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A novel 2D MOF Tb-DBA was constructed. Tb-DBA could detect Al3+, Cr3+ and Fe3+ ions rapidly, sensitively, selectively, reversibly and visually. Tb-DBA represents a promising material for the quick detection of metal ions in aqueous solution.

TRIM is a recommended command to deliver data invalidation information of the file system to flash storage. It is issued on both system level and device level. Since it can reduce the number of data copies during device-level garbage collection (DGC), TRIM has been widely used to improve the endurance and performance of mobile devices. Contrary to the common belief, this work identifies that the default TRIM scheme has both merit and drawback to the performance of mobile devices, especially in flash-friendly file system (F2FS), which is a commonly used file system in mobile devices. On one hand, TRIM can reduce garbage collection migration to prolong the flash lifetime as well as improving I/O throughput; On the other hand, TRIM may induce I/O contentions. This article proposes a new TRIM scheme, iTRIM, to distribute the timing overheads to system idle time. To further reduce I/O contention and improve I/O performance, the design of iTRIM considers the TRIM size, and the logical addresses’ pattern of victim invalidated data. Experimental results show that iTRIM can minimize I/O contentions while retaining the benefits of the default TRIM scheme for endurance and performance.

This article explores how to optimize the freshness of real-time data for energy harvesting (EH)-based networked embedded systems (NESs) with energy constraints. We introduce the concept of age of information (AoI) to quantitatively measure the data freshness and present a comprehensive analysis on the average AoI of the real-time data with stochastic update arrival and energy replenishment patterns for single-source EH-based systems. An optimal offline solution and an effective online solution are designed to select a sequence of real-time data updates (while discarding the remaining ones) and determine their corresponding transmission time to minimize the average AoI. We further extend these findings to multisource EH-based NESs, and present an optimal offline solution and an efficient online solution to schedule updates for each data source to optimize the average AoI. The correctness of the analysis and the effectiveness of the proposed solutions have been validated through extensive experiments by comparing to the state-of-the-art methods. According to the experimental results, the proposed solutions reduce the average AoI by 47.2% and 69.1% on average comparing to the state-of-the-art solutions for single-source and multisource EH-based NESs, respectively, with low harvesting rates.

Rural homestead transfer is of considerable significance for the revitalization of rural land assets and sustainable use of land resources. “Amphibious” farmers are the most likely to transfer their homestead. As such, it is important to study their transfer behavior and influencing factors to promote homestead transfer. The study involved distributing questionnaires to 768 “amphibious” farmers in Guangdong Province, China, and 747 samples were valid. The impact of the farmers’ citizenship ability and homestead utility preference on their homestead transfer behavior was analyzed using a binary logistic model. The study found that: (1) the citizenship ability of “amphibious” farmers had a significant positive impact on their willingness; the stronger the citizenship ability was, the stronger the willingness to transfer homesteads was. (2) Property and the guarantee utility of the homestead have an opposite impact on the willingness of “amphibious” farmers to transfer their homestead; if the property utility of the homestead is strong, its transfer intention is strong, but if the guarantee effect is strong, its transfer intention is weak. If the amphibious farmers are older, more educated, and have longer working years in cities, their willingness to transfer homestead will be lower. (3) The “amphibious” farmers working in cities and towns were found to have a stronger willingness to transfer homestead than those working in rural areas. Hence, the government should formulate differentiated policies for homestead transfer according to the ability endowment of farmers, improve various urban services and security infrastructure based on the urban housing of “amphibious” farmers, weaken the security utility of their rural homestead to flexibly realize their homestead property value, help them become citizens, and promote homestead transfer.