Based on back analysis of lateral displacements measured in situ by using the analytical solution, a useful method for estimating stress concentration ratio of geosynthetic-reinforced and pile-supported(GRPS) embankme...Based on back analysis of lateral displacements measured in situ by using the analytical solution, a useful method for estimating stress concentration ratio of geosynthetic-reinforced and pile-supported(GRPS) embankments was proposed. In order to validate the proposed method, a full-scale high-speed railway embankment(HSRE) with four instrumented subsections over medium compressibility silty clay was constructed in three stages. The soil profile, construction procedure and monitoring of settlements and lateral displacements of the four test sections were described. The field deformation analysis results show that 1) the combined reinforcement of CFG piles and geosynthetic layer perform well in terms of reducing lateral displacements; 2) the development of lateral displacements lags behind the increase of fill load, which can be attributed to the vertical load transfer mechanism of the pile foundation; and 3) pile length has a dominant effect on the stress distribution proportion between piles and surrounding soils. The comparison between predicted and experimental results suggests that the proposed analytical solution and the back analysis-based method are capable of reasonably estimating the lateral deformation and the stress concentration ratio, respectively, if the appropriate soil elastic modulus is chosen.展开更多
With titanium-bearing blast furnace slag, ammonium sulfate, citric acid and potassium carbonate as raw materials to produce foliar fertilizer and Ca-S-Si compound fertilizer by means of heating process for the first t...With titanium-bearing blast furnace slag, ammonium sulfate, citric acid and potassium carbonate as raw materials to produce foliar fertilizer and Ca-S-Si compound fertilizer by means of heating process for the first time, which improved the solubility of the slag and converted the nutritional elements into such ones which are prone to be absorbed by plants. The effects of process conditions on dissolution rate of titanium were mainly analyzed through the orthogonal experiment. The results showed that the optimum synthesis process conditions of foliar fertilizer from the slag were 360 ℃ for 35 min, the mass ratio of ammonium sulfate and titanium-bearing blast furnace slag was 8:1. Under these conditions more than 80% of iron, titanium, magnesium and part of silicon in titanium-bearing blast furnace slag converted into water-soluble substances and existing in foliar fertilizer. Foliar fertilizer contained nitrogen, sulfur, potassium, iron, titanium, magnesium and silicon, and pH value of foliar fertilizer was 6. Ca-S-Si compound fertilizer mainly contained calcium silicate and calcium sulfate, which existed in the form of citric acid-soluble substance and slightly soluble substance, respectively.展开更多
The interface and surface properties of nano-hydroxyapatite(n-HA) and poly( 1, 4-phenylene sulfide)-poly (2,4-phenylene sulfide acid)(PPS-PPSA) copolymer composite were investigated. The results show that there are so...The interface and surface properties of nano-hydroxyapatite(n-HA) and poly( 1, 4-phenylene sulfide)-poly (2,4-phenylene sulfide acid)(PPS-PPSA) copolymer composite were investigated. The results show that there are some strong interface combinations of calcium ion (Ca2+ ), car-boxyl (-COO- ) and phosphate radicle ion (PO_4~3- ) between copolymer and n-HA in the composite. The presence of the 2,4-phenylene sulfide acid in copolymer can increase the affinity to n-HA, which causes the formation of chemical bindings between the PPS-PPSA copolymer and n-HA. XRD analysis and IR surface analysis indicate that n-HA is not encapsulated by copolymer but exposed on the surface of the composite, and has same structure and properties with the origi-nal n-HA. The presence of the interface chemical bindings between the PPS-PPSA copolymer and n-HA can increase the content of n-HA in composite but does not cause the decrease of the composite mechanical strength.展开更多
MC3T3-E1 osteoblasts were cultured on H2O2- modified and unmodified carbon/carbon (H-C/C and C/C) composites for one week in order to evaluate differences in cell adhesion, spreading, and proliferation. The results ...MC3T3-E1 osteoblasts were cultured on H2O2- modified and unmodified carbon/carbon (H-C/C and C/C) composites for one week in order to evaluate differences in cell adhesion, spreading, and proliferation. The results indicated a certain degree of enhancement in the cell adhesion capability of osteoblasts cultured on H-C/C samples. Cellu- lar morphologies after cell adhesion were observed via scan- ning electron microscopy (SEM), which showed that the cells adhered more closely and spread more widely on the H-C/C sample surface. However, no cell appeared in several mul- tiple and continuous types of minor pores on both the C/C and H-C/C surfaces. In addition, two unique situations were observed on the H-C/C samples: an outline change of the osteoblasts was observed when the cells spread across some minor pores, and the cells entered and adhered well in some larger pores.展开更多
