By introducing a fictitious mode to be a counterpart mode of the system mode under review we introduce the entangled state representation (η|, which can arrange master equations of density operators p(t) in quant...By introducing a fictitious mode to be a counterpart mode of the system mode under review we introduce the entangled state representation (η|, which can arrange master equations of density operators p(t) in quantum statistics as state-vector evolution equations due to the elegant properties of (η|. In this way many master equations (respectively describing damping oscillator, laser, phase sensitive, and phase diffusion processes with different initial density operators) can be concisely solved. Specially, for a damping process characteristic of the decay constant k we find that the matrix element of p(t) at time t in 〈η| representation is proportional to that of the initial po in the decayed entangled state (ηe^-kt| representation, accompanying with a Gaussian damping factor. Thus we have a new insight about the nature of the dissipative process. We also set up the so-called thermo-entangled state representation of density operators, ρ = f(d^2η/π)(η|ρ〉D(η), which is different from all the previous known representations.展开更多
In this work we investigated the effect of nitric acid concentration on the pore structure,surface chemistry and liquid phase adsorption of olive stone based activated carbon prepared by mixing process using phosphori...In this work we investigated the effect of nitric acid concentration on the pore structure,surface chemistry and liquid phase adsorption of olive stone based activated carbon prepared by mixing process using phosphoric acid and steam as activating agents.Chemicals and textural characterization show that the increase of HNO3concentration increases considerably the total acidic groups but decreases specific surface area and pore volume.The study of adsorption in aqueous solutions of two organics,phenol and methylene blue,on raw and oxidized activated carbon indicates that the treatment of mixed activated carbon with different concentrations of nitric acid improves the adsorbent capacity for methylene blue at HNO3concentrations less or equal to 2 mol·L 1,while it has a negative effect on phenol adsorption.展开更多
In this study,we present the characterization of the carbon fibers recovered from the mechanochemical-enhanced recycling of carbon fiber reinforced fibers.The objectives of the study were to investigate the effect of ...In this study,we present the characterization of the carbon fibers recovered from the mechanochemical-enhanced recycling of carbon fiber reinforced fibers.The objectives of the study were to investigate the effect of our modified recycling method on the interfacial properties of recovered fibers.The reinforced plastics were recycled;the recycling efficiency was determined and the recovered fibers were sized using 1 wt%and 3 wt%concentration of(3-aminopropyl)triethoxysilane.We characterized the morphologies utilizing the electron spectroscopy for chemical analysis(ESCA),atomic force microscopy(AFM),FTIR-attenuated total reflection(ATR)spectroscopy and scanning electron microscopy(SEM).Although the surface of the fibers had no cracks,there was evidence of contaminations which affected the interfacial properties and the quality of the fibers.Results showed that the trends in the recovered and virgin fibers were similar with an increase in sizing concentration.The results highlighted the perspectives of increasing the quality of recovered fibers after the recycling process.展开更多
This study deals with the development of statistical modeling for water wave surface elevation by using a method that combines a dynamic solution with random process statistics. Ocean wave data taken from four NOAA (...This study deals with the development of statistical modeling for water wave surface elevation by using a method that combines a dynamic solution with random process statistics. Ocean wave data taken from four NOAA (National Oceanic and Atmospheric Administration) buoys moored in the northeast Pacific were used to validate the model. The results indicated that the nonlinear probability density distribution of ocean wave surface elevation derived from the model described the measurements much better than Gaussian distribution and Longuet-Higgins distribution.展开更多
This work describes a simple yet powerful scalable solution chemistry strategy to create back‐contact rich interfaces between substrates such as commercial transparent conducting fluorine‐doped tin oxide coated glas...This work describes a simple yet powerful scalable solution chemistry strategy to create back‐contact rich interfaces between substrates such as commercial transparent conducting fluorine‐doped tin oxide coated glass(FTO)and photoactive thin films such as hematite for low‐cost water oxidation reaction.High‐resolution electron microscopy(SEM,TEM,STEM),atomic force microscopy(AFM),elemental chemical mapping(EELS,EDS)and photoelectrochemical(PEC)investigations reveal that the mechanical stress,lattice mismatch,electron energy barrier,and voids between FTO and hematite at the back‐contact interface as well as short‐circuit and detrimental reaction between FTO and the electrolyte can be alleviated by engineering the chemical composition of the precursor solutions,thus increasing the overall efficiency of these low‐cost photoanodes for water oxidation reaction for a clean and sustainable generation of hydrogen from PEC water‐splitting.These findings are of significant importance to improve the charge collection efficiency by minimizing electron‐hole recombination observed at back‐contact interfaces and grain boundaries in mesoporous electrodes,thus improving the overall efficiency and scalability of low‐cost PEC water splitting devices.展开更多
