With the rapid growth of cloud computing,the number of data centers(DCs)continuously increases,leading to a high-energy consumption dilemma.Cooling,apart from IT equipment,represents the largest energy consumption in ...With the rapid growth of cloud computing,the number of data centers(DCs)continuously increases,leading to a high-energy consumption dilemma.Cooling,apart from IT equipment,represents the largest energy consumption in DCs.Passive design(PD)and active design(AD)are two important approaches in architectural design to reduce energy consumption.However,for DC cooling,few studies have summarized AD,and there are almost no studies on PD.Based on existing international research(2005-2024),this paper summarizes the current state of cooling strategies for DCs.PD encompasses floors,ceilings,and layout and zoning of racks.Additionally,other passive strategies not yet studied in DCs are critically examined.AD includes air,liquid,free,and two-phase cooling.This paper systematically compares the performance of different AD technologies on various KPIs,including energy,economic,and environmental indicators.This paper also explores the application of different cooling design strategies through best-practice examples and presents advanced algorithms for energy management in operational DCs.This study reveals that free cooling is widely employed,with Artificial Neural Networks emerging as the most popular algorithm for managing cooling energy.Finally,this paper suggests four future directions for reducing cooling energy in DCs,with a focus on the development of passive strategies.This paper provides an overview and guide to DC energy-consumption issues,emphasizes the importance of implementing passive and active design strategies to reduce DC cooling energy consumption,and provides directions and references for future energy-efficient DC designs.展开更多
A design problem with deficient information is generally described as wicked or ill-defined.The information insufficiency leaves designers with loose settings,free environments,and a lack of strict boundaries,which pr...A design problem with deficient information is generally described as wicked or ill-defined.The information insufficiency leaves designers with loose settings,free environments,and a lack of strict boundaries,which provides them with more opportunities to facilitate innovation.Therefore,to capture the opportunity behind the uncertainty of a design problem,this study models an innovative design as a composite solving process,where the problem is clarified and resolved from fuzziness to satisfying solutions by interplay among design problems,knowledge,and solutions.Additionally,a triple-helix structured model for the innovative product design process is proposed based on the co-evolution of the problem,solution,and knowledge spaces,to provide designers with a distinct design strategy and method for innovative design.The three spaces interact and co-evolve through iterative mappings,including problem structuring,knowledge expansion,and solution generation.The mappings carry the information processing and decision-making activities of the design,and create the path to satisfying solutions.Finally,a case study of a reactor coolant flow distribution device is presented to demonstrate the practicability of this model and the method for innovative product design.展开更多
The presence of hydroxyl groups at the C4 and C7 positions in coumarin backbone has been proposed as a potential modification site for providing excellent bioactivity according to previous studies. A series of novel c...The presence of hydroxyl groups at the C4 and C7 positions in coumarin backbone has been proposed as a potential modification site for providing excellent bioactivity according to previous studies. A series of novel coumarin derivatives were rationally designed and synthesized by use of a complex catalytic system for a targeted modification at the above sites. These derivatives were assayed for nematicidal activity. As predicted, the derivatization enhanced the activity of the coumarins against five nematodes.Compounds 7b, 9a, 10 c and 11 c showed significant strong nematicidal broad spectrum activity against all tested nematodes. Compound 10 c was the most effective with the lowest LC50 values against Meloidogyne incognita（5.1 mmol/L）, Ditylenchus destructor（3.7 mmol/L）, Bursaphelenchus mucronatus（6.4 mmol/L）, Bursaphelenchus B. xylophilus（2.5 mmol/L） and Aphelenchoides besseyi（3.1 mmol/L）,respectively. A brief investigation on the structure–activity relationships（SAR） revealed that the targeted modification by a C7 hydroxyl was optimum compared with that of a C4 hydroxyl and that the coupling chain length was crucial for the nematicidal activity.展开更多
The ship design process model is the basis for developing the ship collaborative design system under network environment.According to the characteristics of the ship design, a method for dividing the ship design proce...The ship design process model is the basis for developing the ship collaborative design system under network environment.According to the characteristics of the ship design, a method for dividing the ship design process into three layers is pat forward, that is project layer, design task layer and design activity layer, then the formalized definitions of the ship design process model, the decomposing principles of the ship design process and the architecture of the ship collaborative design (SDPM) system are presented. This method simplifies the activity network, makes the optimization and adjustment of the design plan convenient and also makes the design process easier to control and change, at last the architecture of the ship collaborative design system is discussed.展开更多
A digital model is presented for the purpose of design, manufacture and measurement of hypoid gear, based on the non-uniform rational B-spline surface （NURBS） method. The digital model and the function-oriented acti...A digital model is presented for the purpose of design, manufacture and measurement of hypoid gear, based on the non-uniform rational B-spline surface （NURBS） method. The digital model and the function-oriented active design technique are combined to form a new design method for hypoid gears. The method is well adaptable to CNC bevel gear cutting machines and CNC-controlled gear inspection machines, and can be used to create the initial machine tool cutting location data or program measurement path. The presented example verifies the method is correct.展开更多
