Viscose fiber templates(15 cm×15 cm×1 cm)were put into ZrOCl_(2) solutions of different concentrations(1,2 and 3 mol·L^(-1))and impregnated at different temperatures(20,40 and 60℃)for 20 h.After washin...Viscose fiber templates(15 cm×15 cm×1 cm)were put into ZrOCl_(2) solutions of different concentrations(1,2 and 3 mol·L^(-1))and impregnated at different temperatures(20,40 and 60℃)for 20 h.After washing,centrifugation and drying,ZrO_(2) fiber precursors were obtained.ZrO_(2) fibers were prepared by heat treatment of the precursors at different temperatures(600,800,1000 and 1200℃)for 2 h.The effects of the impregnation temperature,the impregnation solution concentration and the heat treatment temperature on the microstructure and the phase composition of the ZrO_(2) fibers were studied.The results show that with the increase of the impregnation temperature from 20℃to 60℃and the impregnation solution concentration increase from 1 mol·L^(-1) to 3 mol·L^(-1),the microstructure of fiber cross section changes from flat to cylindrical,and the average fiber diameter increases,indicating that the increase of the impregnation solution concentration and the impregnation temperature is beneficial to increasing the adsorption capacity of Zr4+on viscose fiber templates.After heat treatment,ZrO_(2) fiber mainly exists in the form of monoclinic ZrO_(2).With the increase of the heat treatment temperature,the grains in ZrO_(2) fibers become larger and the crystallinity degree increases,meanwhile the fiber surface undergoes a transition from smooth to small grains and then to cracks.展开更多
High-pressure impregnation, a new preparation method for sorbents to remove H2S from hot coal gas, is introduced in this paper. Semi-coke （SC） and ZnO is selected as the support and active component of sorbent, resp...High-pressure impregnation, a new preparation method for sorbents to remove H2S from hot coal gas, is introduced in this paper. Semi-coke （SC） and ZnO is selected as the support and active component of sorbent, respectively. The sorbent preparation process includes high-pressure impregnation, filtration, ovendry and calcination. The aim of this research is to primarily study the effects of the impregnation pressure on physical properties and desulfurization ability of the sorbent. The desulfurization experiment was carried out in a fixed-bed reactor at 500 ~C and a simulated coal gas used in this work was composed of CO （33 vol%）, H2 （39 vol%）, H2S （300 ppm in volume）, and N2 （balance）. Experimental results show that the pore structure of the SC support can be improved effectively and ZnO active component can be uniformly dispersed on the support, with the small particle size of 10-500 nm. Sorbents prepared using high-pressure impregnation have better desulfurization capacity and their active components have higher utilization rate. P20-ZnSC sorbent, obtained by high-pressure impregnation at 20 atm, has the best desulfurization ability with a sulfur capacity of 7.54 g S/100g sorbent and a breakthrough time of 44 h. Its desulfurization precision and efficiency of removing H2S from the middle temperature gases can reach 〈 1 ppm and 〉99.7%, respectively, before sorbent breakthrough.展开更多
In this paper, we deals with mechanical performance of resin impregnation with natural fiber and fiber reinforced composites. The effect of the addition of a rein impregnation process on static strength of the injecti...In this paper, we deals with mechanical performance of resin impregnation with natural fiber and fiber reinforced composites. The effect of the addition of a rein impregnation process on static strength of the injection molded composites was investigated by carrying out tensile and banding tests, followed by Scanning electron microscopy (SEM) observation of fiber surface and fracture surface of composites. The tensile strength of natural fiber and natural fiber reinforced composites with resin impregnation method increases with Polyvinyl alcohol (PVA) impregnation. In addition, Phenol resin impregnation recovers fiber tensile strength after alkali treatment. Resin impregnation causes decrease in contact surface area;however, it does not cause decrease in mechanical properties. Our results suggest that the using rein impregnation method has better effect on the mechanical properties of natural fiber reinforced Polypropylene (PP) composites.展开更多
Sodium silicate modification can improve the overall performance of wood.The modification process has a great influence on the properties of modified wood.In this study,a new method was introduced to analyze the wood ...Sodium silicate modification can improve the overall performance of wood.The modification process has a great influence on the properties of modified wood.In this study,a new method was introduced to analyze the wood modification process,and the properties of modified wood were studied.Poplar wood was modified with sodium silicate by vacuum-pressure impregnation.After screening using single-factor experiments,an orthogonal experiment was carried out with solution concentration,impregnation time,impregnation pressure,and the cycle times as experimental factors.The modified poplar with the best properties was selected by