An experiment was conducted during Kharif seasons of 2009 and 2010 on sandy loam soil of West Bengal, India to evaluate the productivity and economic viability of maize ＋ legume intercropping systems in additive as w...An experiment was conducted during Kharif seasons of 2009 and 2010 on sandy loam soil of West Bengal, India to evaluate the productivity and economic viability of maize ＋ legume intercropping systems in additive as well as in replacement series with different row proportions. Maize （Zea rnays L.） cv. ＂Vijay＂ （composite）, green gram （Vigna radiata L.） cv. ＂Samrat＂, black gram （Vigna mungo L.） cv. ＂Sarada＂, soybean （Glycine max L. Merril） cv. ＂PK 327＂ and peanut （Arachis hypogaea L.） cv. ＂JL 24＂, were tested in monoculture as well as in intercropping situations with 1：1 （additive series） and 1：2 ratios （replacement series）. The result indicated that intercropped legumes improved the yield components of maize and offered some bonus yield. The highest maize grain yield （2,916.28 kg/ha） and maize equivalent yield （4,831.45 kg/ha） were recorded with maize ＋ green gram （1：1） and maize ＋ peanut （1：I）, respectively. The values of all the competition functions were always greater than unity and maize ＋ black gram （1：2） recorded the highest values of land equivalent ratio （1.433）, area time equivalent ratio （1.374） and land equivalent coefficient （0.421）. Maximum monetary advantage （Rs. 10,579.13） was found with maize ＋ green gam （l：1）. Maize ＋ peanut （1：2） combination recorded the highest relative net return （2.01）, net return （Rs. 28,523.08）, benefit-cost ratio （2.76） ad per day return （Rs. 259.30）.展开更多
To improve the equivalent inertia of DC microgrids(DCMGs),a unified control is proposed for the first time for a bi-directional DC-DC converter based super-capacitor(SC)system,whereby power smoothing and SC terminal v...To improve the equivalent inertia of DC microgrids(DCMGs),a unified control is proposed for the first time for a bi-directional DC-DC converter based super-capacitor(SC)system,whereby power smoothing and SC terminal voltage regulation can be achieved in a DCMG simultaneously.The proposed control displays good plug-and-play features using only local measurements.For quantitative analysis and effective design of the critical parameter of unified control,two indices,equivalent power supporting time and inertia contributed by the unified controlled SC system,are introduced firstly.Then,with a simple but effective reduced-order model of a DCMG,analytical solutions are obtained for the two indices.In addition,a systematic design method is presented for the proposed unified control.Finally,to verify the proposed unified control,a switching model is developed for a typical DCMG in PSCAD/EMTDC,and theoretical analyses are conducted for different operating conditions.展开更多
文摘An experiment was conducted during Kharif seasons of 2009 and 2010 on sandy loam soil of West Bengal, India to evaluate the productivity and economic viability of maize ＋ legume intercropping systems in additive as well as in replacement series with different row proportions. Maize （Zea rnays L.） cv. ＂Vijay＂ （composite）, green gram （Vigna radiata L.） cv. ＂Samrat＂, black gram （Vigna mungo L.） cv. ＂Sarada＂, soybean （Glycine max L. Merril） cv. ＂PK 327＂ and peanut （Arachis hypogaea L.） cv. ＂JL 24＂, were tested in monoculture as well as in intercropping situations with 1：1 （additive series） and 1：2 ratios （replacement series）. The result indicated that intercropped legumes improved the yield components of maize and offered some bonus yield. The highest maize grain yield （2,916.28 kg/ha） and maize equivalent yield （4,831.45 kg/ha） were recorded with maize ＋ green gram （1：1） and maize ＋ peanut （1：I）, respectively. The values of all the competition functions were always greater than unity and maize ＋ black gram （1：2） recorded the highest values of land equivalent ratio （1.433）, area time equivalent ratio （1.374） and land equivalent coefficient （0.421）. Maximum monetary advantage （Rs. 10,579.13） was found with maize ＋ green gam （l：1）. Maize ＋ peanut （1：2） combination recorded the highest relative net return （2.01）, net return （Rs. 28,523.08）, benefit-cost ratio （2.76） ad per day return （Rs. 259.30）.
基金supported in part by the National Nature Science Foundation(No.51977142)National Key R&D Program of China(No.2020YFB1506803)Tianjin Natural Science Foundation(No.20JCQNJC00350)。
文摘To improve the equivalent inertia of DC microgrids(DCMGs),a unified control is proposed for the first time for a bi-directional DC-DC converter based super-capacitor(SC)system,whereby power smoothing and SC terminal voltage regulation can be achieved in a DCMG simultaneously.The proposed control displays good plug-and-play features using only local measurements.For quantitative analysis and effective design of the critical parameter of unified control,two indices,equivalent power supporting time and inertia contributed by the unified controlled SC system,are introduced firstly.Then,with a simple but effective reduced-order model of a DCMG,analytical solutions are obtained for the two indices.In addition,a systematic design method is presented for the proposed unified control.Finally,to verify the proposed unified control,a switching model is developed for a typical DCMG in PSCAD/EMTDC,and theoretical analyses are conducted for different operating conditions.
