Two-phase equilibria between the ferromagnetic fcc and the paramagnetic fcc phase from 800 ℃ to 900 ℃ in the Co-rich region have been detected by the diffusion couple technique. Two phase separation region of the fc...Two-phase equilibria between the ferromagnetic fcc and the paramagnetic fcc phase from 800 ℃ to 900 ℃ in the Co-rich region have been detected by the diffusion couple technique. Two phase separation region of the fcc has been confirmed along the Curie temperature.The phase equilibria including the present results and the thermodynamic data of the Co-Cr system reported in the literature were analyzed on the basis of the thermodynamic evaluation. A set of thermodynamic values for the liquid, fcc, hcp, bcc, sigma phases was obtained. The calculated phase equilibria were in good agreement with most of the experimental data.展开更多
Tank Cascade Systems(TCS)are the back bone of the dry zone prosperity in Sri Lanka and supply water throughout the year to agricultural lands since the 2nd century BC.The main aim of this study was to understand the n...Tank Cascade Systems(TCS)are the back bone of the dry zone prosperity in Sri Lanka and supply water throughout the year to agricultural lands since the 2nd century BC.The main aim of this study was to understand the nutrient dynamics of small TCS and find out evidence for the sustainability of the system for thousands of years.Malagane tank cascade in the Deduru Oya Basin(the 5th largest river basin展开更多
On December 26,2004,the Indian Ocean tsunami waves hit Sri Lanka resulting in the devastation of the coastal aquifers from saltwater contamination.In an attempt to speed up the cleaning process of the contaminated wat...On December 26,2004,the Indian Ocean tsunami waves hit Sri Lanka resulting in the devastation of the coastal aquifers from saltwater contamination.In an attempt to speed up the cleaning process of the contaminated water in wells,large-scale and intensive campaigns went into cleaning and rehabilitating wells through pumping out saline water(physical cleansing). However,it was unclear whether these attempts improved the well-water quality,especially in terms of salinity due to density driven flow and solute transport phenomenon.Changes in water quality of a sand aquifer on the east coast of Sri Lanka owing to the December 26,2004 tsunami and展开更多
A series of positive electrodes for Ni/MH battery were fabricated by addition of CoO.The morphology and microstructure of the electrodes were examined by SEM and EDS, and electrochemical behavior was investigated in t...A series of positive electrodes for Ni/MH battery were fabricated by addition of CoO.The morphology and microstructure of the electrodes were examined by SEM and EDS, and electrochemical behavior was investigated in three-compartment appliances at room temperature.The electrochemical performance of the positive electrodes with CoO was improved. Under the same charge-discharge cycle, the electrodes with CoO showed higher specific capacity, lower charge mean voltage and higher discharge mean voltage. But ...展开更多
A nanocomposite of manganese dioxide coated manganese hexacyanoferrate was synthesized by a facile co-precipitation method and tested as active electrode material for an electrochemical supercapacitor. A way called &q...A nanocomposite of manganese dioxide coated manganese hexacyanoferrate was synthesized by a facile co-precipitation method and tested as active electrode material for an electrochemical supercapacitor. A way called "Deep electro-oxidation" was used to generate manganese dioxide coated layer for stabilizing the electrode material. The structure and ingredient of the resulting MnHCF/MnO2 composites were characterized by scanning electron microscopy, transmission electron microscopy, X-ray diffraction, and X-ray Photoelectron Spectroscopy. Electrochemical testing showed a capacitance of 225.6 F/g at a sweep rate of 5 mV/s within a voltage range of 1.3 V, and high energy density of 37.2 Wh/kg at a current density of 0.5 A/g in galvanostatic charge/discharge cycling. It is suggested that the two different components, manganese hexacyanoferrate core and manganese dioxide shell, lead to an integrated electrochemical behavior, and an enhanced capacitor. The electrochemical testing and corresponding XPS analysis also demonstrated that the manganese coordinated by cyanide groups via nitrogen atoms in MnHCF did not get involved in the charge storage process during potential cycles.展开更多
NiCrAlY+(ZrO_2+Y_2O_3)thermal barrier coating was prepared on the surface of refractory steel 1Cr18Ni9Ti with plasma spraying technique. The phases and microstructure of the thermal barrier coating were determined by ...NiCrAlY+(ZrO_2+Y_2O_3)thermal barrier coating was prepared on the surface of refractory steel 1Cr18Ni9Ti with plasma spraying technique. The phases and microstructure of the thermal barrier coating were determined by scanning electron microscopy(SEM) and X-ray diffraction(XRD). The results show that the bonding between thermal barrier coating and substrate is sound. The surface hardness of 1Cr18Ni9Ti reaches up to 1000 HV, but that of substrate is only 300HV. The patterns sprayed with CoNiCrAlY+(ZrO_2+Y_2O_3) ceramic coating have a good heat insulation effect at 800℃ for heat insulation temperature difference reaches 54℃, which increases the operating temperature and service life of refractory steel.展开更多
