Abstract: Organic multiple quantum well(OMQ) structures consisting of alternating layers of tris(8 - quinolinolato)aluminum( ff) (Alq3) and 2 - (4 - biphenylyl) -5 - (4 - ter - butylphenyl) -(1,3,3- oxadiazole) (PBD) ...Abstract: Organic multiple quantum well(OMQ) structures consisting of alternating layers of tris(8 - quinolinolato)aluminum( ff) (Alq3) and 2 - (4 - biphenylyl) -5 - (4 - ter - butylphenyl) -(1,3,3- oxadiazole) (PBD) have been fabricated by organic molecular beam deposition (OMBD). The individual layer thickness in the multilayer samples was varied from 6 nm to 20 nm. The multiple quantum well structures were determined by low angle X - ray diffraction, optical absorption and photolumi-nescence(PL). The PL spectra narrow and the emission energy has been observed to shift to higher energy compared with that in the monolayer structure, suggesting a quantum size effect.展开更多
Morphological changes of tubulin during the resumption of meiosis in both mouse oocyte and fertilized egg were revealed by indirect immunofluorescent marking with monoclonal antibody against β tubulin. During germin...Morphological changes of tubulin during the resumption of meiosis in both mouse oocyte and fertilized egg were revealed by indirect immunofluorescent marking with monoclonal antibody against β tubulin. During germinal vesicle period (GV), tubulin was found to be distributed around the GV menibrane. With the disruption of GV membrane, microtubule complexes (MTCs) appeared in cytoplasm, first around GV membrane later to spread to other portions as well. Quantitative difference was noted among different oocytes. MTCs coexisted with spindlesformed by prometaphase tubulin, while metaphase tubulin polymerized into spindles and anaphase and telophase tubulin was concentrated in the two poles of the meiotic apparatus and the midbody. In egg arrested in the 2nd metaphase, whether maturing in vitro or vivo, all the tubulin went to form spindles with no MTCs left in the cytoplasm. After fertilization in vitro,MTCs reappeared in the egg cytoplasm activated by sperms while no MTCs could be revealed in cytoplasm after formation of pronucleus. As demonstrated by this experiment,cytoplasmic tubulin in eggs are polymerized chiefly into two forms: the star-shaped MTCs and the spindle.Cytoplasmic MTCs are the structure newly formed when the 1st and 2nd oocytes resumed meiosis. With colchicine disrupting the polymerization of tubulin, the maternal chromosomes,instead of orderly arrangement and orderly separation, either formed disordered mass or were divided into multiple chromatin masses. However, the penetration of sperm into egg, and decondensation and formation of pronuclei were not affected.展开更多
An ATM ring switching testbed is proposed in this paper. Two practical applications for the ATMring exchange are aimed, one is used ai ATM LAM/MAN, another is for rural local ATM exchange. A dis-tributed swithching an...An ATM ring switching testbed is proposed in this paper. Two practical applications for the ATMring exchange are aimed, one is used ai ATM LAM/MAN, another is for rural local ATM exchange. A dis-tributed swithching and control architecture is designed. together with a modular and flexible hardware and soft-ware structure which permits a rapid and easy introduction and testing of new, services. Hierarchical VP and VCswitching is organized, three AALs (AAL1, AAL4 & AAL5) are supported to provide conaretion-oriented andconnectionless services Broadcasting, multicasting and multi-conferencing functions are achieved at no extra cost,and imerworking with the existing network is emphasized. The constucticon of ring access node is described. As anexample a PDH-ATM interface is given.展开更多
文摘Abstract: Organic multiple quantum well(OMQ) structures consisting of alternating layers of tris(8 - quinolinolato)aluminum( ff) (Alq3) and 2 - (4 - biphenylyl) -5 - (4 - ter - butylphenyl) -(1,3,3- oxadiazole) (PBD) have been fabricated by organic molecular beam deposition (OMBD). The individual layer thickness in the multilayer samples was varied from 6 nm to 20 nm. The multiple quantum well structures were determined by low angle X - ray diffraction, optical absorption and photolumi-nescence(PL). The PL spectra narrow and the emission energy has been observed to shift to higher energy compared with that in the monolayer structure, suggesting a quantum size effect.
文摘Morphological changes of tubulin during the resumption of meiosis in both mouse oocyte and fertilized egg were revealed by indirect immunofluorescent marking with monoclonal antibody against β tubulin. During germinal vesicle period (GV), tubulin was found to be distributed around the GV menibrane. With the disruption of GV membrane, microtubule complexes (MTCs) appeared in cytoplasm, first around GV membrane later to spread to other portions as well. Quantitative difference was noted among different oocytes. MTCs coexisted with spindlesformed by prometaphase tubulin, while metaphase tubulin polymerized into spindles and anaphase and telophase tubulin was concentrated in the two poles of the meiotic apparatus and the midbody. In egg arrested in the 2nd metaphase, whether maturing in vitro or vivo, all the tubulin went to form spindles with no MTCs left in the cytoplasm. After fertilization in vitro,MTCs reappeared in the egg cytoplasm activated by sperms while no MTCs could be revealed in cytoplasm after formation of pronucleus. As demonstrated by this experiment,cytoplasmic tubulin in eggs are polymerized chiefly into two forms: the star-shaped MTCs and the spindle.Cytoplasmic MTCs are the structure newly formed when the 1st and 2nd oocytes resumed meiosis. With colchicine disrupting the polymerization of tubulin, the maternal chromosomes,instead of orderly arrangement and orderly separation, either formed disordered mass or were divided into multiple chromatin masses. However, the penetration of sperm into egg, and decondensation and formation of pronuclei were not affected.
文摘An ATM ring switching testbed is proposed in this paper. Two practical applications for the ATMring exchange are aimed, one is used ai ATM LAM/MAN, another is for rural local ATM exchange. A dis-tributed swithching and control architecture is designed. together with a modular and flexible hardware and soft-ware structure which permits a rapid and easy introduction and testing of new, services. Hierarchical VP and VCswitching is organized, three AALs (AAL1, AAL4 & AAL5) are supported to provide conaretion-oriented andconnectionless services Broadcasting, multicasting and multi-conferencing functions are achieved at no extra cost,and imerworking with the existing network is emphasized. The constucticon of ring access node is described. As anexample a PDH-ATM interface is given.
