On the basis of literature review,this paper discusses what interactional strategies are in group discussions conducted in the EFL classroom.Two frameworks for interactional strategies are investigated to explore the ...On the basis of literature review,this paper discusses what interactional strategies are in group discussions conducted in the EFL classroom.Two frameworks for interactional strategies are investigated to explore the types of interactional strategies.This aims to shed light upon the analysis of interactional features in face-to-face communication.展开更多
This paper describes a shake table test study on the seismic response of low-cap pile groups and a bridge structure in liquefiable ground. The soil profile, contained in a large-scale laminar shear box, consisted of a...This paper describes a shake table test study on the seismic response of low-cap pile groups and a bridge structure in liquefiable ground. The soil profile, contained in a large-scale laminar shear box, consisted of a horizontally saturated sand layer overlaid with a silty clay layer, with the simulated low-cap pile groups embedded. The container was excited in three E1 Centro earthquake events of different levels. Test results indicate that excessive pore pressure (EPP) during slight shaking only slightly accumulated, and the accumulation mainly occurred during strong shaking. The EPP was gradually enhanced as the amplitude and duration of the input acceleration increased. The acceleration response of the sand was remarkably influenced by soil liquefaction. As soil liquefaction occurred, the peak sand displacement gradually lagged behind the input acceleration; meanwhile, the sand displacement exhibited an increasing effect on the bending moment of the pile, and acceleration responses of the pile and the sand layer gradually changed from decreasing to increasing in the vertical direction from the bottom to the top. A jump variation of the bending moment on the pile was observed near the soil interface in all three input earthquake events. It is thought that the shake table tests could provide the groundwork for further seismic performance studies of low-cap pile groups used in bridges located on liquefiable groun.展开更多
A simplified approach is presented for the analysis of the settlement of vertically loaded pile groups. In order to simulate the nonlinear pile-to-pile interaction in pile groups, the soils along the piles are assumed...A simplified approach is presented for the analysis of the settlement of vertically loaded pile groups. In order to simulate the nonlinear pile-to-pile interaction in pile groups, the soils along the piles are assumed to behave as a series of nonlinear springs subjected to the shaft shear stress at the pile/soil interface. Considering the displacement reduction induced by the pile-to-pile interaction, the shear-deformation method is adopted to approximate the displacement field of the layered soils around the piles, and the equivalent stiffness of the springs is obtained. Furthermore, the load-settlement response of pile groups is deduced by modifying the load-transfer functions to account for the pile-to-pile interaction. The settlements of a laboratory pile groups computed by the presented approach are in a good agreement with measured results. The analysis on Contrastive parameters shows that the settlements of pile group decrease with the increase of the pile space and pile length, and the part of piles exceeding the critical pile length has little contribution to the beating capacity of the pile groups.展开更多
The interaction between pile and soft soil of the passive pile group subjected to soil movement was analyzed with three-dimensional finite element model by using ANSYS software. The soil was assumed to be elastic-plas...The interaction between pile and soft soil of the passive pile group subjected to soil movement was analyzed with three-dimensional finite element model by using ANSYS software. The soil was assumed to be elastic-plastic complying with the Drucker-Prager yield criterion in the analysis. The large displacement of soil was considered and contact elements were used to evaluate the interaction between pile and soil. The influences of soil depth of layer and number of piles on the lateral pressure of the pile were investigated, and the lateral pressure distributions on the (2×1) pile group and on the (2×2) pile group were compared. The results show that the adjacent surcharge may result in significant lateral movement of the soft soil and considerable pressure on the pile. The pressure acting on the row near the surcharge is higher than that on the other row, due to the "barrier" and arching effects in pile groups. The passive load and its distribution should be taken into account in the design of the passive piles.展开更多