fuzzy mathematics and characterized by SEM,FT-IR,XRD and TG.The results showed that some lignin and hemicellulose were removed from the wood due to the alkaline action of sodium silicate,and the orderly crystal area of poplar became disorderly,resulting in the reduction of crystallinity of the modified poplar wood.FT-IR analysis showed that sodium silicate was hydrolyzed to form polysilicic acid in wood,and structural analysis revealed the formation of Si-O-Si and Si-O-C,indicating that sodium silicate reacted with fibers on the wood cell wall.TG-DTG curves showed that the final residual mass of modified poplar wood increased from 25%to 67%,and the temperature of the maximum loss rate decreased from 343℃ to 276℃.The heat release and smoke release of modified poplar wood decreased obviously.This kind of material with high strength and fire resistance can be used in the outdoor building and indoor furniture.展开更多
The steam-thermal method for refinery of highly-viscous oils and the process of propane-butane liquid extraction have been implemented for production of the impregnation material for carbon rock. The process of steam-...The steam-thermal method for refinery of highly-viscous oils and the process of propane-butane liquid extraction have been implemented for production of the impregnation material for carbon rock. The process of steam-thermal treatment has been carried out for highly-viscous oil from Ashalchinskoye accumulation with the “steam-oil” ratio changing from 1.1:1 to 1.4:1. The extraction process has been carried out at temperature T = 85°C and pressures from 4.5 to 8 MPa. Water absorption of carbonate rock has decreased to 0.34% as a result of SCF-impregnation process.展开更多
A 20 wt% Ni/bentonite catalyst was prepared by a solution combustion synthesis (SCS), which exhibited higher activity for the CO_2methanation than that of an impregnation method (IPM), and the catalyst prepared by SCS...A 20 wt% Ni/bentonite catalyst was prepared by a solution combustion synthesis (SCS), which exhibited higher activity for the CO_2methanation than that of an impregnation method (IPM), and the catalyst prepared by SCS showed a CO_2 conversion of 85% and a CH4selectivity of 100% at 300 °C, atmospheric pressure, and 3600 ml·(g cat)-1·h-1, and the catalyst exhibited stable within a 110-h reaction. The results showed higher me- tallic Ni dispersion, smaller Ni particle size, larger specific surface area and lower reduction temperature in the Ni/ bentonite prepared by SCS than that of IPM. And the Ni/bentonite prepared by the SCS moderated the interaction between NiO and bentonite.展开更多
Different types of carbon-silica fillers were prepared via pyrolysis-cum-water vapor of waste green tires tread and impregnation method. Dual phase fillers have been characterized by energy dispersive X-ray (EDX) spec...Different types of carbon-silica fillers were prepared via pyrolysis-cum-water vapor of waste green tires tread and impregnation method. Dual phase fillers have been characterized by energy dispersive X-ray (EDX) spectroscopy in a scanning transmission electron microscope (STEM) or STEM-EDX. Phase distribution in hybrid fillers for rubber was investigated. The results achieved show that the conditions of obtaining influence the distribution and the location of the phases in the carbon-silica hybrid fillers as well as their most essential characteristics including specific area, oil absorption number, iodine adsorption number, ash content and others.展开更多
Previously, Polyvinyl Alcohol (PVA) and phenolic resin were used for resin impregnated bamboo fiber reinforced PP composites which was manufactures for resin impregnated bamboo fiber with polypropylene (PP). Resin imp...Previously, Polyvinyl Alcohol (PVA) and phenolic resin were used for resin impregnated bamboo fiber reinforced PP composites which was manufactures for resin impregnated bamboo fiber with polypropylene (PP). Resin impregnation method can show improvement on tensile strength of fiber. However, to reduce the contact surface area and low inter-facial shear strength (IFSS) between impregnated resin and matrix, using 40% weight fraction of bamboo fiber in PP matrix, PVA impregnated composites with mean flexural and tensile strength 10% higher than untreated composites were produced butphenolic resin impregnated fiber reinforced composition’s mechanical properties were decreased. In this study maleic anhydride grafted polypropylene (MAPP) was used to increase interfacial shear strength between resin impregnated fiber and PP. With 10% MAPP, IFSS between resin impregnated fiber and PP increased more than 100% and reinforced composites. MAPP with untreated, phenolic resin and PVA impregnated cases showed similar mechanical properties. Yet in water absorption test, the PVA treatment with bamboo/PP composites increased water absorption ratio. But with 10% MAPP, matrix PP water absorption ratio decreased like phenolic resin impregnated fiber reinforced composites. 10% MAPP with resin impregnated bamboo fiber reinforced PP composites can improve IFSS, mechanical properties of composite and can decrease water absorption PVA resin impregnated bamboo fiber reinforced composites.展开更多
