The 16 tree species on Northeast China Transect (NECT) were analyzed from the change of geographical distribution, frequency and dominance pattern and the spatial correlation at landscape scale in 1986 and 1994. Pin...The 16 tree species on Northeast China Transect (NECT) were analyzed from the change of geographical distribution, frequency and dominance pattern and the spatial correlation at landscape scale in 1986 and 1994. Pinus koraiensis Sieb. et Zucc. and Fraxinus rhynchophylla Hemsl. had spread rapidly towards west and east, respectively. The frontier form of species had close relation with its movement. The patch size of Pinus koraiensis , Populus davidiana Dode., Phellodendron amurense Rupr., Juglans mandshurica Maxim., Fraxinus mandshurica Rupr., Betula dahurica Pall., Picea koraiensis Nakai, Abies nephrolepis Maxim. and Larix olgeusis var. koreana Nakai decreased, however, Quercus mongolica Fisch., Betula costata Trautv., Acer mono Maxim., Tilia spp., Ulmus spp., Betula platyphylla Suk. and Fraxinus rhynchophylla increased. The frequency pattern of Populus davidiana , Betula platyphylla , Fraxinus rhynchophylla and Betula dahurica changed significantly. The dominance pattern of Populus davidiana , Tilia spp., Juglans mandshurica , Betula platyphylla , Betula dahurica and Abies nephrolepis changed significantly. The spatial correlation between Quercus mongolica and Betula dahurica , Betula costata and Picea spp., Betula costata and Abies nephrolepis , Picea spp. and Abies nephrolepis declined, however, the spatial correlation between Larix spp. and Betula platyphylla , Acer mono and Ulmus spp. increased.展开更多
Singchia Z. J. Liu ＆ L. J. Chen, a new orchid genus, is established based on the new species S. malipoensis Z. J. Liu ＆ L. J. Chen found in southeast Yunnan, China. The new genus is related to Pteroceras, from which...Singchia Z. J. Liu ＆ L. J. Chen, a new orchid genus, is established based on the new species S. malipoensis Z. J. Liu ＆ L. J. Chen found in southeast Yunnan, China. The new genus is related to Pteroceras, from which it differs by having a lip with its basal margins immovably adnate to the lower part of the pendent column foot, a thin-walled spur, and very unequally and deeply split pollinia, each with a distinct caudicle. In addition to a discussion on Ascocentrum pusillum, a species of questionable placement, another new genus, namely Gunnaria S. C. Chen ex Z. J. Liu ＆ L. J. Chen, is set up and a new combination, namely G. pusilla （Aver.） Z. J. Liu ＆ L. J. Chen, is made. The new genus Gunnaria differs from its allyAscocentrum by having a cross-shaped pollinarium, sulcate or split pollinia, each with a distinct caudicle attached to a common linear stipe much longer than either pollinia or viscidium, and strongly incurved side lobes of the lip.展开更多
Dear Editor,Depending on the perceived threat in the environment,organisms can express a broad spectrum of behaviors,ranging from exploration to defensive behaviors[1,2],such as fear response and avoidance.Generalizat...Dear Editor,Depending on the perceived threat in the environment,organisms can express a broad spectrum of behaviors,ranging from exploration to defensive behaviors[1,2],such as fear response and avoidance.Generalization of fear memory can generate anxiety-related disorders that afflict 10%-30%of individuals worldwide,especially during the epidemic situation[3,4].展开更多
The authors regret the omission of supplementary fi les in the original artide.Download all supplementary fles included with this artide.The author would like to apologise for any inconvenience caused.
