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81.
为解决新疆吐鲁番地区甜瓜工厂化育苗当中遇到的容易出现徒长苗,不易培育出适龄壮苗等问题,选用甜瓜品种"西州密十七号"为试材,研究不同浓度植物生长延缓剂多效唑(PP333)和比久(B9)浸种处理对甜瓜幼苗质量的影响。结果表明:甜瓜幼苗发芽势随着PP333溶液浓度的增大而降低,幼苗的株高和下胚轴长显著小于对照;浓度为60mg/L的PP333溶液浸种处理下的幼苗叶片厚度和幼苗壮苗指数最大;60mg/L和80mg/L的PP333溶液浸种处理下幼苗根冠比最大。PP333溶液浸种处理对甜瓜幼苗的株高、下胚轴长、叶片大小和厚度的抑制作用大于B9溶液,可以用于防止幼苗徒长,培育壮苗。 相似文献
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84.
旨在鉴别影响苏山猪初生体尺和乳头数性状的遗传位点,开发可用于辅助育种的分子标记,为苏山猪生长和繁殖性能的持续选育提供理论基础。本试验对269头苏山猪初生仔猪(出生后24 h内)的体尺和乳头数表型进行测定,并采集耳组织样品。基于全基因组重测序及基因型填充策略,利用全基因组关联分析(genome-wide association study, GWAS)和群体分化指数(fixation index,Fst)的方法挖掘与目的性状强关联位点,并对位置功能候选基因开展GO和KEGG分析,确定最有可能的主效基因。本研究共鉴别到4个候选位点,分布在13、14和X染色体上,其中与初生体尺性状显著关联的位点有2个,与乳头数性状显著关联的位点有2个。本研究筛选出1个与体长性状相关的候选基因ACTA2;1个与胸围性状相关的候选基因COL4A6;3个与乳头数性状相关的候选基因ACTA2、CRTAP和SEPTIN6,为苏山猪初生体尺性状和乳头数性状的遗传改良提供了重要的分子标记。 相似文献
85.
The application of lock-up clutch slip control balances the fuel economy and drivability, and greatly improves the performance of hydraulic automatic transmission. The structure of the lock-up clutch and the friction material of lock-up clutch lining are discussed, a detailed research on varying characteristic due to engaging time during the lock-up clutch engagement is developed, too. By applying the slip control, lower fuel consumption is achieved. 相似文献
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Jointing of titanium alloy and stainless steel is very often in the fields like aviation, chemical plants etc. The combination of materials has the advantages of both titanium alloy and stainless steel and will reduce the consumption of titanium resource. The phase transformation diffusion bonding of TA17 titanium alloy to 0CriSNigTi stainless steel are carried out on Gleeble - 1500D. The effcet of maximum thermal cycle temperature, the tensile strength, the fracture surface and microstruture of the joints are investigated. The results show that TiFe and TiFe2 intermetallics and some solid solutions are formed along the interface, when maximum thermal cycle temperature increase, the area proportion of intermetallics in the fracture surface increase, which are detrimental to the mechanical properties of the transition joints. 相似文献
88.
Control Strategy and Simulation Study on NiMH Battery Quick Charging for Regenerative Braking of HEV
Based on the result of NiMH battery performance experiments, changing trend of maximal temperature and difference in temperature of HEV NiMH battery in different SOC and different charging current is analyzed. Considering the working situation of HEV NiMH battery and the theory of battery quick charging, a control strategy for NiMH battery quick charging is described which adapts to HEV regenerative braking system based on Mascc law. By Modeling and simulating the process of NiMH battery quick charging with this strategy, constant voltage charge method and constant current charge method, validates this control strategy. 相似文献
89.
To the question that a meter is correspond with a set of lead and a sensor,this paper presents a design of data acquisition system for vehicle based on CAN bus.In this way,the combinatorial instrument is only connected by a bus unit.Author introduces the data acquisition structure chart and the CAN interface,analyzes the software by program flow chart,and shows it's application for vehicle virtual instrument.A method of calculating vehicle speed,engine rotate speed and the course of development mileage are also given. 相似文献
90.
Reference efficiency of a pair of gear drive without planetary motion is the base to calculate efficiency of the whole planetary gear train. The authors find reference efficiency for speed increase is higher than that of the same drive used for speed reduction. This is different from the earlier viewpoint. New equations are derived for correctly calculating the reference efficiency of spur gear and helical gear with internal conjugate and external conjugate either in the state of speed increase or speed reduction respectively. The equations are also used to calculate efficiency of 2K-H planetary gear train. 相似文献