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The marine atmospheric corrosion behavior of 700L high-strength automotive beam steel exposed for 36 months was investigated by scanning electron microscopy, energy dispersive spectroscopy, X-ray diffraction, and electrochemical technology. The corrosion kinetics of 700L steel followed the exponential function: D = 4.85t1.23. The rust layers were mainly composited of γ-FeOOH, α-FeOOH, γ-Fe2O3, and Fe3O4, regardless of the exposure duration. With an extended exposure time, the porosity, cracking, and spalling of the rust layers increased, and the densification and thickness uniformity decreased. Electrochemical measurements displayed that the corrosion resistance of the rusted 700L steel gradually decreased with increasing exposure time. A good correlation was found between rust layer composition, microstructure, and corrosion resistance. [ABSTRACT FROM AUTHOR]

Boron is a naturally occurring trace chemical element. High concentrations of boron in nature can adversely affect biological systems and cause severe pollution to the ecological environment. We examined a method to effectively remove boron ions from water systems using sugarcane bagasse biochar from agricultural waste with NH3 nanobubbles (10% NH3 and 90% N2). We studied the effects of the boron solution concentration, pH, and adsorption time on the adsorption of boron by the modified biochar. At the same time, the possibility of using magnesium chloride and NH3 nanobubbles to enhance the adsorption capacity of the biochar was explored. The carbonization temperature of sugarcane bagasse was investigated using thermogravimetric analysis. It was characterized using XRD, SEM, and BET analysis. The boron adsorption results showed that, under alkaline conditions above pH 9, the adsorption capacity of the positively charged modified biochar was improved under the double-layer effect of magnesium ions and NH3 nanobubbles, because the boron existed in the form of negatively charged borate B(OH)4− anion groups. Moreover, cations on the NH3 nanobubble could adsorb the boron. When the NH3 nanobubbles with boron and the modified biochar with boron could coagulate each other, the boron was removed to a significant extent. Extended DLVO theory was adopted to model the interaction between the NH3 nanobubble and modified biochar. The boron adsorption capacity was 36 mg/g at room temperature according to a Langmuir adsorption isotherm. The adsorbed boron was investigated using FT-IR and XPS analysis. The ammonia could be removed using zeolite molecular sieves and heating. Boron in an aqueous solution can be removed via adsorption with modified biochar with NH3 nanobubbles and MgCl2 addition. [ABSTRACT FROM AUTHOR]

Utilizing time-series data from ship trajectories to forecast their subsequent movement is crucial for enhancing the safety within maritime traffic environments. The application of deep learning techniques, leveraging Automatic Identification System (AIS) data, has emerged as a pivotal area in maritime traffic studies. Within this domain, the precise forecasting of ship trajectories stands as a central challenge. In this study, we propose the multi-gated attention encoder decoder (MGAED) network, a model based on an encoder–decoder structure specialized for predicting ship trajectories in canals. The model employs a long short-term memory network (LSTM) as an encoder, combined with multiple Gated Recurrent Units (GRUs) and an attention mechanism for the decoder. Long-term dependencies in time-series data are captured through GRUs, while the attention mechanism is used to strengthen the model's ability to capture key information, and a soft threshold residual structure is introduced to handle sparse features, thus enhancing the model's generalization ability and robustness. The efficacy of our model is substantiated by an extensive evaluation against current deep learning benchmarks. Through comprehensive comparison experiments with existing deep learning methods, our model shows significant improvements in prediction accuracy, with an at least 9.63% reduction in the mean error (MAE) and an at least 20.0% reduction in the mean square error (MSE), providing a new solution to improve the accuracy and efficiency of ship trajectory prediction. [ABSTRACT FROM AUTHOR]

Tartaric-sulfuric acid anodic (TSA) films were prepared on the surface of the 2024 Al alloy. These films were sealed with cerium salts at 25 °C and 65 °C, hot water, and dichromate. The morphology and corrosion resistance of the anodic films were investigated using a field emission scanning electron microscope/energy-dispersive spectrometer, an electrochemical workstation, an acidic spot test, and an immersion test. The results indicated that the surface of the TSA film sealed with cerium salt at 65 °C had a slightly lower cerium content compared to the TSA film sealed at 25 °C. It was found that increasing the sealing temperature of cerium salt could enhance the corrosion resistance of the TSA film. After immersion in a 3.5 wt.% NaCl solution for 336 h, no obvious corrosion pits were observed on the surface of the TSA film sealed at 65 °C, whereas many larger corrosion pits appeared on the surface of the TSA film sealed at 25 °C. The improved corrosion resistance of the TSA film sealed at 65 °C could be attributed to the synergistic effect of cerium oxide deposition and the hydration reaction. The corrosion resistance of the TSA film sealed at 65 °C was significantly better than that of the film sealed with hot water, but it was still lower than that of the TSA film sealed with dichromate. [ABSTRACT FROM AUTHOR]

