An efficient, convenient and green method has been introduced for the preparation of 14-aryl（alkyl）-14H-dibenzo[a,j]xanthene and 1,8-dioxooctahydroxanthene derivatives by the reaction of aldehydes with 2-naphthol an...An efficient, convenient and green method has been introduced for the preparation of 14-aryl（alkyl）-14H-dibenzo[a,j]xanthene and 1,8-dioxooctahydroxanthene derivatives by the reaction of aldehydes with 2-naphthol and 5,5-dimethyl-1,3-cyclohexanedione, respectively, in the presence of ZrO（OTf）2 as a reusable catalyst under solvent-free conditions. In addition, very short reaction times, excellent yields, straightforward procedure, and relatively non-toxicity of the catalyst are other noteworthy advantages of the present method.展开更多
The tetrahydroquinoline moiety is a structural feature of many natural products. By using a domino reaction of aromatic amines and cyclic enol ethers catalyzed by zirconyl chloride in water, various tetrahydroquinolin...The tetrahydroquinoline moiety is a structural feature of many natural products. By using a domino reaction of aromatic amines and cyclic enol ethers catalyzed by zirconyl chloride in water, various tetrahydroquinoline derivatives were synthesized efficiently. Most cyclized products showed cis selectivity. The cis selectivity was tentatively rationalized due to chelation control in water.展开更多
This research was undertaken to study the effect of Zr-enhanced plasma electrolytic oxidation(PEO) as a pretreatment on the corrosion performance of epoxy coating applied on Magnesium in 3.5 wt.% Na Cl solution. The p...This research was undertaken to study the effect of Zr-enhanced plasma electrolytic oxidation(PEO) as a pretreatment on the corrosion performance of epoxy coating applied on Magnesium in 3.5 wt.% Na Cl solution. The parameters of delamination index along with coating damage index were extracted through electrochemical impedance spectroscopy(EIS) tests to determine how Zr may affect the corrosion protection of duplex PEO/epoxy coated samples. Pull-off adhesion tests were also accomplished to form a better understanding of Zr-enhanced PEO coating’ function. According to the obtained results, the presence of Zr can reduce the damage to the coating system by almost twice.展开更多
A novel catalyst, Zr (IV)-salen-MCM-41 with Lewis acid and base sites, was prepared and characterized by FT-IR, TG, XRD, SEM, TEM, BET, NH3-TPD, and CO_2-TPD. The as-synthesized catalyst was applied to the conversion ...A novel catalyst, Zr (IV)-salen-MCM-41 with Lewis acid and base sites, was prepared and characterized by FT-IR, TG, XRD, SEM, TEM, BET, NH3-TPD, and CO_2-TPD. The as-synthesized catalyst was applied to the conversion of fructose into 5-hydroxymethylfurfural (HMF). In this work, the heterogeneous catalyst had a superior activity for the dehydration of fructose into HMF. 92,0% HMF yield was obtained from fructose at 140 ℃ for 4 h in dimethyl sulfoxide (DMSO), In addition, the effect of reaction temperature, reaction time, solvents and catalyst dosages were also investigated in detail. Meanwhile, the Zr (IV)-salen-MCM-41 could be reused four times with a slight decrease in catalytic展开更多
Zirconyl-molybdopyrophosphate-tributyl phosphate （ZMPP-TBP） was a novel organic-inorganic composite adsorbent prepared by co-precipitation method and used in the adsorption of uranium from aqueous solution in batch ...Zirconyl-molybdopyrophosphate-tributyl phosphate （ZMPP-TBP） was a novel organic-inorganic composite adsorbent prepared by co-precipitation method and used in the adsorption of uranium from aqueous solution in batch adsorption experiments The as-obtained product was characterized using SEM, energy dispersive X-ray spectroscopy （EDX）, XRD and BET-N2 ad- sorption measurements. The study had been conducted to investigate the effects of solution pH, temperature, contact time, ini- tial concentration and coexisting ions. A maximum removal of 99.31% was observed for an initial concentration 5 mg/L, at pH 6.0 and an adsorbent dose of 1.0 g/L. The isothermal data were fitted with both Langmuir and Freundlich equations, but the data fitted the former better than the latter. According to the evaluation using the Langmuir equation, the maximum adsorption capacity of uranium （VI） was 196.08 mg/g at 293 K and pH 6.0. The pseudo-first-order kinetic model and pseudo-second-order kinetic model were used to describe the kinetic data, and the pseudo-second-order kinetic model was better. The thermody- namic parameter AG was calculated, the negative AG values of uranium （VI） at different temperature showed that the adsorption process was spontaneous. The good reusability of ZMPP-TBP also indicated that the ZMPP-TBP was a very promising adsorbent for uranium adsorption from aqueous solution.展开更多
Zirconyl pyrophosphate(ZrP_2O_7) was prepared and Cs adsorption behavior was studied.Results show that the distribution coefficient of Cs adsorption on ZrP_2O_7 was about 2800 mL/g.Ion exchange capacity of ZrP_2O_7 wa...Zirconyl pyrophosphate(ZrP_2O_7) was prepared and Cs adsorption behavior was studied.Results show that the distribution coefficient of Cs adsorption on ZrP_2O_7 was about 2800 mL/g.Ion exchange capacity of ZrP_2O_7 was0.35 mmol/g.In dynamic tests,Cs can be separated from other fission products very well by ZrP_2O_7.The ZrP_2O_7was stable both at high temperatures and in high concentration of nitric acid.The Cs adsorption by ZrP_2O_7 is a monolayer and chemical adsorption.展开更多
基金the Center of Excellence of Chemistry and Research Council of University of Isfahan for financial support of this work
文摘An efficient, convenient and green method has been introduced for the preparation of 14-aryl（alkyl）-14H-dibenzo[a,j]xanthene and 1,8-dioxooctahydroxanthene derivatives by the reaction of aldehydes with 2-naphthol and 5,5-dimethyl-1,3-cyclohexanedione, respectively, in the presence of ZrO（OTf）2 as a reusable catalyst under solvent-free conditions. In addition, very short reaction times, excellent yields, straightforward procedure, and relatively non-toxicity of the catalyst are other noteworthy advantages of the present method.