In this paper, we conduct analysis on the optimization approaches of contemporary piano education system from the perspective of music knowledge integration. In the process of the piano teaching, teacher and school th...In this paper, we conduct analysis on the optimization approaches of contemporary piano education system from the perspective of music knowledge integration. In the process of the piano teaching, teacher and school the training of musicianship as the key point of teaching. This is because the skill can through student plays to display directly, appraises the student performance technique quality an important criterion. However, the student has the excellent adept technique merely also by far insufficient, but also needs the high artistic aesthetic ability, not only need be able to appreciate the piano performance, but must be able to reveal the artistic aesthetic feature in the process of piano performance. Piano education as one of the ways of music education, and other subjects, there is the subject of the universal education as its educational ideas, educational ideas and teaching methods, a direct impact on the generation after generation of the comprehensive quality of education. Under this basis, we propose the new idea on the issues that will be beneficial.展开更多
A series of char samples were derived from pyrolysis of two typical low-rank coals in China (Shengli lig- nite and Shenmu bituminous coal) at low, medium and fast heating rates, respectively, to the same pyrol- ysis...A series of char samples were derived from pyrolysis of two typical low-rank coals in China (Shengli lig- nite and Shenmu bituminous coal) at low, medium and fast heating rates, respectively, to the same pyrol- ysis temperature 750℃. Then these chars were characterized by means of thermogravimetric analysis and Fourier transform infrared spectrometer with the aim to investigate the influence of heating rate in pyrolysis process on gasification reactivity and surface chemistry of them. Besides, a homogeneous model was used to quantitatively analyze the activation energy of gasification reaction. The results reveal that Shengli lignite and its derived chars behave higher gasification reactivity and have less content of oxygen functional groups than Shenmu coal and chars. Meanwhile, chars derived from Shengli lignite at 50℃/min and Shenmu coal at 200℃/min have the greatest gasification reactivity, respectively. The oxygen functional groups in Shengli lignite are easily thermo-decomposed, and they are less affected by the heating rate, while that in Shenmu coal have a significant change with the variation of heating rate. In addition, there is no good correlation between the change of oxygen functional groups and that of the gasification reactivity of the derived chars from pyrolysis at different heating rates.展开更多
Based on the author’s previously obtained results on P and Si forms in southern Bohai Sea surface sediments,this study mainly foucusing on the controlling factors, existence forms, and biogeochemical processes of P a...Based on the author’s previously obtained results on P and Si forms in southern Bohai Sea surface sediments,this study mainly foucusing on the controlling factors, existence forms, and biogeochemical processes of P and Si showed that the transferable forms of phosphorus in sediments were mainly controlled by the mineralization of organic matters and the reduction of high valence iron; whereas the transferable forms of silicon were possibly controlled by the dissolution and precipitation as well as biochemical processes of living organisms.展开更多
This study views pedagogical translation as a means of developing language skills, especially oral communication. Contrary to the claim that translation focuses only on reading and writing, this study presents anecdot...This study views pedagogical translation as a means of developing language skills, especially oral communication. Contrary to the claim that translation focuses only on reading and writing, this study presents anecdotal evidence showing that a learner-centered approach to translation can help foreign language students improve their speaking skill through group work, problem-solving, and cooperative learning. To this end, the paper presents practical examples of lexical, structural, textual, and cultural issues that students discussed in their process-oriented Arabic-English-Arabic pedagogical translation courses at the university level. The students were divided into groups of three or four to work together at all stages of the translation process. They spent most of the class time comprehending the source text, translating it, and discussing each other's target versions. In the remaining class time, the whole class discussed a target text translated by any one of the groups. The students were instructed to use English in their group and whole-class deliberations. They were also instructed to use the appropriate language functions, structures, and expressions to achieve objectivity in their arguments. The study calls for further empirical research to verify the usefulness of the proposed learner-centered translation-based technique of teaching speaking展开更多
