In this paper,two new models suitable for power system stability analysis with considering time delays are derived.They are constraint time-delayed ordinary differential equation model(CTODE model) and constraint time...In this paper,two new models suitable for power system stability analysis with considering time delays are derived.They are constraint time-delayed ordinary differential equation model(CTODE model) and constraint time-delayed differential algebraic equation model(CTDAE model).In these two models,dimension of the time-delayed equation is significantly reduced so as to speed up the calculation efficiency.Detail derivations to their nonlinear and incremental linear forms are given.And,some of their good features are discussed.Finally,a typical time-delayed system and single-machine-infinite-bus system are selected to validate the new models through Lyapunov-Krasovskii criterion and eigenvalue locus tracing procedure.It reveals that some unnecessary calculations in the algorithm can be avoided to achieve higher efficiency based on new models.The new models and new criterion given in this paper are helpful to design wide area protectors for bulk power systems.展开更多
A new leave disease of tomato(Lycopersicon esculentum Miller) was observed in polyethylene film-covered greenhouse in Beijing,China.This disease spreaded rapidly in the greenhouse and caused serious loss of the produc...A new leave disease of tomato(Lycopersicon esculentum Miller) was observed in polyethylene film-covered greenhouse in Beijing,China.This disease spreaded rapidly in the greenhouse and caused serious loss of the production of tomatoes.In the study,a fungal strain isolated from the lesion was confirmed to be pathogen for this new disease,and identified as Myrothecium roridum Tode ex Fr.based on the morphology,cultural characters on PDA plate and sequence analysis of ribosomal DNA-ITS.This is the first report of myrothecium leaf spot on tomato occurring in commercial greenhouse in China.展开更多
通过对杨树不同品系感染水泡型溃疡病[Botryophaeria ribis(Tode)Grossenb et Buggar]情况的田间调查发现:‘16-02杨’‘欧美107杨’‘46杨’3个品系抗水泡型溃疡病,‘豫抗杨’‘16-10杨’‘16-06杨’3个品系极抗水泡型溃疡病,‘16-07...通过对杨树不同品系感染水泡型溃疡病[Botryophaeria ribis(Tode)Grossenb et Buggar]情况的田间调查发现:‘16-02杨’‘欧美107杨’‘46杨’3个品系抗水泡型溃疡病,‘豫抗杨’‘16-10杨’‘16-06杨’3个品系极抗水泡型溃疡病,‘16-07杨’‘16-08杨’高度感水泡型溃疡病。展开更多
In his new book Being and Substance： A Study of Aristotle＇s Metaphysics Z1-9, Nie Minli, taking a holistic perspective, argues that the primary substance--that is, the individual in Categories--is identical to form,...In his new book Being and Substance： A Study of Aristotle＇s Metaphysics Z1-9, Nie Minli, taking a holistic perspective, argues that the primary substance--that is, the individual in Categories--is identical to form, which is the primary substance in Metaphysics Z, and that Z3 has finished arguing what the real candidate of substance is and the inserted Z7-9 texts are the ＂core and key＂ of the entire book. In spite of his excellent scholarship and masterful interpretation of Metaphysics Z4-6, Z7, Categories 1-5 and Physics A, Nie offers insufficient textual support for his interpretation of the primary substance in Metaphysics Z and the content of Z3. Although substance is the subject （hypokeimenon） and a ＂this＂ （tode ti） in Categories, it is the ultimate subject （hypokeimenon eschaton） and a ＂this＂ （tode ti） and separable （choriston） in Metaphysics. As the ultimate subject, substance is form and matter but not the individual. As a ＂this＂ （tode ti） and separable （choriston）, substance is form; moreover, the primary substance is form. In my view, that form is substance in Z3 serves more as a plan or outline needed to prove in the following than as a definite conclusion. This article also points out that tode ti in Z8, 1033b21 refers to the individual but not the form. Homdnuma in Z9 cannot be understood as ＂sharing the same name but with different meaning,＂ but, rather, simply as ＂having the same name.＂展开更多
基金supported by Special Fund of the National Basic Research Program of China("973"Program)(Grant No.2009CB219701)National Natural Science Foundation of China(Grant No.51277128)State Grid Corporation of China(Grant No.SGCC-MPLG028-2012)
文摘In this paper,two new models suitable for power system stability analysis with considering time delays are derived.They are constraint time-delayed ordinary differential equation model(CTODE model) and constraint time-delayed differential algebraic equation model(CTDAE model).In these two models,dimension of the time-delayed equation is significantly reduced so as to speed up the calculation efficiency.Detail derivations to their nonlinear and incremental linear forms are given.And,some of their good features are discussed.Finally,a typical time-delayed system and single-machine-infinite-bus system are selected to validate the new models through Lyapunov-Krasovskii criterion and eigenvalue locus tracing procedure.It reveals that some unnecessary calculations in the algorithm can be avoided to achieve higher efficiency based on new models.The new models and new criterion given in this paper are helpful to design wide area protectors for bulk power systems.
文摘A new leave disease of tomato(Lycopersicon esculentum Miller) was observed in polyethylene film-covered greenhouse in Beijing,China.This disease spreaded rapidly in the greenhouse and caused serious loss of the production of tomatoes.In the study,a fungal strain isolated from the lesion was confirmed to be pathogen for this new disease,and identified as Myrothecium roridum Tode ex Fr.based on the morphology,cultural characters on PDA plate and sequence analysis of ribosomal DNA-ITS.This is the first report of myrothecium leaf spot on tomato occurring in commercial greenhouse in China.
文摘通过对杨树不同品系感染水泡型溃疡病[Botryophaeria ribis(Tode)Grossenb et Buggar]情况的田间调查发现:‘16-02杨’‘欧美107杨’‘46杨’3个品系抗水泡型溃疡病,‘豫抗杨’‘16-10杨’‘16-06杨’3个品系极抗水泡型溃疡病,‘16-07杨’‘16-08杨’高度感水泡型溃疡病。
文摘In his new book Being and Substance： A Study of Aristotle＇s Metaphysics Z1-9, Nie Minli, taking a holistic perspective, argues that the primary substance--that is, the individual in Categories--is identical to form, which is the primary substance in Metaphysics Z, and that Z3 has finished arguing what the real candidate of substance is and the inserted Z7-9 texts are the ＂core and key＂ of the entire book. In spite of his excellent scholarship and masterful interpretation of Metaphysics Z4-6, Z7, Categories 1-5 and Physics A, Nie offers insufficient textual support for his interpretation of the primary substance in Metaphysics Z and the content of Z3. Although substance is the subject （hypokeimenon） and a ＂this＂ （tode ti） in Categories, it is the ultimate subject （hypokeimenon eschaton） and a ＂this＂ （tode ti） and separable （choriston） in Metaphysics. As the ultimate subject, substance is form and matter but not the individual. As a ＂this＂ （tode ti） and separable （choriston）, substance is form; moreover, the primary substance is form. In my view, that form is substance in Z3 serves more as a plan or outline needed to prove in the following than as a definite conclusion. This article also points out that tode ti in Z8, 1033b21 refers to the individual but not the form. Homdnuma in Z9 cannot be understood as ＂sharing the same name but with different meaning,＂ but, rather, simply as ＂having the same name.＂
