This study aims to explore the effect of project-based teaching methods on improving students’ abilities in normal universities. This study delves into the practice teaching system based on ability training implement...This study aims to explore the effect of project-based teaching methods on improving students’ abilities in normal universities. This study delves into the practice teaching system based on ability training implemented in normal universities, examining the application of this teaching model in teacher education and the potential challenges it may encounter. Our case study reveals that the Project-Based Learning (PBL) approach can effectively transform students from passive recipients of knowledge into active problem solvers, thereby enhancing their critical thinking, problem-solving, teamwork, and communication skills. However, challenges do exist, including ensuring active participation from all students, providing equal opportunities for each student to develop and showcase their abilities, and completing complex projects within a limited timeframe. Therefore, teachers may need to adjust their teaching strategies, and schools need to provide more resources and support. These adjustments can help the practice teaching system based on ability training better serve teacher education and offer students a higher-quality educational experience.展开更多
This paper is aimed at studying the effect of reading-based writing instruction on the improvement of senior three students’writing capability.By analyzing students’reading materials from the sample test papers,stud...This paper is aimed at studying the effect of reading-based writing instruction on the improvement of senior three students’writing capability.By analyzing students’reading materials from the sample test papers,students are able to notice the distinctive characteristics of the target language ranging from words,expressions,sentence structures and paragraph structures,which is beneficial to students’writing.展开更多
The granule shape and crystal structure of the the ceria-based rare earth oxide which were roasted at 600~1050 ℃ for 2~6 h and then cooled in furnace, cooled out of furnace or cooled in water were studied by means ...The granule shape and crystal structure of the the ceria-based rare earth oxide which were roasted at 600~1050 ℃ for 2~6 h and then cooled in furnace, cooled out of furnace or cooled in water were studied by means of XRD and SEM. The results revealed that the rich cerium rare earth carbonate could be changed into the rare earth oxide which was a kind of sandwich made of globose granule whose diameter was between 0.5~3.0 μm after being roasted in 900 ℃ for 2 h. This kind of crystal lattice in rare earth oxide belonged to face-centered cubic lattice and its space between crystal surface {111} and {200} (viz. L111 and L200) would enlarge as the roasting temperature increasing. With increasing roasting temperature, L111 would rise straightly upward, and L200 would rise straightly upward when roasting time was 2~4 h but changed little when roasting time was 4~6 h. The glass-polishing experiments found that the polishing ability of the ceria-based rare earth oxide was the best as L111 was 43~53 nm and the L200 was 43~56 nm.展开更多
A study for further improving the suspension rate of alcohol-based coatings using a new nano-dispersing agent has been presented in this paper. The results of experiments show that the new nano-dispersing agent should...A study for further improving the suspension rate of alcohol-based coatings using a new nano-dispersing agent has been presented in this paper. The results of experiments show that the new nano-dispersing agent should be used in combination with organic auxiliary agent which significantly increases the suspension effect of alcohol-based coatings. By the methods, the suspension rates of 99%, 98%, 96% and 94% can be achieved at 2h, 2h, 48h and 72h, respectively. These alcohol-based coatings have characters of higher strength, lower gas evolution, better brush ability and no blister after ignition.展开更多