A main-chain liquid crystalline ionomer(MLCI) containing sulfonic group was synthesized by an interfacial condensation reaction.The MLCI was blended with polybutylene terephthalate(PBT) and polypropylene(PP).MLC...A main-chain liquid crystalline ionomer(MLCI) containing sulfonic group was synthesized by an interfacial condensation reaction.The MLCI was blended with polybutylene terephthalate(PBT) and polypropylene(PP).MLCI interacted with both the dispersed(PP) phase and the matrix(PBT) phase to modify the interfacial interaction of PBT and PP.Differential scanning calorimetry(DSC),scanning electron microscopy(SEM) and FTIR imaging system analysis demonstrated the significance of interfacial interaction in the polymer blends.MLCI brought about good adhesion at the interfacial,which reduced the disperse phase size and enabled a fine PP phase at matrix.The mechanical properties of the ternary blends were improved when a proper amount of MLCI was added.This was attributed to enhanced adhesion at the interface,which invoked better mechanical properties in the blends.展开更多
Isobaric vapor-liquid equilibria (VLE) are experimentally measured for the binary systems of dimethyl carbonate (DMC)+ ethylene carbonate and methanol + ethylene carbonate at 101.325kPa. The thermodynamic consistency ...Isobaric vapor-liquid equilibria (VLE) are experimentally measured for the binary systems of dimethyl carbonate (DMC)+ ethylene carbonate and methanol + ethylene carbonate at 101.325kPa. The thermodynamic consistency of these experimental data is tested with an available statistic method. Interaction parameters of the carbonate group -OCOO- with the group -CH3, ACH, CH3OH and CH3COO- in UNIFAC model are determined using the experimental and literature VLE data. The results show that the calculated VLE data using the new UNIFAC parameters agree excellently with the experimental data in this work and in literature. These results are useful in the research on DMC and diphenyl carbonate synthesis by transesterification in design of reactor and distillation tower.展开更多
To prepare a highly efficient NiMo/Al_(2)O_(3) hydrodesulfurization catalyst,the combined effects of specific organic functional groups and alumina surface characteristics were investigated.First,the correlation betwe...To prepare a highly efficient NiMo/Al_(2)O_(3) hydrodesulfurization catalyst,the combined effects of specific organic functional groups and alumina surface characteristics were investigated.First,the correlation between the surface characteristics of four different alumina and the existing Mo species states was established.It was found that the Mo equilibrium adsorption capacity can be used as a specific descriptor to quantitatively evaluate the changes in surface characteristics of different alumina.A lower Mo equilibrium adsorption capacity for alumina means weaker metal-support interaction and the loaded Mo species are easier to transform into MoS2.However,the Mo-O-Al bonds still exist at the metal-support interface.The introduction of cationic surfactant hecadecyl trimethyl ammonium bromide(CTAB)can further improve Mo species dispersion through electrostatic attraction with Mo anions and interaction of its alkyl chain with the alumina surface;meanwhile,the introduction of ethylenediamine tetraacetic acid(EDTA)can complex with Ni ions to enhance the Ni-promoting effect on Mo.Therefore,the NiMo catalyst designed using alumina with lower Mo equilibrium adsorption capacity and the simultaneous addition of EDTA and CTAB exhibits the highest hydrodesulfurization activity for 4,6-dimethyl dibenzothiophene because of its proper metal-support interaction and more well-dispersed Ni-Mo-S active phases.展开更多
The traditional teacher-centered ESL class has been prevalent in China for years. Under this circumstance, teachers tend to adopt a spoon-fed teaching method, and become the dominator in ESL class by setting the same ...The traditional teacher-centered ESL class has been prevalent in China for years. Under this circumstance, teachers tend to adopt a spoon-fed teaching method, and become the dominator in ESL class by setting the same instructional pace, explaining a grammar point, leading drill work; while the students' in-class participation is relatively low. As a result, students with different learning styles often feel suffocated in this teacher-dominated class; they desire to have more opportunities to participate in the free interactions or group discussions.Based on the theoretical framework of interactive teaching approach suggested by Lightbown and Spada(1993),the research aims to analyze the merits of students' in-group interaction and to examine the feasibility of implementing it in Chinese ESL class. The research reveals that in-group interaction can cultivate students' independent learning habits by granting them autonomy to bring about the problem and tackle them. Nonetheless, different perceptions from several students and teachers upon group work may influence the usefulness. The research strives to be instructive for the more efficient application of in-group interaction in Chinese ESL class.展开更多
