The concept of pseudo orbital has been proposed, which includes the interactions of all the orbitals and extends the applicable limit of Fukui's frontier orbitals. An example shows that the pseudo orbital reactivi...The concept of pseudo orbital has been proposed, which includes the interactions of all the orbitals and extends the applicable limit of Fukui's frontier orbitals. An example shows that the pseudo orbital reactivity indexes are probably able to explain more complicated phenomena in chemical reactions.展开更多
Waterlogging is becoming an obvious constraint on food production due to the frequent occurrence of extremely high-level rainfall events.Leaf water content(LWC)is an important waterlogging indicator,and hyperspectral ...Waterlogging is becoming an obvious constraint on food production due to the frequent occurrence of extremely high-level rainfall events.Leaf water content(LWC)is an important waterlogging indicator,and hyperspectral remote sensing provides a non-destructive,real-time and reliable method to determine LWC.Thus,based on a pot experiment,winter wheat was subjected to different gradients of waterlogging stress at the jointing stage.Leaf hyperspectral data and LWC were collected every 7 days after waterlogging treatment until the winter wheat was mature.Combined with methods such as vegetation index construction,correlation analysis,regression analysis,BP neural network(BPNN),etc.,we found that the effect of waterlogging stress on LWC had the characteristics of hysteresis and all waterlogging stress led to the decrease of LWC.LWC decreased faster under severe stress than under slight stress,but the effect of long-term slight stress was greater than that of short-term severe stress.The sensitive spectral bands of LWC were located in the visible(VIS,400–780 nm)and short-wave infrared(SWIR,1400–2500 nm)regions.The BPNN Model with the original spectrum at 648 nm,the first derivative spectrum at 500 nm,the red edge position(λr),the new vegetation index RVI(437,466),NDVI(437,466)and NDVI´(747,1956)as independent variables was the best model for inverting the LWC of waterlogging in winter wheat(modeling set:R^(2)=0.889,RMSE=0.138;validation set:R^(2)=0.891,RMSE=0.518).These results have important theoretical significance and practical application value for the precise control of waterlogging stress.展开更多
. Applied Mathematics A Journal of Chinese Universities, abbreviated to Appl. Math.-- JCU, is a nationwide journal sponsored by Zhejiang University' The Journal aims at issuing academic works in Applied Mathematic.... Applied Mathematics A Journal of Chinese Universities, abbreviated to Appl. Math.-- JCU, is a nationwide journal sponsored by Zhejiang University' The Journal aims at issuing academic works in Applied Mathematics: original theoretical and (or) methodological research results, and innovative applications in practical fields. From 1994 on, one volume will be publishedper annum,consisting of four issues in chinese, appeared quarterly as Ser. A,and four issues inEnglish, appeared quarterly as Ser. B. Contents in the two series will'not overlap. The Journal isdistributed domestically and abroad.2. Instructions to author(s)Appl. Math. -- JCU Ser. B publishes full length papers. In view of the high cost of printing, authors should keep their papers as short as are consistent with clarity' Unnecessary introductory material should be avoided. Graphical presentation of information should be confined toas few separate diagrams as are practicable. The rules of grammar should be observed.The submission of an article will be taken to indicate that it has not been and will not be submitted for publication elsewhere.Script Requirements for All ArticlesManuscript: The manuscript must be typed in English double--spaced on one side of A4 goodquality white paper. The maximum length of an article is 15 pages, including diagrams and tables. Two copies of an article are reguired for submission (not to be returned).Abstract A short Abstract not exceeding 200 words should appear at the beginning of the paper after the title, name (s) of author (s), affiliation(s) and address (es). It should contain no reference and mathematical symbols should be kept to a minumum.展开更多
In April 2015,the MIIT issued the No.127document,proposing an equivalent or decrement replacement system for the aluminum industry.According to asianmetal.cn,until May 15,China’s total aluminum capacity replacement i...In April 2015,the MIIT issued the No.127document,proposing an equivalent or decrement replacement system for the aluminum industry.According to asianmetal.cn,until May 15,China’s total aluminum capacity replacement index展开更多
文摘The concept of pseudo orbital has been proposed, which includes the interactions of all the orbitals and extends the applicable limit of Fukui's frontier orbitals. An example shows that the pseudo orbital reactivity indexes are probably able to explain more complicated phenomena in chemical reactions.