This paper describes the development of a knowledgebased system (KBS) for determining whether or not, and under what conditions, a bank Ioan officer should grant a business loan to a company. The prototype system deve...This paper describes the development of a knowledgebased system (KBS) for determining whether or not, and under what conditions, a bank Ioan officer should grant a business loan to a company. The prototype system developed focuses on what is bank loans risks management, how to prevent risk by the analysis of the ability of paying back loans. The paper makes the structural analysis involved in the system's decision situation, the structured situation diagram or model, dependency diagram and the document needed by the KBS prototype system thus are developed. Through testing the samples from loan business, the quality for the analysis of the ability of paying back loans can be effectively evaluated by the KBS prototype system.展开更多
Ribbons of amorphous Cu-Ti-Ni alloys were prepared by the melt spinning method. The amorphous structure of these ribbons was confirmed by X-ray diffractametry and transmission electron microscopy. The effect of Ni on ...Ribbons of amorphous Cu-Ti-Ni alloys were prepared by the melt spinning method. The amorphous structure of these ribbons was confirmed by X-ray diffractametry and transmission electron microscopy. The effect of Ni on the glass-forming ability of Cu-Ti-based alloys was studied by differential scanning calorimetry(DSC). It is found that the supercooled liquid region, ?Tx value shows the maximum value of 61℃ at x=10 in the Cu50Ti50?xNix (x=0, 5, 10, 15 mole fraction, %) system. And the reduced glass transition temperature, Trg, is smaller than 0.45. The glass forming ability(GFA) of Cu-Ti alloy is not effectively promoted by Ni addition.展开更多
The paper viewed the current problem that state-owned enterprises in northeast industry base hadn't technologies of their own intellectual property right, whose sources mainly depended on imitation and introduction f...The paper viewed the current problem that state-owned enterprises in northeast industry base hadn't technologies of their own intellectual property right, whose sources mainly depended on imitation and introduction from abroad. Operational evaluation method and index criteria system of enterprises technology innovation ability were put forward in this paper, different enterprises may revise the model according to their actual situations to evaluate the enterprise technological innovation ability scientifically and quickly. The findings will be helpful to correlative departments to formulate the related policies and also has important theoretical and practical value in technological innovation project of enterprise.展开更多
The traditional teaching approach is teacher-oriented,giving priority to grammar and lexical usage and neglecting the development of students’linguistic ability.The task-based approach is based on tasks and its promi...The traditional teaching approach is teacher-oriented,giving priority to grammar and lexical usage and neglecting the development of students’linguistic ability.The task-based approach is based on tasks and its prominent feature is"learning by doing and learning by using".By accomplishing tasks in target language,students can obtain linguistic knowledge and improve linguistic ability.This thesis is based on task-based approach,referring to English compulsory textbooks in senior middle school,exploring the application of task-based approach in intensive reading classes and providing case studies.展开更多
The formation of bulk metallic glasses(BMGs) in the ternary Zr(56) Co(28-x)Al(16) and quaternary Zr(56) Co(28-x)CuxAl16(x=2, 4, 5, 6, 7, mole fraction, %) glassy alloys was investigated via the copper mo...The formation of bulk metallic glasses(BMGs) in the ternary Zr(56) Co(28-x)Al(16) and quaternary Zr(56) Co(28-x)CuxAl16(x=2, 4, 5, 6, 7, mole fraction, %) glassy alloys was investigated via the copper mold suction casting method. The main purpose of this work was to locate the optimal BMG-forming composition for the quaternary Zr Co(Cu)Al alloys and to improve the plasticity of the parent alloy. The X-ray diffractometry(XRD), transmission electron microscopy(TEM) and differential scanning calorimetry(DSC) were used to investigate the glassy alloys structure and their glass forming ability(GFA). In addition, the compression test, microhardness, nano-indentation and scanning electron microscopy(SEM) were utilized to discuss the possible mechanisms involved in the enhanced plasticity achievement. The highest GFA among Cu-containing alloys was found for the Zr(56) Co(22) Cu6 Al(16) alloy, which was similar to that of the base alloy. Furthermore, the plasticity of the base alloy increased significantly from 3.3% to 6% for the Zr(56) Co(22) Cu)6 Al(16) BMG. The variations in the plasticity and GFA of the alloys were discussed by considering the positive heat of mixing within Cu and Co elements.展开更多