Intermetallic aluminide compounds possess several potential advantages compared to alloyed steels,like enhanced oxidation resistance,lower density and the omittance of critical raw materials.Iron aluminides,compared t...Intermetallic aluminide compounds possess several potential advantages compared to alloyed steels,like enhanced oxidation resistance,lower density and the omittance of critical raw materials.Iron aluminides,compared to other transition metal-aluminides of TM_(3)-Al type,although having a higher density compared to titan-aluminides,have a lower density compared to nickel-aluminides,but also a higher ductility than both alternatives,making this material potentially effective in ballistic protection application.Density-wise,this material may be a worthy alternative to armour steels,which was the aim of this study.Two materials,Fe_(3)Al intermetallic compound(F3A-C)and Armox 500 armour steel were ballistically tested against tungsten-carbide(WC)armour-piercing ammunition,in accordance with STANAG 4569.After ballistic testing,microhardness and metallographic testing were performed,revealing differences in strain hardening,crack propagation mode and exit hole morphology.F3A-C ballistic resistance is similar to that of armour steel,in spite of the lower tensile and impact mechanical properties,relying on a considerably higher strain hardening rate,thermal properties and a lower density.展开更多
The corrosion resistance of NiCrAl+（ZrO2+Y2O3）thermal barrier coating, formed with the plasma spraying technique, on the 18[CD*2]8 steel surface was investigated. The phase structure and morphology of the coating we...The corrosion resistance of NiCrAl+（ZrO2+Y2O3）thermal barrier coating, formed with the plasma spraying technique, on the 18[CD*2]8 steel surface was investigated. The phase structure and morphology of the coating were analyzed by means of X-ray diffraction（XRD） and scanning electron microscopy（SEM）. The electrochemical corrosion behavior of the coating in 1.0mol/L H2SO4 solution was studied by using electrochemical measurement methods. The results show that the gradient plasma spraying coating is composed of the NiCrAlY primer coating and the （ZrO2+Y2O3 ） top coating, and the coating thickness is 360μm. The microhardness of coating reaches 1100HV. The corrosion resistance of the plasma sprayed coating of the 18[CD*2]8 steel surface is about 5 times as great as that of the original pattern. The corrosion resistance of the coating is enhanced notably.展开更多
Corrosive failure is frequently found in petrochemical pipelines which may lead to the leakage of the pipes and even the shutdown of the system. However, the corrosion mechanism is still not well understood due to the...Corrosive failure is frequently found in petrochemical pipelines which may lead to the leakage of the pipes and even the shutdown of the system. However, the corrosion mechanism is still not well understood due to the complex service environment, e.g. the corrosive fluids and the long term operation at higher temperature. The corrosion behaviour of a petrochemical pipe elbow was evaluated via visual examination and microanalysis with optical microscope and scanning electron microscope(SEM) together with energy dispersive analysis X-ray(EDAX). The corresponding corrosion mechanisms, the combination of grain boundary attach and the crevice attach together with the flow-accelerated corrosion, were proposed consequently.展开更多
Organic semiconductor materials have shown unique advantages in the development of optoelectronic devices due to their ease of preparation,low cost,lightweight,and flexibility.In this work,we explored the application ...Organic semiconductor materials have shown unique advantages in the development of optoelectronic devices due to their ease of preparation,low cost,lightweight,and flexibility.In this work,we explored the application of the organic semiconductor Y6-1O single crystal in photodetection devices.Firstly,Y6-1O single crystal material was prepared on a silicon substrate using solution droplet casting method.The optical properties of Y6-1O material were characterized by polarized optical microscopy,fluorescence spectroscopy,etc.,confirming its highly single crystalline performance and emission properties in the near-infrared region.Phototransistors based on Y6-1O materials with different thicknesses were then fabricated and tested.It was found that the devices exhibited good visible to near-infrared photoresponse,with the maximum photoresponse in the near-infrared region at 785 nm.The photocurrent on/off ratio reaches 10^(2),and photoresponsivity reaches 16 mA/W.It was also found that the spectral response of the device could be regulated by gate voltage as well as the material thickness,providing important conditions for optimizing the performance of near-infrared photodetectors.This study not only demonstrates the excellent performance of organic phototransistors based on Y6-1O single crystal material in near-infrared detection but also provides new ideas and directions for the future development of infrared detectors.展开更多
