An example of applications of the elementary catastrophe theory in Hamiltonian systems

The convection in atmosphere discussed in ref. [1] is rigorously treated by considering the variation of environmental temperature with the height. This represents an example of applications of the elementary catastrophe theory in Hamiltonian systems.     

Electrogenerated Chemiluminescence Based on Tris(2,2′-bipyridyl) Ruthenium(II) with Hydroxyl Carboxylic Acid

Upon the electrochemical oxidation of tris(2,2′-bipyridyl) ruthenium(II) [Ru(bpy)²⁺₃] and hydroxyl carboxylic acids, for instance, citric acid, tartaric acid, malic acid, and -gluconic acid, bright electrochemiluminescences (ECLs) were observed. Different luminescent reactions were presented depending on the applied potential. The light emission was mainly caused by the reaction between alkoxide radical ion and Ru(bpy)³⁺₃below the potential +1.80 V (vs Ag/AgCl). The luminescence intensity obviously increased because of the more complex reaction process. The luminescence wavelength of 608 nm, which could be found either at higher potential than +1.80 V or in the potential range from +1.30 to +1.80 V, confirmed that ECL was caused by Ru(bpy)²⁺₃*. The factors which affect the determination and HPLC separation of the four acids were also investigated.     

羧甲基壳聚糖对胆红素的吸附性能研究

合成了不同取代度的羧甲基壳聚糖(CM-CTS)作为吸附剂，研究了不同条件对CM-CTS吸附胆红素性能的影响．结果表明：在实验条件下，随着羧甲基取代度的增加和体系温度的升高．最大吸附率和吸附速率均相应增加：在接近人体血液pH值的条件下，CM-CTS对胆红素的吸附性能较佳：人血清白蛋白和离子强度的增加对CM—CTS吸附胆红素有明显的抑制作用。     

Mössbauer Spectroscopic Studies of Ferrocenylaldimines and their TCNQ Complexes

A series of ferrocenylaldimines (Fc-CH=N-R) has been prepared by Schiff base condensation of formylferrocene with polyacenylamines RNH₂ where R = naphthyl, 5,6,7,8-tetrahydronaphthyl, anthracenyl, and pyrenyl groups. This step was followed by oxidation with TCNQ to give [Fc-CH = N-R][TCNQ]² salts. The electronic state of iron in these compounds was investigated by means of⁵⁷Fe Mössbauer spectroscopy.     

Synthesis and formulation of vinyl-containing polyacids for improved light-cured glass-ionomer cements

Vinyl-containing poly(acrylic acid-co-itaconic acid) copolymers were synthesized and used to formulate light-curable cements containing reactive glass fillers (Fuji II LC). The conditions for light curing were studied and optimized. Effects of molecular weight (MW), grafting ratio, comonomer, liquid composition, powder/liquid (P/L) ratio, glass powder and aging were evaluated. The results show that the vinyl-containing glass-ionomer cements (GICs) prepared in this study exhibit higher compressive strength (CS, 225.6 MPa), diametral tensile strength (DTS, 28.4 MPa) and much higher flexural strength (FS, 116.4 MPa), as compared to commercial Fuji II LC GIC (186.6 in CS, 19.1 in DTS and 57.1 in FS). The optimal light-exposure time was found to be around 10 min, and concentrations of CQ and DC were 0.5% (by weight) and 1.0%, respectively. Effects of MW, grafting ratio, P/L ratio and content of polymer in the liquid formulation were significant. The highest strengths were found for the optimal formulations where the MW was 15,000 (weight average), grafting ratio 25 mol%, P/L ratio 2.7 and liquid composition 50:20:30. During aging, the cement showed an increase of strength over the first week and then no change for a month. SEM analysis suggests that more integrated microstructures and smaller glass particles can lead to higher FS and higher polymer content in GICs leads to tough fracture surface and plastic deformation.     

Synthesis of a novel 18β-glycyrrhetinic acid derivative

A novel compound, biotinylated 18β-glycyrrhetinic acid (BGA), was synthesized. It is a compound of 18β-glycyrrhetinic acid linked with biotin. Published in Khimiya Prirodnykh Soedinenii, No. 3, pp. 266–267, May–June, 2006. An erratum to this article is available at .