[Objective] The aim was to explore release characteristics of vinyl chlo- ride-vinyl acetate copolymer controlled-release N fertilizer and the effects on minerat nitrogen in soils. [Method] Vinyl chloride-vinyl acetat...[Objective] The aim was to explore release characteristics of vinyl chlo- ride-vinyl acetate copolymer controlled-release N fertilizer and the effects on minerat nitrogen in soils. [Method] Vinyl chloride-vinyl acetate copolymer and hydroxyl-modi- fied VCNAc were taken as coating materials to prepare slow release fertilizer. Nutri- ent release characteristics of VC/VAc slow release fertilizer was evaluated by water immersion method and the effects of VC/VAc slow release fertilizer on mineral ni- trogen were researched by pot experiment. [Result] The release periods of VC-VAc controlled-release urea and hydroxyl-modified VC/VAc coated urea were 60 and 50 d, respectively. Furthermore, the content of ammonium nitrogen reached the peak on the 30th d and the content of nitrate nitrogen reached the peak on the 60th d in soils in treatments with VCNAc and hydroxyl-modified VC/VAc; the content of nitrate nitrogen rose again on the 120th d in the treatment with VC/VAc. In terms of wheat yield, different treatments showed insignificant differences and rice yield in the treatment with VCNAc was significantly higher than that in the treatment with hy- droxyl-modified VCNAc （P〈0.05）. [Conclusion] The release days of slow controlled- release fertilizer vary upon pot experiment method and water immersion method. Slow controlled-release fertilizer is not suitable for monoculture, due to long fertilizer efficiency, but multiple cropping would be optimal for its role to be fully exploited.展开更多
The discarded feathers / ethylene vinyl acetate copolymer( EVA) thermoplastic composite materials was obtained with discarded feathers as reinforced material and EVA powders as matrix material by hot pressing method. ...The discarded feathers / ethylene vinyl acetate copolymer( EVA) thermoplastic composite materials was obtained with discarded feathers as reinforced material and EVA powders as matrix material by hot pressing method. Sound absorption properties were studied by changing mass ratio of discarded feathers and EVA,thickness of composite materials,hot pressing pressure and hot pressing temperature. It was found that the sound absorption properties of composite materials were good when the mass ratio of discarded feathers and EVA was 1: 1,thickness of composite materials was 30 mm,hot pressing pressure was 8 MPa,and hot pressing temperature was 80 ℃. Under the optimum conditions,the effect of composite density on sound absorption property was analyzed. In a certain range,the sound absorption property was enhanced with the decrease of the composite density.When the composite density was 0. 1g /cm^3, the maximum absorption coefficient was 0.96. Finally,the capillary theory was used to calculate the maximum sound absorption coefficient of discarded feathers / EVA thermoplastic composite materials. The good agreements of experimental results and calculated results proved the validity of the theoretical models.展开更多
Bright blue polymer light-emitting diodes have been fabricated by using the poly(pphenylenevinylene)-based copolymers with 10 C long aliphatic chains as the electroluminescent layers,PBD in PMMA and Alq_(3) as the ele...Bright blue polymer light-emitting diodes have been fabricated by using the poly(pphenylenevinylene)-based copolymers with 10 C long aliphatic chains as the electroluminescent layers,PBD in PMMA and Alq_(3) as the electron-transporting layers,and aluminum as the cathode.The multilayer structure devices show 190cd/m^(2) light-emitting brightness at 460nm,15 V turn-on vol-tage.It is found that the intensities of photoluminescence and electroluminescence(EL)increase with increasing aliphatic chain length,the EL intensity and operation stability of these polymer light-emitting diodes can be improved by reasonable design of the structure.展开更多
Sepiolite （S9, B10, B20, B40） and boehmite have been added to an intumecent flame retardant （IFR） system to produce the halogen-free and fire-resistant ethylene-vinyl acetate copolymer （EVM） rubber. The rubber c...Sepiolite （S9, B10, B20, B40） and boehmite have been added to an intumecent flame retardant （IFR） system to produce the halogen-free and fire-resistant ethylene-vinyl acetate copolymer （EVM） rubber. The rubber contains ammonium polyphosphate （APP） as acid source, double pentaerythritol （D-PER） as carbon source and melamine （MN） as gas source. The effects of nano-filler sepiolite and boehmite on the fire-resistant property of EVM rubber based on IFR system were investigated. The test results show that the system with nano-filler of sepiolite B10 has the best fire-resistant property. The process of smoke emission and thermal decomposition, the element composition of char surface and the micro morphology of intumecent char layer of the EVM IFR system with nano-filler were also studied by NBS chamber, thermogravimetric （TG） analysis, X- ray photoelectron spectroscopy （XPS） and scanning electron microscope （SEM）.展开更多