It is well known that the morphologies of the α’ martensite formed from the γ phase in ferrous alloys are classified into five types of lath, butterfly, （225）A type plate,lenticular and thin-plate. Among those α...It is well known that the morphologies of the α’ martensite formed from the γ phase in ferrous alloys are classified into five types of lath, butterfly, （225）A type plate,lenticular and thin-plate. Among those α’ martensites, only the thin-plate martensite,which is characterized by containing a high density of transformation twins, has a potential of exhibiting a perfect shape memory （SM） effect.Recently the present authors found in Fe-Ni-Si alloys that the thin-plate martensite is formed by the introduction of fine and coherent γ’-（Ni,Fe）3Si particles with a L12 ordered structure in the austenite matrix due to ausaging. In the present study, the SM properties of the ausaged Fe-Ni-Si alloys with the thin-plate martensite are investigated by a conventional bending-test. The effects of the addition of Co to the Fe-Ni-Si alloys on the martensitic transformation and the SM properties are also investigated. It is shown that while the ausaged Fe-Ni-Si ternary alloys exhibit an imperfect SM effect due to reverse transformation from stress-induced thin-plate martensite to austenite, the SM properties are improved by the addition of Co. An almost perfect SM effect is confirmed in the Fe-Ni-Si-Co alloys by heating to 1 100 ℃ after deformation at -196 ℃.展开更多
Recently, minimally invasive surgeries using guide-wire, catheter, stent etc. have spread rapidly as the diagnosis and the medical treatment for a cancer, a disease in a circulatory organ etc. Currently, further maneu...Recently, minimally invasive surgeries using guide-wire, catheter, stent etc. have spread rapidly as the diagnosis and the medical treatment for a cancer, a disease in a circulatory organ etc. Currently, further maneuverability and functionability of those devices are strongly desired in order to be used widely and safely. Although Ti-Ni shape memory alloys have been used in medical devices such orthodontic wire, guide-wire, it has been suspected that Ni is allergenic and carcinogenic to the human body. Thus the development of Ni-free shape memory alloys has been strongly required. Recently, several Ni-free beta-titanium alloys such as Ti-Mo-Al, Ti-Mo-Ga, Ti-Nb-Al have been developed as new-type shape memory alloys. We have been studying Ti-Mo based beta-titanium alloys and Ti-Mo-Sn alloy has constantly super elasticity of 3%.The purpose of present study is to propose the micro catheter with thin wall and high flexibility using To-Mo-Sn alloys tube on the basis of its mechanical properties.展开更多
文摘Two-phase equilibria between the ferromagnetic fcc and the paramagnetic fcc phase from 800 ℃ to 900 ℃ in the Co-rich region have been detected by the diffusion couple technique. Two phase separation region of the fcc has been confirmed along the Curie temperature.The phase equilibria including the present results and the thermodynamic data of the Co-Cr system reported in the literature were analyzed on the basis of the thermodynamic evaluation. A set of thermodynamic values for the liquid, fcc, hcp, bcc, sigma phases was obtained. The calculated phase equilibria were in good agreement with most of the experimental data.
文摘Tank Cascade Systems(TCS)are the back bone of the dry zone prosperity in Sri Lanka and supply water throughout the year to agricultural lands since the 2nd century BC.The main aim of this study was to understand the nutrient dynamics of small TCS and find out evidence for the sustainability of the system for thousands of years.Malagane tank cascade in the Deduru Oya Basin(the 5th largest river basin
文摘On December 26,2004,the Indian Ocean tsunami waves hit Sri Lanka resulting in the devastation of the coastal aquifers from saltwater contamination.In an attempt to speed up the cleaning process of the contaminated water in wells,large-scale and intensive campaigns went into cleaning and rehabilitating wells through pumping out saline water(physical cleansing). However,it was unclear whether these attempts improved the well-water quality,especially in terms of salinity due to density driven flow and solute transport phenomenon.Changes in water quality of a sand aquifer on the east coast of Sri Lanka owing to the December 26,2004 tsunami and
基金supported by the National High Technology Development Program of China (No. 2003AA302420)the National Major Basic Research Project (No. GT20000264-06) of MOST, China
文摘A series of positive electrodes for Ni/MH battery were fabricated by addition of CoO.The morphology and microstructure of the electrodes were examined by SEM and EDS, and electrochemical behavior was investigated in three-compartment appliances at room temperature.The electrochemical performance of the positive electrodes with CoO was improved. Under the same charge-discharge cycle, the electrodes with CoO showed higher specific capacity, lower charge mean voltage and higher discharge mean voltage. But ...
