A magnesium aluminum bimetallic organic framework derivative (MgAl-DHBDC/LDH composite) was prepared by etching MgAl bimetallic MOF template and used to remove U(VI) in aqueous solution. Compared to ...MgAl-DHBDC, the stability, dispersibility and removal ratio of U(VI) with MgAl-DHBDC/LDH were improved significantly over a wide pH range. The adsorption of uranium by MgAl-DHBDC/LDH was mainly multilayer physical adsorption, and the adsorption process was a spontaneous endothermic process. Moreover, the removal ratio of U(VI) by the MgAl-DHBDC/LDH composite remained above 90% after 4 cycles, indicating good regeneration performance. The MgAl-DHBDC/LDH composite shows great potential in the remediation of radionuclide uranium wastewater.
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To solve the problems of the poor stability and low adsorption efficiency of MXene used as an adsorbent for heavy metal removal. In this study, the microwave-assisted novel composite of chloroacetic ...acid-modified MXene-chitosan gel microspheres (C-TC-CS) was prepared. The experimental results demonstrated that C-TC-CS exhibited good stability and U(VI) adsorption performance, the maximum adsorption capacity of U(VI) by C-TC-CS was up to 141.96 mg/g. Pseudo-second-order and Langmuir isotherm adsorption models fit the adsorption process well, and the thermodynamic parameters showed that the adsorption process was spontaneous and endothermic. Importantly, C-TC-CS could be easily separated and regenerated. After five cycles of regeneration, the adsorption efficiency of C-TC-CS for U(VI) remained above 74%. Spectroscopic analyses indicated that the main adsorption mechanism involved electrostatic interactions, ion exchange, and complexation. This study proved that C-TC-CS could be an effective and promising adsorbent for removing U(VI) from aqueous solution.
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•C-TC-CS gel microspheres firstly synthesized and used for U(VI) adsorption.•C-TC-CS gel microsphere exhibit the maximum adsorption capacities (141.96 mg/g) for U(VI) by Langmuir model.•The C-TC-CS gel microspheres display enhanced physicochemical properties and adsorption capacity.•The main adsorption mechanism of C-TC-CS on U(VI) contain electrostatic interaction, ion exchange and complexation.
Federated Learning (FL) is a distributed machine learning paradigm that trains models across multiple devices without exchanging users' data, thereby providing stronger data privacy guarantees. ...However, some research reveals that FL may face security and privacy issues, such as single point of failure, model poisoning, and parameter privacy disclosure. Recently, the field of combining blockchain and FL has a trend to become a hot research topic. More and more researchers attempt to use blockchain to decentralize and secure FL frameworks. To further understand recent advances in blockchain-based FL (BFL) systems, this article aims to provide a systematic survey to deconstruct BFL systems. We propose a taxonomy of BFL systems following the lifecycle of FL tasks and divide them into three layers, <inline-formula> <tex-math notation="LaTeX">i.e. </tex-math></inline-formula>, the blockchain layer, the training layer, and the aggregation layer. We review and summarize representative work in each layer. We also discuss several open challenges for designing more secure and efficient BFL systems.
The structural, mechanical, elastics anisotropy and electronic properties of Ca1−xMgxO in the cubic structure are investigated using density functional theory calculations. The lattice parameters, ...elastic constants and elastic modulus are in excellent agreement with the experimental and others theoretical data. The sound velocities and the Debye temperatures are calculated for all the Ca1−xMgxO alloys using the calculated elastic constants and elastic modulus. The elastic anisotropy are characterized by calculating several different anisotropic indexes and describing the three dimensional surface constructions. Finally, electronic structure studies show that Ca1−xMgxO alloys are direct band gap semiconductors.
Endoscopic surgery is increasing for minimally invasive treatment in recent years.But the conventional two-dimensional endoscope technique cannot provide three-dimensional information for surgeon. ...Lacking depth and other 3D information often made doctorshave to carry out the surgery depending heavily clinical experience.In response to the above described issues,this paper proposed a method based on improved SIFT algorithmto recover 3D structure information of the endoscopic environment, with the help of an optical tracking system which can provide the orientation of the camera in real time. The proposed approach is evaluated on sequence digital images gotten from an 1394 camera and the experimental results show that the proposed approach iseffective.
Automatic equipmenttransportation in the wild complex terrain circumstances is very important in rescue or military. In this paper, an accompanying system based on the identification and tracking of ...infrared LEDmarkers is proposed. This system avoidsthe defect that visible-light identification method has. In addition, this paper presents a Kalman filter to predict where infraredmarkers may appear in the nextframe imageto reduce the searchingarea of infrared markers, which remarkablyimproves the identificationspeed of infrared markers. The experimental results show that the algorithm proposed in this paper is effective and feasible.