Copolymer of maleic acid and acrylic acid （PMA-100）, combining with polyvinyl butyral （PVB） ultrafiltration membrane was used for the removal of Mn（II） from waste water by complexation-ultrafiltration. The carbo...Copolymer of maleic acid and acrylic acid （PMA-100）, combining with polyvinyl butyral （PVB） ultrafiltration membrane was used for the removal of Mn（II） from waste water by complexation-ultrafiltration. The carboxylic group content of PMA-100 and the rate of complexation reaction were measured. Effects of the mass ratio of PMA-100 to Mn（II） （n）, pH, background electrolyte, etc on the rejection rate （R） and permeate flux （J） were investigated. The results show that carboxylic group content of PMA-100 is 9.5 mmol/g. The complexation of Mn（II） with PMA-100 is rapid and completed within 5 min at pH 6.0. Both R and J increase with pH increasing in the range of 2.5-7.0, and R increases with the increase of n at pH 6.0 while J is little affected. The background electrolyte leads to the decrease of R, and CaCl2 has much greater effect on R than NaCl at the same ionic strength.展开更多
Poly （ethyleneglycol monomethylether） methacrylate （PEGMM）was synthesized by means of the reaction of methacrylyl chloride with sodium monomethylpolyethyleneglycoxide and was characterized by FTIR,;H-NMR,and ultra...Poly （ethyleneglycol monomethylether） methacrylate （PEGMM）was synthesized by means of the reaction of methacrylyl chloride with sodium monomethylpolyethyleneglycoxide and was characterized by FTIR,;H-NMR,and ultraviolet spectrometries. A series of poly （vinyl alcohol）-graft-PEGMM （PVA-g-PEGMM ）and methyl methacrylate-PEGMM copolymer （PMMA-PEGMM） were prepared and tested for antithrombogenicity in vitro. The results indicate that the antithrombogenicity of the copolymers basically increases with the increasing of the DP of polyoxyethylene （POE） chain and tends to a plateau after the DP around 114,i.e. the long chain structure of POE is favourable to the antithrombogenicityof its copolymers ;moreover, the extent of the improvement ofantithrombogenicity also relates to the PEGMM content of the copolymers and the kind of the matrix that the POE chains are located on. These results are consistent with the anticipation of the hypothesis of maintaining proteins normal conformations for blood compatible bioraaterials.展开更多
基金Supported by National Department Public Benefit Research Foundation(201203013)Modern Agricultural Industry Technology System(CARS-11-B-15)+2 种基金IPNI Project(JIANGSU-10)Special Fund for Agro-scientific Research in the Public Interest(201003014-1-2)Jiangsu Agriculture S&T Self-Innovation Project[CX(12)3037]~~
文摘[Objective] The aim was to explore release characteristics of vinyl chlo- ride-vinyl acetate copolymer controlled-release N fertilizer and the effects on minerat nitrogen in soils. [Method] Vinyl chloride-vinyl acetate copolymer and hydroxyl-modi- fied VCNAc were taken as coating materials to prepare slow release fertilizer. Nutri- ent release characteristics of VC/VAc slow release fertilizer was evaluated by water immersion method and the effects of VC/VAc slow release fertilizer on mineral ni- trogen were researched by pot experiment. [Result] The release periods of VC-VAc controlled-release urea and hydroxyl-modified VC/VAc coated urea were 60 and 50 d, respectively. Furthermore, the content of ammonium nitrogen reached the peak on the 30th d and the content of nitrate nitrogen reached the peak on the 60th d in soils in treatments with VCNAc and hydroxyl-modified VC/VAc; the content of nitrate nitrogen rose again on the 120th d in the treatment with VC/VAc. In terms of wheat yield, different treatments showed insignificant differences and rice yield in the treatment with VCNAc was significantly higher than that in the treatment with hy- droxyl-modified VCNAc （P〈0.05）. [Conclusion] The release days of slow controlled- release fertilizer vary upon pot experiment method and water immersion method. Slow controlled-release fertilizer is not suitable for monoculture, due to long fertilizer efficiency, but multiple cropping would be optimal for its role to be fully exploited.
