Centerline detection and line width estimation are important for many computer vision applications, e.g., road network extraction from high resolution remotely sensed imagery. Radon transform-based linear feature detection has many advantages over other approaches: for example, its robustness in noisy images. However, it usually fails to detect the centerline of a thick line due to the peak selection problem. In this paper, several key issues that affect the centerline detection using the radon transform are investigated. A mean filter is proposed to locate the true peak in the radon image and a profile analysis technique is used to further refine the line parameters. The theta-boundary problem of the radon transform is also discussed and the erroneous line parameters are corrected. Intensive experiments have shown that the proposed methodology is effective in finding the centerline and estimating the line width of thick lines.

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The proportion of new energy power generation gets higher and higher, due to the depletion of fossil energy resources. However, new energy power is generally unstable, so that it is necessary to use energy storage batteries to balance the power peak and valley. Although lithium-ion batteries have been widely used in various fields, in particular for large-scale energy storage, the low abundance of lithium in the earth crust makes it untenable to meet the ever-intense future demand. Sodium ion batteries, which have similar energy storage mechanism to lithium-ion batteries, have attracted significant attentions due to their abundant raw material resources, low cost, and fairly high energy densities. Layered transition metal oxides are a class of the most promising cathode materials for sodium ion batteries, owing to their high theoretical specific capacities, good conductivity, and fast diffusion kinetics. In this paper, we conduct a comprehensive review of the electrochemical performance, structural characteristics, performance shortcomings and modification technologies about the O3- and P2-type layered transition metal oxide cathode materials. The application potentials of layered materials are summarized and analyzed, which provides a reference for the industry to select the most promising and practical layered cathode material for sodium ion batteries.

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Soil fumigation is an important agronomic practice in the production of many high-value vegetable and fruit crops, but the use of chemical fumigants can lead to excessive atmospheric emissions. A large-scale (2.9 ha) field experiment was conducted to obtain volatilization and cumulative emission rates for two commonly used soil fumigants under typical agronomic practices: 1,3-dichloropropene (1,3-D) and chloropicrin. The aerodynamic method and the indirect back-calculation method using ISCST3 and CALPUFF dispersion models were used to estimate flux loss from the treated field. Over the course of the experiment, the daily peak volatilization rates ranged from 12 to 30 μg m(-2) s(-1) for 1,3-D and from 0.7 to 2.6 μg m(-2) s(-1) for chloropicrin. Depending on the method used for quantification, total emissions of 1,3-D and chloropicrin, respectively, ranged from 16 to 35% and from 0.3 to 1.3% of the applied fumigant. A soil incubation study showed that the low volatilization rates measured for chloropicrin were due to particularly high soil degradation rates observed at this field site. Understanding and quantifying fumigant emissions from agricultural soil will help in developing best management practices to reduce emission losses, reducing adverse impacts to human and ecosystem health, and providing inputs for conducting risk assessments.