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[en] In recent years, globalization of the world nuclear industry has developed into a new phase. Chinese nuclear industry will be inevitably integrated into this trend. Globalization will bring both positive and adverse effects on Chinese nuclear industry. Facing the fierce competition, Chinese companies must rise to many challenges to enter the global nuclear market. And China need to make scientific decisions and take effective measures in various fields of nuclear industry to realized the goal of global development. (authors)
[en] A highly selective molecularly imprinted adsorptive resin for ligustrazine was prepared by melamine-urea-formaldehyde (MUF) gel. In the experiments, two pieces of MUF gel were synthesized firstly; one was added ligustrazine hydrochloride as the template molecule in it to prepare the imprinted adsorptive resin, and the other was not. Scanning electron microscopy (SEM) revealed that both resins were the porous with a network structure whether or not it was added template molecule. The imprinted adsorptive resin had an absorbability of 85.22% measured by a 200 mg L-1 solution of ligustrazine hydrochloride at room temperature. The resin of MUF without template, on the other hand, displayed an adsorption capacity of almost zero. It illuminated the imprinted adsorptive resin formed ligustrazine recognition sites when the template molecule had been eluted. In the present paper, ligustrazine was effectively separated and enriched from herbs by using a solid-phase adsorptive column filled with the imprinted adsorptive resin. Its eluate, obtained from three kinds of solvents, was analyzed by GC-MS, and the results indicated that the imprinted adsorptive resin showed a high selectivity for ligustrazine. This is believed to be beneficial for extracting natural and highly purified ligustrazine
[en] Highlights: • Unique chrysanthemum-like Co_3O_4/Bi_2O_2CO_3 photocatalyst was synthesized by two-step hydrothermal process. • The Co_3O_4/Bi_2O_2CO_3 composites showed superior photocatalytic activity and stability. • The mechanism of the high performance was proposed as well. - Abstract: A hierarchical flower-like Co_3O_4/Bi_2O_2CO_3 composite photocatalyst with a p-n heterojunction semiconductor structure has been synthesized via two-step hydrothermal process. The composite photocatalyst have been characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM) and high-resolution transmission electron microscopy (HRTEM), BET surface area, UV–vis diffuse reflectance spectra (DRS), electron spin resonance (ESR) and photoluminescence spectroscopy (PL). The photocatalyst exhibits enhanced photocatalytic activity for methyl orange (MO) degradation under visible light irradiation. The ESR results reveal that the superoxide radicals (·O_2"−) were the main active species in the photocatalytic system. The 0.6 wt% Co_3O_4/Bi_2O_2CO_3 exhibits the highest photocatalytic activity as compared with other samples because of the formation of the p-n junction between p-Co_3O_4 and n-Bi_2O_2CO_3, which effectively suppresses the recombination of photoinduced electron-hole pairs and increase of the concentration of superoxide radicals (·O_2"−) involving in the photodegradation process. Moreover, the mechanism of the enhanced photocatalytic properties was proposed.