Abstract: A method and a system for mental index prediction are provided. The method includes the following steps. A plurality of images of a subject person are obtained. A plurality of emotion tags of the subject person in the images are analyzed. A plurality of integrated emotion tags in a plurality of predetermined time periods are calculated according to the emotion tags respectively corresponding to the images. A plurality of preferred features are determined according to the integrated emotion tags. A mental index prediction model is established according to the preferred features to predict a mental index according to the emotional index prediction model.

Abstract: A voltage tracking circuit is provided. The voltage tracking circuit includes first and second P-type transistors and a control circuit. The drain of the first P-type transistor is coupled to a first voltage terminal. The gate and the drain of the second P-type transistor are respectively coupled to the first voltage terminal and a second voltage terminal. The control circuit is coupled to the first and second voltage terminals and generates a control voltage according to the first voltage and the second voltage. The sources of the first and second P-type transistors are coupled to an output terminal of the voltage tracking circuit, and the output voltage is generated at the output terminal. In response to the second voltage being higher than the first voltage, the control circuit generates the control signal to turn off the first P-type transistor.

Abstract: Disclosed herein are methods for treating an exhaust stream comprising NOx, the methods comprising receiving an exhaust stream and combining it with at least one nitrogen-containing reagent to form a combined stream, heating the combined stream to a reaction temperature ranging from about 870° C. to about 1100° C. to react at least a portion of the nitrogen-containing component, cooling the reacted stream in a first cooling step to a first temperature, and optionally further cooling the reacted stream in a second cooling step to a second temperature, wherein the first cooling step comprises heat exchange between at least a portion of the exhaust stream and at least a portion of the reacted stream. Exhaust treatment systems are also disclosed herein.

Abstract: Disclosed herein are methods for treating an exhaust stream comprising NOx, the methods comprising receiving an exhaust stream and combining it with at least one nitrogen-containing reagent to form a combined stream, heating the combined stream to a reaction temperature ranging from about 870° C. to about 1100° C. to react at least a portion of the nitrogen-containing component, cooling the reacted stream in a first cooling step to a first temperature, and optionally further cooling the reacted stream in a second cooling step to a second temperature, wherein the first cooling step comprises heat exchange between at least a portion of the exhaust stream and at least a portion of the reacted stream. Exhaust treatment systems are also disclosed herein.