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A facile and effective C–H functionalization strategy for the synthesis of 2-mercaptobenzothiazoles and 2-mercaptobenzoxazoles is described. 1,3-Propanedithiol was employed to convert benzothiazoles and benzoxazoles to the corresponding heteroarylthiols in the presence of potassium hydroxide and DMSO. This novel protocol is featured by direct C–H mercaptalization of heteroarenes and a simple reaction system.

A copper-catalyzed direct and effective synthesis of aryl thiols from aryl iodides using readily available Na2S·9H2O and 1,2-ethanedithiol was described. A variety of aryl thiols were readily obtained in yields of 76–99%. In this protocol, Na2S·9H2O was used as ultimate sulfur source, and 1,2-ethanedithiol functioned as an indispensable catalytic reagent.

Optical fiber current sensors are widely used in the online monitoring of a new generation power system because of their high electrical insulation, wide dynamic range, and strong anti-electromagnetic interference ability. Current sensors, based on fiber Bragg grating (FBG) and giant magnetostrictive material, have the advantages of high reliability of FBG and high magnetostrictive coefficient of giant magnetostrictive material, which can meet the monitoring requirements of digital power systems. However, giant magnetostrictive materials are expensive, fragile, and difficult to mold, so giant magnetostrictive composite materials have replaced giant magnetostrictive materials as the sensitive elements of sensors. High sensitivity, high precision, wide working range, low response time, and low-cost optical fiber current sensors based on magnetostrictive composites have become a research hotspot. In this paper, the working principle of the sensor, the structure of the sensor, and the improvement of magnetostrictive composite materials are mainly discussed. At the same time, this paper points out improvements for the sensor.

This paper presents the design, fabrication, and characterization of a compact current sensor based on magnetostrictive composites and resistance strain gauges. Firstly, we designed three kinds of current sensors with different structures, in which the shape of the giant magnetostrictive material (GMM) was cuboid, cylindrical, and semi-cylindrical. A set of finite element method (FEM) simulations were performed to qualitatively guide the design of three prototypes of the current sensor. It was determined that the most ideal shape of the GMM was semi-cylindrical. Secondly, Terfenol-D (TD) powder and epoxy resin were mixed to prepare magnetostrictive composites. In this paper, magnetostrictive composites with different particle size ranges and mass ratio were prepared and tested. The results show that the magnetostrictive composites had the best performance when the particle size range was 149&ndash, 500 &mu, m and the mass ratio of epoxy resin to TD powder was 1:5. Finally, this paper tested the performance of the sensor. The sensitivity, repeatability, and linear working range of the sensor reached 0.104 &mu, &epsilon, /A, 2.51%, and 100&ndash, 900 A respectively, when only 0.31 g of TD powder was employed. This means that current measurement with low cost, high sensitivity, and wide range was realized.