The bainitic transformation in a Cu-Zn-Al-Mn alloy has been examined with TEM.The re- sults show that the stacking faults and also the bainitic midrib are found at the beginning of bainite formation in the alloy.The s...The bainitic transformation in a Cu-Zn-Al-Mn alloy has been examined with TEM.The re- sults show that the stacking faults and also the bainitic midrib are found at the beginning of bainite formation in the alloy.The stacking fault planes can pass continuously through the midrib in bainite.The growth ledges occur at the broad faces and rims of bainite.The broad and narrow faces of th ledges are parallel to the fault plane and habit plane respectively.Both their Miller indices are {110}_(B2).The moving direction of ledges is parallel to the fault plane. It may be deduced that the bainite in alloy are initially formed by shear and the process of growth are go verned by propagation o f fault planes.展开更多
A mixed-control model was developed to study the transformation character of ferrite formation by a ledge mechanism. A nu- merical two-dimensional diffusion-field model was combined to describe the evolution of the di...A mixed-control model was developed to study the transformation character of ferrite formation by a ledge mechanism. A nu- merical two-dimensional diffusion-field model was combined to describe the evolution of the diffusion field ahead of the migrating austenite/ferrite interface. The calculation results show that the bulk diffusion-controlled model leads to a deviation from experimental results under large solute supersaturation. In the mixed-control model, solute supersaturation and a parameter Z together determine the transformation character, which is quantified by the normalized concentration of carbon in austenite at the austenite/ferfite interface. By comparing with experimental data, thepre-exponential factor of interface mobility, M0, is estimated within the range from 0.10 to 0.60 mol-m·J^-1·s^-1 for the alloys with 0.1 lwt%-0.49wt% C at 700-740℃. For a certain Fe-C alloy, the trend of the transformation character relies on the magnitude of M0 as the transformation temperature decreases.展开更多
The unit cell of lanthanum chromate was constructed by calculating equivalent points. By means of calculation of the hole octahedrally surrounded by O^(2-) ions, it was considered that the sintered property of lanthan...The unit cell of lanthanum chromate was constructed by calculating equivalent points. By means of calculation of the hole octahedrally surrounded by O^(2-) ions, it was considered that the sintered property of lanthanum chromate and the stability of Cr-O octahedron might be promoted by mixing a little Ca^(2+) ions. The growth mechanism was discussed in terms of structural ledge observed by SEM, the surfaces of the structural ledges parallel to (001), (010) and (110) planes, respectively. The misfit between (110) and (001) planes is only 0.0021 on common atomic plane, and the interconnection of the structured ledge may occur during crystal growth.展开更多
The ferrite/austenite interfacial structure in lower bainite has been studied in a hypereutectoid steel by means of electron microscopy.It is found that the mobile growth ledges and superledges and their three-dimensi...The ferrite/austenite interfacial structure in lower bainite has been studied in a hypereutectoid steel by means of electron microscopy.It is found that the mobile growth ledges and superledges and their three-dimensional morphologies exist on the broad faces of ferrite plates.Structural ledges were also observed on the broad faces of lower bainite.Based on TEM observations,the viewpoint that the growth ledges can also evolve from structural ledges is proposed.These observations provide evidences to the ledge growth mechanism of lower bainite.展开更多
It was shown by the study of TEM that the fine lamellar pearlite becomes a ductile phase dur- ing cold drawing.There exist many ledges to emit dislocations at Fe_3C/Fe interface.It is one of the reasons that high dens...It was shown by the study of TEM that the fine lamellar pearlite becomes a ductile phase dur- ing cold drawing.There exist many ledges to emit dislocations at Fe_3C/Fe interface.It is one of the reasons that high density of dislocations emerges at the Fe_3C/Fe interface. Furthermore,there are some evidences to support that dislocation cuts through Fe_3C.There- fore,it is necessary to consider the contribution of cementite being sheared strengthening.展开更多
