非线性0-1规划问题的蜂群算法

针对非线性0-1规划,提出采用一种智能优化算法——蜂群算法进行求解.描述了蜂群算法的实现过程,并在计算机上编程予以实现.经大量实例测试,并与其它算法进行比较,获得了满意的结果.说明了蜂群算法在解决非线性0-1规划问题上的可行性与有效性,同时具有良好的优化能力..     

模糊人工蜂群算法的多选择多维背包问题求解

针对传统人工蜂群算法早熟收敛问题,基于模糊化处理和蜂群寻优的特点,提出一种模糊人工蜂群算法。将模糊输入输出机制引入到算法中来保持蜜源访问概率的动态更新。根据算法计算过程中的不同阶段对蜜源访问概率有效调整,避免算法陷入局部极值。通过对多选择多维背包问题的仿真实验和与其他算法的比较,表明本算法可行有效,有良好的鲁棒性。     

An Analytical Method for the Biomonitoring of Mercury in Bees and Beehive Products by Cold Vapor Atomic Fluorescence Spectrometry

Bees and their products are useful bioindicators of anthropogenic activities and could overcome the deficiencies of air quality networks. Among the environmental contaminants, mercury (Hg) is a toxic metal that can accumulate in living organisms. The first aim of this study was to develop a simple analytical method to determine Hg in small mass samples of bees and beehive products by cold vapor atomic fluorescence spectrometry. The proposed method was optimized for about 0.02 g bee, pollen, propolis, and royal jelly, 0.05 g beeswax and honey, or 0.1 g honeydew with 0.5 mL HCl, 0.2 mL HNO₃, and 0.1 mL H₂O₂ in a water bath (95 °C, 30 min); samples were made up to a final volume of 5 mL deionized water. The method limits sample manipulation and the reagent mixture volume used. Detection limits were lower than 3 µg kg⁻¹ for a sample mass of 0.02 g, and recoveries and precision were within 20% of the expected value and less than 10%, respectively, for many matrices. The second aim of the present study was to evaluate the proposed method’s performances on real samples collected in six areas of the Lazio region in Italy.     

Microcalorimetric investigations on the influence of propolis on the bacterium micrococcus luteus

Propolis or bee-glue is the third important product of honey bees after honey and wax. Known for thousands of years for its curative effects it is finding evermore attention in alternative and classical therapy in recent times against, e.g. infections, inflammations, dermatologic diseases and in wound healing.

Microcalorimetric experiments were performed on the influence of several propolis samples from Germany, Uruguay, Ethiopia and of a commercial propolis tincture on growth and metabolism of the recommended gram-positive bacterium Micrococcus luteus. Propolis extracts were prepared following established recipies for the water-soluble and insoluble components and the precipitate.

Addition of these extracts to a growing M. luteus culture in different growth phases resulted in a strong decline of the heat production rate, a prolongation of the lag phase or an introduction of a new, second lag phase, while the form of the calorimetric power-time curve remained unchanged. The calorimetric response showed a linear dependence on the propolis concentration. Although the quantitative gain of the extracts from the different propolis samples was nearly constant, the effects varied considerably between the specimens used.

The calorimetric investigations were supplemented by polarographic oxygen monitoring and by the standard agar well technique to determine the growth inhibition factor of the propolis extracts.     

Novel Synthesis of a 2H-1,2-Benzothiazine -1,1-Dioxide Derivative

We report a novel synthesis of 4-chloro-2-cyclohexyl-6,7-dimethoxy-2H-1,2-benzothiazine-1,1-dioxide 6 from 3,4-dimethoxychalcone 1. Chlorosulfonation of 1 followed by amination, then epoxidation under basic conditions with immediate elimination of the benzoyl group and electrophilic chlorination resulted in 6. A mechanism is suggested.     

The Hexagonal Honeycomb Conjecture

It is conjectured that the planar hexagonal honeycomb provides the least-perimeter way to enclose and separate infinitely many regions of unit area. Various natural formulations of the question are not known to be equivalent. We prove existence for two formulations. Many questions remain open.