Reducing the chloride content in regenerated iron oxides (RIO) from steel-pickling acid waste economically treated by Ruthner process is the most critical issue for the development of RIO as a useful raw material reso...Reducing the chloride content in regenerated iron oxides (RIO) from steel-pickling acid waste economically treated by Ruthner process is the most critical issue for the development of RIO as a useful raw material resource. In this paper, the results of a new method for characterization and modification of RIO produced in Mobarakeh Steel Complex were reported.展开更多
Acrylate modified polyurethane resin was first synthesized, and interpenetrated with unsaturated polyester resin to form IPNs and gradient IPNs which cured at room temperature. The polymerization process was traced by...Acrylate modified polyurethane resin was first synthesized, and interpenetrated with unsaturated polyester resin to form IPNs and gradient IPNs which cured at room temperature. The polymerization process was traced by an IR spectroscopy technique and the simultaneous interpenetrating techniques were determined. The morphology of these IPNs were estimated by TMA and TEM methods. The results indicated that large amount of interpenetrating and entanglement make T g linked up effectively, and domains between two phases can be in nanometre ranges, which changed with composition ratios. The mechanical properties results showed that IPNs varied from elastomeric to plastic materials. It was noteworthy that, with the introduction of modified groups and the formation of graft construction in IPNs, the miscibility in the systems was improved a lot. These further led to the improved mechanical properties of IPNs with elastomer reinforced and plasticizer toughened as well. The reinforced miscibility between the networks can apparently change mechanical property especially for the gradient ones when the materials are elongated.展开更多
The successful production of higher hydrocarbons from methane depends on the stability or the oxidation rate of the intermediate products. The performances of the BZSM-5 and the modified BZSM-5 catalysts were tested f...The successful production of higher hydrocarbons from methane depends on the stability or the oxidation rate of the intermediate products. The performances of the BZSM-5 and the modified BZSM-5 catalysts were tested for ethylene conversion into higher hydrocarbons. The catalytic experiments were carried out in a fixed-bed micro reactor at atmospheric pressure. The catalysts were characterized using XRD, NH3-TPD, and IR for their structure and acidity. The result suggests that BZSM-5 is a weak acid. The introduction of copper into BZSM-5 improved the acidity of BZSM-5. The conversion of ethylene toward higher hydrocarbons is dependent on the acidity of the catalyst. Only weaker acid site is required to convert ethylene to higher hydrocarbons. The loading of Cu on BZSM-5 improved the selectivity for higher hydrocarbons especially at low percentage. The reactivity of ethylene is dependent on the amount of acidity as well as the presence of metal on the catalyst surface. Cul%BZSM-5 is capable of converting ethylene to higher hydrocarbons. The balances between the metal and acid sites influence the performance of ethylene conversion and higher hydrocarbon selectivity. Higher loading of Cu leads to the formation of COx.展开更多
Electrospinning has been proven as a highly versatile fabrication method for producing nano-structured fibres with controllable morphology,of both the fibres themselves and the void structure of the mats.Additionally,...Electrospinning has been proven as a highly versatile fabrication method for producing nano-structured fibres with controllable morphology,of both the fibres themselves and the void structure of the mats.Additionally,it is possible to use heteroatom doped polymers or to include catalytic precursors in the electrospinning solution to control the surface properties of the fibres.These factors make it an ideal method for the production of electrodes and flow media for a variety of electrochemical devices,enabling reduction in mass transport and activation overpotentials and therefore increasing efficiency.Moreover,the use of biomass as a polymer source has recently gained attention for the ability to embed sustainable principles in the materials of electrochemical devices,complementing their ability to allow an increase in the use of renewable electricity via their application.In this review,the historical and recent developments of electrospun materials for application in redox flow batteries,fuel cells,metal air batteries and supercapacitors are thoroughly reviewed,including an overview of the electrospinning process and a guide to best practice.Finally,we provide an outlook for the emerging use of this process in the field of electrochemical energy devices with the hope that the combination of tailored microstructure,surface functionality and computer modelling will herald a new era of bespoke functional materials that can significantly improve the performance of the devices in which they are used.展开更多
