Bark beetle species in natural stands of spruce, Picea crassifolia （Kom.） were investigated in Maixiu Forest Park, Qinghai Province, northwest China, during 2005 and 2007. Two pioneer Ips species, Ips nitidus Eggers...Bark beetle species in natural stands of spruce, Picea crassifolia （Kom.） were investigated in Maixiu Forest Park, Qinghai Province, northwest China, during 2005 and 2007. Two pioneer Ips species, Ips nitidus Eggers and Ips shangrila Cognato and Sun were found. I. nitidus occurs naturally in northwest China. I. shangrila is a new species in the world. In the past, it was confused with I. mannsfeldi Wachtl in China. The damage of these two Ips species has been very severe in Maixiu and the morphological and bio-logical characteristics were studied. I. nitidus starts to fly in early May and prefers the mid to lower part of the host tree to colonize as its habitat. I. shangrila always infests from the top of the trunk, especially in branches larger than 3 cm in diameter in the crowns and sometimes even colonizes entire young trees. The two Ips species are the most destructive secondary bark beetles on P. crassifolia and always cause mortality of trees by their cooperation.展开更多
In the present work,the focus has been shifted to the relationship between the PANI morphology and the physicochemical properties,controlled by the amount of added ionic liquids,of the polymerization medium instead of...In the present work,the focus has been shifted to the relationship between the PANI morphology and the physicochemical properties,controlled by the amount of added ionic liquids,of the polymerization medium instead of focusing on the structure of the ionic liquids as used to be in the litterature.For that reason,PANI has been synthesized in different weight ratio of[Pyrr][PTS]/water following the standard experimental process.The addition of[Pyrr][PTS]into the polymerization medium controls the morphology of PANI without affecting its structure.Moreover,[Pyrr][PTS]promotes a viscous reaction system without the need of an external source.The viscosity of the polymerization system restricts the diffusion of species that leads to the predominance of the homogeneous nucleation mode during the course of polymerization and,thus,nanostructuring of PANI morphology.As for the ionic conductivity,it reflects the mobility of the ions of the polymerization medium and,thus,the way of its interference with the formed PANI that affects the arrangement and the shape of formed PANI fibers.This relationship between PANI morphology and the physicochemical properties,adjusted by adding ionic liquids,of the polymerization medium is prelaminar and promising.The effect of the ionic liquids on the viscosity as well as on the mobility of the polymerization medium have to be taken into consideration to choose the ionic liquids,which lead to the PANI with desired morphology.展开更多
The classification of seedlings is important to ensure the viability of seedlings after transplantation and is acknowledged as a key factor in forestation and environmental improvement. Based on numerous papers on aut...The classification of seedlings is important to ensure the viability of seedlings after transplantation and is acknowledged as a key factor in forestation and environmental improvement. Based on numerous papers on automatic seedling classification (ASC), the seedling grading theory, traditional grading methods, the background and the proceeding of ASC techniques are described. The automation of the measurement of seedling morphological characteristics by photoelectric meters and computer vision is studied, and the automatic methods of the current grading systems are described respectively. And the further researches on ASC by computer vision are proposed.展开更多
Filtering capacitor with compact configuration and a wide range of operating voltage has been attracting increasing attention for the smooth conversion of the electric signal in modern circuits.Lossless integration of...Filtering capacitor with compact configuration and a wide range of operating voltage has been attracting increasing attention for the smooth conversion of the electric signal in modern circuits.Lossless integration of capacitor units can be regarded as one of the efficient ways to achieve a wider voltage range,which has not yet been fully conquered due to the lack of rational designs of the electrode structure and integration technology.This study presents an alternatingly stacked assemble technology to conveniently fabricate compact aqueous hybrid integrated filtering capacitors on a large scale,in which a unit consists of rGO/MXene composite film as a negative electrode and PEDOT:PSS based film as a positive electrode.Benefiting from the synergistic effect of rGO and MXene components,and morphological characteristics of PEDOT:PSS,the capacitor unit exhibits outstanding AC line filtering with a large areal specific energy density of 1,015 μF V^(2)cm^(-2)(0.28 μW h cm^(-2)) at 120 Hz.After rational integration,the assembled capacitors present compact/lightweight configuration and lossless frequency response,as reflected by almost constant resistor-capacitor time constant of 0.2 ms and dissipation factor of 15% at120 Hz,identical to those of the single capacitor unit.Apart from standing alone steadily on a flower,a small volume(only 8.1 cm^(3)) of the integrated capacitor with 70 units connected in series achieves hundred-volts alternating current line filtering,which is superior to most reported filtering capacitors with sandwich configuration.This study provides insight into the fabrication and application of compact/ultralight filtering capacitors with lossless frequency response,and a wide range of operating voltage.展开更多
