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51.
以2种不同结构的弹性体乙烯-辛烯共聚物接枝甲基丙烯酸缩水甘油酯(POE-g-GMA)和乙烯-丙烯酯甲酯-甲基丙烯酯缩水甘油酯三元共聚物(E-MA-GMA)增韧聚乳酸(PLA), 研究了接枝型与嵌段型弹性体的结构对聚乳酸增韧效果的影响. 结果表明, 接枝型聚合物POE-g-GMA与基体PLA之间具有良好的界面相互作用, 当POE-g-GMA的质量分数为15%时, 共混体系的缺口冲击强度为72.4 kJ/m2, 而E-MA-GMA的质量分数为15%时, 共混体系的缺口冲击强度为32.4 kJ/m2, 结果表明, 接枝型聚合物POE-g-GMA增韧效果明显优于嵌段型E-MA-GMA. 相似文献
52.
利用柚皮苷合成新橙皮苷二氢查尔酮工艺产生的副产物对羟基苯甲醛为原料,通过溴代、乙基化、甲基化、酸性水解反应合成异香兰素。该工艺具有成本低,污染少,资源循环利用特点,并且可通过中试放大应用于工业化规模生产。 更多还原 相似文献
53.
The KH 2 PO 4 crystal is a key component in optical systems of inertial confinement fusion (ICF).The microwaviness on a KH 2 PO 4 crystal surface is strongly related to its damage threshold which is a key parameter for application.To study the laser induced damage mechanism caused by microwaviness,in this paper the near-field modulation properties of microwaviness to the incident wave are discussed by the Fourier modal method.Research results indicate that the microwaviness on the machined surface will distort the incident wave and thus lead to non-uniform distribution of the light intensity inside the crystal;in a common range of microwaviness amplitude,the light intensity modulation degree increases about 0.03 whenever the microwaviness amplitude increases 10 nm;1 order diffraction efficiencies are the key factors responsible for light intensity modulation inside the crystal;the light intensity modulation is just around the microwaviness in the form of an evanescent wave,not inside the crystal when the microwaviness period is below 0.712 μm;light intensity modulation degree has two extreme points in microwaviness periods of 1.064 μm and 1.6 μm,remains unchanged between periods of 3 μm and 150 μm,and descends above the period of 150 μm to 920 μm. 相似文献
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55.
The magnetization of ternary metal Prussian blue analogues A1xA21-x B,formed by three different sublattices A1,A2 and B,is studied by using the effective-field theory with self-spin correlations.Effects of the mole fraction x,the anisotropy and the transverse magnetic field on the magnetization are discussed. 相似文献
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碳酸钙粒子增韧高密度聚乙烯的脆韧转变-Wu氏增韧理论聚合物共混物脆韧转变判据的适用条件 总被引:2,自引:0,他引:2
采用不同尺寸的碳酸钙粒子增韧高密度聚乙烯,研究了不同温度下共混体系的临界粒子间距与碳酸钙粒子尺寸和含量之间的关系,确定了温度是Wu氏增韧理论临界粒子间判据适用性的重要影响因素。 结果表明,在17 ℃下,临界粒子间距与碳酸钙粒子的尺寸和含量无关,该条件下Wu氏增韧理论临界粒子间距判据是适用的;而随着温度的升高,发现临界粒子间距依赖于碳酸钙粒子的尺寸,表明高温条件下,Wu氏增韧理论临界粒子间距判据不再适用。 相似文献
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59.
通过同轴圆筒剪切仪和磁子搅拌方式提供的剪切流场,研究了均匀和非均匀流场对ABA两亲性三嵌段共聚物囊泡的影响.研究发现,非均匀流场下囊泡尺寸及其分散度随剪切速率的增加呈现先增大后减小的规律.与搅拌形成的非均匀流场相比,在同轴剪切仪提供的均匀流场下形成的囊泡尺寸更加均匀.结果表明,剪切流场是影响囊泡形貌的重要因素,流场的不均匀性是导致组装体形貌结构多分散性的重要原因之一. 相似文献
60.
Lattice stabilities,mechanical and thermodynamic properties of Al_3Tm and Al_3Lu intermetallics under high pressure from first-principles calculations 下载免费PDF全文
The effects of high pressure on lattice stability, mechanical and thermodynamic properties of L1_2 structure Al_3Tm and Al_3Lu are studied by first-principles calculations within the VASP code. The phonon dispersion curves and density of phonon states are calculated by using the PHONONPY code. Our results agree well with the available experimental and theoretical values. The vibrational properties indicate that Al_3Tm and A_3Lu keep their dynamical stabilities in L1_2 structure up to 100 GPa. The elastic properties and Debye temperatures for Al_3Tm and Al_3 Lu increase with the increase of pressure. The mechanical anisotropic properties are discussed by using anisotropic indices AG, AU, AZ, and the threedimensional(3D) curved surface of Young's modulus. The calculated results show that Al_3Tm and Al_3Lu are both isotropic at 0 GPa and anisotropic under high pressure. In the present work, the sound velocities in different directions for Al_3Tm and Al_3Lu are also predicted under high pressure. We also calculate the thermodynamic properties and provide the relationships between thermal parameters and temperature/pressure. These results can provide theoretical support for further experimental work and industrial applications. 相似文献