MOOC has become the topic of the education reform in recent years. From activity theory point of view, meaningful learning is an active, conscious, constructive, and socially medicated practice that includes reciproca...MOOC has become the topic of the education reform in recent years. From activity theory point of view, meaningful learning is an active, conscious, constructive, and socially medicated practice that includes reciprocal intention-action-reflection activities. This paper aims to try to give a MOOC learning activity design model in grammar teaching which tries to offer a reference for the MOOC teaching in grammar lesson.展开更多
The task activity in the post-task stage is mainly to enable the students clearly aware of their own language learning process in the existing problems and effectively solve them through the ＂do-it-again＂ , language...The task activity in the post-task stage is mainly to enable the students clearly aware of their own language learning process in the existing problems and effectively solve them through the ＂do-it-again＂ , language focus and other activities, and at the same time the focus of this lesson, difficulties are more clear and clear. It can be said that post-task activities play a vital role in highlighting priorities, breaking through difficulties, and achieving effective goals for teaching goals. The design of the activities in the post-task stage is to complete the task and language focus together, reflecting the distinctive characteristics of task-based teaching. The design of the activities in the post-task stage can be achieved through evaluation, language focus, and extra-curricular activities.展开更多
There are many problems in English Vocabulary Teaching in rural primary schools. In order to solve these problems, create a situation suitable for rural children's English learning, more in line with rural childre...There are many problems in English Vocabulary Teaching in rural primary schools. In order to solve these problems, create a situation suitable for rural children's English learning, more in line with rural children’s life experience, and design activities to improve learning interest and efficiency, three English teachers from two rural primary schools in Jianyang City, Sichuan Province (Pingwu Jiuyi school and Pingxi Jiuyi school) conducted the following research: 1. Study two rural schools, grade 3-5, and nine class farmers English vocabulary learning of village students. 2. Combined with the materials about the creation of English situation and activity design in primary schools, we discuss how to create English vocabulary activity teaching situation and activity plan suitable for rural children after studying the teaching materials. Then, using the method of collective lesson preparation, this paper sorts out the vocabulary teaching plan for grade 3-5 and puts it into practice. 3. Through the data analysis of the experimental class and the control class, it is concluded that these programs can effectively improve the interest and effect of rural primary school English learning.展开更多
Edutainment,in the kindergarten education stage,emphasizes the game as the basic activity and combines the content of education with the form of the game,thus it also forms the educational method of gamification teach...Edutainment,in the kindergarten education stage,emphasizes the game as the basic activity and combines the content of education with the form of the game,thus it also forms the educational method of gamification teaching.Through investigation and analysis,it is found that the current kindergarten game activity design has the problem of improper combination of educational content and game form.The current kindergarten game activity design has problems such as stereotypes,children’s lack of active learning opportunities in activities,teachers’insufficient theoretical understanding,inappropriate teacher guidance methods,and so on.Embodied cognition theory attaches importance to the important role of the body in the development of cognition,provides new guidance for classroom teaching,and opens up a new path for classroom teaching reform.Based on the perspective of embodied cognition theory,the concept of body and mind integration should be adhered to in kindergarten teaching with games as the basic activity,experiential teaching situation should be created,children’s subjective experience should be respected,and games and interactions should be designed to promote children’s physical and mental participation,thus laying a foundation for the realization of children’s individual freedom,autonomy,and all-round development.Therefore,this paper aims at the existing problems in the current kindergarten gamification teaching and discusses the design strategy of children’s game activities based on embodied cognition theory.展开更多
With the deepening advancement of the integration of production and education,higher vocational preschool education majors need to accurately align with industry demands to cultivate applied talents.The course"Ki...With the deepening advancement of the integration of production and education,higher vocational preschool education majors need to accurately align with industry demands to cultivate applied talents.The course"Kindergarten Activity Design and Guidance"is a core professional course offered by preschool education majors.It helps students establish correct views on children and education in kindergartens,equips them with the ability to design and organize educational activities in the five major areas of kindergartens,and achieves a seamless connection between students and future teachers,as well as between schools and kindergartens.Its teaching effect directly affects the effectiveness of talent training.Therefore,constantly reflecting on and exploring curriculum teaching is of great significance for the construction of preschool education majors and the professional growth of students.The research results can provide theoretical reference and practical experience for the reform of similar courses in higher vocational preschool education majors.展开更多