TiO2 nanoparticles have been synthesized by using a TiO2@NaCl core-shell structure as the precursor. The surface defects were well preserved by the NaCl shell, and therefore high oxygen adsorption capacity was observe...TiO2 nanoparticles have been synthesized by using a TiO2@NaCl core-shell structure as the precursor. The surface defects were well preserved by the NaCl shell, and therefore high oxygen adsorption capacity was observed. After the NaC1 shell was removed, the resulting pure TiO2 nanoparticles were of anatase phase and uniform size of around 20-24 nm. The presence of an abundance of surface defects contributes to the high photocatalytic activity of the synthesized materials, and the TiO: mate- rials obtained from the TiO2@NaCl precursor can be used as efficient photocatalysts for degradation of rhodamine B under UV light irradiation.展开更多
Cube-like Ag-Ag2MoO4 composite has been successfully prepared in the presence of PVP (potyvinylpyrrolidone) via a facile microwave-assisted hydrothermal process. Studies of its photocatalytic performance in the deco...Cube-like Ag-Ag2MoO4 composite has been successfully prepared in the presence of PVP (potyvinylpyrrolidone) via a facile microwave-assisted hydrothermal process. Studies of its photocatalytic performance in the decomposition of RhB indicate that the cube-like Ag-Ag2MoO4 composite exhibits good catalytic activities under visible-light irradiation. The face that Ag pro- motes the absorption of visible light may be attributed to the surface plasmon resonance. Further XRD characterization after recycle photocatalytic tests confirms that partial Ag~ ions in Ag2MoO4 have been reduced to metallic Ag. Reaction temperature, reaction time and the amount of PVP have also been studied and found to play crucial roles in the formation of the cube-like microstructures.展开更多
基金Project(2010G003-F)supported by Technological Research and Development Programs of the Ministry of Railways,China
文摘Based on back analysis of lateral displacements measured in situ by using the analytical solution, a useful method for estimating stress concentration ratio of geosynthetic-reinforced and pile-supported(GRPS) embankments was proposed. In order to validate the proposed method, a full-scale high-speed railway embankment(HSRE) with four instrumented subsections over medium compressibility silty clay was constructed in three stages. The soil profile, construction procedure and monitoring of settlements and lateral displacements of the four test sections were described. The field deformation analysis results show that 1) the combined reinforcement of CFG piles and geosynthetic layer perform well in terms of reducing lateral displacements; 2) the development of lateral displacements lags behind the increase of fill load, which can be attributed to the vertical load transfer mechanism of the pile foundation; and 3) pile length has a dominant effect on the stress distribution proportion between piles and surrounding soils. The comparison between predicted and experimental results suggests that the proposed analytical solution and the back analysis-based method are capable of reasonably estimating the lateral deformation and the stress concentration ratio, respectively, if the appropriate soil elastic modulus is chosen.
基金This study was supported by the National Natural Science Foundation of China (No. 50874029) and the National Basic Research Program of China (No.2007CB613504). Thanks are due to X.L. Nan and B.Y. Ma for their assistance in language editing.
文摘With titanium-bearing blast furnace slag, ammonium sulfate, citric acid and potassium carbonate as raw materials to produce foliar fertilizer and Ca-S-Si compound fertilizer by means of heating process for the first time, which improved the solubility of the slag and converted the nutritional elements into such ones which are prone to be absorbed by plants. The effects of process conditions on dissolution rate of titanium were mainly analyzed through the orthogonal experiment. The results showed that the optimum synthesis process conditions of foliar fertilizer from the slag were 360 ℃ for 35 min, the mass ratio of ammonium sulfate and titanium-bearing blast furnace slag was 8:1. Under these conditions more than 80% of iron, titanium, magnesium and part of silicon in titanium-bearing blast furnace slag converted into water-soluble substances and existing in foliar fertilizer. Foliar fertilizer contained nitrogen, sulfur, potassium, iron, titanium, magnesium and silicon, and pH value of foliar fertilizer was 6. Ca-S-Si compound fertilizer mainly contained calcium silicate and calcium sulfate, which existed in the form of citric acid-soluble substance and slightly soluble substance, respectively.
