Using semi-tensor product of matrices, the controllability and stabilizability of finite automata are investigated. By expressing the states, inputs, and outputs in vector forms, the transition and output functions ar...Using semi-tensor product of matrices, the controllability and stabilizability of finite automata are investigated. By expressing the states, inputs, and outputs in vector forms, the transition and output functions are represented in matrix forms.Based on this algebraic description, a necessary and sufficient condition is proposed for checking whether a state is controllable to another one. By this condition, an algorithm is established to find all the control sequences of an arbitrary length. Moreover, the stabilizability of finite automata is considered, and a necessary and sufficient condition is presented to examine whether some states can be stabilized. Finally, the study of illustrative examples verifies the correctness of the presented results/algorithms.展开更多
The author uses system analysis to provide system thinkings of the deepening reform of the management of defence science, technology and industry (DSTI) and investigate the system definition of DSTI, the system reform...The author uses system analysis to provide system thinkings of the deepening reform of the management of defence science, technology and industry (DSTI) and investigate the system definition of DSTI, the system reform target, system operational mechanism, institutional structure, coordination and control functions and the orientation of conversion in China.展开更多
The serious competition environment of global marke t requests the enterprise to change traditional product development strategy and a dopt new theory in order to meet diverse customer needs while maintaining near m a...The serious competition environment of global marke t requests the enterprise to change traditional product development strategy and a dopt new theory in order to meet diverse customer needs while maintaining near m ass production efficiency, which is the main philosophy of mass customization. P roduct family design is research focus at present and also is the core technolog y of DFMC (design for mass customization). Firstly, this paper explores the fund amental issues of product family, such as concepts of modularity, commonality/di versity, product platform and product family architecture etc. We compare the te rminology between product family and object-oriented approach in the next step. Thirdly, this paper puts forwards one product family design methodology based o n product platform and under different phase of product life cycle constrains, f or example, functional, assembly and service etc. At the end section of this pap er, we applied, the object-oriented approach in above mentioned product family design methodology to realize the design process. In one word, this paper propos ed one product family design methodology based on object oriented approach and p roduct life cycle consideration, especially the conjointness of characteristic o f OOA and concepts of product family. The main property of OOA are encapsulation , inherence and polymorphism. Encapsulation can represent the module or building blocks of product family. Inherence can be extended to describe the modularity and commonality, and also be used to construct variant space. Alternative specif ic of product family architecture can be embodied with polymorphism. And fin aly, we give the future work contents. In order to derive the product platform a nd achieve modularity and commonality/diversity, interface management between bu ilding block is necessary. The question is how the OOA can be applied in interfa ce management to get our aim OOA is the basis of many information management sy stem, then the question is how to build one system to manage the information of product family and support mass customization The third question is how to deve lop one computer aided tool to facilitate the application of OOA for product fam ily design, even be used to category of design for mass customization.展开更多
The spatial and temporal distributions of new production vary largely in different sea areas. To understand the level of new production in the sea area studied better, an estimate of new production must be obtained in...The spatial and temporal distributions of new production vary largely in different sea areas. To understand the level of new production in the sea area studied better, an estimate of new production must be obtained in large spatial and temporal scales. The ~234Th/ ~238U disequilibrium is an effective method for the study of new production. Two sampling strategies, vertically integrated sampling ap proach based on trapezoidal integration principle and discrete layer sampling approach, were compared in the studies of the xiamen Bay and the northern South China Sea. The scavenging fluxes and removal fluxes of ~234Th and the residence times for dissolved and particulate ~234Th were calculated. The coinci dent results from two Sampling approach suggest that vertically integrated sampling approach is not only effective and reliable, but also significantly reduces the number and volume of samples. It allows us to study new production by ba ^(234)Th - ^(238)U disequilibria in large spatial scale.展开更多
