Bridge expansion and contraction installation (BECI) has proved to be an essential component of the bridge structure due to its stability, comfort, and durability benefits. At present, traditional ...replacement technologies for modular type, comb plate type, and seamless type BECIs are widely applied worldwide. Nevertheless, it is unfortunate that the research conducted on decision-making (DM) approaches for the technical condition assessment and the optimal replacement plan selection of existing BECIs remain scarce, which results in the waste of resources and the increase in cost. Therefore, a BECI technical condition assessment approach, which contains specific on-site inspection regulations with both qualitative and quantitative descriptions, is proposed in this research, and a corresponding calculation program has been developed based on the MATLAB platform, which provides the basis for the necessity of replacement. Simultaneously, the hybrid chaotic whale optimization algorithm is designed and performed to improve and automate the process of optimal replacement plan selection under the assistance of the analytic hierarchy process (AHP), where both the achievement in consistency modification and the reservation of initial information are perused, and its superiority and effectiveness are verified via the comparative experimental analysis. The improved BECI replacement decision system is established, and the corresponding case study demonstrates that the proposed system in this research proves reasonable and feasible. The improved system can effectively assist bridge managers in making more informed operation and maintenance (O and M) decisions in actual engineering projects.
The presence of topological flat minibands in moiré materials provides an opportunity to explore the interplay between topology and correlation. In this work, we study moiré minibands in topological ...insulator films with two hybridized surface states under a moiré superlattice potential created by two-dimensional insulating materials. We show the lowest conduction (highest valence) Kramers' pair of minibands can be
non-trivial when the minima (maxima) of moiré potential approximately form a hexagonal lattice with six-fold rotation symmetry. Coulomb interaction can drive the non-trivial Kramers' minibands into the quantum anomalous Hall state when they are half-filled, which is further stabilized by applying external gate voltages to break inversion. We propose the monolayer Sb
on top of Sb
Te
films as a candidate based on first principles calculations. Our work demonstrates the topological insulator based moiré heterostructure as a potential platform for studying interacting topological phases.
Bridge expansion and contraction installation (BECI) has proved to be an indispensable component of bridge structures due to its stability, comfort, and durability benefits. At present, conventional ...replacement technologies for modular-type, comb plate-type, and seamless-type BECIs are widely applied worldwide. However, it is unfortunate that there remains no systematic research on quantitative assessment approaches for evaluating the overall technical status and selecting optimal replacement methods for existing BECIs. Therefore, considering the installation performance according to functional index evaluations and the economic cost based on life-cycle value assessment (LCVA), a standardized quantitative assessment approach is proposed for optimal replacement method selection in this article. Simultaneously, the other new quantitative assessment method is developed for evaluating the overall technical status of BECIs, which provides a basis for the necessity of replacement. A BECI replacement decision system is constructed, and a corresponding case study illustrates that the proposed system based on the analytic hierarchy process (AHP) in this article proves to be reasonable and feasible. The results reveal that the selected replacement method with both a higher function coefficient and a lower economic coefficient can not only fulfil the performance requirements but also pursue a cost reduction, which leads to a considerable value increment. This system can effectively assist bridge managers in making appropriate operation and maintenance (O and M) decisions in actual engineering projects.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
Abstract
Van der Waals dielectrics are fundamental materials for condensed matter physics and advanced electronic applications. Most dielectrics host isotropic structures in crystalline or amorphous ...forms, and only a few studies have considered the role of anisotropic crystal symmetry in dielectrics as a delicate way to tune electronic properties of channel materials. Here, we demonstrate a layered anisotropic dielectric, SiP
2
, with non-symmorphic twofold-rotational
C
2
symmetry as a gate medium which can break the original threefold-rotational
C
3
symmetry of MoS
2
to achieve unexpected linearly-polarized photoluminescence and anisotropic second harmonic generation at SiP
2
/MoS
2
interfaces. In contrast to the isotropic behavior of pristine MoS
2
, a large conductance anisotropy with an anisotropy index up to 1000 can be achieved and modulated in SiP
2
-gated MoS
2
transistors. Theoretical calculations reveal that the anisotropic moiré potential at such interfaces is responsible for the giant anisotropic conductance and optical response. Our results provide a strategy for generating exotic functionalities at dielectric/semiconductor interfaces via symmetry engineering.
