溶液中金属元素的激光诱导击穿光谱

利用激光击穿光谱的方法对水溶液样品中的金属元素进行定性和定量分析。分别采用竖直喷流(口径0.5 mm)和静止液面两种样品采样模式,针对不同质量浓度的Cd,Fe,Al和Pb元素进行了检测分析并得到了其定标曲线(线性拟合相关度基本在0.99以上),初步确定了4种元素在喷流模式下的检测限为0.206 5(Cd),0.147 6(Fe),0.061 9(Al)和0.200 9(Pb)g/L;静止液面模式下的检测限为0.050 1(Cd),0.0239(Fe),0.014 8(Al)和0.006 9(Pb)g/L。实验所得的结果为检测工业废水中金属元素的含量提供了依据。     

Temperature dependence of the magnetic penetration depth in YBa2Cu3O6.95

We report precision transverse fieldSR measurements of the internal field distribution in the vortex state of crystalline YBa₂Cu₃O_6.95. A novel low background apparatus was used to study a mosaic sample of three high quality single crystals (T_c=93.3K). The observed frequency spectra in magnetic fields of 5kG and 15 kG applied along the c-axis have the characteristic features expected for a regular vortex lattice with some additional broadening. From a preliminary analysis we find that [(0)/(T)]² has a linear temperature coefficient forT<30 K. Such a term is inconsistent with simple s-wave pairing in the superconducting state. These results support recent microwave measurements of(T) on similar crystals in zero applied field but differ significantly from previousSR reports on sintered powders and crystals with lower T_c.This research was supported by the Natural Sciences and Engineering Research Council of Canada.     

Surface atomic imaging of La2CuO4 and superconducting Tl2Ba2Ca2Cu3O10

Surface structures of the high T_c oxide superconductors Tl₂Ba₂Ca₂Cu₃O₁₀ and La₂CuO₄ have been studied by high resolution electron microscopy. In addition to the single atomic layer of La on the (113) surface observed previously, several atomic layers of the C-form of La₂O₃ were found to coat the (001) surfaces of La₂CuO₄. Surface reconstruction with the incorporation of excess Ba on the (110) surface of Tl₂Ba₂Ca₂Cu₃O₁₀ has been observed together with a stepped (11l) surface produced by a combination of the (110) and (001) planes. The (001) surface of Tl₂Ba₂Ca₂Cu₃O₁₀ was also found to terminate with a Ba-O layer. Possible mechanisms for the formation of these surface structures are discussed.     

The deformation of the neutron-rich isotopes102Mo and104Mo

The half-lives of low-lying levels of the neutron-rich isotopes¹⁰²Mo and¹⁰⁴Mo have been measured at the fission product separator Josef with the ß-- triple coincidence technique. Values of t_1/2= 126(4)ps and 0.72(4)ns have been obtained for the 2₁ ⁺ levels at 296 keV and 192 keV in¹⁰²Mo and¹⁰⁴Mo, respectively. Deformation parameters of ß_q=0.28(1) and 0.31(1), respectively, are deduced, which are smaller than those of the isotones of Sr and Zr. The interacting boson model accounts well for the trend of 2⁺ energies in the Mo isotopes but slightly overpredicts the B(E2) values at saturation. A smooth dependence of 2₁ ⁺ vs. E 2₁ ⁺ is found for the A 100 region in agreement with the hydrodynamical model.Dedicated to Prof. Dr. P. Kienle on the occasion of his 60th birthday     

牙齿化石中由辐照产生的陷阱电子的热稳定性研究

本文对周口店北京猿人遗址的动物牙齿化石进行了辐照产生的陷阱捕获电子的热稳定性研究和釉质样品及牙质样品的热稳定性对比实验。得到釉质样品中g=2.0016 ESR峰的寿命为7.1×10⁶年(20℃)。说明了取该峰进行ESR年代测定的可信性和用釉质样品进行ESR年代测定的必要性。     

平面对称标量场的静态时空

本文求出零质量标量场产生的平面对称度规的静态通解,并研究了它的对称性、奇异性等整体特性,发现平面对称情况与球对称不同,标量场的引入与否,其时空的奇异性没有本质差别。 关键词：     

关于建立新型激励机制与综合应用激励手段的研究

本文从西方激励理论与我国企业现状出发．探索了建立适合改革中的企业管理体制的新型激励机制之路，指出新型激励机制中多种激励手段应有机地综合运用．首先对西方激励理论进行了分析．而后对“人”在管理中的地位进行了探讨．在分析我国激励机制中现存缺陷后．提出了从组织结构、企业文化、领导行为多个方面进行变革以建立新型激励机制的建议．     

关于物质激励与精神激励基础与结合研究

从激励的心理学理论基础出发进行分析；对需求、动机、行为等及其相互影响在激励实践中的作用进行了总结。精神激励和物质激励是两种主要的激励模式．它们都是从实践中来经过否定之否定而发展起来的．现代激励理论对两种激励基本上接受，但对两种激励的评价及侧重又各有不同．我国现行激励机制存在一些问题，尤以平均主义为甚．精神激励与物质激励的有机结合．是激励模式发展的未来．     

聚合反应制备键合型纤维素-三(4-甲基苯基甲酸酯)衍生物类手性固定相

合成了带有甲基丙烯酰基的纤维素-三(4-甲基苯基甲酸酯)衍生物(CTMB),并通过聚合反应将其键合在具有双键的硅胶表面,得到手性固定相(CSP)。用所得到的CSP对9种对映体化合物(丁苯酞、酮基布洛芬、反-2,3-二苯环氧乙烷、安息香、安息香类似物、托葛尔碱、华法令、4,4′-二甲氧基-5,6,5′,6′-二次甲二氧基-2,2′-羰甲基甲酯联苯、4,4′-二甲氧基-5,6,5′,6′-二次甲二氧基-2-羰甲基甲酯-2′-羰甲基乙酯联苯)进行了拆分。考察了CSP制备过程中甲基丙烯酰氯的用量、键合方式以及硅胶