The rates of electron exchange between oxidized and reduced forms of sev- eral derivatives of ferrocene(1-3)have been measured in acetonitrile by the NMR line h(?)oadening method at 25℃。It was found that the r(?)tes...The rates of electron exchange between oxidized and reduced forms of sev- eral derivatives of ferrocene(1-3)have been measured in acetonitrile by the NMR line h(?)oadening method at 25℃。It was found that the r(?)tes vary with the lengtn of the substitutent chain and the potential of E_(Fe(Ⅲ)/Fe(Ⅱ))in the ferrocene derivatives.展开更多
Nitric oxide（NO）,a bioactive signaling molecule,serves as an antioxidant and anti-stress agent under abiotic stress.A hydroponics experiment was conducted to investigate the effects of sodium nitroprusside（SNP）,a ...Nitric oxide（NO）,a bioactive signaling molecule,serves as an antioxidant and anti-stress agent under abiotic stress.A hydroponics experiment was conducted to investigate the effects of sodium nitroprusside（SNP）,a NO donor,on tomato seedlings exposed to 50 μmol L-1CuCl 2.The results show that copper is primarily stored in the soluble cell sap fraction in the roots,especially after treatment with Cu＋SNP treatment,which accounted for 66.2% of the total copper content.The copper concentration gradually decreased from the roots to the leaves.In the leaves,exogenous NO induces the storage of excess copper in the cell walls.Copper stress decreases the proportion of copper integrated with pectates and proteins,but exogenous NO remarkably reverses this trend.The alleviating effect of NO is blocked by hemoglobin.Thus,exogenous NO is likely involved in the regulation of the subcellular copper concentrations and its chemical forms under copper stress.Although exogenous NO inhibited the absorption and transport of excess copper to some extent,the copper accumulation in tomato seedlings significantly increased under copper stress.The use of exogenous NO to enhance copper tolerance in some plants is a promising method for copper remediation.展开更多
Low and medium carbon steels were aluminized by the pack aluminizing technique using halideactivated pure-Al and Fe-Al packs. The effect of mixture composition, aluminizing temperatureand time and C content of the ste...Low and medium carbon steels were aluminized by the pack aluminizing technique using halideactivated pure-Al and Fe-Al packs. The effect of mixture composition, aluminizing temperatureand time and C content of the steel substrate on the structure and thickness of the aluminidelayer, and on the oxidation resistance was investigated. The optimum oxidation resistance canbe achieved with a low carbon steel substrate when the intermetallic phases Fe3Al and FeAlform the surface of the aluminide layer. In this case, the Al concentration at the surface of thealuminide coating is at least ≥15 wt pct. Formation of high Al concentration phases (FeAl3 andFe2Al5) during aluminizing should be avoided as they tend to embrittle the aluminide layer andreduce its oxidation resistance.展开更多
Many gas turbine components are made from nickel alloy sheet. Most are used for directing or containing gases at high temperatures and pressures where metal temperatures can be as high as 1090℃ (2000°F). These a...Many gas turbine components are made from nickel alloy sheet. Most are used for directing or containing gases at high temperatures and pressures where metal temperatures can be as high as 1090℃ (2000°F). These applications included combustor systems, casings and liners, transition and exhaust ducting, afterburners, and thrust reversere. Light weight components and sub-assemblies call for alloy sheet with high levels of stength and oxidation resistance. Complex component design calls for excellent ductility and ease of fabrication.The wide range of nickel alloy sheet alloys presently used in aircraft and land-based gas turbines is briefly described and typical properties presented. New sheet alloy developments, involving INCONEL￣* alloys 625LCF, 718SPF and MA754, are presented including the process routes involved and material properties.展开更多
Hydrogen internal combustion engines are up-and-coming power devices in the current energy field.However,engine lubricants are prone to contact with hydrogen and water vapor during operation,and the impact of these ga...Hydrogen internal combustion engines are up-and-coming power devices in the current energy field.However,engine lubricants are prone to contact with hydrogen and water vapor during operation,and the impact of these gases on the tribological properties of the lubricants has not yet been clearly studied.In this work,the tribological performance and mechanism of emulsified lubricants with varying hydrogen content were investigated.The results demonstrated that the width and the depth of the wear track on the GCr15 steel blocks decreased by 86.8%and 80.4%,respectively,as the volume ratio of hydrogen gas to oil increased from 0 to 100 vol%.The conversion of complete oxide layer(FeOOH–Fe_(2)O_(3))and composite oxide layer(Fe–FeO–FeOOH–Fe_(2)O_(3))at the frictional interface was proposed as the wear mechanism,and this mechanism was confirmed utilizing optical microscopy,contact three-dimensional(3D)profilometry,scanning electron microscopy(SEM),and X-ray photoelectron spectroscopy(XPS).A complete oxide layer lubricated by pure oil results in severe adhesive wear at the friction interface,whereas a composite oxide layer under 80–100 vol%H_(2)/oil emulsified lubricants was discovered to reduce oxidation corrosion and wear.The characteristics of this wear mechanism can be applied to reduce wear in tribo-pairs and lubricant designs of hydrogen internal combustion engines.展开更多
文摘The rates of electron exchange between oxidized and reduced forms of sev- eral derivatives of ferrocene(1-3)have been measured in acetonitrile by the NMR line h(?)oadening method at 25℃。It was found that the r(?)tes vary with the lengtn of the substitutent chain and the potential of E_(Fe(Ⅲ)/Fe(Ⅱ))in the ferrocene derivatives.