As pig production is a main contributor of greenhouse gas(GHG) emissions from livestock sector,the carbon emissions of pig production are attracting increasing attention,especially in the developing countries. Based o...As pig production is a main contributor of greenhouse gas(GHG) emissions from livestock sector,the carbon emissions of pig production are attracting increasing attention,especially in the developing countries. Based on the panel data of 30 provinces in China from 2001 to 2012,this paper measures the provincial carbon emission performance(CEP) of pig production and we use a Malmquist DEA approach to analyze the decomposition which includes desirable and undesirable output. Furthermore,the regional disparity in carbon emission performance of pig production is also analyzed and finally the convergence is tested. The main results are as follows:(i) there are provincial differences in carbon emission performance changing of pig production in China,and the carbon emission performance of pig production in 30 provinces has a downward trend during this period;(ii) among China’s three major economic regions,in terms of carbon emission performance of pig production,they are ranked in descending order as follows: Western China,Central China and Eastern China;(iii) convergence testing shows that there is a convergence trend for carbon emission performance both nationally and for the three regions.展开更多
This study applies a stochastic frontier production approach to decompose the sources of total productivity (TFP) growth into technical progress and changes in technical efficiency of 8057 firms in Vietnamese manufact...This study applies a stochastic frontier production approach to decompose the sources of total productivity (TFP) growth into technical progress and changes in technical efficiency of 8057 firms in Vietnamese manufacturing industries during 2003-2007. Using both total manufacturing industry and sub-manufacturing industrial regressions, the analysis focuses on the trend of technological progress (TP) and technical efficiency change (TEC), and the role of productivity change in economic growth. According to the estimated results, the annual technical progress for the manufacturing industry and sub-manufacturing industries are calculated directly from the estimated parameters of the translog stochastic frontier production function by taking a partial derivative of output with respect to time t. The average technical changes in manufacturing industry and sub-manufacturing industries are positive, with an average technical change about 5.2%, 5.8%, 5.4%, 11.8%, 4.6%, 4.1%, 7.3%, 4.8%, 4.8% and 4.8% for total sample, food products & beverages, textile & wearing apparel, footwear, paper & products, industrial chemicals, rubber & plastic products, non- metallic mineral, basic & fabricated metal and other sub-industries, respectively. Total TFP in the manufacturing sector has grown at the annual rate of 0.052, although the rate of growth decreased continuously during the sample period. For the sub-industry estimates during the sample period, TFP grew fastest in the footwear sub-industry, with annual average growth rate of 11.8%, followed by the rubber & plastic products with a rate of 7.3%, and the food products & beverages with a rate of 5.8% per annum.展开更多
English writing, as a basic language skill for second language learners, is being paid close attention to. How to achieve better results in English teaching and how to develop students＇ writing competence remain an a...English writing, as a basic language skill for second language learners, is being paid close attention to. How to achieve better results in English teaching and how to develop students＇ writing competence remain an arduous task for English teachers. This paper introduces three writing approaches that are currently popular in English writing teaching field, i.e., the product approach, the process approach and the genre approach, and offers some discussion on the three approaches each approach shows its strengths and weaknesses, but meanwhile they are largely complementary. Then this paper attempts to propose an integrated approach which is not only a synthesis of the above three approaches, but also draws on some experiences of traditional Chinese language teaching methods.展开更多
To the issue on the superiority and inferiority of the ＂product approach＂ and the ＂process approach＂ writing teaching, an empirical study research of I00 non-English major students has been accomplished to testify...To the issue on the superiority and inferiority of the ＂product approach＂ and the ＂process approach＂ writing teaching, an empirical study research of I00 non-English major students has been accomplished to testify the relationship between these different approaches and the different writing levels. The results are the ＂product approach＂ is more helpful to the learners with lower writing level; whereas, the ＂process approach＂ is more effective to ones with higher level. Furthermore, the teaching approach itself cannot affirm the superiority and inferiority, and it would not be at work unless is applied for corresponding learners.展开更多