In part I of this series, experimental investigation in EPFM (elastic-plastic fracture mechanics) had been discussed. In this paper, experimental investigation in LEFM ( linear elastic fracture mechanics) is given...In part I of this series, experimental investigation in EPFM (elastic-plastic fracture mechanics) had been discussed. In this paper, experimental investigation in LEFM ( linear elastic fracture mechanics) is given. Fracture toughness tests had been carried out on three different strength steels, using both through-cracked specimens with different α/W ratio and semi-elliptical cracked specimens with variable crack size and shape. Results show that the fracture toughness KIC increases with decreasing α/W when α/W 〈 0.3 for three-point-bend specimens, and that for α/W 〉 0.3, it is independent of α/W. Shallow crack specimens, both through-cracked and surface-cracked, gave markedly higher values than deeply notched specimens. However, the effect of crack shape on fracture toughness is negligible. Results also show that the LEFM approach to fracture is not tenable for design stresses where αc is often very small, far less than 2.5 ( KIC/σy)^2.展开更多
Macro and micromixing time represent two extreme mixing time scales,which governs the whole hydrodynamics characteristics of the surface aeration systems.With the help of experimental and numerical analysis,simulation...Macro and micromixing time represent two extreme mixing time scales,which governs the whole hydrodynamics characteristics of the surface aeration systems.With the help of experimental and numerical analysis,simulation equation governing those times scale has been presented in the present work.展开更多
Activated carbons (ACs) with different surface properties were prepared from different raw materials. N2 adsorption, pH value, Boehm titration, Temperature-programmed reduction (TPR) and FTIR were employed to char...Activated carbons (ACs) with different surface properties were prepared from different raw materials. N2 adsorption, pH value, Boehm titration, Temperature-programmed reduction (TPR) and FTIR were employed to characterize the pore structure and surface chemical properties of the ACs. The results show that AC from bituminous coal (AC-B) has more meso-pores, higher pH value, more carboxylic groups and basic site than ACs from coconut shell and hawthorn(AC-C, AC-H). Oxygen in the mixture gas has great effect on S02 catalytic oxidation/oxidation ability of AC-B. In the absence of oxygen, the adsorbed SO2 on AC-B is 0.16 mmollg and the conversion ratio of adsorbed S02 to S03 is 22.07~; while in the presence of oxygen, the adsorbed amount of S02 is 0.42 retool/g, and all of the adsorbed S02 was totally converted to SO3. This feature of AC-B is consistent with its higher pH value, basic site and the reaction ability with H2 from TPR. The conversion ratios of S02 absorbed on both AC-C and AC-H were 100%, respectively.展开更多
With the help of Bose operator identities and entangled state representation and based on our previous work.[Phys. Lett. A 325 (2004) 188] we derive some new generalized Bessel equations which also have Bessel funct...With the help of Bose operator identities and entangled state representation and based on our previous work.[Phys. Lett. A 325 (2004) 188] we derive some new generalized Bessel equations which also have Bessel function as their solution. It means that for these intricate higher-order differential equations, we can get Bessel function solutions without using the expatiatory power-series expansion method.展开更多
At present, there are many problems and contradictions such as unclear teaching objective, backward educational ideas, and obsolete teaching contents in the music performance course of the musicology program in the ar...At present, there are many problems and contradictions such as unclear teaching objective, backward educational ideas, and obsolete teaching contents in the music performance course of the musicology program in the art departments of many colleges and universities. To solve these problems and contradictions, high importance should be attached to the art departments of many colleges and universities, and also a series of solutions should be actively sought. Meanwhile, the teaching objective should be made more clearly, the evaluation standards should be improved, and educational ideas should be timely updated. In this paper, many problems exposed in the music performance course of the musicology program in the art departments of many colleges and universities are analyzed, and also a series of feasible countermeasures are proposed.展开更多