In order to study and popularize clones from the introduced Robinia pseudoacacia, morphological charac- teristics and leaf nutrition of samples of a three-year-old stand were observed and analyzed during its growing s...In order to study and popularize clones from the introduced Robinia pseudoacacia, morphological charac- teristics and leaf nutrition of samples of a three-year-old stand were observed and analyzed during its growing season. Combined with data on rooting ability, height and basal diameter, comparisons were made on morphological characteris- tics, growth traits and leaf nutrition of 11 introduced R. pseudoacacia clones （two from Hungary and nine from South Ko- rea） and two domestic clones, The results show that there are significant differences in growth and morphological char- acteristics among the 13 clones, but no significant differences in the contents of crude protein and crude fibers in the leaves （p 〉 0.05）. Height and basal diameter growth of clones B and G were recorded as the fastest, while clone H1 was the slowest. Clone H2 had the largest leaflets, three times as large as other clones, while K4 had the heaviest dry weight per 100 leaflets because of its thick leaves. The 13 clones can be divided into four classes based on the number of leaf- lets per compound leaf, i.e., 1-3, 13-17, 15-23 and 21-25. There were significant differences in thorn size： H2, with the largest leaflets had the smallest thorns. While of course all clones produced roots, there were significant differences; clones 2N, K5 and B had many adventitious roots, while clones K3, K4 and H1 had few. Correlation between content of crude protein and （length x width of leaf） was positive （p 〈 0.05）, while correlations of the content of crude protein, with the number of leaflets per compound leaf, petiole length of compound leaf and thorn length were negative （p 〈 0.01）. Plant height and basal diameter were positively correlated with each other （p 〈 0.01） and negatively correlated with base width of thorns （p 〈 0.05）.展开更多
文摘Bark beetle species in natural stands of spruce, Picea crassifolia （Kom.） were investigated in Maixiu Forest Park, Qinghai Province, northwest China, during 2005 and 2007. Two pioneer Ips species, Ips nitidus Eggers and Ips shangrila Cognato and Sun were found. I. nitidus occurs naturally in northwest China. I. shangrila is a new species in the world. In the past, it was confused with I. mannsfeldi Wachtl in China. The damage of these two Ips species has been very severe in Maixiu and the morphological and bio-logical characteristics were studied. I. nitidus starts to fly in early May and prefers the mid to lower part of the host tree to colonize as its habitat. I. shangrila always infests from the top of the trunk, especially in branches larger than 3 cm in diameter in the crowns and sometimes even colonizes entire young trees. The two Ips species are the most destructive secondary bark beetles on P. crassifolia and always cause mortality of trees by their cooperation.
基金funded by RESCOLL French society and the Lebanese University。
文摘In the present work,the focus has been shifted to the relationship between the PANI morphology and the physicochemical properties,controlled by the amount of added ionic liquids,of the polymerization medium instead of focusing on the structure of the ionic liquids as used to be in the litterature.For that reason,PANI has been synthesized in different weight ratio of[Pyrr][PTS]/water following the standard experimental process.The addition of[Pyrr][PTS]into the polymerization medium controls the morphology of PANI without affecting its structure.Moreover,[Pyrr][PTS]promotes a viscous reaction system without the need of an external source.The viscosity of the polymerization system restricts the diffusion of species that leads to the predominance of the homogeneous nucleation mode during the course of polymerization and,thus,nanostructuring of PANI morphology.As for the ionic conductivity,it reflects the mobility of the ions of the polymerization medium and,thus,the way of its interference with the formed PANI that affects the arrangement and the shape of formed PANI fibers.This relationship between PANI morphology and the physicochemical properties,adjusted by adding ionic liquids,of the polymerization medium is prelaminar and promising.The effect of the ionic liquids on the viscosity as well as on the mobility of the polymerization medium have to be taken into consideration to choose the ionic liquids,which lead to the PANI with desired morphology.
