一种新型的卤化银颗粒尺寸和分布测定法-电解还原法及其测定仪

电解还原法是近年来国际上逐步使用的一种新的卤化银颗粒尺寸和分布测定的方法．用此方法，我们研制了我国第一台微机化的测量仪。这台仪器可以测量直径从0.1μm至40μm的所有各种卤化银颗粒，而且全部操作，包括信号的提取、识别、数字化转换以及数据处理都是自动进行。与过去常用的测量方法，如电镜图象分析法、离心沉降法以及激光散射法相比，此方法测量快速，测量精度高并且设备投资少，操作方便．此外，我们还对电解法与电镜法的测试结果作了比较。     

STUDIES ON POLY(ETHYLENE TEREPHTHA LATE)-POLY(TETRAMETHYLENE ETHER) MULTIBLOCK COPOLYMER.Ⅰ.COMPOSITIONAL HOMOGENEITY

The compositional homogeneity of a poly (ethylene terephthalate)-poly (tetramethylene ether) multiblock copolymer sample with low content of hard segment was examined by GPC, TLC, and solubility method. The copolymer sample was found to have a uniform composition as a function of elution volume over the major portion of sample from GPC method. However within one elution fraction, the copolymer chains, although having the same hydrodynamic volume, may have some difference in composition. Two fractions with different composition were obtained by precipitation in ethanol. Some low molar mass copolymers were also separated by a TLC technique from the copolymer sample.     

Gecko-inspired composite micro-pillars with both robust adhesion and enhanced dry self-cleaning property

Enhanced dry self surfaces were fabricated which could dislodge up to 24.6% of contaminated particles with as few as 4 steps.     

Tailoring 3D shapes of polyhedral milliparticles by adjusting orthogonal projection in a microfluidic channel

Polyhedral milliparticles (PMPs) have promising applications in self-assembly, tissue engineering, mechanical engineering, and photonics. The shapes and sizes of the PMPs have great impact on their functions. To date, the reported methods for adjusting the shapes and sizes of PMPs are still limited. Especially, it remains a challenge to fabricate the PMPs with high asymmetry. Here, we present a facile and efficient approach that focuses on the alteration of the relative positions between the microchannel and the UV light to tailor the shaping process of the PMPs. By tuning the rotation angle and translation displacement, a variety of monodisperse PMPs with both centrosymmetric and noncentrosymmetrical structures are synthesized, including tetrahedra, pentahedra, hexahedra, and so forth. Moreover, the polymeric PMPs are loaded with silica nanoparticles and further sintered into silica. The obtained silica PMPs hold great potential for the applications such as machining tools, abrasives, and electronics.     

Central elements in pseudoeffect algebras

We introduce the definition of pseudoorthoalgebras and discuss some relationships between orthomodular lattices and pseudoorthoalgebras. Then we study the conditions that a pseudoeffect algebra is isomorphic to an “internal direct product” of ideals generated by orthogonal principal elements. At last, we give some characterizations of central elements in pseudoeffect algebras.     

精密光束偏离装置棱镜组件的光机热分析

以精密光束偏离装置的棱镜组件为有限元模型,进行了光机热集成分析.对棱镜组件的结构强度进行了校核,分析了机械载荷作用下的镜面变形;通过模态分析,给出了装置的动态特性和镜面面形振动幅值的变化情况;最后对棱镜的热弹性变形进行了分析,对棱镜的光学性能进行了评价.结果表明：棱镜组件的最大变形在10 nm量级,最大应力为0.403 MPa,应力和应变相对于结构的准确度要求和材料的许用应力具有较大的裕度;前后棱镜组件的固有频率都大于550 Hz,装置具有良好的动态性能;通过对比棱镜在热-结构耦合分析和机械载荷下的分析结果,说明热效应对棱镜表面变形的影响远远大于机械载荷的影响.装置使用时必须采取严格的温控措施.     

锶Sr,钡Ba和镭Ra的单光子电四极矩光谱跃迁的理论研究

用带有Ｂｒｅｉｔ和ＱＥＤ修正的全相对论多组态Ｄｉｒａｃ－Ｆｃｃｋ平均能级（ＭＣＤＦ－ＡＬ）模型,计算了碱土金属Ｓｒ、钡Ｂａ和镭Ｒａ的单光子电四极矩＾１Ｄ－＾１Ｓ跃迁的光谱能量间隔,最大跃迁几率和振子强度。计算中考虑了重要的相对论效应、电子关联效应和核的有限体积效应,所得的结果与国外早期发表的结果进行了比较,此外还首次从理论上预言了镭Ｒａ的单光子电四极矩＾１Ｄ－１Ｓ光谱跃迁。     

咪唑啉硼酸酯的制备及摩擦学性能

以脂肪酸、β 羟乙基乙二胺、硼酸按不同比例分别合成了四种脂肪酸咪唑啉硼酸单酯和三酯。经ＩＲ、１ＨＮＭＲ和元素分析证明结构正确。用四球试验机评价了两种化合物在水中的摩擦学性能。结果表明这些化合物在水中具有良好的承载能力和抗磨性能,并初步探讨了这些化合物的抗磨作用机理     

儿童乙型肝炎疫苗免疫成功率监测结果分析

通过对广东医学院第二附属医院辖区海滨管区2003-01-01至2005-12-31出生的儿童559人免疫后检测其乙肝病毒表面抗体(抗-HBs),了解乙型肝炎疫苗(HepB)免疫成功率。结果表明,免疫成功率为84.26%,比2002年广东省调查儿童免疫后抗-HBs阳转率(62.18%)明显提高。提示HepB有较好的免疫效果,因此提高新生儿的HepB全程接种率和HepB第1针及时接种率,是控制乙肝的关键。