The production of J/ψ mesons in p+p and p+Pb collisions is studied in the framework of color-glass condensate together with a simple color evaporation model.Considering the nuclear effects with the Glauber–Gribov ap...The production of J/ψ mesons in p+p and p+Pb collisions is studied in the framework of color-glass condensate together with a simple color evaporation model.Considering the nuclear effects with the Glauber–Gribov approach,we calculate the cross section and the nuclear modification factor of forward J/ψ production in p+Pb collisions at s^(1/2) 5:02 TeV.Then,the backward J/ψ production in p+Pb collisions at s^(1/2) 8:16 Te V is also analyzed.In our calculation,the phenomenology KLRAd S/CFT model and the rc BK approach,which are valid at a small x,are used to calculate the three-point function.It is shown that the theoretical results fit well with the experimental data from ALICE and LHCb.展开更多
Currently,English writing is still an important and challenging course for most students in English.In China,the effect of Product-oriented approaches is dominated.Such practice seems to have ignored cognitive factors...Currently,English writing is still an important and challenging course for most students in English.In China,the effect of Product-oriented approaches is dominated.Such practice seems to have ignored cognitive factors of writing process.So it is necessary to choose some new ways to perfect our English writing teaching.In this paper the application of a new approach——process-oriented approach will be discussed.By using this approach,the students can develop some behaviors such as composing,brainstorming,drafting,and revising.展开更多
n engineering framework system to support integrated product and process development is developed. It consists of the product data management level, development tool level, and development process management level. Th...n engineering framework system to support integrated product and process development is developed. It consists of the product data management level, development tool level, and development process management level. The product data management level supplies an integrated information environment to enable a multifunctional team to work efficiently by using a product data management system. The development tool level is made up of many standalone software tools for product development. These software tools are encapsulated in the product data management system. In the development process management level, the object classes involved in product development and the static relationships among these object classes are constructed using objectoriented approach. An IDEF3 process flow diagram for a product development process is described. The process flow diagram is directly transformed into its corresponding objectoriented Petri net(OPN) model. The conflicting events specified by the OPN model are analyzed. The control strategy for resolving each conflict event is provided. Through the mapping between IDEF3 process flow diagrams and life cycles in the product data management system,a development process manager for constructing and controling flexible product development processes and automatically capturing the rationales for design decisions is built.展开更多
Take Suburban Hanjiang District of Yangzhou as an example, based on the comprehensive analysis of total grain yield, yield per unit, planting areas and patterns over the recent years, present problems and constraints ...Take Suburban Hanjiang District of Yangzhou as an example, based on the comprehensive analysis of total grain yield, yield per unit, planting areas and patterns over the recent years, present problems and constraints in this district under the background of continuous yield increase are pointed out and main approaches of high and stable grain yield in suburbs under new situations are studied, which provides references for grain production in the same type of regions.展开更多
Understanding the net primary productivity(NPP) of grassland is crucial to evaluate the terrestrial carbon cycle. In this study, we investigated the spatial distribution and the area of global grassland across the glo...Understanding the net primary productivity(NPP) of grassland is crucial to evaluate the terrestrial carbon cycle. In this study, we investigated the spatial distribution and the area of global grassland across the globe. Then, we used the Carnegie-Ames-Stanford Approach(CASA) model to estimate global grassland NPP and explore the spatio-temporal variations of grassland NPP in response to climate change from 1982 to 2008. Results showed that the largest area of grassland distribution during the study period was in Asia(1737.23 × 104 km^2), while the grassland area in Europe was relatively small(202.83 × 10~4 km^2). Temporally, the total NPP increased with fluctuations from 1982 to 2008, with an annual increase rate of 0.03 Pg C/yr. The total NPP experienced a significant increasing trend from 1982 to 1995, while a decreasing trend was observed from 1996 to 2008. Spatially, the grassland NPP in South America and Africa were higher than the other regions, largely as a result of these regions are under warm and wet climatic conditions. The highest mean NPP was recorded for savannas(560.10 g C/(m^2·yr)), whereas the lowest was observed in open shrublands with an average NPP of 162.53 g C/(m^2·yr). The relationship between grassland NPP and annual mean temperature and annual precipitation(AMT, AP, respectively) varies with changes in AP, which indicates that, grassland NPP is more sensitive to precipitation than temperature.展开更多
