Phenolic compounds exist in crude oil as pollutants, and their removal is vital important for the refining and further application of oils. In traditional separation approaches, strong acid and strong base have to be ...Phenolic compounds exist in crude oil as pollutants, and their removal is vital important for the refining and further application of oils. In traditional separation approaches, strong acid and strong base have to be used to remove these compounds, which may cause serious environmental problems. In this work, 19 kinds of cholinium ionic liquids have been developed to separate phenol from model oil by liquid–liquid extraction. Structural effect of anions of the ionic liquids in the separation is systematically investigated. It is found that depending on the chemical structure of ionic liquids, phenol can be removed from toluene with single-step removal efficiency from 86 to 99% under optimal conditions. The type of substituent groups and the-CH_2 number between two carboxylates have obvious effect on the removal efficiency, and more hydrophilic ionic liquids have a stronger extraction performance for phenol. Furthermore, thermodynamic,^(13) C NMR,~1 H NMR and density functional theory calculations have been performed to characterize the extraction process and to understand the extraction mechanism. It is shown that the extraction of phenol from oil to ionic liquid is a favorable process, and this process is mainly driven by enthalpy change. The formation of the hydrogen bond between anion of the ionic liquid and-OH of phenol is the main driving force for the extraction of phenol from oil to the ionic liquids.展开更多
Choline-based ionic liquids(Ch-ILs) with anions possessing interacting sites to attract CO_2 were designed, which could capture CO_2 with capacity >1.0 mol CO_2 per molar IL under ambient conditions. Moreover, this...Choline-based ionic liquids(Ch-ILs) with anions possessing interacting sites to attract CO_2 were designed, which could capture CO_2 with capacity >1.0 mol CO_2 per molar IL under ambient conditions. Moreover, this kind of ILs combining with Cu Cl could catalyze the formylation of amines with CO_2/H_2 at 120 °C. Especially, choline imidazolate showed the best performance,affording a series of N-formamides in excellent yields. It was demonstrated that the IL activated CO_2 and the synergistic effect between the IL and Cu Cl resulted in the high activity for catalysing the formylation of amines with CO_2/H_2.展开更多
Pyridine-containing anion-based ionic liquids(PA-ILs) with two kinds of interaction sites to bind CO_2, e.g., [P4444][2-OP], were found to be highly efficient for catalysing the cycloaddition reactions of atmospheric ...Pyridine-containing anion-based ionic liquids(PA-ILs) with two kinds of interaction sites to bind CO_2, e.g., [P4444][2-OP], were found to be highly efficient for catalysing the cycloaddition reactions of atmospheric CO_2 with epoxides at room temperature under metal-and halogen-free conditions, producing a series of cyclic carbonates in high yields. It was demonstrated that the cooperative interaction from two interaction sites in the anions of PA-ILs activated CO_2, while the cation activated the epoxides substrates via coordination to the central P+ unit, thus resulting in the high activity of the IL catalysts.展开更多
This paper presents the results of nonlinear finite element analyses conducted on stainless steel shear links. Stainless steels are attractive materials for seismic fuse device especially for corrosion-aware environme...This paper presents the results of nonlinear finite element analyses conducted on stainless steel shear links. Stainless steels are attractive materials for seismic fuse device especially for corrosion-aware environment such as coastal regions because they are highly corrosion resistant, have good ductility and toughness properties in combination with low maintenance requirements. This paper discusses the promising use ofAISI 316L stainless steel for shear links as seismic fuse devices. Hysteresis behaviors of four stainless steel shear link specimens under reversed cyclic loading were examined to assess their ultimate strength, plastic rotation and failure modes. The nonlinear finite element analysis results show that shear links made of AISI 316L stainless steel exhibit a high level of ductility. However, it is also found that because of large over-strength ratio associated with its strain hardening process, mixed shear and flexural failure modes were observed in stainless steel shear links compared with conventional steel shear links with the same length ratio. This raises the issue that proper design requirements such as length ratio, element compactness and stiffener spacing need to be determined to ensure the full development of the overall plastic rotation of the stainless steel shear links.展开更多