In foreign language teaching, the communicative approach has been a dominant method for decades. However, some misconceptions of the communicative approach affect the results of group interaction teaching. This articl...In foreign language teaching, the communicative approach has been a dominant method for decades. However, some misconceptions of the communicative approach affect the results of group interaction teaching. This article tries to explore some existing problems as well as some relevant solution in the application of group activities in colleges with the aid of observation, questionnaire and interview.展开更多
Quantitative description of vapor-liquid equilibrium is very useful for designing separation processes. In this study, we combined the Peng-Robinson equation and the Huron-Vidal-Orbey-Sandler mixing rule into a modifi...Quantitative description of vapor-liquid equilibrium is very useful for designing separation processes. In this study, we combined the Peng-Robinson equation and the Huron-Vidal-Orbey-Sandler mixing rule into a modified UNIFAC model for the improvement of predicting vapor-liquid equilibria. The predictions of vapor-liquid equilibria for 62 systems including alcohol- alkane, alcohol-benzene, and amine-water systems demonstrate that the revised parameters remarkably improve the prediction accuracy for many systems. Especially for amine-water system, the mean deviation of components decreases from 0.094 to 0.021, and the mean deviation of pressure from 22.45% to 4.41%.展开更多
Classroom interaction plays a critical role in language teaching and learning process.It involves both the teacher-students,and students-students.This article is intended to explore the vital significance of classroom...Classroom interaction plays a critical role in language teaching and learning process.It involves both the teacher-students,and students-students.This article is intended to explore the vital significance of classroom interaction in language learning process with the emphasis placed on the students' involvement in the classroom activities,furthermore,to discover whether the peers small-sized group work is a beneficial and irreplaceable form of classroom interaction.展开更多
Economic growth and environmental "friendliness" are the dual missions of China's grand western development. In the past eight years,China has seen the gap between eastern and western regions still widen...Economic growth and environmental "friendliness" are the dual missions of China's grand western development. In the past eight years,China has seen the gap between eastern and western regions still widening while also taking on the arduous task of protecting nature,ecology and environment in the western region. How has western development fared in the past eight years? What difficulties and challenges are being encountered? The development of the western region poses the single greatest difficulty facing China's regional economic development,but how can we advance along a "sound and fast" development path? The establishment of economic zones in Chengdu and Chongqing,Guanzhong and North Bay has opened up new possibilities and expectations for western China's economic development.展开更多
This paper is committed to exploring the importance of learner learner interaction for language learning. It starts with a discussion of the roles that learner learner interaction plays in language learning from two p...This paper is committed to exploring the importance of learner learner interaction for language learning. It starts with a discussion of the roles that learner learner interaction plays in language learning from two points of view pedagogic and psycholinguistic, which is followed by a brief guideline for organizing group work in class.展开更多
A series of study and investigation has been made on the basis of the theory of group work. The purpose is to study the effectiveness of group work in the interaction class, thus to attract more English teachers' att...A series of study and investigation has been made on the basis of the theory of group work. The purpose is to study the effectiveness of group work in the interaction class, thus to attract more English teachers' attention to seek for the new approach to the breakthrough of traditional English class mode.展开更多
