Fiber Bragg grating monitors for thermal and stress of the composite insulators in transmission lines

Running composite insulators are prone to failure due to their harsh surrounding work environment, which directly affects the safe operation of transmission lines. This paper puts forward the method of using fiber Bragg grating(FBG) as the monitors to parameters correlated with thermal and stress of the composite insulators in transmission lines at working status. Firstly, monitoring points are found out by the mechanical test on composite insulator samples. Secondly, based on the monitoring theory, this paper introduces the feasibility design frame of the composite insulator with FBG implanted in the rod and the online monitor system. At last, it describes applications of this monitor system in the field of transmission lines.

Comparison Study on Anode Materials of Lithium-Ion Battery Applied in Tibet

Lithium-ion battery is facing the capacity fade in cold area. It reports in this paper to improve the temperature-tolerance using the novel materials in the battery design. Mesophase carbon microspheres (MG11) composed of 2H + 3R graphite phase with more uniform size were used as anode material and a new binder (WRA268) was used. The tests results show that at 0°C, MG11 using conventional binder (styrene butadiene rubber, SBR) attains 66% of reversible capacity retention rate, and synthetic graphite (FSN-1) using WRA268 as binder attains 76.9% of reversible capacity retention rate, but it attains 34% for the FSN-1 using SBR as the binder. These results show that MG11-WRA268 is promising materials using for battery in cold areas such as Tibet.

Preparation of nitrogen doped clews-like carbon materials and their application as the electrode in supercapacitor

In this work, nitrogen doped clews-like carbon materials were successfully fabricated through hydrothermal polymerization method, followed by post treatment that integrated the carbonization,activation and post-nitrogen doping into one process. This preparation method can form particular hierarchical porous structure without using any sacrificial templates. The experimental results show that the nitrogen doped clews-like hierarchical porous carbon materials possess a relatively high specific surface area of 815 m^2/g with the nitrogen content of 10.58 at%. The electrochemical properties show that the resulting sample delivers 258 F/g at a 0.5 A/g and excellent capacity retention of 79% at 20 A/g. After conducting 10,000 charge-discharge cycles at 10 A/g, the capacitance retention of 98.3% is achieved.These intriguing results demonstrate that the obtained nitrogen doped clews-like carbon materials will be promising electrode materials for supercapacitor and other energy storage devices.

Electrical transport properties of focused ion beam lithography Au contacts on PbTiO_(3)nanorods

PbTiO_(3)nanorods with tetragonal phase were synthesized by hydrothermal method and heat treatment,and temperature-dependent electrical transport properties of individual PbTiO_(3)nanorod were investigated.The results show that the conductivities of PbTiO_(3)nanorods are gradually enhanced with temperature increasing from 77.4 to 295 K,and exhibit the typical nonlinear Ⅰ–Ⅴ char-acteristics.The barrier height between Au electrode and nanorod is reduced from 0.137 to 0.088 eV with increasing bias from 0.2 to 1 V.The corresponding values of thermal activation energies are 0.172 and 0.06 eV below the conduction band for 180–295 and 77.4–180 K,respectively.This semiconductor-like behavior may result from the larger number of surface defects or localized states in the amorphorized PbTiO_(3).