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Multiple-input multiple-output (MIMO) technology is widely used in the field of radar imaging. Array sparse optimization reduces the hardware cost of MIMO radar, while virtual aperture and the equivalent phase center (EPC) principle simplify the radar signal model and reduce the computation and complexity of imaging algorithms. However, the application of sparse array structure and the EPC principle produces a non-negligible phase error, which affects the imaging quality. This paper simplifies the MIMO radar signal model based on the phase center approximation, analyzes the phase error generated by this method, and proposes an improved phase error correction method to solve the problem that the target cannot be well-focused at non-reference distance during imaging. In addition, this paper designs a sparse linear MIMO array with a periodic structure, which reduces the number of transmitting and receiving units, system complexity, and hardware costs. The proposed phase correction method was combined with the wavenumber domain algorithm to simulate and experiment on the designed antenna array, and good experimental results were obtained to verify the effectiveness of the proposed method. [ABSTRACT FROM AUTHOR]

Background: In recent years, the advancement of computational chemistry has offered new insights into the rational design of molecularly imprinted polymers (MIPs). From this aspect, our study tried to give quantitative parameters for evaluating imprinting efficiency and exploring the formation mechanism of MIPs by combining simulation and experiments. Methods: The pre-polymerization system of sulfadimethoxine (SDM) was investigated using a combination of quantum chemical (QC) calculations and molecular dynamics (MD) simulations. MIPs were prepared on the surface of silica gel by a surface-initiated supplemental activator and reducing agent atom transfer radical polymerization (SI-SARA ATRP). Results: The results of the QC calculations showed that carboxylic monomers exhibited higher bonding energies with template molecules than carboxylic ester monomers. MD simulations confirmed the hydrogen bonding sites predicted by QC calculations. Furthermore, it was observed that only two molecules of monomers could bind up to one molecule of SDM, even when the functional monomer ratio was up to 10. Two quantitative parameters, namely, the effective binding number (EBN) and the maximum hydrogen bond number (HBNMax), were defined. Higher values of EBN and HBNMax indicated a higher effective binding efficiency. Hydrogen bond occupancies and RDF analysis were performed to analyze the hydrogen bond formation between the template and the monomer from different perspectives. Furthermore, under the influence of the EBN and collision probability of the template and the monomers, the experimental results show that the optimal molar ratio of template to monomer is 1:3. Conclusions: The method of monomer screening presented in this study can be extended to future investigations of pre-polymerization systems involving different templates and monomers. [ABSTRACT FROM AUTHOR]

Posttransplantation complications pose a major challenge to the long‐term survival and quality of life of organ transplant recipients. These complications encompass immune‐mediated complications, infectious complications, metabolic complications, and malignancies, with each type influenced by various risk factors and pathological mechanisms. The molecular mechanisms underlying posttransplantation complications involve a complex interplay of immunological, metabolic, and oncogenic processes, including innate and adaptive immune activation, immunosuppressant side effects, and viral reactivation. Here, we provide a comprehensive overview of the clinical features, risk factors, and molecular mechanisms of major posttransplantation complications. We systematically summarize the current understanding of the immunological basis of allograft rejection and graft‐versus‐host disease, the metabolic dysregulation associated with immunosuppressive agents, and the role of oncogenic viruses in posttransplantation malignancies. Furthermore, we discuss potential prevention and intervention strategies based on these mechanistic insights, highlighting the importance of optimizing immunosuppressive regimens, enhancing infection prophylaxis, and implementing targeted therapies. We also emphasize the need for future research to develop individualized complication control strategies under the guidance of precision medicine, ultimately improving the prognosis and quality of life of transplant recipients. [ABSTRACT FROM AUTHOR]

The Larsemann Hills are located on the eastern coast of the Prydz Bay in East Antarctica. Based on large-scale geological mapping, metamorphic complex in the Larsemann Hills was found to be layered orderly in general, and therefore, the Larsemann Group is established. The Larsemann Group is subdivided into 6 rock formations, and the protolith formation age is the Mesoproterozoic. The group has experienced the superposition of the Grenvillian and Pan-African metamorphism, and the metamorphic grade reached upper amphibolite facies to granulite facies. The main structural line in the Larsemann Hills is in the NEE-SWW strain, which generally constitutes a synclinorum structure verging to NEE. The distribution of several rock formations also shows the gradually younging from east to west. The NNW-SSE deformation of the structural line is obviously superimposed on the eastern Mirror Peninsula. The study shows that the Larsemann Group has suffered 6 periods of deformation, including the early Neoproterozoic Grenvillian period (D1), the late Neoproterozoic to early Paleozoic Pan-African periods (D2, D3, D4 and D5) and the Meso-Cenozoic extension (D6). The foliations presented in the rocks are actually the composite foliations of both the Grenvillian and Pan-African events, and the Pan-African event is demonstrated stronger than the Grenvillian event, which is rarely preserved in the gneisses. Constrained with both the metamorphic age of the Larsemann Group and the intrusion time of the Progress granite, it is believed that the D2~D5 deformations occurred during the span of 550~500 Ma. Thus, both the metamorphism and deformation features of rocks from the Larsemann Hills show that the Mesoproterozoic Larsemann Group have witnessed two orogenies of Grenvillian and Pan-African periods, respectively, and the breakup of the Gondwana.

Fault diagnosis is one of the important applications of edge computing in the Industrial Internet of Things (IIoT). To address the issue that traditional fault diagnosis methods often struggle to effectively extract fault features, this paper proposes a novel rolling bearing fault diagnosis method that integrates Gramian Angular Field (GAF), Convolutional Neural Network (CNN), and Vision Transformer (ViT). First, GAF is used to convert one-dimensional vibration signals from sensors into two-dimensional images, effectively retaining the fault features of the vibration signal. Then, the CNN branch is used to extract the local features of the image, which are combined with the global features extracted by the ViT branch to diagnose the bearing fault. The effectiveness of this method is validated with two datasets. Experimental results show that the proposed method achieves average accuracies of 99.79% and 99.63% on the CWRU and XJTU-SY rolling bearing fault datasets, respectively. Compared with several widely used fault diagnosis methods, the proposed method achieves higher accuracy for different fault classifications, providing reliable technical support for performing complex fault diagnosis on edge devices. [ABSTRACT FROM AUTHOR]