We use wavelet transform to analyze the daily relative sunspot number series over solar cycles 10-23. The characteristics of some of the periods shorter than - 600-day are discussed. The results exhibit not only the v...We use wavelet transform to analyze the daily relative sunspot number series over solar cycles 10-23. The characteristics of some of the periods shorter than - 600-day are discussed. The results exhibit not only the variation of some short periods in the 14 solar cycles but also the characteristics and differences around solar peaks and valley years. The short periodic components with larger amplitude such as ～27, ～ 150 and ～360-day are obvious in some solar cycles, all of them are time-variable, also their lengths and amplitudes are variable and intermittent in time. The variable characteristics of the periods are rather different in different solar cycles.展开更多
文摘Viscose fiber templates(15 cm×15 cm×1 cm)were put into ZrOCl_(2) solutions of different concentrations(1,2 and 3 mol·L^(-1))and impregnated at different temperatures(20,40 and 60℃)for 20 h.After washing,centrifugation and drying,ZrO_(2) fiber precursors were obtained.ZrO_(2) fibers were prepared by heat treatment of the precursors at different temperatures(600,800,1000 and 1200℃)for 2 h.The effects of the impregnation temperature,the impregnation solution concentration and the heat treatment temperature on the microstructure and the phase composition of the ZrO_(2) fibers were studied.The results show that with the increase of the impregnation temperature from 20℃to 60℃and the impregnation solution concentration increase from 1 mol·L^(-1) to 3 mol·L^(-1),the microstructure of fiber cross section changes from flat to cylindrical,and the average fiber diameter increases,indicating that the increase of the impregnation solution concentration and the impregnation temperature is beneficial to increasing the adsorption capacity of Zr4+on viscose fiber templates.After heat treatment,ZrO_(2) fiber mainly exists in the form of monoclinic ZrO_(2).With the increase of the heat treatment temperature,the grains in ZrO_(2) fibers become larger and the crystallinity degree increases,meanwhile the fiber surface undergoes a transition from smooth to small grains and then to cracks.
基金supported by the financial support of National Basic Research Program of China (2012CB723105)National Natural Science Foundation of China (20976117)+1 种基金Shanxi Province Natural Science Foundation(2010011014-3)Shanxi Province Basic Conditions Platform for Science and Technology Project (2010091015)
文摘High-pressure impregnation, a new preparation method for sorbents to remove H2S from hot coal gas, is introduced in this paper. Semi-coke （SC） and ZnO is selected as the support and active component of sorbent, respectively. The sorbent preparation process includes high-pressure impregnation, filtration, ovendry and calcination. The aim of this research is to primarily study the effects of the impregnation pressure on physical properties and desulfurization ability of the sorbent. The desulfurization experiment was carried out in a fixed-bed reactor at 500 ~C and a simulated coal gas used in this work was composed of CO （33 vol%）, H2 （39 vol%）, H2S （300 ppm in volume）, and N2 （balance）. Experimental results show that the pore structure of the SC support can be improved effectively and ZnO active component can be uniformly dispersed on the support, with the small particle size of 10-500 nm. Sorbents prepared using high-pressure impregnation have better desulfurization capacity and their active components have higher utilization rate. P20-ZnSC sorbent, obtained by high-pressure impregnation at 20 atm, has the best desulfurization ability with a sulfur capacity of 7.54 g S/100g sorbent and a breakthrough time of 44 h. Its desulfurization precision and efficiency of removing H2S from the middle temperature gases can reach 〈 1 ppm and 〉99.7%, respectively, before sorbent breakthrough.
文摘In this paper, we deals with mechanical performance of resin impregnation with natural fiber and fiber reinforced composites. The effect of the addition of a rein impregnation process on static strength of the injection molded composites was investigated by carrying out tensile and banding tests, followed by Scanning electron microscopy (SEM) observation of fiber surface and fracture surface of composites. The tensile strength of natural fiber and natural fiber reinforced composites with resin impregnation method increases with Polyvinyl alcohol (PVA) impregnation. In addition, Phenol resin impregnation recovers fiber tensile strength after alkali treatment. Resin impregnation causes decrease in contact surface area;however, it does not cause decrease in mechanical properties. Our results suggest that the using rein impregnation method has better effect on the mechanical properties of natural fiber reinforced Polypropylene (PP) composites.
基金This work was financially supported by National Natural Science Foundation of China(32201485)Natural Science Foundation of Hunan Province,China(2022JJ40863)+1 种基金Scientific Research Project of Hunan Provincial Education Department,China(21B0238)The Science and Technology Innovation Program of Hunan Province(2021RC4062).
