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酚醛树脂粘度特性对覆膜砂性能的影响 被引量:6
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作者 冀运东 李琳 《热加工工艺》 CSCD 北大核心 2007年第13期44-46,共3页
通过实验研究了酚醛树脂粘温特性以及混有固化剂树脂的粘度变化曲线对覆膜砂强度和抗脱壳性的影响。根据酚醛树脂的粘度特性定义了恒粘温度(45泊时温度)和最小粘度。确定了覆膜温度等于恒粘温度+40℃的控制原则。分析了软化点、最小粘... 通过实验研究了酚醛树脂粘温特性以及混有固化剂树脂的粘度变化曲线对覆膜砂强度和抗脱壳性的影响。根据酚醛树脂的粘度特性定义了恒粘温度(45泊时温度)和最小粘度。确定了覆膜温度等于恒粘温度+40℃的控制原则。分析了软化点、最小粘度和强度的关系,指明了合成高软化点、高强度酚醛树脂的研究方向。分析了覆膜砂脱壳的原理以及根据粘度变化曲线判断树脂抗脱壳性的原理。 展开更多
关键词 酚醛树脂 粘度 覆膜温度 性能
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工艺参数对激光3D智能打印效果的分析研究
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作者 陈盛贵 四库 孙振忠 《激光杂志》 北大核心 2017年第12期79-82,共4页
为了摆脱激光3D智能打印中数据复杂、3D物体表面曲率不利于计算等情况,并从多个角度稳定提升激光3D智能打印效果,需从工艺参数入手进行分析与研究,因此,提出一种激光3D智能打印工艺参数分析方法,主要进行分层厚度与覆膜工艺参数对打印... 为了摆脱激光3D智能打印中数据复杂、3D物体表面曲率不利于计算等情况,并从多个角度稳定提升激光3D智能打印效果,需从工艺参数入手进行分析与研究,因此,提出一种激光3D智能打印工艺参数分析方法,主要进行分层厚度与覆膜工艺参数对打印效果的函数与实例分析。所提方法利用四叉树进行激光3D点云数据的处理与存储,通过切割四叉树来建立点云数据重心与分层厚度的关系图例,从四叉树切割误差入手进行最佳分层厚度的迭代求解。方法还讨论了覆膜工艺参数以及激光功率、3D扫描速率等对打印效果的影响,并给出各项工艺参数的最佳取值范围。实验结果表明,在所提方法给定的工艺参数支持下,激光3D智能打印工作的复杂度小、产品活化能高,具备很好的打印效果。 展开更多
关键词 工艺参数 激光3D智能打印效果 分层厚度 混砂时间 覆膜温度
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Effects of Different Plastic films Mulching on Soil Temperature and Moisture, the Growth and Yield of Sugarcane 被引量:3
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作者 许树宁 吴建明 +5 位作者 黄杏 谢金兰 罗亚伟 梁阗 黄家雍 李杨瑞 《Agricultural Science & Technology》 CAS 2015年第9期2073-2076,F0003,共5页
[Objective] The effects of different plastic films mulching on soil temperature and moisture, and growth and yield of sugarcane were discussed in order to provide references for using different plastic film in sugarca... [Objective] The effects of different plastic films mulching on soil temperature and moisture, and growth and yield of sugarcane were discussed in order to provide references for using different plastic film in sugarcane pro-duction. [Method]Four kinds of plastic films viz., normal colorless transparent plastic film, milky photodegradation weeding plastic film, black plastic film and gray-black plastic film were used in sugarcane cultivation by using no film mulching as the control. Soil temperature and moisture were measured during plastic film mulching period, and sugarcane agronomic traits such as emergence rate, tillering rate, plant hight, stalk diameter and effective stalk number were investigated during growth period, the cane yield and economic benefits were calculated during harvest period. [Result] The results showed that plastic film mulching could significantly increase soil temperature and moisture. Com-pared with the control, soil temperature was increased by 0.3-0.8 ℃ in three plastic films mulching treatment except for gray-black plastic film mulching. The soil moisture of all mulching treatments was 10.1%-17.4% higher than the control. Furthermore, the seedling emergence rate, tillering rate, effective stalk number and cane yield also could be improved using plastic film mulching,which were increased by 0.8%-9.9%, 20.6%-34.9%, 5190-10980 stalks/hm^2and6.4%-14.9% as compared to the control,while plant height and stalk diameter were found to be no significant effect by plastic film mulching. The results of benefit analysis indicated that, milky photodegradation weeding film mulching had the highest economic benefit, the second were normal colorless transparent plastic film mulching and black plastic film mulching, which were 5 987.2, 1 876.5 and 1 813.5 Yuan/hm^2 higher than the control. The gray-black film mulching treatment had poor benefit.[Conclusion] The milky photodegradation weeding plastic film could be vigorously extended in sugarcane production. Normal colorless transparent plastic film and black plastic film could be ex-tended gradually as a new kind of plastic film. The grayblack film should not be used for its higher cost and more thickness. 展开更多
关键词 Plastic film mulching Soil temperature Soil moisture SUGARCANE YIELD Economic benefit
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