The intragranular‐porous ferroelectric ceramic was fabricated for the first time with carbon nanotubes as pore formers and the effects of intragranular pores on the ferroelectric and dielectric properties were investigated. It was found that compared with dense ceramic the introduction of a small amount of intragranular pores led to an enhanced remnant polarization, an improved bulk resistivity, higher dielectric breakdown strength, a lower dielectric constant, and thus an enhanced energy storage density by 20%. Plus, a shift of the Curie temperature of ceramics was found in intragranular‐porous ferroelectric ceramic and possible reasons for these effects were interpreted.

In this report, we investigated the rod size dependence of photoluminescence (PL) from vertically aligned indium nitride (InN) nanorod arrays grown on Si(111) substrates. Abnormal temperature dependence of the PL peak energy and the PL bandwidth was observed for InN nanorods with a critical diameter, which is of the same order of the surface electron accumulation layer (20 nm). Exceptionally large activation energy of the nanorods with the critical diameter implies that holes within these narrow nanorods need to surpass the band bending energy near the surface in order to recombine with electrons accumulated in the surface layer. #

It has been well recognized that the weld pool geometry plays a critical role in the welding process. In this study, a diode laser welding control system is established. The authors performed a series of open-loop experiments to investigate the interaction and the correlation among of the laser energy, the welding speed, and the weld pool geometry. A digital camera with a high speed shutter is equipped to take pictures of the weld pool in real time. Custom computer vision software and image processing programs are applied to acquire the surface width of the weld pool. Based on the experimental study, the authors propose an applicable method to identify a SISO nonlinear continuous model for the established diode laser welding process. The identified nonlinear model takes the reciprocal of the welding speed as the input and the surface width of the weld pool as the output. To validate the model, the authors conduct further experiments including step and PRTS (Pseudo-random Ternary Signal) responses. In addition, the authors simulate the nonlinear model with same inputs and check the data agreements between the simulated results and the experimental data. The validation results confirm the applicability of the proposed nonlinear identification method and show that the model can successfully predict the surface width of weld pool for later use.

Failure behavior of PZT 95/5 under direct current, pulsed electric field and shock compression is studied by experimental and theory analysis in this paper. The electrothermal coupled failure behavior is a key mode when the PZT 95/5 is subjected to direct current. But when the pulsed electric field is applied to the PZT 95/5, the resonance effect and the relation between energy and frequency have been considered, the vibrant energy shifts to high frequency and the possibility of electromechanical-coupled failure behavior is increased with decreasing the pulsed duration. When the pulsed duration is increased, the failure behavior transfers from mechanical coupled with electric failure to direct current mode step by step. The Failure behavior of PZT 95/5 under compression is complex that not only all of failure mechanism in static must be considered but also the microstructure’s evolvement under shock compression should be considered.

Current MEMS design methods do not fulfill the needs of emerging complex MEMS devices. In this paper, a systematic direct solid modeling approach for surface micromachined MEMS design is proposed. In this approach, practical model of a surface micromachined MEMS device, designed in a traditional CAD environment, is simplified firstly; after simplification, masks and process sequences are generated through solid-based mask synthesis; then local variation is used to refining the 3D layer model; finally masks and process sequences are verified in rough simulation and accurate simulation. The approach aims at enabling designers to focus on creative design activity in an intuitive mode.