分子束外延及溅射法制备Co/Cu多层膜结构与磁电阻的比较研究

对用分子束外延（MBE）和溅射方法制备的Co/Cu多层膜样品分别进行了结构及磁性研究．X射线分析表明两者均有良好的调制周期性，并且前者形成外延单晶结构，铁磁共振研究表明了面内六次各向异性对称的存在，说明此超晶格具有完整的面内二维结构．磁电阻测量发现，溅射制备的多层膜具有较高的磁电阻值并明显地随Cu层厚度而振荡，相应的室温磁电阻峰值分别为27%，24%，14%；而MBE制备的超晶格的磁电阻较小，其第二峰的数值只有7%．MBE超晶格界面处可能具有超顺磁性，对磁电阻和磁化强度的不同的外场依赖关系有一定的影响． 关键词：     

气体/表面活性剂水溶液两相流流型的断层测量

应用电导断层测量技术研究表面活性剂添加对水平管内气液两相流流型的影响,实验工质为空气/水、空气/100mg/kg十二烷基硫酸钠(SDS)水溶液。结果表明,表面活性剂的添加明显影响波状分层流向环状流型的转换;同时光滑分层流型也拓展到较高的气体流速范围;研究中没有观察到表面性剂对塞状流与弹状流转换的影响。     

tune调制对储存环横向稳定性影响的模拟研究

对包含非线性六极场储存环的线性tune(Qx,Qy)加以余弦调制,通过计算粒子轨道沿相角畸变的动力学孔径,研究了tune调制对储存环中粒子运动横向稳定性的影响.从模拟结果可以看出,tune调制对粒子稳定性的影响是一种长期效应.当调制振幅很小、调制tune远离共振岛tune值时,对粒子稳定性的影响很小,随着调制振幅增大,调制tune接近共振岛tune,影响越来越明显.     

980nm激光激发下Er3+和Yb3+共掺杂氟氧玻璃的上转换发光

制备了一种新型的上转换发光材料,它不仅具有较高的上转换发光效率,而且还避免了氟化物基质的缺点。其组分为58.52%PbF₂-34.43% GeO₂-3% Al₂O₃-0.05% Er₂O₃-4%Yb₂O₃,其中GeO₂为玻璃形成体氧化物,PbF₂和Al₂O₃为调整剂,以共掺杂Er³⁺和Yb³⁺离子为上转换研究的对象。测量了该玻璃系统在980nm半导体激光器激发下的上转换发光光谱,观察到很强的658nm的红光和548,526nm的绿光,而且红光的发射强度远远强于绿光。通过对上转换发光强度与激发强度关系曲线的拟合,表明此材料的绿光发射和红光发射都为双光子过程。研究了激发光的工作电流与上转换荧光强度的关系,讨论了其上转换发光特性。     

清洁及氧修饰Cu（100）表面上CO2加氢制甲醇反应的能量学

分别以清洁及氧悠Ｃｕ（１００）表面作为金属态铜和部分氧化态铜的表面模拟，用键级守恒－Ｍｏｒｅｓ势法研究了两种表面上ＣＯ２加氢制甲醇反应的能量学，计算结果表明，在两种表面上，ＣＯ２加氢制甲醇反应的优势反应途径均为“ＣＯ２，ｓ→ＨＣＯＯｓ→Ｈ２ＣＯｓ→ＣＨ３Ｏｓ→ＣＨ３ＯＨｓ”与清洁铜表面上的相应基元步骤相比，在Ｃｕ（１００）－ｐ（２×２）Ｏ表面上甲醇合成反应各基元步骤具有更低的活化能；ＨＣＯＯｓ是含     

N-取代-3-吲哚乙酰胺类α1-肾上腺素受体拮抗剂的设计、合成及其3D-QSAR研究

结合α1-受体拮抗剂的构效关系和我们应用计算机辅助药物设计方法所构建的药效团模型,设计合成了一系列N-取代-3-吲哚乙酰胺类化合物,并评价其α1-受体拮抗作用.初步生物活性测试表明,所合成的目标化合物多数具有较好的α1-受体拮抗活性.并应用SOMFA方法进行分子结构特征和α1-受体生物活性之间的关系研究.     

The further crystallographic refinement of trichosanthin at 2.7A resolution and the comparison among the three molecular structures in two crystal forms

The three-dimensional structure of trichosanthin at 2.7A resolution has been improved further, by refitting one of the C-terminal tails, adjusting 16 residues in the molecular surface regions, discarding some water molecules with high B values, and adjusting weights during the further refinement. The R-factor has been reduced to 18.5% and the r.m.s deviations from ideal geometry are also improved. The structures of the two molecules in the monoclinic asymmetric unit and the only molecule in the orthorhombic asymmetric unit are compared with one another. The main-chain structures for most of the residues in the three molecules are substantially the same. However, the courses of the three C-terminal tails are completely different, and the intermolecular interactions resulting from the particular packing of the molecules in the crystals account for the differences. The strand Be-2 and the preceding B-turn in small domain show large r.m.s. deviations among the three molecules and they are also involved in i     

纤维状硬脂酸银的合成及其表征

A new type of fibrous silver stearate (AgSt) was synthesized using double-jet method with KOH as pH regulator in water solution system. The structure, morphology and phase transiton behavior of the fibrous AgSt were characterized by FTIR, SEM, XRD and TG-DTA. SEM images showed that the diameter of the fibrous AgSt was about 150 nm and the length was 5～8 μm. XRD data indicated its layered structure and TG-DTA showed its high themal stability. In addition, the possible growth mechanism of the fibrous AgSt is also discussed.     

Synthesis of （S）-2-Ethoxy-3-Phenylpropanoic Acid Derivatives and Their Insulin-Sensitizing Activity

A series of （S）-2-ethoxy-3-phenylpropanoic acid derivatives were synthesized and their insulin-sensitizing activities were evaluated in 3T3-L1 cells. Compounds 1b, 1d, 1e and 1f exhibited more potent insulin-sensitizing activity than rosiglitazone.     

溴邻苯三酚红修饰碳糊电极吸附伏安法测定痕量锑

研制了溴邻苯三酚红(BPR)作修饰剂的碳糊修饰电极,并采用所制备的电极做工作电极建立了测定锑的方法。测定了电活性络合物的组成,并探讨了电极反应机理。该方法已用于锌电解液中痕量锑的测定,结果满意,检出限为2.0×10-8 mol/L。