文摘Sodium silicate modification can improve the overall performance of wood.The modification process has a great influence on the properties of modified wood.In this study,a new method was introduced to analyze the wood modification process,and the properties of modified wood were studied.Poplar wood was modified with sodium silicate by vacuum-pressure impregnation.After screening using single-factor experiments,an orthogonal experiment was carried out with solution concentration,impregnation time,impregnation pressure,and the cycle times as experimental factors.The modified poplar with the best properties was selected by fuzzy mathematics and characterized by SEM,FT-IR,XRD and TG.The results showed that some lignin and hemicellulose were removed from the wood due to the alkaline action of sodium silicate,and the orderly crystal area of poplar became disorderly,resulting in the reduction of crystallinity of the modified poplar wood.FT-IR analysis showed that sodium silicate was hydrolyzed to form polysilicic acid in wood,and structural analysis revealed the formation of Si-O-Si and Si-O-C,indicating that sodium silicate reacted with fibers on the wood cell wall.TG-DTG curves showed that the final residual mass of modified poplar wood increased from 25%to 67%,and the temperature of the maximum loss rate decreased from 343℃ to 276℃.The heat release and smoke release of modified poplar wood decreased obviously.This kind of material with high strength and fire resistance can be used in the outdoor building and indoor furniture.
文摘The steam-thermal method for refinery of highly-viscous oils and the process of propane-butane liquid extraction have been implemented for production of the impregnation material for carbon rock. The process of steam-thermal treatment has been carried out for highly-viscous oil from Ashalchinskoye accumulation with the “steam-oil” ratio changing from 1.1:1 to 1.4:1. The extraction process has been carried out at temperature T = 85°C and pressures from 4.5 to 8 MPa. Water absorption of carbonate rock has decreased to 0.34% as a result of SCF-impregnation process.
基金Supported by the National Natural Science Foundation of China(21566005)the Natural Science Foundation of Guangxi Province(2016GXNSFFA380015)
文摘A 20 wt% Ni/bentonite catalyst was prepared by a solution combustion synthesis (SCS), which exhibited higher activity for the CO_2methanation than that of an impregnation method (IPM), and the catalyst prepared by SCS showed a CO_2 conversion of 85% and a CH4selectivity of 100% at 300 °C, atmospheric pressure, and 3600 ml·(g cat)-1·h-1, and the catalyst exhibited stable within a 110-h reaction. The results showed higher me- tallic Ni dispersion, smaller Ni particle size, larger specific surface area and lower reduction temperature in the Ni/ bentonite prepared by SCS than that of IPM. And the Ni/bentonite prepared by the SCS moderated the interaction between NiO and bentonite.
文摘Different types of carbon-silica fillers were prepared via pyrolysis-cum-water vapor of waste green tires tread and impregnation method. Dual phase fillers have been characterized by energy dispersive X-ray (EDX) spectroscopy in a scanning transmission electron microscope (STEM) or STEM-EDX. Phase distribution in hybrid fillers for rubber was investigated. The results achieved show that the conditions of obtaining influence the distribution and the location of the phases in the carbon-silica hybrid fillers as well as their most essential characteristics including specific area, oil absorption number, iodine adsorption number, ash content and others.
文摘Previously, Polyvinyl Alcohol (PVA) and phenolic resin were used for resin impregnated bamboo fiber reinforced PP composites which was manufactures for resin impregnated bamboo fiber with polypropylene (PP). Resin impregnation method can show improvement on tensile strength of fiber. However, to reduce the contact surface area and low inter-facial shear strength (IFSS) between impregnated resin and matrix, using 40% weight fraction of bamboo fiber in PP matrix, PVA impregnated composites with mean flexural and tensile strength 10% higher than untreated composites were produced butphenolic resin impregnated fiber reinforced composition’s mechanical properties were decreased. In this study maleic anhydride grafted polypropylene (MAPP) was used to increase interfacial shear strength between resin impregnated fiber and PP. With 10% MAPP, IFSS between resin impregnated fiber and PP increased more than 100% and reinforced composites. MAPP with untreated, phenolic resin and PVA impregnated cases showed similar mechanical properties. Yet in water absorption test, the PVA treatment with bamboo/PP composites increased water absorption ratio. But with 10% MAPP, matrix PP water absorption ratio decreased like phenolic resin impregnated fiber reinforced composites. 10% MAPP with resin impregnated bamboo fiber reinforced PP composites can improve IFSS, mechanical properties of composite and can decrease water absorption PVA resin impregnated bamboo fiber reinforced composites.
基金Supported by the National Natural Science Foundation of China.
文摘We use wavelet transform to analyze the daily relative sunspot number series over solar cycles 10-23. The characteristics of some of the periods shorter than - 600-day are discussed. The results exhibit not only the variation of some short periods in the 14 solar cycles but also the characteristics and differences around solar peaks and valley years. The short periodic components with larger amplitude such as ～27, ～ 150 and ～360-day are obvious in some solar cycles, all of them are time-variable, also their lengths and amplitudes are variable and intermittent in time. The variable characteristics of the periods are rather different in different solar cycles.
