New amidines from intramolecular cyclization in triflic acid of nitroketene aminals with a tethered phenyl ring

Nitroketene aminals with a tethered phenyl group underwent an intramolecular cyclization in trifluoromethanesulfonic acid to afford the corresponding N-(3-ethyl-hydrohydroxyiminobenzocyclo-alkenylidene)methylamine trifluoromethanesulfonate. The yields were fair to good excepted for the starting compound 1-[N-ethyl-N-(2-phenylethyl)amino]-1-methylamino-2-nitroethene.     

The mechanism of particle formation during homogeneous precipitation of zinc sulfide

Monodisperse zinc sulfide particles were prepared by homogeneous precipitation from zinc sulfate solutions. Particle size could be adjusted in the range of 1 to 5 microns by changing the viscosity of the reaction medium. From electron micrographs of particles prepared in high viscosity media subparticles up to 50 nm in diameter could be observed. From these results it was concluded that particle growth took place predominantly by Brownian coagulation.Furthermore, it was established that stirring the reactor content during the initial phase of particle formation alone did not influence particle size, nor did it promote coagulation of micron-sized spheres. We were able to prepare this material in amounts up to 2 kg of solid material from a reactor with a working volume of 36 l.     

同时测定重油中铁和锌的正三辛胺萃取-双波长K系数分光光度法

用正三辛胺萃取分离干扰离子，以Ｆｅ２＋（Ｚｎ２＋）－５＿Ｂｒ＿ＰＡＤＡＰ（２－（５－溴－２－吡啶偶氮）－５－二乙基氨基苯酚）－ＴｒｉｔｏｎＸ＿１００为显色体系，建立了双波长Ｋ系数法同时测定重油中微量铁、锌的新方法。考查了测定条件及萃取分离条件。线性范围：铁０～４８０μｇ／Ｌ、锌０～４００μｇ／Ｌ，合成样回收率（１００±２）％，重油测定结果的相对标准偏差小于５％。方法简便、准确。     

The 30° rotation domains in wurtzite ZnO films

The 30° rotation domains in ZnO films were studied by transmission electron microscopy (TEM) and high-resolution electron microscopy (HREM). The cross-section and plane-view observations reveal that the 30° rotation domains have elliptical cylindrical shape, with the longitude axis along one of the 1 1 2¯ 0 directions and the short axis along one of the 1¯ 1 0 0 orientations, respectively. The volume fraction of the 30° rotation domains is about 1%. Due to the elliptical shape of the domain boundaries along the [0 0 0 1]_ZnO direction, partially disordered superlattice-like structures are formed. As shown by the HREM images and Zn elemental mapping, these super-lattices are most likely caused by periodical segregation and depletion of Zn along the domain boundary for compensating the mismatched lattice strain.     

原子吸收法测定人精子中锌和铜含量的研究

本文采用石墨炉原子吸收法，以ＮＨ４ＮＯ３和Ｍｇ（ＮＯ３）２混合剂作基体改进剂，测定了人精子中微量元素铜和锌。基方法的特征质量分别为１０．００ｐｇＣｕ／０．００４４Ａ．Ｓ．，９．８０ＰｇＺ／０．００４Ａ．Ｓ；平均加收率为９７．４２％，锌为１０１．９１％，铜和锌的精密度分别是４．１％和４．０３％。     

2-(N-三氟乙酰-N-三甲基硅烷基)氨基-3-三甲基硅烷氧基-羧酸三甲基硅烷酯和2-(N-三氟乙酰)-2,3-脱氢氨基酸的合成

近十几年来,N原子上带有保护基团的α,β脱氢氨基酸及其衍生物的新的合成方法,由于发现这类化合物存在于微生物、低等植物和海生动物体中而具有重要意义。另     

胚胎发育与孕妇血锌含量的对比观察

为探讨早孕时期胚胎发育与微量元素的关系，测定了１２０例胚胎停止发育孕妇血锌含量，并与对照组比较，结果表明，８２例血锌含量低于对照组，占６８．３３％。     

大白鼠食饵性高锌实验

为了探讨过量锌对健康的影响，用葡萄糖酸锌作为添加剂对大白鼠进行了长期饲喂的实验研究，试验采用对照法，喂养时间３３周，结果表明，长期大量补锌会引起血清锌值明显升高，对消化系统会造成一定的损害。     

激光诱导荧光光度法测定食品中的锌

本文利用自行组装的激光诱导荧光 CCD阵列检测器 计算机联用装置 ,建立了一种测定食品中锌的灵敏方法。在乙酸 乙酸铵 ( pH =4 )缓冲溶液中 ,Zn(Ⅱ )与SCN、罗丹明B(RhB)反应生成Zn SCN RhB配合物 ,经乙醚萃取后 ,以YAG激光二倍频 5 32nm为激发波长 ,在 5 80nm处测定荧光强度 ,优化了反应及食品样品的处理条件 ,用于食品试样中锌的测定 ,获得了满意的结果 ,方法检出限 4ng/mL ,加标回收率90 0～ 1 1 0 0 % ,相对标准偏差为 2 0～ 9 7%。