Approaches toward the sustainable development need integrated considerations of technical, economical, environmental/ecological and social issues. Current approaches from different disciplines can be grouped into at l...Approaches toward the sustainable development need integrated considerations of technical, economical, environmental/ecological and social issues. Current approaches from different disciplines can be grouped into at least three levels: micro-scale, meso-scale and macro-scale. At the micro-scale, green chemistry carries out chemical activities such as chemical design and synthesis so that environmentally benign chemicals can be synthesized without using and generating hazardous substances. Green engineering, at the meso-scale, develops green industrial processes or clean technologies via pollution prevention and cleaner production, which will cause minimal damages or dangers to the environment and ecosystems when the product is manufactured and used. Industrial ecology at the industrial complex or community level seeks to optimize energy and materials use and minimize waste generation in industrial systems or communities by promoting planned materials and energy exchanges. Incorporation of ecological principles with the life cycle thinking in the chemical pathway synthesis, product design, process development, and industrial system and community planning appears to be the most promising engineering approach in achieving sustainable industrial development.展开更多
Speech production involves four main processes including conceptualization,formulation,articulation and self-monitoring.During these processes,learners need to use sociocultural,pragmatic and discourse knowledge in co...Speech production involves four main processes including conceptualization,formulation,articulation and self-monitoring.During these processes,learners need to use sociocultural,pragmatic and discourse knowledge in conceptualization,vocabulary and grammar in formulation,and phonological knowledge in articulation.By utilizing the knowledge mentioned above,learners are expected to possess such speaking skills as routine skills and improvisation skills.Current speaking teaching methods are broadly divided into"skill-getting"direct approach and"skill-using"indirect approach.As they are mutually complementary,a balance of activities types should be provided.On the basis of these theories,a modification of a listening and speaking lesson in New Cutting Edge Pre-intermediate is designed to get students notice,retrieve and use some useful expressions for giving direction.展开更多
Recently,there has been growing attention on English teaching and learning in China.Writing plays a large part in theimprovement of English learning.Raimes(1983:6)suggests that a variety of approaches to the teaching ...Recently,there has been growing attention on English teaching and learning in China.Writing plays a large part in theimprovement of English learning.Raimes(1983:6)suggests that a variety of approaches to the teaching of writing have been devel-oped in accordance with how teachers think writing is learned.Although,Badger and White(2000)claims that product,process,and genre approaches to writing haves their strengths and weaknesses and the three approaches are complementary.Consideringthe specific situation of English writing teaching and learning in China,the employment of process approach into senior Englishcourse book design will be appropriate for development of high school students’writing.High school students in China rely a lot onteachers’guidance and treat writing as a task in isolation.Process approach,which concerns more of how ideas are developed dur-ing process of writing,is beneficial for students in terms of fostering independent thinking ability and making full use of writing as avaluable learning tool.展开更多
基金supported by the National Natural Science Foundation of China(61174094)the Tianjin Natural Science Foundation of China(13JCYBJC1740014JCYBJC18700)
文摘Using semi-tensor product of matrices, the controllability and stabilizability of finite automata are investigated. By expressing the states, inputs, and outputs in vector forms, the transition and output functions are represented in matrix forms.Based on this algebraic description, a necessary and sufficient condition is proposed for checking whether a state is controllable to another one. By this condition, an algorithm is established to find all the control sequences of an arbitrary length. Moreover, the stabilizability of finite automata is considered, and a necessary and sufficient condition is presented to examine whether some states can be stabilized. Finally, the study of illustrative examples verifies the correctness of the presented results/algorithms.
文摘The author uses system analysis to provide system thinkings of the deepening reform of the management of defence science, technology and industry (DSTI) and investigate the system definition of DSTI, the system reform target, system operational mechanism, institutional structure, coordination and control functions and the orientation of conversion in China.
