Freshwater shortage is the main problem in Heilonggang lower-lying plain, while a considerable amount of underground saline water is available. We wanted to find an effective way to use the brackish water in winter wh...Freshwater shortage is the main problem in Heilonggang lower-lying plain, while a considerable amount of underground saline water is available. We wanted to find an effective way to use the brackish water in winter wheat production. Surface mulch has significant effect in reducing evaporation and decreasing soil salinity level. This research was aimed at comparing the effect of different mulch materials on winter wheat production. The experiment was conducted during 2002-2003 and 2003-2004. Four treatments were setup： （1） no mulch, （2） mulch with plastic film, （3） mulch with corn straw, （4） mulch with concrete slab between the rows. The result indicated that concrete mulch and straw mulch was effective in conserving soil water compared to plastic film mulch which increased soil temperature. Concrete mulch decreases surface soil salinity better in comparison to other mulches used. Straw mulch conserved more soil water but decreased wheat grain yield probably due to low temperature. Concrete mulch had similar effect with plastic film mulch on promoting winter wheat development and growth.展开更多
Theory of film condensation heat transfer(FCHT) for vapor condensed on horizontal tube bundle(HTB) is vital to many industry processes.Meanwhile,the inundation effect is the key to model the film condensation heat tra...Theory of film condensation heat transfer(FCHT) for vapor condensed on horizontal tube bundle(HTB) is vital to many industry processes.Meanwhile,the inundation effect is the key to model the film condensation heat transfer coefficient(CHTC) on HTB.This paper proposed a new experimental method,homologous method,to obtain the inundation effect precisely.Based on the requirements of the new test method,a new test facility was designed and established.Then,the superiority of homologous method for inundation effect was investigated based on experiment result and theoretic analysis.The results showed that the homogenous method can effectively control the experimental error of inundation effect,which is less than 50% of the error of CHTC,and less than 30% of the error of the inundation effect gained by routine method.The new test facility built for the homogenous method is excellent in obtaining the accurate inundation effect of film condensation on HTB.All the result is a foundation of the theoretical development of the FCHT on HTB.展开更多
基金Project supported by the Hi-Tech Research and Development Program (863) of China (No. 2002AA2Z404), and the Key Innovation Project (No. KZCX3-SW-446) from Chinese Academy of Sciences,China
文摘Freshwater shortage is the main problem in Heilonggang lower-lying plain, while a considerable amount of underground saline water is available. We wanted to find an effective way to use the brackish water in winter wheat production. Surface mulch has significant effect in reducing evaporation and decreasing soil salinity level. This research was aimed at comparing the effect of different mulch materials on winter wheat production. The experiment was conducted during 2002-2003 and 2003-2004. Four treatments were setup： （1） no mulch, （2） mulch with plastic film, （3） mulch with corn straw, （4） mulch with concrete slab between the rows. The result indicated that concrete mulch and straw mulch was effective in conserving soil water compared to plastic film mulch which increased soil temperature. Concrete mulch decreases surface soil salinity better in comparison to other mulches used. Straw mulch conserved more soil water but decreased wheat grain yield probably due to low temperature. Concrete mulch had similar effect with plastic film mulch on promoting winter wheat development and growth.
基金supported by the National Natural Science Foundation of China (Grant No. 51078053)the Fundamental Research Funds for the Central Universities of China (Grant No. DUT11ZD105)
文摘Theory of film condensation heat transfer(FCHT) for vapor condensed on horizontal tube bundle(HTB) is vital to many industry processes.Meanwhile,the inundation effect is the key to model the film condensation heat transfer coefficient(CHTC) on HTB.This paper proposed a new experimental method,homologous method,to obtain the inundation effect precisely.Based on the requirements of the new test method,a new test facility was designed and established.Then,the superiority of homologous method for inundation effect was investigated based on experiment result and theoretic analysis.The results showed that the homogenous method can effectively control the experimental error of inundation effect,which is less than 50% of the error of CHTC,and less than 30% of the error of the inundation effect gained by routine method.The new test facility built for the homogenous method is excellent in obtaining the accurate inundation effect of film condensation on HTB.All the result is a foundation of the theoretical development of the FCHT on HTB.
