Modelling the Accessibility Classification of Railway Lines: A case study of Northeast China railway network

A major problem addressed in railway network planning relates to distinguishing the role of the railway line in the network, and making a reasonable classification of the lines based on their role. Accessibility has been widely used to measure the role of transportation infrastructure in various studies, but few quantitative models for the classification of the role have been presented yet. In this paper, the line accessibility classification model is proposed, which aims to distinguish the role of railway lines in the network and to classify the lines into different grades. The practicability of the model is demonstrated through the case study of Northeast China railway network where the railway lines in Northeast China can be classified into three grades. The line accessibility classification model is supposed to be a strategic decision support tool for planners and policy makers to determine the classification of railway lines.</p

MAXI J1659-152 has likely returned back into quiescence

We report our most recent Swift observations of the black hole candidate MAXI J1659-152. After the observed re-brightening in May (ATels #3298, #3339, #3379), the source steadily decreased in luminosity. Our recent three observations taken on 07-15 (~1.3 ks), 07-17 (~0.9 ks), and 07-19 (~1.2 ks) show that the source intensity has dropped significantly, indicating that the source might be quiescent again

A Review of Vacuum Degradation Research and the Experimental Outgassing Research of the Core Material- Pu foam on Vacuum Insulation Panels

AbstractVacuum Insulation Panels(VIPs) have been regarded as a super thermal insulation material with a thermal resistance of about 5-8 times higher than that of equally thick conventional polyurethane boards. In this paper, the researches on factors influencing interior pressure in VIPs, including gas and water vapor permeation through the barrier and outgassing of the core materials, were reviewed respectively. Following this, aiming at the outgassing from open cell PU foam, the specific outgassing rate of the core material is tested not only at room temperature but also at low and high temperatures by an orifice known-conductance method