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俞建勇, 张广平, 戴干策
塑料工业,2003,31(8):32~34,-0001,():
-1年11月30日
研究了玻纤毡增强热塑性复合材料(GMT)流动成型过程中模腔压力和材料流动方向对制品力学性能和纤维取向的影响。研究表明:随着压力提高,弯曲强度和模量同步增加;但压力超过18MPa后,性能变化不明显。随布料面积分数减小,单轴拉伸流动成型将导致沿流动方向和垂直流动方向强度及模量差异变大,纤维取向严重;但双轴拉伸流动成型得到的制品各方向性能较均匀,基本呈现各向同性。
玻纤毡增强热塑性复合材料, 流动成型, 纤维分布, 聚丙烯
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【期刊论文】Tangential Load Measurements by a Smart Textile Composite
俞建勇, BIN YANG AND JIANYONG Yu, XIAO MING TAO, AND Hoi LUI HO
Textile Res. J. 74 (9), 810-818 (2004),-0001,():
-1年11月30日
A cellular textile composite structure integrated with fiber Bragg grating (FBG) sensors is designed for tangential load distribution measurements. The composite consists of many cylindrical shell cells for which a unit cell is fabricated from polyester and glass woven fabrics and epoxy. FBG sensors are bonded on the surface of the cells. The feasibility of using this cellular composite to measure tangential load distribution is demonstrated by experiments. The strain induced wavelength shift in the FBG sensor has a linear relationship with the tangential force within a definite range. Numerical simulations are created by finite element analysis. The influences of the environmental temperature, thickness, and effective moduli of the composite and the influences of the position and direction of the FBG sensors are discussed. The sensitivities of Ibis device are 0.09nm/N (for PET tension), 0.05nm/N (for PET compression), 0.04nm/N (for glass tension), and 0.03nm/N (for glass compression), and the measurement ranges are 0-
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俞建勇, 张广平, 辛忠, 桂全德, 王善元
石油化工,2003,32(9):771~774,-0001,():
-1年11月30日
采用差示扫描量热计考察了2,2’-亚甲基-双(4,6一二叔丁基苯基)磷酸及其衍生物在聚丙烯中成核的有效性,并研究了成核剂对力学性能的影响。结果表明:在聚丙烯中添加0.4%(质量分数)的磷酸酯的钠盐或甘油酯,使聚丙烯的结晶温度提高了15℃或11℃,结晶度增加3%~6%,结晶速率显著增加;在反复熔融、结晶过程中,其成核效应没有发生改变;材料的模量提高了20%~30%,弯曲强度也提高了10%~20%。其它几种磷酸酯的成核效果不明显。
成核效应, 热稳定性, 结晶速率, 有机磷酸酯, 聚丙烯
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俞建勇, 张广平, 朱维平, 李发学, 戴干策
高分子材料科学与工程,2004,20(1):157~160,-0001,():
-1年11月30日
用DSC手段考察了反应釜内原位共聚制备的含有成核剂及纳米碳酸钙的聚丙烯(PP)共聚物的非等温结晶行为。结果表明,成核剂使PP共聚物的结晶温度升高,结晶度降低,结晶速率略有提高。而纳米碳酸钙则大幅提高了PP共聚物的结晶温度和结晶速率,结晶度也增加了约1O%。并采用Ozawa法和Caze法描述了非等温结晶动力学。
聚丙烯共聚物, 原位聚合, 成核剂, 纳米碳酸钙, 非等温结晶动力学
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【期刊论文】LETTER TO THE EDITOR An iteration formulation for normalized diode characteristics
俞建勇, Ji-Huan He , , *, †, Yu-Qin Wan and Qian Guo
Int. J. Circ. Theor. Appl. 2004; 32: 629-632,-0001,():
-1年11月30日
By a general Lagrange multiplier, an iteration approach is proposed to solve the generalized normalized diode equation, by suitable choice of the initial trial-function, one-step iteration leads to a high accurate solution, which is valid for the whole solution domain. Copyright
diode, modelling, Lagrange multiplier, iteration
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