Excavation to creativity is one of important means in the teaching process. Comprehensive musicianship course is an experimental teaching method, but also a teaching art form in the music education system. Many achiev...Excavation to creativity is one of important means in the teaching process. Comprehensive musicianship course is an experimental teaching method, but also a teaching art form in the music education system. Many achievements have been made to comprehensive musicianship course since the experimental teaching was established in China. The influence scope of comprehensive musicianship course is constantly expanded in the field of social music teaching, and simultaneously its influencing power is also rising. However, it should be implemented in the process of teaching according to the actual circumstances of the primary and secondary school students in China. In the teaching of comprehensive musicianship course, vocal music performance is applied as the main carrier in form and proceeds very rhythmically in the process of the whole time, and also thoughts and emotions are fully reflected by body languages. It starts from the comprehensive learning, and then is gradually promoted between non-major courses in institutions of higher learning and the music teaching in primary/secondary schools, so that a good teaching effect has been obtained. In comprehensive musicianship course, high importance is attached to the improvement of students' creativity and innovation ability. In this paper, the enlightenment from comprehensive musicianship course on China' s vocal music performance teaching is mainly analyzed.展开更多
The controlling step and the extraction reaction rate equation of zinc extraction from Zn(II)-NH3 solution by using a newly synthesized organic compound, 2-acetyl-3-oxo-dithiobutyric acid-myristyl ester as the zinc ...The controlling step and the extraction reaction rate equation of zinc extraction from Zn(II)-NH3 solution by using a newly synthesized organic compound, 2-acetyl-3-oxo-dithiobutyric acid-myristyl ester as the zinc extractant, were clarified. The effects of agitation speed, specific interfacial area, temperature, extractant concentration and Zn ion concentration on the extraction rate are studied in constant interfacial area cell. The results show that the extraction rate depends on interfacial chemical reaction and diffusion by using this new extraetant to extract zinc, and the apparent activation energy of this extraction reaction is measured as 28.2 kJ/mol, which demonstrates that the extraction reaction is controlled by the mixed-controlled reaction rate. The apparent reaction orders a and b are measured as 1 and 0.38, and the constant k0 is 138.70. So, when extraction conditions are controlled as [HR]=20%-50%, T=0-30℃, N=120-177 r/min and S=72.6-127.5 m-1, the solvent extraction reaction rate can be depicted as v/(mol . m-2 . s-1 ) = 138.7. exp( - 28 206/8.314T ). [Zn 2+ ]r ·[HR ]o0.38.展开更多
This paper makes a detailed analysis of Course Schedules (2013-2014) of College English in four universities of C9 League, which reveals that ESP courses are much less than EGP courses, even in the top universities ...This paper makes a detailed analysis of Course Schedules (2013-2014) of College English in four universities of C9 League, which reveals that ESP courses are much less than EGP courses, even in the top universities in our country, and that the implementation of ESP teaching is hindered for many reasons. Therefore, based on the rapid development of MOOC and the one-size-fits-one guideline of college English teaching, the preferences of ESPMOOC have been illustrated, and the framework to practice trinity ESP teaching mode has been explicitly depicted. The mode refers to the combination of traditional classroom teaching, flipped teaching on aid of MOOC, and autonomous MOOC learning under the condition that ESP teaching group is elaborately set up and 2-band ESP teaching is preferably promoted.展开更多
A new method called mixed Lagrangian and Eulerian method (MILE method) was used to simulate the thermomechanical behavior during continuous casting process of steel YF45MnV. The simulation results are basically in a...A new method called mixed Lagrangian and Eulerian method (MILE method) was used to simulate the thermomechanical behavior during continuous casting process of steel YF45MnV. The simulation results are basically in agreement with the measured data. The delaying period at the beginning of solidification is about 0.1. in square root of solidification time which is agreement with the data in literatures, and shell thickness increases in linear relation to square root of solidification time. The bloom surface temperature decreases gradually as the casting proceeds. The effective stress in the comer is much larger than that in the mid-face. The comer area is the dangerous zone of cracking. The effects of mold flux break temperature on the air gap and hot tearing indicator were also modeled. The model predicts that the bloom surface temperature increases with the increase of the mold flux break temperature, but the heat flux decreases with the increase of the mold flux break temperature. ,The hot tearing indicator is much smaller when the mold flux break temperature is higher.展开更多
