Environmentalists'approach to sustainable development is essentially different fromeconomists'in that environmental sustainability is set as a condition in biophysical limits. Furthermorethere exist alternativ...Environmentalists'approach to sustainable development is essentially different fromeconomists'in that environmental sustainability is set as a condition in biophysical limits. Furthermorethere exist alternative strategies for achieving environmental sustainability. This paper intends to assessand compare these alternatives in the context of environmental resource stock and economic outcomes , sothat the circumstances in which a particular strategy is preferred.would be suggested.展开更多
Feedbacks given by teachers is possibly a common instruction in second language writing classes, to help students makeprogress in writing. At one time, feedback was almost entirely at a superficial level--identifying ...Feedbacks given by teachers is possibly a common instruction in second language writing classes, to help students makeprogress in writing. At one time, feedback was almost entirely at a superficial level--identifying the grammatical errors and givingthe correct form. However, recently, this type of feedback has begun to be challenged by some researchers(eg.,Krashen, 1984, Trus-cott, 1996),who argue that teachers should be more concerned with the content of essay instead of grammatical errors. This essaywill discuss some research surrounding feedback to students' writing and will try to find the answer to the question whether the er-ror corrective feedback should be abandoned. In order to find the answer, the essay will elaborate on two parts: some literary reviewabout the issue and some suggested solutions to the issue.展开更多
The natural phenomenon associated with the chemical dissolution of dissolvable minerals of rocks can be employed to develop innovative technology in mining and oil extracting engineering. This paper presents a new alt...The natural phenomenon associated with the chemical dissolution of dissolvable minerals of rocks can be employed to develop innovative technology in mining and oil extracting engineering. This paper presents a new alternative approach for theoretically dealing with chemical dissolution front （CDF） propagation in fluid-saturated carbonate rocks. Note that the CDF is represented by the porosity front in this study. In this new approach, the porosity, pore-fluid velocity and acid concentration are directly used as independent variables. To illustrate how to use the present new approach, an aeidization dissolution system （ADS） consisting of carbonate rocks, which belongs to one of the many general chemical dissolution systems （CDSs）, is taken as an application example. When the acid dissolution capacity （ADC） number （that is defined as the ratio of the volume of the carbonate rock dissolved by an acid to that of the acid） approaches zero, the present new approach can be used to obtain analytical solutions for the stable ADS. However, if the ADC number is a nonzero finite number, then numerical solutions can be only obtained for the ADS, especially when the ADS is in an unstable state. The related theoretical results have demonstrated that： （1） When the ADS is in a stable state and in the case of the ADC number approaching zero, the present new approach is mathematically equivalent to the previous approach, in which the porosity, pore-fluid pressure and acid concentration are used as independent variables. However, when the ADS is in an unstable state, the use of the present new approach leads to a free parameter that needs to be determined by some other ways. （2） The existence of a non-step-type dissolution front within a transient region should at least satisfy that none of the ADC number, injected acid velocity and reciprocal of the dissolution reaction rate is equal to zero in the stable ADS.展开更多
The paper regards young adult literature (YAL) as a dissolved-point between localization and globalization of English teaching, and discusses (1) whether the western YAL teaching theories, methods and teaching materia...The paper regards young adult literature (YAL) as a dissolved-point between localization and globalization of English teaching, and discusses (1) whether the western YAL teaching theories, methods and teaching materials accord with Chinese actual situation well or not, (2) if YAL reading is an effective way for creating life-long readers, and (3) why and how to teach YAL. Based on YAL learning and teaching practice, the author uses Soter's YAL theories and alternative approaches, try to clarify three relationships: YA-YAL; adult literature-YAL-children's literature; classics-YAL balance. And put forward three ways for books selection and three reading patterns to YAL teaching.展开更多
文摘Environmentalists'approach to sustainable development is essentially different fromeconomists'in that environmental sustainability is set as a condition in biophysical limits. Furthermorethere exist alternative strategies for achieving environmental sustainability. This paper intends to assessand compare these alternatives in the context of environmental resource stock and economic outcomes , sothat the circumstances in which a particular strategy is preferred.would be suggested.
文摘Feedbacks given by teachers is possibly a common instruction in second language writing classes, to help students makeprogress in writing. At one time, feedback was almost entirely at a superficial level--identifying the grammatical errors and givingthe correct form. However, recently, this type of feedback has begun to be challenged by some researchers(eg.,Krashen, 1984, Trus-cott, 1996),who argue that teachers should be more concerned with the content of essay instead of grammatical errors. This essaywill discuss some research surrounding feedback to students' writing and will try to find the answer to the question whether the er-ror corrective feedback should be abandoned. In order to find the answer, the essay will elaborate on two parts: some literary reviewabout the issue and some suggested solutions to the issue.
基金supported by the National Natural Science Foundation of China(Grant No.11272359)
文摘The natural phenomenon associated with the chemical dissolution of dissolvable minerals of rocks can be employed to develop innovative technology in mining and oil extracting engineering. This paper presents a new alternative approach for theoretically dealing with chemical dissolution front （CDF） propagation in fluid-saturated carbonate rocks. Note that the CDF is represented by the porosity front in this study. In this new approach, the porosity, pore-fluid velocity and acid concentration are directly used as independent variables. To illustrate how to use the present new approach, an aeidization dissolution system （ADS） consisting of carbonate rocks, which belongs to one of the many general chemical dissolution systems （CDSs）, is taken as an application example. When the acid dissolution capacity （ADC） number （that is defined as the ratio of the volume of the carbonate rock dissolved by an acid to that of the acid） approaches zero, the present new approach can be used to obtain analytical solutions for the stable ADS. However, if the ADC number is a nonzero finite number, then numerical solutions can be only obtained for the ADS, especially when the ADS is in an unstable state. The related theoretical results have demonstrated that： （1） When the ADS is in a stable state and in the case of the ADC number approaching zero, the present new approach is mathematically equivalent to the previous approach, in which the porosity, pore-fluid pressure and acid concentration are used as independent variables. However, when the ADS is in an unstable state, the use of the present new approach leads to a free parameter that needs to be determined by some other ways. （2） The existence of a non-step-type dissolution front within a transient region should at least satisfy that none of the ADC number, injected acid velocity and reciprocal of the dissolution reaction rate is equal to zero in the stable ADS.
文摘The paper regards young adult literature (YAL) as a dissolved-point between localization and globalization of English teaching, and discusses (1) whether the western YAL teaching theories, methods and teaching materials accord with Chinese actual situation well or not, (2) if YAL reading is an effective way for creating life-long readers, and (3) why and how to teach YAL. Based on YAL learning and teaching practice, the author uses Soter's YAL theories and alternative approaches, try to clarify three relationships: YA-YAL; adult literature-YAL-children's literature; classics-YAL balance. And put forward three ways for books selection and three reading patterns to YAL teaching.