Zinc aluminosilicate glasses containing Li2 O, ZnO , Al2O3 and SiO2 were prepared by conventional melting and quenching technique, and subsequently converted to transparent glass-ceramics by controlled nucleation and...Zinc aluminosilicate glasses containing Li2 O, ZnO , Al2O3 and SiO2 were prepared by conventional melting and quenching technique, and subsequently converted to transparent glass-ceramics by controlled nucleation and crystallization. The glass was melted in a platinum crucible at 1 600 ℃ for 2 h and then two-step heat treated for the nucleation and the crystal growth. The nucleation and crystallization temperatures were determined by differential thermal analysis. Specimens heat-treated on different schedules were analyzed by the X-ray diffraction to determine crystalline phases. Scanning electron microscopy was used to study the glass-ceramics morphology, the grain size and distribution in the residual glass matrix. The reorganization of the amorphous solid was confirmed by FT-IR spectroscopy. The transmittance was measured by a UV-Vis-NIR scanning spectrophotometer .展开更多
Addition of myrcene and 3-methyl-3-penten-2-one followed by cyclization afforded perfume 'Iso-E-Super' with 2(?)-acetyl-2β,3β,8,8-tetramethyl-1,2,3,4,5,6,7,8-octalin as main component on the basis of its spe...Addition of myrcene and 3-methyl-3-penten-2-one followed by cyclization afforded perfume 'Iso-E-Super' with 2(?)-acetyl-2β,3β,8,8-tetramethyl-1,2,3,4,5,6,7,8-octalin as main component on the basis of its spectroscopic data.展开更多
PBO materials possess super mechanical properties and high thermal and chemical resistance due to their special rigid-rod backbones with heterocyclie chemical structure and supermolecular microstrueture. But these str...PBO materials possess super mechanical properties and high thermal and chemical resistance due to their special rigid-rod backbones with heterocyclie chemical structure and supermolecular microstrueture. But these structures may be affected by a series of preparing technologies, among which the coagulant is even more important. In this paper the chemical and microstrueture changes of PBO materials coagulated with different solvents were investigated. Analyses of molecular weight and chemical structure of PBO coagulated indicate that the heteroeyclie ring of PBO will experience cleavage in coagulation and in this stage water plays an important role. The final structure of PBO materials may involve several intermediate structures lying between benzoxazole a,d the open ring. Wide-angle X-ray diffraction （WAXD） 20 scans and scanning probe microscope （ SPM ） show that the microstrueture of PBO materials eoagulated in solvents with different properties will change a lot and those coagulants with the smaller rate of diffusion like methanol can cause more ordered molecule alignment containing fewer voids.展开更多
Europium ternary complex of Eu(NNA) 3(NNA=α-naphthylacetic acid) was embedded in silica matrix at different ratios by sol-gel method. The luminescence properties of silica composites were studied by comparing them wi...Europium ternary complex of Eu(NNA) 3(NNA=α-naphthylacetic acid) was embedded in silica matrix at different ratios by sol-gel method. The luminescence properties of silica composites were studied by comparing them with those of corresponding pure complex by means of excitation, emission spectra and lifetimes. The fluorescence lifetime was prolonged when the pure complex was incorporated in silica matrix. The relative fluorescence intensity and fluorescence lifetimes increased simultaneously with the increase of (Eu(NNA) 3.)展开更多
China has rich lignite reserves which are the proper resources to be liquefied. As its low coalification degree, much hydrogen is wasted. Solvent extraction can save hydrogen and improve its liquefaction performance. ...China has rich lignite reserves which are the proper resources to be liquefied. As its low coalification degree, much hydrogen is wasted. Solvent extraction can save hydrogen and improve its liquefaction performance. The paper studies supercritical methanol treatment of lignite with a device at high temperature and pressure. Experiments mainly focus on the effects of temperature, pressure, catalysts and pretreatment ways on the extraction rate. Results indicate that the extraction rate increases with raising of temperature and pressure below 330 ℃,10 MPa. When temperature exceeds 330 ℃, extraction rate decreases slightly.? After swelling pretreatment in methanol for 8 h, the lignite is treated for 60 min at 330 ℃,8.2 MPa with NaOH as catalyst(1%wt).? The weight ratio of methanol/ Xilinhaote lignite is 5/1.? Under these conditions, the extraction rate can reach 22.88%.展开更多
