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The coefficients of oil and water transfer resistance in porous media are the basis of numerical study on the migration of contamination in the pipeline, soil cleaning, oilfield water flooding, and oilfield water treatment. Based on the quartet structure generation set, the porous media with random distribution are constructed. The lattice Boltzmann method is used to simulate the mesoscopic migration of oil and water in porous media. Then the distribution law of oil and water velocity and pressure in porous media is analyzed, and the fitting equations of oil and water resistance coefficients are obtained under different porosity. The results show that when the oil and water migrate in porous media, the viscous resistance coefficient is larger than the inertia resistance factor, and the viscosity resistance coefficient of water is obviously higher than that of oil, while the coefficient of inertia resistance of oil and water is nearly same.

Gliomas are aggressive type of brain tumors and cause significant human mortality world over. The frequent relapses, development of drug resistance, the adverse effects of the chemotherapy and dearth of the therapeutic targets form the major hurdles in glioma treatment. Several studies suggest that microRNAs (miRs) are involved in the development and progression of different cancers. Herein, the therapeutic potential of miR-181 was explored in human glioma cells. The results showed that miR-181 is significantly downregulated in human glioma cells. Overexpression of miR-181 caused significant inhibition in the proliferation of U87 and U118 glioma cells. The miR-181 triggered growth inhibition was found to be mainly due to the induction of apoptosis which was concomitant with increase in the Bax/Bcl-2 ratio. Additionally, miR-181 enhanced the chemosensitivity of the glioma cells to temozolomide and suppressed their invasion. Bioinformatic analysis showed that miR-181 exerts its effects by inhibiting the expression of Selenoprotein K (SELK). The expression of SELK was found to be significantly upregulated in glioma cells and silencing of SELK suppressed the proliferation of glioma cells. Nonetheless, overexpression of SELK could nullify the effects of miR-181 on the proliferation of the glioma cells. Taken together, miR-181 may exhibit therapeutic implications in the treatment of glioma.

Based on the Fokker-Planck equation, a theoretical computational model is established to describe the change with time of the energy distribution of conduction electrons in a dielectric material under the irradiation of short laser pulses. Using this model, the evolution of electron density in a dielectric material (taking SiO2 glass as an example) is calculated; with the critical plasma density damage criterion, the material damage thresholds are determined for various laser wavelengths and pulse durations. For laser wavelengths of 1 060, 800 and 532 nm, the obtained damage threshold curves of SiO2 are rather close to each other. The role of impact ionization and photoionization in material damage is also investigated. It is found that when the laser pulse duration is greater than 1 ps, i

This paper presents a new technique for high resolution direction finding that only requires the array outputs to be sampled one at a time by a single channel receiver. According to single channel output, we establish a new processing model. The new model is structurally similar to the conventional multiple channel model and the only difference is that the rectification item can be modified. This allows the application of most existing high resolution DOA estimation algorithms of multiple channel in a single channel model. The feasibility of this approach is demonstrated with simulation.

In this paper, a new Bayesian array signal model structure based on signal reconstruction is proposed, that allows us to define a posterior distribution on the parameter space, which is applicable to both wideband and narrowband signals. Unfortunately, a direct evaluation of this distribution and of its features, including posterior model probabilities, requires evaluation of some complicated high-dimensional integrals. We develop an efficient hybrid sampling algorithm based on reversible jump Markov Chain Monte Carlo methods to jointly detect and estimate the sources impinging on a single array of sensors in Gaussian noise. This algorithm provides higher resolution than traditional wideband methods. The accuracy of the structure and the validity of this method are well verified by the simulation.

Narrowband antennas are not suitable for UWB systems. This paper emphasizes on the design for mono-cone and sphere-loaded mono-cone antennas. The voltage standing wave ratio (VWSR), input impedance, fidelity coefficient of radiated pulse, radiant efficiency and radiant patterns are computer calculated. Simulated results confirm that the mono-cone and sphere-loaded mono-cone antennas be of good ultra-wide band performance. Sphere-loaded mono-cone antennas are better to radiate ultra-wide band pulses than mono-cone antennas on condition of the same size of antennas.

A novel maximum likelihood estimation model for time delay is constructed to estimate the passive time delay; the signal of emitter is unknown in this model. According to the model characteristics, the fast Fourier transformation (FFT) method is used to achieve time delay estimation (TDE). In order to improve the accuracy of estimator, the Markov Chain Monte Carlo (MCMC) sampling method is used to estimate the time delay value directly. Unlike traditional algorithms, MCMC method can obtain time delay without peak detection. Furthermore, the Cramer-Rao lower bound (CRLB) of this model is derived. Finally, simulations show that the proposed approach is suitable for both narrowband and broadband TDE, and the MCMC algorithm can achieve more precise time delay value with the same sample, and it has lower computational complexity than IS algorithm. The novel approach can estimate also the time delay of non-integer multiple of the sampling interval.