The modern language teaching theory highly emphasizes the effect of"listening"on the learning and the use of language. The teaching of English listening is not only a teaching of language, but also a kind of...The modern language teaching theory highly emphasizes the effect of"listening"on the learning and the use of language. The teaching of English listening is not only a teaching of language, but also a kind of training of ability. In the four skills of listening, writing, reading and speaking, listening is considered as the basic, and the most important skill. It isn't only the main way of acquiring language information, but the base of improving other skills. Listening practice is especially important in classrooms where English is taught as a foreign language, that is, in situations where English is not the language of the country and where opportunities for hearing English outside the classroom are few. Students in such environments often learn to read and write English, and even to speak English, but they frequently have great difficulty comprehending English spoken to them.Plenty of Chinese students claim that the listening test is the most difficult part of English test. As a result, teachers should take particular pains to avoid such simplification and to provide opportunities for students to hear the kind of language that will prepare them for situations outside the classroom. Teachers should try to anticipate the kind of English the students will hear when the opportunity arises for them to be in an English-speaking country. In this article, I start with the factors which may exert an influence on listening comprehension, shows ways to improve listening comprehension and design some useful activities in the class. And I also focus on the activities of English listening teaching and insist that the activities should be both emphasized on the process of listening and the result of listening, due to different situations.展开更多
The rotating packed bed(RPB), mainly including the countercurrent-flow RPB(Counter-RPB) and the crosscurrentflow RPB(Cross-RPB) that are classified from the perspective of gas-liquid contact style, is a novel process ...The rotating packed bed(RPB), mainly including the countercurrent-flow RPB(Counter-RPB) and the crosscurrentflow RPB(Cross-RPB) that are classified from the perspective of gas-liquid contact style, is a novel process intensification device. A significant measurement standard for evaluating the performance of RPB is the mass transfer effect. In order to compare the mass transfer characteristics of Counter-RPB and Cross-RPB with the same size, the liquid volumetric mass transfer coefficient(k_La_e) and effective interfacial area(a_e) were measured under identical operating conditions. Meanwhile, the comparison of comprehensive mass transfer performance was conducted using the ratio of ΔP(pressure drop) to kLae as the standard. Experimental results indicated that kLae and ae increased with the increase in liquid spray density q, gas velocity u, and high gravity factor β. Furthermore, compared with the Cross-RPB, the Counter-RPB has higher liquid volumetric mass transfer coefficient and slightly larger effective interfacial area. The experimental results of comprehensive mass transfer performance showed that the Counter-RPB had higher ΔP/k_La_e than the Cross-RPB with changes in liquid spray density and high gravity factor, and there exists a turning point at 0.71 m/s accompanied by a variation with gas velocity. Moreover, the relative error of experimental value to calculated value, which was computed by the correlative expressions of kLae, was less than 5 %. In conclusion, the mass transfer characteristics of RPB are deeply impacted by the manner in which the flows are established and the Cross-RPB would have a great potential for industrial scale-up applications.展开更多
文摘The modern language teaching theory highly emphasizes the effect of"listening"on the learning and the use of language. The teaching of English listening is not only a teaching of language, but also a kind of training of ability. In the four skills of listening, writing, reading and speaking, listening is considered as the basic, and the most important skill. It isn't only the main way of acquiring language information, but the base of improving other skills. Listening practice is especially important in classrooms where English is taught as a foreign language, that is, in situations where English is not the language of the country and where opportunities for hearing English outside the classroom are few. Students in such environments often learn to read and write English, and even to speak English, but they frequently have great difficulty comprehending English spoken to them.Plenty of Chinese students claim that the listening test is the most difficult part of English test. As a result, teachers should take particular pains to avoid such simplification and to provide opportunities for students to hear the kind of language that will prepare them for situations outside the classroom. Teachers should try to anticipate the kind of English the students will hear when the opportunity arises for them to be in an English-speaking country. In this article, I start with the factors which may exert an influence on listening comprehension, shows ways to improve listening comprehension and design some useful activities in the class. And I also focus on the activities of English listening teaching and insist that the activities should be both emphasized on the process of listening and the result of listening, due to different situations.
基金supported by the National Key R&D Program of China:The ultra-low emission control technology for coal-fired industrial boilers(2016YFC0204103)the Provincial Key R&D Program of Shanxi:R&D of the coal-fired industrial boiler smoke ultra-low emission technology and equipment(201703D111018)
文摘The rotating packed bed(RPB), mainly including the countercurrent-flow RPB(Counter-RPB) and the crosscurrentflow RPB(Cross-RPB) that are classified from the perspective of gas-liquid contact style, is a novel process intensification device. A significant measurement standard for evaluating the performance of RPB is the mass transfer effect. In order to compare the mass transfer characteristics of Counter-RPB and Cross-RPB with the same size, the liquid volumetric mass transfer coefficient(k_La_e) and effective interfacial area(a_e) were measured under identical operating conditions. Meanwhile, the comparison of comprehensive mass transfer performance was conducted using the ratio of ΔP(pressure drop) to kLae as the standard. Experimental results indicated that kLae and ae increased with the increase in liquid spray density q, gas velocity u, and high gravity factor β. Furthermore, compared with the Cross-RPB, the Counter-RPB has higher liquid volumetric mass transfer coefficient and slightly larger effective interfacial area. The experimental results of comprehensive mass transfer performance showed that the Counter-RPB had higher ΔP/k_La_e than the Cross-RPB with changes in liquid spray density and high gravity factor, and there exists a turning point at 0.71 m/s accompanied by a variation with gas velocity. Moreover, the relative error of experimental value to calculated value, which was computed by the correlative expressions of kLae, was less than 5 %. In conclusion, the mass transfer characteristics of RPB are deeply impacted by the manner in which the flows are established and the Cross-RPB would have a great potential for industrial scale-up applications.
