Modern service industry agglomeration and its influencing factors: spatial interaction in Chinese cities

From the perspective of spatial interaction, the impact of the modern service industry’s agglomeration on today’s increasingly connected cities is worth studying. This study uses a spatial econometric model to test the development trends and factors influencing the modern service industry’s agglomeration in the Yangtze River Delta city group. The results show that the industry has the highest agglomeration in leasing and business and the lowest in education. The overall concentration of the industry is generally low, implying a more fragmented distribution. Moreover, the agglomeration has a significant positive spatial correlation with economic development, knowledge intensity, and city size. However, it has a negative correlation with information technology level and transportation infrastructure, inconsistent with existing research. This study argues that the development of the information technology level and transportation infrastructure in a city could lead to the ‘virtual agglomeration’ of the modern service industry and gradual decentralisation in geographical distribution. This is a new paradox that city groups may face when improving their infrastructure and developing modern services. This study uses the spatial interaction perspective to propose policy recommendations for promoting the modern service industry’s agglomeration and coordinated regional development

A Joint Replication-Migration-based Routing in Delay Tolerant Networks

Abstract—Delay tolerant networks (DTNs) use mobility-assisted routing, where nodes carry, store, and forward data to each other in order to overcome the intermittent connectivity and limited network capacity of this type of network. In this paper, we propose a routing protocol that includes two mechanisms: message replication and message migration. Each mechanism has two steps: message selection and node selection. In message repli-cation, we choose the smallest hop-count message to replicate. The hop-count threshold is used to control the replication speed. We propose a metric called 2-hop activity level to measure the relay node’s transmission capacity, which is used in node selection. Our protocol includes a novel message migration policy that is used to overcome the limited buffer space and bandwidth of DTN nodes. We validate our protocol via extensive simulation experiments; we use a combination of synthetic and real mobility traces. Index Terms—Buffer management, delay tolerant networks (DTNs), message migration, message replication, routing. I

Wettability controlling effects on the fluid occurrence and flow in shale gas reservoirs: Present problems and new sights

The wettability of shale is critical for the development of shale oil and gas reservoirs. Due to its complex composition, which includes organic materials and a number of different inorganic minerals, shale’s wettability may show high heterogeneity. This could significantly affect fluid occurrence and flow processes in various kinds of pores. Organic and inorganic pores may have varying capillary pressures. The methodologies to describe the capillary forces in these two varieties of pores are still lacking, though. Additionally, due to the strong capillary pressure that may prevent liquid water from entering organic pores, the mechanisms by which water and methane accumulate in inorganic pores and organic pores may differ. Therefore, the two-phase occurrence mechanisms in the various types of pores in shale continue to be difficult problems. Furthermore, because organic and inorganic pores differ in their capillary pressure and fluid occurrence, wettability can have a significant effect on relative permeability. Thus, wettability is a significant factor that impacts the exploration and development of shale gas reservoirs. The development of shale gas reservoirs could benefit significantly from a thorough understanding of wettability heterogeneity, capillary pressure, water-methane occurrence, and relative permeability.Document Type: Current minireviewCited as: Zhang, S., Wang, T., Gao, Z., Zhang, Y. Wettability controlling effects on the fluid occurrence and flow in shale gas reservoirs: Present problems and new sights. Capillarity, 2023, 9(2): 25-31. https://doi.org/10.46690/capi.2023.11.0