High-Strength Carbon Nanotube Fibers from Purity Control by Atomized Catalytic Pyrolysis and Alignment Improvement by Continuous Large Prestraining.

Transferring the high strength of individual carbon nanotubes (CNTs) to macroscopic fibers is still a major technical challenge. In this study, CNT fibers are wound from a hollow cylindrical assembly. In particular, atomized catalytic pyrolysis is utilized to produce the fiber and control its purity. The pristine fiber is then continuously prestrained to have a highly aligned structure for subsequent full densification. Experimental measurements show that the final fiber possesses a high tensile strength (8.0 GPa), specific strength (5.54 N tex-1 (tex: the weight (g) of a fiber of 1 km long)), Young's modulus (350 GPa), and elongation at break (4%). Such an excellent combination is superior to that of any other existing fiber and attributed to the efficient stress transfer among the highly aligned and packed CNTs. Our study provides a new strategy involving atomized catalysis for developing superstrong CNT assemblies such as fibers and films for practical applications.

Large improvement of the tensile strength of carbon nanotube films in harsh wet environments by carbon infiltration.

Carbon nanotube (CNT) materials show large degradation in tensile strength when they are exposed in chemically active environments due to the loss of inter-tube bonding. Here, we report the suppression of such degradation by chemical vapor infiltration of amorphous carbon into CNT films. The amorphous carbon generated by the thermal decomposition of the gaseous hydrocarbon of acetylene is firmly bonded on the CNT sidewalls and intersections. Based on the improved inter-tube bonding and restriction of inter-tube sliding, the tensile strength of the film is improved to be 3 times of the original level. More importantly, the bonding is so strong and stable that the high tensile strength remains with little loss even in harsh wet environments such as boiling alcoholic, acidic, alkaline solutions and seawater. Such harsh environments-tolerant properties, which were rarely observed before, could open new windows for the CNT/C composite material to be applied from functional devices to structural components under extreme corrosive conditions.

Taxonomic notes on the Chinese endemic genus Straneostichus Sciaky, 1994 (Coleoptera: Carabidae: Pterostichini), with descriptions of three new species.

A total of eleven species and two subspecies are recognized within the Chinese endemic genus Straneostichus Sciaky, 1994 (Carabidae: Pterostichini), including three new species described in the present paper: Straneostichus politus sp. nov. (Sichuan: Wolong), Straneostichus liupanensis sp. nov. (Ningxia: Liupanshan) and Straneostichus ganqingensis sp. nov. (Qinghai: Mengda and Gansu: Dangchang). Taxonomical notes and new distribution records for all the known species are provided, along with an updated key to the species of Straneostichus.

Revision of the Chinese species of subgenus Koreonialoe (Coleoptera: Carabidae: Pterostichus), with descriptions of two new species.

The Chinese species of subgenus Koreonialoe Park & Kwon, 1996 of the genus Pterostichus are revised, including four species from the eastern part of Jilin and Liaoning provinces. Two new species are described: Pterostichus (Koreonialoe) micropoidessp. nov. (type locality: Jilin, Changbai county), and Pterostichus (Koreonialoe) tetralobatussp. nov. (type locality: Liaoning, Xiuyan county). Pterostichus (Koreonialoe) bellatrix (Tschitschérine) is newly recorded from China (Jilin). The subgenus Koreonialoe is classified into two groups on account of their differences on the endophallus, and all Chinese species accord with the microps group defined herein. A key to all six species in the microps group is provided.

Description of a new species of Megischus Brullé (Hymenoptera, Stephanidae), with a key to the species from China.

A new species of the genus Megischus Brullé, 1846, Megischus kuafu Ge & Tan, sp. nov., is described and illustrated from Guizhou Province, China. The key to all four species from China is included. A distribution map of the Chinese species is added.

The first record of the genus Belenois (Lepidoptera: Pieridae) from China.

BACKGROUND: The family Pieridae is a large group of butterflies which plays an important role in evolutionary biology and contains many potential pests (Courtney 1986). Pieridae is a cosmopolitan family while the tropics harbour higher species richness. In a very recent expedition to the Chinese-Indian border area in Tibet Autonomous Region, a migratory species, Belenois aurota (Fabricius, 1793), was discovered for the first time, which comprises the first record of the genus Belenois in China and the highest altitude record of this species. NEW INFORMATION: The species B. aurota (Fabricius, 1793) is the first record of the genus Belenois from China. The specimen was collected at an altitude of about 3,000 m in Tibet Autonomous Region. Relevant details are presented for the species.

A Cretaceous bug with exaggerated antennae might be a double-edged sword in evolution.

Sexual selection can favor production of exaggerated features, but the high cost of such features in terms of energy consumption and enemy avoidance makes them go to extinction under the influence of natural selection. However, fossils preserved with specialized features are very rare. Here, we report a new nymph from Burmese amber, Magnusantena wuae Du & Chen gen. et sp. nov., which has exaggerated leaf-like expanded antennae. Such bizarre antennae indicate that sensitive and delicate sensory system and magnificent appearance in Hemiptera have been already established in mid-Cretaceous. Our findings may provide evidence for Darwin's view that sensory organs play an important role in sexual selection. This nymph with the leaf-like antennae may also represents a new camouflage pattern. However, the oversized antennae are costly to develop and maintain, increasing the risks from predators. Such unparalleled expanded antennae might be the key factor for the evolutionary fate of the coreid.

Lewis Base-Catalyzed [4 + 3] Annulation of ortho-Quinone Methides and MBH Carbonates: Synthesis of Functionalized Benzo[ b]oxepines Bearing Oxindole Scaffolds.

A novel Lewis base-catalyzed [4 + 3] annulation process for the construction of benzo[ b]oxepine scaffolds has been developed. 1,4-Diazabicyclo[2.2.2]octane (DABCO) promotes the union of o-QMs and Morita-Baylis-Hillman carbonates in reasonable to excellent yields and good stereoselectivities (dr > 20:1). This straightforward, catalytic approach offers access to a variety of synthetically useful benzo[ b]oxepine derivatives bearing oxindole scaffolds containing all-carbon spiro-quaternary stereocenters.