文摘The tetrahydroquinoline moiety is a structural feature of many natural products. By using a domino reaction of aromatic amines and cyclic enol ethers catalyzed by zirconyl chloride in water, various tetrahydroquinoline derivatives were synthesized efficiently. Most cyclized products showed cis selectivity. The cis selectivity was tentatively rationalized due to chelation control in water.
文摘This research was undertaken to study the effect of Zr-enhanced plasma electrolytic oxidation(PEO) as a pretreatment on the corrosion performance of epoxy coating applied on Magnesium in 3.5 wt.% Na Cl solution. The parameters of delamination index along with coating damage index were extracted through electrochemical impedance spectroscopy(EIS) tests to determine how Zr may affect the corrosion protection of duplex PEO/epoxy coated samples. Pull-off adhesion tests were also accomplished to form a better understanding of Zr-enhanced PEO coating’ function. According to the obtained results, the presence of Zr can reduce the damage to the coating system by almost twice.
基金financial supported by MOE & SAFEA,111 Project (No. B13025)
文摘A novel catalyst, Zr (IV)-salen-MCM-41 with Lewis acid and base sites, was prepared and characterized by FT-IR, TG, XRD, SEM, TEM, BET, NH3-TPD, and CO_2-TPD. The as-synthesized catalyst was applied to the conversion of fructose into 5-hydroxymethylfurfural (HMF). In this work, the heterogeneous catalyst had a superior activity for the dehydration of fructose into HMF. 92,0% HMF yield was obtained from fructose at 140 ℃ for 4 h in dimethyl sulfoxide (DMSO), In addition, the effect of reaction temperature, reaction time, solvents and catalyst dosages were also investigated in detail. Meanwhile, the Zr (IV)-salen-MCM-41 could be reused four times with a slight decrease in catalytic
基金supported by the National Natural Science Foundation of China (21276193)the National High-Tech Research & Development Program of China (863 Program+2 种基金 2012AA063504)the Tianjin Natural Science Foundation (2013F1-0033)Project of Ocean with Scientific Technology in Tianjin (KJXH2011-10)
文摘Zirconyl-molybdopyrophosphate-tributyl phosphate （ZMPP-TBP） was a novel organic-inorganic composite adsorbent prepared by co-precipitation method and used in the adsorption of uranium from aqueous solution in batch adsorption experiments The as-obtained product was characterized using SEM, energy dispersive X-ray spectroscopy （EDX）, XRD and BET-N2 ad- sorption measurements. The study had been conducted to investigate the effects of solution pH, temperature, contact time, ini- tial concentration and coexisting ions. A maximum removal of 99.31% was observed for an initial concentration 5 mg/L, at pH 6.0 and an adsorbent dose of 1.0 g/L. The isothermal data were fitted with both Langmuir and Freundlich equations, but the data fitted the former better than the latter. According to the evaluation using the Langmuir equation, the maximum adsorption capacity of uranium （VI） was 196.08 mg/g at 293 K and pH 6.0. The pseudo-first-order kinetic model and pseudo-second-order kinetic model were used to describe the kinetic data, and the pseudo-second-order kinetic model was better. The thermody- namic parameter AG was calculated, the negative AG values of uranium （VI） at different temperature showed that the adsorption process was spontaneous. The good reusability of ZMPP-TBP also indicated that the ZMPP-TBP was a very promising adsorbent for uranium adsorption from aqueous solution.
基金supported by the Defense Advanced Research Project
文摘Zirconyl pyrophosphate(ZrP_2O_7) was prepared and Cs adsorption behavior was studied.Results show that the distribution coefficient of Cs adsorption on ZrP_2O_7 was about 2800 mL/g.Ion exchange capacity of ZrP_2O_7 was0.35 mmol/g.In dynamic tests,Cs can be separated from other fission products very well by ZrP_2O_7.The ZrP_2O_7was stable both at high temperatures and in high concentration of nitric acid.The Cs adsorption by ZrP_2O_7 is a monolayer and chemical adsorption.
