[Objective] The experiment aimed to explore the influence of enhanced ultraviolet radiation-B on maize in arid regions of middle-high elevation for correct assessing the influence of enhanced ultraviolet radiation-B o...[Objective] The experiment aimed to explore the influence of enhanced ultraviolet radiation-B on maize in arid regions of middle-high elevation for correct assessing the influence of enhanced ultraviolet radiation-B on maize and providing scientific reference to make proper countermeasures. [ Method] The location test in field and lift lamp of UV-B were used to observe the changes of maize height, leaf area and number of green leaves under influences of different UV-B radiation. [ Result] In arid regions of middle-high elevation, enhanced ultraviolet radiation-B could dwarf maize plant, decrease leaf area, decline number of green leaves and yield. The reason of decreasing leaf area was that enhanced ultraviolet radiation-B shortened leaf length and leaf width while the reason of declining yield was that yield components were all negatively influ- enced and with the increase of ultraviolet radiation-B, the yield declined dramatically. [ Concluslonl The result of this experiment would be good for maize production in arid regions of middle-high elevation.展开更多
During molten salt cleaning of remanufactured 27SiMn hydraulic support column,oxidation occurs on the surface of metal substrate.This results in a change of the surface roughness of metal substrate after cleaning,whic...During molten salt cleaning of remanufactured 27SiMn hydraulic support column,oxidation occurs on the surface of metal substrate.This results in a change of the surface roughness of metal substrate after cleaning,which affects subsequent remanufacturing process.To decrease the effect is very important.This paper analyzed the oxidation mechanism of molten salt cleaning,explored the oxidation reaction that occurred during cleaning,and determined the key process parameters of cleaning that affecting oxidation reaction.By using central composite experimental design method and taking surface roughness variation of 27SiMn steel samples before and after molten salt cleaning as response variable to optimize the key process parameters,the optimal parameters of molten salt for cleaning remanufactured 27SiMn hydraulic support column could be obtained.The results show that the oxidation reaction of cleaning paint dirt can protect metal substrate from oxidation to a certain extent,and cleaning temperature and placement depth of metal substrate have a direct impact on the degree of oxidation reaction.When the cleaning temperature is 300℃and the distance between paint dirt and free surface of molten salt is 0.5 times the height of the parts,the surface roughness variation is minimal.Therefore,the cleaning quality will be improved under such parameters.展开更多
Three drums with different helical angles （15°, 20°, and 25°） were developed to investigate improved loading performance of the shearer drum. Nine trials were performed at different drum rotation spee...Three drums with different helical angles （15°, 20°, and 25°） were developed to investigate improved loading performance of the shearer drum. Nine trials were performed at different drum rotation speeds （80, 100, and 120 r/min） and different haulage speeds （1.5, 2.0, and 2.5 m/min） in an orthogonal test design. Loaded coal quantity and cutting power of the drum were the responses measured under the dif- ferent conditions. The effect of the parameters was determined by means of the extreme difference method. The significance of the effects was determined by analysis of variance. The results indicate that the effect from changes in the helical vane on loading performance of the drum is the largest in magnitude. The haulage speed has the least affect on loading performance. The helical angle has the least affect on cutting power of the drum. Haulage speed has the largest affect on the cutting power of the drum. 2011 Published by Elsevier B.V. on behalf of China University of Mining ＆ Technology.展开更多
With the aim of investigating the longitudinal washback of the innovated College English Test （CET） on College English （CE） classroom teaching and learning and ascertaining what changes the test innovation has bro...With the aim of investigating the longitudinal washback of the innovated College English Test （CET） on College English （CE） classroom teaching and learning and ascertaining what changes the test innovation has brought to CE in China, this study compares CE classes of a university in 2003 with those in 2009 through classroom observations, supplemented with interviews and questionnaire survey. The results indicate that the CE teaching model remains nearly the same before and after the CET innovation, but obvious changes are observed in terms of semester teaching plans, teaching content and teaching methods. It seems that the CET innovation is one of the main factors contributing to these changes, which, however, may also be attributed to other factors such as The College English Requirement, curriculum design, the use of CET results, teachers＇ individual differences, and students＇ English proficiency.展开更多
Implementing clinical trials with large multicenter samples is an important way to scientifically evaluate and demonstrate the curative effect of moxibustion.At present,clinical trials on moxibustion with large multic...Implementing clinical trials with large multicenter samples is an important way to scientifically evaluate and demonstrate the curative effect of moxibustion.At present,clinical trials on moxibustion with large multicenter samples are prospering in China.It is necessary for research units to have good research professionals and technical platforms as well as a highly standardized and scientifically feasible methodology of research.Taking tasks in the ongoing national 973 project and in the sci-tech support program of the "11th 5-year plan",for example,this research captures the characteristics of moxibustion,carries out deep analysis and introduces specific methods and the important significance of clinical research tasks on moxibustion in designing multicenter plans,implementing experiments,supervising quality and strengthening compliance.展开更多
基金Supported by Natural Science Foundation of Ningxia Autonomous Re-gion(A1012)~~
文摘[Objective] The experiment aimed to explore the influence of enhanced ultraviolet radiation-B on maize in arid regions of middle-high elevation for correct assessing the influence of enhanced ultraviolet radiation-B on maize and providing scientific reference to make proper countermeasures. [ Method] The location test in field and lift lamp of UV-B were used to observe the changes of maize height, leaf area and number of green leaves under influences of different UV-B radiation. [ Result] In arid regions of middle-high elevation, enhanced ultraviolet radiation-B could dwarf maize plant, decrease leaf area, decline number of green leaves and yield. The reason of decreasing leaf area was that enhanced ultraviolet radiation-B shortened leaf length and leaf width while the reason of declining yield was that yield components were all negatively influ- enced and with the increase of ultraviolet radiation-B, the yield declined dramatically. [ Concluslonl The result of this experiment would be good for maize production in arid regions of middle-high elevation.
