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We consider the interaction of gravitational fields (including "gravitoelectromagnetism") with interstellar matter dealing with resonant wave-particle and wave-wave interactions on the basis of magnetic-type Maxwell-Vlasov equations. It is found that the behavior of the perturbed GEM fields, the perturbed density and self-generated gravitomagnetic field with very low frequency, can be described by the nonlinear coupling Eqs. (98)- (100). Numerical results show that they may collapse. In other words, due to self-focusing, a stronger GEM fields magnified up to 10 3 times, could be produced; they are the GEM cavitons, describing gravity shielding and filament effects. And the self-generated gravitomagnetic field is concurrently focused by the background material to a small space where it may be detected.

The morphology of nano-titania has a significant effect on the photoelectric properties of dye-sensitized solar cells. In this study, microsphere assembly of a TiO2 mesoporous nanosheet constructed by nanocuboids was conducted via a simple hydrothermal process. The XRD pattern indicated that the hierarchical mesoporous microspheres are anatase phase with decreased (004) peaks. Raman spectrum shows enhanced Eg peaks at 143 and 638 cm(-1) caused by the symmetric stretching vibration of O-Ti-O of the (101) crystalline facet in anatase TiO2. FESEM and TEM images show that well monodispersed TiO2 microspheres with a diameter of 2 μm are assembled by TiO2 mesoporous nanosheets with exposed (101) facets. The oriented attachment of TiO2 nanocuboids along the (101) direction leads to the formation of mesoporous titania nanosheets. The UV-Vis spectrum shows that the mesoporous TiO2 nanosheets have high scattering ability and light absorption by dye. Quasi-solid-state dye-sensitized solar cells that incorporate these microspheres into the top scattering layers exhibit a prominent improvement in the power conversion efficiency of 7.51%, which shows a 45.8% increase in the overall conversion efficiency when compared with the spine hierarchical TiO2 microspheres (5.15%). There is the potential application for microsphere assembly of mesoporous TiO2 nanosheets in quasi-solid-state dye-sensitized solar cells with excellent stability.