Eco-friendly printing is important for mass manufacturing of thin-film photovoltaic(PV)devices to preserve human safety and the environment and to reduce energy consumption and capital expense.However,it is challengin...Eco-friendly printing is important for mass manufacturing of thin-film photovoltaic(PV)devices to preserve human safety and the environment and to reduce energy consumption and capital expense.However,it is challenging for perovskite PVs due to the lack of eco-friendly solvents for ambient fast printing.In this study,we demonstrate for the first time an eco-friendly printing concept for high-performance perovskite solar cells.Both the perovskite and charge transport layers were fabricated from eco-friendly solvents via scalable fast blade coating under ambient conditions.The perovskite dynamic crystallization during blade coating investigated using in situ grazing incidence wide-angle X-ray scattering(GIWAXS)reveals a long sol-gel window prior to phase transformation and a strong interaction between the precursors and the eco-friendly solvents.The insights enable the achievement of high quality coatings for both the perovskite and charge transport layers by controlling film formation during scalable coating.The excellent optoelectronic properties of these coatings translate to a power conversion efficiency of 18.26%for eco-friendly printed solar cells,which is on par with the conventional devices fabricated via spin coating from toxic solvents under inert atmosphere.The eco-friendly printing paradigm presented in this work paves the way for future green and highthroughput fabrication on an industrial scale for perovskite PVs.展开更多
Dry-deposited particles were collected during the passage of an extremely strong dust storm in March, 2010 at a coastal site in Qingdao（36.15°N, 120.49°E）, a city located in Eastern China. The size, morpho...Dry-deposited particles were collected during the passage of an extremely strong dust storm in March, 2010 at a coastal site in Qingdao（36.15°N, 120.49°E）, a city located in Eastern China. The size, morphology, and elemental composition of the particles were quantified with a scanning electron microscope equipped with an energy dispersive X-ray instrument（SEM–EDX）. The particles appeared in various shapes, and their size mainly varied from 0.4to 10 μm, with the mean diameters of 0.5, 1.5, and 1.0 μm before, during, and after the dust storm, respectively. The critical size of the mineral particles settling on the surface in the current case was about 0.3–0.4 μm before the dust storm and about 0.5–0.7 μm during the dust storm. Particles that appeared in high concentration but were smaller than the critical size deposited onto the surface at a small number flux. The elements Al, Si and Mg were frequently detected in all samples, indicating the dominance of mineral particles. The frequency of Al in particles collected before the dust storm was significantly lower than for those collected during and after the dust storm. The frequencies of Cl and Fe did not show obvious changes, while those of S, K and Ca decreased after the dust arrival. These results indicate that the dust particles deposited onto the surface were less influenced by anthropogenic pollutants in terms of particle number.展开更多
基金supported by the National Natural Science Foundation of China(No.21803017,21733011)the National Key Research and Development Program of China(2017YFA0403101)+2 种基金S&T Research Foundation of Education Department of Henan Province(No.19A150027)the 111 project(No.D17007)the Open Research Fund of Shanghai Key Laboratory of Green Chemistry and Chemical Processes
文摘Phenolic compounds exist in crude oil as pollutants, and their removal is vital important for the refining and further application of oils. In traditional separation approaches, strong acid and strong base have to be used to remove these compounds, which may cause serious environmental problems. In this work, 19 kinds of cholinium ionic liquids have been developed to separate phenol from model oil by liquid–liquid extraction. Structural effect of anions of the ionic liquids in the separation is systematically investigated. It is found that depending on the chemical structure of ionic liquids, phenol can be removed from toluene with single-step removal efficiency from 86 to 99% under optimal conditions. The type of substituent groups and the-CH_2 number between two carboxylates have obvious effect on the removal efficiency, and more hydrophilic ionic liquids have a stronger extraction performance for phenol. Furthermore, thermodynamic,^(13) C NMR,~1 H NMR and density functional theory calculations have been performed to characterize the extraction process and to understand the extraction mechanism. It is shown that the extraction of phenol from oil to ionic liquid is a favorable process, and this process is mainly driven by enthalpy change. The formation of the hydrogen bond between anion of the ionic liquid and-OH of phenol is the main driving force for the extraction of phenol from oil to the ionic liquids.
基金supported by the Chinese Academy of Sciences (QYZDY-SSW-SLH013)the National Natural Science Foundation of China (21673068, 21533011)
文摘Choline-based ionic liquids(Ch-ILs) with anions possessing interacting sites to attract CO_2 were designed, which could capture CO_2 with capacity >1.0 mol CO_2 per molar IL under ambient conditions. Moreover, this kind of ILs combining with Cu Cl could catalyze the formylation of amines with CO_2/H_2 at 120 °C. Especially, choline imidazolate showed the best performance,affording a series of N-formamides in excellent yields. It was demonstrated that the IL activated CO_2 and the synergistic effect between the IL and Cu Cl resulted in the high activity for catalysing the formylation of amines with CO_2/H_2.