The flipped classroom is an emerging teaching mode which is originated from the United States and is now prevalent in many countries. It is helpful to build a more harmonious relationship between the teachers and the ...The flipped classroom is an emerging teaching mode which is originated from the United States and is now prevalent in many countries. It is helpful to build a more harmonious relationship between the teachers and the students, to enhance the students＇ self-study ability, to create a favorable learning environment, to realize the individualized teaching in class, and to improve the students＇ English ability. The study focuses on the college English classroom in China. The author tries to prove that the flipped classroom is a helpful way to improve the teaching and learning effect of college English classroom. A teaching procedure for the flipped college English classroom is designed in the hope of changing the current college English teaching condition.展开更多
The application of corpus in language teaching develops more extensive than before,and corpus for language study not only provides unprecedentedly extensive speech material,but also makes the traditional language rese...The application of corpus in language teaching develops more extensive than before,and corpus for language study not only provides unprecedentedly extensive speech material,but also makes the traditional language research transform from sam⁃plings through introspection,building by examples or induced asking into the methods of surveying sampling with the real materi⁃als.This paper will explore the role of corpus on the foreign language teaching from the following two aspects:teaching design and activities,grammar teaching.展开更多
Alkaline pretreatment is an effective technology to disintegrate sewage sludge, where alkali dosage and sludge concentration are two important factors. p H value or alkali concentration is usually adjusted in order to...Alkaline pretreatment is an effective technology to disintegrate sewage sludge, where alkali dosage and sludge concentration are two important factors. p H value or alkali concentration is usually adjusted in order to determine a proper dosage of alkali. Our work has found that this is not a good strategy. A new parameter, the ratio of alkali to sludge(Ra/s), is more sensitive in controlling the alkali dosage. The sludge concentration Csand retention time t are two other important factors to consider. The validity of these arguments is confirmed with modeling and experiments. The individual effect of Ra/s, Csand t was studied separately. Then the combined effect of these three factors was evaluated. The sludge disintegration degree of 44.7% was achieved with the optimized factors. Furthermore, an alkaline-microwave combined pretreatment process was carried out under these optimized conditions. A high disintegration degree of 62.3% was achieved while the energy consumption of microwave was much lower than previously reported.展开更多
Homogenous charge compression ignition （HCCI） engines feature high thermal efficiency and ultralow emissions compared to gasoline engines. However, unlike SI engines, HCCI combustion does not have a direct way to tr...Homogenous charge compression ignition （HCCI） engines feature high thermal efficiency and ultralow emissions compared to gasoline engines. However, unlike SI engines, HCCI combustion does not have a direct way to trigger the in-cylinder combustion. Therefore, gasoline HCCI combustion is facing challenges in the control of ignition and, combustion, and operational range extension. In this paper, an active fuel design concept was proposed to explore a potential pathway to optimize the HCCI engine combustion and broaden its operational range. The active fuel design concept was realized by real time control of dual-fuel （gasoline and n-heptane） port injection, with exhaust gas recirculation （EGR） rate and intake temperature adjusted. It was found that the cylinder- to-cylinder variation in HCCI combustion could be effectively reduced by the optimization in fuel injection proportion, and that the rapid transition process from SI to HCCI could be realized. The active fuel design technology could significantly increase the adaptability of HCCI combustion to increased EGR rate and reduced intake temperature. Active fuel design was shown to broaden the operational HCCI load to 9.3 bar indicated mean effective pressure （IMEP）. HCCI operation was used by up to 70% of the SI mode load while reducing fuel consumption and nitrogen oxides emissions. Therefore, the active fuel design technology could manage the right fuel for clean engine combustion, and provide a potential pathway for engine fuel diversification and future engine concept.展开更多
In this paper the basic principle and the problems meriting attention in the design and application of active ear defenders are discussed quantitatively. A feasible structure and its experimental results are given. It...In this paper the basic principle and the problems meriting attention in the design and application of active ear defenders are discussed quantitatively. A feasible structure and its experimental results are given. It is illustrated that the chief significance of ' active ' is to change the mechanical impedance of the ear defender accordingly, and because of this mechanism, the noise attenuation effectiveness in the low frequency range is improved.展开更多
Metal-organic frameworks(MOFs)are porous organic-inorganic coordination materials with numerous active sites,enabling them to mimic the properties of natural enzymes and making them highly promising for sensing applic...Metal-organic frameworks(MOFs)are porous organic-inorganic coordination materials with numerous active sites,enabling them to mimic the properties of natural enzymes and making them highly promising for sensing applications.This review provides a detailed overview of recent advancements in leveraging MOFs for the design of catalytic active sites in nanozymes.MOFs utilize metal ions and organic ligands as active centers for biomimetic catalysis,while their porous frameworks efficiently bind and stabilize multiple vip active units.Furthermore,MOFs can undergo chemical transformations to produce derivatives such as porous carbon materials and nanostructured metal compounds,enhancing their catalytic performance and broadening their applications as nanozymes.This review also explores the progress of MOF-based nanozymes across various catalytic modes in analytical sensing,highlighting their ability to significantly improve detection sensitivity,selectivity,and range.Additionally,the critical role of diverse active sites in sensing processes is emphasized,with attention to the design and synthesis strategies required to optimize the performance of MOF nanozymes.Finally,the review discusses future prospects for the development of MOF nanozymes and outlines key challenges that must be addressed to advance this field.展开更多