Safety is fundamental for the practical development and application of energetic materials. Three tricyclic energetic compounds, namely, 1,3-di(1H-tetrazol-5-yl)-1H-1,2,4-triazol-5-amine (ATDT), 5′-nitro-3-(1H-tetrazol-5-yl)-2′H-[1,3′-bi(1,2,4-triazol)]-5-amine (ATNT), and 1-(3,4-dinitro-1H-pyrazol-5-yl)-3-(1H-tetrazol-5-yl)-1H-1,2,4-triazol-5-amine (ATDNP), were effectively synthesized through a simple two-step synthetic route. The introduction of intramolecular hydrogen bonds resulted in excellent molecular planarity for the three new compounds. Additionally, they exhibit regular crystal packing, leading to numerous intermolecular hydrogen bonds and π–π interactions. Benefiting from planar tricyclic structural features, ATDT, ATNT, and ATDNP are insensitive (IS > 60 J, FS = 360 N) when exposed to external stimuli. Furthermore, ATNT (Td = 361.1 °C) and ATDNP (Td = 317.0 °C) exhibit high decomposition temperatures and satisfying detonation performance. The intermolecular hydrogen bonding that produced this planar tricyclic molecular structure serves as a model for the creation of innovative multiple heterocycle energetic materials with excellent stability. [ABSTRACT FROM AUTHOR]

2 at.% Cu + 2 at.% Ni were co-doped in ZnO nanoparticles by a simple hydrothermal method, and then the modified nanoparticles were compounded into Cu-Ni alloy coatings using an electroplating technique. The effects of the current density (15–45 mA/cm2) on the phase structure, surface morphology, thickness, microhardness, corrosion resistance, and photocatalytic properties of the coatings were investigated. The results show that the Cu-Ni-Zn0.96Ni0.02Cu0.02O nanocomposite coatings had the highest compactness and the best overall performance at a current density of 35 mA/cm2. At this point, the co-deposition rate reached its maximum, resulting in the deposition of more Zn0.96Ni0.02Cu0.02O nanoparticles in the coating. More nanoparticles were dispersed in the coating with a better particle strengthening effect, which resulted in a minimum crystallite size of 15.21 nm and a maximum microhardness of 558 HV. Moreover, the surface structure of the coatings became finer and denser. Therefore, the corrosion resistance was significantly improved with a corrosion current density of 2.21 × 10–3 mA/cm2, and the charge transfer resistance was up to 20.98 kΩ·cm2. The maximum decolorization rate of the rhodamine B solution was 24.08% under ultraviolet light irradiation for 5 h. The improvement in the comprehensive performance was mainly attributed to the greater concentration of Zn0.96Ni0.02Cu0.02O nanoparticles in the coating, which played the role of the particle-reinforced phase and reduced the microstructure defects. [ABSTRACT FROM AUTHOR]

The instability and volatility of iodine is high, however, effective iodine biocidal species can be readily stored in iodinated azoles and then be released upon decomposition or detonation. Iodine azoles with high iodine content and high thermal stability are highly desired. In this work, the strategy of methylene bridging with asymmetric structures of 3,4,5-triiodo-1-H-pyrazole (TIP), 2,4,5-triiodo-1H-imidazol (TIM), and tetraiodo-1H-pyrrole (TIPL) are proposed. Two highly stable fully iodinated methylene-bridged azole compounds 3,4,5-triiodo-1-((2,4,5-triiodo-1H-imidazol-1-yl)methyl)-1H-pyrazole (3) and 3,4,5-triiodo-1-((tetraiodo-1H-pyrrol-1-yl)methyl)-1H-pyrazole (4) were obtained with high iodine content and excellent thermal stability (iodine content: 84.27% for compound 3 and 86.48% for compound 4; Td: 3: 285 °C, 4: 260 °C). Furthermore, their composites with high-energy oxidant ammonium perchlorate (AP) were designed. The combustion behavior and thermal decomposition properties of the formulations were tested and evaluated. This work may open a new avenue to develop advanced energetic biocidal materials with well-balanced energetic and biocidal properties and versatile functionality. [ABSTRACT FROM AUTHOR]

