The carbonized PAF-1 derivatives formed by high-temperature KOH activation showed a unique bimodal microporous structure located at 0.6 nm and 1.2 nm and high surface area. These robust micropores were confirmed by nitrogen sorption experiment and high-resolution transmission electron microscopy (TEM). Carbon dioxide, methane and hydrogen sorption experiments indicated that these novel porous carbon materials have significant gas sorption abilities in both low-pressure and high-pressure environments. Moreover the methane storage ability of K-PAF-1-750 is among the best at 35 bars, and its low-pressure gas adsorption abilities are also comparable to the best porous materials in the world. Combined with excellent physicochemical stability, these materials are very promising for industrial applications such as carbon dioxide capture and high-density clean energy storage.

Among currently available optical spectroscopic methods, Raman spectroscopy has versatile application to investigation of dynamical processes of molecules leading to chemical changes in the gas and liquid phases. However, it is still a challenge to realize an ideal standoff coherent Raman spectrometer with which both high temporal resolution and high-frequency resolution can be achieved, so that one can remotely probe chemical species in real time with high temporal resolution while monitoring the populations in their respective rovibronic levels in the frequency domain with sufficiently high spectral resolution. In the present study, we construct an air-laser-based Raman spectrometer, in which near-infrared femtosecond (fs) laser pulses at 800 nm and cavity-free picosecond N2+ air-laser pulses at 391 nm generated by the filamentation induced by the fs laser pulses are simultaneously used, enabling us to generate a hybrid ps/fs laser source at a desired standoff position for standoff surveillance of chemical and biochemical species. With this prototype Raman spectrometer, we demonstrate that the temporal evolution of the electronic, vibrational, and rotational states of N2+ and the coupling processes of the rovibrational wave packet of N2 molecules can be probed.

Piezoelectric effect was first used for disinfection. In this process, hydrothermally synthesized nano/micrometer tetragonal-BaTiO3 was selected as the piezo-catalyst which was stressed by ultrasound to generate piezoelectric potential. It was found that the inactivation number of the nano/micrometer tetragonal BaTiO3 exposure or sonication alone within 180 min was 0.30 log and 0.70 log for E. coli in deionized water, respectively, while addition of 2 g tetragonal-BaTiO3 with piezo-activity in the ultrasound system resulted in a 2.72 log inactivation without the input of any additional energy, only by original ultrasound. The latter was 2.72 folds as great as the sum of the two former inactivation numbers. However, addition of cubic-BaTiO3 without piezo-activity only led to a 1.02 log inactivation. And moreover, in the process of serious physical damage and chemical oxidation of cells, substantial leakages of intracellular materials were observed. These great differences not only clearly indicated that the combination of sonication and piezocatalysis possessed a great inactivation potential but also suggested that there was a significant synergistic inactivation effect between piezocatalytic oxidation and sono-mechanical destruction.

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Piezoelectric polymers are increasingly considered as favorable materials for microactuator applications due to their fast response, low operating voltages and greater efficiencies of operation. However, the difficulty of forming structures and shapes has so far limited the range of mechanical design. In this work, the design and fabrication of a unimorph piezoelectric cantilever actuator using piezoelectric polymer polyvinylidene fluoride (PVDF) with an electroplated layer of nickel iron (permalloy) alloy is described. The modeling and simulation of the composite cantilever was performed using CoventorWare to optimize the design parameters in order to achieve large tip deflections. These simulation results indicated that the thicknesses of both the piezo and non-piezo layers of the composite cantilever affect the magnitude of deflection of the cantilever. It was shown that the tip deflection of such a cantilever with a length of 5 mm and a width of 1 mm can reach up to 70 µm, when simulation was carried out using a 28 µm thick PVDF layer at a non-piezo layer thickness of 5 µm. A PVDF polymer cantilever is fabricated using a simple punching technique based on microembossing. The permalloy layer was electroplated on one side of the PVDF to form a composite cantilever. The tip deflection of the cantilever was observed and measured under an optical microscope. The experimental results showed deflection values which are 20% less than those predicted by the simulation and analytical results. The thickness non-uniformity, residual stresses and possible difference in Young’s modulus values of the bulk material to that of electroplated permalloy film are identified as some of the potential issues that might have caused this difference.

The gamma unit is used to irradiate a target within the brain. During such a treatment many parameters, including the number of shots, the coordinates, the collimator size and the weight associated with each shot, affect the amount of dose delivered to the target volume and to the surrounding normal tissues. Hence it is not easy to determine an appropriate set of these parameters by a trial and error method. For this reason, we present here an optimization method to determine mathematically those parameters. This method is composed of two steps: firstly, a quasi-Newton method is used to deal with the continuous variables such as position and weight of shots; the result obtained at the end of this step then serves as the initial configuration for the next step, in which a simulated annealing method is applied to optimize all the aforementioned parameters. Application of the proposed methods to two examples shows that our optimization algorithm runs in a satisfactory way.