Language and language education are central to studies of Chinese diasporic culture. However, existing scholarship has overwhelmingly focused on how overseas Chinese populations navigate language politics in their host societies. This research adopts a different perspective by examining the crucial roles overseas Chinese played in establishing Indonesian language programs in mainland China between the mid-1940s and mid-1960s. Specifically, overseas Chinese “returnees” were indispensable in founding the National College of Oriental Studies during World War II and launching several Indonesian language programs in the early years of the People’s Republic of China. While these programs served vastly different political purposes over time, they also reveal critical yet often overlooked aspects of—and surprising continuities in—China-Indonesia cultural exchange amid decolonization, domestic conflicts, and the Cold War. Although the primary aim of these programs was to fulfill the operational needs of state agencies and government-affiliated organizations, returnee networks played essential roles in promoting Indonesian culture in China. They actively participated in circulatory cultural diplomacy between the two countries, contributing significantly to China’s long-term knowledge production on Indonesia.
Under acidic pH conditions, the mobility of Cr is controlled by (Fe, Cr)(OH)3 coprecipitation in solution (homogeneous) and on soils (heterogeneous), and natural organic matter (NOM) adsorption onto soils could affect heterogeneous (Fe, Cr)(OH)3 precipitation on soils and, thus, Cr transport. Here, Suwannee River NOM (SRNOM) adsorption onto Al2O3 was investigated under varied carbon concentrations, and properties of SRNOM-coated surfaces were characterized using spectroscopic and interfacial techniques. Heterogeneous (Fe, Cr)(OH)3 precipitation on SRNOM-coated surfaces was studied at acidic pH via metal analysis and phase/size characterization. With lower NOM concentrations, preferential adsorption of aromatic moieties occurred, rendering more hydrophobic surfaces, which promoted nucleation and resulted in precipitates with higher Cr/Fe ratios. With higher NOM concentrations, NOM-coated surfaces became more negatively charged, attributed to enrichment of acidic (i.e., carboxylate) structures. Therefore, the amount of heterogeneous precipitates increased as enriched carboxylates and negative charge promoted heterogeneous nucleation and deposition. The controlling mechanisms were further validated with model OMs: For humic acid and fulvic acid, similar phenomena were observed with SRNOM. For polyacrylic acid with high acidity and no aromaticity, its adsorption onto Al2O3 made the surface highly negatively charged and hydrophilic, resulting in promoted heterogeneous precipitation with low Cr incorporation. Preferential adsorption of OMs with higher molecular weights (MWs) onto Al2O3 also occurred, but the MW did not affect either the amount or composition of heterogeneous (Fe, Cr)(OH)3 precipitates. The new knowledge learnt here could help in understanding Cr immobilization under acidic environments with diversified NOMs.
Nickel (Ni) is a biologically active metal whose reactivity and isotope fractionation in the marine realm are strongly influenced by biological and redox-related processes, giving the stable isotope system potential for studying past ocean environments. Reducing, organic-rich, sediments constitute an important sink of Ni from the modern ocean. Importantly, at open ocean upwelling margins, these kinds of sediment record the isotope composition of the modern deep ocean. Thus, records of their Ni isotope composition in the past have the potential to record the past deep ocean isotope composition and the oceanic isotope mass balance. However, the detailed processes controlling the upwelling sink are not fully understood. Here, we address this issue through data for sediments, porewaters and the water column of Kiel Bight in the Western Baltic Sea. This setting preserves sediments that have similar characteristics to those of open ocean upwelling margins, allowing us to study specific controlling processes in a well constrained setting. In common with sediments from open-ocean upwelling settings, Ni is well-correlated with carbon in solid sediment, suggesting delivery of Ni via rain of organic carbon from the water column. Overall, porewaters at all sites studied show increasing Ni concentrations from around 10 nM near the sediment–water interface to as high as 50 nM at 25 cm depth. This increase is correlated with increases in ammonia concentrations, suggesting release of Ni from anaerobic respiration of organic matter. However, porewater Ni/NH4 ratios are always lower than Ni:N of water column suspended particulate matter, suggesting an additional process that removes Ni from the porewater. Porewater sulphide also increases with depth, from as low as zero at the sediment–water interface to levels as high as 3 mM at 25 cm. Overall, porewater Ni isotopes become heavier with depth, from bottom water δ60Ni around +0.5 to +1‰, to values as high as +2.3‰ at depth. All these observations strongly suggest that Ni is removed from porewater into a solid sulphide. Mass balance indicates that over 90% of the Ni delivered in organic material to the sediment–water interface is transferred from organic matter into solid sulphide. Upward diffusive fluxes lead to the loss of a small amount back to the water column via a benthic flux. Given the large proportion of Ni retained within the sediment, the loss of such Ni does not strongly impact the isotope composition of the buried pool. These data are crucial in clarifying the processes controlling the size and isotope composition of organic-rich sediments on upwelling margins.
Effective risk assessment and control of environmental antibiotic resistance depend on comprehensive information about antibiotic resistance genes (ARGs) and their microbial hosts. Advances in sequencing technologies and bioinformatics have enabled the identification of ARG hosts using metagenome-assembled contigs and genomes. However, these approaches often suffer from information loss and require extensive computational resources. Here we introduce a bioinformatic strategy that identifies ARG hosts by prescreening ARG-like reads (ALRs) directly from total metagenomic datasets. This ALR-based method offers several advantages: (1) it enables the detection of low-abundance ARG hosts with higher accuracy in complex environments; (2) it establishes a direct relationship between the abundance of ARGs and their hosts; and (3) it reduces computation time by approximately 44–96% compared to strategies relying on assembled contigs and genomes. We applied our ALR-based strategy alongside two traditional methods to investigate a typical human-impacted environment. The results were consistent across all methods, revealing that ARGs are predominantly carried by Gammaproteobacteria and Bacilli, and their distribution patterns may indicate the impact of wastewater discharge on coastal resistome. Our strategy provides rapid and accurate identification of antibiotic-resistant bacteria, offering valuable insights for the high-throughput surveillance of environmental antibiotic resistance. This study further expands our knowledge of ARG-related risk management in future.
Salt crystallization within micro-fractures poses a significant challenge in shale gas production by impeding gas diffusion. This study investigates the real-time behavior of gas flow-induced salt crystallization within a visualized micro-fracture network. Observations reveal that salt crystals initially propagate along the fracture surface before exhibiting perpendicular growth. Crystal nucleation during the saturation stage occurs within a few seconds, while subsequent growth in the supersaturated stage takes approximately 15–20 s. Gas flow drives the evaporation of immobile water, leading to salt precipitation. Furthermore, increasing gas flow rate and decreasing solution salinity are found to accelerate crystal growth. To mitigate plugging damage caused by salt crystallization, controlling pressure differences and solution salinity is crucial.