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Elastic and water stable macroaggregate are significant to soil structure. which is the base of the soil, to maintain sustainable agriculture. Whether and how functional amendment fertilizer is capable of construction of the macroaggregate is the main purpose of the study. Scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) were used to investigate the effect of dolomite-based functional soil amendment fertilizers on soil structure. The fertilizers are beneficial to elastic-stable and water-stable aggregate construction. Calcined dolomite based soil amendment functional fertilizer (CDFF) was favorable to water-stable aggregates. The elastic-stable macroaggregate increased with lime, uncalcined dolomite based soil amendment functional fertilizer (UCDFF) and CDFF, and it was 3.0 to 4.2 times the microaggregate. The water-stable one of the CDFF was increased by 20.0%. The mean weight diameter (MWD) of the CDFF and the UCDFF increased by 0.05~0.19 mm, while that of lime only increased by 0.05 mm. The percentage of aggregate dispersion (PAD) of the CDFF was the least. SEM and EDS images revealed that Fe, Al, Si, Ca, Mg, C and O existed on the aggregates. The construction of stable aggregate lies in that the functional fertilizers can gradually neutralize soil H+ and prevent soil colloid dispersion. Soil particles are bounded together to construct micro-agglomerates and then macro-agglomerates through Ca2+, Mg2+ bond bridge and CaCO3, MgCO3 salt bridge and adhesion of SiO2, Fe2O3, Al2O3 as well as the other amorphous substances from the functional fertilizers.

Cr(VI) is a common wastewater pollutant. Various adsorbents including carbon-based materials are used for the removal of Cr(VI) owing to their high adsorption capacity. Chemical activation is an effective method to increase the specific surface area of adsorbents and, thus, further improve their adsorption capacity. However, research on the adsorption and removal of Cr(VI) from aqueous solutions by chemically activated carbon spheres is limited. Here, glucose and sodium dodecylbenzene sulfonate were used to produce carbon spheres (CSs) via hydrothermal synthesis. Activated carbon spheres (ACSs) were then derived using KOH. The adsorption of Cr(VI) in solution by CS and ACS was investigated through batch experiments. The results indicate that the specific surface area of the ACS was 1491.21 m2 g−1, which was much higher than that of the CS. The adsorption kinetics of the sorbent was consistent with the pseudo-second-order kinetic model and the adsorption isotherm followed the Langmuir model. This indicated that the adsorption process of the ACS with respect to Cr(VI) was mainly via single molecular layer adsorption and chemisorption. In a 200 mg L−1 Cr(VI) solution, the maximum amount of Cr(VI) adsorbed by the ACS was 230.15 mg g−1, and some of these adsorbed Cr(VI) were reduced to Cr(III). These results show that ACSs have strong potential for application in the removal of Cr(VI) from aqueous solutions.

Nutrient channel release mechanism of bio-oil polymer coated controlled-release fertilizer (BCRF) was revealed. The bio-oil polymer was developed by co-polymerization of castor oil and epoxy soybean oil for the preparation the coating layer of the BCRF. Scanning electron microscopy (SEM) technology was introduced to investigate the channels in the coating layer of the BCRF and their effect on the nutrient release. Three types of channels affected the nutrient release rate of BCRF. The longevity of the BCRF increased due to decreasing nutrient release channels as the dosage of the bio-oil polymer increased. The number, length and tortuosity of the channels were decisive for the nutrient release rate of BCRF, while moisture, temperature and coating technology were sufficient factors. Higher the ratio of bio-oil polymer resulted in an increasing number and the cross-sectional area of channels in the coating layer. The dosage and ratio of the bio-oil polymer had no effect on the surface structure of the BCRF before culture. The small channel was 48.9 times that of the large channels, but cross-section area of the large channels was 79.9 times that of small channels. The large channels played a decisive role in controlling nutrient release rate of BCRF. The quantitative information of BCRF nutrient release rate depended on adjusting the amount of coating material, the ratio of bio-oil polymer in the material, coating technology and channel-forming agents. When the ratio of bio-oil polymer to polyisocyanate was 5:4–5:5 and the amount of coating material was at least 3 % of the weight of the core fertilizer, the BCRF exhibited excellent controlled release performance. The experiment will help the production of environmentally friendly controlled-release fertilizers through the application of bio-oils to adjust nutrient release performance and reduce fertilizer pollution in agricultural production.

Biochar is considered a promising material for sequestering CO2 from the atmosphere, thus helping to alleviate climate change when returned to the soil. Biochar stability is the most decisive factor determining its C sequestration potential. Mineral modification may improve biochar characteristics, but systematic research on the effect of mineral modification on the C retention and stability of biochar and the associated mechanisms is limited. Therefore, in this study, rice straw was used to produce biochar at various temperatures (300, 400, 500, 600, and 700 °C), with vermiculite as a modified mineral material. Several methods including thermogravimetric analysis, Fourier transform infrared (FTIR) spectroscopy, X-ray photoelectron spectroscopy (XPS), and nuclear magnetic resonance (NMR) spectroscopy were used to evaluate the effect of vermiculite modification and carbonization temperature on biochar stability. Biochar yield and C retention ratio decreased with increasing temperatures but increased by 13.5–38.8% and 5.2–22.1%, respectively, after vermiculite modification. The ratios of C thermal weight loss, atomic H/C, and C oxidation loss in the biochar were reduced with increasing carbonization temperature, indicating improved thermal, aromatization, and chemical oxidation stability. A trade-off that did not compromise C sequestration potential was optimized at 700 and 600 °C for the unmodified and modified biochar, respectively. Furthermore, the total mineral content of the biochar, particularly Fe, Al, Mg, and Si, were increased by vermiculite modification. FTIR results showed that chemical bonds, such as Si–O–C and Fe–O, were formed or enhanced on the biochar surface after vermiculite modification. This was further certified by the XPS survey spectra. NMR results indicated that biochar stability was enhanced by increasing the aromatization rate during carbonization, that is, by the conversion of C from alkyl and carbonyl C to aromatic C. This study provides a basis for research into and the development of functional biochar and its application in C sequestration.

The extraction of relevant lip features is of continuing interest in the speech domain. Using end-to-end feature extraction can produce good results, but at the cost of the results being difficult for humans to comprehend and relate to. We present a new, lightweight feature extraction approach, motivated by glimpse based psychological research into racial barcodes. This allows for 3D geometric features to be produced using Gabor based image patches. This new approach can successfully extract lip features with a minimum of processing, with parameters that can be quickly adapted and used for detailed analysis, and with preliminary results showing successful feature extraction from a range of different speakers. These features can be generated online without the need for trained models, and are also robust and can recover from errors, making them suitable for real world speech analysis.