A 330-500 GHz zero-biased broadband monolithic integrated tripler is reported. The measured results show that the maximum efficiency and the maximum output power are 2% and 194μW at 348 GHz. The saturation characteri...A 330-500 GHz zero-biased broadband monolithic integrated tripler is reported. The measured results show that the maximum efficiency and the maximum output power are 2% and 194μW at 348 GHz. The saturation characteristic test shows that the output i dB compression point is about -8.5 dBm at 334 GHz and the maximum efficiency is obtained at the point, which is slightly below the 1 dB compression point. Compared with the conventional hybrid integrated circuit, a major advantage of the monolithic integrated circuit is the significant improvement of reliability and consistency. In this work, a terahertz monolithic frequency multiplier at this band is designed and fabricated.展开更多
In recent years,Kaifeng Meteorological Bureau and Kaifeng Municipal Meteorological Society seriously think how to strengthen the construction of science popularization base,and take below measures improving the influe...In recent years,Kaifeng Meteorological Bureau and Kaifeng Municipal Meteorological Society seriously think how to strengthen the construction of science popularization base,and take below measures improving the influence of " national science popularization education base" and further increasing the propaganda of meteorological popular science knowledge. Firstly,launching periodical meteorological science popularization into campus,village and community,and holding meteorological science forum; secondly,cooperating with municipal science association and Science and Technology Bureau,and jointly issuing the related documents of carrying out the propaganda of meteorological science popularization;thirdly,co-constructing campus weather station and meteorological science popularization demonstration community; fourthly,setting up special meteorological science lecture and report meeting; fifthly,integrating meteorological science with studies of Chinese ancient civilization based on innovation. In the form of recreation and loved by the masses,the propaganda of meteorological popular science knowledge is done well,and people recognizing,understanding,grasping and applying meteorological science is improved,thereby reaching the target of decreasing the damages of meteorological disaster to social economy and human life and property.展开更多
Mg86.33Ni13.67-xYx(x=0, 1, 3, 6, 10) amorphous alloys were obtained by single-roller melt-spinning technique and the effect of Y addition on the glass forming ability(GFA), crystallization and micro-hardness of Mg-Ni ...Mg86.33Ni13.67-xYx(x=0, 1, 3, 6, 10) amorphous alloys were obtained by single-roller melt-spinning technique and the effect of Y addition on the glass forming ability(GFA), crystallization and micro-hardness of Mg-Ni alloys were studied. The results show that the GFA of Mg86.33Ni13.67-xYx(x=0, 1, 3, 6, 10) is improved successfully with the Y addition. The highest GFA appeares at x=6, while the reduced glass transition temperature (Trg) is 0.5225 and the supercooled liquid region(ΔTx) is 42.06 K; the position of the main diffraction halo is different for the alloys, and the maximum of the main diffraction halo of alloys with x=0, 1, 3 corresponds to the main peaks of a metastable fcc-Mg6Ni or fcc-Mg6Ni + Ni-Y intermetallic phases, and for the alloys with x=6, 10, it corresponds to Mg-Y and Ni-Y intermetallic phases; the micro-hardness of the alloys is improved with Y additions, and the highest micro-hardness is obtained at x=6 at.%, which is 960 MPa.展开更多
It is found that strong basic oxides including Li2O,Na2O,K2O and BaO,which are used to replace a part of CaO in CaO-based fluxes,can lower the melting point and the viscosity and enhance the dephosphorizing ability. T...It is found that strong basic oxides including Li2O,Na2O,K2O and BaO,which are used to replace a part of CaO in CaO-based fluxes,can lower the melting point and the viscosity and enhance the dephosphorizing ability. The mechanism was analysed and the addition of Li2O to CaO based fluxes was recommended.展开更多
