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We report on the experimental observation of passive harmonic mode locking of bunches of single-pulse solitons or twin-pulse solitons in an Erbium-doped fiber ring laser. Experimental investigations on the phenomenon revealed that, although the soliton interaction between the adjacent single-/twin-pulse solitons in a bunch is weaker than that of the pulse interaction in the twin-pulse solitons, a soliton bunch could also function as a unit and form the state of passively harmonic mode-locking. Harmonic mode-locking is one of the intrinsic characteristics of soliton emission in passively mode-locked fiber ring lasers. It can be formed based on the single-pulse soliton, twin-pulse soliton, or bunch of solitons. [ABSTRACT FROM AUTHOR]

The conductance of the CeO2 nanowire film is found to decrease by about two orders of magnitude in air under ultraviolet illumination. Such a drastic decrease in conductance is attributed to light-induced desorption of H2O from the nanowire’s surface. When exposed in air, the surface conductivity of the nanowire increases significantly due to the adsorption of H2O. Considering the large surface-to-volume ratio of the nanowire, the conductance of the nanowire film is mainly controlled by surface conduction. Upon ultraviolet illumination, desorption of H2O results in the decrease of the conductance of the nanowire film, thus leading to the anomalous photoconductivity. [ABSTRACT FROM AUTHOR]

Room-temperature oxygen sensing is realized from individual ZnS nanobelts. Under UV illumination the current through ZnS nanobelt increases from 0.265 to 2.26 nA as the oxygen pressure decreases from 1×105 to 3×10-3 Pa. The conductance of ZnS nanobelt exhibits a logarithmic dependence on oxygen pressure, which is in agreement with theoretical prediction. The sensing is based on the enhanced modulation of ZnS nanobelts conductance by adsorbed oxygen under illumination. These results demonstrate an approach to in situ precisely detect oxygen at room temperature. [ABSTRACT FROM AUTHOR]

Two kinds of In2O3 nanowires (NWs), i.e., straight and tapered ones, are grown from 20-nm-thick Au/300-nm-thick In and 20-nm-thick Au/1-μm-thick In films on glass at 400 °C by a one-step annealing method, respectively. All the NWs are single crystalline. The growth of the NWs is initiated by Au catalyst particles via vapor-liquid-solid growth mechanism, and an additional side growth might be responsible for the nonuniform diameters of the tapered NWs. It is revealed that a certain content of oxygen in the In film facilitates the large-scale growth of the In2O3 NWs. The field-emission studies show that the In2O3 NWs on glass have a low turn-on electric field of about 4.3 V/μm. Our growth method has potential applications in the in situ fabrication and integration of the In2O3 NWs-based devices, especially with glass as substrates. [ABSTRACT FROM AUTHOR]

We observe an anomalous electrorheological (ER) behavior of suspensions composed of ZnO nanowires and silicone oil. In contrast to the usual ER behavior, a decrease in viscosity of the suspensions is observed. Such an anomalous behavior results from the migration of ZnO nanowires to the electrodes under a dc electric field. The migration leads to a relatively pure silicone oil zone between the electrodes, as confirmed by optical microscope observations. The occurrence of the electrophoresis is proposed as the origin of the decrease in shear stress. [ABSTRACT FROM AUTHOR]