A novel hybrid process for surface fluorination of polymers is being introduced. The process is based on ultra violet (UV) laser radiation, which on the one hand forms radicals out of an atmosphere of a partially fluo...A novel hybrid process for surface fluorination of polymers is being introduced. The process is based on ultra violet (UV) laser radiation, which on the one hand forms radicals out of an atmosphere of a partially fluorinated benzene, and on the other hand activates a polymer surface in the areas where the UV radiation hits the surface. The radicals can react with the polymer surface, hence altering the surface energy. With this process, a fluorine content of over 30% on the surface of bulk polystyrene can be achieved, while the smallest possible structure size was smaller than 1 mm.展开更多
An analytical model describing the physical relations of a UV-based process for halogenation of polymeric surfaces is presented. The process allows, depending on the parameters, a local halogenation with sharp edges a...An analytical model describing the physical relations of a UV-based process for halogenation of polymeric surfaces is presented. The process allows, depending on the parameters, a local halogenation with sharp edges at the interfaces to areas where no halogenation is desired. This is achieved via a nonreactive halogen-containing gaseous precursor and a UV source providing photons which dissociate the precursor photolytically. Thus, only where the UV photons affect the precursor, halogens are generated and the polymer is being halogenated.展开更多
大田原位种植元阳梯田2个地方水稻品种——白脚老粳和月亮谷,研究2年不同强度（0、2.5、5.0和7.5 k J·m^-2）UV-B辐射对水稻穗下第1至第4节的茎秆性状（节间长、茎秆粗和茎壁厚）和倒伏指数的影响.结果表明：增强UV-B辐射对水稻茎...大田原位种植元阳梯田2个地方水稻品种——白脚老粳和月亮谷,研究2年不同强度（0、2.5、5.0和7.5 k J·m^-2）UV-B辐射对水稻穗下第1至第4节的茎秆性状（节间长、茎秆粗和茎壁厚）和倒伏指数的影响.结果表明：增强UV-B辐射对水稻茎秆的节间长和茎秆粗没有显著影响,但导致茎壁厚度显著减小,其中,7.5 k J·m^-2UV-B辐射对水稻穗下第4节茎秆茎壁厚度的影响较大,降幅为11.6%-19.6%;增强UV-B辐射导致水稻茎秆的倒伏指数增加,增大水稻倒伏的风险,水稻穗下第4节茎秆倒伏指数最大,并大于倒伏临界值（200）;水稻穗下第4节、第3节和第2节茎秆的倒伏指数与茎壁厚度呈显著负相关.表明增强UV-B辐射显著减小元阳梯田水稻茎秆的茎壁厚是增加其倒伏风险的主要原因.展开更多
In this paper, we define a class of strongly connected digraph, called the k-walk- regular digraph, study some properties of it, provide its some algebraic characterization and point out that the 0-walk-regular digrap...In this paper, we define a class of strongly connected digraph, called the k-walk- regular digraph, study some properties of it, provide its some algebraic characterization and point out that the 0-walk-regular digraph is the same as the walk-regular digraph discussed by Liu and Lin in 2010 and the D-walk-regular digraph is identical with the weakly distance-regular digraph defined by Comellas et al in 2004.展开更多
文摘A novel hybrid process for surface fluorination of polymers is being introduced. The process is based on ultra violet (UV) laser radiation, which on the one hand forms radicals out of an atmosphere of a partially fluorinated benzene, and on the other hand activates a polymer surface in the areas where the UV radiation hits the surface. The radicals can react with the polymer surface, hence altering the surface energy. With this process, a fluorine content of over 30% on the surface of bulk polystyrene can be achieved, while the smallest possible structure size was smaller than 1 mm.
文摘An analytical model describing the physical relations of a UV-based process for halogenation of polymeric surfaces is presented. The process allows, depending on the parameters, a local halogenation with sharp edges at the interfaces to areas where no halogenation is desired. This is achieved via a nonreactive halogen-containing gaseous precursor and a UV source providing photons which dissociate the precursor photolytically. Thus, only where the UV photons affect the precursor, halogens are generated and the polymer is being halogenated.
文摘大田原位种植元阳梯田2个地方水稻品种——白脚老粳和月亮谷,研究2年不同强度（0、2.5、5.0和7.5 k J·m^-2）UV-B辐射对水稻穗下第1至第4节的茎秆性状（节间长、茎秆粗和茎壁厚）和倒伏指数的影响.结果表明：增强UV-B辐射对水稻茎秆的节间长和茎秆粗没有显著影响,但导致茎壁厚度显著减小,其中,7.5 k J·m^-2UV-B辐射对水稻穗下第4节茎秆茎壁厚度的影响较大,降幅为11.6%-19.6%;增强UV-B辐射导致水稻茎秆的倒伏指数增加,增大水稻倒伏的风险,水稻穗下第4节茎秆倒伏指数最大,并大于倒伏临界值（200）;水稻穗下第4节、第3节和第2节茎秆的倒伏指数与茎壁厚度呈显著负相关.表明增强UV-B辐射显著减小元阳梯田水稻茎秆的茎壁厚是增加其倒伏风险的主要原因.
基金Supported by the National Natural Science Foundation of China (Grant Nos.1077105110971052)+2 种基金the National Natural Foundation of Hebei Province (Grant No.A2008000128)Educational Committee of Hebei Province(Grant No.2009134)Youth Science Foundation of Hebei Normal University (Grant No.L2008Q01)
文摘In this paper, we define a class of strongly connected digraph, called the k-walk- regular digraph, study some properties of it, provide its some algebraic characterization and point out that the 0-walk-regular digraph is the same as the walk-regular digraph discussed by Liu and Lin in 2010 and the D-walk-regular digraph is identical with the weakly distance-regular digraph defined by Comellas et al in 2004.