This paper describes a stabilization effect after installating an adjustable speed generator (ASG) in a multi machine power system. A personal computer based ASG module has been de veloped for the simulations in...This paper describes a stabilization effect after installating an adjustable speed generator (ASG) in a multi machine power system. A personal computer based ASG module has been de veloped for the simulations in parallel with the analog power system simulator i n the Research Laboratory of the Kyushu Electric Power Co. The three phase ins t antaneous value based ASG model has been developed in the Matlab/Simulink envir onment for its detailed and real time simulations, which have been performed on a digital signal processor (DSP) board with AD and DA conversion interfaces inst alled in a personal computer (PC). Simulational results indicate the hig hly improved overall stability of the multi machine power system after installa ting the ASG.展开更多
Type genus:Aclistochara Peck,1937 emend.Peck,1957 Diagnosis:Gyrogonites composed of five sinistral spiral cells,apicalpart truncated or contracted forming a short neck,summits flat.Spiralcells become distinctly thinne...Type genus:Aclistochara Peck,1937 emend.Peck,1957 Diagnosis:Gyrogonites composed of five sinistral spiral cells,apicalpart truncated or contracted forming a short neck,summits flat.Spiralcells become distinctly thinner and narrower in the apical periphery,formingapical peripheral depression of various depths.The apical centre is eithermarked by an apical rosette formed by inflation of spital ends,orl thin andflat when the spiral ends are not inflated,without apical orifice and utricle.展开更多
The Sihui Furniture General Factory issituated in the Sihui County Town ofGuangdong Province.It is a state-runenterprise with fixed assets of RMB 15 millionand 400 staff and workers. "Quality first and customers ...The Sihui Furniture General Factory issituated in the Sihui County Town ofGuangdong Province.It is a state-runenterprise with fixed assets of RMB 15 millionand 400 staff and workers. "Quality first and customers supreme"and"abiding by contracts and honouringpromises"are the factory’s aims.The factoryhas built up a reputation for its completequality inspection system,rigid quality controlprocess and warm after-sales service.Thefactory has been awarded the title ofGuangdong Provincial Advanced Enterprise. The Jiahui brand high-spring mattressis the factory’s major product.There are 210springs per square metre of the mattress.Each spring is heat-treated through展开更多
Spectral data can potentially offer a rapid assessment of nutrients in leaves and reveal information about the geologic history of the soil.This study evaluated the capability of the partial least squares regression(P...Spectral data can potentially offer a rapid assessment of nutrients in leaves and reveal information about the geologic history of the soil.This study evaluated the capability of the partial least squares regression(PLSR)for estimating foliar macro-and micronutrients(Ca,Mg,K,P,Mn,and Zn)using spectral data(400 to 2,450 nm).First,filter-based wavelength selection was conducted to reduce the independent variables.PLSR performance was then assessed across 4 geologic materials(coarse glacial till,glaciofluvial,melt-out till,and outwash)and 4 dominant tree genera(Acer,Betula,Fagus,and Quercus)in the northeastern United States.The spectral ranges 400 to 500 nm and 1,800 to 2,450 nm were found to be the most important spectral regions for estimating foliar nutrient concentrations.The developed PLSR model predicted 6 foliar nutrients with moderate to high accuracy(adjusted R^(2) from 0.60 to 0.75).Foliar macronutrient concentrations were estimated with higher accuracy(mean adj.R^(2)=0.69)than micronutrient concentrations(mean adj.R^(2)=0.635).The prediction for the individual tree genera group and the individual geologic materials group outperformed the combined group;for instance,the adj.R^(2) for estimating Ca and P was 39%higher for American beech(Fagus grandifolia)than all tree genera combined.Spectral measurements combined with wavelength selection and PLSR models can potentially be used to quantify foliar macro-and micronutrients at regional scales,and taking into account geologic materials and tree genera will improve this prediction.展开更多
