The oscillatory behavior of a double-walled carbon nanotubes with a rotating inner tube is investigated using molecular dynamics simulation. In the simulation, one end of the outer tube is assumed to be fixed and the other is free. Without any prepullout of the rotating inner tube, it is interesting to observe that self-excited oscillation can be triggered by nonequilibrium attraction of the ends of two tubes. The oscillation amplitude increases until it reaches its maximum with decrease of the rotating speed of the inner tube. The oscillation of a bitube is sensitive to the gap between two walls. Numerical results also indicate that the zigzag/zigzag commensurate model with a larger gap of >0.335 nm can act as a terahertz oscillator, and the armchair/zigzag incommensurate model plays the role of a high amplitude oscillator with the frequency of 1 GHz. An oblique chiral model with a smaller gap of <0.335 nm is unsuitable for the oscillator because of the steep damping of oscillation.

Rotation of the inner tube in a double-walled carbon nanotube (DWCNT) system with a fixed outer tube is investigated and found to be inducible by a relatively high uniform temperature (say, 300 K). We also found the mechanism of a gradientless temperature-driven rotating motor lies in the inner tube losing its geometric symmetry in a high-temperature field. This mechanism can be taken as a guide for designing a motor from such a bi-tube system. Using a computational molecular dynamics (CMD) approach and the adaptive intermolecular reactive empirical bond order (AIREBO) potential, the dynamic behavior of a bi-tube system subjected to uniformly distributed temperature is studied. In particular, the effects of environmental temperature, boundary conditions of the outer tube, and intertube gap on the dynamic behavior of the bi-tube system are investigated. Numerical examples show that a bi-tube system with the inner tube having 0.335 nm of interlayer gap produces the highest rotational speed.

The diversity of lignin-degrading bacteria in Qinling Mountain is revealed. The study of Burkholderia sp. H1 expands the range of bacteria for lignin degradation and provides novel bacteria for application to lignocellulosic biomass.

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Background:The ZIF-8-coated magnetic regenerated cellulose-coated nanoparticles (ZIF-8@cellu@Fe 3 O 4 ) were successfully prepared and characterized. The result showed that ZIF-8 was successfully composited on to the surface of the cellulose-coated Fe 3 O 4 nanoparticles by co-precipitation method. Moreover, the glucose oxidase (GOx, from Aspergillus niger) was efficiently immobilized by the ZIF-8@Cellu@Fe 3 O 4 nanocarriers with enhanced catalytic activities. The enzyme loading was 94.26 mg/g and the enzyme activity recovery was more than 124.2%. This efficiently immobilized enzyme exhibits promising applications in biotechnology, diagnosis, biosensing, and biomedical devices. Conclusions:A new core-shell magnetic ZIF-8/cellulose nanocomposite (ZIF-8@Cellu@Fe 3 O 4 ) was fabricated and structurally characterized. Glucose oxidase (GOx) was successfully immobilized by the biocompatible ZIF-8@Cellu@