基金supported by the National Natural Science Foundation of China(21403252,21533011)the Chinese Academy of Sciences(QYZDY-SSW-SLH013)
文摘Pyridine-containing anion-based ionic liquids(PA-ILs) with two kinds of interaction sites to bind CO_2, e.g., [P4444][2-OP], were found to be highly efficient for catalysing the cycloaddition reactions of atmospheric CO_2 with epoxides at room temperature under metal-and halogen-free conditions, producing a series of cyclic carbonates in high yields. It was demonstrated that the cooperative interaction from two interaction sites in the anions of PA-ILs activated CO_2, while the cation activated the epoxides substrates via coordination to the central P+ unit, thus resulting in the high activity of the IL catalysts.
文摘This paper presents the results of nonlinear finite element analyses conducted on stainless steel shear links. Stainless steels are attractive materials for seismic fuse device especially for corrosion-aware environment such as coastal regions because they are highly corrosion resistant, have good ductility and toughness properties in combination with low maintenance requirements. This paper discusses the promising use ofAISI 316L stainless steel for shear links as seismic fuse devices. Hysteresis behaviors of four stainless steel shear link specimens under reversed cyclic loading were examined to assess their ultimate strength, plastic rotation and failure modes. The nonlinear finite element analysis results show that shear links made of AISI 316L stainless steel exhibit a high level of ductility. However, it is also found that because of large over-strength ratio associated with its strain hardening process, mixed shear and flexural failure modes were observed in stainless steel shear links compared with conventional steel shear links with the same length ratio. This raises the issue that proper design requirements such as length ratio, element compactness and stiffener spacing need to be determined to ensure the full development of the overall plastic rotation of the stainless steel shear links.
基金supported by the National Key Research and Development Program of China(2016YFA0202403,2017YFA0204800)the Key Program Project of the National Natural Science Foundation of China(51933010)+4 种基金the National Natural Science Foundation of China(61974085)the National University Research Fund(GK201802005)the 111 Project(B14041)the National 1000-Talent-Plan Program(1110010341)CHESS is supported by the NSF Award DMR-1332208.
文摘Eco-friendly printing is important for mass manufacturing of thin-film photovoltaic(PV)devices to preserve human safety and the environment and to reduce energy consumption and capital expense.However,it is challenging for perovskite PVs due to the lack of eco-friendly solvents for ambient fast printing.In this study,we demonstrate for the first time an eco-friendly printing concept for high-performance perovskite solar cells.Both the perovskite and charge transport layers were fabricated from eco-friendly solvents via scalable fast blade coating under ambient conditions.The perovskite dynamic crystallization during blade coating investigated using in situ grazing incidence wide-angle X-ray scattering(GIWAXS)reveals a long sol-gel window prior to phase transformation and a strong interaction between the precursors and the eco-friendly solvents.The insights enable the achievement of high quality coatings for both the perovskite and charge transport layers by controlling film formation during scalable coating.The excellent optoelectronic properties of these coatings translate to a power conversion efficiency of 18.26%for eco-friendly printed solar cells,which is on par with the conventional devices fabricated via spin coating from toxic solvents under inert atmosphere.The eco-friendly printing paradigm presented in this work paves the way for future green and highthroughput fabrication on an industrial scale for perovskite PVs.
基金supported by the National Basic Research Program of China (No.2013CB228503)the National Natural Science Foundation of China (Nos.91544214,21190052,41121004,41541038)the Education Bureau of Hebei Province for Excellent Young Scholars (No.YQ2014020)
文摘Dry-deposited particles were collected during the passage of an extremely strong dust storm in March, 2010 at a coastal site in Qingdao（36.15°N, 120.49°E）, a city located in Eastern China. The size, morphology, and elemental composition of the particles were quantified with a scanning electron microscope equipped with an energy dispersive X-ray instrument（SEM–EDX）. The particles appeared in various shapes, and their size mainly varied from 0.4to 10 μm, with the mean diameters of 0.5, 1.5, and 1.0 μm before, during, and after the dust storm, respectively. The critical size of the mineral particles settling on the surface in the current case was about 0.3–0.4 μm before the dust storm and about 0.5–0.7 μm during the dust storm. Particles that appeared in high concentration but were smaller than the critical size deposited onto the surface at a small number flux. The elements Al, Si and Mg were frequently detected in all samples, indicating the dominance of mineral particles. The frequency of Al in particles collected before the dust storm was significantly lower than for those collected during and after the dust storm. The frequencies of Cl and Fe did not show obvious changes, while those of S, K and Ca decreased after the dust arrival. These results indicate that the dust particles deposited onto the surface were less influenced by anthropogenic pollutants in terms of particle number.