Lithium recovery is imperative to accommodate the increase in lithium demand. Salt lake brine contains a large amount of lithium and is one of the most important sources of lithium metal. In this study, Li2CO3, MnO2, and TiO2 particles were mixed, and the precursor of a manganese–titanium mixed ion sieve (M-T-LIS) was prepared by a high-temperature solid-phase method. M-T-LISs were obtained by DL-malic acid pickling. The adsorption experiment results noted single-layer chemical adsorption and maximum lithium adsorption of 32.32 mg/g. From the Brunauer–Emmett–Teller and scanning electron microscopy results, the M-T-LIS provided adsorption sites after DL-malic acid pickling. In addition, X-ray photoelectron spectroscopy and Fourier transform infrared results showed the ion exchange mechanism of the M-T-LIS adsorption. From the results of the Li+ desorption experiment and recoverability experiment, DL-malic acid was used to desorb Li+ from the M-T-LIS with a desorption rate of more than 90%. During the fifth cycle, the Li+ adsorption capacity of the M-T-LIS was more than 20 mg/g (25.90 mg/g), and the recovery efficiency was higher than 80% (81.42%). According to the selectivity experiment, the M-T-LIS had good selectivity for Li+ (adsorption capacity of 25.85 mg/g in the artificial salt lake brine), which indicates its good application potential. [ABSTRACT FROM AUTHOR]

Three new compounds based on the combination of furoxan (1,2,5-oxadiazole N-oxide) and oxa-[5,5]bicyclic ring were synthesized. Among them, the nitro compound showed satisfactory detonation properties (Dv, 8565 m s−1; P, 31.9 GPa), which is comparable to the performance of RDX (a classic high-energy secondary explosive). Additionally, the introduction of the N-oxide moiety and oxidation of the amino group more effectively improved the oxygen balance and density (d, 1.81 g cm−3; OB%, +2.8%) of the compounds compared to furazan analogues. Combined with good density and oxygen balance as well as moderate sensitivity, this type of furoxan and oxa-[5,5]bicyclic structure will open up a platform for the synthesis and design of new high-energy materials. [ABSTRACT FROM AUTHOR]

Here, 2% Cu + 2% Ni co-doped ZnO nanoparticles were synthesized using the hydrothermal method and were used as particle reinforcements of Cu-Ni nanocomposite coatings prepared by electroplating technology. The effects of the added (Cu, Ni) co-doped ZnO nanoparticles (2–8 g/L) on the phase structure, surface morphology, thickness, microhardness, corrosion resistance, and photocatalytic properties of the coatings were investigated. The nanocomposite coatings have obvious diffraction peaks on the crystal planes of (111), (200), and (220), showing a wurtzite structure. The surface of the nanocomposite coatings is cauliflower-like, and becomes smoother and denser with the increase in the addition of nanoparticles. The grain size, thickness, microhardness, corrosion resistance, and photocatalytic properties of the nanocomposite coating reach a peak value when the added (Cu, Ni) co-doped ZnO nanoparticles are 6 g/L. At this concentration, the mean crystallite size of the coating reaches a minimum of 15.31 nm, and the deposition efficiency of the coating is the highest. The (Cu, Ni) co-doped ZnO nanoparticle reinforcement makes the microhardness reach up to 658 HV. The addition of nanoparticles significantly improves the corrosion resistance and photocatalytic properties of nanocomposite coatings. The minimum corrosion current density is 2.36 × 10−6 A/cm2, the maximum corrosion potential is −0.301 V, and the highest decolorization rate of Rhodamine B is 28.73% after UV irradiation for 5 h. [ABSTRACT FROM AUTHOR]

Gallium alloys are ideal base carriers for temperature-sensitive ferrofluids, which can be used for energy convection, soft robotics, microchannels, magnetorheological devices, etc. In this study, gallium was mixed with different substances (In, Sn, Zn, Ge, and Al) to obtain a low melting point, reduce the wetness and adhesion of its alloys, and realize low viscosity. The melting point, contact angle on certain solid plates, viscosity, and viscoelasticity of the gallium alloys were measured, and some useful gallium alloys were obtained. The experimental results showed that Ga80In10Sn10 had lower wettability at a larger contact angle of 148.6° on the Teflon plate. Here, (Ga80In10Sn10)97Zn3 with a melting point of 8.2 °C, lower than the melting point of Galinstan, was developed. It had a viscosity about three times that of water at room temperature and an elastic response from 0.1 to 100 Hz at a 1% strain amplitude for the viscoelasticity. It was expected that a kind of temperature-sensitive magnetic fluid with a gallium-based liquid alloy as the base carrier liquid would be prepared in the future with Teflon as the container to achieve energy conversion under the drive of the magnetic field. [ABSTRACT FROM AUTHOR]

