A new type of green reactive powder concrete (GRPC) with compressive strength of 200 MPa is prepared by utilizing composite mineral admixtures, natural fine aggregates, and short and fine steel fibers. The quasi-stati...A new type of green reactive powder concrete (GRPC) with compressive strength of 200 MPa is prepared by utilizing composite mineral admixtures, natural fine aggregates, and short and fine steel fibers. The quasi-static mechanical properties (mechanical strength, toughness, fracture energy and interfacial bonding strength) of GRPC specimens, cured in three different types of regimes, are investigated. The experimental results show that the mechanical properties of the C200 GRPC made with the powder binders that is composed of 40% of Portland cement, 25% of ultra fine slag, 25% of ultra fine fly ash and 10% of silica fume are better than the others'. The corresponding compressive strength, flexural strength and fracture energy are more than 200 MPa, and 30 000 J/ m2 respectively. The dynamic tensile behavior of the C200 GRPC is also investigated through the split Hopkinson pressure bar (SHPB) according to the spalling phenomenon. The dynamic testing results demonstrate that strain rate has an important effect on the dynamic tensile behavior of GRPC. With the increase of strain rate, its peak stress and relevant strain increase. The GRPC exhibits an excellent strain ratio stiffening effect under the dynamic tensile load with high strain ratio, resulting in a significant change of the fracture pattern.展开更多
A kind of hybrid membrane process, which integrated powdered activated carbon (PAC) with membrane bioreactor (MBR), was designed for bench scale experiment for micro-polluted surface water treatment. Molecular weight ...A kind of hybrid membrane process, which integrated powdered activated carbon (PAC) with membrane bioreactor (MBR), was designed for bench scale experiment for micro-polluted surface water treatment. Molecular weight analysis was used to evaluate the efficiency of each unit process and the integration of them. The result of analysis indicated that organic molecules in the treated water from PAC-MBR process were concentrated on the section of below 1000, while PAC adsorption could enhance the removal efficiency of this section due to the high percent of biodegradation recalcitrant organic matter with low molecular weight. It was demonstrated that PAC adsorption and biological treatment promoted each other in PAC-MBR process, with a removal efficiency of 70% for COD Mn and UV 254, 100% for UV 410 and 92% for ammonia nitrogen in its stable stage.展开更多
Phosphorous slag （PHS）, ground granulated blast-furnace slag （GGBS） and fly ash （FA） were used as replacements of Portland cement to modify the microstruc^xe of recycled aggregate concrete （RAC）. A new manufac...Phosphorous slag （PHS）, ground granulated blast-furnace slag （GGBS） and fly ash （FA） were used as replacements of Portland cement to modify the microstruc^xe of recycled aggregate concrete （RAC）. A new manufacturing method named ＂W3T4＂ was proposed to improve the performances of interracial transition zone （ITZ） between recycled aggregate and mortar. The mechanical properties and the durability of RAC were tested, which show that this new manufacturing method improves the properties of RAC, and the GGBS with finest size makes a great contribution to the performance of RAC due to its better filling effect and much earlier pozzolanic reaction. Combined with GGBS, the effects of PHS on the retardation of setting time can be alleviated and the synergistic effect helps to make a more compact RAC. For the RAC with 25% of the recycled aggregate （RA） replacement and 10% PHS ＋ 10% GGBS additives, the compressive strength increases by 25.4%, but the permeability decreases by 64.3% with respect to the reference concrete made with nature aggregates. The micro-mechanisms of these improvements were investigated by the scanning electron microscope （SEM）. The SEM images show that the new manufacturing method, adding superfine pozzolanic powders and super-plasticizer benefits, makes a much denser ITZ in RAC.展开更多
Cs0.35V2O5 was successfully synthesized as cathode material for lithium secondary battery by the rheological phase reaction method from Cs2CO3 and NH4VO3. The Cs0.35V2O5/Cu composite material was prepared by the displ...Cs0.35V2O5 was successfully synthesized as cathode material for lithium secondary battery by the rheological phase reaction method from Cs2CO3 and NH4VO3. The Cs0.35V2O5/Cu composite material was prepared by the displacement reaction in CuSO4 solution using zinc powder as a reductant. The structure and electrochemical property of the so-prepared powders were characterized by means of XRD （powder X-ray diffraction） and the galvanostatic discharge-charge techniques. The results show that the electrochemical property of Cs0.35V2O5/Cu composite material is significantly improved compared to the bulk Cs0.35V2O5 material. The Cs0.35V2O5/Cu composite material exhibits the first discharge capacity as high as 164.3 mAh.g -1 in the range of 4.2-1.8V at a current rate of 10 mA.g-1 and remains at a stable discharge capacity of about 110 mAh.g-1 within 40 cycles.展开更多