Monospecific and bispecific genera are of special concern as they represent unique phylogenetic/evolutionary trajectories within larger clades.In addition,as phylogenetically older taxa are supposed to be exposed to h...Monospecific and bispecific genera are of special concern as they represent unique phylogenetic/evolutionary trajectories within larger clades.In addition,as phylogenetically older taxa are supposed to be exposed to higher rarity and extinction risk,monospecific and bispecific genera may be intrinsically more prone to extinction risks than multispecies genera,although extinction risks also depend on the ecological and biological strategy of the species.Here,the distribution across biogeographical zones and the levels of threat to 2 speciose orders of mammals(monospecific and bispecific genera of Rodentia and Soricomorpha)are investigated in order to highlight major patterns at the worldwide scale.In Rodentia,39.7%of the genera(n=490)were monospecific and 17.9%were bispecific.In Soricomorpha,44.4%of the total genera(n=45)were monospecific and 15%were bispecific.There was a positive correlation between the number of monospecific genera and the total number of genera per family.Peaks of monospecific and bispecific genera richness were observed in Neotropical,Oriental and Afrotropical regions in rodents and in the Palearctic region in soricomorphs.Range size was significantly uneven across biogeographic region in rodents(with larger ranges in Nearctic and Oriental regions and smaller ranges in the Australian region),but there was no difference across biogeographic regions in terms of range size in soricomorphs.Most of the monospecific and bispecific genera occurred in forest habitat in both taxa.The frequency distribution of the monospecific and bispecific genera across IUCN categories did not differ significantly from the expected pattern using the total rodent genera and the multispecies genera.展开更多
Let D be a nonsquare integer and p be an odd prime with p(?)D. The equation x^2-D=p^n, x>0, n>0 (1) is usually called the generalized Ramanujan-Nagell equation. For this equation, there are many related works wr...Let D be a nonsquare integer and p be an odd prime with p(?)D. The equation x^2-D=p^n, x>0, n>0 (1) is usually called the generalized Ramanujan-Nagell equation. For this equation, there are many related works written by Alter and Kubota, Brown, Cohen and lnkeri. In this letter, we shall prove the展开更多
We use the Atiyah-Bott-Segal-Singer Lefschetz fixed point fornula to calculate the Hirzebruch Xy genus Xy(S[n]), where S[n] is the Hilbert scheme of points of length n of a surface 5. Combinatorial interpretation of t...We use the Atiyah-Bott-Segal-Singer Lefschetz fixed point fornula to calculate the Hirzebruch Xy genus Xy(S[n]), where S[n] is the Hilbert scheme of points of length n of a surface 5. Combinatorial interpretation of the weights of the fixed points of the natural torus action on (C2)[n] is used. This is the first step to prove a conjectural formula about the elliptic genus of the Hilbert schemes.展开更多
文摘The 16 tree species on Northeast China Transect (NECT) were analyzed from the change of geographical distribution, frequency and dominance pattern and the spatial correlation at landscape scale in 1986 and 1994. Pinus koraiensis Sieb. et Zucc. and Fraxinus rhynchophylla Hemsl. had spread rapidly towards west and east, respectively. The frontier form of species had close relation with its movement. The patch size of Pinus koraiensis , Populus davidiana Dode., Phellodendron amurense Rupr., Juglans mandshurica Maxim., Fraxinus mandshurica Rupr., Betula dahurica Pall., Picea koraiensis Nakai, Abies nephrolepis Maxim. and Larix olgeusis var. koreana Nakai decreased, however, Quercus mongolica Fisch., Betula costata Trautv., Acer mono Maxim., Tilia spp., Ulmus spp., Betula platyphylla Suk. and Fraxinus rhynchophylla increased. The frequency pattern of Populus davidiana , Betula platyphylla , Fraxinus rhynchophylla and Betula dahurica changed significantly. The dominance pattern of Populus davidiana , Tilia spp., Juglans mandshurica , Betula platyphylla , Betula dahurica and Abies nephrolepis changed significantly. The spatial correlation between Quercus mongolica and Betula dahurica , Betula costata and Picea spp., Betula costata and Abies nephrolepis , Picea spp. and Abies nephrolepis declined, however, the spatial correlation between Larix spp. and Betula platyphylla , Acer mono and Ulmus spp. increased.
基金supported financially by the National Program for Wild Life Conservation and Nature Reserve Construction,China,and by the Science & Technology Plan of Shenzhen,China (SYF 200646408).
