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Introduction Intheposttreatmentofchoppedfibreproduction,the thirddraftingrollerandtensionheat settingrolleroftenwere tangledbybrokentowforthereasonofhighspeed,hightemperatureofrollersurface,orotheradditionalforeign factors.While,thetworollerswerekeysegmentinthewhole technology.Itwouldleadtooneormoredrumcavedin,and eventobediscardediftheequipmenthadnotbeenstoppedintime.Usually,suchaccidentwouldbringgreatloss,what wouldnotbegotback.Sothetotalsetofequipmentrequiredthatdetectormusthavegoodperfo… 相似文献
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本文对计算机辅助鉴定技术在海洋浮游植物分类鉴定中的应用进行了探讨,总结了不同技术的特点,并在总结计算机辅助鉴定技术在海洋浮游植物分类鉴定方面应用现状的基础上,对其发展前景做出了展望。 相似文献
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Kanamaru S Leiman PG Kostyuchenko VA Chipman PR Mesyanzhinov VV Arisaka F Rossmann MG 《Nature》2002,415(6871):553-557
Bacteriophage T4 has a very efficient mechanism for infecting cells. The key component of this process is the baseplate, located at the end of the phage tail, which regulates the interaction of the tail fibres and the DNA ejection machine. A complex of gene product (gp) 5 (63K) and gp27 (44K), the central part of the baseplate, is required to penetrate the outer cell membrane of Escherichia coli and to disrupt the intermembrane peptidoglycan layer, promoting subsequent entry of phage DNA into the host. We present here a crystal structure of the (gp5-gp27)3 321K complex, determined to 2.9 A resolution and fitted into a cryo-electron microscopy map at 17 A resolution of the baseplate-tail tube assembly. The carboxy-terminal domain of gp5 is a triple-stranded beta-helix that forms an equilateral triangular prism, which acts as a membrane-puncturing needle. The middle lysozyme domain of gp5, situated on the periphery of the prism, serves to digest the peptidoglycan layer. The amino-terminal, antiparallel beta-barrel domain of gp5 is inserted into a cylinder formed by three gp27 monomers, which may serve as a channel for DNA ejection. 相似文献
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Résumé Des expériences sur l'inhibition de l'implantation normale de l'oeuf fertilisé dans la paroi utérine (l'effetBruce), faites avec plusieurs générations de souris consanguines ainsi qu'avec un groupe hétérosanguin, indiquent que la disparition de cette inhibition est due à la sélection plutôt qu'à l'homozygosité. L'odeur provoquant cette inhibition et celle qui favorise la synchronisation estrogénique (l'effetWhitten), semblent être des émanations urinaires différentes.
This investigation was supported by research grants HD-01141 and HD-00767 from the National Institute of Child Health and Human Development. 相似文献
This investigation was supported by research grants HD-01141 and HD-00767 from the National Institute of Child Health and Human Development. 相似文献
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