The importance of crystallite size control and direct synthesis of materials with desirable properties is broadly applicable for the rational design and development of new active materials for energy storage.Recently,...The importance of crystallite size control and direct synthesis of materials with desirable properties is broadly applicable for the rational design and development of new active materials for energy storage.Recently,the use of nanoparticles and crystallite size control has redefined electrode design strategies,due in part to the large surface area/volume ratios providing more pathways for ion movement within the bulk electrode.This review is structured primarily as a case study,where reports involving a specific densely structured iron oxide,magnetite,Fe_(3)O_(4),and its use as an electrode in LIBs are used as examples.Due to the high theoretical capacity(924 mA h g^(−1)),and opportunity for implementation of a low cost electrode material,magnetite was selected as the model material for this review.Notably,crystallite size,morphology,and electrode heterostructure can all play a critical role in battery relevant electrochemistry,particularly for crystallographically dense materials such as Fe_(3)O_(4).Several examples of Fe_(3)O_(4)based composites are described,incorporating different types of conductive materials such as carbons as part of the structure.Additionally,this review also provides a brief introduction to a newer iron oxide based material with a 2D layered structure,silver ferrite,where crystallite size control was synthetically achieved.By focusing on two specific iron oxide based nanoscale inorganic materials,this review highlights and distinguishes the contributions of electroactive material crystallite size,morphology and electrode heterostructure to electrochemical behavior,facilitating the future development of next generation of battery electrodes.展开更多
Recently,controllable photoluminescence tuning by devising a solid solution framework,adjusting the valence mixing of Eu^(2+)/Eu^(3+)and designing efficient energy transfer between activator ions has been extensively ...Recently,controllable photoluminescence tuning by devising a solid solution framework,adjusting the valence mixing of Eu^(2+)/Eu^(3+)and designing efficient energy transfer between activator ions has been extensively investigated and reported due to its significant advantages in the improvement and regulation of the luminescence performances of white light-emitting diodes(W-LEDs).In this study,we designed a series of novel Eu^(2+)-doped(1-x)Ca_(3)(PO_(4))_(2)-xCa_(9)Y(PO_(4))_(7)(x=0-1.0)isostructural solid solution phosphors with aβ-Ca_(3)(PO_(4))_(2)-type structure,and powder samples were prepared via the traditional hightemperature solid-state reaction process.The crystal field variation around the Eu^(2+)ions causes superposition of linear luminescence and induces optical property tuning with a change in the solid solution ratio,x,values.Besides the high-energy emission peak at 418 nm in Ca_(3)(PO_(4))_(2):0.03Eu^(2+),another lowenergy emission peak at 486 nm was observed with the formation of the solid solution.Moreover,the corresponding high-energy emission peaks shifted from 418 to 430 nm,and the luminescence intensity of the low-energy emission at 486 nm increased with an increase in x,which was attributed to the combined effect of crystal field splitting of the local lattice and superposition of linear luminescence.In addition,tunable emission across the whole white light region could be realized by constructing a solid solution and adjusting the overall Eu concentration in(1-x)Ca_(3)(PO_(4))_(2)-xCa_(9)Y(PO_(4))_(7):Eu(x=0.5,0.7,0.9,and 1.0),and the corresponding luminescence mechanisms have been proposed and discussed in detail.In the pursuit of precise color tuning,we also tested the Eu^(2+)→Mn^(2+)energy transfer in different compositions(x=0.2,0.5,0.7,and 0.9)of the solid solution phosphors,and successive emission tuning from the blue and cyan range and then the red range was successfully achieved.Finally,the temperaturedependent photoluminescence and decay time were revealed systematically,and the corresponding mechanisms for the thermal quenching behavior have been discussed.This study provides a new perspective for color tuning originating from the simultaneous isostructural solid solution,valence mixing of Eu^(2+)/Eu^(3+)and efficient energy transfer.展开更多
Spectral modification is crucial for luminescent materials.A variety of strategies have been proposed in the literature,including the selection of activator ions with characteristic electron configurations,the modific...Spectral modification is crucial for luminescent materials.A variety of strategies have been proposed in the literature,including the selection of activator ions with characteristic electron configurations,the modification of the local crystal field,and the design of an emissive center pair and energy transfer.Eu^(2+)-activated haloapatites are considered as candidates for phosphor converted light emitting devices due to their excellent stabilities,easy preparation,and high efficiency.In this work,single-phased,single-doped(Ba,Sr)_(5)(PO_(4))_(3)Br:Eu^(2+)is selected and multiple approaches are applied,leading to multicolor tunabilities of the phosphors,including a crystal field strength controlled spectral shift,occupancy selectivity induced spectral saltation,defect-driven color tunability,and irradiation dependent dynamic chromaticity.In the high Eu^(2+)concentration doped Ba_(5−m)Sr_(m)(PO_(4))_(3)Br phosphor,the main emission band shifts from 448 to 452 nm with increasing Sr^(2+)/Ba^(2+)ratio,and a second emission band around the green region uplifts in the binary metal solid solution phosphors,leading to variable emission colors from blue to cyan under near UV excitation.Moreover,oxygen vacancy(VO)defects formed under synthetic reducing conditions endow the bromoapatites with bright self-activated luminescence.In the low Eu^(2+)concentration doped Ba_(2)Sr_(3)(PO_(4))_(3)Br,the combination of the broad yellow-green emission from VO and bluish emission from Eu^(2+)contributes to a full spectrum feature.The gradual increase of Eu^(2+)concentrations regulates the tunable emission from yellow-green,through white,to blue under short UV excitation.Furthermore,due to the different absorption preferences of these two centers,Ba_(2)Sr_(3)(PO_(4))_(3)Br:0.01Eu^(2+)shows white light emission under 254 nm irradiation while blue emission when exposed to 365 nm irradiation.The materials with multicolor luminescence show promising versatile applications in lighting,biological detection and anti-counterfeiting.The cooperative effects of multiple strategies provide a promising approach to regulate the optical properties of inorganic phosphors.展开更多