文摘Singchia Z. J. Liu ＆ L. J. Chen, a new orchid genus, is established based on the new species S. malipoensis Z. J. Liu ＆ L. J. Chen found in southeast Yunnan, China. The new genus is related to Pteroceras, from which it differs by having a lip with its basal margins immovably adnate to the lower part of the pendent column foot, a thin-walled spur, and very unequally and deeply split pollinia, each with a distinct caudicle. In addition to a discussion on Ascocentrum pusillum, a species of questionable placement, another new genus, namely Gunnaria S. C. Chen ex Z. J. Liu ＆ L. J. Chen, is set up and a new combination, namely G. pusilla （Aver.） Z. J. Liu ＆ L. J. Chen, is made. The new genus Gunnaria differs from its allyAscocentrum by having a cross-shaped pollinarium, sulcate or split pollinia, each with a distinct caudicle attached to a common linear stipe much longer than either pollinia or viscidium, and strongly incurved side lobes of the lip.
基金supported by grants from the National Natural Science Foundation of China(81870852 and 82171199)the Qing Lan Project of Jiangsu Province,the Education Department of Jiangsu Province(18KJA320007)+3 种基金the Natural Science Foundation of Jiangsu Province(BK20181146 and BK20210911)the Postgraduate Research&Practice Innovation Program of Jiangsu Province(KYCX21_2706,KYCX21_2703,and YCX21_2717)the Program on Basic Research Projects of Xuzhou City(KC21048)the Special Funds for Anesthesia Medical Research of Jiangsu Medical Association SYH-32021-0040(2021035).
文摘Dear Editor,Depending on the perceived threat in the environment,organisms can express a broad spectrum of behaviors,ranging from exploration to defensive behaviors[1,2],such as fear response and avoidance.Generalization of fear memory can generate anxiety-related disorders that afflict 10%-30%of individuals worldwide,especially during the epidemic situation[3,4].
文摘The authors regret the omission of supplementary fi les in the original artide.Download all supplementary fles included with this artide.The author would like to apologise for any inconvenience caused.
文摘This paper describes a stabilization effect after installating an adjustable speed generator (ASG) in a multi machine power system. A personal computer based ASG module has been de veloped for the simulations in parallel with the analog power system simulator i n the Research Laboratory of the Kyushu Electric Power Co. The three phase ins t antaneous value based ASG model has been developed in the Matlab/Simulink envir onment for its detailed and real time simulations, which have been performed on a digital signal processor (DSP) board with AD and DA conversion interfaces inst alled in a personal computer (PC). Simulational results indicate the hig hly improved overall stability of the multi machine power system after installa ting the ASG.
文摘Type genus:Aclistochara Peck,1937 emend.Peck,1957 Diagnosis:Gyrogonites composed of five sinistral spiral cells,apicalpart truncated or contracted forming a short neck,summits flat.Spiralcells become distinctly thinner and narrower in the apical periphery,formingapical peripheral depression of various depths.The apical centre is eithermarked by an apical rosette formed by inflation of spital ends,orl thin andflat when the spiral ends are not inflated,without apical orifice and utricle.
文摘The Sihui Furniture General Factory issituated in the Sihui County Town ofGuangdong Province.It is a state-runenterprise with fixed assets of RMB 15 millionand 400 staff and workers. "Quality first and customers supreme"and"abiding by contracts and honouringpromises"are the factory’s aims.The factoryhas built up a reputation for its completequality inspection system,rigid quality controlprocess and warm after-sales service.Thefactory has been awarded the title ofGuangdong Provincial Advanced Enterprise. The Jiahui brand high-spring mattressis the factory’s major product.There are 210springs per square metre of the mattress.Each spring is heat-treated through
基金supported by the University of Massachusetts Amherst,College of Natural Sciences by Award 1801 to J.B.R.