A novel chemical liquid reduction process was employed to prepare nanosized Mo-Cu powders. The precipitates were first obtained by adding ammonium heptamolybdate ((NH4)6Mo7024·4H2O) solution into excess hydra...A novel chemical liquid reduction process was employed to prepare nanosized Mo-Cu powders. The precipitates were first obtained by adding ammonium heptamolybdate ((NH4)6Mo7024·4H2O) solution into excess hydrazine hydrate solution, and then mixed the copper chloride solution. The precipitates were subsequently washed, dried, followed by reducing in H2 atmosphere to convert into Mo-Cu composite powders. The composition, morphology and particle size of the Mo-Cu composite powders were characterized by the XRD, SEM and TEM. The effects of the chemical reaction temperature and the magnetic stirring on the morphology of the Mo-Cu powders were also studied. The results show that Mo-Cu powders produced by the chemical liquid reduction process are nearly spherical shape and dispersive distribution state, with particle size ranging from 50 to 100 nm. The chemical reaction temperature and magnetic stirring will change the particle feature of the powders. Because of the Cu3M0209, the reduction process in H2 is the one-stage reduction from the precipitates to the Mo-Cu composite powders.展开更多
基金supported by President Foundation of Chinese Academy of Sciences and National Natural Science Foundation of China under Grant Nos. 10775097 and 10874174
文摘By introducing a fictitious mode to be a counterpart mode of the system mode under review we introduce the entangled state representation (η|, which can arrange master equations of density operators p(t) in quantum statistics as state-vector evolution equations due to the elegant properties of (η|. In this way many master equations (respectively describing damping oscillator, laser, phase sensitive, and phase diffusion processes with different initial density operators) can be concisely solved. Specially, for a damping process characteristic of the decay constant k we find that the matrix element of p(t) at time t in 〈η| representation is proportional to that of the initial po in the decayed entangled state (ηe^-kt| representation, accompanying with a Gaussian damping factor. Thus we have a new insight about the nature of the dissipative process. We also set up the so-called thermo-entangled state representation of density operators, ρ = f(d^2η/π)(η|ρ〉D(η), which is different from all the previous known representations.
文摘In this work we investigated the effect of nitric acid concentration on the pore structure,surface chemistry and liquid phase adsorption of olive stone based activated carbon prepared by mixing process using phosphoric acid and steam as activating agents.Chemicals and textural characterization show that the increase of HNO3concentration increases considerably the total acidic groups but decreases specific surface area and pore volume.The study of adsorption in aqueous solutions of two organics,phenol and methylene blue,on raw and oxidized activated carbon indicates that the treatment of mixed activated carbon with different concentrations of nitric acid improves the adsorbent capacity for methylene blue at HNO3concentrations less or equal to 2 mol·L 1,while it has a negative effect on phenol adsorption.
基金Project(S2598445) supported by the Project for Cooperative R&D between Industry,Academy and Research Institute Funded by the Korea Ministry of SME and Startups in 2018
文摘In this study,we present the characterization of the carbon fibers recovered from the mechanochemical-enhanced recycling of carbon fiber reinforced fibers.The objectives of the study were to investigate the effect of our modified recycling method on the interfacial properties of recovered fibers.The reinforced plastics were recycled;the recycling efficiency was determined and the recovered fibers were sized using 1 wt%and 3 wt%concentration of(3-aminopropyl)triethoxysilane.We characterized the morphologies utilizing the electron spectroscopy for chemical analysis(ESCA),atomic force microscopy(AFM),FTIR-attenuated total reflection(ATR)spectroscopy and scanning electron microscopy(SEM).Although the surface of the fibers had no cracks,there was evidence of contaminations which affected the interfacial properties and the quality of the fibers.Results showed that the trends in the recovered and virgin fibers were similar with an increase in sizing concentration.The results highlighted the perspectives of increasing the quality of recovered fibers after the recycling process.
基金Supported by the High-Tech Research and Development Program of China (863 Program, No. 2001AA633070 2003AA604040)the National Natural Science Foundation of China (No. 40476015).
文摘This study deals with the development of statistical modeling for water wave surface elevation by using a method that combines a dynamic solution with random process statistics. Ocean wave data taken from four NOAA (National Oceanic and Atmospheric Administration) buoys moored in the northeast Pacific were used to validate the model. The results indicated that the nonlinear probability density distribution of ocean wave surface elevation derived from the model described the measurements much better than Gaussian distribution and Longuet-Higgins distribution.