文摘With the rapid growth of cloud computing,the number of data centers(DCs)continuously increases,leading to a high-energy consumption dilemma.Cooling,apart from IT equipment,represents the largest energy consumption in DCs.Passive design(PD)and active design(AD)are two important approaches in architectural design to reduce energy consumption.However,for DC cooling,few studies have summarized AD,and there are almost no studies on PD.Based on existing international research(2005-2024),this paper summarizes the current state of cooling strategies for DCs.PD encompasses floors,ceilings,and layout and zoning of racks.Additionally,other passive strategies not yet studied in DCs are critically examined.AD includes air,liquid,free,and two-phase cooling.This paper systematically compares the performance of different AD technologies on various KPIs,including energy,economic,and environmental indicators.This paper also explores the application of different cooling design strategies through best-practice examples and presents advanced algorithms for energy management in operational DCs.This study reveals that free cooling is widely employed,with Artificial Neural Networks emerging as the most popular algorithm for managing cooling energy.Finally,this paper suggests four future directions for reducing cooling energy in DCs,with a focus on the development of passive strategies.This paper provides an overview and guide to DC energy-consumption issues,emphasizes the importance of implementing passive and active design strategies to reduce DC cooling energy consumption,and provides directions and references for future energy-efficient DC designs.
基金Supported by National Natural Science Foundation of China(Grant No.51435011).
文摘A design problem with deficient information is generally described as wicked or ill-defined.The information insufficiency leaves designers with loose settings,free environments,and a lack of strict boundaries,which provides them with more opportunities to facilitate innovation.Therefore,to capture the opportunity behind the uncertainty of a design problem,this study models an innovative design as a composite solving process,where the problem is clarified and resolved from fuzziness to satisfying solutions by interplay among design problems,knowledge,and solutions.Additionally,a triple-helix structured model for the innovative product design process is proposed based on the co-evolution of the problem,solution,and knowledge spaces,to provide designers with a distinct design strategy and method for innovative design.The three spaces interact and co-evolve through iterative mappings,including problem structuring,knowledge expansion,and solution generation.The mappings carry the information processing and decision-making activities of the design,and create the path to satisfying solutions.Finally,a case study of a reactor coolant flow distribution device is presented to demonstrate the practicability of this model and the method for innovative product design.
基金the National Natural Science Foundation of China(Nos.31070386,21302195 and 31300290)135 Key Cultivation Program of the Chinese Academy of Sciencesthe Province-Academy Cooperation Program of Henan Province of China(No.102106000021)for financial support
文摘The presence of hydroxyl groups at the C4 and C7 positions in coumarin backbone has been proposed as a potential modification site for providing excellent bioactivity according to previous studies. A series of novel coumarin derivatives were rationally designed and synthesized by use of a complex catalytic system for a targeted modification at the above sites. These derivatives were assayed for nematicidal activity. As predicted, the derivatization enhanced the activity of the coumarins against five nematodes.Compounds 7b, 9a, 10 c and 11 c showed significant strong nematicidal broad spectrum activity against all tested nematodes. Compound 10 c was the most effective with the lowest LC50 values against Meloidogyne incognita（5.1 mmol/L）, Ditylenchus destructor（3.7 mmol/L）, Bursaphelenchus mucronatus（6.4 mmol/L）, Bursaphelenchus B. xylophilus（2.5 mmol/L） and Aphelenchoides besseyi（3.1 mmol/L）,respectively. A brief investigation on the structure–activity relationships（SAR） revealed that the targeted modification by a C7 hydroxyl was optimum compared with that of a C4 hydroxyl and that the coupling chain length was crucial for the nematicidal activity.
基金Supported by Harbin Engineering University Fund Project (NO. HEUFT04006) Heilongjiang Scientific Research Project (NO. WC05A01)
文摘The ship design process model is the basis for developing the ship collaborative design system under network environment.According to the characteristics of the ship design, a method for dividing the ship design process into three layers is pat forward, that is project layer, design task layer and design activity layer, then the formalized definitions of the ship design process model, the decomposing principles of the ship design process and the architecture of the ship collaborative design (SDPM) system are presented. This method simplifies the activity network, makes the optimization and adjustment of the design plan convenient and also makes the design process easier to control and change, at last the architecture of the ship collaborative design system is discussed.
基金This project is supported by National Natural Science Foundation of China (NO.59775009)
文摘A digital model is presented for the purpose of design, manufacture and measurement of hypoid gear, based on the non-uniform rational B-spline surface （NURBS） method. The digital model and the function-oriented active design technique are combined to form a new design method for hypoid gears. The method is well adaptable to CNC bevel gear cutting machines and CNC-controlled gear inspection machines, and can be used to create the initial machine tool cutting location data or program measurement path. The presented example verifies the method is correct.
