A unified computable formula is presented for the constant of inverse estimation emanating from stabilized finite element methods. The method lies in introducing an elementwise bubble space spanned by the interpolatio...A unified computable formula is presented for the constant of inverse estimation emanating from stabilized finite element methods. The method lies in introducing an elementwise bubble space spanned by the interpolation base functions with an additional bubble function given,and the parameter playing a stabilization role can take its value in a determined range.展开更多
Dicyandiamide(DICY) is a common ligand that exhibits low toxicity but can irritate the skin and eyes and cause methemoglobinemia on long-term exposure. Crystalline Cu-dicyandiamide(Cu-DICY) was obtained via facile syn...Dicyandiamide(DICY) is a common ligand that exhibits low toxicity but can irritate the skin and eyes and cause methemoglobinemia on long-term exposure. Crystalline Cu-dicyandiamide(Cu-DICY) was obtained via facile synthesis and its molecular structure and theoretical Raman spectra were simulated by using density functional theory(DFT). The results suggested that the Cu^(2+) coordinates with two H_2 O molecules and two different DICY molecules(an imino DICY and an amino DICY). The stability constants of Cu-DICY were calculated, and the electrochemical properties were studied. Two electrochemical redox processes occur in Cu-DICY in an aqueous solution: a reversible reaction with a formal potential of 0.2 V vs.MSE and an irreversible reaction between –0.4 and –1.2 V vs. MSE. The standard rate constant k0 for the reversible reaction was estimated to be 7.6×10^(-3) cm/s. In addition, based on the reversible reaction of Cu-DICY, square wave voltammetry was used to rapidly determine the concentration of Cu(II) and the detection limit was 66.7 μg/L, which satisfies the detection limit requirements for copper in tap water(2 mg/L) as provided by the World Health Organization.展开更多
文摘A unified computable formula is presented for the constant of inverse estimation emanating from stabilized finite element methods. The method lies in introducing an elementwise bubble space spanned by the interpolation base functions with an additional bubble function given,and the parameter playing a stabilization role can take its value in a determined range.
基金supported by the National Natural Science Foundation of China(21275030,21475023)the Program for Changjiang Scholars and Innovative Research Team in University(IRT_15R11)
文摘Dicyandiamide(DICY) is a common ligand that exhibits low toxicity but can irritate the skin and eyes and cause methemoglobinemia on long-term exposure. Crystalline Cu-dicyandiamide(Cu-DICY) was obtained via facile synthesis and its molecular structure and theoretical Raman spectra were simulated by using density functional theory(DFT). The results suggested that the Cu^(2+) coordinates with two H_2 O molecules and two different DICY molecules(an imino DICY and an amino DICY). The stability constants of Cu-DICY were calculated, and the electrochemical properties were studied. Two electrochemical redox processes occur in Cu-DICY in an aqueous solution: a reversible reaction with a formal potential of 0.2 V vs.MSE and an irreversible reaction between –0.4 and –1.2 V vs. MSE. The standard rate constant k0 for the reversible reaction was estimated to be 7.6×10^(-3) cm/s. In addition, based on the reversible reaction of Cu-DICY, square wave voltammetry was used to rapidly determine the concentration of Cu(II) and the detection limit was 66.7 μg/L, which satisfies the detection limit requirements for copper in tap water(2 mg/L) as provided by the World Health Organization.
