Two adsorbents, magnesium aluminum calcined hydrotalcite (MgAl LDO) and magnesium aluminum iron calcined hydrotalcite (MgAlFe LDO), were synthesized by coprecipitation method, and characterized by X?ray powder diffraction (XRD) analysis, scanning electron microscopy (SEM) analysis, Fourier transform infrared spectroscopy (FT?IR) analysis and BET specific surface area test analysis, etc. The adsorption performance of the two adsorbents for fluoride in wastewater was also studied. The effects of the ratio of metal substances, calcination temperature, initial mass concentration of F-, and adsorbent dosage on the removal efficiency of fluoride in wastewater were investigated. The results showed that MgAlFe LDO had a uniform pore structure distribution, a large specific surface area, and a higher adsorption capacity for fluoride in wastewater than that of MgAl LDO. When n (Mg2+)/n (Al3+)/n (Fe3+)=3.0∶0.6∶0.4, the initial mass concentration of F- was 20 mg/L, the calcination temperature was 300 ℃, and the dosage of MgAlFe LDO was 0.4 g, the removal effect of fluoride in wastewater was optimal. After 2 hours of reaction, the removal rate of fluoride in the wastewater was 98.35%.
Coumarins are a key class of heterocyclic lactone compounds, which have good biological activity. 3?sulfonyl coumarin derivatives were prepared by visible light promoted reaction of benzoalkynyl esters with sodium benzenesulfonate, and their reaction mechanism was studied. The results showed that under mild reaction conditions, 3?sulfonyl coumarin derivatives can be synthesized with moderate to good yields using sodium benzenesulfite as the precursor of sulfonyl radicals and persulfate as the oxidant through a cascade radical addition cyclization strategy, providing a concise, green, and efficient synthetic route for the preparation of functionalized coumarin derivatives.
The effects of a single emulsifier octylphenol ethoxylate 10 (OP?10) and its compounding system on emulsion stability, rheology and the effect of organic bases on the interfacial tension were investigated. The results show that the optimal binary composition is as follows: The mass fraction of OP?10 is 1% and the mass fraction of sodium oleate (YSN) is 0.6%.The optimum compounding method can produce stable emulsion with thick oil, and the viscosity can be reduced from 1 168.22 mPa?s to 57.57 mPa?s, with the viscosity reduction rate of 91.03% and the water separation rate of 21.33%. The organobase triethanolamine (TEOA) can reduce the interfacial tension of the compounded system to the 10-2 mN/m level.
Poly (arylpiperidine) anion exchange membrane (AEM) has been widely studied in anion exchange membrane fuel cells (AEMFCs) and alkaline electrolyzed water due to their excellent alkali resistance and stability. In this work, poly (triphenyl fluorene piperidine) (PTDP) AEM was prepared from 9,9?diphenylfluorene monomer with distorted large volume structure, and hydrophilic large volume cyclodextrin crosslinking agent (β?CD?Br7) was introduced on this basis, which can control the microphase separation structure in AEMs. The prepared qPTDP?10?CD5 AEM with 5% crosslinker content reached a high conductivity (130.2 mS/cm at 80 ℃). After the membrane was treated in 1 mol/L NaOH at 80 ℃ for 2 000 h, its conductivity retention was 94.3%, showing good stability. The H2/O2 fuel cell assembled with qPTDP?10?CD5 yielded a peak power density of 1 490 mW/cm2 at 80 ℃. In the durability test, the fuel cell assembled with qPTDP?10?CD5 showed a voltage retention rate of 89.7% after 30 h, showing good cell performance.
