Electric field controlled formation and dissociation of multiwalled carbon nanotube (MWCNT) conductive pathways in a polycarbonate (PC) melt are investigated by the dynamic percolation measurement. The results show that field-induced MWCNT alignment causes the decrease in the activation energy of conductive pathway formation. The directional or disordered alignment of MWCNTs in the PC melt results in the transition from a conductor to an insulator as the electric field changes from 500 to 1 V/cm. This electric-controllable directional or disordered alignment technology is promising for the fabrication of low-dimensional conductive materials and applications of voltage-switch devices.

A novel strain of the classActinobacteriawas isolated from a seawater sample collected in the South China Sea using modified R2A agar plates. The strain was a Gram-stain-positive, non-motile, non-spore-forming, catalase-positive, irregular rod-shaped bacterium. The strain grew at 4–45 °C and pH 5.0–10.2, and tolerated 5 % (w/v) NaCl. Based on its 16S rRNA gene sequence, the organism was related phylogenetically to members of the generaFodinibacter(96.7 % similarity),Lapillicoccus(96.5 %),Knoellia(95.0–95.8 %),Oryzihumus(95.6 %) andHumibacillus(95.6 %). The cell-wall containedl-ornithine as the major diagnostic diamino acid in the peptidoglycan. MK-8(H₄) was the predominant menaquinone. Major cellular fatty acids were iso-C_18 : 1ω9c, iso-C_16 : 0, iso-C_15 : 0and C_17 : 0. The G+C content of the DNA was 69.6 mol%. Phenotypic and phylogenetic data revealed that this strain represents a novel species in a new genus of the familyIntrasporangiaceae, for which the nameOrnithinibacter aureusgen. nov., sp. nov. is proposed; the type strain ofOrnithinibacter aureusis HB09001^T(=CGMCC 1.10341^T=DSM 23364^T).

The double asymptotic homogenization method originated for analyzing physical systems containing two or more length scales was adopted to predict the characteristic of 1-3 type cement-based piezoelectric composites for the first time. The piezoelectric properties of 1-3 type cement-based piezoelectric composites were measured and comparisons between the experimental data and predicted values validate the effectiveness of the present analytical model. Moreover, numerical discussions and experiments show that one should choose proper volume fraction of constituents to achieve the best performance of the 1-3 type cement-based piezoelectric composites.

This paper examines the accuracy and effectiveness of various beam theories in predicting the critical buckling loads and fundamental frequencies of functionally graded porous (FGP) beams whose material properties change continuously across the thickness. The beam theories considered are classical beam theory (CBT), first-order shear deformation beam theory (FSDBT), third-order shear deformation beam theory (TSDBT), and the broken-line hypothesis-based shear deformation beam theory (BSDBT). Governing equations for those beam theories are formulated by using the Hamilton’s principle and are then solved by means of the generalised differential quadrature method. Finite element simulation solutions are provided as reference results to assess the predictions of those beam theories. Comprehensive numerical results are presented to evaluate the influences of the porosity distribution and coefficient, slenderness ratio, and boundary condition on the difference between theoretical predictions and simulation results. It is found that the differences significantly increase as the porosity coefficient rises, and this effect becomes more noticeable for the rigid beam with a smaller slenderness ratio. Nonetheless, the results produced by the BSDBT are always the closest to simulation ones. The findings in this paper will contribute to the establishment of more refined theories for the mechanical analysis of FGP structures.