Rare earth oxides such as La2O3 and Gd2O3 are abundant in waste optical glass. The separation of rare earth oxides is beneficial to the recycling of rare earth resources. In this study, the rare earth oxide Gd2O3 particles were separated from La2O3 particles using high gradient magnetic separation, and the influence of different fluid media (i.e., water, anhydrous ethanol, and their mixture) on the separation results was investigated. By using the measured zeta potential of oxide particles in water/ethanol of different pH and water with different dispersants (Na2SiO3 9H2O, citric acid, Na2CO3, and sodium hexametaphosphate), the DLVO (Derjaguin–Landau–Verwey–Overbeek) potential calculations and their analysis applied to high gradient magnetic separation results were also performed. The results showed that using anhydrous ethanol or adding a dispersant in water as a fluid medium can promote the separation of magnetic Gd2O3 particles under a high-gradient magnetic field. Among the different conditions, anhydrous ethanol can improve the grade of Gd2O3 to 95% from 70% with water. Furthermore, ethanol can be reused after filtration, making it an environmentally friendly fluid medium. Among the four dispersants, sodium hexametaphosphate, Na2SiO3, and Na2CO3 can also increase the separation rate of La2O3 and Gd2O3 to about 95%. The effect of citric acid on the separation performance is slightly worse, and the recovery rate of Gd2O3 is 80%. This study provides a new reference for selecting a fluid medium for magnetic separation. [ABSTRACT FROM AUTHOR]

As life becomes richer day by day, the requirement for quality industrial products is becoming greater and greater. Therefore, image anomaly detection on industrial products is of significant importance and has become a research hotspot. Industrial manufacturers are also gradually intellectualizing how product parts may have flaws and defects, and that industrial product image anomalies have characteristics such as category diversity, sample scarcity, and the uncertainty of change; thus, a higher requirement for image anomaly detection has arisen. For this reason, we proposed a method of industrial image anomaly detection that applies a generative adversarial network based on attention feature fusion. For the purpose of capturing richer image channel features, we added attention feature fusion based on an encoder and decoder, and through skip-connection, this performs the feature fusion for the encode and decode vectors in the same dimension. During training, we used random cut-paste image augmentation, which improved the diversity of the datasets. We displayed the results of a wide experiment, which was based on the public industrial detection MVTec dataset. The experiment illustrated that the method we proposed has a higher level AUC and the overall result was increased by 4.1%. Finally, we realized the pixel level anomaly localization of the industrial dataset, which illustrates the feasibility and effectiveness of this method [ABSTRACT FROM AUTHOR]

Activated carbon has been used to treat organic dyes in water systems; however, the adsorption capacity of the samples studied was limited by the specific surface area and influenced by the pH of the aqueous solution. In this study, a hybrid adsorbent consisting of a mixture (MCS) of activated chestnut shell biochar (CN) and pyrolyzed snail shell material (SS) was developed to solve this problem, with the waste snail shell samples being processed by pyrolysis and the chestnut shell samples chemically pretreated and then pyrolyzed. The BET and SEM results revealed that the SS had a mesoporous fluffy structure with a higher specific surface (1705 m2/g) and an average pore diameter of about 4.07 nm, providing a large number of sites for adsorption. In addition, XPS and FTIR results showed that the main component of SS was calcium oxide, and it also contained a certain amount of calcium carbonate, which not only provided an alkaline environment for the adsorption of biochar but also degradation and photocatalytic capabilities. The results showed that the MCS3-1 sample, obtained when CN and SS were mixed in the ratio of 3:1, had good capacity for adsorption for methylene blue (MB), with 1145 mg/g at an initial concentration of 1300 mg/L (92% removal rate). The adsorption behaviors were fitted with the pseudo-second-order kinetic model and Freundlich isotherm model, which indicated that the adsorption was multilayer chemisorption with a saturated adsorption capacity of 1635 mg/g. The photocatalytic capacity from the SS composition was about 89 mg/g, and the sorption of MB dye onto the sorbent reached equilibrium after 300 min. The results suggested that MCS3-1 has enormous potential for removing MB from wastewater. [ABSTRACT FROM AUTHOR]

Oxygen balance and heat of formation are closely related to the nitrogen and oxygen content in a molecule and have a significant effect on the detonation performance of energetic materials. Here a new family of 1,2,4-triazolo [4,3-b][1,2,4,5]-tetrazine containing gem-dinitromethyl and nitroamine with high nitrogen-oxygen content was synthesized and characterized. Moreover, the structure of the guanidine salt (3) and TATOT salt (4) were confirmed by single-crystal X-ray diffraction. The nitrogen and oxygen content of ammonium salt 2 reached 82.5%, with a high density (1.805 g cm−3) and high detonation properties (D = 8900 m s−1; P = 32.4 GPa), which were similar to those of RDX. [ABSTRACT FROM AUTHOR]

