No abstract

Alumina-doped Pt/WO3/ZrO2 catalysts were prepared using either a constant or variable pH method. The obtained catalyst samples were characterized using N2 adsorption, X-ray diffraction, ultraviolet-visible diffuse reflectance, CO chemisorption, X-ray photoelectron spectroscopy, 27 Al magic-angle spinning nuclear magnetic resonance, and infrared spectroscopy of adsorbed pyridine. Compared to the catalyst prepared using the variable pH method, the catalyst prepared using the constant pH method had a higher surface area and Pt dispersion. More Brönsted acid sites were generated in the presence of H2 on the latter catalyst, and this was responsible for its higher catalytic activity in n-heptane hydroisomerization. When the reaction temperature was 200 °C and the weight hourly space velocity of n-heptane was 0.9 h-1 , the Pt/WO3/Al2O3-ZrO2 catalyst prepared using the constant pH method gave 70.0% conversion of n-heptane, which was significantly greater than the conversion obtained using the corresponding catalyst prepared using the variable pH method (43.5%).

Polygala japonica Houtt. (Polygalaceae) is a perennial herbaceous plant widely distributed in south China. Here, we assembled and characterized the complete chloroplast (cp) genome of P. japonica using sequencing data. The complete cp genome of P. japonica was 165,439 bp in length, with a GC content of 36.7%. The complete cp genome shows a typical quadripartite structure with a pair of inverted repeats (IRs) of 36,786 bp, separated by a large single copy region (LSC) of 83,722 bp, and a small single copy region (SSC) of 8,145 bp. A total of 135 genes were annotated in the cp genome of P. japonica , consisting of 89 protein-coding genes, 8 rRNA genes, and 38 tRNA genes. The phylogenetic analysis showed P. japonica had a closer relationship with P. tenuifolia.

In this paper, a state monitoring system for the cable joints of the ring main unit is constructed based on the passive wireless temperature sensor. Considering the sensor packaging structure and housing material, a temperature sensor that can meet the monitoring requirements of the T-shaped insulating sheath of the cable joint is designed. Based on the thermal circuit method, the real temperature value of the internal cable joint is calculated by using the outer surface temperature of the T-shaped insulating sheath to provide more accurate data for monitoring and early warning. The background monitoring software of the monitoring system is designed to realize the temperature of the T-shaped cable joint in the ring network cabinet. Online monitoring and abnormal early warning facilitate the operation and maintenance personnel to take timely measures, which can effectively improve the operation and maintenance efficiency of the ring cabinet of the distribution network and ensure the reliability of power supply.

In this paper, aiming at the operation and maintenance of the internal cable joints of the ring main unit, the research on the operation and management technology of the ring main unit cable joints based on temperature sensors is carried out. Starting from the principle of temperature sensing technology for cable joints, an online temperature monitoring system for the cable joints of the ring network cabinet is developed during the operating cycle. Comprehensive consideration of factors such as seasons, ambient temperature and humidity, line load current, etc., to evaluate the operating status of the cable joint temperature data as the main basis. A simple and adjustable bracket suitable for the fixed installation of the non-contact temperature sensor of the ring main unit has been developed. A method of managing the cable joints of the ring main unit during the operating cycle is proposed to realize the effective evaluation of the cable joint status. It can greatly improve the accuracy of condition monitoring, and improve the efficiency and level of operation and maintenance.