6元素集合上T0拓扑总数的计算

文中证明了有限预序集与有限偏序集的一些性质,并基于有限集上的拓扑和其上预序的一一对应关系,利用这些性质通过对极小元和极大元个数进行分类讨论,以一种有别于计算机算法而又容易理解的计算方法得出6元素集合上的T₀拓扑总数为130023.     

Equivariant Chern Classes of Orientable Toric Origami Manifolds∗

A toric origami manifold, introduced by Cannas da Silva, Guillemin and Pires, is a generalization of a toric symplectic manifold. For a toric symplectic manifold, its equivariant Chern classes can be described in terms of the corresponding Delzant polytope and the stabilization of its tangent bundle splits as a direct sum of complex line bundles. But in general a toric origami manifold is not simply connected, so the algebraic topology of a toric origami manifold is more difficult than a toric symplectic manifold. In this paper they give an explicit formula of the equivariant Chern classes of an oriented toric origami manifold in terms of the corresponding origami template. Furthermore, they prove the stabilization of the tangent bundle of an oriented toric origami manifold also splits as a direct sum of complex line bundles.     

基于统一灰色生成算子的三参数离散灰色预测模型及其应用

现有三参数离散灰色预测模型的累加阶数取值范围局限于正实数,导致模型建模能力和作用空间受限。为此,论文首先引入实数域统一灰色生成算子;然后,基于统一灰色生成算子构造了新型三参数离散灰色预测模型,实现了其阶数从正实数到全体实数的拓展与优化,从而使得新型模型具备挖掘时序数据积分特性与差异信息的双重功能;最后,将该新模型应用于某装甲装备维修经费的建模,结果显示其精度优于其它同类灰色模型。本研究成果对完善灰色算子基础理论及提高灰色预测模型建模能力具有重要价值。     

三元合金Cu76Ni15Sn9的离子溅射研究

在２７ｋｅＶ Ａｒ⁺离子轰击时,用收集膜技术结合俄歇谱仪（ＡＥＳ）,研究了三元合金Cu₇₆Ni₁₅Sn₉系统的择优溅射行为。同时使用扫描电子显微镜（ＳＥＭ）与电子探针微分析（ＥＰＭＡ）．观察了靶点表面形貌变化并测定了形貌特征微区的合金组份原子的相对百分浓度。结果表明,Ｃｕ原子较Ｎｉ原子、Ｎｉ原子较Ｓｎ原子,在所测定范围（０─６０°）内择优发射。最后讨论了靶点表面形貌特征和“元素局域富集”现象对择优溅射过程的影响。 关键词：     

基于国产仪器研究钨丝原子吸收光谱

用标准的150 W幻灯灯泡的钨丝作原子化加热材料,设计制作了一种新颖的、结构简单的钨丝电热原子化器,同时还设计了该原子化器的电源电路和信号的数据采集电路.该原子化器能的最高原子化温度可达3100 K左右;编写了硬件的控制软件和信号处理的应用软件.用该原子化器将实验室一台火焰原子吸收光谱仪改装成钨丝原子吸收光谱仪,并以铜元素标准溶液和PerkinElmer公司多元素标准溶液对仪器性能作了研究.仪器对铜的检出限为0.0133 μg/mL,线性范围为0.10～4.0 μg/mL;对1.0 μg/mL的铜标准溶液测试的相对标准偏差为RSD=4.1%(测试次数n=10),每次分析所需样品量20 μL.     

Effect of Co-solvent on the Palladium Catalyzed Alkoxycarbonylation of Allyl Bromide in Supercritical CO_2

We have studied the palladium-catalyzed alkoxycarbonylation of allyl bromide in supercritical (sc) CO2 and found the reaction rate in sc CO2 was lower than those in some organic solvents1. The possible reason was the lower solubility of sc CO2 for the palladium catalyst. As an effective approach to improve the solubility of varieties of solutes, cosolvent such as ethanol has been widely used in the sc CO2 extraction2,3. Based on the above consideration, we chose several organic reagents…     

Dioxygen Affinities and Catalytic Oxidation Performance of Cobalt (II)Complexes with N-Aryl Hydroxamic Acid

It is well known that the study on biomimetic oxygen carriers not only has important theoretic significance to discover the mechanism of reversible bonding, activating oxygen as well as the oxidation reaction in organism, but also has potential application in separating oxygen from air and realizing the high efficiency and selectivity of catalytic oxidation reaction under a mild condition1. Metal- porphyrin and metal- phthalol- gaunine have been extensively used as biomimetic oxygen carriers u…     

RAMAN STUDIES OF STRUCTURAL PHASE TRANSITION IN[n-C_(11)H_(28)NH_8]_2ZnCl_4

The perovskite type of compound [n-C_(11)H_(23)N_3]_2ZnCl_4(abr.C_(11)Zn)exhibits two solid-solid phasetransitions at T_(c1)=298.7 K and T_(c2)=360.1 K.A temperature dependence study of Raman spectra of C_(11)Znprovides the evidence of occurence of the structural phase transition related to the dynamics of thealkylammonium ions.The room temperature phase is ordered and contains the all-trans alkyl chains.Theintermediate temperature phase presents a partial conformational disorder and liquidlike state of allconformational disorder occurs at high-temperature phase.     

电热蒸发进样—等离子体原子发射光谱中钒和钛的蒸发机理研究

自1974年Nixon报道钽丝电热蒸发作为ICP-AES进样技术以来,这一技术已引起了人们的极大兴趣,受到越来越广泛的重视。电热蒸发(ETV)-ICP-AES是一种将蒸发和激发分步进行的联用技术。石墨是目前普遍使用的蒸发器材料。然而,在高温下某些元素和石墨材料可以发生碳化反应,形成热稳定的碳化物,使分析物蒸发不完全或根本不蒸发,从而影响分析结果的灵敏度和准确性。为了解决这一问题,我们曾提出了以聚四氟乙烯(PTFE)悬浮体为氟化剂,氟化辅助ETV-ICP-AES直接测定粉煤标样中钒和钛的新方法,其检出限     

化学反应动力学研究法──自函数回归法及其应用

由完全非线性函数经变换得到自函数递推方程．根据回归分析理论，建立了一种化学反应动力学研究法──自函数回归法．应用该法在25℃水溶液中研究了乙酸乙酯和了酸乙酯的皂化反应的动力学常数．