Carbon fiber-reinforced carbon aerogel(C/CA)composites are one of the most promising candidates for applications requiring both thermal insulation and load bearing capabilities.The preparation of anti-oxidation coatin...Carbon fiber-reinforced carbon aerogel(C/CA)composites are one of the most promising candidates for applications requiring both thermal insulation and load bearing capabilities.The preparation of anti-oxidation coatings on C/CA to address its susceptibility to oxidation is a feasible approach to promote its application in oxidative environments.However,the currently reported coatings on C/CA mainly focus on improving the ablation performance and coating preparation process typically necessitating high-temperature heat treatment.This procedure can increase its thermal conductivity and reduce its thermal insulation ability.In this study,a series of ceramic-resin coatings were fabricated on C/CA through a simple slurry brushing-drying approach at room temperature.The effects of phenolic resin content on the coating structure,residual stress,thermal shock,and oxidation behaviors were investigated.Due to the adhesive properties and curing-induced shrinkage,the PR-7.5 coating(containing 7.5%(in mass)phenolic resin in the slurry)exhibits bonding strength close to fracture strength of the substrate and residual compressive stress of 0.853 GPa,which is beneficial for resisting thermal shock cracking.However,excessive resin content(PR-10.0 containing 10.0%(in mass)phenolic resin in the slurry)induces tensile stress due to uneven curing shrinkage,thereby leading to thermal shock cracking.Meanwhile,oxidation tests reveal significantly reduced weight losses for PR-7.5(17.46%at 800℃/100 min,8.15%at 1000℃/120 min,3.15%at 1200℃/120 min)versus uncoated C/CA’s 44.60%loss at 800℃/20 min.This work provides a brand-new and simple approach to improving the anti-oxidation performance of C/CA and expands its application in mild oxidative environments.展开更多
Ca3Co409/polyaniline bulk composites have been successfully fabricated by ball-milling and hot-pressing method. Our results indicate that the Seebeck coefficient can be increased nearly by 400% with adding 15 wt% 0a3C...Ca3Co409/polyaniline bulk composites have been successfully fabricated by ball-milling and hot-pressing method. Our results indicate that the Seebeck coefficient can be increased nearly by 400% with adding 15 wt% 0a3Co409 to the polyaniline. The thermal conductivity changes slightly with increasing filler content. The highest figure of merit, ZT can reach 5× 10-4 at 329 K for these bulk composites, which is almost 50 times larger than that of pure polyaniline, suggesting that the polymer-thermoelectric oxide composites are promising candidates for light-weight, low-cost and non-toxic thermoelectric applications.展开更多
For this study, an intercalation compounding method was used to prepare Chinese fir wood/Ca-montmorillonite （Ca-MMT） composite board to improve its properties such as surface mechanical properties, flame retardance ...For this study, an intercalation compounding method was used to prepare Chinese fir wood/Ca-montmorillonite （Ca-MMT） composite board to improve its properties such as surface mechanical properties, flame retardance and dimensional stability. By virtue of water-soluble phenolic resin （PF）, Chinese fir wood and Ca-MMT were mixed by pressure and vacuum impregnation. The optimum impregnation technology of Chinese fir wood/Ca-MMT composite board was obtained by using an orthogonal design and a single factor design of pressure and vacuum impregnation, using weight percent gain （WPG） as the basic index. The results are as follows： 1） On the basis of the orthogonal design and an actual experiment, the optimum preparation technology of Chinese fir wood/Ca-MMT composite board is 20% PF resin dispersion concentration （wt%）, 1.0 CEC amount of organic intercalation agent, 0.098 MPa vacuum degree, 5% concentration of Ca-MMT and 1.0 MPa pressure. 2） The WPG of the composite board samples of 450 mm length was much larger than that of the samples of 600, 750 and 900 mm length. Warm water extraction contributed little to WPG展开更多