基金This work was supported by the National Key Research and Development Program of China(2016YFD0200600,2016YFD0200601)the Key Research and Development Program of Hebei Province,China(19227407D)+1 种基金the Central Public-interest Scientific Institution Basal Research Fund(JBYW-AII-2020-29,JBYW-AII-2020-30)the Technology Innovation Project Fund of Chinese Academy of Agricultural Sciences(CAAS-ASTIP-2020-AII).
文摘Waterlogging is becoming an obvious constraint on food production due to the frequent occurrence of extremely high-level rainfall events.Leaf water content(LWC)is an important waterlogging indicator,and hyperspectral remote sensing provides a non-destructive,real-time and reliable method to determine LWC.Thus,based on a pot experiment,winter wheat was subjected to different gradients of waterlogging stress at the jointing stage.Leaf hyperspectral data and LWC were collected every 7 days after waterlogging treatment until the winter wheat was mature.Combined with methods such as vegetation index construction,correlation analysis,regression analysis,BP neural network(BPNN),etc.,we found that the effect of waterlogging stress on LWC had the characteristics of hysteresis and all waterlogging stress led to the decrease of LWC.LWC decreased faster under severe stress than under slight stress,but the effect of long-term slight stress was greater than that of short-term severe stress.The sensitive spectral bands of LWC were located in the visible(VIS,400–780 nm)and short-wave infrared(SWIR,1400–2500 nm)regions.The BPNN Model with the original spectrum at 648 nm,the first derivative spectrum at 500 nm,the red edge position(λr),the new vegetation index RVI(437,466),NDVI(437,466)and NDVI´(747,1956)as independent variables was the best model for inverting the LWC of waterlogging in winter wheat(modeling set:R^(2)=0.889,RMSE=0.138;validation set:R^(2)=0.891,RMSE=0.518).These results have important theoretical significance and practical application value for the precise control of waterlogging stress.
文摘. Applied Mathematics A Journal of Chinese Universities, abbreviated to Appl. Math.-- JCU, is a nationwide journal sponsored by Zhejiang University' The Journal aims at issuing academic works in Applied Mathematics: original theoretical and (or) methodological research results, and innovative applications in practical fields. From 1994 on, one volume will be publishedper annum,consisting of four issues in chinese, appeared quarterly as Ser. A,and four issues inEnglish, appeared quarterly as Ser. B. Contents in the two series will'not overlap. The Journal isdistributed domestically and abroad.2. Instructions to author(s)Appl. Math. -- JCU Ser. B publishes full length papers. In view of the high cost of printing, authors should keep their papers as short as are consistent with clarity' Unnecessary introductory material should be avoided. Graphical presentation of information should be confined toas few separate diagrams as are practicable. The rules of grammar should be observed.The submission of an article will be taken to indicate that it has not been and will not be submitted for publication elsewhere.Script Requirements for All ArticlesManuscript: The manuscript must be typed in English double--spaced on one side of A4 goodquality white paper. The maximum length of an article is 15 pages, including diagrams and tables. Two copies of an article are reguired for submission (not to be returned).Abstract A short Abstract not exceeding 200 words should appear at the beginning of the paper after the title, name (s) of author (s), affiliation(s) and address (es). It should contain no reference and mathematical symbols should be kept to a minumum.
文摘In April 2015,the MIIT issued the No.127document,proposing an equivalent or decrement replacement system for the aluminum industry.According to asianmetal.cn,until May 15,China’s total aluminum capacity replacement index