文摘A nanocomposite of manganese dioxide coated manganese hexacyanoferrate was synthesized by a facile co-precipitation method and tested as active electrode material for an electrochemical supercapacitor. A way called "Deep electro-oxidation" was used to generate manganese dioxide coated layer for stabilizing the electrode material. The structure and ingredient of the resulting MnHCF/MnO2 composites were characterized by scanning electron microscopy, transmission electron microscopy, X-ray diffraction, and X-ray Photoelectron Spectroscopy. Electrochemical testing showed a capacitance of 225.6 F/g at a sweep rate of 5 mV/s within a voltage range of 1.3 V, and high energy density of 37.2 Wh/kg at a current density of 0.5 A/g in galvanostatic charge/discharge cycling. It is suggested that the two different components, manganese hexacyanoferrate core and manganese dioxide shell, lead to an integrated electrochemical behavior, and an enhanced capacitor. The electrochemical testing and corresponding XPS analysis also demonstrated that the manganese coordinated by cyanide groups via nitrogen atoms in MnHCF did not get involved in the charge storage process during potential cycles.
文摘NiCrAlY+(ZrO_2+Y_2O_3)thermal barrier coating was prepared on the surface of refractory steel 1Cr18Ni9Ti with plasma spraying technique. The phases and microstructure of the thermal barrier coating were determined by scanning electron microscopy(SEM) and X-ray diffraction(XRD). The results show that the bonding between thermal barrier coating and substrate is sound. The surface hardness of 1Cr18Ni9Ti reaches up to 1000 HV, but that of substrate is only 300HV. The patterns sprayed with CoNiCrAlY+(ZrO_2+Y_2O_3) ceramic coating have a good heat insulation effect at 800℃ for heat insulation temperature difference reaches 54℃, which increases the operating temperature and service life of refractory steel.
基金support by the project entitled"Interdisciplinarity in Materials Science and Joining Technologies"from the Department of Production Engineering,Faculty of Technical Sciences Novi Sad,Serbia。
文摘Intermetallic aluminide compounds possess several potential advantages compared to alloyed steels,like enhanced oxidation resistance,lower density and the omittance of critical raw materials.Iron aluminides,compared to other transition metal-aluminides of TM_(3)-Al type,although having a higher density compared to titan-aluminides,have a lower density compared to nickel-aluminides,but also a higher ductility than both alternatives,making this material potentially effective in ballistic protection application.Density-wise,this material may be a worthy alternative to armour steels,which was the aim of this study.Two materials,Fe_(3)Al intermetallic compound(F3A-C)and Armox 500 armour steel were ballistically tested against tungsten-carbide(WC)armour-piercing ammunition,in accordance with STANAG 4569.After ballistic testing,microhardness and metallographic testing were performed,revealing differences in strain hardening,crack propagation mode and exit hole morphology.F3A-C ballistic resistance is similar to that of armour steel,in spite of the lower tensile and impact mechanical properties,relying on a considerably higher strain hardening rate,thermal properties and a lower density.
文摘The corrosion resistance of NiCrAl+（ZrO2+Y2O3）thermal barrier coating, formed with the plasma spraying technique, on the 18[CD*2]8 steel surface was investigated. The phase structure and morphology of the coating were analyzed by means of X-ray diffraction（XRD） and scanning electron microscopy（SEM）. The electrochemical corrosion behavior of the coating in 1.0mol/L H2SO4 solution was studied by using electrochemical measurement methods. The results show that the gradient plasma spraying coating is composed of the NiCrAlY primer coating and the （ZrO2+Y2O3 ） top coating, and the coating thickness is 360μm. The microhardness of coating reaches 1100HV. The corrosion resistance of the plasma sprayed coating of the 18[CD*2]8 steel surface is about 5 times as great as that of the original pattern. The corrosion resistance of the coating is enhanced notably.
