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We studied the effects of rice straw biochar addition on the microbial diversity of a paddy soil under fertilizer reduction. The MiSeq high-throughput sequencing analysis technology was used to analyze the microbial diversity of the rhizosphere and bulk soil under different levels of fertilization application(100%, 90%, and 80% of the conventional fertilization) and rice straw biochar addition(1%). The results indicated that the microbial diversity of the rhizosphere was more abundant than that of the bulk soil. Proteobacteria was the dominant phylum of Gram-negative bacteria accounting for 34.85%~47.57%. Biochar addition could reduce the abundance of Proteobacteria in the bulk soil and promote it in the rhizosphere. However, the reduction of fertilizer had an opposite effect on the abundance of Proteobacteria, while the greater influence was evidenced with more fertilizer reduction. In addition, Acidobacteria accounted for 10.48%~19.42%, which had an opposite response to that of Proteobacteria. At the genus level, Unclassified Burkholderiaceae, Unclassified Subgroup 6, and Unclassified bacterium 126 accounted for a relatively high proportion or microorganisms in the rhizosphere and bulk soil. The results of the Canonical Correspondence Analysis(CCA) showed that the abundance of dominant bacteria was related to environmental factors such as sampling location, fertilizer treatment, and biochar addition. Our study showed that the different fertilizer reduction(80% or 90%) and rice straw biochar addition(1%) could influence the microbial diversity of the rhizosphere and bulk soil, which was closely related to sampling location, fertilizer reduction, and biochar addition.

We perform the finite-difference time-domain (FDTD) simulations and analyze a dual-beam-reflection phenomenon for a Gaussian beam illuminating a Kretschmann configuration composed of a lossless dielectric waveguide between a photonic-crystal-made prism and air. One reflection beam has a small positive shift and the other has a large negative shift in the dual-beam-reflection phenomenon. The FDTD shows that the specific phenomenon takes place just when the corresponding leaky surface mode supported in the Kretschmann configuration is excited. Field profile of the surface mode demonstrates a strong localized stationary field in the dielectric waveguide. We find that the maximum negative lateral shift is -23.23a, corresponding to 4.99 times of the incident wavelength, which is 1.1615 times of the beam waist.

The molecular first hyperpolarizabilities β and ultraviolet spectra of two-dimensional charge transfer (2DCT) substituted annulenes by employing MP2 and TD-DFT approach, respectively. It is found that these 2DCT molecules 2—6 possess larger β values and blue-shifted absorption spectra in comparison with 1DCT molecules 8 and 9. It is helpful to solve the nonlinearity-transparency trade-off. For 2DCT molecules 2—7, values of β depend on the band length alternation (BLA) and when the BLA increases, the values of β decrease. Moreover, there is not a relationship between β and HOMO-LUMO energy gap ΔEHL for 2DCT molecules. The maximum absorption wavelength λmax of 2DCT molecules originates from deeper energy level orbital transition than HOMO→LUMO transition.

Molecular dynamics simulation has been used to study the friction and structure mechanism of Langmuir-Blodgett films of hydrocarboxylic acid (C15H31COOH) deposited on the SiO2 substrates at different sliding velocities. The results show that, for a certain monolayer, the shear pressure between the monolayers increases when the sliding speed is below 60m/s and decreases when the sliding speed exceeds 60m/s. The molecular tilt angle decreases as the velocity increases. The molecular clusters formed in the monolayers by the hydrogen-bond caused the long shear periods, but there is no hydrogen-bond between the monolayers.

Phase synchronization(PS) and generalized synchronization(GS) of a chaotic oscillator driven by two chaotic signals is investigated. Anti-biased PS and biased GS in the presence of biased coupling are found, i.e., the response oscillator can be phase synchronized (generally synchronized) by the drive with a weaker (stronger) coupling rather than the stronger (weaker) driver. The mechanism for these behaviors are explored.

Based on the classical electrostatics theory, the model of dipole-dipole interaction in the aggregation of rod-like amphiphilic molecules in Langmuir-Blodgett(LB)films has been presented in the paper. The relations between LB films structure and spectral absorption peak were obtained by using this model. For Z-type films, the dependence of molecular aggregation state on the structure parameters, i.e. separation distance a, separation between two adjacent layers d, molecular orientation θ, and layer number g, were studied by applying our model. The theoretical results agree well with experimental data.