,4‐d]pyrimidine‐4,6(5H,7H)diones 2a – 2f have been synthesized from the reaction of ethyl 5‐amino‐3‐methyl‐4‐isoxazole carboxylate ( 1 ) with aryl isocyanates in the presence of Keggin heteropolyacid H3[PW12O40] as a green solid acid catalyst at room temperature in a one‐pot process in good yields. 相似文献
105.
<正>4,6-Diarylpyrimidin-2(1H)-one derivatives have been synthesized from three-component one-pot condensation of acetophe-none derivatives,aldehydes and urea in the presence of trimethylsilyl chloride and a catalytic amount of H_3PMo_(12)O_(40)under solvent-free conditions. 相似文献
106.
107.
Susan Sadeghi Fatemeh Fathi 《Journal of inclusion phenomena and macrocyclic chemistry》2010,67(1-2):91-98
A new PVC membrane coated graphite electrode for cesium ion based on 4′,4″(5′)di–tert-butyl di-benzo-18-crown-6 (DTBDB18C6) as ionophore was prepared. The electrode shows a near Nernstian response of 57.0 ± 1.8 mV decade?1 over a wide activity range of 6.0 × 10?6–1.0 × 10?1 mol L?1 with a limit of detection 4.0 × 10?6 mol L?1. The proposed electrode is suitable for use in aqueous solution in the pH range of 3.0–9.5. It has a fast response time of 10 s and can be used for at least 1 month without any considerable divergence in potential. The selectivity coefficients for Cs+ ion with respect to ammonium, alkali, alkaline earth and some selected transition metal ions were determined and showed a superior selectivity over Li+, Na+ and alkaline earth metal ions. The new electrode was applied for determination of Cs+ in spiked tap water. The electrode was also used as indicator electrode in potentiometric titration of Cs+ with sodium tetraphenyl borate. 相似文献
108.
A reversed-phase dispersive liquid-liquid microextraction (RP-DLLME) method was developed for the preconcentration and direct HPLC determination of oleuropein in olive's processing wastewater (OPW) and olive leaves extracts. In conventional DLLME, the sedimented phase is a micro-drop of a chlorinated organic solvent that is not compatible with RP-HPLC. Therefore, solvent evaporation and reconstitution with an appropriate solvent is often required. In RP-DLLME, this problem was overcome by overturning the solvent polarity in the ordinary DLLME and replacing the organic solvent with water. A central composite chemometrics design was used for multivariate optimization of the effects of five different parameters influencing the extraction efficiency of the method. In the optimized conditions, a mixture of 1.4 mL of an ethyl acetate extract of sample and 40 μL water (pH 5.0) was rapidly injected into 5.3 mL of cyclohexane. After centrifugation of the formed cloudy mixture, a micro-drop of the aqueous phase was sedimented at the conical bottom of the centrifuge tube. This phase, that contained the preconcentrated and partially purified analyte, was directly injected into an RP-HPLC column for analysis. A mean extraction recovery of 102.5 (±4.5) % with enrichment factors exceeding 38, was obtained for five replicated analysis. The detection limit of the method (3σ) for OE was 0.02 μg L−1 for OPW and 2 × 10−3 mg kg−1 for olive leaves samples. The results showed that, RP-DLLME is a promising technique which is quick, easily operated and can be directly coupled to HPLC. 相似文献
109.
A sensitive adsorptive cathodic stripping voltammetry with H‐point standard addition method for simultaneous determination of uranium and cadmium has been developed. The trace amounts of these metal ions can be simultaneously determined using the Levodpa as complexing agent. Optimal conditions were: accumulation time 50 s, accumulation potential 0.0 mV, scan rate 40 mV s?1, supporting electrolyte 0.1 M ammonium buffer pH 9.6, and 1×10?5 M of Levodopa. The results revealed that the cadmium and uranium could be simultaneously determined by H‐point standard addition method with different concentration ratios of uranium to cadmium. The method was successfully applied in a several of real samples. 相似文献
110.
Zahra Talebpour Mehregan Safari Fatemeh Molaabaci Ali Alizadeh Hassan Y. Aboul-Enein 《Chromatographia》2010,72(7-8):707-712
A novel poly(methyl methacrylate–ethyleneglycol dimethacrylate–acrylic acid) film has been introduced for coating on stir bars to sorptive extraction (SBSE). The effects of different contents of porogen, monomer, cross-linker, modifier and initiator during the solvent or bulk polymerization step on the mechanical property and solvent resistant of prepared sorptive stir bars were investigated. The evaluation of results were caused to obtain the four prepared sorptive stir bars with good mechanical stability and excellent resistance to organic solvents. The extraction efficiency of these prepared sorptive stir bars were investigated by liquid desorption-liquid chromatography-ultraviolet detection (LD-LC-UV) using N-Nitrosodiphenylamine as target analyte. SBSE assays showed the sorptive stir bar that prepared using solution polymerization method had the better recovery for N-Nitrosodiphenylamine in water samples. This sorptive stir bar showed good linearity and acceptable recoveries, as well as advantages such as sensitivity, simplicity, low cost and high feasibility. Based on atomic force microscopy (AFM) results, the average pore size of optimum prepared stir bar using solvent polymerization method was obtained ~9 nm. The thermal gravity (TG) and differential scanning calorimetric (DSC) results showed this polyacrylate film has high thermal stability. 相似文献