The Supreme Siviet electedCommunist Party Chief HikhailGorbachev as the new head ofState on October I to take theplace of Andrei Gromyko who hadretired a day ago.Iranian and Iraqi foreignministers resumed talks in New...The Supreme Siviet electedCommunist Party Chief HikhailGorbachev as the new head ofState on October I to take theplace of Andrei Gromyko who hadretired a day ago.Iranian and Iraqi foreignministers resumed talks in NewYork on October I.The talksremained deadlocked over theShatt-al-Arab waterway.展开更多
CHINA formally an-nounced that all 74 vol-umes of the Chinese En-cyclopedia were published by Oc-tober 1993 after 15 years of re-search.President Jiang Zeminand Premier Li Peng conveyedtheir congratulations on the com...CHINA formally an-nounced that all 74 vol-umes of the Chinese En-cyclopedia were published by Oc-tober 1993 after 15 years of re-search.President Jiang Zeminand Premier Li Peng conveyedtheir congratulations on the com-pletion of this major work andreceived all the editors In a pri-vate audience.President Jiangsaid,“The Chinese Encyclopedia in-cludes both the ancient and mod-ern,both Chinese and foreignscholarship.It embodies thegreat Chinese tradition”展开更多
英语中有些定语从句,在结构上是定语从句,但功能上却不是作定语用,而是作状语用。这种作状语用的定语从句,我们称之为状语化定语从句,相当于状语从句,在一定的上下文中可用来表示原因、结果、目的、让步、条件、时间等。如: 一、表示原...英语中有些定语从句,在结构上是定语从句,但功能上却不是作定语用,而是作状语用。这种作状语用的定语从句,我们称之为状语化定语从句,相当于状语从句,在一定的上下文中可用来表示原因、结果、目的、让步、条件、时间等。如: 一、表示原因 1.Einstein,who worked out the famous theory ofRelativity,won the Nobel Prize in 1921.(句中定语从句who…Relativity相当于原因状语从句because he worked out展开更多
Fashion industry has a complex characteristic for it spans the first, second, and third industries. In addition, the characteristic of creative industry has high value-added for its knowledge outputting, which makes t...Fashion industry has a complex characteristic for it spans the first, second, and third industries. In addition, the characteristic of creative industry has high value-added for its knowledge outputting, which makes the traditional value-added analysis based on supply chain not easy and good enough to interpret its industry value-added features. From the perspective of "products-knowledge" two-dimensional analysis,a fashion industry value chain increment model is built,by simulating the process of "product flow" and "information flow" value-added. The fashion industry value chain increment model provides an effective way for the enterprise strategy formulation and production strategy adjustment.展开更多
Covalent organic frameworks(coFs)driven photocatalytic organic transformations especially photooxidation reactions have become a fertile topic and attracted numerous research attentions.Boosting the charge generation ...Covalent organic frameworks(coFs)driven photocatalytic organic transformations especially photooxidation reactions have become a fertile topic and attracted numerous research attentions.Boosting the charge generation and transport process is the key factor for achieving high catalytic efficiencies.As one of the most effective strategies,the introduction of"heavy atoms"into the long-range ordered conjugated backbones can effectively facilitate the intersystem crossing(isc)process and hence improve the generation of active oxygens,which is beneficial for the oxidation.In this work,we designed and synthesized a benzoselenadiazole based covalent organic framework(COF)material,BSe-COF with heavy atom of selenium(Se),and a benzothiadiazole based BT-COF with isomorphic backbone for comparison.展开更多
1 Introduction A blockchain can be referred to as a distributed ledger[1].Nowadays,according to our previous work[2],the graphrelated blockchain grows efficiently in both academic studies and commercial scenarios.Grap...1 Introduction A blockchain can be referred to as a distributed ledger[1].Nowadays,according to our previous work[2],the graphrelated blockchain grows efficiently in both academic studies and commercial scenarios.Graph data,algorithms and applications can be applied in blockchain now,such as[3].展开更多