Several gelatin-silicate composites, with or without incorporation of Ca2+ ions, were synthesized through sol-gel processing starting from gelatin and 3- (glycidoxypropyl) trimethoxysilane. The structure around the Si...Several gelatin-silicate composites, with or without incorporation of Ca2+ ions, were synthesized through sol-gel processing starting from gelatin and 3- (glycidoxypropyl) trimethoxysilane. The structure around the Si atoms was similar for all the samples. The measurement of viscoelastic properties indicated that the glass transition temperature and activation energy decreased with the incorporation of Ca2+ ions. The Ca2+ ion-containing composites were bioactive as they spontaneously deposited apatite when soaked in a simulated body fluid of the Kokubo recipe.展开更多
Objective To evaluate the biomechanics of hollow-compression-screw in the osteoporotic femoral neck with composite c alcium phosphate cement (CCPC).Methods Sixteen femurs of superior segment were randomly divided into...Objective To evaluate the biomechanics of hollow-compression-screw in the osteoporotic femoral neck with composite c alcium phosphate cement (CCPC).Methods Sixteen femurs of superior segment were randomly divided into two groups:augmentation group and non-augmentation group.CCPC was used in augmentation group.Result Augmentation with CCPC would improve the initial mobile force of hollow-compression-screw,the ini tial mobile force and the maximal axial pull-out strength for augmentation group,non-augmentation group in-creased from(192.7±14.0)N and(202.8±14.0)N to(328.5±34.7)N and(347.8±31.2)N.There was significant difference of two groups(P <0.01).Conclusion CCPC can enhance hollow-compressio n-screw fixation in osteoporotic fe moral neck.展开更多
Rice(Oryza sativa L.)is a globally important food crop.Its bran oil has high nutritional value,but with a low content of oleic acid and a high content of linoleic acid,which affects the stability and shelf life of the...Rice(Oryza sativa L.)is a globally important food crop.Its bran oil has high nutritional value,but with a low content of oleic acid and a high content of linoleic acid,which affects the stability and shelf life of the oil(Warner et al.2008;Liang et al.2017;Doureradjou and Koner 2020;Ghasemzadeh et al.2020).The fatty acid composition of rice bran oil is one of the healthiest edible oils due to its balanced source of saturated,monounsaturated,and polyunsaturated fatty acids with a ratio of 0.6:1.1:1(Liang et al.2017;Awad et al.2022).展开更多
基金National Natural Science Foundation of China(52272075,52472053)Research Fund of Youth Innovation Promotion Association of CAS,China(2021190)Defense Industrial Technology Development Program(JCKY2021130B007)。
文摘Carbon fiber-reinforced carbon aerogel(C/CA)composites are one of the most promising candidates for applications requiring both thermal insulation and load bearing capabilities.The preparation of anti-oxidation coatings on C/CA to address its susceptibility to oxidation is a feasible approach to promote its application in oxidative environments.However,the currently reported coatings on C/CA mainly focus on improving the ablation performance and coating preparation process typically necessitating high-temperature heat treatment.This procedure can increase its thermal conductivity and reduce its thermal insulation ability.In this study,a series of ceramic-resin coatings were fabricated on C/CA through a simple slurry brushing-drying approach at room temperature.The effects of phenolic resin content on the coating structure,residual stress,thermal shock,and oxidation behaviors were investigated.Due to the adhesive properties and curing-induced shrinkage,the PR-7.5 coating(containing 7.5%(in mass)phenolic resin in the slurry)exhibits bonding strength close to fracture strength of the substrate and residual compressive stress of 0.853 GPa,which is beneficial for resisting thermal shock cracking.However,excessive resin content(PR-10.0 containing 10.0%(in mass)phenolic resin in the slurry)induces tensile stress due to uneven curing shrinkage,thereby leading to thermal shock cracking.Meanwhile,oxidation tests reveal significantly reduced weight losses for PR-7.5(17.46%at 800℃/100 min,8.15%at 1000℃/120 min,3.15%at 1200℃/120 min)versus uncoated C/CA’s 44.60%loss at 800℃/20 min.This work provides a brand-new and simple approach to improving the anti-oxidation performance of C/CA and expands its application in mild oxidative environments.
