Here we present a useful ammonia (NH 3 ) gas sensor based on reduced graphene oxide (RGO)polyaniline (PANI) hybrids. PANI nanoparticles were successfully anchored on the surface of RGO sheets by using RGO-MnO 2 hybrids as both of the templates and oxidants for aniline monomer during the process of polymerization. The resultant RGO-PANI hybrids were characterized by transmittance electron microscopy, infrared spectroscopy, Raman spectroscopy, UV-Vis spectroscopy, and scanning electron microscopy. The NH 3 gas sensing performance of the hybrids was also investigated and compared with those of the sensors based on bare PANI nanofibers and bare RGO sheets. It was revealed that the synergetic behavior between both of the candidates allowed excellent sensitivity and selectivity to NH 3 gas. The RGO-PANI hybrid device exhibited much better (3.4 and 10.4 times, respectively, with the concentration of NH 3 gas at 50 ppm) response to NH 3 gas than those of the bare PANI nanofiber sensor and bare graphene device. The combination of the RGO sheets and PANI nanoparticles facilitated the enhancement of the sensing properties of the final hybrids, and pave a new avenue for the application of RGO-PANI hybrids in the gas sensing field.

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We use local polynomial fitting to estimate the nonparametric M-regression function for strongly mixing stationary processes {(Y i , X i )}. We establish a strong uniform consistency rate for the Bahadur representation of estimators of the regression function and its derivatives. These results are fundamental for statistical inference and for applications that involve plugging in such estimators into other functionals where some control over higher order terms are required. We apply our results to the estimation of an additive M-regression model.

A novel hybrid material composed of single-walled carbon nanotubes (SWNTs) and cobalt phthalocyanine (CoPc) derivatives have been obtained. The resultant hybrid has been confirmed by infrared spectroscopy, Raman spectroscopy, UV-Vis spectroscopy and X-ray photoelectron spectrometry. The results revealed that the CoPc derivatives had been successfully anchored on the surface of nanotubes through p-p stacking. The quantitatively determination of the CoPc derivatives have also been carried out through characterization by thermogravimetric analysis. Furthermore, the morphology of the resultant SWNT-CoPc derivative hybrids has been observed by transmission electron microscopy and scanning electron microscopy. Finally, gas sensor tests were performed to check the potential of this hybrid material while the sensing devices have been fabricated. The synergetic behavior between both of the candidates allows an excellent sensitivity and selectivity to dimethyl methylphosphonate (DMMP) (stimulant of nerve agent sarin). Overall, we present the advantages of combining metallophthalocyanine (MPc) with SWNTs in enhancing the properties of the final product, and pave a new avenue for the application of SWNT-MPc hybrids in the gas sensing field.

A simple ultrasonic nanowelding technique has been developed to reliably bond single-wall carbon nanotubes (SWCNTs) onto metal electrodes, by pressing SWCNTs against electrodes under a vibrating force at ultrasonic frequency. The bonds formed have been demonstrated to be mechanically robust. Using this technique, a stable low-Ohmic contact between SWCNTs and metal electrodes was achieved, with resistances in the range of 8-24 k for a 1 µm long metallic SWCNT at room temperature. The performance of carbon nanotube field-effect transistors (FETs) fabricated using this ultrasonic nanowelding method has also been greatly improved. Transconductance as high as 3.6 µS among the solid-state back-gate individual nanotube FETs has been achieved.