The Follow up Move Research has been deepening after it was first defined in 1975 by Sinclair and Coulthard, but it has not been paid attention in China, let alone study its effect in the classroom. In this essay base...The Follow up Move Research has been deepening after it was first defined in 1975 by Sinclair and Coulthard, but it has not been paid attention in China, let alone study its effect in the classroom. In this essay based on the author＇s literature reading, the Follow up move functions and their language features are classified; its pragmatic motivations are researched and some factors which affect its relevance of occurrence are studied. Then with this guide of the frame four teachers classroom follow up moves are studied. Finally, the other scholars＇ findings in this field are commented and then the author＇s own insights are put forward.展开更多
In this study, it shows how the main indicators of torsional vibrations of the crankshaft change when its materials change. In the study, the crankshaft of diesel engine with four cylinders in line was taken, in which...In this study, it shows how the main indicators of torsional vibrations of the crankshaft change when its materials change. In the study, the crankshaft of diesel engine with four cylinders in line was taken, in which the material is changing from steel to cast iron, due to the technological possibilities of production. For study of torsional vibration of crankshaft system, the construction of equivalent reduced scheme is carried. Reduced inertia moments of discs are determined for each crank of crankshaft, by receiving the impact of piston group and rod mass. Reduced rigidities of crank are determined by experimental method. The results show that the rigidity of crank for the same crankshaft varies up to 6%, while the change between crankshafts goes up 10%. At the end, frequency and vibration forms are calculated using Tole-Holxer method. From calculations, it results that the frequencies are 19% smaller, while the vibration forms varies slightly. In this case, the change of the materials leads to the first frequency in the area of engine rotations and it can worsen the level of torsional vibration, therefore, it should check the resonance areas and vibration amplitude.展开更多
To obtain the near optimal path for the mobile robots in the present of the obstacles, where the robots are subject to both the nonholonomic constraints and the bound to the curvature of the path, a simple planning i...To obtain the near optimal path for the mobile robots in the present of the obstacles, where the robots are subject to both the nonholonomic constraints and the bound to the curvature of the path, a simple planning is applied by the heuristic searching method in which Reeds and Shepp’s shortest paths are chosen as heuristic functions. It has performed well in simulation of mobile robots moving in a cluttered environment.展开更多
Reusable launch vehicle is an important way to realize fast,cheap and reliable space transportation.A combined cycle engine system provides a more efficient and flexible form of power.The investigation on the research...Reusable launch vehicle is an important way to realize fast,cheap and reliable space transportation.A combined cycle engine system provides a more efficient and flexible form of power.The investigation on the research status of the combined cycle engine technology,including basic principle,research programs and classification of structure is firstly discussed in this paper.Then the bilevel hierarchical and integrated parameters/trajectory overall optimization technologies are applied to improve the efficiency and effectiveness of overall vehicle design.Simulations are implemented to compare and analyze the effectiveness and adaptability of the two algorithms,in order to provide the technical reserves and beneficial references for further research on combined cycle engine reusable launch vehicles.展开更多
This study aims to explore the effectiveness of the emerging m-learning in the form of smart phones in English grammar teaching. The research mainly traces revision process of 100 sophomore students using traditional ...This study aims to explore the effectiveness of the emerging m-learning in the form of smart phones in English grammar teaching. The research mainly traces revision process of 100 sophomore students using traditional paperwork practice and smart-phone-based revision methods during half semester of grammar learning. During the research, students＇ learning performances, as well as their self-report reflections, are recorded, compared, and analyzed. Statistics from the research show that students in general prefer the m-learning revision methods than the traditional paper ones. Besides, the modem methods do play an essential role in motivating students＇ learning initiatives, and thus resulting in better learning outcomes. However, on the other hand, some of the students surveyed also demonstrate their negative impression on the m-learning methods, in that they believe this modem technology can inevitably distract them from learning and there are also some technical problems to be worked out.展开更多
The changes of numeraire can be used as a very powerful tool in pricing contingent claims in the context of a complete market.By using the method of numeraire changes to evaluate convertible bonds when the value of fi...The changes of numeraire can be used as a very powerful tool in pricing contingent claims in the context of a complete market.By using the method of numeraire changes to evaluate convertible bonds when the value of firm,and those of zero-coupon bonds follow general adapted stochastic processes in this paper,using Ito theorem and Gisanov theorem.A closed-form solution is derived under the stochastic volatility by using fast Fourier transforms.展开更多
文摘The Follow up Move Research has been deepening after it was first defined in 1975 by Sinclair and Coulthard, but it has not been paid attention in China, let alone study its effect in the classroom. In this essay based on the author＇s literature reading, the Follow up move functions and their language features are classified; its pragmatic motivations are researched and some factors which affect its relevance of occurrence are studied. Then with this guide of the frame four teachers classroom follow up moves are studied. Finally, the other scholars＇ findings in this field are commented and then the author＇s own insights are put forward.
