Most of the important agronomic traits in crop plants, such as yield, quality and stress response, are quantitative and jointly controlled by many genomic loci or major genes. Improving these complex traits depends on...Most of the important agronomic traits in crop plants, such as yield, quality and stress response, are quantitative and jointly controlled by many genomic loci or major genes. Improving these complex traits depends on the combination of beneficial alleles at the quantitative trait loci （QTLs）. However, the conventional cross breeding method is extremely time-consuming and laborious for pyramiding multiple QTLs. In certain cases, this approach might be technically difficult because of close linkage between genes separately responsible for desirable and undesirable traits.展开更多
We give definitions on increasing, constant and decreasing returns to scale under the generalized data envelopment analysis (GDEA) model. The GDEA model prossesses cone structures for describing evaluators’ preferenc...We give definitions on increasing, constant and decreasing returns to scale under the generalized data envelopment analysis (GDEA) model. The GDEA model prossesses cone structures for describing evaluators’ preferences toward different decision making units (DMU) and toward different input / output categories. The GDEA model contains many important DEA models as its subclasses. Based upon the definition, we discuss and rigorously prove the necessary and sufficient conditions for a DMU to have increasing, constant and decreasing returns to scale under a GDEA model, and discuss and clarify the differences and relationships of these conditions under different subclasses of the GDEA model. Furthermore, we describe a method based on a two-stage linear program to test returns to scale properties.展开更多
With the increasing integration of wind farms and electric vehicles(EVs)in power systems,voltage stability is becoming more and more serious.Based on vehicle-to-grid(V2G),an efficient power plant model of EVs(E-EPP)wa...With the increasing integration of wind farms and electric vehicles(EVs)in power systems,voltage stability is becoming more and more serious.Based on vehicle-to-grid(V2G),an efficient power plant model of EVs(E-EPP)was developed to estimate EV charging load with available corresponding response capacity under different charging strategies.A preventive control strategy based on E-EPP was proposed to maintain the static voltage stability margin(VSM)of power system above a predefined security level.Two control modes were used including the disconnection of EV charging load(‘V1G’mode)and the discharge of stored battery energy back to power grid(‘V2G’mode).A modified IEEE 14-bus system with high penetration of wind power and EVs was used to verify the effectiveness of preventive control strategy.Simulation results showed that the proposed strategy can not only improve the static voltage stability of power system with considerable wind generation,but also guarantee the travelling comfort for EV owners.展开更多
Establishment of a highly efficient regeneration system for the mature embryo of wheat will provide a convenient tool for wheat tissue culture and transformation, thereby facilitating the transformation of foreign gen...Establishment of a highly efficient regeneration system for the mature embryo of wheat will provide a convenient tool for wheat tissue culture and transformation, thereby facilitating the transformation of foreign genes into wheat. By using the mature embryos derived from 20 different wheat lines including Shi 4185, Yumai 66, Lunxuan 987, CB037, Yangmai 6, Xinchun 9, Bobwhite, Han 6172, Zheng 9023, Jimai 20, Ningchun 4, and Jing 411, the effects of some factors including inoculation methods, initiating culture media, organic additives, antioxidants, and auxins on the regeneration from the explants were evaluated. The results indicated that the scraping embryo culture was better than the whole embryo culture, the Aa medium was better than the SD2 medium and dicamba was better than 2,4-D in increasing the regeneration frequency. An Adi medium was established in this study by adding silver nitrate, cysteine, ascorbic acid, dicamba, glutamine into the Aa medium at the concentration of 4,40, 100, 2, and 5 mg L^-1, respectively. By using the Adi medium and the scraping technique, the regeneration frequencies of the mature embryos of CB037, Lunxuan 987, Hart 6172, Yangmai 6, Bobwhite, Zheng 9023, Shi 4 185, and Jimai 20 became 85.6, 60,1, 46.0, 42.1,42.0, 34.0, 33.0, and 32.0%, respectively, which were about 5-8 times higher than that obtained from the conventional culture mediums and techniques. This novel regeneration system could be helpful in wheat transformation.展开更多
基金supported by Genetically Modified Breeding Major Projects(No.2016ZX08010-002-008)the National Natural Science Foundation of China(Nos.31501239 and 31401454)
文摘Most of the important agronomic traits in crop plants, such as yield, quality and stress response, are quantitative and jointly controlled by many genomic loci or major genes. Improving these complex traits depends on the combination of beneficial alleles at the quantitative trait loci （QTLs）. However, the conventional cross breeding method is extremely time-consuming and laborious for pyramiding multiple QTLs. In certain cases, this approach might be technically difficult because of close linkage between genes separately responsible for desirable and undesirable traits.