文摘The serious competition environment of global marke t requests the enterprise to change traditional product development strategy and a dopt new theory in order to meet diverse customer needs while maintaining near m ass production efficiency, which is the main philosophy of mass customization. P roduct family design is research focus at present and also is the core technolog y of DFMC (design for mass customization). Firstly, this paper explores the fund amental issues of product family, such as concepts of modularity, commonality/di versity, product platform and product family architecture etc. We compare the te rminology between product family and object-oriented approach in the next step. Thirdly, this paper puts forwards one product family design methodology based o n product platform and under different phase of product life cycle constrains, f or example, functional, assembly and service etc. At the end section of this pap er, we applied, the object-oriented approach in above mentioned product family design methodology to realize the design process. In one word, this paper propos ed one product family design methodology based on object oriented approach and p roduct life cycle consideration, especially the conjointness of characteristic o f OOA and concepts of product family. The main property of OOA are encapsulation , inherence and polymorphism. Encapsulation can represent the module or building blocks of product family. Inherence can be extended to describe the modularity and commonality, and also be used to construct variant space. Alternative specif ic of product family architecture can be embodied with polymorphism. And fin aly, we give the future work contents. In order to derive the product platform a nd achieve modularity and commonality/diversity, interface management between bu ilding block is necessary. The question is how the OOA can be applied in interfa ce management to get our aim OOA is the basis of many information management sy stem, then the question is how to build one system to manage the information of product family and support mass customization The third question is how to deve lop one computer aided tool to facilitate the application of OOA for product fam ily design, even be used to category of design for mass customization.
基金National Natural Science Foundation of China! 49676296National Scientific and Technical Project! 97-926-04-02.
文摘The spatial and temporal distributions of new production vary largely in different sea areas. To understand the level of new production in the sea area studied better, an estimate of new production must be obtained in large spatial and temporal scales. The ~234Th/ ~238U disequilibrium is an effective method for the study of new production. Two sampling strategies, vertically integrated sampling ap proach based on trapezoidal integration principle and discrete layer sampling approach, were compared in the studies of the xiamen Bay and the northern South China Sea. The scavenging fluxes and removal fluxes of ~234Th and the residence times for dissolved and particulate ~234Th were calculated. The coinci dent results from two Sampling approach suggest that vertically integrated sampling approach is not only effective and reliable, but also significantly reduces the number and volume of samples. It allows us to study new production by ba ^(234)Th - ^(238)U disequilibria in large spatial scale.
基金Supported by National Natural Science Foundation of China(41171436)National Social Science Foundation of China(14AZD002)
文摘As pig production is a main contributor of greenhouse gas(GHG) emissions from livestock sector,the carbon emissions of pig production are attracting increasing attention,especially in the developing countries. Based on the panel data of 30 provinces in China from 2001 to 2012,this paper measures the provincial carbon emission performance(CEP) of pig production and we use a Malmquist DEA approach to analyze the decomposition which includes desirable and undesirable output. Furthermore,the regional disparity in carbon emission performance of pig production is also analyzed and finally the convergence is tested. The main results are as follows:(i) there are provincial differences in carbon emission performance changing of pig production in China,and the carbon emission performance of pig production in 30 provinces has a downward trend during this period;(ii) among China’s three major economic regions,in terms of carbon emission performance of pig production,they are ranked in descending order as follows: Western China,Central China and Eastern China;(iii) convergence testing shows that there is a convergence trend for carbon emission performance both nationally and for the three regions.