At present, the demand for clean energy is constantly increasing to achieve sustainable development of human society. Among numerous new energy storage and conversion devices, proton exchange membrane fuel cells (PEMFCs) can directly convert chemical energy into electrical energy. Therefore, PEMFCs have been considered to have the merits of high efficiency, safety and wide application, etc. The proton exchange membrane is the core component of PEMFCs. However, the trade?off of proton conductivity and mechanical strength has become the primary challenge to hinder the development of proton exchange membranes. Although significant progress has been made in improving the single performance, the mutual constraints of key technical properties restrict the development of proton exchange membranes. Most importantly, the road to the commercialization of fuel cells is thus tortuous. We believe that the development of flexible proton exchange membranes is a main strategy to solve this technical challenge. Based on this, this article summarizes the recent research progress on flexible proton exchange membranes,including flexible polymer materials, structural optimization, and flexible additive design, expecting to provide inspiration for breaking through the performance bottleneck of flexible proton exchange membranes.
The reduction of graphene oxide(GO), in?situ loading of SnSe and interface assembly were achieved simultaneously by microwave method, and the reduced graphene oxide(rGO)?supported the petal?shaped SnSe (SnSe/rGO) composite was successfully prepared. The SnSe/rGO was characterized by Raman spectroscopy, X?ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM), and the effects of different rGO contents for SnSe/rGO composite on the electrocatalytic oxygen reduction reaction(ORR) were investigated. The results indicated that there was an interaction between SnSe and matrix rGO, and Sn-C and Sn-O-C bonds were used as bridges of charge transfer. The intimate interconnection between the petal?like SnSe and the rGO formed a robust three?dimensional mesh structure, which served to reinforce the overall structural integrity of the catalyst, preventing its collapse. Based on this, the optimized SnSe/10%rGO catalyst (10rGO means that the mass fraction of rGO is 10%) exhibited excellent ORR activity with a limiting current density of 3.79 mA/cm2, an onset voltage (vs.RHE) of 0.85 V, and an electron transfer number of 3.10. Meanwhile, the SnSe/10%rGO catalyst performed the electrocatalysis long?term stability superior that of commercial 20%Pt/C (20%Pt means that the mass fraction of Pt is 20%) with the current density remaining 81.15% of the start value after 20 000 s of reaction. The present work offers insights into the preparation of non?precious metal cathode oxygen reduction catalytic materials for fuel cells.
A series of novel anion exchange membranes (AEMs) were prepared by constructing semi?interpenetrating polymer networks (sIPN) based on imidazole functional brominated polyphenyl ether (ImF?BPPO) and quaternary ammonium polyvinyl alcohol (QPVA). The effects of different contents of QPVA on the comprehensive properties of the composite membranes were systematically studied, the structure of the series composite membranes was analyzed by 1H?NMR and FT?IR, and the morphology of composite membrane was investigated by SEM, and the ion exchange capacity, water uptake and conductivity and other properties of the composite membranes were tested. The results show that the prepared series of composite membranes have good compatibility and no obvious phase separation phenomenon. When the mass fraction of QPVA was 40%, the water uptake and swelling rate of the composite membrane were 58.2% and 24.6%, respectively. At 80 ℃, the conductivity of the composite membrane reached 67.24 mS/cm. After soaking in 6 mol/L KOH alkaline solution for 168 h, about 90% of the initial conductivity was still retained, indicating that the membrane had good conductivity and alkali resistance stability.
The forward and reverse transportation simulation model was established by using SPS simulation software to simulate the forward and reverse operation process of A?Sai crude oil pipeline at low throughput. The change law of the oil temperature along the pipeline during the process of forward and reverse transportation is studied. The results show that the oil temperature along the pipeline decreases gradually under the steady state of forward transportation. The oil temperature drops first and then increases at the beginning of the reverse transportation, and then drops gradually after reaching the steady state.The oil temperature at the reverse inlet station decreases first and then increases slightly, and finally tends to be stable. The lowest temperature of crude oil in the process of forward and reverse transportation is the arrival temperature when the remaining crude oil is completely pushed out of the pipeline. In addition, the influence of inverse throughput on oil temperature drop during the inverse transportation was analyzed. The higher the inverse throughput is, the higher the lowest oil temperature in the process of inverse transportation is, and the faster the stable state of inverse transportation reaches. The temperature change of forward and reverse transportation obtained by SPS simulation analysis can provide certain basis for making the forward and reverse transportation scheme of A?Sai pipeline.