Computer programs have definitely become indispensable for designing power transformer. Among several applications, computer programs are mostly used for electric field calculation and thus electrical insulation conce...Computer programs have definitely become indispensable for designing power transformer. Among several applications, computer programs are mostly used for electric field calculation and thus electrical insulation concerns. In consequence, studies based on analytical approach to basic studies of correlated problems have become even more important because they form the very basis of knowledge that is necessary to every transformer designer in view of taking all the advantages of computational analyses. On the other hand, one of the most important basic studies consists in the evaluation of voltage surge distribution along transformer windings for which the method of separation of variables has been extensively used thanks to some simplifying assumptions. With this aim, authors have developed and previously published works that show the applicability of an alternative and useful analytical method that is the method of the residues, which requires no simplification to be assumed. In this work, another important step is taken towards proofing the total applicability of this promising method that is through a practical problem. A comparison to the numerical method TLM （transmission line method） is also performed and concordance with TLM and experimental data confirms the proposal of the method of residues can be also applicable to several others problems of electromagnetism.展开更多
A new superposed rule of Mroz's kinematic hardening rule and Ziegler's kinematic hardening rule based on two-surface model is proposed in the paper. Some experimental results on ratchetting of 2014-T6 aluminum...A new superposed rule of Mroz's kinematic hardening rule and Ziegler's kinematic hardening rule based on two-surface model is proposed in the paper. Some experimental results on ratchetting of 2014-T6 aluminum alloy are predicted very well under multiaxial loading. In addition the conformability of the model is discussed for transient cyclic hardening under two kinds of nonproportional cyclic loading paths., i.e. square and rhombic path.展开更多
Photocatalytically reducing CO_(2)by H_(2)O into valuable carbon-containing chemicals is one of the greatest concerns for both scientific and industrial communities,due to its great potential in solving energy and env...Photocatalytically reducing CO_(2)by H_(2)O into valuable carbon-containing chemicals is one of the greatest concerns for both scientific and industrial communities,due to its great potential in solving energy and environmental problems.However,the photocatalytic reduction efficiency is still much lower than the need of large-scale applications.Abilities of photocatalysts in adsorbing CO_(2)and splitting H_(2)O to produce protons are crucial factors determining the photocatalytic reduction efficiency.Significant research efforts have been devoted to addressing the issues on CO_(2)adsorption and proton production.The present review discusses the recent progresses in improving CO_(2)adsorption and proton production on photocatalysts for increasing the photocatalytic reduction efficiency.Future research opportunities and challenges are also discussed.It is hoped that the present review can stimulate more deep insights on adsorption of CO_(2)and production of proton for increasing the photocatalytic reduction efficiency。展开更多
The Paris Agreement has set the goal of carbon neutrality to cope with global climate change.China has pledged to achieve carbon neutrality by 2060,which will strategically change everything in our society.As the main...The Paris Agreement has set the goal of carbon neutrality to cope with global climate change.China has pledged to achieve carbon neutrality by 2060,which will strategically change everything in our society.As the main source of carbon emissions,the consumption of fossil energy is the most profoundly affected by carbon neutrality.This work presents an analysis of how China can achieve its goal of carbon neutrality based on its status of fossil energy utilization.The significance of transforming fossils from energy to resource utilization in the future is addressed,while the development direction and key technologies are discussed.展开更多
文摘Reducing the chloride content in regenerated iron oxides (RIO) from steel-pickling acid waste economically treated by Ruthner process is the most critical issue for the development of RIO as a useful raw material resource. In this paper, the results of a new method for characterization and modification of RIO produced in Mobarakeh Steel Complex were reported.
文摘Acrylate modified polyurethane resin was first synthesized, and interpenetrated with unsaturated polyester resin to form IPNs and gradient IPNs which cured at room temperature. The polymerization process was traced by an IR spectroscopy technique and the simultaneous interpenetrating techniques were determined. The morphology of these IPNs were estimated by TMA and TEM methods. The results indicated that large amount of interpenetrating and entanglement make T g linked up effectively, and domains between two phases can be in nanometre ranges, which changed with composition ratios. The mechanical properties results showed that IPNs varied from elastomeric to plastic materials. It was noteworthy that, with the introduction of modified groups and the formation of graft construction in IPNs, the miscibility in the systems was improved a lot. These further led to the improved mechanical properties of IPNs with elastomer reinforced and plasticizer toughened as well. The reinforced miscibility between the networks can apparently change mechanical property especially for the gradient ones when the materials are elongated.
