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It is shown that the two-component Camassa—Holm and Hunter—Saxton systems are geometrically integrable, namely they describe pseudo-spherical surfaces. As a consequence, their infinite number of conservation laws are directly constructed. In addition, a class of nonlocal symmetries depending on the pseudo-potentials are obtained.

The axis of the integrated superluminescent light source was tilted with respect to the output facet normal for lasing suppression. A new phenomenon (lasing suppression) was observed in the tilted integrated device. Three new schemes were proposed and demonstrated further to suppress the lasing by analysing the reason for lasing in the tilted structure. The lasing was suppressed successfully at high pumping levels, and high superluminescent powers (more than 300 mW) were obtained at a pulsed condition with the spectral full width at half maximum of 25-30 nm.

A polarographic catalytic wave of human serum albumin (HSA) in the presence of KIO3 was reported. In 0.1 M NaAc∼HAc buffer (pH4.7) solution, a reduction wave of HSA with peak potential −0.60 V (vs., Ag/AgCl) resulted from the reduction of five disulfide linkages to sulfhydryl group. In the presence of KIO3, HSA yielded a polarographic catalytic wave at the original potential due to reduction and regeneration of these disulfide linkages. The catalytic wave can be used to determine trace of HSA. In the 0.1 M HAc∼NaAc (pH4.7±0.2) ∼1×10−3 M KIO3 solution, the peak current was linearly proportional to HSA concentration in the range of 1.5×10−7∼7.5×10−7 M. The catalytic wave improved two orders of magnitude in sensitivity compared with corresponding reduction wave.

A method for the determination of glycyrrhizic acid (GA) is described based on polarographic current of GA enhanced doubly by both cation surfactant (cetyl trimethyl ammonium bromide (CTMAB)), and dissolved oxygen (including oxygen-derived species). The doubly enhanced current of GA includes two additional currents. One is the increased reduction current of adsorbed GA induced by CTMAB. The other is the catalytic current of GA caused by the dissolved oxygen molecule and its derived species. In 0.1 M NaAc-Hac (pH4.7±0.1) ∼ 1x10−5 M CTMAB supporting electrolyte without deoxygenation, the enhanced current of GA is linearly proportional to its concentration in the range of 4x10−7 M ∼ 4.0x10−6 M. The detection limit is 1.8x10−7 M. The double enhanced current of GA in sensitivity is about 15 times higher than its reduction wave in the same acetate buffer solution.