The study of the micro high viscosity mechanism of heavy oil is of great significance for the efficient development of Bohai heavy oil. Therefore, aiming at the typical heavy oil reservoirs in Bohai Sea, the microscopic mechanism of high viscosity of heavy oil is analyzed and studied from the aspects of viscosity?temperature relationship, crude oil composition and component polarity, heteroatom distribution and asphaltene aggregate structure. The results show that compared with N oilfield in Bohai Sea, the content of alkanes and aromatics in L oilfield in Bohai Sea is lower, and the quality score of resins and asphaltenes is higher, reaching 29.95% and 9.76% (23.25% and 6.59% in N oilfield). The quality score of heteroatoms such as O,N and S are high, and the relative molecular mass of resins and asphaltenes are also high. The polarity of each component is strong, and the dipole moments of resins and asphaltenes reach 14.01 D and 17.94 D, respectively (9.12 D and 12.25 D in N oilfield ). These will lead to stronger intermolecular forces and stronger intermolecular association between resins and asphaltenes. The smaller asphaltene molecular spacing and the denser aggregate structure,which will eventually lead to higher viscosity of crude oil.
Ultra?deep wells of over 10 000 meters have been successfully drilled in China, and deeper breakthroughs has been made in drilling and completion equipment technology, which indicates that China has achieved a significant milestone in the field of oil exploration and development. It is crucial to improve drilling efficiency and ensure safety in this context. Intelligent drilling and completion technology is a core solution to the challenges faced in the industry. It offers significant advantages in improving drilling efficiency and safety. By integrating advanced automation control, real?time data monitoring, and machine learning technology, it optimizes drilling operations. This not only improves drilling efficiency but also dramatically enhances drilling and completion safety. This paper summarizes the current development status of intelligent drilling and completion equipment technology. It proposes a trinity research approach that includes automation control, real?time data monitoring, and machine learning technology. The paper focuses on analyzing the development journey and technological innovation of domestic and international innovative equipment, such as intelligent drill bits, intelligent guiding tools, intelligent drill pipes, intelligent slip sleeves, and intelligent drilling rigs. To achieve comprehensive development of intelligent drilling and completion equipment technology in the future, it is recommended to utilize artificial intelligence, intelligent optimization algorithms, and foster domestic and international cooperation.
To address the issues of scarce small defect samples and poor detection accuracy in magnetic flux leakage (MFL) testing of oil and gas pipelines, this paper proposes a small defect detection network for oil and gas pipelines on the basis of shallow feature suppression. First, an adversarial generative network is utilized, which incorporates prior knowledge to generate high?quality small defect samples. Subsequently, a defect feature suppression module is introduced during the feature extraction process, which suppresses the semantics of large defects in shallow pyramid features, thereby enhancing the features of small defects. Finally, a multi?scale Transformer is employed to fully leverage the local details and global information of the feature images, improving the accuracy of pipeline defect detection. The experimental results demonstrate that the accuracy of this model is 95.1%, which is 7.8% higher than the average value of existing faster R?CNN and other methods methods.
A perception and detection system based on cameras achieves target detection with lower cost and higher resolution. Target detection is performed using bird's?eye view (BEV) features generated by six monocular cameras. These BEV features include the position and scale of objects, making them suitable for various autonomous driving tasks. BEV detectors are typically combined with the deep pre?trained image backbones, but directly connecting the two does not effectively highlight the correspondence between 2D and 3D features. To address this issue, Channel Attention is applied to weight and adjust the proposed feature channels in the output feature map, and combined with a depth estimation module to emphasize the relationship between 2D and 3D features. Furthermore, a temporal aggregation fusion method is employed to solve the problem of gradual information loss in traditional fusion methods, ensuring that the model can fully leverage historical information. Extensive experiments on the NuScenes dataset show that the model achieves a Normalized Discounted Cumulative Score (NDS) of 0.604, a 0.035 improvement over the BEVFormer model, validating the effectiveness of the proposed approach.