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41.
Observation of banded spherulites and lamellar structures by atomic force microscopy 总被引:1,自引:0,他引:1
Spherulites are common structures of semi-crystalline polymers. It has been known that semi-crystalline polymers can form spherulites when crystallized from solution or from melt. A dark Maltese cross of a spherulite could be easily observed under the polarized optical microscopy (POM). Moreover, some spherulites show an additional alternating dark and bright concentric ring structure that is attributed to the regular twisting of the radial crystallite ribbons as they grow from the spherulit… 相似文献
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丁明珍彭璟马少玲姜勇秦文璟 《理化检验(化学分册)》2018,(10):1172-1176
向5mL水样中加入0.1g NaCl,溶解后加入50μL三氯甲烷(萃取剂)和300μL丙酮(分散剂),以4 000r·min-1的转速离心2min。采用气相色谱-质谱法测定所得有机相中5种芳香胺的含量,以内标法定量。结果表明:5种芳香胺的质量浓度在一定范围内与其峰面积与内标的峰面积的比值呈线性关系,检出限(3S/N)为0.000 1~0.001 5mg·L-1。以实际空白水样为基体进行加标回收试验,回收率为94.7%~106%,测定值的相对标准偏差(n=6)均小于5.0%。 相似文献
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以小鼠为实验对象对表达鲑鱼降钙素的转基因酵母进行了毒理学实验,包括急性毒性实验、遗传毒性实验(小鼠骨髓微核实验、小鼠精子畸形实验)、传统致畸实验和大鼠30 d喂养实验.结果表明,急性毒性实验显示LD50>10.0 g/kg,属于实际无毒物质;遗传毒性实验结果均为阴性,显示无致突变性;致畸实验结果表明转鲑鱼降钙素基因酵母对小鼠不会产生母体毒性,对小鼠胚胎发育无影响且无致畸作用;30 d喂养实验中各项检测指标均无显著差异(p>0.05),组织病理切片检查未发现病理性变化.本文的结论是口服转鲑鱼降钙素基因酵母未对实验动物造成不良影响,是安全无毒的. 相似文献
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Effect of growth temperature on morphology, structure and luminescence of Tb-doped BN thin films 下载免费PDF全文
This paper investigates the effect of growth temperature on
morphology, structure and photoluminescence (PL) of Tb-doped boron
nitride (BN) films grown by magnetron sputtering, and the
relationships of growth-temperature-structure-PL by scanning
electron microscopy, transmission electron microscopy and PL. The
characteristic emission lines of the Tb3+ were observed in the
PL spectra at room temperature. The 473-K-grown film is mainly
consisted of amorphous BN particles. With the growth temperature
increasing up to 1273 K, the amount of amorphous BN decreases,
while the amount of turbostratic BN increases. Correspondingly, the
PL intensities from the Tb3+ ions increase with the increase of
temperature in the range of 473--1273 K. 相似文献
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Microstructures and magnetic properties of Ta/Pt/Co 2 FeAl(CFA)/MgO multilayers are studied to understand perpendicular magnetic anisotropy(PMA) of half-metallic full-Heusler alloy films.PMA is realized in a 2.5-nm CFA film with B2-ordered structure observed by a high resolution transmission electron microscope.It is demonstrated that a high quality interface between the ferromagnetic layer and oxide layer is not essential for PMA.The conversions between in-plane anisotropy and PMA are investigated to study the dependence of magnetic moment on temperature.At the intersection points,the decreasing slope of the saturation magnetization(M s) changes because of the conversions.The dependence of M s on the annealing temperature and MgO thickness is also studied. 相似文献
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First-principles calculations based on density functional theory are performed to study the origin of ferromagnetism in boron-doped ZnO. It is found that boron atoms tend to reside at Zn sites. The induced Zn vacancy is a key factor for ferromagnetism in Zn1-xBxO (0相似文献