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Neighboring relationships among plants have been extensively reported, but little is known about the effect of waterlogging. In this study, Cleistocalyx operculatus (Roxb.) Merr. and Dalbergia odorifera T. Chen saplings were used in investigating the neighboring relationships between legumes and non-leguminous woody plants under different planting and watering regimes. Results showed that C. operculatus and D. odorifera are waterlogging-tolerant species, and C. operculatus with high proportion of adventitious roots would be at an advantage during waterlogging. The growth performance of D. odorifera was better than that of C. operculatus under well-watered single-planting conditions. However, under well-watered mixed-planting conditions, C. operculatus had an obvious inhibitory effect on the growth traits (increments in stem height and leaf number, total leaf area, and total plant fresh weight) and physiological responses (net photosynthesis rate, stomatal conductance, and transpiration) of D. odorifera, whereas the growth of C. operculatus slightly increased in the presence of D. odorifera. Under waterlogging mixed-planting conditions, the facilitative effect was more intensive; the total leaf area, underground fresh weight, and total plant fresh weight of C. operculatus significantly increased, but a negative effect was found in D. odorifer. These results showed that the neighboring relationship between these two species is predominantly favorable to C. operculatus. This research sheds new light on screening waterlogging-tolerant arbor species and species collocation during vegetation restoration and reconstruction activities in wetland systems.

Based on the 2012 and 2018 China Family Panel Studies (CFPS) data, this paper explores the influence mechanism between rural social security, precautionary savings, and the upgrading of rural residents’ consumption structure in China from theoretical and empirical perspectives. The results show that China’s rural social security can significantly promote the upgrading of rural residents’ consumption structure, and 1.79% of the positive effect of China’s rural social security on the upgrading of rural residents’ consumption structure in China is realized through the mediating effect of precautionary saving; the robustness of the regression results is tested by a placebo test and substitution matching method. Through further research, it is found that the promotion effect of China’s rural social security on the upgrading of rural residents’ consumption structure in China varies by region and age. In order to promote the sustainable upgrading of rural residents’ consumption structure, rural social security policies should be further improved, and new rural social pension insurance policies should be formulated according to local conditions, which will ultimately promote the economic development of rural areas.

Based on the Peking University Digital Financial Inclusion Index and 2011–2018 provincial panel data, this paper discusses the mechanism of digital financial inclusion on agricultural green total factor productivity from both theoretical and empirical perspectives. The result shows that digital financial inclusion can significantly increase China’s agricultural green total factor productivity, and the optimization of the agricultural industry structure can bring a significant “structural growth effect”. A total of 8.42% of the positive effects of digital financial inclusion on agricultural green total factor productivity are realized through the intermediary effect of agricultural industrial structure optimization. Through further research, it is found that digital financial inclusion has regional heterogeneity in the improvement of agricultural green total factor productivity. At the same time, digital financial inclusion of different dimensions will also have a differential impact on the improvement of agricultural green total factor productivity. In order to promote the green development of agriculture, it is necessary to further improve the financial development environment, optimize the structure of the agricultural industry, and formulate development policies for digital inclusive finance in accordance with local conditions.

The self-assembly behaviors of sodium oleate (NaOL), dodecylamine (DDA), and their mixtures in aqueous solution were systematically investigated by large-scale molecular dynamics simulations, respectively. The interaction mechanisms between the surfactants, as well as the surfactants and solvent, were revealed via the radial distribution function (RDF), cluster size, solvent-accessible surface area (SASA), hydrogen bond, and non-bond interaction energy. Results showed that the molecules more easily formed aggregates in mixed systems compared to pure systems, indicating higher surface activity. The SASA values of DDA and NaOL decreased significantly after mixing, indicating a tighter aggregation of the mixed surfactants. The RDF results indicated that DDA and NaOL strongly interacted with each other, especially in the mixed system with a 1:1 molar ratio. Compared to van der Waals interactions, electrostatic interactions between the surfactant molecules were the main contributors to the improved aggregation in the mixed systems. Besides, hydrogen bonds were found between NaOL and DDA in the mixed systems. Therefore, the aggregates in the mixed systems were much more compact in comparison with pure systems, which contributed to the reduction of the repulsive force between same molecules. These findings indicated that the mixed NaOL/DDA surfactants had a great potential in application of mineral flotation.

