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Recent attention has been focused on the synthesis and application of complex heter ostructured nanomaterials, which can have superior electrochemical performance than singlestructured materials. Here we synthesize the threedimensional (3D) multicomponent oxide, mnmoo 4 /Comoo 4 . Hierarchical heterostructures are successfully prepared on the backbone material mnmoo 4 by a simple refluxing method under mild conditions; and surface modification is achieved. We fabricate asymmetric supercapacitors based on hierarchical mnmoo 4 /Comoo 4 heterostructured nanowires, which show a specific capacitance of 187.1 F g − 1 at a current density of 1 A g − 1 , and good reversibility with a cycling efficiency of 98% after 1,000 cycles. These results further demonstrate that constructing 3D hierarchical heterostructures can improve electrochemical properties. 'oriented attachment' and 'selfassembly' crystal growth mechanisms are proposed to explain the formation of the heterostructures.

The MoO(2) nanorods (NRs) were synthesized by simple hydrogen reduction using the MoO(3) nanobelts (NBs) as the templates. The growth mechanism of one-dimensional (1D) MoO(2) nanostructure can be explained by the cleavage process due to the defects in the MoO(3) NBs. Different I/V characteristics of individual MoO(2) NRs were obtained at different bias voltages, which can be explained by Ohmic and Schottky conduction mechanisms, and the resistivity increased at high bias voltage probably because of the oxidation of MoO(2) NRs with large specific surface area.

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Typical microelectromechanical systems (MEMS) devices and packages are composed of micron-scaled structures. Experimental investigations on the effect of size on the deformation behavior of simple structures have shown that the deformation behavior of metals and polymers is size dependent. The size dependence in small structures is attributed to the contribution of nonnegligible strain gradients. In this work, torsion and bending of micron-sized rods and plates were analyzed by using a two-parameter model of strain-gradient plasticity. Microrod torsion and microplate bending experimental data were analyzed to determine the magnitude of the strain-gradient material parameters. The parametric analyses showed that conventional analysis is applicable only when the size of the structure is significantly larger than the material parameters, which are typically in the micron range. Strain-gradient analysis of micron-sized rod revealed that the presence of strain gradient increased the torque by three to nine times at the same twist. For MEMS structures with micron-sized features, conventional structural analysis without strain gradient is potentially inadequate, and strain-gradient analysis must be conducted to determine the elastoplastic behavior in the micron scale.

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