基金supported by CNPq,CAPES,FAPESP(2017/02317-2),FAPESP(2017/11986-5)Shell and the strategic importance of the support given by ANP(Brazil’s National Oil,Natural Gas and Biofuels Agency)through the R&D levy regulation+2 种基金PRH49/UFABC-ANP for the fellowshipthe National Natural Science Foundation of China(NSFC)the Outstanding Talent Program of Shaanxi Province as well as FAPESP(2017/11986-5)
文摘This work describes a simple yet powerful scalable solution chemistry strategy to create back‐contact rich interfaces between substrates such as commercial transparent conducting fluorine‐doped tin oxide coated glass(FTO)and photoactive thin films such as hematite for low‐cost water oxidation reaction.High‐resolution electron microscopy(SEM,TEM,STEM),atomic force microscopy(AFM),elemental chemical mapping(EELS,EDS)and photoelectrochemical(PEC)investigations reveal that the mechanical stress,lattice mismatch,electron energy barrier,and voids between FTO and hematite at the back‐contact interface as well as short‐circuit and detrimental reaction between FTO and the electrolyte can be alleviated by engineering the chemical composition of the precursor solutions,thus increasing the overall efficiency of these low‐cost photoanodes for water oxidation reaction for a clean and sustainable generation of hydrogen from PEC water‐splitting.These findings are of significant importance to improve the charge collection efficiency by minimizing electron‐hole recombination observed at back‐contact interfaces and grain boundaries in mesoporous electrodes,thus improving the overall efficiency and scalability of low‐cost PEC water splitting devices.
文摘In this paper, we conduct analysis on the optimization approaches of contemporary piano education system from the perspective of music knowledge integration. In the process of the piano teaching, teacher and school the training of musicianship as the key point of teaching. This is because the skill can through student plays to display directly, appraises the student performance technique quality an important criterion. However, the student has the excellent adept technique merely also by far insufficient, but also needs the high artistic aesthetic ability, not only need be able to appreciate the piano performance, but must be able to reveal the artistic aesthetic feature in the process of piano performance. Piano education as one of the ways of music education, and other subjects, there is the subject of the universal education as its educational ideas, educational ideas and teaching methods, a direct impact on the generation after generation of the comprehensive quality of education. Under this basis, we propose the new idea on the issues that will be beneficial.
基金financial support from the Basic Fund for the Scientific Research and Operation of Central Universities of China (No. 2009KH10
文摘A series of char samples were derived from pyrolysis of two typical low-rank coals in China (Shengli lig- nite and Shenmu bituminous coal) at low, medium and fast heating rates, respectively, to the same pyrol- ysis temperature 750℃. Then these chars were characterized by means of thermogravimetric analysis and Fourier transform infrared spectrometer with the aim to investigate the influence of heating rate in pyrolysis process on gasification reactivity and surface chemistry of them. Besides, a homogeneous model was used to quantitatively analyze the activation energy of gasification reaction. The results reveal that Shengli lignite and its derived chars behave higher gasification reactivity and have less content of oxygen functional groups than Shenmu coal and chars. Meanwhile, chars derived from Shengli lignite at 50℃/min and Shenmu coal at 200℃/min have the greatest gasification reactivity, respectively. The oxygen functional groups in Shengli lignite are easily thermo-decomposed, and they are less affected by the heating rate, while that in Shenmu coal have a significant change with the variation of heating rate. In addition, there is no good correlation between the change of oxygen functional groups and that of the gasification reactivity of the derived chars from pyrolysis at different heating rates.
文摘Based on the author’s previously obtained results on P and Si forms in southern Bohai Sea surface sediments,this study mainly foucusing on the controlling factors, existence forms, and biogeochemical processes of P and Si showed that the transferable forms of phosphorus in sediments were mainly controlled by the mineralization of organic matters and the reduction of high valence iron; whereas the transferable forms of silicon were possibly controlled by the dissolution and precipitation as well as biochemical processes of living organisms.