In this paper, a novel collector, dodecyl dimethyl betaine (BS-12), was used in the selective separation of ilmenite from titanaugite. The flotation performance and associated adsorption mechanism were studied by micro-flotation experiments, particle size analysis, Fourier-transform infrared (FT-IR) spectroscopy analysis, and X-ray photoelectron spectroscopy (XPS) analysis. The micro-flotation results indicated that BS-12 exhibited a stronger collecting ability towards ilmenite than titanaugite within an acidic pH range, and that the recovery of ilmenite was about 50% higher than that of titanaugite under the optimum flotation conditions. Particle size analysis demonstrated that BS-12 could selectively agglomerate ilmenite to a certain extent and then contribute to the flotation difference between ilmenite and titanaugite. FT-IR results showed some characteristic bands of BS-12 on treated ilmenite, and on titanaugite with BS-12. The XPS analysis further confirmed that BS-12 chemisorbed onto ilmenite and titanaugite in a similar way, but the limited active sites on titanaugite in comparison with ilmenite accounted for their differences in flotation.

A scientific and rigorous study on the adsorption behavior and molecular mechanism of collector sodium oleate (NaOL) on a Ca2+-activated hydroxylated &alpha, quartz surface was performed through experiments and density functional theory (DFT) simulations. The rarely reported hydroxylation behaviors of water molecules on the &alpha, quartz (101) surface were first innovatively and systematically studied by DFT calculations. Both experimental and computational results consistently demonstrated that the adsorbed calcium species onto the hydroxylated structure can significantly enhance the adsorption of oleate ions, resulting in a higher quartz recovery. The calculated adsorption energies confirmed that the adsorbed hydrated Ca2+ in the form of Ca(H2O)3(OH)+ can greatly promote the adsorption of OL&minus, on hydroxylated quartz (101). In addition, Mulliken population analysis together with electron density difference analysis intuitively illustrated the process of electron transfer and the Ca-bridge phenomenon between the hydroxylated surface and OL&minus, ions. This work may offer new insights into the interaction mechanisms existing among oxidized minerals, aqueous medium, and flotation reagents.

The separation of sylvite (KCl) and halite (NaCl), two main minerals in potash ores, is difficult because of the high ion concentration, fine particles of NaCl, and aggregation of KCl and NaCl in the saturated system. This study employed ammonium chloride (NH4Cl) as a new depressant and dodecyl morpholine as a collector in the reverse flotation process. The depressing mechanisms were studied by adsorption capacity experiments, infrared spectral analysis, and molecular dynamics simulations. The flotation tests showed that NaCl recovery increased to 97% after the addition of NH4Cl, while KCl recovery was reduced to &lt, 1%. Notably, NH4Cl not only acted as a selective KCl depressant, but also activated NaCl flotation. The FTIR measurements showed that NH4Cl was physically adsorbed onto the KCl and NaCl surfaces. Adsorption capacity experiments and molecular dynamics simulations confirmed more favorable NH4Cl adsorption on the KCl surface than on the NaCl surface. Moreover, the KCl mineral surface was more hydrophilic, while that of NaCl was more hydrophobic. Relative concentration analysis revealed that &gt, 90% ammonium and chloride ions were distributed 2&ndash, 10 &Aring, away from the KCl surface but were dispersed on the NaCl surface, indicating that NH4Cl exhibited stronger intermolecular interactions with KCl than with NaCl.