After substituting partial Cu and Mg with Zn or Al elements for Mg65Cu25Y10 alloy,respectively,the metallic glass plate samples with thickness of 2-3 mm were prepared by water-quenching,their respective glass-forming ...After substituting partial Cu and Mg with Zn or Al elements for Mg65Cu25Y10 alloy,respectively,the metallic glass plate samples with thickness of 2-3 mm were prepared by water-quenching,their respective glass-forming ability and thermal stability were studied by using differential thermal analysis(DTA) and X-ray diffraction(XRD). Using Kissinger equation,the activation energies of crystallization of these metallic glasses heated with a constant rate were calculated. The results show that Al element is greatly harmful to the glass-forming ability of Mg-Cu-Y alloys and cannot acquire bulk amorphous alloys;nevertheless,the effect of Zn element addition is indeterminate for various components. The magnitudes of thermal stability are also revealed.展开更多
The formation and thermal stabilities of Cu46.25Zr46.25xAl7.5Erx (x=0 to 8) bulk metallic glasses (BMGs) were investigated. The addition of a small amount of Er (2at%) for replacing Zr effectively improves the glass-f...The formation and thermal stabilities of Cu46.25Zr46.25xAl7.5Erx (x=0 to 8) bulk metallic glasses (BMGs) were investigated. The addition of a small amount of Er (2at%) for replacing Zr effectively improves the glass-forming ability of Cu46.25Zr46.25Al7.5 alloy, and the glassy rod with a diameter of at least 12 mm can be formed. The glass transition temperature (Tg), temperature interval of su- percooled liquid region △Tx (=Tx-Tg), and reduced glass transition temperature Trg (=Tg/Tl) of Cu46.25Zr44.25Al7.5Er2 glassy alloy are 699 K, 62 K and 0.607, respectively.展开更多
The unusual glass-forming ability(GFA) of the Zr48Cu36Ag8Al8 alloy and the high ductility of the Zr48Cu36Ag8Al8 metallic glass-matrix composites containing Ta powder were reported.The bulk metallic glass rod with a ...The unusual glass-forming ability(GFA) of the Zr48Cu36Ag8Al8 alloy and the high ductility of the Zr48Cu36Ag8Al8 metallic glass-matrix composites containing Ta powder were reported.The bulk metallic glass rod with a diameter of 25 mm was successfully synthesized using copper mold casting for the Zr48Cu36Ag8Al8 alloy.High GFA of this alloy was found to be related to a large supercooled liquid region and a quaternary eutectic point with low melting temperature.The bulk metallic glass matrix composites were prepared by introducing extra Ta particles into the Zr48Cu36Ag8Al8 melt.The composites consist of Ta particles homogenously distributed in the Zr48Cu36Ag8Al8 metallic glass matrix.The optimum content of Ta powder is 10at%for the composite with the highest plasticity,which shows a plastic strain of 31%.展开更多
The effect of niobium on glass-formation ability and soft magnetic properties were studied in Fe-Gd-B glassy alloys. The glassy alloys exhibited high glass-formation ability when the element of Nb was added. Bulk glas...The effect of niobium on glass-formation ability and soft magnetic properties were studied in Fe-Gd-B glassy alloys. The glassy alloys exhibited high glass-formation ability when the element of Nb was added. Bulk glassy rod (Fe0.87Co0.13)68.5Gd3.5Nb3B25 with a diameter up to 3 mm was produced by copper mold casting. The size of the atom might play an important role in increasing glass-formation ability. The coercive force of glassy (Fe0.87Co0.13)71.5.xGd3.sNbxB25 (x=1.2, 1.5, 2, 2.5, 3, 4) alloys decreased after the addition of niobium element and was in the range of 1.5-2.9 A/m. The permeability spectrum of (Fe0.87Co0.13)70.3Gd3.5Nb1.5B25 glassy ribbon showed that the relaxation frequency (f0) was 6.1 MHz.展开更多
文摘This study aims to explore the effect of project-based teaching methods on improving students’ abilities in normal universities. This study delves into the practice teaching system based on ability training implemented in normal universities, examining the application of this teaching model in teacher education and the potential challenges it may encounter. Our case study reveals that the Project-Based Learning (PBL) approach can effectively transform students from passive recipients of knowledge into active problem solvers, thereby enhancing their critical thinking, problem-solving, teamwork, and communication skills. However, challenges do exist, including ensuring active participation from all students, providing equal opportunities for each student to develop and showcase their abilities, and completing complex projects within a limited timeframe. Therefore, teachers may need to adjust their teaching strategies, and schools need to provide more resources and support. These adjustments can help the practice teaching system based on ability training better serve teacher education and offer students a higher-quality educational experience.