文摘Spectral data can potentially offer a rapid assessment of nutrients in leaves and reveal information about the geologic history of the soil.This study evaluated the capability of the partial least squares regression(PLSR)for estimating foliar macro-and micronutrients(Ca,Mg,K,P,Mn,and Zn)using spectral data(400 to 2,450 nm).First,filter-based wavelength selection was conducted to reduce the independent variables.PLSR performance was then assessed across 4 geologic materials(coarse glacial till,glaciofluvial,melt-out till,and outwash)and 4 dominant tree genera(Acer,Betula,Fagus,and Quercus)in the northeastern United States.The spectral ranges 400 to 500 nm and 1,800 to 2,450 nm were found to be the most important spectral regions for estimating foliar nutrient concentrations.The developed PLSR model predicted 6 foliar nutrients with moderate to high accuracy(adjusted R^(2) from 0.60 to 0.75).Foliar macronutrient concentrations were estimated with higher accuracy(mean adj.R^(2)=0.69)than micronutrient concentrations(mean adj.R^(2)=0.635).The prediction for the individual tree genera group and the individual geologic materials group outperformed the combined group;for instance,the adj.R^(2) for estimating Ca and P was 39%higher for American beech(Fagus grandifolia)than all tree genera combined.Spectral measurements combined with wavelength selection and PLSR models can potentially be used to quantify foliar macro-and micronutrients at regional scales,and taking into account geologic materials and tree genera will improve this prediction.
文摘广义的斜蒴苣苔属(Loxocarpus R.Br.sensu lato)为马来西亚植物区系和巽他古陆的特有类群,其生态习性、营养器官和蒴果形态高度相似,但花部器官却显示出一定的分化和多样性。分子系统学证据显示,该属实际上是一个多系群。根据形态性状特异性组合,结合分子系统学证据,该文将广义的斜蒴苣苔属拆分为3个属,包括狭义的斜蒴苣苔属(Loxocarpus sensu stricto)及姚氏苣苔属(Yaoa)和斜钟花属(Paraloxocarpus)2新属。该文提供了3个属的检索表和描述,对相关的21种做出新组合。
文摘Monospecific and bispecific genera are of special concern as they represent unique phylogenetic/evolutionary trajectories within larger clades.In addition,as phylogenetically older taxa are supposed to be exposed to higher rarity and extinction risk,monospecific and bispecific genera may be intrinsically more prone to extinction risks than multispecies genera,although extinction risks also depend on the ecological and biological strategy of the species.Here,the distribution across biogeographical zones and the levels of threat to 2 speciose orders of mammals(monospecific and bispecific genera of Rodentia and Soricomorpha)are investigated in order to highlight major patterns at the worldwide scale.In Rodentia,39.7%of the genera(n=490)were monospecific and 17.9%were bispecific.In Soricomorpha,44.4%of the total genera(n=45)were monospecific and 15%were bispecific.There was a positive correlation between the number of monospecific genera and the total number of genera per family.Peaks of monospecific and bispecific genera richness were observed in Neotropical,Oriental and Afrotropical regions in rodents and in the Palearctic region in soricomorphs.Range size was significantly uneven across biogeographic region in rodents(with larger ranges in Nearctic and Oriental regions and smaller ranges in the Australian region),but there was no difference across biogeographic regions in terms of range size in soricomorphs.Most of the monospecific and bispecific genera occurred in forest habitat in both taxa.The frequency distribution of the monospecific and bispecific genera across IUCN categories did not differ significantly from the expected pattern using the total rodent genera and the multispecies genera.
文摘Let D be a nonsquare integer and p be an odd prime with p(?)D. The equation x^2-D=p^n, x>0, n>0 (1) is usually called the generalized Ramanujan-Nagell equation. For this equation, there are many related works written by Alter and Kubota, Brown, Cohen and lnkeri. In this letter, we shall prove the
文摘We use the Atiyah-Bott-Segal-Singer Lefschetz fixed point fornula to calculate the Hirzebruch Xy genus Xy(S[n]), where S[n] is the Hilbert scheme of points of length n of a surface 5. Combinatorial interpretation of the weights of the fixed points of the natural torus action on (C2)[n] is used. This is the first step to prove a conjectural formula about the elliptic genus of the Hilbert schemes.
