Fabrication and Characterization of VO_2 Thin Films by Direct Current Facing Targets Magnetron Sputtering and Low Temperature Oxidation

Low valence vanadium oxide(VO2-x) thin films were prepared on SiO2/Si substrates at room temperature by direct current facing targets reactive magnetron sputtering, and then proc- essed through rapid thermal annealing. The effects of the annealing on the structure and phase transition property of VO2 were discussed. X-ray photoelectron spectroscopy, X-ray diffraction tech- nique and Fourier transform infrared spectroscopy were employed to study the phase composition and structure of the thin films. The resistance-temperature property was measured. The results show that VO2 thin film is obtained after annealed at 320 ℃ for 3 h, its phase transition tempera- ture is 56 ℃, and the resistance changes by more than 2 orders. The vanadium oxide thin films are applicable in thermochromic smart windows, and the deposition and annealing process is compatible with micro electromechanical system process.

On fast estimation of direction of arrival for underwater acoustic target based on sparse Bayesian learning

The Direction of Arrival （DOA） estimation methods for underwater acoustic target using Temporally Multiple Sparse Bayesian Learning （TMSBL） as the reconstructing algorithm have the disadvantage of slow computing speed. To solve this problem, a fast underwater acoustic target direction of arrival estimation was proposed. Analyzing the model characteristics of block-sparse Bayesian learning framework for DOA estimation, an algorithm was proposed to obtain the value of core hyper-parameter through MacKay＇s fixed-point method to estimate the DOA. By this process, it will spend less time for computation and provide more superior recovery performance than TMSBL algorithm. Simulation results verified the feasibility and effectiveness of the proposed algorithm.

Experimental researches on underwater target scattering properties in non-incident direction

In the bistatic case, theoretical analysis and experimental researches on underwater acoustic scattering properties of some submarine model are made in this paper. When sourcet target and receiver have complicated triangular configuration, the relationships among target strength, incidence angle and bistatic angle are obtained. The validity of this theory is verified by theoretical calculations and tank experiments. The research results can be directly used in bistatic or multistatic underwater acoustic detection systems.

Regulatory network established by transcription factors transmits drought stress signals in plant

Plants are sessile organisms that evolve with a flexible signal transduction system in order to rapidly respond to environmental changes.Drought,a common abiotic stress,affects multiple plant developmental processes especially growth.In response to drought stress,an intricate hierarchical regulatory network is established in plant to survive from the extreme environment.The transcriptional regulation carried out by transcription factors(TFs)is the most important step for the establishment of the network.In this review,we summarized almost all the TFs that have been reported to participate in drought tolerance(DT)in plant.Totally 466 TFs from 86 plant species that mostly belong to 11 families are collected here.This demonstrates that TFs in these 11 families are the main transcriptional regulators of plant DT.The regulatory network is built by direct protein-protein interaction or mutual regulation of TFs.TFs receive upstream signals possibly via post-transcriptional regulation and output signals to downstream targets via direct binding to their promoters to regulate gene expression.