Cu–Mn bimetal catalysts were prepared to remove nitrogen oxides(NOx)from diesel engine exhaust at low temperatures.At a Cu/Mn ratio of 3:2,the NOx conversions at 200°C reached 65%and 90%on Cu–Mn/ZSM‐5 and Cu–...Cu–Mn bimetal catalysts were prepared to remove nitrogen oxides(NOx)from diesel engine exhaust at low temperatures.At a Cu/Mn ratio of 3:2,the NOx conversions at 200°C reached 65%and 90%on Cu–Mn/ZSM‐5 and Cu–Mn/SAPO‐34,respectively.After a hydrothermal treatment and reaction in the presence of C3H6,the activity of Cu–Mn/SAPO‐34 was more stable than that of Cu–Mn/ZSM‐5.No obvious variations in the crystal structure or dealumination were observed,whereas the physical structure was best maintained in Cu–Mn/SAPO‐34.The atomic concentration of Cu on the surface of Cu–Mn/SAPO‐34 was quite stable,and the consumption of octahedrally coordinated Cu2+could be recovered.Conversely,the proportion of octahedrally coordinated Cu2+on the surface of Cu–Mn/ZSM‐5 significantly decreased.Therefore,besides the structure,the redox cycle between Cu+and octahedrally coordinated Cu2+played an important role in the stability of the catalysts.展开更多
Healthy sporophytes of two gametophyte mutants of Laminariajaponica with different heat resistances： kelp 901 （901, with comparatively stronger heat-resistance） and Rongcheng No. I （RC, sensitive to heat stress）,...Healthy sporophytes of two gametophyte mutants of Laminariajaponica with different heat resistances： kelp 901 （901, with comparatively stronger heat-resistance） and Rongcheng No. I （RC, sensitive to heat stress）, were respectively collected during October to December 2002 from Yantai and Rongcheng Sea Farm in the Shandong Peninsula of China. The contents of some biochemical materials and antioxidant capacity were analyzed under controlled laboratory conditions to identify if there is any relation between the overall antioxidant capacity and the heat-resistance in L. japonica and to understand possible mechanism of heat-resistance. Results show that： （1） the overall antioxidant capacity in healthy sporophyte of 901, such as vitamin E, polyphenol, and ascorbic acid contents and the enzymatic activity of SOD, POD, CAT, Gpx, PPO, and PAL, were not always higher than that of RC under controlled laboratory conditions, and no significance （P〉0.05） was shown in total antioxidant capacity （T-AOC） in 901 and RC. Result suggested that the difference in antioxidant capacity was not a decisive factor for different heat-resistances in L. japonica; （2） the simultaneous assay on isozymes was carried out using vertical polyacrylamide gel electrophoresis （PAGE）. Considerable differences in peroxide （PRX）, malate dehydrogenase （MDH）, malic enzyme （ME）, polyphenol oxidase （PPO） and glutamate dehydrogenase （GDH） were obtained in 901 and RC from either the band number, relative mobility （Rf）, or staining intensity, and ME could be used as an indicator to distinguish healthy sporophyte of 901 and RC under controlled laboratory conditions.展开更多
Morphology-controlled synthesis of copper vanadate nanocrystals is of great significance in electrochemical sensing applications.A facile hydrothermal process for synthesizing copper vanadate nanocrystals with various...Morphology-controlled synthesis of copper vanadate nanocrystals is of great significance in electrochemical sensing applications.A facile hydrothermal process for synthesizing copper vanadate nanocrystals with various morphologies(e.g.,nanoparticles,nanobelts and nanoflowers)was reported.Phase,morphology and electrochemical performance of the as-synthesized copper vanadate nanocrystals were characterized by X-ray diffraction(XRD),scanning electron microscope(SEM)and cyclic-voltammogram(CV)techniques.The results