Numerous approaches have been developed to control the crystalline and morphology of calcium carbonate. In this paper, nanobubbles were studied as a novel aid for the structure transition from vaterite to calcite. The vaterite particles turned into calcite (100%) in deionized water containing nanobubbles generated by high-speed shearing after 4 h, in comparison to a mixture of vaterite (33.6%) and calcite (66.3%) by the reaction in the deionized water in the absence of nanobubbles. The nanobubbles can coagulate with calcite based on the potential energy calculated and confirmed by the extended DLVO (Derjaguin–Landau–Verwey–Overbeek) theory. According to the nanobubble bridging capillary force, nanobubbles were identified as the binder in strengthening the coagulation between calcite and vaterite and accelerated the transformation from vaterite to calcite. [ABSTRACT FROM AUTHOR]

The increasing demand for the lightweight production of advanced high-strength steel puts forward higher requirements for the quality of welded joint forming. The common CMT welding process has certain limitations and is difficult to meet the needs of lightweight manufacturing. In this study, the CMT + P welding technology was used to weld the DP980 dual-phase steel plate with 1.2 mm thickness. The ER120S-G welding wire was used as the filling material to conduct a 70° angle lap welding experiment. The effects of wire feeding speed (3 m/min~5 m/min) and welding speed (350 mm/min~600 mm/min) on the forming, microstructures, and mechanical properties of DP980 dual-phase steel welded joints were analyzed. The results show that the CMT + P welding process can produce lap weldments with good formability and properties. The welded joints can be divided into the weld zone, the HAZ, and the base metal zone, where the HAZ can be divided into the coarse-grained zone and the softened zone. The role of the elements Ni and Si is to promote the production of martensite and to increase the ferrite strength in welded joints. As the wire feeding speed increases, the grain size of the coarse grain zone in the HAZ increases from 31.90 μm to 50.93 μm; while the welding speed increases, the grain size of the coarse grain zone decreases from 45.48 μm to 35.73 μm. The average microhardness of the weld zone is 420 HV. In contrast, the average microhardness of the softening zone in HAZ is reduced to 250 HV. When the wire feeding speed is 4 m/min and the welding speed is 550 mm/min, the tensile properties of the weldment are optimal, its tensile strength can reach 973 MPa, and the tensile fracture is ductile fracture. [ABSTRACT FROM AUTHOR]

Utilising waste amine-oxime (WAO) resin through microwave semi-carbonization, a carbon adsorbent (CA) was obtained to remove Pb(II). After microwave treatment, the pore size of the skeleton structure, three-dimensional porous network, and lamellar pore structure of WAO was improved. The distribution coefficient (Kd) of Pb(II) onto CA is 620 mL/g, and the maximum adsorption capacity of Pb(II) is 82.67 mg/g after 20 min of WAO microwave treatment. The adsorption kinetics and adsorption isotherms conform to the quasi-second-order kinetic equation and Langmuir adsorption isotherm model, respectively. The surface of MT-WAO is negatively charged and the adsorption mechanism is mainly electrostatic interaction. Pb(II) elution in hydrochloric acid solution is more than 98%, and its recovery is high at 318 K and for 1 h. [ABSTRACT FROM AUTHOR]

The trinitromethyl moiety is a useful group for the design and development of novel energetic compounds with high nitrogen and oxygen content. In this work, by using an improved nitration method, the dinitromethyl precursor was successfully nitrated to the trinitromethyl product (2), and its structure was thoroughly characterized by FTIR, NMR, elemental analysis, differential scanning calorimetry, and single-crystal X-ray diffraction. Compound 2 has a high density (1.897 g cm−3), high heat of formation (984.8 kJ mmol−1), and a high detonation performance (D: 9351 m s−1, P: 37.46 GPa) that may find useful applications in the field of high energy density materials. [ABSTRACT FROM AUTHOR]

A wire arc additive manufacturing system, based on cold metal transfer technology, was utilized to manufacture the Al-Mg alloy walls. ER5556 wire was used as the filler metal to deposit Al-Mg alloys layer by layer. Based on the orthogonal experiments, the process parameters of the welding current, welding speed and gas flow, as well as interlayer residence time, were adjusted to investigate the microstructure, phase composition and crystal orientation as well as material properties of Al-Mg alloyed additive. The results show that the grain size of Al-Mg alloyed additive becomes smaller with the decrease of welding current or increased welding speed. It is easier to obtain the additive parts with better grain uniformity with the increase of gas flow or interlayer residence time. The phase composition of Al-Mg alloyed additive consists of α-Al matrix and γ (Al12Mg17) phase. The eutectic reaction occurs during the additive manufacturing process, and the liquefying film is formed on the α-Al matrix and coated on the γ phase surface. The crystal grows preferentially along the <111> and <101> orientations. When the welding current is 90 A, the welding speed is 700 mm/min, the gas flow is 22.5 L/min and the interlayer residence time is 5 min, the Al-Mg alloy additive obtains the highest tensile strength. Under the optimal process parameters, the average grain size of Al-Mg alloyed additive is 25 μm, the transverse tensile strength reaches 382 MPa, the impact absorption energy is 26 J, and the corrosion current density is 3.485 × 10−6 A·cm−2. Both tensile and impact fracture modes of Al-Mg alloyed additive are ductile fractures. From the current view, the Al-Mg alloys manufactured by WAAM-CMT have a better performance than those produced by the traditional casting process. [ABSTRACT FROM AUTHOR]

