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1.
orphology of eleven pear cultivars planted in Yanbian state was observed with the scanning electron microscope(SEM).The results showed that there was no pollcn in Yanbian daxiangshui、Yanbianxiaoxiangshui、Mingyueli、Shanli.The Common traits of other seven cultiv ars were overlength sphere Oprelate spheroid shape.There were 3-colporate,striped sculptillc and bores on surface.The st 相似文献
2.
737ng的反推故障对飞行性能和飞行安全都有一定程度的影响,在航线的维护中,如处理不当,往往还会影响航班的准点.所以,了解反推系统的原理和掌握一定的故障排除技能就显得尤为重要.本文主要介绍一些反推系统的原理和一些典型故障的排除方法. 相似文献