文摘The interface and surface properties of nano-hydroxyapatite(n-HA) and poly( 1, 4-phenylene sulfide)-poly (2,4-phenylene sulfide acid)(PPS-PPSA) copolymer composite were investigated. The results show that there are some strong interface combinations of calcium ion (Ca2+ ), car-boxyl (-COO- ) and phosphate radicle ion (PO_4~3- ) between copolymer and n-HA in the composite. The presence of the 2,4-phenylene sulfide acid in copolymer can increase the affinity to n-HA, which causes the formation of chemical bindings between the PPS-PPSA copolymer and n-HA. XRD analysis and IR surface analysis indicate that n-HA is not encapsulated by copolymer but exposed on the surface of the composite, and has same structure and properties with the origi-nal n-HA. The presence of the interface chemical bindings between the PPS-PPSA copolymer and n-HA can increase the content of n-HA in composite but does not cause the decrease of the composite mechanical strength.
基金supported by the National Natural Science Foundation of China(51472203 and 51521061)the Natural Science Basic Research Plan in Shaanxi Province of China(2014JM6233)"111" project of china(B08040)
文摘MC3T3-E1 osteoblasts were cultured on H2O2- modified and unmodified carbon/carbon (H-C/C and C/C) composites for one week in order to evaluate differences in cell adhesion, spreading, and proliferation. The results indicated a certain degree of enhancement in the cell adhesion capability of osteoblasts cultured on H-C/C samples. Cellu- lar morphologies after cell adhesion were observed via scan- ning electron microscopy (SEM), which showed that the cells adhered more closely and spread more widely on the H-C/C sample surface. However, no cell appeared in several mul- tiple and continuous types of minor pores on both the C/C and H-C/C surfaces. In addition, two unique situations were observed on the H-C/C samples: an outline change of the osteoblasts was observed when the cells spread across some minor pores, and the cells entered and adhered well in some larger pores.
基金supported by the Engineering and Technology Research Center of Food Preservation,Processing and Safety Control of Liaoning Province,Food Safety Key Lab of Liaoning Province (LNSAKF2011027)Key Laboratory Project of Department of Education of Liaoning Province (2009s004)
文摘TiO2 nanoparticles have been synthesized by using a TiO2@NaCl core-shell structure as the precursor. The surface defects were well preserved by the NaCl shell, and therefore high oxygen adsorption capacity was observed. After the NaC1 shell was removed, the resulting pure TiO2 nanoparticles were of anatase phase and uniform size of around 20-24 nm. The presence of an abundance of surface defects contributes to the high photocatalytic activity of the synthesized materials, and the TiO: mate- rials obtained from the TiO2@NaCl precursor can be used as efficient photocatalysts for degradation of rhodamine B under UV light irradiation.
基金supported by the National Basic Research Program of China (2013CB922102)the National Natural Science Foundation of China(21021062)the US National Science Foundation (CHE-1012173)
文摘Cube-like Ag-Ag2MoO4 composite has been successfully prepared in the presence of PVP (potyvinylpyrrolidone) via a facile microwave-assisted hydrothermal process. Studies of its photocatalytic performance in the decomposition of RhB indicate that the cube-like Ag-Ag2MoO4 composite exhibits good catalytic activities under visible-light irradiation. The face that Ag pro- motes the absorption of visible light may be attributed to the surface plasmon resonance. Further XRD characterization after recycle photocatalytic tests confirms that partial Ag~ ions in Ag2MoO4 have been reduced to metallic Ag. Reaction temperature, reaction time and the amount of PVP have also been studied and found to play crucial roles in the formation of the cube-like microstructures.