排序方式: 共有35条查询结果,搜索用时 15 毫秒
31.
采用高压微波辅助提取法提取牛黄上清丸中的黄芩苷, 利用蜜丸的粘性, 将蜜丸涂敷在自制毛玻璃片表面后, 置于高压微波提取装置中进行提取, 同时与直接将蜜丸切块置于微波装置进行了对比. 相似文献
32.
33.
对食用盐中碘和盐业部门的加碘食盐 (根据调查加碘食盐中碘均以碘酸钾形式加入 )中的碘含量进行监测时 ,由于此项工作样本量多 ,为了避免人为误差 ,可运用Excel电子表格的数据处理功能 ,对测定的大量数据进行统计计算 ,提高其准确度。1 原理碘盐中的碘酸钾在酸性环境中 ,加入过量的碘化钾析出碘 ,以淀粉作指示剂 ,用硫代硫酸钠标准溶液滴定并计算其含量 :IO- 3+ 5I- + 6H+3I2 + 3H2 O 2Na2 S2 O3+I2 2NaI+Na2 S4 O62 食盐中碘含量检测称取碘盐 10 .0 0 0 0 g置于 2 5 0ml碘量瓶中 ,加无碘水 5 0ml使盐… 相似文献
34.
Growth of n-type ZnO thin films by using mixture gas of hydrogen and argon 总被引:1,自引:0,他引:1 下载免费PDF全文
High-quality oxide semiconductor ZnO thin films were prepared on
single-crystal sapphire and LaAlOZnO薄膜 氩氢混合气体 薄膜生长 异质结构 薄膜物理学 ZnO, PLD, heterostructure Project supported by the National Natural Science Foundation of China (Grant No 19974001) and the National Key Basic Research Special Foundation of China (Grant No NKBRSF G1999064604 and G2000036505). 2005-05-30 9/3/2005 12:00:00 AM High-quality oxide semiconductor ZnO thin films were prepared on single-crystal sapphire and baAlO3 substrates by pulsed laser deposition (PLD) in the mixture gas of hydrogen and argon. Low resistivity n-type ZnO thin films with smoother surface were achieved by deposition at 600℃ in 1Pa of the mixture gas. in addition, ferromagnetism was observed in Co-doped ZnO thin films and rectification Ⅰ - Ⅴ curves were found in p-GaN/n-ZnO and p-CdTe/n-ZnO heterostructure junctions. The results indicated that using mixture gas of hydrogen and argon in PLD technique was a flexible method for depositing high-quality n-type oxide semiconductor films, especially for the multilayer thin film devices. 相似文献
35.
利用固相反应法及溶胶凝胶法我们制备了多晶La1-xSrxCoO3(x=0.7,0.8,0.9,1.0)样品.X射线衍射谱表明,La1-xSrxCoO3样品呈ABO3型钙钛矿结构,晶格常数随着x的增加而增大.与钙钛矿结构的锰氧化物类似,电阻率随温度变化以及磁化强度随温度变化的关系强烈依赖于掺杂浓度.x=0.7和0.8的样品在低温下显示铁磁性,而x=0.9和1.0的样品磁化强度随温度变化没有显示铁磁转变.电阻率随温度的变化似乎与磁化率测量相对应,在x=0.8和0.9样品之间存在绝缘-金属转变. 相似文献