基金supported by the National Basic Research Program of China("973 Program",No.2013CB632506)the National Natural Science Foundation of China(No.51025205)the Specialized Research Fund for the Doctoral Program of Higher Education(No.20120002110006)
文摘Ca3Co409/polyaniline bulk composites have been successfully fabricated by ball-milling and hot-pressing method. Our results indicate that the Seebeck coefficient can be increased nearly by 400% with adding 15 wt% 0a3Co409 to the polyaniline. The thermal conductivity changes slightly with increasing filler content. The highest figure of merit, ZT can reach 5× 10-4 at 329 K for these bulk composites, which is almost 50 times larger than that of pure polyaniline, suggesting that the polymer-thermoelectric oxide composites are promising candidates for light-weight, low-cost and non-toxic thermoelectric applications.
基金the National Natural Science Foundation of China (Grant No.30271055)
文摘For this study, an intercalation compounding method was used to prepare Chinese fir wood/Ca-montmorillonite （Ca-MMT） composite board to improve its properties such as surface mechanical properties, flame retardance and dimensional stability. By virtue of water-soluble phenolic resin （PF）, Chinese fir wood and Ca-MMT were mixed by pressure and vacuum impregnation. The optimum impregnation technology of Chinese fir wood/Ca-MMT composite board was obtained by using an orthogonal design and a single factor design of pressure and vacuum impregnation, using weight percent gain （WPG） as the basic index. The results are as follows： 1） On the basis of the orthogonal design and an actual experiment, the optimum preparation technology of Chinese fir wood/Ca-MMT composite board is 20% PF resin dispersion concentration （wt%）, 1.0 CEC amount of organic intercalation agent, 0.098 MPa vacuum degree, 5% concentration of Ca-MMT and 1.0 MPa pressure. 2） The WPG of the composite board samples of 450 mm length was much larger than that of the samples of 600, 750 and 900 mm length. Warm water extraction contributed little to WPG
文摘Several gelatin-silicate composites, with or without incorporation of Ca2+ ions, were synthesized through sol-gel processing starting from gelatin and 3- (glycidoxypropyl) trimethoxysilane. The structure around the Si atoms was similar for all the samples. The measurement of viscoelastic properties indicated that the glass transition temperature and activation energy decreased with the incorporation of Ca2+ ions. The Ca2+ ion-containing composites were bioactive as they spontaneously deposited apatite when soaked in a simulated body fluid of the Kokubo recipe.
文摘Objective To evaluate the biomechanics of hollow-compression-screw in the osteoporotic femoral neck with composite c alcium phosphate cement (CCPC).Methods Sixteen femurs of superior segment were randomly divided into two groups:augmentation group and non-augmentation group.CCPC was used in augmentation group.Result Augmentation with CCPC would improve the initial mobile force of hollow-compression-screw,the ini tial mobile force and the maximal axial pull-out strength for augmentation group,non-augmentation group in-creased from(192.7±14.0)N and(202.8±14.0)N to(328.5±34.7)N and(347.8±31.2)N.There was significant difference of two groups(P <0.01).Conclusion CCPC can enhance hollow-compressio n-screw fixation in osteoporotic fe moral neck.
基金supported by the National Natural Science Foundation of China(32201861)Ministry of Agriculture and Rural Affairs of China,the Key Research and Development Program of Jiangsu Province,China(BE2022383)the Zhongshan Biological Breeding Laboratory,China(ZSBBLKY2023-04-1)。
文摘Rice(Oryza sativa L.)is a globally important food crop.Its bran oil has high nutritional value,but with a low content of oleic acid and a high content of linoleic acid,which affects the stability and shelf life of the oil(Warner et al.2008;Liang et al.2017;Doureradjou and Koner 2020;Ghasemzadeh et al.2020).The fatty acid composition of rice bran oil is one of the healthiest edible oils due to its balanced source of saturated,monounsaturated,and polyunsaturated fatty acids with a ratio of 0.6:1.1:1(Liang et al.2017;Awad et al.2022).
