No abstract

Abstract-Fire safety education is essential to every student on campus. Fire safety knowledge learning and operational practice are both important. There is evidence that the virtual reality (VR) based educational method can be a novel and effective approach to learning and practice. However, the existing VR-based system for fire safety education has some shortcomings such as lack of interactivity and high equipment complexity, resulting in low practicability. In order to improve the effect of fire safety education on campus, this paper establishes the model and architecture of fire safety education system based on VR technology. The framework and various elements of fire safety education system are designed and implemented according to the combination of relevant fire safety education theory and VR technology. Finally the prototype version of fire safety education system based on VR technology is built on the HTC VIVE helmet equipment. Through the usability test and comparative analysis of the application experiment, the experiment results prove the feasibility and effectiveness of the proposed approach.

No abstract

No abstract

Determining the characteristics of pore-throat structures, including the space types present and the pore size distribution, is essential for the evaluation of reservoir quality in tight sandstones. In this study, the results of various testing methods, including scanning electron microscopy (SEM), pressure-controlled porosimetry (PCP) and rate-controlled porosimetry (RCP), were compared and integrated to characterize the pore size distribution and the effects of diagenesis upon it in tight sandstones from the Ordos Basin, China. The results showed that reservoir spaces in tight sandstones can be classified into those with three types of origins (compaction, dissolution, and clay-related) and that the sizes and shapes of pore space differ depending on origin. Considering the data obtained by mercury injection porosimetry and the overestimation of pore radii by pressure-controlled porosimetry, the full-range pore size distribution of tight sandstones can be determined by combining data from PCP with corrected RCP data. The pore-throat radii in tight sandstone vary from 36 nm to 200 μm, and the distribution curve is characterized by three peaks. The right peak remains similar across the sample set and corresponds to residual intergranular pores and dissolution pores. The middle and left peaks show variation between samples due to the heterogeneity and complexity of nano-scale throat bodies. The average micro-scale pore content is 33.49%, and nano-scale throats make up 66.54%. The nano-scale throat spaces thus dominate the reservoir space of the tight sandstones. Compaction, dissolution, carbonate cementation, and clay cementation have various effects on pore-throats. Compaction and carbonate cementation decrease pore body content. Pore-bridging clay cementation decreases throat space content. As pore-lining clay cementation preserves pore space.