Biomass waste is a valuable resource that can be recovered, reused, and is renewable. However, converting biomass waste to a high degree of order is a bigger challenge, and graphitization at low temperatures is even more difficult. This paper proposes an improved method (Ni element catalysis) for highly graphitizing pomelo peel at low temperatures (750 –900 °C). In this paper, X-ray diffraction (XRD), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), Brunauer–Emmett–Teller (BET), and high-resolution transmission electron microscopy (HRTEM) were used to study the method and the effect of temperature on structural changes during graphitization. Under the improved method, pomelo peel was transformed into nano-spherical graphitized material. The degree of graphitization reached 80.23% at 900 °C, which was 31.39% higher than that of the traditional method. Furthermore, through HRTEM, the lattice fringe spacing was observed to be 0.337 nm, which is between pure graphite (0.3354 nm) and amorphous graphite (0.3440 nm). In this paper, the improved method can obtain highly graphitized nanospheres at low temperatures, thus reducing energy consumption, reducing environmental pollution, and promoting sustainable development. [ABSTRACT FROM AUTHOR]

In this study, 8% hydrogen (H2) in argon (Ar) and carbon dioxide (CO2) gas nanobubbles was produced at 10, 30, and 50 vol.% of ethanol aqueous solution by the high-speed agitation method with gas. They became stable for a long period (for instance, 20 days), having a high negative zeta potential (−40 to −50 mV) at alkaline near pH 9, especially for 10 vol.% of ethanol aqueous solution. The extended Derjaguin, Landau, Verwey, and Overbeek (DLVO) theory was used to evaluate the nanobubble stability. When the nanobubble in ethanol alkaline aqueous solution changed to an acidic pH of around 5, the zeta potential of nanobubbles was almost zero and the decrease in the number of nanobubbles was identified by the particle trajectory method (Nano site). The collapsed nanobubbles at zero charge were detected thanks to the presence of few free radicals using G-CYPMPO spin trap reagent in electron spin resonance (ESR) spectroscopy. The free radicals produced were superoxide anions at collapsed 8%H2 in Ar nanobubbles and hydroxyl radicals at collapsed CO2 nanobubbles. On the other hand, the collapse of mixed CO2 and H2 in Ar nanobubble showed no free radicals. The possible presence of long-term stable nanobubbles and the absence of free radicals for mixed H2 and CO2 nanobubble would be useful to understand the beverage quality. [ABSTRACT FROM AUTHOR]

The continuous expansion of the market demand and scale of commercial amidoxime chelating resins has caused large amounts of resin to be discarded around the world. In this study, the waste amidoxime chelating resin was reutilized as an adsorbent for the removal and recovery of Pb(II), Cu(II), Cd(II) and Zn(II) ions from aqueous solutions. The physical morphology and chemical composition of the waste amidoxime chelating resin (WAC-resin) from the factory was characterized by the elemental analyzer, X-ray photoelectron spectroscopy and Fourier-transform infrared spectroscopy. The influence of the initial metal ions concentration, contact time, temperature and the solution pH on the adsorption performance of the metal ions was explored by batch experiments. It was shown that the optimal pH was 4. Kinetic studies revealed that adsorption process corresponded with the pseudo-second-order kinetic model and the adsorption isotherm was consistent with the Langmuir model. At room temperature, the adsorption capacities of WAC-resin for Pb2+, Cu2+, Zn2+ and Cd2+ reached 114.6, 93.4, 24.4 and 20.7 mg/g, respectively. [ABSTRACT FROM AUTHOR]