文摘This paper is aimed at studying the effect of reading-based writing instruction on the improvement of senior three students’writing capability.By analyzing students’reading materials from the sample test papers,students are able to notice the distinctive characteristics of the target language ranging from words,expressions,sentence structures and paragraph structures,which is beneficial to students’writing.
文摘The granule shape and crystal structure of the the ceria-based rare earth oxide which were roasted at 600~1050 ℃ for 2~6 h and then cooled in furnace, cooled out of furnace or cooled in water were studied by means of XRD and SEM. The results revealed that the rich cerium rare earth carbonate could be changed into the rare earth oxide which was a kind of sandwich made of globose granule whose diameter was between 0.5~3.0 μm after being roasted in 900 ℃ for 2 h. This kind of crystal lattice in rare earth oxide belonged to face-centered cubic lattice and its space between crystal surface {111} and {200} (viz. L111 and L200) would enlarge as the roasting temperature increasing. With increasing roasting temperature, L111 would rise straightly upward, and L200 would rise straightly upward when roasting time was 2~4 h but changed little when roasting time was 4~6 h. The glass-polishing experiments found that the polishing ability of the ceria-based rare earth oxide was the best as L111 was 43~53 nm and the L200 was 43~56 nm.
文摘A study for further improving the suspension rate of alcohol-based coatings using a new nano-dispersing agent has been presented in this paper. The results of experiments show that the new nano-dispersing agent should be used in combination with organic auxiliary agent which significantly increases the suspension effect of alcohol-based coatings. By the methods, the suspension rates of 99%, 98%, 96% and 94% can be achieved at 2h, 2h, 48h and 72h, respectively. These alcohol-based coatings have characters of higher strength, lower gas evolution, better brush ability and no blister after ignition.
基金Supported by the National Science Foundation of China(No.7977086)
文摘This paper describes the development of a knowledgebased system (KBS) for determining whether or not, and under what conditions, a bank Ioan officer should grant a business loan to a company. The prototype system developed focuses on what is bank loans risks management, how to prevent risk by the analysis of the ability of paying back loans. The paper makes the structural analysis involved in the system's decision situation, the structured situation diagram or model, dependency diagram and the document needed by the KBS prototype system thus are developed. Through testing the samples from loan business, the quality for the analysis of the ability of paying back loans can be effectively evaluated by the KBS prototype system.
基金Project(50471052) supported by the National Natural Science Foundation of China Project(Z2004F02) supported by the Natural Science Foundation of Shandong Province, China Project(2005422024) supported by the Specialized Research Fund for the Doctoral Program of Higher Education
文摘Ribbons of amorphous Cu-Ti-Ni alloys were prepared by the melt spinning method. The amorphous structure of these ribbons was confirmed by X-ray diffractametry and transmission electron microscopy. The effect of Ni on the glass-forming ability of Cu-Ti-based alloys was studied by differential scanning calorimetry(DSC). It is found that the supercooled liquid region, ?Tx value shows the maximum value of 61℃ at x=10 in the Cu50Ti50?xNix (x=0, 5, 10, 15 mole fraction, %) system. And the reduced glass transition temperature, Trg, is smaller than 0.45. The glass forming ability(GFA) of Cu-Ti alloy is not effectively promoted by Ni addition.
文摘The paper viewed the current problem that state-owned enterprises in northeast industry base hadn't technologies of their own intellectual property right, whose sources mainly depended on imitation and introduction from abroad. Operational evaluation method and index criteria system of enterprises technology innovation ability were put forward in this paper, different enterprises may revise the model according to their actual situations to evaluate the enterprise technological innovation ability scientifically and quickly. The findings will be helpful to correlative departments to formulate the related policies and also has important theoretical and practical value in technological innovation project of enterprise.
文摘The traditional teaching approach is teacher-oriented,giving priority to grammar and lexical usage and neglecting the development of students’linguistic ability.The task-based approach is based on tasks and its prominent feature is"learning by doing and learning by using".By accomplishing tasks in target language,students can obtain linguistic knowledge and improve linguistic ability.This thesis is based on task-based approach,referring to English compulsory textbooks in senior middle school,exploring the application of task-based approach in intensive reading classes and providing case studies.
