排序方式: 共有64条查询结果,搜索用时 15 毫秒
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nmSiO2对聚合物光纤光栅封装材料的改性研究 总被引:3,自引:1,他引:2
分析了刚性纳米粒子改性聚合物的原理,重点分析了nmSiO2/硅氧烷(硅橡胶)复合材料的改性机理,采用120号溶剂性汽油为分散剂,通过共混法制得nmSiO2—乙烯基硅氧烷、含氢硅氧烷硫化而成的复合材料,用AJ-Ⅲa型原子力显微镜分析研究了该材料的组团结构并测试了其力学性能,结果表明,硅氧烷橡胶改性后,材料的弹性模量增加了15.4%;拉伸强度增加了19.4%;扯断伸长率增加了30%,用改性后的硅氧烷聚合物材料封装光纤Bragg光栅(FBG)压力传感器,可有效改善封装材料与光纤光栅的耦联性能;通过粒子含量控制可以增韧增强硅氧烷,从而可制作变量程压力传感器,同时可以延长传感器的使用寿命, 相似文献
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简易液体折射计的制作与使用李兰(四川江油市第一中学校621700)在高中物理"折射率"一节的教学中,要测定光从空气进入玻璃的折射率只需用光具盘等现成仪器便可测量.然而要测定液体的折射率,个别学校有的也是旧式仪器,操作既不方便效果又不好,只能演示光进入... 相似文献
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Purine nucleoside phosphorylase is a key enzyme in the purine-salvage pathway and an attractive target for drug design. The crystal structure of Streptococcus mutants purine nucleoside phosphorylase(Smu PNP) has been solved by molecular replacement at 1.80 resolution and refined to R factors of 19.9%/23.7%(Rcryst/Rfree) . Sequence alignment and structural comparison show that Smu PNP has more similarity with PNPs isolated from human and malarial sources than the bacterial PNPs. The structure complexed with hypoxanthine(HPA) and sulfate ion was solved at 2.24 resolution and refined to R factors of 21.6%/24.1%(Rcryst/Rfree) . It is interesting to note that the resulting electron density indicated the product,HPA,presents in the active site although inosine was included in the crystallization mixture with Smu PNP. Asn233 and Glu191 are the important residues for ligand binding and recognition. Comparison with PNPs from different species gives detailed information about binding of small molecules on the active site,which is important for the studies of enzymatic mechanism and rational design of specific inhibitors for PNPs. 相似文献
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电化学免疫法测定鸡肉组织中青霉素 总被引:8,自引:1,他引:7
将玻碳电极(GCE)表面氧化处理后,用戊二醛(GA)作交联剂,将新亚甲蓝(NMB)及辣根过氧化酶(HRP)标记的青霉素多克隆抗体(Ab*)修饰到电极表面,制成高灵敏电流型青霉素免疫传感器. 通过循环伏安法考察了电极表面的电化学特性,并对鸡肉中青霉素的残留进行了定量的研究. 结果表明,传感器对鸡肉中含有的青霉素检测的线性范围是5~45 ng/g,相关系数为0.974 7,最低检出限为1.90 ng/g. 考察了蛋白沉淀剂的沉淀效果,发现运用饱和硫酸铵对鸡肉中蛋白和脂类的沉淀效果最好. 样品回收率最高为74.5%. 干扰性实验表明,交叉干扰和鸡肉中其它成分干扰均较小. 修饰的电极稳定性较好,可用于实际肉样中青霉素含量的测定. 相似文献