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本文扼要介绍了“改进的”满应力设计方法(FSD)在机身结构设计中的应用.除了通常的应力约束和最小尺寸约束外,还包含构件屈曲约束.当考虑屈曲约束时,应用本文导出的“欠松弛”系数,有效地改善应力比再设计过程中的振荡现象.结构理想化模型中除杆、板和梁元外,还采取了某些“虚”元和标量元,以避免复杂机身结构理想化模型的“病态”问题.优化设计的计算机程序由一些模块构成,在发展时,易于修改与扩充.程序提供一些功能选择,包括对收敛后的设计作某些调整和进行最后的结构分析,使结果更为可靠.在某机身结构的实例应用中,设计经五次迭代,基本收敛.收敛的设计比初始经验设计轻11%,效果较好. 相似文献
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新有机试剂4—(2—苯并噻唑偶氮)焦Bei酚的合成,性能和分析应用 总被引:4,自引:0,他引:4
本文以2-氨基苯并噻唑为原料,经重氮化后与焦Bei酚偶联合成了4-(2-苯并噻唑偶氮)焦Bei酚,用乙醇重结晶精制。并用元素分析、波谱等鉴定了结构。测定了其离解常数和质子化常数。研究了该试剂的一般性质、多配位显色反应,发现其与Mo(Ⅵ)、W(Ⅵ)、Ti(Ⅵ)等的显色反应在CTMAB和CPB等阳离子表面活性剂存在下有高的灵敏度。 相似文献
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亚硫酸钠酸碱滴定法测定人造板及制品中甲醛释放量 总被引:2,自引:0,他引:2
随着室内装修的普及,近年来我国的甲醛污染日趋严重,用作室内装饰的各种人造板材及其制品、木家具等均含有甲醛成分并会逐渐向周围环境释放。甲醛是一种无色易溶的刺激性气体,可经吸入、食入、经皮吸收侵入人体。现代科学研究表明,甲醛对人们的身体健康构成很大的危害。因此,国家发布了多项标准对各类人造板材及其制品、木家具的甲醛释放量作了严格的限量规定。 相似文献
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通过测定循环伏安曲线研究了石墨-SbCl5在1MLiClO4-PC(碳酸丙二醇酯)溶液中的电化学行为.I.II级石墨-SbCl5的还原电流峰出现在2.75~2.35V,氧化电流峰在2.85~3.05V(相对于Li/Li[+]).III级和IV级的相应电位区间与上相同,但其峰值较小,且曲线较为平缓,III级石墨-SbCl5的方波恒电流充放电表明,在500μA/cm[2]下,Li的插入量x(x=Li/C36SbCl5)在0.3以内,电极具有良好的可逆性,根据库仑滴定数据,放电前后X射线衍射图谱与电镜衍射花样的变化,初步认为I.II混合级石墨-SbCl5放电时的阴极反应是锂插入和形成新的层间化合物LiC24SbCl5的两个过程。 相似文献
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Design of tunable wavelength microcavity organic electroluminescent diode with liquid crystal 总被引:2,自引:0,他引:2
A novel designed method for tunable wavelength microcavity organic electroluminescent diode (MOLED) based on the birefringence of liquid crystal was presented. By modulated the refractive index of liquid crystal, the device could radiate with different wavelength continuously. The simulated result showed that the tunable range could reach to 60 nm and the full width of half maximum is 5.5 nm. The device could be applied to wavelength converter and tunable light source. 相似文献
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新有机试剂BTASPAP水相光度法测定Fe(Ⅲ) 总被引:5,自引:0,他引:5
研究了新有机试剂2-(2-苯并噻唑偶氮)-5-磺丙氨基苯酚(简写BTASPAP)与Fe(Ⅲ)的水相显色反应。Fe(Ⅲ)在pH3.0~4.2范围内与BTASPAP形成组成比为1:3的稳定的,易溶于水而又带负电荷的蓝紫色配合物,其表观摩尔吸光系数ε580为4.0×10^4,Fe(Ⅲ)在0~40μg/25ml范围服从比耳定律,所拟方法用于纯铝和铝合金标样中铁的测定,结果满意。 相似文献
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Tissue factor(TF), the cell surface receptor and requisite cofactor for the inactive serine protease factor VⅡa(VⅡa), binds VⅡa and its zymogen factor VⅡ with picomolar affinity on the cell surface. The TF:VⅡa complex proteolytically converts downstream zymogen factors X and IX to their active protease states in the cascade responsible for thrombogenesis and hemostasis. The TF pathway also produces cellular signaling through protease activated receptors. Here we present a crystal structure of the completely intact surface domain of TF in complex with VⅡa that reveals a significant conformational difference as compared to free TF. A long loop of residue 78~91 of the tissue factor(named ? loop here) was found to have well-ordered conformation, whereas this loop in free TF has an expanded conformation and is largely disordered. This loop adopts a tight conformation consisting of five β turns in the TF:VⅡa complex. The ? loop is located at the interface of the proteins of the complex, has a few interactions with VⅡa, and is possible to accommodate the sequence variations of TF in different mammalian species. 相似文献