基金Iran University of Science and Technology for the financial support
文摘The formation of bulk metallic glasses(BMGs) in the ternary Zr(56) Co(28-x)Al(16) and quaternary Zr(56) Co(28-x)CuxAl16(x=2, 4, 5, 6, 7, mole fraction, %) glassy alloys was investigated via the copper mold suction casting method. The main purpose of this work was to locate the optimal BMG-forming composition for the quaternary Zr Co(Cu)Al alloys and to improve the plasticity of the parent alloy. The X-ray diffractometry(XRD), transmission electron microscopy(TEM) and differential scanning calorimetry(DSC) were used to investigate the glassy alloys structure and their glass forming ability(GFA). In addition, the compression test, microhardness, nano-indentation and scanning electron microscopy(SEM) were utilized to discuss the possible mechanisms involved in the enhanced plasticity achievement. The highest GFA among Cu-containing alloys was found for the Zr(56) Co(22) Cu6 Al(16) alloy, which was similar to that of the base alloy. Furthermore, the plasticity of the base alloy increased significantly from 3.3% to 6% for the Zr(56) Co(22) Cu)6 Al(16) BMG. The variations in the plasticity and GFA of the alloys were discussed by considering the positive heat of mixing within Cu and Co elements.
基金Supported by the National High-Technology Research and Development Program of China under Grant No 2011AA010203the National Basic Research Program of China under Grant Nos 2011CB201704 and 2010CB327502the National Natural Science Foundation of China under Grant Nos 61434006 and 61106074
文摘A 330-500 GHz zero-biased broadband monolithic integrated tripler is reported. The measured results show that the maximum efficiency and the maximum output power are 2% and 194μW at 348 GHz. The saturation characteristic test shows that the output i dB compression point is about -8.5 dBm at 334 GHz and the maximum efficiency is obtained at the point, which is slightly below the 1 dB compression point. Compared with the conventional hybrid integrated circuit, a major advantage of the monolithic integrated circuit is the significant improvement of reliability and consistency. In this work, a terahertz monolithic frequency multiplier at this band is designed and fabricated.
文摘In recent years,Kaifeng Meteorological Bureau and Kaifeng Municipal Meteorological Society seriously think how to strengthen the construction of science popularization base,and take below measures improving the influence of " national science popularization education base" and further increasing the propaganda of meteorological popular science knowledge. Firstly,launching periodical meteorological science popularization into campus,village and community,and holding meteorological science forum; secondly,cooperating with municipal science association and Science and Technology Bureau,and jointly issuing the related documents of carrying out the propaganda of meteorological science popularization;thirdly,co-constructing campus weather station and meteorological science popularization demonstration community; fourthly,setting up special meteorological science lecture and report meeting; fifthly,integrating meteorological science with studies of Chinese ancient civilization based on innovation. In the form of recreation and loved by the masses,the propaganda of meteorological popular science knowledge is done well,and people recognizing,understanding,grasping and applying meteorological science is improved,thereby reaching the target of decreasing the damages of meteorological disaster to social economy and human life and property.
基金supported by the Award Fund for Outstanding Young Scientist in Shandong Province, China (No. BS2011CL004)
文摘Mg86.33Ni13.67-xYx(x=0, 1, 3, 6, 10) amorphous alloys were obtained by single-roller melt-spinning technique and the effect of Y addition on the glass forming ability(GFA), crystallization and micro-hardness of Mg-Ni alloys were studied. The results show that the GFA of Mg86.33Ni13.67-xYx(x=0, 1, 3, 6, 10) is improved successfully with the Y addition. The highest GFA appeares at x=6, while the reduced glass transition temperature (Trg) is 0.5225 and the supercooled liquid region(ΔTx) is 42.06 K; the position of the main diffraction halo is different for the alloys, and the maximum of the main diffraction halo of alloys with x=0, 1, 3 corresponds to the main peaks of a metastable fcc-Mg6Ni or fcc-Mg6Ni + Ni-Y intermetallic phases, and for the alloys with x=6, 10, it corresponds to Mg-Y and Ni-Y intermetallic phases; the micro-hardness of the alloys is improved with Y additions, and the highest micro-hardness is obtained at x=6 at.%, which is 960 MPa.