文摘MOOC has become the topic of the education reform in recent years. From activity theory point of view, meaningful learning is an active, conscious, constructive, and socially medicated practice that includes reciprocal intention-action-reflection activities. This paper aims to try to give a MOOC learning activity design model in grammar teaching which tries to offer a reference for the MOOC teaching in grammar lesson.
文摘The task activity in the post-task stage is mainly to enable the students clearly aware of their own language learning process in the existing problems and effectively solve them through the ＂do-it-again＂ , language focus and other activities, and at the same time the focus of this lesson, difficulties are more clear and clear. It can be said that post-task activities play a vital role in highlighting priorities, breaking through difficulties, and achieving effective goals for teaching goals. The design of the activities in the post-task stage is to complete the task and language focus together, reflecting the distinctive characteristics of task-based teaching. The design of the activities in the post-task stage can be achieved through evaluation, language focus, and extra-curricular activities.
文摘There are many problems in English Vocabulary Teaching in rural primary schools. In order to solve these problems, create a situation suitable for rural children's English learning, more in line with rural children’s life experience, and design activities to improve learning interest and efficiency, three English teachers from two rural primary schools in Jianyang City, Sichuan Province (Pingwu Jiuyi school and Pingxi Jiuyi school) conducted the following research: 1. Study two rural schools, grade 3-5, and nine class farmers English vocabulary learning of village students. 2. Combined with the materials about the creation of English situation and activity design in primary schools, we discuss how to create English vocabulary activity teaching situation and activity plan suitable for rural children after studying the teaching materials. Then, using the method of collective lesson preparation, this paper sorts out the vocabulary teaching plan for grade 3-5 and puts it into practice. 3. Through the data analysis of the experimental class and the control class, it is concluded that these programs can effectively improve the interest and effect of rural primary school English learning.
文摘Edutainment,in the kindergarten education stage,emphasizes the game as the basic activity and combines the content of education with the form of the game,thus it also forms the educational method of gamification teaching.Through investigation and analysis,it is found that the current kindergarten game activity design has the problem of improper combination of educational content and game form.The current kindergarten game activity design has problems such as stereotypes,children’s lack of active learning opportunities in activities,teachers’insufficient theoretical understanding,inappropriate teacher guidance methods,and so on.Embodied cognition theory attaches importance to the important role of the body in the development of cognition,provides new guidance for classroom teaching,and opens up a new path for classroom teaching reform.Based on the perspective of embodied cognition theory,the concept of body and mind integration should be adhered to in kindergarten teaching with games as the basic activity,experiential teaching situation should be created,children’s subjective experience should be respected,and games and interactions should be designed to promote children’s physical and mental participation,thus laying a foundation for the realization of children’s individual freedom,autonomy,and all-round development.Therefore,this paper aims at the existing problems in the current kindergarten gamification teaching and discusses the design strategy of children’s game activities based on embodied cognition theory.
文摘With the deepening advancement of the integration of production and education,higher vocational preschool education majors need to accurately align with industry demands to cultivate applied talents.The course"Kindergarten Activity Design and Guidance"is a core professional course offered by preschool education majors.It helps students establish correct views on children and education in kindergartens,equips them with the ability to design and organize educational activities in the five major areas of kindergartens,and achieves a seamless connection between students and future teachers,as well as between schools and kindergartens.Its teaching effect directly affects the effectiveness of talent training.Therefore,constantly reflecting on and exploring curriculum teaching is of great significance for the construction of preschool education majors and the professional growth of students.The research results can provide theoretical reference and practical experience for the reform of similar courses in higher vocational preschool education majors.
文摘The flipped classroom is an emerging teaching mode which is originated from the United States and is now prevalent in many countries. It is helpful to build a more harmonious relationship between the teachers and the students, to enhance the students＇ self-study ability, to create a favorable learning environment, to realize the individualized teaching in class, and to improve the students＇ English ability. The study focuses on the college English classroom in China. The author tries to prove that the flipped classroom is a helpful way to improve the teaching and learning effect of college English classroom. A teaching procedure for the flipped college English classroom is designed in the hope of changing the current college English teaching condition.
文摘The application of corpus in language teaching develops more extensive than before,and corpus for language study not only provides unprecedentedly extensive speech material,but also makes the traditional language research transform from sam⁃plings through introspection,building by examples or induced asking into the methods of surveying sampling with the real materi⁃als.This paper will explore the role of corpus on the foreign language teaching from the following two aspects:teaching design and activities,grammar teaching.
