In this paper,the I-ring which satisfies almost descending chain conditions (shorten writting A. D. C. C) on principal left ideals is studied. Two main results are gaven: (1) I-ring which satisfies A. D.C. C on princi...In this paper,the I-ring which satisfies almost descending chain conditions (shorten writting A. D. C. C) on principal left ideals is studied. Two main results are gaven: (1) I-ring which satisfies A. D.C. C on principal left ideals is Boolen. (2) Ring with identity whose principal left ideals satisfy A. D. C. C and of which each element except identity is a left zero-divisor, is Boolean.These results generalize the results of [1],[2] and [3].展开更多
Through theoretical analyses of the Shockley equation and the difference between a practical P-N junction and its ideal model, the mathematical models of P-N junction and solar cells had been obtained. With Matlab sof...Through theoretical analyses of the Shockley equation and the difference between a practical P-N junction and its ideal model, the mathematical models of P-N junction and solar cells had been obtained. With Matlab software, the V-I characteristics of diodes and solar cells were simulated, and a computer simulation model of the solar cells based on P-N junction was also established. Based on the simulation model, the influences of solar cell’s internal resistances on open-circuit voltage and short-circuit current under certain illumination were numerically analyzed and solved. The simulation results showed that the equivalent series resistance and shunt resistance could strongly affect the V-I characteristics of solar cell, but their influence styles were different.展开更多
A copper-catalyzed highly stereoselective cyclopropanation of 1,2-disubstituted olefins with α-nitrodiazo acetates has been developed, giving the desired products in up to 97 % yields, up to 〉99/1 dr and up to 98 % ...A copper-catalyzed highly stereoselective cyclopropanation of 1,2-disubstituted olefins with α-nitrodiazo acetates has been developed, giving the desired products in up to 97 % yields, up to 〉99/1 dr and up to 98 % ee, which provides an efficient access to the synthesis of optical active cyclopropane α-amino acids and unnatural α-amino acid derivatives.展开更多
文摘In this paper,the I-ring which satisfies almost descending chain conditions (shorten writting A. D. C. C) on principal left ideals is studied. Two main results are gaven: (1) I-ring which satisfies A. D.C. C on principal left ideals is Boolen. (2) Ring with identity whose principal left ideals satisfy A. D. C. C and of which each element except identity is a left zero-divisor, is Boolean.These results generalize the results of [1],[2] and [3].
文摘Through theoretical analyses of the Shockley equation and the difference between a practical P-N junction and its ideal model, the mathematical models of P-N junction and solar cells had been obtained. With Matlab software, the V-I characteristics of diodes and solar cells were simulated, and a computer simulation model of the solar cells based on P-N junction was also established. Based on the simulation model, the influences of solar cell’s internal resistances on open-circuit voltage and short-circuit current under certain illumination were numerically analyzed and solved. The simulation results showed that the equivalent series resistance and shunt resistance could strongly affect the V-I characteristics of solar cell, but their influence styles were different.
基金supported by the National Natural Science Foundation of China(21421091,21432011 and21272250)the Chinese Academy of Sciences
文摘A copper-catalyzed highly stereoselective cyclopropanation of 1,2-disubstituted olefins with α-nitrodiazo acetates has been developed, giving the desired products in up to 97 % yields, up to 〉99/1 dr and up to 98 % ee, which provides an efficient access to the synthesis of optical active cyclopropane α-amino acids and unnatural α-amino acid derivatives.
