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991.
以自制SBS-g-(AA/StSO3Na)/SBS-g-DMAEMA双极膜作电解槽阴阳两极室的隔膜,借助正交试验确定阴极电还原氧气产生过氧化氢的最优条件,进而利用钨酸钠/过钨酸钠体系由阴极间接电氧化红曲红制备红曲黄色素.实验表明:以石墨作电极,阳极液为10%硫酸溶液,阴极液为0.5g·L-1红曲红丙酮水溶液,添加钨酸钠(浓度15mmol/L),调节pH至3,在通氧速率65cm3/min,电流密度5.78mA.cm-2下电解2h,阴极平均电流效率可达72.39%.电解产物经红外表征和紫外跟踪分析,证实了红曲红烯键环氧化反应的发生. 相似文献
992.
Mandelstam’s argument that PCAC follows from assigning Lorentz quantum numberM=1 to the massless pion is examined in the context of multiparticle dual resonance model. We construct a factorisable dual
model for pions which is formulated operatorially on the harmonic oscillator Fock space along the lines of Neveu-Schwarz model.
The model has bothm
π andm
ϱ as arbitrary parameters unconstrained by the duality requirement. Adler self-consistency condition is satisfied if and only
if the conditionmϱ2−mπ2=1/2 is imposed, in which case the model reduces to the chiral dual pion model of Neveu and Thorn, and Schwarz. The Lorentz
quantum number of the pion in the dual model is shown to beM=0. 相似文献
993.
We consider fermionic dense matter under a magnetic field, where fermions couple minimally to gauge fields, and calculate anomalous currents at one loop. We find anomalous currents are spontaneously generated along the magnetic field but fermions only in the lowest Landau level contribute to anomalous currents. We then show that there are no more corrections to the anomalous currents from two or higher loops. 相似文献
994.
995.
** Email: marian.slodicka{at}ugent.be This paper is devoted to the study of a non-linear degeneratetransient eddy current model of the type [graphic: see PDF] for some 0 < < 1 subject to homogeneous Dirichlet boundarycondition H x = 0. Here, the magnetic properties of a softferromagnet are linked by a power material law. The well-posednessof the problem is proved and a non-linear time-discrete numericalscheme for the approximation in suitable function spaces isdesigned. Convergence of the approximation to a weak solutionis proved and error estimates are derived. 相似文献
996.
997.
998.
Numerical simulation results are presented for a drift-diffusion rate equation model which describes electronic transport due to sequential tunneling between adjacent quantum wells in weakly coupled semiconductor superlattices (SLs). The electron dynamics is dependent on the external magnetic field perpendicular to the electron motion direction, and a detailed explanation is given. Using different parameters, the system shows different dynamic behaviors, and three distinct phenomena are observed and controlled by increasing magnetic field. (i) For a lower doping density, the system state transfers from stable state to oscillationary state. (ii) An opposite result is obtained to that in the case (i) for an intermediate value of the doping density, and the state changes from oscillationary to stationary. (iii) The state varies between oscillationary and stationary when doping density is large. Then, a detailed theoretical analysis is given to explain these surprise phenomena. The distribution of the electric-field domain along the SLs is plotted. We find the structure of the domain is almost uniform for a lower doping density, and no domain occurs in the SLs. By adding an external ac signal, complex nonlinear behaviors are observed from the Poincaré map and the corresponding phase diagrams when the driving frequency changes. 相似文献
999.
We investigated the transport characteristics of Rabi oscillations, by using numerical methods, within a two-band tight-binding model driven by dc-ac electric fields. We found that Rabi oscillations make the long-time average current a sharply change, i.e. the current have resonant peaks appearing. Rabi oscillations are destroyed by dephasing; these peaks are the signatures of Rabi oscillations on the current response. The strong interband coupling will change the conditions of Rabi oscillations and, correspondingly, changes the places where the current resonant peaks appear. 相似文献
1000.
《Arabian Journal of Chemistry》2023,16(4):104607
Direct current (DC) electrocoagulation has obvious decolorization effect on indigo dyeing wastewater produced in actual production, while the removal rate of chemical oxygen demand (COD) was less than 40%, accompanied by serious electrode corrosion and high energy consumption. In order to enhance the COD removal rate, reduce the electrode loss and power consumption, a peroxi-alternating current (AC) electrocoagulation (EC) system was constructed. With COD as the main evaluation index, the effects of power type, electrode combination and process parameters on COD removal rate and decolorization rate were focused on and explored, as well as revealing the degradation mechanism of COD. The results showed that AC electrocoagulation enhanced the floc adsorption capacity by improving the floc structure, and the COD removal rate after treatment was 51.19%. The coupled system of peroxi-AC electrocoagulation further removed sulfite and residual dyes in the wastewater, and the COD removal and decolorization rate of the treated wastewater reached 78.09% and 98.47%, respectively. In addition, the specific energy consumption analysis of COD removal showed that the coupled system was far less energetic than the DC electrocoagulation process, with only 30% of its energy consumption. The uniform corrosion of the electrode under the action of AC weakened the passivation, which reduced the electrode loss and power consumption by 22.73% and 43.75%, respectively. Results from the present work indicated that the peroxi-AC EC system could be an effective method for reducing the concentration of COD in indigo dyeing wastewater. 相似文献