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红皮云杉的扦插繁殖技术 被引量:27
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作者 赵丽惠 张兴祥 +3 位作者 彭冬梅 文华 李森友 杨文化 《东北林业大学学报》 CAS CSCD 北大核心 1997年第1期15-18,共4页
在全光自控喷雾条件下,对不同年龄的红皮云杉硬枝和嫩枝进行了扦插繁殖,试验结果表明:在扦插繁殖中存在着明显的年龄效应和位置效应,来自于小年龄母株,树冠中下部的插穗具有较高的生根能力;用硝酸盐稀土100μg/g浸泡插穗3... 在全光自控喷雾条件下,对不同年龄的红皮云杉硬枝和嫩枝进行了扦插繁殖,试验结果表明:在扦插繁殖中存在着明显的年龄效应和位置效应,来自于小年龄母株,树冠中下部的插穗具有较高的生根能力;用硝酸盐稀土100μg/g浸泡插穗3h可使7年生嫩枝插穗生根率达88.72%,高出对照31.9%;扦插苗移栽的最佳时间为8月中旬。 展开更多
关键词 红皮云杉 年龄效应 位置效应 扦插繁殖 生根率
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变温载荷下某陶瓷/不锈钢结构连接性能分析与结构优化
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作者 邓飞 陈辉 文华 《机械》 2013年第6期30-34,共5页
Al2O3陶瓷/不锈钢连接结构因其兼具陶瓷和金属的性能优势,在结构工程领域得到了广泛的应用,但由于陶瓷、不锈钢及其连接材料的热物理性质不匹配,在零件存储、使用过程中,环境温度变化会导致连接处产生较大的热应力和热变形,削弱各层材... Al2O3陶瓷/不锈钢连接结构因其兼具陶瓷和金属的性能优势,在结构工程领域得到了广泛的应用,但由于陶瓷、不锈钢及其连接材料的热物理性质不匹配,在零件存储、使用过程中,环境温度变化会导致连接处产生较大的热应力和热变形,削弱各层材料间的连接性能。基于大型通用有限元计算软件ANSYS,针对某Al2O3陶瓷/不锈钢/Kovar合金连接结构,建立了有限元分析模型,分析得出了变温载荷下该结构整体及联接处的应力应变规律,并在此基础上对该结构进行优化。 展开更多
关键词 变温载荷 热应力 热变形 结构优化
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真空包套锻造成形有限元模拟及试验
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作者 周朝辉 蒲治军 +1 位作者 文华 江学强 《热加工工艺》 CSCD 北大核心 2011年第13期72-73,共2页
采用有限元模拟技术,分析了包套锻造的成形过程,用以指导包套结构设计及工艺参数制定,并进行了对比试验,得到了与模拟较为一致的结果。
关键词 真空包套锻造 有限元模拟 对比试验
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Electron beam braze-welding of vanadium alloy to stainless steel with electroplated Cu/Ag coatings 被引量:1
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作者 Wang Yarong Teng Wenhua Yu Yang 《China Welding》 EI CAS 2016年第3期9-15,共7页
Cracks may easily occur in the fusion weld between vanadium alloys and stainless steel due to the brittle intermetallics and welding stress. The high vacuum electron beam braze-welding has been successfully used to jo... Cracks may easily occur in the fusion weld between vanadium alloys and stainless steel due to the brittle intermetallics and welding stress. The high vacuum electron beam braze-welding has been successfully used to join vanadium alloy(V-5Cr-STi) to stainless steel (HR-2) with electroplated Cu and Ag coating. To investigate the effects of electroplated coating on the weldability, the joint appearaace, the microstrueture and the mechanical properties of the joints have been thoroughly analyzed. The results show that the joint surface configuration was good and root reinforcement was full and smooth. A reaction zone (RZ) was gained on the interface between the V-5 Cr-5 Ti alloy and HR-2 stainless steel base metals. The width of reaction zone at the top of the joint was up to O. 65 mm, wider than that in the bottom of the joint ( 0.46 mm). The reaction zone consisted of considerably smaller dendritic structures with an average grain size of less than 10μm. Element Ag and Cu almost enriched the interface between V-SCr-5Ti alloy substrate and RZ, serving as a physical barrier which decreases or avoids the formation of intermetallics. The maximum tensile strength of vanadium alloy^stainless steel dissimilar alloy joint was more than 300 MPa. The joint was defects free. 展开更多
关键词 electron beam braze-welding vanadium alloy stainless steel electroplate
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Effect of welding parameters on Al/Ti joint property in electron beam welding-brazing 被引量:8
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作者 Wang Yarong Yu Yang Teng Wenhua 《China Welding》 EI CAS 2016年第4期27-33,共7页
The electron beam welding-brazing being used to join 5A06 Al alloy to TC4 Ti alloy decreases the formation of brittle intermetallic compound.Experiments were carried out to study the influence of electron beam welding... The electron beam welding-brazing being used to join 5A06 Al alloy to TC4 Ti alloy decreases the formation of brittle intermetallic compound.Experiments were carried out to study the influence of electron beam welding parameters on the tensile strength of welds,based on an orthogonal test and analysis method.The welding parameters include beam current,welding speed,scanning figure,scanning frequency,figure size,beam offset and focus current.The optimum parameters for3 mm 5A06 Al alloy and 2 mm TC4 alloy were as follows:acceleration voltage was 60 kV,beam current was 11 mA,welding speed was 600 mm/min,focus current was 0 mA,scan figure was O,scanning frequency was 1 000 Hz and beam offset was 0.5 mm.The results show that the joints were with good appearance and quality welded by the optimum parameters.The successful joints could be gained and the maximum tensile strength of Al/Ti dissimilar alloy joints could be up to 222.61 MPa using electron beam welding-brazing. 展开更多
关键词 Al alloy Ti alloy electron beam welding-brazing orthogonal test and analysis
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