The bainitic transformation mechanism is one of the controversial issues in solid phase transformations on which sharp arguments have lasted for a long time. A lot of research work on this mechanism has been done by b...The bainitic transformation mechanism is one of the controversial issues in solid phase transformations on which sharp arguments have lasted for a long time. A lot of research work on this mechanism has been done by both the shear and diffusion schools. Results from these two schools have many differences and the viewpoints on them are different essentially as展开更多
The fine structure of bainite,the morphology and distribution of carbide in steels and the morphology of bainite in Cu-Zn-Al alloys have been investigated with TEM.The interfacial structure ledges and interfacial crys...The fine structure of bainite,the morphology and distribution of carbide in steels and the morphology of bainite in Cu-Zn-Al alloys have been investigated with TEM.The interfacial structure ledges and interfacial crystal lattice images of Cu-Zn-Al alloys have also been investigated with HREM.The addition of alloying microelements can fine the structure of bainitic ferrite markedly.The bainitic ferrite is composed of subunits or subchunks.The carbides differ in morphologies and are distributed in between laths,inside the plates and on the boundaries of subunits.There are abundant fine structures in bainitic ferrite.In the primary bainite of Cu-Zn-Al alloy there are interfacial structure ledges,the height of which is about 3 -40 nm,equal to 15-200 atomic layers.The phase transformation mechanism of bainite is discussed.展开更多
Let D be a nonsquare integer and p be an odd prime with p(?)D. The equation x^2-D=p^n, x>0, n>0 (1) is usually called the generalized Ramanujan-Nagell equation. For this equation, there are many related works wr...Let D be a nonsquare integer and p be an odd prime with p(?)D. The equation x^2-D=p^n, x>0, n>0 (1) is usually called the generalized Ramanujan-Nagell equation. For this equation, there are many related works written by Alter and Kubota, Brown, Cohen and lnkeri. In this letter, we shall prove the展开更多
The geometrical matching/mismatching of lattices overlapped in 1, 2 and 3 dimensions have been analyzed systematically by variation of lattice misfit in a large range, far beyond the limits for semicoherent interfaces...The geometrical matching/mismatching of lattices overlapped in 1, 2 and 3 dimensions have been analyzed systematically by variation of lattice misfit in a large range, far beyond the limits for semicoherent interfaces. In order to evaluate the degree of matching, the density of good matching site （GMS） between two lattices is calculated. The analysis shows that the GMS density remains approximately constant, irrespectively to the degree of lattice misfit. This constant, defined as the average GMS density, decreases exponentially with the increasing dimension of misfit. Typically, for 6 = 15%, the average GMS densities are approximately 30%, 7%, and 1.4% for 1D, 2D, and 3D lattice misfits, respectively. The GMS density deviates significantly if a CSL of small X can be defined. The relationship between the GMS distribution and O-lattice is investigated. It indicates that an abrupt increase in the GMS density in an interface parallel to a principal O-lattice plane is equivalent to a reduction of dimension of misfit. This shows the agreement between the selections of principal O-lattice planes as candidates of the preferred interfaces and the condition that interfaces with high GMS density are preferred.展开更多
文摘The bainitic transformation in a Cu-Zn-Al-Mn alloy has been examined with TEM.The re- sults show that the stacking faults and also the bainitic midrib are found at the beginning of bainite formation in the alloy.The stacking fault planes can pass continuously through the midrib in bainite.The growth ledges occur at the broad faces and rims of bainite.The broad and narrow faces of th ledges are parallel to the fault plane and habit plane respectively.Both their Miller indices are {110}_(B2).The moving direction of ledges is parallel to the fault plane. It may be deduced that the bainite in alloy are initially formed by shear and the process of growth are go verned by propagation o f fault planes.