文摘This study applies a stochastic frontier production approach to decompose the sources of total productivity (TFP) growth into technical progress and changes in technical efficiency of 8057 firms in Vietnamese manufacturing industries during 2003-2007. Using both total manufacturing industry and sub-manufacturing industrial regressions, the analysis focuses on the trend of technological progress (TP) and technical efficiency change (TEC), and the role of productivity change in economic growth. According to the estimated results, the annual technical progress for the manufacturing industry and sub-manufacturing industries are calculated directly from the estimated parameters of the translog stochastic frontier production function by taking a partial derivative of output with respect to time t. The average technical changes in manufacturing industry and sub-manufacturing industries are positive, with an average technical change about 5.2%, 5.8%, 5.4%, 11.8%, 4.6%, 4.1%, 7.3%, 4.8%, 4.8% and 4.8% for total sample, food products & beverages, textile & wearing apparel, footwear, paper & products, industrial chemicals, rubber & plastic products, non- metallic mineral, basic & fabricated metal and other sub-industries, respectively. Total TFP in the manufacturing sector has grown at the annual rate of 0.052, although the rate of growth decreased continuously during the sample period. For the sub-industry estimates during the sample period, TFP grew fastest in the footwear sub-industry, with annual average growth rate of 11.8%, followed by the rubber & plastic products with a rate of 7.3%, and the food products & beverages with a rate of 5.8% per annum.
文摘English writing, as a basic language skill for second language learners, is being paid close attention to. How to achieve better results in English teaching and how to develop students＇ writing competence remain an arduous task for English teachers. This paper introduces three writing approaches that are currently popular in English writing teaching field, i.e., the product approach, the process approach and the genre approach, and offers some discussion on the three approaches each approach shows its strengths and weaknesses, but meanwhile they are largely complementary. Then this paper attempts to propose an integrated approach which is not only a synthesis of the above three approaches, but also draws on some experiences of traditional Chinese language teaching methods.
文摘To the issue on the superiority and inferiority of the ＂product approach＂ and the ＂process approach＂ writing teaching, an empirical study research of I00 non-English major students has been accomplished to testify the relationship between these different approaches and the different writing levels. The results are the ＂product approach＂ is more helpful to the learners with lower writing level; whereas, the ＂process approach＂ is more effective to ones with higher level. Furthermore, the teaching approach itself cannot affirm the superiority and inferiority, and it would not be at work unless is applied for corresponding learners.
基金supported by the Natural Science Foundation of Hebei Province(A2012210043)
文摘The production of J/ψ mesons in p+p and p+Pb collisions is studied in the framework of color-glass condensate together with a simple color evaporation model.Considering the nuclear effects with the Glauber–Gribov approach,we calculate the cross section and the nuclear modification factor of forward J/ψ production in p+Pb collisions at s^(1/2) 5:02 TeV.Then,the backward J/ψ production in p+Pb collisions at s^(1/2) 8:16 Te V is also analyzed.In our calculation,the phenomenology KLRAd S/CFT model and the rc BK approach,which are valid at a small x,are used to calculate the three-point function.It is shown that the theoretical results fit well with the experimental data from ALICE and LHCb.
文摘Currently,English writing is still an important and challenging course for most students in English.In China,the effect of Product-oriented approaches is dominated.Such practice seems to have ignored cognitive factors of writing process.So it is necessary to choose some new ways to perfect our English writing teaching.In this paper the application of a new approach——process-oriented approach will be discussed.By using this approach,the students can develop some behaviors such as composing,brainstorming,drafting,and revising.
文摘n engineering framework system to support integrated product and process development is developed. It consists of the product data management level, development tool level, and development process management level. The product data management level supplies an integrated information environment to enable a multifunctional team to work efficiently by using a product data management system. The development tool level is made up of many standalone software tools for product development. These software tools are encapsulated in the product data management system. In the development process management level, the object classes involved in product development and the static relationships among these object classes are constructed using objectoriented approach. An IDEF3 process flow diagram for a product development process is described. The process flow diagram is directly transformed into its corresponding objectoriented Petri net(OPN) model. The conflicting events specified by the OPN model are analyzed. The control strategy for resolving each conflict event is provided. Through the mapping between IDEF3 process flow diagrams and life cycles in the product data management system,a development process manager for constructing and controling flexible product development processes and automatically capturing the rationales for design decisions is built.
文摘Take Suburban Hanjiang District of Yangzhou as an example, based on the comprehensive analysis of total grain yield, yield per unit, planting areas and patterns over the recent years, present problems and constraints in this district under the background of continuous yield increase are pointed out and main approaches of high and stable grain yield in suburbs under new situations are studied, which provides references for grain production in the same type of regions.