The nitration of chitin monomer in a mixture of nitric acid and acetic anhydride was conducted and a highly nitrated (3R,4R,6R)-3-acetamido-6-((nitrooxy)methyl)tetrahydro-2H-pyran-2,4,5-triyl trinitrate (1) was obtained. Its structure was fully characterized using infrared spectroscopy, NMR spectroscopy, elemental analysis, and X-ray diffraction. Compound 1 possesses good density (ρ: 1.721 g·cm−3) and has comparable detonation performance (Vd: 7717 m·s−1; P: 25.6 GPa) to that of nitrocellulose (NC: Vd: 7456 m·s−1; P: 23 GPa; Isp = 239 s) and microcrystalline nitrocellulose (MCNC; Vd: 7683 m·s−1; P: 25 GPa; Isp = 250 s). However, Compound 1 has much lower impact sensitivity (IS: 15 J) than the regular nitrocellulose (NC; IS: 3.2 J) and MCNC (IS: 2.8 J). Compound 1 was calculated to exhibit a good specific impulse (Isp: 240 s), which is comparable with NC (Isp: 239 s) and MCNC (Isp: 250 s). By replacing the nitrocellulose with Compound 1 in typical propellants JA2, M30, and M9, the specific impulse was improved by up to 4 s. These promising properties indicate that Compound 1 has a significant potential as an energetic component in solid propellants. [ABSTRACT FROM AUTHOR]

We investigated the influence of microwave and conventional heating pretreatments on the grinding of cassiterite associated with pollimetallic ore. The minerals that exhibited a stronger microwave absorption ability crushed first, which is the main difference between the microwave and the traditional heating pretreatments. The distribution of Fe, Pb, Zn, and Sn increased in the fine size range (−0.425 mm). The Fe and Pb grades in the size ranges of −3.2 + 2 mm and −2 + 1 mm after the microwave pretreatment (6 kW, 1 min) were lower than those of the traditional heating (12 kW, 400 °C, 20 min), indicating that the microwave selective heating was beneficial for pyrite and jamesonite. The grade and distribution of Sn decreased significantly in the size ranges of −3.2 + 2 mm and −2 + 1 mm and increased in the size ranges of −0.425 + 0.15 mm and −0.15 + 0.074 mm. Microwave heating treatment promoted the grinding of sulfide ore and reduced the cassiterite overgrinding. [ABSTRACT FROM AUTHOR]

Nanobubbles have many potential applications depending on their types. The long-term stability of different gas nanobubbles is necessary to be studied considering their applications. In the present study, five kinds of nanobubbles (N2, O2, Ar + 8%H2, air and CO2) in deionized water and a salt aqueous solution were prepared by the hydrodynamic cavitation method. The mean size and zeta potential of the nanobubbles were measured by a light scattering system, while the pH and Eh of the nanobubble suspensions were measured as a function of time. The nanobubble stability was predicted and discussed by the total potential energies between two bubbles by the extended Derjaguin–Landau–Verwey–Overbeek (DLVO) theory. The nanobubbles, except CO2, in deionized water showed a long-term stability for 60 days, while they were not stable in the 1 mM (milli mol/L) salt aqueous solution. During the 60 days, the bubble size gradually increased and decreased in deionized water. This size change was discussed by the Ostwald ripening effect coupled with the bubble interaction evaluated by the extended DLVO theory. On the other hand, CO2 nanobubbles in deionized water were not stable and disappeared after 5 days, while the CO2 nanobubbles in 1 mM of NaCl and CaCl2 aqueous solution became stable for 2 weeks. The floating and disappearing phenomena of nanobubbles were estimated and discussed by calculating the relationship between the terminal velocity of the floating bubble and bubble size. [ABSTRACT FROM AUTHOR]

This study investigated the removal of sulfur and iron from shungite rocks through different methods after fine grinding: flotation, magnetic separation, microwave treatment, and chemical leaching. In this work, first, a mineralogical study of shungite was conducted. The carbon, silica, iron, and sulfur compositions in the as-received shungite were 45.4%, 38.3%, 4.6%, and 2.4%, respectively. In flotation, a sulfur grade of 1.4% was obtained. In the wet high-gradient magnetic separation at a magnetic flux density of 1 tesla, the iron and sulfur grades in the nonmagnetic fraction were 2.8% and 1.9%, respectively. Furthermore, the sulfur reduced to 0.2% by the 9 min microwave irradiation. In addition, chemical leaching using chelating reagents and inorganic acids was utilized to remove iron and sulfur. Nitrilotriacetic acid (NTA) could reduce the iron and sulfur grades to 2.0% and 0.9%, respectively. For leaching using reverse aqua regia, the iron and sulfur grades were reduced to 0.9% and 0.23%, respectively. For leaching using a 6N HCl with H2O2 aqueous solution, the iron and sulfur grades were reduced to 0.8% and 0.34%, respectively. Overall, chemical leaching using HCl with H2O2 was the most effective for iron and sulfur removal from shungite. [ABSTRACT FROM AUTHOR]