Group decision making problems are investigated with uncertain multiplicative linguistic preference relations.An unbalanced multiplicative linguistic label set is introduced,which can be used by the experts to express...Group decision making problems are investigated with uncertain multiplicative linguistic preference relations.An unbalanced multiplicative linguistic label set is introduced,which can be used by the experts to express their linguistic preference information over alternatives.The uncertain linguistic weighted geometric mean operator is utilized to aggregate all the individual uncertain multiplicative linguistic preference relations into a collective one,and then a simple approach is developed to determine the experts' weights by utilizing the consensus degrees among the individual uncertain multiplicative linguistic preference relations and the collective uncertain multiplicative linguistic preference relations.Furthermore,a practical interactive procedure for group decision making is proposed based on uncertain multiplicative linguistic preference relations,in which a possibility degree formula and a complementary matrix are used to rank the given alternatives.Finally,the proposed procedure is applied to solve the group decision making problem of a manufacturing company searching the best global supplier for one of its most critical parts used in assembling process.展开更多
Engineering the surface microenvironment by tuning the binary interactions between a supported metal with a secondary metal oxide(MO_(x))or support has been a common method for improving the catalytic performance of s...Engineering the surface microenvironment by tuning the binary interactions between a supported metal with a secondary metal oxide(MO_(x))or support has been a common method for improving the catalytic performance of supported metal catalysts.However,few studies have investigated the ternary interactions among the metal,MO_(x),and support.Here,we report for the first time the formation of metal-MO_(x)-support interaction(MMSI)in reducible TiO_(2)-supported PtReO_(x) catalysts,affording 87% yield and 100% ee in the tandem hydrogenation of an aqueous chiral cyclohexane-1,2-dicarboxylic acid into the corresponding diol;the catalytic activity is eight times higher than that obtained with non-reducible support counterparts in the same reaction via traditional batch synthesis with multiple steps and unfriendly reagents.Detailed experimental and computational studies suggest that the TiO_(2) crystalline phase-dependent density of the oxygen vacancies induces different Pt-ReO_(x)-TiO_(2) interactions,which dominate the electron transfer therein and tune the adsorption strength of the carbonyl moiety of the substrate/intermediate,thus promoting the hydrogenation activity and selectivity.In addition,the strong MMSI endows the optimal rutile TiO_(2) supported PtReO_(x) catalyst with an outstanding lifetime of 400 h in a fixed-bed reactor under acidic aqueous conditions and ensures efficient applications in the selective hydrogenation of aliphatic dicarboxylic acids and functional carboxylic acids.This work provides a promising strategy for the development of efficient and stable supported catalysts for the selective hydrogenation of diverse C-O and C=O bonds.展开更多
The effect of chemical structure of segmented poly(urethane-urea)s on its interfacial interactions with poly(vinyl chloride) as well as supramolecular structure and the properties of prepared composites has been studi...The effect of chemical structure of segmented poly(urethane-urea)s on its interfacial interactions with poly(vinyl chloride) as well as supramolecular structure and the properties of prepared composites has been studied. A direct influence of flexible and rigid segments of elastomers on a compatibility, structure and the physical-mechanical properties of poly(urethane-urea)/poly(vinyl chloride) blends was investigated. A formation of intermolecular hydrogen bonds network in the poly(urethane-urea)/poly(vinyl chloride) systems was evaluated by FTIR analysis. Morphology studies have shown the effect of interfacial interactions on a size of thermoplastic phase dispersed within elastomer matrix. Obtained poly(urethane-urea)/poly(vinyl chloride) micro- and nanocomposites have improved tensile properties.展开更多
Three Clifford algebras are sufficient to describe all interactions of modern physics: The Clifford algebra of the usual space is enough to describe all aspects of electromagnetism, including the quantum wave of the e...Three Clifford algebras are sufficient to describe all interactions of modern physics: The Clifford algebra of the usual space is enough to describe all aspects of electromagnetism, including the quantum wave of the electron. The Clifford algebra of space-time is enough for electro-weak interactions. To get the gauge group of the standard model, with electro-weak and strong interactions, a third algebra is sufficient, with only two more dimensions of space. The Clifford algebra of space allows us to include also gravitation. We discuss the advantages of our approach.展开更多