文摘This study views pedagogical translation as a means of developing language skills, especially oral communication. Contrary to the claim that translation focuses only on reading and writing, this study presents anecdotal evidence showing that a learner-centered approach to translation can help foreign language students improve their speaking skill through group work, problem-solving, and cooperative learning. To this end, the paper presents practical examples of lexical, structural, textual, and cultural issues that students discussed in their process-oriented Arabic-English-Arabic pedagogical translation courses at the university level. The students were divided into groups of three or four to work together at all stages of the translation process. They spent most of the class time comprehending the source text, translating it, and discussing each other's target versions. In the remaining class time, the whole class discussed a target text translated by any one of the groups. The students were instructed to use English in their group and whole-class deliberations. They were also instructed to use the appropriate language functions, structures, and expressions to achieve objectivity in their arguments. The study calls for further empirical research to verify the usefulness of the proposed learner-centered translation-based technique of teaching speaking
文摘In part I of this series, experimental investigation in EPFM (elastic-plastic fracture mechanics) had been discussed. In this paper, experimental investigation in LEFM ( linear elastic fracture mechanics) is given. Fracture toughness tests had been carried out on three different strength steels, using both through-cracked specimens with different α/W ratio and semi-elliptical cracked specimens with variable crack size and shape. Results show that the fracture toughness KIC increases with decreasing α/W when α/W 〈 0.3 for three-point-bend specimens, and that for α/W 〉 0.3, it is independent of α/W. Shallow crack specimens, both through-cracked and surface-cracked, gave markedly higher values than deeply notched specimens. However, the effect of crack shape on fracture toughness is negligible. Results also show that the LEFM approach to fracture is not tenable for design stresses where αc is often very small, far less than 2.5 ( KIC/σy)^2.
基金Supported by the Department of Science and Technology,Government of India (DSTO717)
文摘Macro and micromixing time represent two extreme mixing time scales,which governs the whole hydrodynamics characteristics of the surface aeration systems.With the help of experimental and numerical analysis,simulation equation governing those times scale has been presented in the present work.
基金support from the National Natural Science Foundation of China (No.50204011)
文摘Activated carbons (ACs) with different surface properties were prepared from different raw materials. N2 adsorption, pH value, Boehm titration, Temperature-programmed reduction (TPR) and FTIR were employed to characterize the pore structure and surface chemical properties of the ACs. The results show that AC from bituminous coal (AC-B) has more meso-pores, higher pH value, more carboxylic groups and basic site than ACs from coconut shell and hawthorn(AC-C, AC-H). Oxygen in the mixture gas has great effect on S02 catalytic oxidation/oxidation ability of AC-B. In the absence of oxygen, the adsorbed SO2 on AC-B is 0.16 mmollg and the conversion ratio of adsorbed S02 to S03 is 22.07~; while in the presence of oxygen, the adsorbed amount of S02 is 0.42 retool/g, and all of the adsorbed S02 was totally converted to SO3. This feature of AC-B is consistent with its higher pH value, basic site and the reaction ability with H2 from TPR. The conversion ratios of S02 absorbed on both AC-C and AC-H were 100%, respectively.
基金The project supported by National Natural Science Foundation of China and the President Foundation of the Chinese Academy of Sciences
文摘With the help of Bose operator identities and entangled state representation and based on our previous work.[Phys. Lett. A 325 (2004) 188] we derive some new generalized Bessel equations which also have Bessel function as their solution. It means that for these intricate higher-order differential equations, we can get Bessel function solutions without using the expatiatory power-series expansion method.
文摘At present, there are many problems and contradictions such as unclear teaching objective, backward educational ideas, and obsolete teaching contents in the music performance course of the musicology program in the art departments of many colleges and universities. To solve these problems and contradictions, high importance should be attached to the art departments of many colleges and universities, and also a series of solutions should be actively sought. Meanwhile, the teaching objective should be made more clearly, the evaluation standards should be improved, and educational ideas should be timely updated. In this paper, many problems exposed in the music performance course of the musicology program in the art departments of many colleges and universities are analyzed, and also a series of feasible countermeasures are proposed.
文摘Excavation to creativity is one of important means in the teaching process. Comprehensive musicianship course is an experimental teaching method, but also a teaching art form in the music education system. Many achievements have been made to comprehensive musicianship course since the experimental teaching was established in China. The influence scope of comprehensive musicianship course is constantly expanded in the field of social music teaching, and simultaneously its influencing power is also rising. However, it should be implemented in the process of teaching according to the actual circumstances of the primary and secondary school students in China. In the teaching of comprehensive musicianship course, vocal music performance is applied as the main carrier in form and proceeds very rhythmically in the process of the whole time, and also thoughts and emotions are fully reflected by body languages. It starts from the comprehensive learning, and then is gradually promoted between non-major courses in institutions of higher learning and the music teaching in primary/secondary schools, so that a good teaching effect has been obtained. In comprehensive musicianship course, high importance is attached to the improvement of students' creativity and innovation ability. In this paper, the enlightenment from comprehensive musicianship course on China' s vocal music performance teaching is mainly analyzed.