文摘The discarded feathers / ethylene vinyl acetate copolymer( EVA) thermoplastic composite materials was obtained with discarded feathers as reinforced material and EVA powders as matrix material by hot pressing method. Sound absorption properties were studied by changing mass ratio of discarded feathers and EVA,thickness of composite materials,hot pressing pressure and hot pressing temperature. It was found that the sound absorption properties of composite materials were good when the mass ratio of discarded feathers and EVA was 1: 1,thickness of composite materials was 30 mm,hot pressing pressure was 8 MPa,and hot pressing temperature was 80 ℃. Under the optimum conditions,the effect of composite density on sound absorption property was analyzed. In a certain range,the sound absorption property was enhanced with the decrease of the composite density.When the composite density was 0. 1g /cm^3, the maximum absorption coefficient was 0.96. Finally,the capillary theory was used to calculate the maximum sound absorption coefficient of discarded feathers / EVA thermoplastic composite materials. The good agreements of experimental results and calculated results proved the validity of the theoretical models.
基金Supported by the National Natural Science Foundation of China.
文摘Bright blue polymer light-emitting diodes have been fabricated by using the poly(pphenylenevinylene)-based copolymers with 10 C long aliphatic chains as the electroluminescent layers,PBD in PMMA and Alq_(3) as the electron-transporting layers,and aluminum as the cathode.The multilayer structure devices show 190cd/m^(2) light-emitting brightness at 460nm,15 V turn-on vol-tage.It is found that the intensities of photoluminescence and electroluminescence(EL)increase with increasing aliphatic chain length,the EL intensity and operation stability of these polymer light-emitting diodes can be improved by reasonable design of the structure.
基金Sponsored by Project in National Key Technology R&D Program(2006BAE03B05-2)
文摘Sepiolite （S9, B10, B20, B40） and boehmite have been added to an intumecent flame retardant （IFR） system to produce the halogen-free and fire-resistant ethylene-vinyl acetate copolymer （EVM） rubber. The rubber contains ammonium polyphosphate （APP） as acid source, double pentaerythritol （D-PER） as carbon source and melamine （MN） as gas source. The effects of nano-filler sepiolite and boehmite on the fire-resistant property of EVM rubber based on IFR system were investigated. The test results show that the system with nano-filler of sepiolite B10 has the best fire-resistant property. The process of smoke emission and thermal decomposition, the element composition of char surface and the micro morphology of intumecent char layer of the EVM IFR system with nano-filler were also studied by NBS chamber, thermogravimetric （TG） analysis, X- ray photoelectron spectroscopy （XPS） and scanning electron microscope （SEM）.
基金Project (21176264) supported by the National Natural Science Foundation of ChinaProject (11JJ2010) supported by Hunan Provincial Natural Science Foundation of ChinaProject (LC13076) supported by Undergraduate Innovation Foundation of Central South University,China
文摘Copolymer of maleic acid and acrylic acid （PMA-100）, combining with polyvinyl butyral （PVB） ultrafiltration membrane was used for the removal of Mn（II） from waste water by complexation-ultrafiltration. The carboxylic group content of PMA-100 and the rate of complexation reaction were measured. Effects of the mass ratio of PMA-100 to Mn（II） （n）, pH, background electrolyte, etc on the rejection rate （R） and permeate flux （J） were investigated. The results show that carboxylic group content of PMA-100 is 9.5 mmol/g. The complexation of Mn（II） with PMA-100 is rapid and completed within 5 min at pH 6.0. Both R and J increase with pH increasing in the range of 2.5-7.0, and R increases with the increase of n at pH 6.0 while J is little affected. The background electrolyte leads to the decrease of R, and CaCl2 has much greater effect on R than NaCl at the same ionic strength.
文摘Poly （ethyleneglycol monomethylether） methacrylate （PEGMM）was synthesized by means of the reaction of methacrylyl chloride with sodium monomethylpolyethyleneglycoxide and was characterized by FTIR,;H-NMR,and ultraviolet spectrometries. A series of poly （vinyl alcohol）-graft-PEGMM （PVA-g-PEGMM ）and methyl methacrylate-PEGMM copolymer （PMMA-PEGMM） were prepared and tested for antithrombogenicity in vitro. The results indicate that the antithrombogenicity of the copolymers basically increases with the increasing of the DP of polyoxyethylene （POE） chain and tends to a plateau after the DP around 114,i.e. the long chain structure of POE is favourable to the antithrombogenicityof its copolymers ;moreover, the extent of the improvement ofantithrombogenicity also relates to the PEGMM content of the copolymers and the kind of the matrix that the POE chains are located on. These results are consistent with the anticipation of the hypothesis of maintaining proteins normal conformations for blood compatible bioraaterials.