基金supported by the National Natural Science Foundation of China (Nos.51171087 and 51071089)the Specialized Research Fund for the Doctoral Program of Higher Education (No.20070003006)
文摘A mixed-control model was developed to study the transformation character of ferrite formation by a ledge mechanism. A nu- merical two-dimensional diffusion-field model was combined to describe the evolution of the diffusion field ahead of the migrating austenite/ferrite interface. The calculation results show that the bulk diffusion-controlled model leads to a deviation from experimental results under large solute supersaturation. In the mixed-control model, solute supersaturation and a parameter Z together determine the transformation character, which is quantified by the normalized concentration of carbon in austenite at the austenite/ferfite interface. By comparing with experimental data, thepre-exponential factor of interface mobility, M0, is estimated within the range from 0.10 to 0.60 mol-m·J^-1·s^-1 for the alloys with 0.1 lwt%-0.49wt% C at 700-740℃. For a certain Fe-C alloy, the trend of the transformation character relies on the magnitude of M0 as the transformation temperature decreases.
基金Project supported by the National"863"High Technology Project (2001AA327010) and the National Natural Science Founda tion of China (50362001)
文摘The unit cell of lanthanum chromate was constructed by calculating equivalent points. By means of calculation of the hole octahedrally surrounded by O^(2-) ions, it was considered that the sintered property of lanthanum chromate and the stability of Cr-O octahedron might be promoted by mixing a little Ca^(2+) ions. The growth mechanism was discussed in terms of structural ledge observed by SEM, the surfaces of the structural ledges parallel to (001), (010) and (110) planes, respectively. The misfit between (110) and (001) planes is only 0.0021 on common atomic plane, and the interconnection of the structured ledge may occur during crystal growth.
文摘The ferrite/austenite interfacial structure in lower bainite has been studied in a hypereutectoid steel by means of electron microscopy.It is found that the mobile growth ledges and superledges and their three-dimensional morphologies exist on the broad faces of ferrite plates.Structural ledges were also observed on the broad faces of lower bainite.Based on TEM observations,the viewpoint that the growth ledges can also evolve from structural ledges is proposed.These observations provide evidences to the ledge growth mechanism of lower bainite.
文摘It was shown by the study of TEM that the fine lamellar pearlite becomes a ductile phase dur- ing cold drawing.There exist many ledges to emit dislocations at Fe_3C/Fe interface.It is one of the reasons that high density of dislocations emerges at the Fe_3C/Fe interface. Furthermore,there are some evidences to support that dislocation cuts through Fe_3C.There- fore,it is necessary to consider the contribution of cementite being sheared strengthening.
文摘The Supreme Siviet electedCommunist Party Chief HikhailGorbachev as the new head ofState on October I to take theplace of Andrei Gromyko who hadretired a day ago.Iranian and Iraqi foreignministers resumed talks in NewYork on October I.The talksremained deadlocked over theShatt-al-Arab waterway.
文摘CHINA formally an-nounced that all 74 vol-umes of the Chinese En-cyclopedia were published by Oc-tober 1993 after 15 years of re-search.President Jiang Zeminand Premier Li Peng conveyedtheir congratulations on the com-pletion of this major work andreceived all the editors In a pri-vate audience.President Jiangsaid,“The Chinese Encyclopedia in-cludes both the ancient and mod-ern,both Chinese and foreignscholarship.It embodies thegreat Chinese tradition”
文摘英语中有些定语从句,在结构上是定语从句,但功能上却不是作定语用,而是作状语用。这种作状语用的定语从句,我们称之为状语化定语从句,相当于状语从句,在一定的上下文中可用来表示原因、结果、目的、让步、条件、时间等。如: 一、表示原因 1.Einstein,who worked out the famous theory ofRelativity,won the Nobel Prize in 1921.(句中定语从句who…Relativity相当于原因状语从句because he worked out
基金Shanghai University Young Teachers Training Program,China(No.KY01X0322016010)
文摘Fashion industry has a complex characteristic for it spans the first, second, and third industries. In addition, the characteristic of creative industry has high value-added for its knowledge outputting, which makes the traditional value-added analysis based on supply chain not easy and good enough to interpret its industry value-added features. From the perspective of "products-knowledge" two-dimensional analysis,a fashion industry value chain increment model is built,by simulating the process of "product flow" and "information flow" value-added. The fashion industry value chain increment model provides an effective way for the enterprise strategy formulation and production strategy adjustment.