基金supported by the National Natural Science Foundation of China(No.51375278)。
文摘During molten salt cleaning of remanufactured 27SiMn hydraulic support column,oxidation occurs on the surface of metal substrate.This results in a change of the surface roughness of metal substrate after cleaning,which affects subsequent remanufacturing process.To decrease the effect is very important.This paper analyzed the oxidation mechanism of molten salt cleaning,explored the oxidation reaction that occurred during cleaning,and determined the key process parameters of cleaning that affecting oxidation reaction.By using central composite experimental design method and taking surface roughness variation of 27SiMn steel samples before and after molten salt cleaning as response variable to optimize the key process parameters,the optimal parameters of molten salt for cleaning remanufactured 27SiMn hydraulic support column could be obtained.The results show that the oxidation reaction of cleaning paint dirt can protect metal substrate from oxidation to a certain extent,and cleaning temperature and placement depth of metal substrate have a direct impact on the degree of oxidation reaction.When the cleaning temperature is 300℃and the distance between paint dirt and free surface of molten salt is 0.5 times the height of the parts,the surface roughness variation is minimal.Therefore,the cleaning quality will be improved under such parameters.
基金support for this work was provided by the National Natural Science Foundation of China (No. 51005232)the China Postdoctoral Science Foundation (No. 20100481176)
文摘Three drums with different helical angles （15°, 20°, and 25°） were developed to investigate improved loading performance of the shearer drum. Nine trials were performed at different drum rotation speeds （80, 100, and 120 r/min） and different haulage speeds （1.5, 2.0, and 2.5 m/min） in an orthogonal test design. Loaded coal quantity and cutting power of the drum were the responses measured under the dif- ferent conditions. The effect of the parameters was determined by means of the extreme difference method. The significance of the effects was determined by analysis of variance. The results indicate that the effect from changes in the helical vane on loading performance of the drum is the largest in magnitude. The haulage speed has the least affect on loading performance. The helical angle has the least affect on cutting power of the drum. Haulage speed has the largest affect on the cutting power of the drum. 2011 Published by Elsevier B.V. on behalf of China University of Mining ＆ Technology.
基金part of the achievements funded by the Fundamental Research Funds for the Central Universities in China(No.0205005201030)the National Scholarship Council of China(No.2010850066) granted to the second author to support a one-year visiting professorship and period of collaboration with University of Cambridge ESOL Examinations from October 2011 to September 2012
文摘With the aim of investigating the longitudinal washback of the innovated College English Test （CET） on College English （CE） classroom teaching and learning and ascertaining what changes the test innovation has brought to CE in China, this study compares CE classes of a university in 2003 with those in 2009 through classroom observations, supplemented with interviews and questionnaire survey. The results indicate that the CE teaching model remains nearly the same before and after the CET innovation, but obvious changes are observed in terms of semester teaching plans, teaching content and teaching methods. It seems that the CET innovation is one of the main factors contributing to these changes, which, however, may also be attributed to other factors such as The College English Requirement, curriculum design, the use of CET results, teachers＇ individual differences, and students＇ English proficiency.
基金Supported by the National "11th 5-year Plan" (2006BAI12B04-2)National Plan on Developing Key Basic Researches(973 Plan)(2009CB522902)+1 种基金State Natural Science Fund(30760320)a project of Key Sci-tech Support Plan in Jiangxi
文摘Implementing clinical trials with large multicenter samples is an important way to scientifically evaluate and demonstrate the curative effect of moxibustion.At present,clinical trials on moxibustion with large multicenter samples are prospering in China.It is necessary for research units to have good research professionals and technical platforms as well as a highly standardized and scientifically feasible methodology of research.Taking tasks in the ongoing national 973 project and in the sci-tech support program of the "11th 5-year plan",for example,this research captures the characteristics of moxibustion,carries out deep analysis and introduces specific methods and the important significance of clinical research tasks on moxibustion in designing multicenter plans,implementing experiments,supervising quality and strengthening compliance.