文摘The successful production of higher hydrocarbons from methane depends on the stability or the oxidation rate of the intermediate products. The performances of the BZSM-5 and the modified BZSM-5 catalysts were tested for ethylene conversion into higher hydrocarbons. The catalytic experiments were carried out in a fixed-bed micro reactor at atmospheric pressure. The catalysts were characterized using XRD, NH3-TPD, and IR for their structure and acidity. The result suggests that BZSM-5 is a weak acid. The introduction of copper into BZSM-5 improved the acidity of BZSM-5. The conversion of ethylene toward higher hydrocarbons is dependent on the acidity of the catalyst. Only weaker acid site is required to convert ethylene to higher hydrocarbons. The loading of Cu on BZSM-5 improved the selectivity for higher hydrocarbons especially at low percentage. The reactivity of ethylene is dependent on the amount of acidity as well as the presence of metal on the catalyst surface. Cul%BZSM-5 is capable of converting ethylene to higher hydrocarbons. The balances between the metal and acid sites influence the performance of ethylene conversion and higher hydrocarbon selectivity. Higher loading of Cu leads to the formation of COx.
文摘Electrospinning has been proven as a highly versatile fabrication method for producing nano-structured fibres with controllable morphology,of both the fibres themselves and the void structure of the mats.Additionally,it is possible to use heteroatom doped polymers or to include catalytic precursors in the electrospinning solution to control the surface properties of the fibres.These factors make it an ideal method for the production of electrodes and flow media for a variety of electrochemical devices,enabling reduction in mass transport and activation overpotentials and therefore increasing efficiency.Moreover,the use of biomass as a polymer source has recently gained attention for the ability to embed sustainable principles in the materials of electrochemical devices,complementing their ability to allow an increase in the use of renewable electricity via their application.In this review,the historical and recent developments of electrospun materials for application in redox flow batteries,fuel cells,metal air batteries and supercapacitors are thoroughly reviewed,including an overview of the electrospinning process and a guide to best practice.Finally,we provide an outlook for the emerging use of this process in the field of electrochemical energy devices with the hope that the combination of tailored microstructure,surface functionality and computer modelling will herald a new era of bespoke functional materials that can significantly improve the performance of the devices in which they are used.
基金Funded bythe Chinese Education Ministry(No.KB20026)
文摘Zinc aluminosilicate glasses containing Li2 O, ZnO , Al2O3 and SiO2 were prepared by conventional melting and quenching technique, and subsequently converted to transparent glass-ceramics by controlled nucleation and crystallization. The glass was melted in a platinum crucible at 1 600 ℃ for 2 h and then two-step heat treated for the nucleation and the crystal growth. The nucleation and crystallization temperatures were determined by differential thermal analysis. Specimens heat-treated on different schedules were analyzed by the X-ray diffraction to determine crystalline phases. Scanning electron microscopy was used to study the glass-ceramics morphology, the grain size and distribution in the residual glass matrix. The reorganization of the amorphous solid was confirmed by FT-IR spectroscopy. The transmittance was measured by a UV-Vis-NIR scanning spectrophotometer .
文摘Addition of myrcene and 3-methyl-3-penten-2-one followed by cyclization afforded perfume 'Iso-E-Super' with 2(?)-acetyl-2β,3β,8,8-tetramethyl-1,2,3,4,5,6,7,8-octalin as main component on the basis of its spectroscopic data.
基金Sponsored by the National High Technology Research and Development Program of China(Grant No. 2002AA305109) and Innovational Project in Space Flight Science and Technology(Grant No.2409035).
文摘PBO materials possess super mechanical properties and high thermal and chemical resistance due to their special rigid-rod backbones with heterocyclie chemical structure and supermolecular microstrueture. But these structures may be affected by a series of preparing technologies, among which the coagulant is even more important. In this paper the chemical and microstrueture changes of PBO materials coagulated with different solvents were investigated. Analyses of molecular weight and chemical structure of PBO coagulated indicate that the heteroeyclie ring of PBO will experience cleavage in coagulation and in this stage water plays an important role. The final structure of PBO materials may involve several intermediate structures lying between benzoxazole a,d the open ring. Wide-angle X-ray diffraction （WAXD） 20 scans and scanning probe microscope （ SPM ） show that the microstrueture of PBO materials eoagulated in solvents with different properties will change a lot and those coagulants with the smaller rate of diffusion like methanol can cause more ordered molecule alignment containing fewer voids.