Non-Interactive Zero-Knowledge(NIZK for short) proofs are fascinating and extremely useful in many security protocols. In this paper,a new group signature scheme,decisional linear assumption group signature(DLAGS for ...Non-Interactive Zero-Knowledge(NIZK for short) proofs are fascinating and extremely useful in many security protocols. In this paper,a new group signature scheme,decisional linear assumption group signature(DLAGS for short) with NIZK proofs is proposed which can prove and sign the multiple values rather than individual bits based on DLIN assumption. DLAGS does not need to interact between the verifier and issuer,which can decrease the communication times and storage cost compared with the existing interactive group signature schemes. We prove and sign the blocks of messages instead of limiting the proved message to only one bit(0 or 1) in the conventional non-interactive zero-knowledge proof system,and we also prove that our scheme satisfy the property of anonymity,unlinkability and traceability. Finally,our scheme is compared with the other scheme(Benoitt's scheme) which is also based on the NIZK proofs system and the DLIN assumption,and the results show that our scheme requires fewer members of groups and computational times.展开更多
文摘On the basis of literature review,this paper discusses what interactional strategies are in group discussions conducted in the EFL classroom.Two frameworks for interactional strategies are investigated to explore the types of interactional strategies.This aims to shed light upon the analysis of interactional features in face-to-face communication.
基金Major Research Plan of National Natural Science Foundation of China Under Grant No.90815009National Natural Science Foundation of China Under Grant No.50378031 and 50178027Western Transport Construction Technology Projects Under Grant No.2009318000100
文摘This paper describes a shake table test study on the seismic response of low-cap pile groups and a bridge structure in liquefiable ground. The soil profile, contained in a large-scale laminar shear box, consisted of a horizontally saturated sand layer overlaid with a silty clay layer, with the simulated low-cap pile groups embedded. The container was excited in three E1 Centro earthquake events of different levels. Test results indicate that excessive pore pressure (EPP) during slight shaking only slightly accumulated, and the accumulation mainly occurred during strong shaking. The EPP was gradually enhanced as the amplitude and duration of the input acceleration increased. The acceleration response of the sand was remarkably influenced by soil liquefaction. As soil liquefaction occurred, the peak sand displacement gradually lagged behind the input acceleration; meanwhile, the sand displacement exhibited an increasing effect on the bending moment of the pile, and acceleration responses of the pile and the sand layer gradually changed from decreasing to increasing in the vertical direction from the bottom to the top. A jump variation of the bending moment on the pile was observed near the soil interface in all three input earthquake events. It is thought that the shake table tests could provide the groundwork for further seismic performance studies of low-cap pile groups used in bridges located on liquefiable groun.
基金Project(50708033) supported by the National Natural Science Foundation of ChinaProjects(200923, CXKJSF0108-2) supported by Transportation Technical Project of Hunan Province, China
文摘A simplified approach is presented for the analysis of the settlement of vertically loaded pile groups. In order to simulate the nonlinear pile-to-pile interaction in pile groups, the soils along the piles are assumed to behave as a series of nonlinear springs subjected to the shaft shear stress at the pile/soil interface. Considering the displacement reduction induced by the pile-to-pile interaction, the shear-deformation method is adopted to approximate the displacement field of the layered soils around the piles, and the equivalent stiffness of the springs is obtained. Furthermore, the load-settlement response of pile groups is deduced by modifying the load-transfer functions to account for the pile-to-pile interaction. The settlements of a laboratory pile groups computed by the presented approach are in a good agreement with measured results. The analysis on Contrastive parameters shows that the settlements of pile group decrease with the increase of the pile space and pile length, and the part of piles exceeding the critical pile length has little contribution to the beating capacity of the pile groups.
