Benzimidazole-based anion receptors exhibiting selectivity for lactate over pyruvate

The influence of anions on tautomerism in benzimidazole containing anion receptors has been studied via a variety of techniques in both solution and the solid state. The results show that hydrogen bonding interactions between the receptors and guests have a significant effect of the nature of the tautomer present. The compounds show a preference for complexation of lactate over pyruvate.     

Functionalisation of fluorescent BODIPY dyes by nucleophilic substitution

The BODIPY chromophore can be easily modified by nucleophilic mono- or disubstitution of 3,5-dichloroBODIPY with O-, N-, S- and C-nucleophiles. Absorption and fluorescence spectral data of the new BODIPY derivatives are also reported.     

Population Growth and Nash Equilibria Under Viability Constraints in the Commons

Population growth modifies the optimal equilibrium between a stationary population and its resource, producing instead a line of equilibria, characterized by fluctuating population size, resource quantity, harvest per head, and birth rates. The Pontryagin procedure allows the analytical expression of the Nash equilibria for two populations sharing a common resource and capable of growth. An alternative procedure, which avoids solving differential equations and inherently includes state constraints, involves building the capture-viability kernel of an auxiliary system. For two populations, all Nash equilibria under state constraints are obtained as the intersection of the boundaries of two capture-viability kernels. The two methods, Pontryagin and viability, yield concordant results. Viability is more flexible and avoids solving differential equations for each initial condition.     

蒽、菲异构体在用甲基苯基聚硅氧烷改性的氯化镉柱上的色谱性能

用甲基苯基聚硅氧烷改性的氯化镉柱(MPS-CdCl_2)基线分离了蒽、菲异构体。蒽、菲的相对保留值(α_(a/p))和调整保留时间(t’R)随氯化镉含量的提高而增大。MPS-CdCl_2。柱选择性好,柱效稳定。     

柱芯电极光谱法测定西藏斑岩铜矿中的铜,钼,银,铅,锌,砷,钨和铋

本文研究了柱芯电极测定西藏斑岩铜矿中8个主次要元素,并与用其他电极测定的结果进行了对比实验。本文还讨论了组分影响及消除方法。对铜矿区样品测定,其RSD(n=15)为Cu±3.3%,Mo±4.1%,Ag±3.7%,Pb±6.5%。Zn±6.5%,As±7.3%,W±6.9%以及Bi±6.9%。用化学分析,外检和标样验证了方法的可靠性。     

原子吸收法测定硅藻土中的铁,钙和镁

通过Al、SiO_2、HClO_4对Fe、Ca、Mg原子吸收法测定干扰的研究,对仪器工作条件、溶样方法的研究,建立了原子吸收法测定硅藻土中Fe、Ca、Mg的分析方法。此法测定Fe、Ca、Mg的相对标准偏差分别是Fe<2.0%、Ca<9.0%、Mg<10.0%,三元素回收率均在94-106%之间。     

土壤中常量及微量元素的ICP光谱分析

本文叙述了土壤中Ca、Mg、Na、Sr、Ba、Mn、Fe、V、Cr及Ti等元素简单快速的ICP-AES测定方法。用HClO_4、HNO_3及HF在聚四氟乙烯高压罐中溶解祥品,用H_3BO_3络合过量的HF。采用基体匹配法校正干扰。方法的准确度、精密度及检出限均较好。     

冷蒸气原子吸收光谱法测定铜精矿中的汞

本文研究了一种用冷蒸气原子吸收光谱测定铜精矿中汞的方法。铜精矿用逆王水或硫酸-高锰酸钾(固)消化后用测汞仪测定其中的汞含量。测定结果的相对标准偏差小于5%;回收率在92-107%之间。