表面修饰Ag_2S纳米微粒的制备及其量子尺寸效应研究

采用同阳离子共沉淀法制备了DDP修饰的Ag2 S纳米微粒 ,其紫外—可见吸收光谱和荧光光谱表明DDP修饰的Ag2 S纳米微粒具有显著的量子尺寸效应 ,粒子尺寸分布较窄 ,粒子表面存在多种表面态能级。     

68例智力低下儿童发病原因与发铅含量关系探讨

对本院遗传优生门诊１９９４年以来确诊为６８例智力低下儿童进行了发铅测定。其中１２人发铅明显超过正常值,占总数的１７．６％。发铅增高的１２人中,有５人为神经系统病变,１人为射材矮小,另外６例无明显医学原因。本组病例显示,铅对儿童的神经系统损害较明显。讨论了防止胎儿和儿童受铅毒害的措施。     

Hybrids of oxoisoaporphine–tetrahydroisoquinoline: novel multi-target inhibitors of inflammation and amyloid-β aggregation in Alzheimer’s disease

Molecular Diversity - A series of 8- and 11-substituted hybrids of oxoisoaporphine–tetrahydroisoquinoline have been designed and synthesized. The new derivatives strongly suppressed NO and...     

A Multi-Scale Stiffness Fractal Model of Joint Interfaces

Russian Physics Journal - Stiffness characterization of mechanical interfaces is quite crucial for the analysis of several tribological behaviors. In the research of industrial robots, joints exist...     

Agarose template for the fabrication of macroporous metal oxide structures

Agarose gels have been applied as templates for the formation of macroporous metal oxide structures. The preparation of the agarose template is extremely simple, and with variation of the agarose content, control over morphology is demonstrated: The average pore size decreases from 180 to 55 nm and the surface area increases from 238 to 271 m2 g(-1) with increasing agarose content in the gel. The gelling temperature was also found to influence the final template morphology. Conducting sol-gel chemistry within the template structure followed by removal of the template by heating to 450 degrees C gives porous inorganic oxides. The technique has been demonstrated for the oxides of titanium, zirconium, niobium, and tin. The final morphology of the metal oxide is homogeneous and results from a coating of the agarose structure. The pore diameter decreased and the specific surface area of the titanium dioxide materials increased from 28 to 66 m2 g(-1) as the agarose content in the template is increased from 0.5 to 5.0 wt%. The overall pore size and surface area are lower than the original gel due to shrinkage occurring with the sol-gel process, as well as crystallization and a loss of microporosity in the final material.     

A high-frequency EPR characterization of the S = 2 linear tri-atomic chain in Cr3(dpa)4Cl2·CH2Cl2

We report the high frequency electron paramagnetic resonance (HF-EPR) study of Cr₃(dpa)₄Cl₂, a linear tri-atomic (Cr^II)₃ chain, that was reported to be EPR silent at the X-band (9.5 GHz). Higher frequencies yield well resolved spectra for this S = 2 system even at room temperature. At 30 K, our variable frequency (34-400 GHz) EPR spectra yield a large axial zero-field splitting (D) of −1.643(1) cm⁻¹ as well as a small rhombic ZFS parameter E = 0.0339(4) cm⁻¹; with g_x = 1.9978(4), g_y = 1.9972(4), and g_z = 1.9808(4). The magnetic susceptibility measurements fully support the earlier magnetic susceptibility studies and the current EPR results. The observation of the EPR spectrum of only the S = 2 state at room temperature suggests that the ground state is well isolated from the excited states.     

通量修正法在日地空间MHD激波模拟中的应用

回顾了应用于日地空间磁流体力学模拟的多种数值方法．将通量修正（ＦＣＴ）法应用于一维球对称超音速太阳风和激波对的模拟，所得结果在物理上与文献相比符合很好．但得到的激波间断面比文献更精确，间断面网格点数在２～３个之间．此方法可推广到在多维情形下进行扰动的数值模拟．     

聚乙二醇与镉(Ⅱ)离子的配位作用及其对硫化镉结晶的影响

本文用电导法、红外光谱法、X射线衍射分析、热分析等方法研究了高分子量聚乙二醇与镉离子的相互作用 ,并对其相互作用机理进行了初步探讨。采用水溶性高分子模仿生物矿化合成了硫化镉晶体 ,对其结构进行了研究。     

PS-TiO2 复合纳米微球的表征及摩擦学行为

采用化学法合成了PS-TiO2复合纳米微球,并对其进行了TEM、 FTIR、 TGA及DSC等分析表征。将这种微球用作润滑油添加剂,在四球试验机上研究了它的减摩抗磨性能,同时又对磨斑表面进行了X射线光电子能谱分析(XPS).研究表明：这种添加剂有良好的抗磨性能,并能在摩擦表面形成由TiO2、 Fe2O3以及有机碎片所组成的边界润滑膜。     

甲烷氧化偶联W-Mn催化剂的制备及表征

本文详细报道了制备因素对Na-W-Mn—O/SiO_2催化剂反应性能的影响,并用O_2-TPD,XRD,FT-IR,LRS等方法对催化剂进行了表征。结果表明,该催化剂的最佳组成是Mn 0.32wt％—Na_2WO_4 4wt％/SiO_2,由混浆法制备的催化剂具有较好的稳定性,连续反应30 h后,其甲烷转化活性和C_2烃收率均保持不变。催化剂的结构研究表明,Na_2WO_4与SiO_2发生了相互作用,形成有Si参与的表面钨氧物种,该催化剂具有较好的催化活性与表面钨氧物种的形成相关联,Mn的加入,可能大大提高了该催化剂中表面晶格氧的浓度,从而加快了CH_4的活化速度。