Gaussian mixture model (GMM) is easily affected by noise, and Markov random field (MRF) model can well describe the spatial characteristics. The combination of the two is suitable for image segmentation with noise, but MRF model is prone to over segmentation. To solve this problem, an improved image segmentation algorithm based on adaptive weight coefficient was proposed, which can segment cerebrospinal fluid, gray matter and white matter from magnetic resonance imaging (MRI). Firstly, the K?means algorithm was used to obtain the initial segmentation results, and the Expectation?Maximization (EM) algorithm was used to estimate the parameters of GMM, and then the joint probability energy function of the pixel gray level of the image was obtained. Then, the adaptive weight coefficient was obtained by using the gray value, posterior probability and Euclidean distance of the center pixel and the neighboring pixels of the MRF neighborhood system, and the prior probability energy function was obtained by MRF. Finally, the final image segmentation results were obtained by Bayesian criterion. Experimental results show that the algorithm has strong adaptability, can better overcome the impact of noise on image segmentation. Compared with similar algorithms, the proposed algorithm has higher segmentation accuracy for brain MR images with noise, and obtains better segmentation results.

This paper summarized the separation effects of different electrodialysis systems on lithium in Salt Lake, including single selective electrodialysis, ionic liquid membrane and bipolar membrane, among which ionic liquid membrane with a broad development prospect possesses the characteristics of high recognition of Li⁺, long?term stability under electrolysis and low energy consumption. Furthermore, the advantages, disadvantages and tendency of prospective development of different electrodialysis systems in lithium extraction from Salt Lake were analyzed, and the industrialization research on the application of electrodialysis systems for lithium extraction from Salt Lake was analyzed.

The 4WS rotor is a new type of internal mixer rotor, and the ratio of long and short edge length is one of the important geometrical structure design parameters. The flow fields in 4WS rotor internal mixer with ratio of long and short edge length, 2∶1, 3∶1 and 4∶1, were simulated by using the software POLYFLOW. Through particle tracing technology, the macroscopic mixing state of the three internal mixers was visualized and tracked.Using the flow field data, the typical evaluation parameters of dispersive mixing and distributed mixing were calculated, and the mixing efficiency of the fluids in three different rotor internal mixers was compared and analyzed, and the effect of ratio of long and short edge length on mixing characteristics of 4WS rotor mixer was explored. The results show that, compared with the 4WS rotor internal mixer with a length ratio of 3∶1 and 2∶1, the dispersing and distributed mixing ability of 4∶1 type rotor have been greatly improved.