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on the influence of the sintering temperature. A polymorphic phase transition (PPT) from orthorhombic to tetragonal symmetry was observed when the sintering temperature was raised from 1040 to 1050......
(X-ray powder diffractometer) at different heat treatment temperatures. The results show that amorphous barium titanate powder can transfer into tetragonal symmetry structure after heat treatment......
temperature field, simultaneously, the symmetry of the average residence time and the fluid flow pattern has improved, and the fluid flow in the tundish has been more reasonable. In case of a symmetric......
with the mechanical quality factor decreasing from 228 to 192. A phase transition from tetragonal to orthorhombic symmetry was identified by XRD analysis, and the corresponding calculation of lattice parameters......
高效液相色谱法测定水产品中7种兽药残留量孟勇1,张美琴1,王静2,谭秀慧2,吴光红1,21. 农业部渔业产品质量监督检验测试中心2. 江苏省水产质量检测中心摘 要:提出了高效液相色谱法同时测定水产品中呋喃唑酮,噁喹酸,萘啶酸及4种磺胺类药物等7种兽药残留量的方法.样品经乙腈提取,正己烷脱脂,用中性氧化铝柱和C18固相萃取柱进行分离及净化.以Symmetry C18色谱柱为分离柱,以不同体积比混合的乙腈与0.08mol.L-1乙酸溶液为流动相进行梯度洗脱,紫外检测器于波长265nm处检测.7种兽药的质量浓度与其峰面积均在0.05~1.0mg.L-1范围内呈线性关系,检出限(3S/N)为0.01~0.04mg.kg-1.方法的回收率在68.2%~97.3%之间,相对标准偏差(n=6)在1.6%~14%之间......
固相萃取-高效液相色谱法同时测定饮料中植物生长调节剂和杀菌剂残留量张旭1,王国琴2,余晓峰3,王丽丽1,潘再法11. 浙江工业大学化学工程与材料学院2. 杭州职业技术学院杭州市绿色精细化工研究与技术转化重点实验室3. 浙江省化工研究院化工产品检测中心摘 要:提出了高效液相色谱法同时测定饮料中2种植物生长调节剂(多菌灵,6-苄基腺嘌呤)和2种杀菌剂(多效唑,腈菌唑)含量.样品滤液过GDX501固相萃取小柱,经水-甲醇(80+20)混合溶液淋洗后,用甲醇洗脱.洗脱液在Waters Symmetry C18色谱柱上进行分离,流动相为甲醇与pH 6的5mmol.L-1磷酸盐缓冲溶液(67+33)混合液.4种化合物的线性范围均为1.0~50mg.L-1,检出限(3S/N)分别为......
反相离子对高效液相色谱-电感耦合等离子体质谱法测定富硒酵母中硒高愈希1,蒲云霞1,2,彭晓敏1,吴刚21. 中国科学院高能物理研究所核分析技术重点实验室2. 包头医学院基础医学部摘 要:富硒酵母样品用pH 7.5的Tris-盐酸缓冲溶液经超声破碎提取30min,于提取液中加链霉蛋白酶E在37℃搅拌18h,高速离心分离.取上清液经Millipore Corp超滤膜过滤,滤液中无机硒(Ⅵ及Ⅳ)和有机硒,即硒代半胱氨酸,硒代尿素和硒代蛋氨酸通过Waters Symmetry ShieldRP18色谱柱分离.用不同比例混合的甲醇-七氟丁酸溶液作流动相进行梯度洗脱,用电感耦合等离子体质谱法在线测定洗脱液中各种形态硒的含量.5种形态硒的质量浓度均在100μg·L-1以内呈线性.应用此法分析了富硒酵母样品,结果表明......
基质固相分散-高效液相色谱法测定袋泡茶中黄曲霉毒素徐飞1,高贵桃1,钱鑫21. 宁夏回族自治区疾病预防控制中心理化科2. 广东省佛山市药品检验所摘 要:提出了基质固相分散-高效液相色谱法测定袋泡茶中黄曲霉毒素B1,B2,G1和G2含量的方法.优化的试验条件为:1样品与分散剂(中性氧化铝)的质量比为1比4;2洗脱剂乙腈的用量为6mL.以Symmetry C18色谱柱为分离柱,以甲醇-水(1+1)混合液为流动相进行分离.采用荧光检测,激发波长为365nm,发射波长为435nm.黄曲霉毒素B1,B2,G1和G2在一定的质量浓度范围内与其峰面积呈线性关系,方法的检出限(3S/N)在0.050.15μg·L-1之间,测定下限(10S/N)在0.150.50μg·L-1之间.以空白样品为基体进行加标回收试验,所得......
equations. By constructing a three-dimensional anisotropy model with the cubic CA cells, simulation of dendritic growth of magnesium alloy with six-fold symmetry in the basal plane was achieved......
twinning states that the net atomic displacements are divided into shear and shuffles during twinning.Based on the theory and the hypothesis of full mirror reflection symmetry,the displacement and angle......