Comment on "Further improvement on delay-range-dependent robust absolute stability for Lur׳e uncertain systems with interval time-varying delays" by P. Liu [ISA Trans. 58(2015)58-66].

In a recent paper (ISA Transactions (2015)58: 58-66), an integral inequality has been proposed to reduce the conservativeness of stability conditions for Lur׳e uncertain systems. We point out that there exist some errors in Theorems 1-8, and the correct theorems are presented. Finally, the allowable maximum admissible upper bound (MAUB) listed in Tables 1-5 have been recalculated by using the correct results.

[Tree species diversity of tropical montane rain forest in Xishuangbanna, Yunnan].

Tropical montane rain forest (TMR), one of the main forest vegetation types in Xishuangbanna of Yunnan Province, occurs horizontally in the north (TMRF I) and vertically in the south (TMRF II). In order to understand its tree species diversity in different zones, six fixed plots (50 m x 50 m) at different sites in Xishuangbanna were established, two (plots 1 and 2) for TMRF I, and four (plots 3, 4, 5 and 6) for TMRF II. Grid method (10 m x 10 m) was used to record all the individuals with DBH greater than 2.0 cm in each plot, and tree species richness and diversity characteristics along DBH class, as well as changing trend of tree species diversity with increasing sampling area were analyzed. The results showed that the tree stem and species richness in the six plots both declined constantly along the DBH class gradient. For the communities of TMRF I (altitude was 850 1000 m), all indices had no clear trend with the gradient, while for the communities of TMRF II (altitude 1 200 - 2000 m), Shannon-Wiener and Simpson indices declined constantly with gradient, but Pielou's evenness index had the opposite trend. In smaller DBH classes (> or =2 cm, > or =5 cm and > or =10 cm), the tree species richness, diversity, and evenness of the communities of TMRF II were obviously higher than those of the communities of TMRF I, but there was no difference between the communities of TMRF I and TMRF II in larger DBH classes (> or = 20.0 cm, > or =30.0 cm and > or =50.0 cm) . With sampling area increased, the tree species richness, Shannon-Wiener index, Simpson index and Pielou's evenness index of the six plots all had the trend to be smooth when the sampling area increased to 2 000 m2.

Three-dimensional morphological chirality induction using high magnetic fields in membrane tubes prepared by a silicate garden reaction.

Using a vertical superconducting magnet (max. 15 T), we studied magnetic field effects on membrane tube morphology prepared by a silicate garden reaction. At zero field, semipermeable membrane tubes grew upward when metal salts were added to a sodium silicate aqueous solution. In the presence of a magnetic field (15 T, downward) right-handed helical membrane tubes grew along a glass vessel's inner surface when magnesium chloride and copper sulfate were added. Referring to membrane tubes by the names of metal cations used in their preparation, in the case of Mg(II) and Zn(II) membrane tubes, the left-handed helical tubes grew when the field direction was reversed upward. The left-handed helical Mg(II) membrane tubes grew in the magnetic field when a glass rod was placed in a vessel. Mg(II) and Zn(II) tubes, separate from a vessel wall, grew in a twisted shape in the magnetic field. In situ observation of the solution's motion during the reaction revealed that the Lorentz force on the outflow from the opened top of the hollow membrane tube induced convection of the solution near the tube exit, engendering chiral growth of the membrane tubes. Relative orientation of the outflow and a boundary (a vessel wall or glass rod surface) helped to determine the convection's direction.