revealed that the morphologies of the Cu3V2O7(OH)2·2H2O(CVOH)nanocrystals could be controlled by changing copper salts,surfactants and pH values.The CVOH samples showed enhanced electrochemical response to ascorbic acid.Comparatively,the CVOH nanobelts had the higher electrochemical sensing performance than those of CVOH nanoparticles and nanoflowers.The CVOH-nanobelts-modified GCEs had a linear relationship between the peak currents in their CVs and ascorbic acid concentration.The CVOH nanocrystals can be used as potential electrochemical active materials for the determination of ascorbic acid.展开更多
Forming a stable anti-corrosion surface layer on magnesium(Mg)and its alloys has become a major challenge in developing a desirable degradable medical implant in bone.In this study,a porous MgO layer was first formed ...Forming a stable anti-corrosion surface layer on magnesium(Mg)and its alloys has become a major challenge in developing a desirable degradable medical implant in bone.In this study,a porous MgO layer was first formed on Mg by plasma electrolytic oxidation(PEO),and then a Mg-Al layered double hydroxide(LDH)layer was prepared to seal the porous structure of the PEO layer(LDH-2h and LDH-12h)via hydrothermal treatment.The bilayer structure composite coating,which can effectively resist the penetration of surrounding media,is similar to plain Chinese tiles.The in vitro results revealed that compared with other coatings,the LDH-12h composite coating can reduce the release of Mg ions and induce a milder change in pH when immersed in phosphate-buffered saline(PBS).In vitro rat bone marrow stem cell(rBMSC)culture suggested that the LDH-12h composite coating is favorable for cell activity,proliferation and could improve the osteogenic activity of rBMSCs.A subcutaneous implantation test revealed that the as-prepared sample showed enhanced corrosion resistance and histocompatibility in vivo,especially in the LDH-12h group.Moreover,LDH-12h had the lowest rate of degradation and the closest combination with the new bone after being inserted into a rat femur for 12 weeks with no major organ dysfunction.In summary,the asprepared PEO/Mg-Al LDH composite coating is able to improve the corrosion resistance and biocompatibility of Mg and to enhance osteogenic activity in vivo,suggesting its promising prospects for orthopedic applications.展开更多
基金supported by the National Natural Science Foundation of China(51008277)the Natural Science Foundation of Zhejiang Province(LY14E080001)the Key Project of Zhejiang Provincial Science and Technology Program(2012C03003-4)~~
文摘Cu–Mn bimetal catalysts were prepared to remove nitrogen oxides(NOx)from diesel engine exhaust at low temperatures.At a Cu/Mn ratio of 3:2,the NOx conversions at 200°C reached 65%and 90%on Cu–Mn/ZSM‐5 and Cu–Mn/SAPO‐34,respectively.After a hydrothermal treatment and reaction in the presence of C3H6,the activity of Cu–Mn/SAPO‐34 was more stable than that of Cu–Mn/ZSM‐5.No obvious variations in the crystal structure or dealumination were observed,whereas the physical structure was best maintained in Cu–Mn/SAPO‐34.The atomic concentration of Cu on the surface of Cu–Mn/SAPO‐34 was quite stable,and the consumption of octahedrally coordinated Cu2+could be recovered.Conversely,the proportion of octahedrally coordinated Cu2+on the surface of Cu–Mn/ZSM‐5 significantly decreased.Therefore,besides the structure,the redox cycle between Cu+and octahedrally coordinated Cu2+played an important role in the stability of the catalysts.
基金Supported by the National Hi-Tech Research Program (863 Program, No. 2004AA639770)the National Natural Science Foundation of China (No.30270258)Program for New Century Excellent Talents in University (NCET-05-0597).