This paper discussed impact of temperature on the size distribution in preparing ultrafine silica from rice husk.The samples prepared were analyzed with infrared spectrum,and the relation between the particle size and...This paper discussed impact of temperature on the size distribution in preparing ultrafine silica from rice husk.The samples prepared were analyzed with infrared spectrum,and the relation between the particle size and intensity of characteristic absorption peak of IR at center around 1 100 cm-1 was disscussed with the baseline method.Results show that when the temperature is 650 ℃ and roasting time is 11 h,at optimal reaction conditions,the size distribution of the ultrafine silica powder prepared is relatively concentrated,and the average particle size is 199.5 nm.Moreover,the characteristic absorption band of IR is broadening gradually along with particle size decreasing.展开更多
Recently,research of crystalline-state transformation involving the removal/inclusion of guest molecules in porous coordination polymers(PCPs) was underway.Crystalline-state transformation,especially,single-crystal to...Recently,research of crystalline-state transformation involving the removal/inclusion of guest molecules in porous coordination polymers(PCPs) was underway.Crystalline-state transformation,especially,single-crystal to single-crystal(SC-SC) transformation as new method for the direct observation of host-guest chemistry,can reveal the intrinsic relevance and interaction between the framework and guest molecules.This review describes our work concerning PCPs and recent investigations of others,within the last four years,from the viewpoint of crystalline-state transformations of PCPs on guest removal or inclusion processes.Ligand substitution reaction and postsynthetic modification of PCPs in SC-SC fashion which were distinguished from conventional crystalline-state transformation triggered by guest removal or exchange were highlighted in this review.The research status of crystalline-state transformation in China was briefly introduced as well.Series of structure analysis techniques including single-crystal X-ray diffraction,powder X-ray diffraction,neutron diffraction,inelastic neutron scattering as well as the application of synchrotron radiation light source will inevitably promote the advance of study of crystalline-state transformation.And as a hotspot,deep investigations of crystalline-state transformation also help us to overcome the challenge of achieving multifunction and the correlation among them,such as sorption,magnetism,optical or electrical properties simultaneously in PCPs and contribute to design stimulate-oriented porous intelligent materials in the future.展开更多
基金Supported by Jiangsu Province Natural Science Foundation Project (No. BK 20065)China National Military Engineering Project (No. A1420060186)
文摘A new type of green reactive powder concrete (GRPC) with compressive strength of 200 MPa is prepared by utilizing composite mineral admixtures, natural fine aggregates, and short and fine steel fibers. The quasi-static mechanical properties (mechanical strength, toughness, fracture energy and interfacial bonding strength) of GRPC specimens, cured in three different types of regimes, are investigated. The experimental results show that the mechanical properties of the C200 GRPC made with the powder binders that is composed of 40% of Portland cement, 25% of ultra fine slag, 25% of ultra fine fly ash and 10% of silica fume are better than the others'. The corresponding compressive strength, flexural strength and fracture energy are more than 200 MPa, and 30 000 J/ m2 respectively. The dynamic tensile behavior of the C200 GRPC is also investigated through the split Hopkinson pressure bar (SHPB) according to the spalling phenomenon. The dynamic testing results demonstrate that strain rate has an important effect on the dynamic tensile behavior of GRPC. With the increase of strain rate, its peak stress and relevant strain increase. The GRPC exhibits an excellent strain ratio stiffening effect under the dynamic tensile load with high strain ratio, resulting in a significant change of the fracture pattern.
文摘A kind of hybrid membrane process, which integrated powdered activated carbon (PAC) with membrane bioreactor (MBR), was designed for bench scale experiment for micro-polluted surface water treatment. Molecular weight analysis was used to evaluate the efficiency of each unit process and the integration of them. The result of analysis indicated that organic molecules in the treated water from PAC-MBR process were concentrated on the section of below 1000, while PAC adsorption could enhance the removal efficiency of this section due to the high percent of biodegradation recalcitrant organic matter with low molecular weight. It was demonstrated that PAC adsorption and biological treatment promoted each other in PAC-MBR process, with a removal efficiency of 70% for COD Mn and UV 254, 100% for UV 410 and 92% for ammonia nitrogen in its stable stage.