文摘Europium ternary complex of Eu(NNA) 3(NNA=α-naphthylacetic acid) was embedded in silica matrix at different ratios by sol-gel method. The luminescence properties of silica composites were studied by comparing them with those of corresponding pure complex by means of excitation, emission spectra and lifetimes. The fluorescence lifetime was prolonged when the pure complex was incorporated in silica matrix. The relative fluorescence intensity and fluorescence lifetimes increased simultaneously with the increase of (Eu(NNA) 3.)
文摘China has rich lignite reserves which are the proper resources to be liquefied. As its low coalification degree, much hydrogen is wasted. Solvent extraction can save hydrogen and improve its liquefaction performance. The paper studies supercritical methanol treatment of lignite with a device at high temperature and pressure. Experiments mainly focus on the effects of temperature, pressure, catalysts and pretreatment ways on the extraction rate. Results indicate that the extraction rate increases with raising of temperature and pressure below 330 ℃,10 MPa. When temperature exceeds 330 ℃, extraction rate decreases slightly.? After swelling pretreatment in methanol for 8 h, the lignite is treated for 60 min at 330 ℃,8.2 MPa with NaOH as catalyst(1%wt).? The weight ratio of methanol/ Xilinhaote lignite is 5/1.? Under these conditions, the extraction rate can reach 22.88%.
文摘Computer programs have definitely become indispensable for designing power transformer. Among several applications, computer programs are mostly used for electric field calculation and thus electrical insulation concerns. In consequence, studies based on analytical approach to basic studies of correlated problems have become even more important because they form the very basis of knowledge that is necessary to every transformer designer in view of taking all the advantages of computational analyses. On the other hand, one of the most important basic studies consists in the evaluation of voltage surge distribution along transformer windings for which the method of separation of variables has been extensively used thanks to some simplifying assumptions. With this aim, authors have developed and previously published works that show the applicability of an alternative and useful analytical method that is the method of the residues, which requires no simplification to be assumed. In this work, another important step is taken towards proofing the total applicability of this promising method that is through a practical problem. A comparison to the numerical method TLM （transmission line method） is also performed and concordance with TLM and experimental data confirms the proposal of the method of residues can be also applicable to several others problems of electromagnetism.
基金The project supported by the National Natural Science Foundation of China
文摘A new superposed rule of Mroz's kinematic hardening rule and Ziegler's kinematic hardening rule based on two-surface model is proposed in the paper. Some experimental results on ratchetting of 2014-T6 aluminum alloy are predicted very well under multiaxial loading. In addition the conformability of the model is discussed for transient cyclic hardening under two kinds of nonproportional cyclic loading paths., i.e. square and rhombic path.
基金The authors acknowledge the financial support from National Natural Science Foundation of China(21922807).
文摘Photocatalytically reducing CO_(2)by H_(2)O into valuable carbon-containing chemicals is one of the greatest concerns for both scientific and industrial communities,due to its great potential in solving energy and environmental problems.However,the photocatalytic reduction efficiency is still much lower than the need of large-scale applications.Abilities of photocatalysts in adsorbing CO_(2)and splitting H_(2)O to produce protons are crucial factors determining the photocatalytic reduction efficiency.Significant research efforts have been devoted to addressing the issues on CO_(2)adsorption and proton production.The present review discusses the recent progresses in improving CO_(2)adsorption and proton production on photocatalysts for increasing the photocatalytic reduction efficiency.Future research opportunities and challenges are also discussed.It is hoped that the present review can stimulate more deep insights on adsorption of CO_(2)and production of proton for increasing the photocatalytic reduction efficiency。
文摘The Paris Agreement has set the goal of carbon neutrality to cope with global climate change.China has pledged to achieve carbon neutrality by 2060,which will strategically change everything in our society.As the main source of carbon emissions,the consumption of fossil energy is the most profoundly affected by carbon neutrality.This work presents an analysis of how China can achieve its goal of carbon neutrality based on its status of fossil energy utilization.The significance of transforming fossils from energy to resource utilization in the future is addressed,while the development direction and key technologies are discussed.
