Yihui1577 was bred after over 10 generations by crossing R16 and Yunan purple rice. Many new hybrid rice varieties have been bred with Yihui1577, of which Gangyou1577. Ilyou1577, Nyou1577 and Yixiang1577 were certifie...Yihui1577 was bred after over 10 generations by crossing R16 and Yunan purple rice. Many new hybrid rice varieties have been bred with Yihui1577, of which Gangyou1577. Ilyou1577, Nyou1577 and Yixiang1577 were certified by Sichuan Crop Variety Release Committee, Gangyou1577 and Yixiang1577 were certified by National Crop Variety Release Committee. The series varieties bred with Yihui1577 have been used widely with accumulated area of 1,200,000 ha. By using Yihui1577 as breeding material, an excellent restore line Yihui3003 and some other restore lines, such as Yihui1979 and Yihui315 with good quality and combination ability have been bred. Analysis of combination ability and stability of restore line Yihui1577 was made by using agricultural experimentation and statistical approach. The combination ability analysis was made by not complete dual crossing method with 4 CMS lines and 6 restorer lines. It shows that the general combination ability effect value of Yihui1577 is 0.226, while Minghui63 is -0.113. So the general combination ability of Yihui1577 is prior to that of Minghui63. Stability analysis shows that the F value of Gangyou1577 is 1.81378, while Sanyou63 is 1.40327, both doesn＇t reach significant level. So Gangyou1577 has the same stability as Sanyou63.The same conclusion is got in the stability analysis of the breeds of II you 1577, Yixiang1577, Nyou 1577 and so on.展开更多
High-temperature Ni-based alloys are widely used in the aerospace field due to their excellent properties,but the shortcomings of brittle fracture at the grain boundaries and poor plasticity at room temperature also l...High-temperature Ni-based alloys are widely used in the aerospace field due to their excellent properties,but the shortcomings of brittle fracture at the grain boundaries and poor plasticity at room temperature also limit their development to a certain extent.Researchers found that there areγ′precipitation phases similar to Ni_(3)Al in Pt-Al based alloys.In this paper,the CASTEP code of Materials Studio software package is used to simulate the thermal and mechanical properties ofγ′-Pt_(3)Al phase andγ′-Ni_(3)Al phase.By comparing the performance characteristics of the electronic structure,mechanical properties and point defect structure of the two,it is found that the stability,elastic deformation resistance and high temperature creep resistance of theγ′-Pt_(3)Al phase are better than those of theγ′-Ni_(3)Al phase.This will provide theoretical guidance for promoting the development of Pt-Al-based high-temperature materials.展开更多
Based on the theory of data envelopment analysis, this paper sets up the super-efficiency data envelopment analysis （DEA） model. It makes use of the model to evaluate efficiency of equipment shared by universities i...Based on the theory of data envelopment analysis, this paper sets up the super-efficiency data envelopment analysis （DEA） model. It makes use of the model to evaluate efficiency of equipment shared by universities in Tianjin. It explored database of many universities and put forward suggestions to improve the efficiency of equipment shared by universities at present.展开更多
基金The study is approved by the state 863 program in China (the program No.2002AA2070002)and Sichuan province 15 rice breeding key project.
文摘Yihui1577 was bred after over 10 generations by crossing R16 and Yunan purple rice. Many new hybrid rice varieties have been bred with Yihui1577, of which Gangyou1577. Ilyou1577, Nyou1577 and Yixiang1577 were certified by Sichuan Crop Variety Release Committee, Gangyou1577 and Yixiang1577 were certified by National Crop Variety Release Committee. The series varieties bred with Yihui1577 have been used widely with accumulated area of 1,200,000 ha. By using Yihui1577 as breeding material, an excellent restore line Yihui3003 and some other restore lines, such as Yihui1979 and Yihui315 with good quality and combination ability have been bred. Analysis of combination ability and stability of restore line Yihui1577 was made by using agricultural experimentation and statistical approach. The combination ability analysis was made by not complete dual crossing method with 4 CMS lines and 6 restorer lines. It shows that the general combination ability effect value of Yihui1577 is 0.226, while Minghui63 is -0.113. So the general combination ability of Yihui1577 is prior to that of Minghui63. Stability analysis shows that the F value of Gangyou1577 is 1.81378, while Sanyou63 is 1.40327, both doesn＇t reach significant level. So Gangyou1577 has the same stability as Sanyou63.The same conclusion is got in the stability analysis of the breeds of II you 1577, Yixiang1577, Nyou 1577 and so on.
文摘High-temperature Ni-based alloys are widely used in the aerospace field due to their excellent properties,but the shortcomings of brittle fracture at the grain boundaries and poor plasticity at room temperature also limit their development to a certain extent.Researchers found that there areγ′precipitation phases similar to Ni_(3)Al in Pt-Al based alloys.In this paper,the CASTEP code of Materials Studio software package is used to simulate the thermal and mechanical properties ofγ′-Pt_(3)Al phase andγ′-Ni_(3)Al phase.By comparing the performance characteristics of the electronic structure,mechanical properties and point defect structure of the two,it is found that the stability,elastic deformation resistance and high temperature creep resistance of theγ′-Pt_(3)Al phase are better than those of theγ′-Ni_(3)Al phase.This will provide theoretical guidance for promoting the development of Pt-Al-based high-temperature materials.
文摘Based on the theory of data envelopment analysis, this paper sets up the super-efficiency data envelopment analysis （DEA） model. It makes use of the model to evaluate efficiency of equipment shared by universities in Tianjin. It explored database of many universities and put forward suggestions to improve the efficiency of equipment shared by universities at present.