文摘Healthy sporophytes of two gametophyte mutants of Laminariajaponica with different heat resistances： kelp 901 （901, with comparatively stronger heat-resistance） and Rongcheng No. I （RC, sensitive to heat stress）, were respectively collected during October to December 2002 from Yantai and Rongcheng Sea Farm in the Shandong Peninsula of China. The contents of some biochemical materials and antioxidant capacity were analyzed under controlled laboratory conditions to identify if there is any relation between the overall antioxidant capacity and the heat-resistance in L. japonica and to understand possible mechanism of heat-resistance. Results show that： （1） the overall antioxidant capacity in healthy sporophyte of 901, such as vitamin E, polyphenol, and ascorbic acid contents and the enzymatic activity of SOD, POD, CAT, Gpx, PPO, and PAL, were not always higher than that of RC under controlled laboratory conditions, and no significance （P〉0.05） was shown in total antioxidant capacity （T-AOC） in 901 and RC. Result suggested that the difference in antioxidant capacity was not a decisive factor for different heat-resistances in L. japonica; （2） the simultaneous assay on isozymes was carried out using vertical polyacrylamide gel electrophoresis （PAGE）. Considerable differences in peroxide （PRX）, malate dehydrogenase （MDH）, malic enzyme （ME）, polyphenol oxidase （PPO） and glutamate dehydrogenase （GDH） were obtained in 901 and RC from either the band number, relative mobility （Rf）, or staining intensity, and ME could be used as an indicator to distinguish healthy sporophyte of 901 and RC under controlled laboratory conditions.
基金Projects(51404213,51404214,51574205,51172211)supported by the National Natural Science Foundation of ChinaProjects(14HASTIT011,154100510003)supported by the Program for University Science and Technology Innovation Talents of Henan Province,China+1 种基金Projects(2013M531682,2014T70682)supported by the China Postdoctoral Science FundProject(1421324065)supported by the Development Fund for Outstanding Young Teachers of Zhengzhou University,China
文摘Morphology-controlled synthesis of copper vanadate nanocrystals is of great significance in electrochemical sensing applications.A facile hydrothermal process for synthesizing copper vanadate nanocrystals with various morphologies(e.g.,nanoparticles,nanobelts and nanoflowers)was reported.Phase,morphology and electrochemical performance of the as-synthesized copper vanadate nanocrystals were characterized by X-ray diffraction(XRD),scanning electron microscope(SEM)and cyclic-voltammogram(CV)techniques.The results revealed that the morphologies of the Cu3V2O7(OH)2·2H2O(CVOH)nanocrystals could be controlled by changing copper salts,surfactants and pH values.The CVOH samples showed enhanced electrochemical response to ascorbic acid.Comparatively,the CVOH nanobelts had the higher electrochemical sensing performance than those of CVOH nanoparticles and nanoflowers.The CVOH-nanobelts-modified GCEs had a linear relationship between the peak currents in their CVs and ascorbic acid concentration.The CVOH nanocrystals can be used as potential electrochemical active materials for the determination of ascorbic acid.
基金the National Natural Science Foundation of China(81901048,81921002,81620108006 and 31771044)Shanghai Committee of Science and Technology,China(18410760600)the International Partnership Program of Chinese Academy of Sciences(GJHZ1850)。
文摘Forming a stable anti-corrosion surface layer on magnesium(Mg)and its alloys has become a major challenge in developing a desirable degradable medical implant in bone.In this study,a porous MgO layer was first formed on Mg by plasma electrolytic oxidation(PEO),and then a Mg-Al layered double hydroxide(LDH)layer was prepared to seal the porous structure of the PEO layer(LDH-2h and LDH-12h)via hydrothermal treatment.The bilayer structure composite coating,which can effectively resist the penetration of surrounding media,is similar to plain Chinese tiles.The in vitro results revealed that compared with other coatings,the LDH-12h composite coating can reduce the release of Mg ions and induce a milder change in pH when immersed in phosphate-buffered saline(PBS).In vitro rat bone marrow stem cell(rBMSC)culture suggested that the LDH-12h composite coating is favorable for cell activity,proliferation and could improve the osteogenic activity of rBMSCs.A subcutaneous implantation test revealed that the as-prepared sample showed enhanced corrosion resistance and histocompatibility in vivo,especially in the LDH-12h group.Moreover,LDH-12h had the lowest rate of degradation and the closest combination with the new bone after being inserted into a rat femur for 12 weeks with no major organ dysfunction.In summary,the asprepared PEO/Mg-Al LDH composite coating is able to improve the corrosion resistance and biocompatibility of Mg and to enhance osteogenic activity in vivo,suggesting its promising prospects for orthopedic applications.