基金Foundation item: Project(51174240) supported by the National Natural Science Foundation of China Project(2006BA02B04-4-2) supported by the National Eleventh Five-Year Research Program of China Project(20100908) supported by Scientific and Industrial Research Organisation of Guangdong Province, China
文摘The controlling step and the extraction reaction rate equation of zinc extraction from Zn(II)-NH3 solution by using a newly synthesized organic compound, 2-acetyl-3-oxo-dithiobutyric acid-myristyl ester as the zinc extractant, were clarified. The effects of agitation speed, specific interfacial area, temperature, extractant concentration and Zn ion concentration on the extraction rate are studied in constant interfacial area cell. The results show that the extraction rate depends on interfacial chemical reaction and diffusion by using this new extraetant to extract zinc, and the apparent activation energy of this extraction reaction is measured as 28.2 kJ/mol, which demonstrates that the extraction reaction is controlled by the mixed-controlled reaction rate. The apparent reaction orders a and b are measured as 1 and 0.38, and the constant k0 is 138.70. So, when extraction conditions are controlled as [HR]=20%-50%, T=0-30℃, N=120-177 r/min and S=72.6-127.5 m-1, the solvent extraction reaction rate can be depicted as v/(mol . m-2 . s-1 ) = 138.7. exp( - 28 206/8.314T ). [Zn 2+ ]r ·[HR ]o0.38.
文摘This paper makes a detailed analysis of Course Schedules (2013-2014) of College English in four universities of C9 League, which reveals that ESP courses are much less than EGP courses, even in the top universities in our country, and that the implementation of ESP teaching is hindered for many reasons. Therefore, based on the rapid development of MOOC and the one-size-fits-one guideline of college English teaching, the preferences of ESPMOOC have been illustrated, and the framework to practice trinity ESP teaching mode has been explicitly depicted. The mode refers to the combination of traditional classroom teaching, flipped teaching on aid of MOOC, and autonomous MOOC learning under the condition that ESP teaching group is elaborately set up and 2-band ESP teaching is preferably promoted.
基金Project(51174020) supported by the National Natural Science Foundation of China
文摘A new method called mixed Lagrangian and Eulerian method (MILE method) was used to simulate the thermomechanical behavior during continuous casting process of steel YF45MnV. The simulation results are basically in agreement with the measured data. The delaying period at the beginning of solidification is about 0.1. in square root of solidification time which is agreement with the data in literatures, and shell thickness increases in linear relation to square root of solidification time. The bloom surface temperature decreases gradually as the casting proceeds. The effective stress in the comer is much larger than that in the mid-face. The comer area is the dangerous zone of cracking. The effects of mold flux break temperature on the air gap and hot tearing indicator were also modeled. The model predicts that the bloom surface temperature increases with the increase of the mold flux break temperature, but the heat flux decreases with the increase of the mold flux break temperature. ,The hot tearing indicator is much smaller when the mold flux break temperature is higher.
基金Project(51274246) supported by the National Natural Science Foundation of China
文摘A novel chemical liquid reduction process was employed to prepare nanosized Mo-Cu powders. The precipitates were first obtained by adding ammonium heptamolybdate ((NH4)6Mo7024·4H2O) solution into excess hydrazine hydrate solution, and then mixed the copper chloride solution. The precipitates were subsequently washed, dried, followed by reducing in H2 atmosphere to convert into Mo-Cu composite powders. The composition, morphology and particle size of the Mo-Cu composite powders were characterized by the XRD, SEM and TEM. The effects of the chemical reaction temperature and the magnetic stirring on the morphology of the Mo-Cu powders were also studied. The results show that Mo-Cu powders produced by the chemical liquid reduction process are nearly spherical shape and dispersive distribution state, with particle size ranging from 50 to 100 nm. The chemical reaction temperature and magnetic stirring will change the particle feature of the powders. Because of the Cu3M0209, the reduction process in H2 is the one-stage reduction from the precipitates to the Mo-Cu composite powders.