基金Project(51178417)supported by the National Natural Science Foundation of ChinaProject(2012R10025)supported by the Qianjiang Talent Plan of Zhejiang Province,China+2 种基金Project(2012HY006B)supported by the Marine Cross-Guide Research Funds of Zhejiang University,ChinaProject(2013FZA4015)supported by the Fundamental Research Funds for the Central Universities,ChinaProject supported by the Department of Construction of Zhejiang Province,China
文摘Phosphorous slag （PHS）, ground granulated blast-furnace slag （GGBS） and fly ash （FA） were used as replacements of Portland cement to modify the microstruc^xe of recycled aggregate concrete （RAC）. A new manufacturing method named ＂W3T4＂ was proposed to improve the performances of interracial transition zone （ITZ） between recycled aggregate and mortar. The mechanical properties and the durability of RAC were tested, which show that this new manufacturing method improves the properties of RAC, and the GGBS with finest size makes a great contribution to the performance of RAC due to its better filling effect and much earlier pozzolanic reaction. Combined with GGBS, the effects of PHS on the retardation of setting time can be alleviated and the synergistic effect helps to make a more compact RAC. For the RAC with 25% of the recycled aggregate （RA） replacement and 10% PHS ＋ 10% GGBS additives, the compressive strength increases by 25.4%, but the permeability decreases by 64.3% with respect to the reference concrete made with nature aggregates. The micro-mechanisms of these improvements were investigated by the scanning electron microscope （SEM）. The SEM images show that the new manufacturing method, adding superfine pozzolanic powders and super-plasticizer benefits, makes a much denser ITZ in RAC.
文摘Cs0.35V2O5 was successfully synthesized as cathode material for lithium secondary battery by the rheological phase reaction method from Cs2CO3 and NH4VO3. The Cs0.35V2O5/Cu composite material was prepared by the displacement reaction in CuSO4 solution using zinc powder as a reductant. The structure and electrochemical property of the so-prepared powders were characterized by means of XRD （powder X-ray diffraction） and the galvanostatic discharge-charge techniques. The results show that the electrochemical property of Cs0.35V2O5/Cu composite material is significantly improved compared to the bulk Cs0.35V2O5 material. The Cs0.35V2O5/Cu composite material exhibits the first discharge capacity as high as 164.3 mAh.g -1 in the range of 4.2-1.8V at a current rate of 10 mA.g-1 and remains at a stable discharge capacity of about 110 mAh.g-1 within 40 cycles.
文摘This paper discussed impact of temperature on the size distribution in preparing ultrafine silica from rice husk.The samples prepared were analyzed with infrared spectrum,and the relation between the particle size and intensity of characteristic absorption peak of IR at center around 1 100 cm-1 was disscussed with the baseline method.Results show that when the temperature is 650 ℃ and roasting time is 11 h,at optimal reaction conditions,the size distribution of the ultrafine silica powder prepared is relatively concentrated,and the average particle size is 199.5 nm.Moreover,the characteristic absorption band of IR is broadening gradually along with particle size decreasing.
基金supported by the National Natural Science Foundation of China(91022015 & 20871034)Guangxi Science Foundation of China (0832001Z)the Program for New Century Excellent Talents in University of the Ministry of Education of China and Guangxi Province (NCET-07-217,2006201)
文摘Recently,research of crystalline-state transformation involving the removal/inclusion of guest molecules in porous coordination polymers(PCPs) was underway.Crystalline-state transformation,especially,single-crystal to single-crystal(SC-SC) transformation as new method for the direct observation of host-guest chemistry,can reveal the intrinsic relevance and interaction between the framework and guest molecules.This review describes our work concerning PCPs and recent investigations of others,within the last four years,from the viewpoint of crystalline-state transformations of PCPs on guest removal or inclusion processes.Ligand substitution reaction and postsynthetic modification of PCPs in SC-SC fashion which were distinguished from conventional crystalline-state transformation triggered by guest removal or exchange were highlighted in this review.The research status of crystalline-state transformation in China was briefly introduced as well.Series of structure analysis techniques including single-crystal X-ray diffraction,powder X-ray diffraction,neutron diffraction,inelastic neutron scattering as well as the application of synchrotron radiation light source will inevitably promote the advance of study of crystalline-state transformation.And as a hotspot,deep investigations of crystalline-state transformation also help us to overcome the challenge of achieving multifunction and the correlation among them,such as sorption,magnetism,optical or electrical properties simultaneously in PCPs and contribute to design stimulate-oriented porous intelligent materials in the future.