基金the National Natural Science Foundation of China(51078234)Shenzhen R&D fund(JCYJ20140418193546101)Shenzhen University R&D fund(T201203)
文摘Alkaline pretreatment is an effective technology to disintegrate sewage sludge, where alkali dosage and sludge concentration are two important factors. p H value or alkali concentration is usually adjusted in order to determine a proper dosage of alkali. Our work has found that this is not a good strategy. A new parameter, the ratio of alkali to sludge(Ra/s), is more sensitive in controlling the alkali dosage. The sludge concentration Csand retention time t are two other important factors to consider. The validity of these arguments is confirmed with modeling and experiments. The individual effect of Ra/s, Csand t was studied separately. Then the combined effect of these three factors was evaluated. The sludge disintegration degree of 44.7% was achieved with the optimized factors. Furthermore, an alkaline-microwave combined pretreatment process was carried out under these optimized conditions. A high disintegration degree of 62.3% was achieved while the energy consumption of microwave was much lower than previously reported.
文摘Homogenous charge compression ignition （HCCI） engines feature high thermal efficiency and ultralow emissions compared to gasoline engines. However, unlike SI engines, HCCI combustion does not have a direct way to trigger the in-cylinder combustion. Therefore, gasoline HCCI combustion is facing challenges in the control of ignition and, combustion, and operational range extension. In this paper, an active fuel design concept was proposed to explore a potential pathway to optimize the HCCI engine combustion and broaden its operational range. The active fuel design concept was realized by real time control of dual-fuel （gasoline and n-heptane） port injection, with exhaust gas recirculation （EGR） rate and intake temperature adjusted. It was found that the cylinder- to-cylinder variation in HCCI combustion could be effectively reduced by the optimization in fuel injection proportion, and that the rapid transition process from SI to HCCI could be realized. The active fuel design technology could significantly increase the adaptability of HCCI combustion to increased EGR rate and reduced intake temperature. Active fuel design was shown to broaden the operational HCCI load to 9.3 bar indicated mean effective pressure （IMEP）. HCCI operation was used by up to 70% of the SI mode load while reducing fuel consumption and nitrogen oxides emissions. Therefore, the active fuel design technology could manage the right fuel for clean engine combustion, and provide a potential pathway for engine fuel diversification and future engine concept.
文摘In this paper the basic principle and the problems meriting attention in the design and application of active ear defenders are discussed quantitatively. A feasible structure and its experimental results are given. It is illustrated that the chief significance of ' active ' is to change the mechanical impedance of the ear defender accordingly, and because of this mechanism, the noise attenuation effectiveness in the low frequency range is improved.
基金supported by the National Natural Science Foundation of China(No.22204089,21801158 and 22306105)Natural Science Foundation of Shandong Province(No.ZR2023MB016 and ZR2022QB135).
文摘Metal-organic frameworks(MOFs)are porous organic-inorganic coordination materials with numerous active sites,enabling them to mimic the properties of natural enzymes and making them highly promising for sensing applications.This review provides a detailed overview of recent advancements in leveraging MOFs for the design of catalytic active sites in nanozymes.MOFs utilize metal ions and organic ligands as active centers for biomimetic catalysis,while their porous frameworks efficiently bind and stabilize multiple vip active units.Furthermore,MOFs can undergo chemical transformations to produce derivatives such as porous carbon materials and nanostructured metal compounds,enhancing their catalytic performance and broadening their applications as nanozymes.This review also explores the progress of MOF-based nanozymes across various catalytic modes in analytical sensing,highlighting their ability to significantly improve detection sensitivity,selectivity,and range.Additionally,the critical role of diverse active sites in sensing processes is emphasized,with attention to the design and synthesis strategies required to optimize the performance of MOF nanozymes.Finally,the review discusses future prospects for the development of MOF nanozymes and outlines key challenges that must be addressed to advance this field.
基金supported as part of the Center for Mesoscale Transport Properties,an Energy Frontier Research Center supported by the U.S.Department of Energy,Office of Science,Basic Energy Sciences,under award#DE-SC0012673support from the National Science Foundation funded Research Experience for Undergraduates Site:Nanotechnology for Health,Energy and the Environment at Stony Brook University.
文摘The importance of crystallite size control and direct synthesis of materials with desirable properties is broadly applicable for the rational design and development of new active materials for energy storage.Recently,the use of nanoparticles and crystallite size control has redefined electrode design strategies,due in part to the large surface area/volume ratios providing more pathways for ion movement within the bulk electrode.This review is structured primarily as a case study,where reports involving a specific densely structured iron oxide,magnetite,Fe_(3)O_(4),and its use as an electrode in LIBs are used as examples.Due to the high theoretical capacity(924 mA h g^(−1)),and opportunity for implementation of a low cost electrode material,magnetite was selected as the model material for this review.Notably,crystallite size,morphology,and electrode heterostructure can all play a critical role in battery relevant electrochemistry,particularly for crystallographically dense materials such as Fe_(3)O_(4).Several examples of Fe_(3)O_(4)based composites are described,incorporating different types of conductive materials such as carbons as part of the structure.Additionally,this review also provides a brief introduction to a newer iron oxide based material with a 2D layered structure,silver ferrite,where crystallite size control was synthetically achieved.By focusing on two specific iron oxide based nanoscale inorganic materials,this review highlights and distinguishes the contributions of electroactive material crystallite size,morphology and electrode heterostructure to electrochemical behavior,facilitating the future development of next generation of battery electrodes.