文摘In this study, it shows how the main indicators of torsional vibrations of the crankshaft change when its materials change. In the study, the crankshaft of diesel engine with four cylinders in line was taken, in which the material is changing from steel to cast iron, due to the technological possibilities of production. For study of torsional vibration of crankshaft system, the construction of equivalent reduced scheme is carried. Reduced inertia moments of discs are determined for each crank of crankshaft, by receiving the impact of piston group and rod mass. Reduced rigidities of crank are determined by experimental method. The results show that the rigidity of crank for the same crankshaft varies up to 6%, while the change between crankshafts goes up 10%. At the end, frequency and vibration forms are calculated using Tole-Holxer method. From calculations, it results that the frequencies are 19% smaller, while the vibration forms varies slightly. In this case, the change of the materials leads to the first frequency in the area of engine rotations and it can worsen the level of torsional vibration, therefore, it should check the resonance areas and vibration amplitude.
文摘To obtain the near optimal path for the mobile robots in the present of the obstacles, where the robots are subject to both the nonholonomic constraints and the bound to the curvature of the path, a simple planning is applied by the heuristic searching method in which Reeds and Shepp’s shortest paths are chosen as heuristic functions. It has performed well in simulation of mobile robots moving in a cluttered environment.
文摘Reusable launch vehicle is an important way to realize fast,cheap and reliable space transportation.A combined cycle engine system provides a more efficient and flexible form of power.The investigation on the research status of the combined cycle engine technology,including basic principle,research programs and classification of structure is firstly discussed in this paper.Then the bilevel hierarchical and integrated parameters/trajectory overall optimization technologies are applied to improve the efficiency and effectiveness of overall vehicle design.Simulations are implemented to compare and analyze the effectiveness and adaptability of the two algorithms,in order to provide the technical reserves and beneficial references for further research on combined cycle engine reusable launch vehicles.
文摘This study aims to explore the effectiveness of the emerging m-learning in the form of smart phones in English grammar teaching. The research mainly traces revision process of 100 sophomore students using traditional paperwork practice and smart-phone-based revision methods during half semester of grammar learning. During the research, students＇ learning performances, as well as their self-report reflections, are recorded, compared, and analyzed. Statistics from the research show that students in general prefer the m-learning revision methods than the traditional paper ones. Besides, the modem methods do play an essential role in motivating students＇ learning initiatives, and thus resulting in better learning outcomes. However, on the other hand, some of the students surveyed also demonstrate their negative impression on the m-learning methods, in that they believe this modem technology can inevitably distract them from learning and there are also some technical problems to be worked out.
基金supported by the National key scientific instrument and Equipment Development Program of China under Grant No.2012YQ220119Anhui Provincial Natural Science Foundation under Grant No.1308085 MF93+1 种基金the Fundamental Research Foundation for the Central Universities under Grant No.2013HGXJ0223National Natural Science Foundations of China under Grant No.11201108
文摘The changes of numeraire can be used as a very powerful tool in pricing contingent claims in the context of a complete market.By using the method of numeraire changes to evaluate convertible bonds when the value of firm,and those of zero-coupon bonds follow general adapted stochastic processes in this paper,using Ito theorem and Gisanov theorem.A closed-form solution is derived under the stochastic volatility by using fast Fourier transforms.
