The Panel Data of corn production in 11 provinces are analyzed,such as Jilin,Heilongjiang,Liaoning,Inner Mongolia,Hebei,Shandong,Henan,Anhui,Jiangsu,Hubei and Sichuan.Based on the CRS,VRS and Malmquist exponential mod...The Panel Data of corn production in 11 provinces are analyzed,such as Jilin,Heilongjiang,Liaoning,Inner Mongolia,Hebei,Shandong,Henan,Anhui,Jiangsu,Hubei and Sichuan.Based on the CRS,VRS and Malmquist exponential models of DEA,technical efficiency of corn production is measured in main producing region by DEA-Tobit.And its influencing factors are analyzed.Result shows that corn production in main producing areas is mainly scale inefficiency and is at the stage of decreasing returns to scale.Pure technical efficiency of corn production is effective in most main producing regions.Total Factor Productivity of corn production is improved in main producing regions,because the speed of technical progress is greater than the speed of efficiency reduction.In the years 1998-2008,corn production in main producing regions is rational in structure and is not affected by the natural disasters.展开更多
To reveal the characteristic chemicals of walnuts from different origins, we analyzed fatty acid composition,tocopherols, phytosterols and total phenolic content (TPC) of walnuts from three main producing regions inCh...To reveal the characteristic chemicals of walnuts from different origins, we analyzed fatty acid composition,tocopherols, phytosterols and total phenolic content (TPC) of walnuts from three main producing regions inChina. The results showed that walnuts were rich in polyunsaturated fatty acids, and the ratio of ω-6 to ω-3 fattyacids was close to the recommendation of Chinese Nutrition Society. Moreover, walnuts contain high contents oftocopherols (331.20–414.71 mg/kg), phytosterols (97.17–110.35 mg/100 g) and phenols (38.51–48.08 mg GAE/kg). Significant chemical differences exist among walnuts from three production regions. The highest content ofpolyunsaturated fatty acids was found in walnuts from the northern China, the highest content of tocopherols inwalnuts from southwest China, and the highest contents of phytosterol and TPC in walnuts from northwest China.However, there was no significant difference in the tocopherol, phytosterol and TPC content of walnuts betweenthe Northern China and Northwest China. The above results provide important references for manufacturers andconsumers to select suitable walnut scientifically and reasonably.展开更多
In order to reveal the attribute clearly and to understand the situation of the regional cropland-grain-population relationship,this paper presents the "cropland contribution index" model,and divides the cro...In order to reveal the attribute clearly and to understand the situation of the regional cropland-grain-population relationship,this paper presents the "cropland contribution index" model,and divides the cropland contribution land index into four levels,that is below subsistence,subsistence,well-off,and richness.Then,it analyzes the whole China,13 main producing regions,11 grain balancing regions,and 7 main sales regions.Results show that the overall cropland contribution index presented a rising trend in 1949 to 2010,it once reached well-off level in 1996 to 1999,and it reached the well-off level again in 2010,but there is still a long way to reach the level of richness.The cropland contribution index is relatively high in main producing regions.In 2010,all main producing regions reached the well-off level,and some provinces even reached the richness level.However,the cropland contribution index of main sales regions is lower and takes on a downtrend,especially in Guangdong,Zhejiang,and Fujian provinces.The cropland contribution index in grain balancing regions is not high,and most provinces are still at subsistence level.Researches have indicated that the cropland contribution index can simply and rapidly reflect the relation between regional cropland,grain and population.展开更多
基金Supported by the National Philosophy and Social Science Foundation(08AJY034)the Eleventh-Five Year Planning Program of the Education Department of Jilin Province([2008]No.202)
文摘The Panel Data of corn production in 11 provinces are analyzed,such as Jilin,Heilongjiang,Liaoning,Inner Mongolia,Hebei,Shandong,Henan,Anhui,Jiangsu,Hubei and Sichuan.Based on the CRS,VRS and Malmquist exponential models of DEA,technical efficiency of corn production is measured in main producing region by DEA-Tobit.And its influencing factors are analyzed.Result shows that corn production in main producing areas is mainly scale inefficiency and is at the stage of decreasing returns to scale.Pure technical efficiency of corn production is effective in most main producing regions.Total Factor Productivity of corn production is improved in main producing regions,because the speed of technical progress is greater than the speed of efficiency reduction.In the years 1998-2008,corn production in main producing regions is rational in structure and is not affected by the natural disasters.
基金supported by the National Key Research and Development Project of China(2021YFD1600101)the earmarked fund for China Agriculture research system(CARS-12 and CARS-13)the Agricultural Science and Technology Innovation Program of Chinese Academy of Agricultural Sciences(CAAS-ASTIP-2021-OCRI).
文摘To reveal the characteristic chemicals of walnuts from different origins, we analyzed fatty acid composition,tocopherols, phytosterols and total phenolic content (TPC) of walnuts from three main producing regions inChina. The results showed that walnuts were rich in polyunsaturated fatty acids, and the ratio of ω-6 to ω-3 fattyacids was close to the recommendation of Chinese Nutrition Society. Moreover, walnuts contain high contents oftocopherols (331.20–414.71 mg/kg), phytosterols (97.17–110.35 mg/100 g) and phenols (38.51–48.08 mg GAE/kg). Significant chemical differences exist among walnuts from three production regions. The highest content ofpolyunsaturated fatty acids was found in walnuts from the northern China, the highest content of tocopherols inwalnuts from southwest China, and the highest contents of phytosterol and TPC in walnuts from northwest China.However, there was no significant difference in the tocopherol, phytosterol and TPC content of walnuts betweenthe Northern China and Northwest China. The above results provide important references for manufacturers andconsumers to select suitable walnut scientifically and reasonably.
文摘In order to reveal the attribute clearly and to understand the situation of the regional cropland-grain-population relationship,this paper presents the "cropland contribution index" model,and divides the cropland contribution land index into four levels,that is below subsistence,subsistence,well-off,and richness.Then,it analyzes the whole China,13 main producing regions,11 grain balancing regions,and 7 main sales regions.Results show that the overall cropland contribution index presented a rising trend in 1949 to 2010,it once reached well-off level in 1996 to 1999,and it reached the well-off level again in 2010,but there is still a long way to reach the level of richness.The cropland contribution index is relatively high in main producing regions.In 2010,all main producing regions reached the well-off level,and some provinces even reached the richness level.However,the cropland contribution index of main sales regions is lower and takes on a downtrend,especially in Guangdong,Zhejiang,and Fujian provinces.The cropland contribution index in grain balancing regions is not high,and most provinces are still at subsistence level.Researches have indicated that the cropland contribution index can simply and rapidly reflect the relation between regional cropland,grain and population.