基金This paper was supported by National Natural Science Foundation of China (Grant No. 39670607).
文摘The classification of seedlings is important to ensure the viability of seedlings after transplantation and is acknowledged as a key factor in forestation and environmental improvement. Based on numerous papers on automatic seedling classification (ASC), the seedling grading theory, traditional grading methods, the background and the proceeding of ASC techniques are described. The automation of the measurement of seedling morphological characteristics by photoelectric meters and computer vision is studied, and the automatic methods of the current grading systems are described respectively. And the further researches on ASC by computer vision are proposed.
基金supported by the NSFC(21805072,22075019,22035005)the National Key R&D Program of China(2017YFB1104300)。
文摘Filtering capacitor with compact configuration and a wide range of operating voltage has been attracting increasing attention for the smooth conversion of the electric signal in modern circuits.Lossless integration of capacitor units can be regarded as one of the efficient ways to achieve a wider voltage range,which has not yet been fully conquered due to the lack of rational designs of the electrode structure and integration technology.This study presents an alternatingly stacked assemble technology to conveniently fabricate compact aqueous hybrid integrated filtering capacitors on a large scale,in which a unit consists of rGO/MXene composite film as a negative electrode and PEDOT:PSS based film as a positive electrode.Benefiting from the synergistic effect of rGO and MXene components,and morphological characteristics of PEDOT:PSS,the capacitor unit exhibits outstanding AC line filtering with a large areal specific energy density of 1,015 μF V^(2)cm^(-2)(0.28 μW h cm^(-2)) at 120 Hz.After rational integration,the assembled capacitors present compact/lightweight configuration and lossless frequency response,as reflected by almost constant resistor-capacitor time constant of 0.2 ms and dissipation factor of 15% at120 Hz,identical to those of the single capacitor unit.Apart from standing alone steadily on a flower,a small volume(only 8.1 cm^(3)) of the integrated capacitor with 70 units connected in series achieves hundred-volts alternating current line filtering,which is superior to most reported filtering capacitors with sandwich configuration.This study provides insight into the fabrication and application of compact/ultralight filtering capacitors with lossless frequency response,and a wide range of operating voltage.
基金financially supported by the National Key Technology R&D Program (No. 2006BAD01A1601)the National High Technology Research and Development Program of China (863 Program, No. 2007AA100105)+1 种基金the Special Fund for Agro-scientific Research in the Public Interest (No. 200803034)the Key ResearchProgram of the State Forestry Administration of China (No. 2004-04)
文摘In order to study and popularize clones from the introduced Robinia pseudoacacia, morphological charac- teristics and leaf nutrition of samples of a three-year-old stand were observed and analyzed during its growing season. Combined with data on rooting ability, height and basal diameter, comparisons were made on morphological characteris- tics, growth traits and leaf nutrition of 11 introduced R. pseudoacacia clones （two from Hungary and nine from South Ko- rea） and two domestic clones, The results show that there are significant differences in growth and morphological char- acteristics among the 13 clones, but no significant differences in the contents of crude protein and crude fibers in the leaves （p 〉 0.05）. Height and basal diameter growth of clones B and G were recorded as the fastest, while clone H1 was the slowest. Clone H2 had the largest leaflets, three times as large as other clones, while K4 had the heaviest dry weight per 100 leaflets because of its thick leaves. The 13 clones can be divided into four classes based on the number of leaf- lets per compound leaf, i.e., 1-3, 13-17, 15-23 and 21-25. There were significant differences in thorn size： H2, with the largest leaflets had the smallest thorns. While of course all clones produced roots, there were significant differences; clones 2N, K5 and B had many adventitious roots, while clones K3, K4 and H1 had few. Correlation between content of crude protein and （length x width of leaf） was positive （p 〈 0.05）, while correlations of the content of crude protein, with the number of leaflets per compound leaf, petiole length of compound leaf and thorn length were negative （p 〈 0.01）. Plant height and basal diameter were positively correlated with each other （p 〈 0.01） and negatively correlated with base width of thorns （p 〈 0.05）.