基金the financial support from the National Natural Science Foundation of China(Grant Nos.22371172,22201166 and 22203049)the Major Basic Research Projects of Shandong Provincial NaturalScienceFoundation(No.ZR2020ZD32)the Taishan Scholars Climbing Program of Shandong Province.
文摘Covalent organic frameworks(coFs)driven photocatalytic organic transformations especially photooxidation reactions have become a fertile topic and attracted numerous research attentions.Boosting the charge generation and transport process is the key factor for achieving high catalytic efficiencies.As one of the most effective strategies,the introduction of"heavy atoms"into the long-range ordered conjugated backbones can effectively facilitate the intersystem crossing(isc)process and hence improve the generation of active oxygens,which is beneficial for the oxidation.In this work,we designed and synthesized a benzoselenadiazole based covalent organic framework(COF)material,BSe-COF with heavy atom of selenium(Se),and a benzothiadiazole based BT-COF with isomorphic backbone for comparison.
基金supported by the Research Foundation of Huawei Cloud Computing Technologies Co.,Ltd.,China (No.TC20220104482).
文摘1 Introduction A blockchain can be referred to as a distributed ledger[1].Nowadays,according to our previous work[2],the graphrelated blockchain grows efficiently in both academic studies and commercial scenarios.Graph data,algorithms and applications can be applied in blockchain now,such as[3].
文摘The bainitic transformation mechanism is one of the controversial issues in solid phase transformations on which sharp arguments have lasted for a long time. A lot of research work on this mechanism has been done by both the shear and diffusion schools. Results from these two schools have many differences and the viewpoints on them are different essentially as
基金Project supported by the National Science Foundation of Shandong Province.
文摘The fine structure of bainite,the morphology and distribution of carbide in steels and the morphology of bainite in Cu-Zn-Al alloys have been investigated with TEM.The interfacial structure ledges and interfacial crystal lattice images of Cu-Zn-Al alloys have also been investigated with HREM.The addition of alloying microelements can fine the structure of bainitic ferrite markedly.The bainitic ferrite is composed of subunits or subchunks.The carbides differ in morphologies and are distributed in between laths,inside the plates and on the boundaries of subunits.There are abundant fine structures in bainitic ferrite.In the primary bainite of Cu-Zn-Al alloy there are interfacial structure ledges,the height of which is about 3 -40 nm,equal to 15-200 atomic layers.The phase transformation mechanism of bainite is discussed.
文摘Let D be a nonsquare integer and p be an odd prime with p(?)D. The equation x^2-D=p^n, x>0, n>0 (1) is usually called the generalized Ramanujan-Nagell equation. For this equation, there are many related works written by Alter and Kubota, Brown, Cohen and lnkeri. In this letter, we shall prove the
基金supported from the National Natural Science Foundation of China (Grant No. 1171088)the National Basic Research Program of China (Grant No. 12CB619403) from Chinese Ministry of Science and Technology
文摘The geometrical matching/mismatching of lattices overlapped in 1, 2 and 3 dimensions have been analyzed systematically by variation of lattice misfit in a large range, far beyond the limits for semicoherent interfaces. In order to evaluate the degree of matching, the density of good matching site （GMS） between two lattices is calculated. The analysis shows that the GMS density remains approximately constant, irrespectively to the degree of lattice misfit. This constant, defined as the average GMS density, decreases exponentially with the increasing dimension of misfit. Typically, for 6 = 15%, the average GMS densities are approximately 30%, 7%, and 1.4% for 1D, 2D, and 3D lattice misfits, respectively. The GMS density deviates significantly if a CSL of small X can be defined. The relationship between the GMS distribution and O-lattice is investigated. It indicates that an abrupt increase in the GMS density in an interface parallel to a principal O-lattice plane is equivalent to a reduction of dimension of misfit. This shows the agreement between the selections of principal O-lattice planes as candidates of the preferred interfaces and the condition that interfaces with high GMS density are preferred.
