We provide a wet chemical approach for organizing randomly tangled single-walled carbon nanotubes (SWCNTs) on gold surfaces. The as-grown nanotubes were first chemically cut into short pipes and thiol-derivatized at the open ends. The ordered assembly of SWCNTs was made by their spontaneous chemical adsorption to gold via Au−S bonds. Tapping mode atomic force microscopy (AFM) images clearly show that the nanotubes have been organized on gold, forming a self-assembled monolayer structure with a perpendicular orientation. The adsorption kinetics of the nanotubes was very slow in comparison to conventional alkanethiols. The adsorption rate varied inversely with tube length. The nanotubes tend to form bundles as the adsorption propagates, following a “nucleation adsorption mechanism”. This work demonstrates that “giant” carbon nanotubes can be assembled on Au surfaces using wet chemistry similar to that exploited for “small” organic self-assembling species. We believe that assembled nanotube arrays will provide wide possibilities for applications.

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The Tibetan antelope (Pantholops hodgsonii) is endemic to the extremely inhospitable high-altitude environment of the Qinghai-Tibetan Plateau, a region that has a low partial pressure of oxygen and high ultraviolet radiation. Here we generate a draft genome of this artiodactyl and use it to detect the potential genetic bases of highland adaptation. Compared with other plain-dwelling mammals, the genome of the Tibetan antelope shows signals of adaptive evolution and gene-family expansion in genes associated with energy metabolism and oxygen transmission. Both the highland American pika, and the Tibetan antelope have signals of positive selection for genes involved in DNA repair and the production of ATPase. Genes associated with hypoxia seem to have experienced convergent evolution. Thus, our study suggests that common genetic mechanisms might have been utilized to enable high-altitude adaptation.

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Samples were sawn into slabs and the central parts (4200 g) were used for bulk-rock analysis. The rocks were crushed into small fragments (50•5 cm in diameter) before being further cleaned and powdered in a corundum mill. Bulk-rock geochemical analyses were carried out at the Guangzhou Institute of Geochemistry, Chinese Academy of Sciences. Bulk-rock major element oxides were analyzed by X-ray fluorescence (XRF) with analytical uncertainties better than 3% for SiO 2 , Al 2 O 3 , Fe 2 O 3 , MgO, CaO, Na 2 O and K 2 O, and better than 5% for TiO 2 , MnO and P 2 O 5. Trace elements were analyzed by inductively coupled plasma-mass spectrometry (ICP-MS). Repeated runs give 53% RSD (relative standard deviation) for most trace elements analyzed. Fe/Mn ratios

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Abstract. Super-elastic collision is an abnormal collisional process, in which some particular mechanisms cause the kinetic energy of the system increasing. Most studies in this aspect focus on solid-like objects, but they rarely consider gases or liquids, as the collision of the latter is primarily a mixing process. With cross-field diffusion being effectively prohibited, magnetized plasmoids are different from ordinary gases. But it remains unclear how they act during a collision. Here we present the global picture of a unique collision between two coronal mass ejections in the heliosphere, which are the largest magnetized plasmoids erupting from the Sun. Our analysis for the first time reveals that these two magnetized plasmoids collided like solid-like objects with a 73% likelihood of being super-elastic. Their total kinetic energy surprisingly increased by about 6.6% through the collision, which significantly influenced the dynamics of the plasmoids.

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