基金Under the auspices of Asia Pacific Network for Global Change Research(APN)Global Change Fund Project(No.ARCP2015-03CMY-Li)+2 种基金National Natural Science Foundation of China(No.41271361,41501575)National Key Research and Development Project(No.2018YFD0800201)Key Project of Chinese National Programs for Fundamental Research and Development(No.2010CB950702)
文摘Understanding the net primary productivity(NPP) of grassland is crucial to evaluate the terrestrial carbon cycle. In this study, we investigated the spatial distribution and the area of global grassland across the globe. Then, we used the Carnegie-Ames-Stanford Approach(CASA) model to estimate global grassland NPP and explore the spatio-temporal variations of grassland NPP in response to climate change from 1982 to 2008. Results showed that the largest area of grassland distribution during the study period was in Asia(1737.23 × 104 km^2), while the grassland area in Europe was relatively small(202.83 × 10~4 km^2). Temporally, the total NPP increased with fluctuations from 1982 to 2008, with an annual increase rate of 0.03 Pg C/yr. The total NPP experienced a significant increasing trend from 1982 to 1995, while a decreasing trend was observed from 1996 to 2008. Spatially, the grassland NPP in South America and Africa were higher than the other regions, largely as a result of these regions are under warm and wet climatic conditions. The highest mean NPP was recorded for savannas(560.10 g C/(m^2·yr)), whereas the lowest was observed in open shrublands with an average NPP of 162.53 g C/(m^2·yr). The relationship between grassland NPP and annual mean temperature and annual precipitation(AMT, AP, respectively) varies with changes in AP, which indicates that, grassland NPP is more sensitive to precipitation than temperature.
文摘Approaches toward the sustainable development need integrated considerations of technical, economical, environmental/ecological and social issues. Current approaches from different disciplines can be grouped into at least three levels: micro-scale, meso-scale and macro-scale. At the micro-scale, green chemistry carries out chemical activities such as chemical design and synthesis so that environmentally benign chemicals can be synthesized without using and generating hazardous substances. Green engineering, at the meso-scale, develops green industrial processes or clean technologies via pollution prevention and cleaner production, which will cause minimal damages or dangers to the environment and ecosystems when the product is manufactured and used. Industrial ecology at the industrial complex or community level seeks to optimize energy and materials use and minimize waste generation in industrial systems or communities by promoting planned materials and energy exchanges. Incorporation of ecological principles with the life cycle thinking in the chemical pathway synthesis, product design, process development, and industrial system and community planning appears to be the most promising engineering approach in achieving sustainable industrial development.
文摘Speech production involves four main processes including conceptualization,formulation,articulation and self-monitoring.During these processes,learners need to use sociocultural,pragmatic and discourse knowledge in conceptualization,vocabulary and grammar in formulation,and phonological knowledge in articulation.By utilizing the knowledge mentioned above,learners are expected to possess such speaking skills as routine skills and improvisation skills.Current speaking teaching methods are broadly divided into"skill-getting"direct approach and"skill-using"indirect approach.As they are mutually complementary,a balance of activities types should be provided.On the basis of these theories,a modification of a listening and speaking lesson in New Cutting Edge Pre-intermediate is designed to get students notice,retrieve and use some useful expressions for giving direction.
文摘Recently,there has been growing attention on English teaching and learning in China.Writing plays a large part in theimprovement of English learning.Raimes(1983:6)suggests that a variety of approaches to the teaching of writing have been devel-oped in accordance with how teachers think writing is learned.Although,Badger and White(2000)claims that product,process,and genre approaches to writing haves their strengths and weaknesses and the three approaches are complementary.Consideringthe specific situation of English writing teaching and learning in China,the employment of process approach into senior Englishcourse book design will be appropriate for development of high school students’writing.High school students in China rely a lot onteachers’guidance and treat writing as a task in isolation.Process approach,which concerns more of how ideas are developed dur-ing process of writing,is beneficial for students in terms of fostering independent thinking ability and making full use of writing as avaluable learning tool.
