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正防腐剂具有抑制微生物增殖和杀灭微生物的作用,被广泛应用于食品工业中。丙酸盐作为重要的食品防腐剂,对黄曲霉、好氧性芽孢杆菌、沙门氏菌及酵母菌均有较好的抑制作用,但是长期过量使用丙酸盐也会给消费者生命安全带来威胁。近年来丙酸盐的消费市场不断扩大,很多产品远销欧盟、美国、日本、韩国等国家。随着食品贸易发展,国外对食品中的丙酸盐制定了严格的限量要求~([1])。国家标准GB 2760-2014也对食品中丙酸盐的含量有严 相似文献
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采用磁控溅射技术在Si衬底上以350?C沉积14 nm的非晶Ge薄膜,通过退火改变系统生长热能,实现了低维Ge/Si点的生长.利用原子力显微镜(AFM)和拉曼(Raman)光谱所获得的形貌和声子振动信息,对Ge点的形成机理和演变规律进行了研究.实验结果表明:在675?C退火30 min后,非晶Ge薄膜转变为密度高达8.5×109cm-2的Ge点.通过Ostwald熟化理论、表面扩散模型和对激活能的计算,很好地解释了退火过程中,Ge原子在Si表面迁移、最终形成纳米点的行为.研究结果表明用高速沉积磁控溅射配合热退火制备Ge/Si纳米点的方法,可为自组织量子点生长实验提供一定的理论支撑. 相似文献
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Scaling dependence of memory windows and different carrier charging behaviors in Si nanocrystal nonvolatile memory devices 下载免费PDF全文
Based on the charge storage mode,it is important to investigate the scaling dependence of memory performance in silicon nanocrystal(Si-NC) nonvolatile memory(NVM) devices for its scaling down limit.In this work,we made eight kinds of test key cells with different gate widths and lengths by 0.13-μm node complementary metal oxide semiconductor(CMOS) technology.It is found that the memory windows of eight kinds of test key cells are almost the same of about1.64 V @ ±7 V/1 ms,which are independent of the gate area,but mainly determined by the average size(12 nm) and areal density(1.8×10~(11)/cm~2) of Si-NCs.The program/erase(P/E) speed characteristics are almost independent of gate widths and lengths.However,the erase speed is faster than the program speed of test key cells,which is due to the different charging behaviors between electrons and holes during the operation processes.Furthermore,the data retention characteristic is also independent of the gate area.Our findings are useful for further scaling down of Si-NC NVM devices to improve the performance and on-chip integration. 相似文献
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高效液相色谱法测定饲料中辛硫磷残留量 总被引:3,自引:0,他引:3
提出了高效液相色谱法测定饲料中辛硫磷残留量的方法。样品经乙酸乙酯提取,氨基固相萃取小柱净化,所得净化液以反相C18色谱柱为分离柱,以乙腈-水(65+35)混合溶液为流动相,在检测波长280nm处进行测定。辛硫磷的质量浓度与其峰面积在0.10~0.50mg·L-1范围内呈线性关系,方法的检出限(3S/N)为0.10mg·kg-1。加标回收率在80.0%~88.2%之间,测定值的相对标准偏差(n=5)在1.6%~6.5%之间。 相似文献
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