基金Item Sponsored by National Natural Science Foundation of China(59774015)
文摘It is found that strong basic oxides including Li2O,Na2O,K2O and BaO,which are used to replace a part of CaO in CaO-based fluxes,can lower the melting point and the viscosity and enhance the dephosphorizing ability. The mechanism was analysed and the addition of Li2O to CaO based fluxes was recommended.
基金Project(BK2003045) supported by the Natural Science Foundation of Jiangsu Province, China Project(03KJB430006) supported by the Natural Science Foundation of High School of Jiangsu Province
文摘After substituting partial Cu and Mg with Zn or Al elements for Mg65Cu25Y10 alloy,respectively,the metallic glass plate samples with thickness of 2-3 mm were prepared by water-quenching,their respective glass-forming ability and thermal stability were studied by using differential thermal analysis(DTA) and X-ray diffraction(XRD). Using Kissinger equation,the activation energies of crystallization of these metallic glasses heated with a constant rate were calculated. The results show that Al element is greatly harmful to the glass-forming ability of Mg-Cu-Y alloys and cannot acquire bulk amorphous alloys;nevertheless,the effect of Zn element addition is indeterminate for various components. The magnitudes of thermal stability are also revealed.
基金This work was financially supported by the National Natural Science Foundation of China (No.50225103, 50471001, and 50631010).
文摘The formation and thermal stabilities of Cu46.25Zr46.25xAl7.5Erx (x=0 to 8) bulk metallic glasses (BMGs) were investigated. The addition of a small amount of Er (2at%) for replacing Zr effectively improves the glass-forming ability of Cu46.25Zr46.25Al7.5 alloy, and the glassy rod with a diameter of at least 12 mm can be formed. The glass transition temperature (Tg), temperature interval of su- percooled liquid region △Tx (=Tx-Tg), and reduced glass transition temperature Trg (=Tg/Tl) of Cu46.25Zr44.25Al7.5Er2 glassy alloy are 699 K, 62 K and 0.607, respectively.
基金supported by Grant-In-Aid for Scientific Research(C)(No.19560689)
文摘The unusual glass-forming ability(GFA) of the Zr48Cu36Ag8Al8 alloy and the high ductility of the Zr48Cu36Ag8Al8 metallic glass-matrix composites containing Ta powder were reported.The bulk metallic glass rod with a diameter of 25 mm was successfully synthesized using copper mold casting for the Zr48Cu36Ag8Al8 alloy.High GFA of this alloy was found to be related to a large supercooled liquid region and a quaternary eutectic point with low melting temperature.The bulk metallic glass matrix composites were prepared by introducing extra Ta particles into the Zr48Cu36Ag8Al8 melt.The composites consist of Ta particles homogenously distributed in the Zr48Cu36Ag8Al8 metallic glass matrix.The optimum content of Ta powder is 10at%for the composite with the highest plasticity,which shows a plastic strain of 31%.
基金Project supported by the National Natural Science Foundation of China (50471094)
文摘The effect of niobium on glass-formation ability and soft magnetic properties were studied in Fe-Gd-B glassy alloys. The glassy alloys exhibited high glass-formation ability when the element of Nb was added. Bulk glassy rod (Fe0.87Co0.13)68.5Gd3.5Nb3B25 with a diameter up to 3 mm was produced by copper mold casting. The size of the atom might play an important role in increasing glass-formation ability. The coercive force of glassy (Fe0.87Co0.13)71.5.xGd3.sNbxB25 (x=1.2, 1.5, 2, 2.5, 3, 4) alloys decreased after the addition of niobium element and was in the range of 1.5-2.9 A/m. The permeability spectrum of (Fe0.87Co0.13)70.3Gd3.5Nb1.5B25 glassy ribbon showed that the relaxation frequency (f0) was 6.1 MHz.