基金Project(50378036) supported by the National Natural Science Foundation of China
文摘The interaction between pile and soft soil of the passive pile group subjected to soil movement was analyzed with three-dimensional finite element model by using ANSYS software. The soil was assumed to be elastic-plastic complying with the Drucker-Prager yield criterion in the analysis. The large displacement of soil was considered and contact elements were used to evaluate the interaction between pile and soil. The influences of soil depth of layer and number of piles on the lateral pressure of the pile were investigated, and the lateral pressure distributions on the (2×1) pile group and on the (2×2) pile group were compared. The results show that the adjacent surcharge may result in significant lateral movement of the soft soil and considerable pressure on the pile. The pressure acting on the row near the surcharge is higher than that on the other row, due to the "barrier" and arching effects in pile groups. The passive load and its distribution should be taken into account in the design of the passive piles.
基金Supported by the High-Tech Research and Development Program of China(No.2006AA02Z291)the National Natural Science Foundation of China(No.50673105)
文摘A main-chain liquid crystalline ionomer(MLCI) containing sulfonic group was synthesized by an interfacial condensation reaction.The MLCI was blended with polybutylene terephthalate(PBT) and polypropylene(PP).MLCI interacted with both the dispersed(PP) phase and the matrix(PBT) phase to modify the interfacial interaction of PBT and PP.Differential scanning calorimetry(DSC),scanning electron microscopy(SEM) and FTIR imaging system analysis demonstrated the significance of interfacial interaction in the polymer blends.MLCI brought about good adhesion at the interfacial,which reduced the disperse phase size and enabled a fine PP phase at matrix.The mechanical properties of the ternary blends were improved when a proper amount of MLCI was added.This was attributed to enhanced adhesion at the interface,which invoked better mechanical properties in the blends.
文摘Isobaric vapor-liquid equilibria (VLE) are experimentally measured for the binary systems of dimethyl carbonate (DMC)+ ethylene carbonate and methanol + ethylene carbonate at 101.325kPa. The thermodynamic consistency of these experimental data is tested with an available statistic method. Interaction parameters of the carbonate group -OCOO- with the group -CH3, ACH, CH3OH and CH3COO- in UNIFAC model are determined using the experimental and literature VLE data. The results show that the calculated VLE data using the new UNIFAC parameters agree excellently with the experimental data in this work and in literature. These results are useful in the research on DMC and diphenyl carbonate synthesis by transesterification in design of reactor and distillation tower.
基金funding of the National Key Research and Development Plan(Grant 2017YFB0306600)the Project of SINOPEC(NO.117006).
文摘To prepare a highly efficient NiMo/Al_(2)O_(3) hydrodesulfurization catalyst,the combined effects of specific organic functional groups and alumina surface characteristics were investigated.First,the correlation between the surface characteristics of four different alumina and the existing Mo species states was established.It was found that the Mo equilibrium adsorption capacity can be used as a specific descriptor to quantitatively evaluate the changes in surface characteristics of different alumina.A lower Mo equilibrium adsorption capacity for alumina means weaker metal-support interaction and the loaded Mo species are easier to transform into MoS2.However,the Mo-O-Al bonds still exist at the metal-support interface.The introduction of cationic surfactant hecadecyl trimethyl ammonium bromide(CTAB)can further improve Mo species dispersion through electrostatic attraction with Mo anions and interaction of its alkyl chain with the alumina surface;meanwhile,the introduction of ethylenediamine tetraacetic acid(EDTA)can complex with Ni ions to enhance the Ni-promoting effect on Mo.Therefore,the NiMo catalyst designed using alumina with lower Mo equilibrium adsorption capacity and the simultaneous addition of EDTA and CTAB exhibits the highest hydrodesulfurization activity for 4,6-dimethyl dibenzothiophene because of its proper metal-support interaction and more well-dispersed Ni-Mo-S active phases.