Novel collector lead(II)-benzohydroxamic acid (Pb(II)&ndash, BHA) complexes in aqueous solution were characterized by using experimental approaches, including Ultraviolet-visible (UV-Vis) spectroscopy and electrospray ionization-mass spectrometry (ESI-MS), as well as first-principle density functional theory (DFT) calculations with consideration for solvation effects. The Job plot delineated that a single coordinated Pb(BHA)+ should be formed first, and that the higher coordination number complexes can be formed subsequently. Moreover, the Pb(II)&ndash, BHA species can aggregate with each other to form complicated structures, such as Pb(BHA)2 or highly complicated complexes. ESI-MS results validated the existence of Pb-(BHA)n=1,2 under different solution pH values. Further, the first-principles calculations suggested that Pb(BHA)+ should be the most stable structure, and the Pb atom in Pb(BHA)+ will act as an active site to attack nucleophiles. These findings are meaningful to further illustrate the adsorption mechanism of Pb(II)&ndash, BHA complexes, and are helpful for developing new reagents in mineral processing.

Cassiterite is the most common and important tin-bearing mineral, and calcite, a primary gangue mineral is generally found in tin deposit. The flotation separation of cassiterite from calcite remains a challenge due to their similar response to traditional reagents. In cassiterite flotation, sodium oleate (NaOL) and sodium silicate (SS) have been widely used as a collector and a depressant, respectively. However, the low selectivity of NaOL and the large amount of SS required (which leads to serious problems in wastewater treatment) remain a difficult issue. In this study, a novel reagent scheme using lead nitrate as the activator, salicylhydroxamic acid (SHA) as the collector and carboxymethyl cellulose as the depressant was employed to improve the separation selectivity of cassiterite from calcite. Results of the flotation experiment using this new reagent scheme showed that compared with the previously reported scheme using benzohydroxamic acid (BHA) as the collector, the separation of cassiterite from calcite exhibited a higher selectivity and selectivity index (SI). The mechanism of the selective separation was investigated by zeta potential measurements, Fourier transform infrared and X-ray photoelectron spectroscopy analysis.

Novel collector lead(II)-benzohydroxamic acid (Pb [II]-BHA) complexes in aqueous solution were characterized by using experimental approaches, including Fourier-transform infrared spectroscopy (FTIR), powder X-ray diffraction spectroscopy (PXRD), Ultraviolet-visible (UV-Vis) spectroscopy, and electrospray ionization–mass spectrometry (ESI-MS), and first-principle density functional theory (DFT) calculations with consideration of solvation effects. The Job plot delineated that a single coordinated Pb(BHA)+ should be formed first, and the binary structures of Pb(BHA)2 can be formed subsequently. Moreover, the Pb(II)-BHA species aggregated with each other to form highly complicated structures. ESI-MS results validated the existence of Pb-(BHA)n=1,2. The well-consistent infrared spectra from the DFT calculations and FTIR measurements indicated that the cis-amide (Za)-type BHA conformer may be dominant in the solid-state crystals of BHA. The first-principle calculations suggested that Pb(BHA)2 should be the most stable structure, and the Pb atom in Pb(BHA)+ will play as an active site to attack nucleophiles. These findings are meaningful to further illustrate the adsorption mechanism of Pb(II)-BHA complexes in mineral processing.

Tajikistan has abundant copper–tin resources. In this study, mineralogical analysis of copper–tin ores from the Mushiston deposit of Tajikistan indicates that tin mainly occurred in mushistonite, cassiterite, and stannite, while copper mainly occurred in mushistonite, malachite, azurite, and stannite. The total grades of tin (Sn) and copper (Cu) were 0.65% and 0.66%, respectively, and the dissemination size of copper–tin minerals ranged from 4 μm to over 200 μm. Coarse particles of copper–tin minerals were partially recovered by shaking table concentrators with a low recovery rate. Based on the mineralogical analysis, flotation recovery was used for the first time on the fine particles of copper–tin minerals, including mushistonite, from shaking table tailings. Single factor flotation experiments, open circuit flotation tests, and closed circuit flotation tests were performed to determine the optimized flotation conditions. Results indicated that benzohydroxamic acid (C6H5CONHOH) and lead nitrate could effectively recover the mushistonite, cooperating with other depressants. The final concentrate contained 13.28% Sn, with a recovery rate of 61.56%, and 18.51% Cu, with a recovery rate of 86.52%. This method proved effective for the exploitation and use of this type of copper–tin resource in Tajikistan.