基金supported by the National Natural Science Foundation of China(NSFC No.51672265,51672266,51750110511,51672257,51932009,51929201,and 51672259)Science and Technology Cooperation Project between Chinese and Australian Governments(2017YFE0132300)+4 种基金the Key Research Program of Frontier Sciences,CAS(Grant No.YZDY-SSW-JSC018)the Scientific and Technological Department of Jilin Province(Grant No.20170414003GH)the Jiangmen Innovative Research Team Program(2017)the Major Program of Basic Research and Applied Research of Guangdong Province(2017KZDXM083)Open Funds of the State Key Laboratory of Rare Earth Resource Utilization(RERU2019003).
文摘Recently,controllable photoluminescence tuning by devising a solid solution framework,adjusting the valence mixing of Eu^(2+)/Eu^(3+)and designing efficient energy transfer between activator ions has been extensively investigated and reported due to its significant advantages in the improvement and regulation of the luminescence performances of white light-emitting diodes(W-LEDs).In this study,we designed a series of novel Eu^(2+)-doped(1-x)Ca_(3)(PO_(4))_(2)-xCa_(9)Y(PO_(4))_(7)(x=0-1.0)isostructural solid solution phosphors with aβ-Ca_(3)(PO_(4))_(2)-type structure,and powder samples were prepared via the traditional hightemperature solid-state reaction process.The crystal field variation around the Eu^(2+)ions causes superposition of linear luminescence and induces optical property tuning with a change in the solid solution ratio,x,values.Besides the high-energy emission peak at 418 nm in Ca_(3)(PO_(4))_(2):0.03Eu^(2+),another lowenergy emission peak at 486 nm was observed with the formation of the solid solution.Moreover,the corresponding high-energy emission peaks shifted from 418 to 430 nm,and the luminescence intensity of the low-energy emission at 486 nm increased with an increase in x,which was attributed to the combined effect of crystal field splitting of the local lattice and superposition of linear luminescence.In addition,tunable emission across the whole white light region could be realized by constructing a solid solution and adjusting the overall Eu concentration in(1-x)Ca_(3)(PO_(4))_(2)-xCa_(9)Y(PO_(4))_(7):Eu(x=0.5,0.7,0.9,and 1.0),and the corresponding luminescence mechanisms have been proposed and discussed in detail.In the pursuit of precise color tuning,we also tested the Eu^(2+)→Mn^(2+)energy transfer in different compositions(x=0.2,0.5,0.7,and 0.9)of the solid solution phosphors,and successive emission tuning from the blue and cyan range and then the red range was successfully achieved.Finally,the temperaturedependent photoluminescence and decay time were revealed systematically,and the corresponding mechanisms for the thermal quenching behavior have been discussed.This study provides a new perspective for color tuning originating from the simultaneous isostructural solid solution,valence mixing of Eu^(2+)/Eu^(3+)and efficient energy transfer.
基金financial support from the National Natural Science Foundation of China(NSFC grant no.21805082)the National Key Research and Development Program(2016YFB0302403).
文摘Spectral modification is crucial for luminescent materials.A variety of strategies have been proposed in the literature,including the selection of activator ions with characteristic electron configurations,the modification of the local crystal field,and the design of an emissive center pair and energy transfer.Eu^(2+)-activated haloapatites are considered as candidates for phosphor converted light emitting devices due to their excellent stabilities,easy preparation,and high efficiency.In this work,single-phased,single-doped(Ba,Sr)_(5)(PO_(4))_(3)Br:Eu^(2+)is selected and multiple approaches are applied,leading to multicolor tunabilities of the phosphors,including a crystal field strength controlled spectral shift,occupancy selectivity induced spectral saltation,defect-driven color tunability,and irradiation dependent dynamic chromaticity.In the high Eu^(2+)concentration doped Ba_(5−m)Sr_(m)(PO_(4))_(3)Br phosphor,the main emission band shifts from 448 to 452 nm with increasing Sr^(2+)/Ba^(2+)ratio,and a second emission band around the green region uplifts in the binary metal solid solution phosphors,leading to variable emission colors from blue to cyan under near UV excitation.Moreover,oxygen vacancy(VO)defects formed under synthetic reducing conditions endow the bromoapatites with bright self-activated luminescence.In the low Eu^(2+)concentration doped Ba_(2)Sr_(3)(PO_(4))_(3)Br,the combination of the broad yellow-green emission from VO and bluish emission from Eu^(2+)contributes to a full spectrum feature.The gradual increase of Eu^(2+)concentrations regulates the tunable emission from yellow-green,through white,to blue under short UV excitation.Furthermore,due to the different absorption preferences of these two centers,Ba_(2)Sr_(3)(PO_(4))_(3)Br:0.01Eu^(2+)shows white light emission under 254 nm irradiation while blue emission when exposed to 365 nm irradiation.The materials with multicolor luminescence show promising versatile applications in lighting,biological detection and anti-counterfeiting.The cooperative effects of multiple strategies provide a promising approach to regulate the optical properties of inorganic phosphors.