文摘The traditional teacher-centered ESL class has been prevalent in China for years. Under this circumstance, teachers tend to adopt a spoon-fed teaching method, and become the dominator in ESL class by setting the same instructional pace, explaining a grammar point, leading drill work; while the students' in-class participation is relatively low. As a result, students with different learning styles often feel suffocated in this teacher-dominated class; they desire to have more opportunities to participate in the free interactions or group discussions.Based on the theoretical framework of interactive teaching approach suggested by Lightbown and Spada(1993),the research aims to analyze the merits of students' in-group interaction and to examine the feasibility of implementing it in Chinese ESL class. The research reveals that in-group interaction can cultivate students' independent learning habits by granting them autonomy to bring about the problem and tackle them. Nonetheless, different perceptions from several students and teachers upon group work may influence the usefulness. The research strives to be instructive for the more efficient application of in-group interaction in Chinese ESL class.
文摘In foreign language teaching, the communicative approach has been a dominant method for decades. However, some misconceptions of the communicative approach affect the results of group interaction teaching. This article tries to explore some existing problems as well as some relevant solution in the application of group activities in colleges with the aid of observation, questionnaire and interview.
文摘Quantitative description of vapor-liquid equilibrium is very useful for designing separation processes. In this study, we combined the Peng-Robinson equation and the Huron-Vidal-Orbey-Sandler mixing rule into a modified UNIFAC model for the improvement of predicting vapor-liquid equilibria. The predictions of vapor-liquid equilibria for 62 systems including alcohol- alkane, alcohol-benzene, and amine-water systems demonstrate that the revised parameters remarkably improve the prediction accuracy for many systems. Especially for amine-water system, the mean deviation of components decreases from 0.094 to 0.021, and the mean deviation of pressure from 22.45% to 4.41%.
文摘Classroom interaction plays a critical role in language teaching and learning process.It involves both the teacher-students,and students-students.This article is intended to explore the vital significance of classroom interaction in language learning process with the emphasis placed on the students' involvement in the classroom activities,furthermore,to discover whether the peers small-sized group work is a beneficial and irreplaceable form of classroom interaction.
文摘Economic growth and environmental "friendliness" are the dual missions of China's grand western development. In the past eight years,China has seen the gap between eastern and western regions still widening while also taking on the arduous task of protecting nature,ecology and environment in the western region. How has western development fared in the past eight years? What difficulties and challenges are being encountered? The development of the western region poses the single greatest difficulty facing China's regional economic development,but how can we advance along a "sound and fast" development path? The establishment of economic zones in Chengdu and Chongqing,Guanzhong and North Bay has opened up new possibilities and expectations for western China's economic development.
文摘This paper is committed to exploring the importance of learner learner interaction for language learning. It starts with a discussion of the roles that learner learner interaction plays in language learning from two points of view pedagogic and psycholinguistic, which is followed by a brief guideline for organizing group work in class.
文摘A series of study and investigation has been made on the basis of the theory of group work. The purpose is to study the effectiveness of group work in the interaction class, thus to attract more English teachers' attention to seek for the new approach to the breakthrough of traditional English class mode.
基金supported by the National Natural Science Foundation of China (70571087)the National Science Fund for Distinguished Young Scholars of China (70625005)
文摘Group decision making problems are investigated with uncertain multiplicative linguistic preference relations.An unbalanced multiplicative linguistic label set is introduced,which can be used by the experts to express their linguistic preference information over alternatives.The uncertain linguistic weighted geometric mean operator is utilized to aggregate all the individual uncertain multiplicative linguistic preference relations into a collective one,and then a simple approach is developed to determine the experts' weights by utilizing the consensus degrees among the individual uncertain multiplicative linguistic preference relations and the collective uncertain multiplicative linguistic preference relations.Furthermore,a practical interactive procedure for group decision making is proposed based on uncertain multiplicative linguistic preference relations,in which a possibility degree formula and a complementary matrix are used to rank the given alternatives.Finally,the proposed procedure is applied to solve the group decision making problem of a manufacturing company searching the best global supplier for one of its most critical parts used in assembling process.
