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Microstructure damage and evolution in 4H-SiC under He-ion implantation and post-annealing have been investigated by the combination of fourier transform infrared spectrometer (FTIR), Raman scattering spectroscopy and high resolution X-ray diffractometer (HRXRD). After implantation, the 4H-SiC specimen exhibits a heavy damage and some amorphous state appear. With increasing annealing temperature, to some extent recovery in damaged lattices was observed, as a result of the peaks of Raman and HRXRD regain their intensities. However, the reverse annealing behavior in damaged peaks was displayed after annealed at 973K. This reverse annealing effect was revealed to be due to the formation and the growth of He bubbles above 973K.

This paper proposed a location algorithm based on nodes distance difference, it gets the distance difference from the blind node to every beacon node by wireless communication module Rf grouping, then, makes use of the improved Trilateral positioning method to work out Node coordinates, so as to realize the node localization of long-distance range, precision controlled, low-cost, and to analyze the positioning performance. The simulation experiments shows this algorithm has high feasibility and positioning performance, and it is also a complement of WSN Positioning technology.

Traditional traffic signal timing theory default the number of vehicles through the stop line per unit time as traffic demand. The traditional traffic demand definition obviously cannot respond the real traffic demand when the intersection is oversaturated. The main objective of this paper includes the following contents: (1) to analyze the defects of the traditional traffic demand definition; (2) to strictly define the concept of traffic demand. To achieve the research objective, researchers propose the “traffic demand in cycle” definition: the summation of the standard vehicles queuing during the red light time and the standard vehicles reaching the effective demand region during the non-red light time. The new definition introduces the concept of “effective demand areas”, referring to the areas follow-up vehicles slow down affected by the vehicles that haven’t pass the stop line. The new definition developed in the study can be directly used by traffic engineers and managers to signal timing.