Based on the surveys and the statistic data during 1980-2003, the variation character of grain yield per unit area in Northeast China and its main factors have been discussed by the methods of statistics and grey corr...Based on the surveys and the statistic data during 1980-2003, the variation character of grain yield per unit area in Northeast China and its main factors have been discussed by the methods of statistics and grey correlation analysis. The results show that: 1) the grain yield per unit area has been taking on an increasing trend in the recent 20 years. It increased from 2519.80kg/ha in 1980 to 4216.11kg/ha in 2003, with an increasing rate of 67.32%; 2) the variation of grain yield per unit area is considerably prominent and its range is also very great, with the maximal increase rate of 42.59% and maximal decrease rate of 21.13%, respectively, which are far above the whole Chinese average level; 3) the variation of main crops' yield per unit area is remarkable, which takes on the character that the yield of corn is much higher than that of soybean and rice; and 4) the grey correlation analysis shows that the most important factors impacting the variation of grain yield per unit area are the total power of agricultural machinery, the consumption of chemical fertilizer and effective irrigated area. However, the influence of natural disaster and income level should not be ignored. Effective ways to improve grain yield per unit area are to construct farmland improvement groundwork, reclaim the middle- and low-yield farmland, etc.展开更多
As one of the important policies of promoting the formation of main functional areas, the industrial policy directly determines the sustainable growth of space control ability of main functional areas. A restricted de...As one of the important policies of promoting the formation of main functional areas, the industrial policy directly determines the sustainable growth of space control ability of main functional areas. A restricted development zone is a type of main functional area which provides agricultural products and ecological products, assures the supply of national agricultural products and the stability of ecosystems, as well as safeguards the ecological functions and agricultural functions of wider regions by restricting its own development. Therefore scientific, complete and operable industrial policy support is needed. Restricted development zones are distributed widely in western China. With the restriction of their main functions, differential industrial policies should be implemented in the development of the restricted development zones: Dealing well with the relationship between industrial development and ecological protection, developing special industries which are friendly to resources and environment and appropriate for local conditions, guiding and encouraging industries to learn from regions with favorable development conditions, orderly withdrawing industries and enterprises adverse to main functions, facilitating industrial structure upgrading, optimizing industrial organization, improving industrial technological level and rationalizing industrial layout.展开更多
Flavotoxin A was isolated from Pseudomonas cocovenenans subsp. farinofermentans culture in semisolid potato-dextrose-agar medium, which was isolated from fermented corn meal that had caused food poisoning outbreaks in...Flavotoxin A was isolated from Pseudomonas cocovenenans subsp. farinofermentans culture in semisolid potato-dextrose-agar medium, which was isolated from fermented corn meal that had caused food poisoning outbreaks in China. The isolation, purification, and chemical structure of this toxin were studied. The NMR spectra, the uv spectra, and molar extinction coefficients, and the mass spectra of Flavotoxin A are in good agreement with those reported for bongkrekic acid. Therefore, Flavotoxin A and bongkrekic acid are the same organic chemical compound; the molecular formula is C_(28)H_(38)O_7. The oral LD_(50) of the purified Flavotoxin A in mice was 3.16mg/kg (1.53-6.15mg/kg). The existence of bongkrekic acid in toxic fermented corn samples collected during food poisoning outbreaks was also confirmed. It is concluded that bongkrekic acid has played an important role in the outbreaks of fermented corn poisoning. 1989 Academic Press, Inc.展开更多
基金Under the auspices of the National Natural Science Foundation of China (No. 40601027)
文摘Based on the surveys and the statistic data during 1980-2003, the variation character of grain yield per unit area in Northeast China and its main factors have been discussed by the methods of statistics and grey correlation analysis. The results show that: 1) the grain yield per unit area has been taking on an increasing trend in the recent 20 years. It increased from 2519.80kg/ha in 1980 to 4216.11kg/ha in 2003, with an increasing rate of 67.32%; 2) the variation of grain yield per unit area is considerably prominent and its range is also very great, with the maximal increase rate of 42.59% and maximal decrease rate of 21.13%, respectively, which are far above the whole Chinese average level; 3) the variation of main crops' yield per unit area is remarkable, which takes on the character that the yield of corn is much higher than that of soybean and rice; and 4) the grey correlation analysis shows that the most important factors impacting the variation of grain yield per unit area are the total power of agricultural machinery, the consumption of chemical fertilizer and effective irrigated area. However, the influence of natural disaster and income level should not be ignored. Effective ways to improve grain yield per unit area are to construct farmland improvement groundwork, reclaim the middle- and low-yield farmland, etc.
基金the paper is the phased achievement of Projects of the National Social Science Foundation of China——“Study on the Supporting Policies in Limited Development Zones”(11BJL058) directed by the author
文摘As one of the important policies of promoting the formation of main functional areas, the industrial policy directly determines the sustainable growth of space control ability of main functional areas. A restricted development zone is a type of main functional area which provides agricultural products and ecological products, assures the supply of national agricultural products and the stability of ecosystems, as well as safeguards the ecological functions and agricultural functions of wider regions by restricting its own development. Therefore scientific, complete and operable industrial policy support is needed. Restricted development zones are distributed widely in western China. With the restriction of their main functions, differential industrial policies should be implemented in the development of the restricted development zones: Dealing well with the relationship between industrial development and ecological protection, developing special industries which are friendly to resources and environment and appropriate for local conditions, guiding and encouraging industries to learn from regions with favorable development conditions, orderly withdrawing industries and enterprises adverse to main functions, facilitating industrial structure upgrading, optimizing industrial organization, improving industrial technological level and rationalizing industrial layout.
文摘Flavotoxin A was isolated from Pseudomonas cocovenenans subsp. farinofermentans culture in semisolid potato-dextrose-agar medium, which was isolated from fermented corn meal that had caused food poisoning outbreaks in China. The isolation, purification, and chemical structure of this toxin were studied. The NMR spectra, the uv spectra, and molar extinction coefficients, and the mass spectra of Flavotoxin A are in good agreement with those reported for bongkrekic acid. Therefore, Flavotoxin A and bongkrekic acid are the same organic chemical compound; the molecular formula is C_(28)H_(38)O_7. The oral LD_(50) of the purified Flavotoxin A in mice was 3.16mg/kg (1.53-6.15mg/kg). The existence of bongkrekic acid in toxic fermented corn samples collected during food poisoning outbreaks was also confirmed. It is concluded that bongkrekic acid has played an important role in the outbreaks of fermented corn poisoning. 1989 Academic Press, Inc.