文摘Engineering the surface microenvironment by tuning the binary interactions between a supported metal with a secondary metal oxide(MO_(x))or support has been a common method for improving the catalytic performance of supported metal catalysts.However,few studies have investigated the ternary interactions among the metal,MO_(x),and support.Here,we report for the first time the formation of metal-MO_(x)-support interaction(MMSI)in reducible TiO_(2)-supported PtReO_(x) catalysts,affording 87% yield and 100% ee in the tandem hydrogenation of an aqueous chiral cyclohexane-1,2-dicarboxylic acid into the corresponding diol;the catalytic activity is eight times higher than that obtained with non-reducible support counterparts in the same reaction via traditional batch synthesis with multiple steps and unfriendly reagents.Detailed experimental and computational studies suggest that the TiO_(2) crystalline phase-dependent density of the oxygen vacancies induces different Pt-ReO_(x)-TiO_(2) interactions,which dominate the electron transfer therein and tune the adsorption strength of the carbonyl moiety of the substrate/intermediate,thus promoting the hydrogenation activity and selectivity.In addition,the strong MMSI endows the optimal rutile TiO_(2) supported PtReO_(x) catalyst with an outstanding lifetime of 400 h in a fixed-bed reactor under acidic aqueous conditions and ensures efficient applications in the selective hydrogenation of aliphatic dicarboxylic acids and functional carboxylic acids.This work provides a promising strategy for the development of efficient and stable supported catalysts for the selective hydrogenation of diverse C-O and C=O bonds.
文摘The effect of chemical structure of segmented poly(urethane-urea)s on its interfacial interactions with poly(vinyl chloride) as well as supramolecular structure and the properties of prepared composites has been studied. A direct influence of flexible and rigid segments of elastomers on a compatibility, structure and the physical-mechanical properties of poly(urethane-urea)/poly(vinyl chloride) blends was investigated. A formation of intermolecular hydrogen bonds network in the poly(urethane-urea)/poly(vinyl chloride) systems was evaluated by FTIR analysis. Morphology studies have shown the effect of interfacial interactions on a size of thermoplastic phase dispersed within elastomer matrix. Obtained poly(urethane-urea)/poly(vinyl chloride) micro- and nanocomposites have improved tensile properties.
文摘Three Clifford algebras are sufficient to describe all interactions of modern physics: The Clifford algebra of the usual space is enough to describe all aspects of electromagnetism, including the quantum wave of the electron. The Clifford algebra of space-time is enough for electro-weak interactions. To get the gauge group of the standard model, with electro-weak and strong interactions, a third algebra is sufficient, with only two more dimensions of space. The Clifford algebra of space allows us to include also gravitation. We discuss the advantages of our approach.
基金supported by the National High-Tech Research and Development Plan of China under Grant Nos.863-317-01- 04-99, 2009AA01Z122 (863)the Natural Science Foundation of Shenyang City of China under Grant No. F10-205-1-12
文摘Non-Interactive Zero-Knowledge(NIZK for short) proofs are fascinating and extremely useful in many security protocols. In this paper,a new group signature scheme,decisional linear assumption group signature(DLAGS for short) with NIZK proofs is proposed which can prove and sign the multiple values rather than individual bits based on DLIN assumption. DLAGS does not need to interact between the verifier and issuer,which can decrease the communication times and storage cost compared with the existing interactive group signature schemes. We prove and sign the blocks of messages instead of limiting the proved message to only one bit(0 or 1) in the conventional non-interactive zero-knowledge proof system,and we also prove that our scheme satisfy the property of anonymity,unlinkability and traceability. Finally,our scheme is compared with the other scheme(Benoitt's scheme) which is also based on the NIZK proofs system and the DLIN assumption,and the results show that our scheme requires fewer members of groups and computational times.