The phase evolution mechanism and purification of titanium oxycarbide (TiCxOy) synthesized via the carbothermal reduction of ilmenite are investigated. The reaction process and products of the performed carbothermal reduction are analyzed by means of X-ray diffraction (XRD), scanning electron microscopy-energy disperse spectroscopy (SEM-EDS), X-ray photoelectric spectroscopy (XPS) and enthalpy, entropy and heat capacity (HSC) thermodynamic software. According to the shapes of Ti 2p3/2 and Ti 2p1/2 peaks in XPS spectra, together with the XRD analyses, the reduction products of TiO, TiCxOy or TiC can be judged. The phase evolution mechanism involves FeTi2O5, Ti2O3, Fe, TiO, TiCxOy and TiC under enhancing the content of carbon. The phase evolution law can be written as FeTiO3 → FeTi2O5 → Ti2O3 + Fe → TiO + Fe → TiCxOy + Fe. Due to the incomplete reduction state of TiCxOy, the ΔGθ of TiCxOy is detected between TiC and TiO. TiCxOy could be attained under reduction conditions of Ti:C, 1:3–1:4 in argon atmosphere at 1550 °C after 2 h. Grinding, flotation and magnetic separation processes displayed that C, TiCxOy and Fe are not dissociated until the particle size of −38 μm. TiCxOy and Fe can be separated by an iron-bath in a high temperature. 95.56% TiCxOy can be obtained, and resistance of TiCxOy is less than 0.05 Ω. [ABSTRACT FROM AUTHOR]

With the target of recovering rare earth elements (REEs) from acidic leachates, a new functionalized hydrogel was designed, based on the phosphorylation of algal/polyethyleneimine beads. The functionalization strongly increased the sorption efficiency of the raw material for Pr(III) and Tm(III). Diverse techniques were used for characterizing this new material and correlating the sorption performances and mechanisms to the physicochemical structure of the sorbent. First, the work characterized the sorption properties from synthetic solutions with the usual procedures (study of pH effect, uptake kinetics, sorption isotherms, metal desorption and sorbent recycling, and selectivity from multi-element solutions). Optimum pH was found close to 5; sorption isotherms were fitted by the Langmuir equation (maximum sorption capacities close to 2.14 mmol Pr g−1 and 1.57 mmol Tm g−1). Fast uptake kinetics were modeled by the pseudo-second order rate equation. The sorbent was highly selective for REEs against alkali-earth and base metals. The sorbent was remarkably stable for sorption and desorption operation (using 0.2 M HCl/0.5 M CaCl2 solutions). The sorbent was successfully applied to the leachates of Egyptian ore (pug leaching) after a series of pre-treatments (precipitation steps), sorption, and elution. The selective precipitation of REEs using oxalic acid allows for the recovery of a pure REE precipitate. [ABSTRACT FROM AUTHOR]

Hyperspectral remote sensing images have characteristics such as high dimensionality and high redundancy. This paper proposes a pseudo-label guided artificial bee colony band selection algorithm with hypergraph clustering (HC-ABC) to remove redundant and noise bands. Firstly, replacing traditional pixel points by super-pixel centers, a hypergraph evolutionary clustering method with low computational cost is developed to generate high-quality pseudo-labels; Then, on the basis of these pseudo-labels, taking classification accuracy as the optimized objective, a supervised band selection algorithm based on artificial bee colony is proposed. Moreover, a noise filtering mechanism based on grid division is designed to ensure the accuracy of pseudo-labels. Finally, the proposed algorithm is applied in 3 real datasets and compared with 6 classical band selection algorithms. Experimental results show that the proposed algorithm can obtain a band subset with high classification accuracy for all the three classifiers, KNN, Random Forest, and SVM. [ABSTRACT FROM AUTHOR]

As life becomes richer day by day, the requirement for quality industrial products is becoming greater and greater. Therefore, image anomaly detection on industrial products is of significant importance and has become a research hotspot. Industrial manufacturers are also gradually intellectualizing how product parts may have flaws and defects, and that industrial product image anomalies have characteristics such as category diversity, sample scarcity, and the uncertainty of change; thus, a higher requirement for image anomaly detection has arisen. For this reason, we proposed a method of industrial image anomaly detection that applies a generative adversarial network based on attention feature fusion. For the purpose of capturing richer image channel features, we added attention feature fusion based on an encoder and decoder, and through skip-connection, this performs the feature fusion for the encode and decode vectors in the same dimension. During training, we used random cut-paste image augmentation, which improved the diversity of the datasets. We displayed the results of a wide experiment, which was based on the public industrial detection MVTec dataset. The experiment illustrated that the method we proposed has a higher level AUC and the overall result was increased by 4.1%. Finally, we realized the pixel level anomaly localization of the industrial dataset, which illustrates the feasibility and effectiveness of this method.