基金supported partially by the National Natural Science Foundation of China (31201619)Profession Expert Group of Facility Cultivation and Engineering (CARS25-D-03)the Sci-Tech Development Project of Tai’an City, China (32606)
文摘Nitric oxide（NO）,a bioactive signaling molecule,serves as an antioxidant and anti-stress agent under abiotic stress.A hydroponics experiment was conducted to investigate the effects of sodium nitroprusside（SNP）,a NO donor,on tomato seedlings exposed to 50 μmol L-1CuCl 2.The results show that copper is primarily stored in the soluble cell sap fraction in the roots,especially after treatment with Cu＋SNP treatment,which accounted for 66.2% of the total copper content.The copper concentration gradually decreased from the roots to the leaves.In the leaves,exogenous NO induces the storage of excess copper in the cell walls.Copper stress decreases the proportion of copper integrated with pectates and proteins,but exogenous NO remarkably reverses this trend.The alleviating effect of NO is blocked by hemoglobin.Thus,exogenous NO is likely involved in the regulation of the subcellular copper concentrations and its chemical forms under copper stress.Although exogenous NO inhibited the absorption and transport of excess copper to some extent,the copper accumulation in tomato seedlings significantly increased under copper stress.The use of exogenous NO to enhance copper tolerance in some plants is a promising method for copper remediation.
文摘Low and medium carbon steels were aluminized by the pack aluminizing technique using halideactivated pure-Al and Fe-Al packs. The effect of mixture composition, aluminizing temperatureand time and C content of the steel substrate on the structure and thickness of the aluminidelayer, and on the oxidation resistance was investigated. The optimum oxidation resistance canbe achieved with a low carbon steel substrate when the intermetallic phases Fe3Al and FeAlform the surface of the aluminide layer. In this case, the Al concentration at the surface of thealuminide coating is at least ≥15 wt pct. Formation of high Al concentration phases (FeAl3 andFe2Al5) during aluminizing should be avoided as they tend to embrittle the aluminide layer andreduce its oxidation resistance.
文摘Many gas turbine components are made from nickel alloy sheet. Most are used for directing or containing gases at high temperatures and pressures where metal temperatures can be as high as 1090℃ (2000°F). These applications included combustor systems, casings and liners, transition and exhaust ducting, afterburners, and thrust reversere. Light weight components and sub-assemblies call for alloy sheet with high levels of stength and oxidation resistance. Complex component design calls for excellent ductility and ease of fabrication.The wide range of nickel alloy sheet alloys presently used in aircraft and land-based gas turbines is briefly described and typical properties presented. New sheet alloy developments, involving INCONEL￣* alloys 625LCF, 718SPF and MA754, are presented including the process routes involved and material properties.
基金supported by the National Natural Science Foundation of China(No.52306038)the Scientific Research and Technology Development Project of Petroleum Company Limited(No.2022DJ5912).
文摘Hydrogen internal combustion engines are up-and-coming power devices in the current energy field.However,engine lubricants are prone to contact with hydrogen and water vapor during operation,and the impact of these gases on the tribological properties of the lubricants has not yet been clearly studied.In this work,the tribological performance and mechanism of emulsified lubricants with varying hydrogen content were investigated.The results demonstrated that the width and the depth of the wear track on the GCr15 steel blocks decreased by 86.8%and 80.4%,respectively,as the volume ratio of hydrogen gas to oil increased from 0 to 100 vol%.The conversion of complete oxide layer(FeOOH–Fe_(2)O_(3))and composite oxide layer(Fe–FeO–FeOOH–Fe_(2)O_(3))at the frictional interface was proposed as the wear mechanism,and this mechanism was confirmed utilizing optical microscopy,contact three-dimensional(3D)profilometry,scanning electron microscopy(SEM),and X-ray photoelectron spectroscopy(XPS).A complete oxide layer lubricated by pure oil results in severe adhesive wear at the friction interface,whereas a composite oxide layer under 80–100 vol%H_(2)/oil emulsified lubricants was discovered to reduce oxidation corrosion and wear.The characteristics of this wear mechanism can be applied to reduce wear in tribo-pairs and lubricant designs of hydrogen internal combustion engines.