文摘Corrosive failure is frequently found in petrochemical pipelines which may lead to the leakage of the pipes and even the shutdown of the system. However, the corrosion mechanism is still not well understood due to the complex service environment, e.g. the corrosive fluids and the long term operation at higher temperature. The corrosion behaviour of a petrochemical pipe elbow was evaluated via visual examination and microanalysis with optical microscope and scanning electron microscope(SEM) together with energy dispersive analysis X-ray(EDAX). The corresponding corrosion mechanisms, the combination of grain boundary attach and the crevice attach together with the flow-accelerated corrosion, were proposed consequently.
基金Supported by the National Key Research and Development Program of China(2021YFB2012601)National Natural Science Foundation of China(12204109)+1 种基金Science and Technology Innovation Plan of Shanghai Science and Technology Commission(21JC1400200)Higher Education Indus⁃try Support Program of Gansu Province(2022CYZC-06)。
文摘Organic semiconductor materials have shown unique advantages in the development of optoelectronic devices due to their ease of preparation,low cost,lightweight,and flexibility.In this work,we explored the application of the organic semiconductor Y6-1O single crystal in photodetection devices.Firstly,Y6-1O single crystal material was prepared on a silicon substrate using solution droplet casting method.The optical properties of Y6-1O material were characterized by polarized optical microscopy,fluorescence spectroscopy,etc.,confirming its highly single crystalline performance and emission properties in the near-infrared region.Phototransistors based on Y6-1O materials with different thicknesses were then fabricated and tested.It was found that the devices exhibited good visible to near-infrared photoresponse,with the maximum photoresponse in the near-infrared region at 785 nm.The photocurrent on/off ratio reaches 10^(2),and photoresponsivity reaches 16 mA/W.It was also found that the spectral response of the device could be regulated by gate voltage as well as the material thickness,providing important conditions for optimizing the performance of near-infrared photodetectors.This study not only demonstrates the excellent performance of organic phototransistors based on Y6-1O single crystal material in near-infrared detection but also provides new ideas and directions for the future development of infrared detectors.
文摘It is well known that the morphologies of the α’ martensite formed from the γ phase in ferrous alloys are classified into five types of lath, butterfly, （225）A type plate,lenticular and thin-plate. Among those α’ martensites, only the thin-plate martensite,which is characterized by containing a high density of transformation twins, has a potential of exhibiting a perfect shape memory （SM） effect.Recently the present authors found in Fe-Ni-Si alloys that the thin-plate martensite is formed by the introduction of fine and coherent γ’-（Ni,Fe）3Si particles with a L12 ordered structure in the austenite matrix due to ausaging. In the present study, the SM properties of the ausaged Fe-Ni-Si alloys with the thin-plate martensite are investigated by a conventional bending-test. The effects of the addition of Co to the Fe-Ni-Si alloys on the martensitic transformation and the SM properties are also investigated. It is shown that while the ausaged Fe-Ni-Si ternary alloys exhibit an imperfect SM effect due to reverse transformation from stress-induced thin-plate martensite to austenite, the SM properties are improved by the addition of Co. An almost perfect SM effect is confirmed in the Fe-Ni-Si-Co alloys by heating to 1 100 ℃ after deformation at -196 ℃.
文摘Recently, minimally invasive surgeries using guide-wire, catheter, stent etc. have spread rapidly as the diagnosis and the medical treatment for a cancer, a disease in a circulatory organ etc. Currently, further maneuverability and functionability of those devices are strongly desired in order to be used widely and safely. Although Ti-Ni shape memory alloys have been used in medical devices such orthodontic wire, guide-wire, it has been suspected that Ni is allergenic and carcinogenic to the human body. Thus the development of Ni-free shape memory alloys has been strongly required. Recently, several Ni-free beta-titanium alloys such as Ti-Mo-Al, Ti-Mo-Ga, Ti-Nb-Al have been developed as new-type shape memory alloys. We have been studying Ti-Mo based beta-titanium alloys and Ti-Mo-Sn alloy has constantly super elasticity of 3%.The purpose of present study is to propose the micro catheter with thin wall and high flexibility using To-Mo-Sn alloys tube on the basis of its mechanical properties.