基金This work was supported by the National Natural Science Foundation of China.
文摘We give definitions on increasing, constant and decreasing returns to scale under the generalized data envelopment analysis (GDEA) model. The GDEA model prossesses cone structures for describing evaluators’ preferences toward different decision making units (DMU) and toward different input / output categories. The GDEA model contains many important DEA models as its subclasses. Based upon the definition, we discuss and rigorously prove the necessary and sufficient conditions for a DMU to have increasing, constant and decreasing returns to scale under a GDEA model, and discuss and clarify the differences and relationships of these conditions under different subclasses of the GDEA model. Furthermore, we describe a method based on a two-stage linear program to test returns to scale properties.
基金This work was supported in part by the National Natural Science Foundation of China(collaborating with EPSRC of UK)(Nos.51361130152 and EP/L001039/1)the National Science and Technology Support Program of China(No.2013BAA01B03)Research on Reactive Power Control and Comprehensive Evaluation Technique of Large Scale Integration of Wind/Photovoltaic Power Generation(No.NY71-14-035).
文摘With the increasing integration of wind farms and electric vehicles(EVs)in power systems,voltage stability is becoming more and more serious.Based on vehicle-to-grid(V2G),an efficient power plant model of EVs(E-EPP)was developed to estimate EV charging load with available corresponding response capacity under different charging strategies.A preventive control strategy based on E-EPP was proposed to maintain the static voltage stability margin(VSM)of power system above a predefined security level.Two control modes were used including the disconnection of EV charging load(‘V1G’mode)and the discharge of stored battery energy back to power grid(‘V2G’mode).A modified IEEE 14-bus system with high penetration of wind power and EVs was used to verify the effectiveness of preventive control strategy.Simulation results showed that the proposed strategy can not only improve the static voltage stability of power system with considerable wind generation,but also guarantee the travelling comfort for EV owners.
基金funded by the National Natural Science Foundation of China (30971776)the National Transgenic Organism Research Program of China(2008ZX08010-004)
文摘Establishment of a highly efficient regeneration system for the mature embryo of wheat will provide a convenient tool for wheat tissue culture and transformation, thereby facilitating the transformation of foreign genes into wheat. By using the mature embryos derived from 20 different wheat lines including Shi 4185, Yumai 66, Lunxuan 987, CB037, Yangmai 6, Xinchun 9, Bobwhite, Han 6172, Zheng 9023, Jimai 20, Ningchun 4, and Jing 411, the effects of some factors including inoculation methods, initiating culture media, organic additives, antioxidants, and auxins on the regeneration from the explants were evaluated. The results indicated that the scraping embryo culture was better than the whole embryo culture, the Aa medium was better than the SD2 medium and dicamba was better than 2,4-D in increasing the regeneration frequency. An Adi medium was established in this study by adding silver nitrate, cysteine, ascorbic acid, dicamba, glutamine into the Aa medium at the concentration of 4,40, 100, 2, and 5 mg L^-1, respectively. By using the Adi medium and the scraping technique, the regeneration frequencies of the mature embryos of CB037, Lunxuan 987, Hart 6172, Yangmai 6, Bobwhite, Zheng 9023, Shi 4 185, and Jimai 20 became 85.6, 60,1, 46.0, 42.1,42.0, 34.0, 33.0, and 32.0%, respectively, which were about 5-8 times higher than that obtained from the conventional culture mediums and techniques. This novel regeneration system could be helpful in wheat transformation.
