The self-diffraction effect was used to improve temporal contrast of femtosecond pulse by about four-order of magnitudes. This self-diffraction effect was also used to measure a 55fs pulse based on the self-referenced...
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10-fs deep-ultraviolet pulses are generated by broadband four-wave mixing and with a pulse compressor consisting of prisms and gratings. Pulse distortion in an ultrafast spectroscopic setup can be compensated by the c...
Hierarchically organized γ-AlOOH hollow spheres with nanoflake-like porous surface textures were fabricated by chemically induced self-transformation of metastable solid particles of amorphous aluminium oxyhydroxide ...
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Hierarchically organized γ-AlOOH hollow spheres with nanoflake-like porous surface textures were fabricated by chemically induced self-transformation of metastable solid particles of amorphous aluminium oxyhydroxide produced in situ within hydrothermal reaction mixtures containing aluminium sulfate and urea. Thermal treatment of the γ-AlOOH product at 600 °C produced intact hollow spheres of γ-Al 2 O 3 . Formation of the hollow γ-AlOOH structures was strongly dependent on the reaction temperature and time, as well as the concentration and molar ratio of the reactants. Hollow γ-AlOOH spheres were not obtained using mixtures of urea and aluminium nitrate or aluminium chloride, as metastable precursor particles were not produced under these conditions. In general, the described method is efficient and environmentally benign, and has significant advantages over traditional template approaches to the large-scale production of hollow inorganic materials. The prepared hierarchically organized γ-AlOOH and γ-Al 2 O 3 hollow spheres should have important applications in areas of catalysis, separation science, biomedical engineering and nanotechnology.
A novel multi-mode model suitable for semiconductor ring lasers with ultra short optical pulse injection including all nonlinear coupling components is established and used to explore multilongitudinal-mode dynamics. ...
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In this paper, by taking into account the coupling of the ionization of ablation gas and atmosphere, an electrons density distribution model is built. Using this model, the transmission properties of different polariz...
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In this paper, by taking into account the coupling of the ionization of ablation gas and atmosphere, an electrons density distribution model is built. Using this model, the transmission properties of different polarization radar wave through sheath are evaluated on the basis of the transmission matrix theory. Then, we discuss the effects of the electrons density, the added magnetic field, and the radar wave frequency on the transmission properties. As a result of this investigation, greater transmission power could be gained in order to efficiently shorten communication blackout, by reducing the electrons density or choosing proper added magnetic field and the frequency of the radar wave according to the different polarization form of the radar wave.
In this paper,by taking into account the coupling of the ionization of ablation gas and atmosphere,an electrons density distribution model is built. Using this model,the transmission properties of different polarizati...
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In this paper,by taking into account the coupling of the ionization of ablation gas and atmosphere,an electrons density distribution model is built. Using this model,the transmission properties of different polarization radar wave through sheath are evaluated on the basis of the transmission matrix theory. Then,we discuss the effects of the electrons density,the added magnetic field,and the radar wave frequency on the transmission properties. As a result of this investigation,greater transmission power could be gained in order to efficiently shorten communication blackout,by reducing the electrons density or choosing proper added magnetic field and the frequency of the radar wave according to the different polarization form of the radar wave.
The performance of candidate protocols for first-generation Ku-band very small aperture terminal (VSAT) satellite networks is compared. The goal is to assist the process of selecting a protocol. The performance compar...
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The performance of candidate protocols for first-generation Ku-band very small aperture terminal (VSAT) satellite networks is compared. The goal is to assist the process of selecting a protocol. The performance comparison is carried out over a range of possible traffic, channel and satellite parameters, leading to an understanding of the appropriate regime for each of the protocols under consideration. The protocols considered are unslotted Aloha, slotted Aloha, selective-reject (SRE) Aloha, and demand-assigned time-division multiple-access (TDMA) or DAMA.< >
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