湿消解-电感耦合等离子体发射光谱法测定药用胶囊中的铬含量

以硝酸作为消解液,采用湿消解-电感耦合等离子体发射光谱法(ICP-AES)测定药用胶囊中的铬含量.在0～80 ng/mL范围内,铬的浓度与发射光强度呈良好的线性关系,相关系数r=0.999 98,检出限为1.42 ng/mL.对3个浓度水平的铬标准溶液进行平行测定,测定结果的相对标准偏差为1.43％～1.79％(n=6),加标回收率为93.1％ ～110.0％.该方法可以用于药用胶囊中铬的日常检测.     

Complete noncompact manifolds with harmonic curvature

Let (M ⁿ , g) be an n-dimensional complete noncompact Riemannian manifold with harmonic curvature and positive Sobolev constant. In this paper, by employing an elliptic estimation method, we show that (M ⁿ , g) is a space form if it has sufficiently small L ^n/2-norms of trace-free curvature tensor and nonnegative scalar curvature. Moreover, we get a gap theorem for (M ⁿ , g) with positive scalar curvature.     

Y2O3掺杂WO3光催化剂的制备及其性能

采用浸渍法合成了Y2O3 -WO3光催化剂,通过XRD和UV-Vis DRS测试手段对其进行了表征.以对苯二甲酸为探针分子,结合化学荧光技术研究了Y2O3 -WO3表面羟基自由基的生成.以溴百里香酚蓝(BTB)催化降解实验评价了其光催化活性.结果表明:与纯WO3相比,1.2％ Y2O3-WO3样品的吸收带边发生明显红移、在200～800 nm 区域有更强的光吸收.Y2O3-WO3样品的紫外和可见光催化活性随Y2O3含量增加先增加,当Y2O3含量为1.2％时分别达到最大值,然后随Y2O3含量的进一步增加而减小.与纯WO3相比,1.2％ Y2O3-WO3样品明显具有更高的紫外和可见光催化活性以及更大的羟基自由基生成速率.     

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建立了包含两种正离子的碰撞等离子体鞘层的流体模型,通过四阶龙格-库塔法模拟了碰撞对含有两种正离子的等离子体鞘层中的离子密度和速度分布产生的影响。结果表明,对于两种正离子的等离子体来说,鞘层中无论哪种离子与中性粒子碰撞频率的增加,该种离子的密度和速度分布都将呈现波动变化,密度是先增加后降低,速度是先降低后增加;而另一种离子的密度和速度呈单调变化。鞘边正离子的含量越少,受自身与中性粒子的碰撞频率增加,鞘层中该种离子密度先增加后降低的变化位置就越远离等离子体的鞘层边界。同时发现该种离子密度分布受自身碰撞频率增加,降低的幅度变化非常小。另外发现电子碰撞器壁产生的二次电子发射系数对质量较轻的离子影响要大一些。     

Interaction behavior study of HCl on (ZnS)n (n = 1–12) clusters and HCl effect on Hg0 adsorption

The interaction behavior of HCl and (ZnS)_n (n = 1–12) clusters and HCl effect on Hg⁰ adsorbed by (ZnS)_n have been studied theoretically. The combined genetic algorithm and density functional theory (GA-DFT) method has been used to obtain the structures of (ZnS)_nHCl and (ZnS)_nHgHCl (n = 1–12) clusters. The structural properties of (ZnS)_nHCl and (ZnS)_nHgHCl have been analyzed. The adsorption energies and interaction energies have been calculated. Bond length and bond order analysis has revealed that S H and Zn Cl bonds form after HCl adsorbed on (ZnS)_n clusters, while Hg⁰ can only weakly bind with (ZnS)_nHCl clusters. According to thermodynamic adsorption analysis, the formation of (ZnS)_nHCl clusters from (ZnS)_n and HCl are spontaneous because of their negative Gibbs free energy changes. The formation of (ZnS)_nHgHCl from (ZnS)_nHCl and Hg are nonspontaneous for n = 1–4 and 9, and the Gibbs free energy changes have small negative values for other sizes. Electron localization function and noncovalent interaction (NCI) analysis of (ZnS)₁₀HgHCl manifest that Hg and its nearest Zn form zinc amalgam. Projected density of state study has been performed to obtain the interaction nature of HCl and (ZnS)_n clusters and Hg⁰ adsorption on (ZnS)_nHCl clusters. Based on our study, HCl is chemical adsorbed by (ZnS)_n clusters except (ZnS)₄ cluster. After (ZnS)_n adsorbs HCl, Hg⁰ can physically adsorb on (ZnS)_nHCl clusters. The strength of Hg⁰ on (ZnS)_nHCl is comparable to that of Hg⁰ on (ZnS)_n, indicating that HCl can hardly affect the adsorption of Hg⁰ on ZnS clusters.     

重建Cole-Cole模型参数的时域微波乳腺筛查技术

提出一种时域微波层析成像新技术，分别通过非线性最优化方法、正则化方法、Cole-Cole建模方法，有效地克服了时域微波成像技术在筛查早期乳腺肿瘤出现的成像问题非线性、病态特性及乳腺组织色散特性等困难.在二维的数值算例中，考虑噪声影响，仿真结果初步证实：该技术检测小尺寸乳腺肿瘤是可行的；易于发现浅层肿瘤；且反演静态电导率的精度最高.     

Modified Ringel-Hall algebras,naive lattice algebras and lattice algebras

For a given hereditary abelian category satisfying some finiteness conditions, in certain twisted cases it is shown that the modified Ringel-Hall algebra is isomorphic to the naive lattice algebra and there exists an epimorphism from the modified Ringel-Hall algebra to the lattice algebra. Furthermore, the kernel of this epimorphism is described explicitly. Finally, we show that the naive lattice algebra is invariant under the derived equivalences of hereditary abelian categories.     

HNCO在201 nm的离子成像光解动力学:CO(X1Σ+)与NH(a1Δ)

本文通过时间切片离子速度成像技术在201 nm附近研究了HNCO分子在S₁电子激发态的光解动力学. CO产物通过共振增强多光子电离的方法进行了选态探测，获得了CO产物的振动基态和激发态切片影像. 从CO的影像得到了解离产物的能量分布和空间角分布，确定了NH(a¹Δ)产物的振转态分布信息. 研究发现¹NH的振动分支比(v=1/v=0)随CO(v=0)转动能的增大先增大后下降，展现了¹NH与CO之间特殊的态态相关性. 大约一半的可资用能分配给解离产物的平动自由度. 负的各向异性参数表明HNCO的光解是个快速的直接解离过程.     

NiO、CuO在γ-Al2O3表面分布问题的探究——第21届全国化学竞赛决赛第6题的解析

对一个全国高中化学竞赛(决赛)试题晶体部分NiO、CuO在γ-Al2O3表面的分布问题进行分析、探究,并对试题问题的设置进行了整合重组和新的设计.