Two-dimensional (2D) layered materials have been studied in depth during the past two decades due to their unique structure and properties. Transition metal (TM) intercalation of layered materials ...have been proven as an effective way to introduce new physical properties, such as tunable 2D magnetism, but the direct growth of atomically thin heteroatoms-intercalated layered materials remains untapped. Herein, we directly synthesize various ultrathin heteroatoms-intercalated 2D layered materials (UHI-2DMs) through flux-assisted growth (FAG) approach. Eight UHI-2DMs (V1/3NbS2, Cr1/3NbS2, Mn1/3NbS2, Fe1/3NbS2, Co1/3NbS2, Co1/3NbSe2, Fe1/3TaS2, Fe1/4TaS2) were successfully synthesized. Their thickness can be reduced to the thinnest limit (bilayer 2D material with monolayer intercalated TM), and magnetic ordering can be induced in the synthesized structures. Interestingly, due to the possible anisotropy-stabilized long-range ferromagnetism in Fe1/3TaS2 with weak interlayer coupling, the layer-independent magnetic ordering temperature of Fe1/3TaS2 was revealed by magneto-transport properties. This work establishes a general method for direct synthesis of heteroatom-intercalated ultrathin 2D materials with tunable chemical and physical properties.The intercalation of heteroatoms has been demonstrated to be an effective approach to introduce new physical properties in 2D layered materials (2DMs). Here, the authors report a flux-assisted growth method to synthesize various ultrathin heteroatoms-intercalated 2DMs, showing evidence of anisotropy-stabilized long-range ferromagnetism in Fe1/3TaS2.
In recent decades, structural damage identification based on the wavelet analysis method has been widely developed, but it is still confronted with many difficulties, such as large decomposition ...error and complex data. In order to overcome the shortcomings of analysis based on wavelet, the wavelet packet analysis method is adopted to decompose the acceleration data into wavelet packets, and the frequency band energy value after wavelet packet decomposition (WPE) is taken as the different dimensions of the Mahalanobis distance squared (MDS) in this study, where the MDS value of the same element between different samples is calculated, and the mean value of 30 groups of MDS values for each element is processed. The change rate between the MDS value of the element that exceeds the MDS value in the healthy state and the MDS mean value in the healthy state as the objective function. The combination of weight coefficient and hyperbolic tangent function is used to improve the simulated annealing particle swarm optimization (SAPSO) algorithm, and the improved hyperbolic tangent function-simulated annealing particle swarm optimization (HTF-SAPSO) is used to iteratively calculate the damage severity. The numerical simulation and vibration testing of a steel beam are conducted to verify the identification performance of damage location and the analysis of damage severity by this method, respectively. The numerical model of the experimental I-beam is established based on the MATLAB modeling platform, and the different damage cases are utilized to illustrate the correctness of this study. The different proportions of noise effects are adopted to the numerical simulation analysis, where the correlations between noise effects and MDS value and damage severity are analyzed. In the numerical simulation, although the MDS value increases to different degrees with the increase of the noise ratio, the damage identification result of the damaged element remains mostly constant, which indicates that the influence is negligible. In conclusion, it is feasible to construct the damage index via the combination of WPE and MDS values, the damage location can be judged from whether the MDS value of the element exceeds the threshold, and the HTF-SAPSO algorithm is more efficient and accurate to be adopted in the quantification of the damage severity.
This paper focused on the problem of diagnosis of Alzheimer’s disease via the combination of deep learning and radiomics methods. We proposed a classification model for Alzheimer’s disease diagnosis ...based on improved convolution neural network models and image fusion method and compared it with existing network models. We collected 182 patients in the ADNI and PPMI database to classify Alzheimer’s disease, and reached 0.906 AUC in training with single modality images, and 0.941 AUC in training with fusion images. This proved the proposed method has better performance in the fusion images. The research may promote the application of multimodal images in the diagnosis of Alzheimer’s disease. Fusion images dataset based on multi-modality images has higher diagnosis accuracy than single modality images dataset. Deep learning methods and radiomics significantly improve the diagnosing accuracy of Alzheimer’s disease diagnosis.
Polyene synthesis: An efficient approach to the total synthesis of polyene natural product dihydroxrulin (1) is described. A novel, mild, direct organocatalytic IBX‐mediated dehydrogenation process ...of simple alcohols to enals has been developed, which serves as a key step in the synthesis (see scheme).
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Parkinson's disease (PD) is a common chronic occult neurological degeneration disease which is most likely to occur among middle-aged and old-aged people. Neuroprotective methods can significantly ...slow the PD progression, therefore early diagnosis and the treatment of the PD is crucial. As the second most common neurodegenerative disorder, Parkinson's disease has its identification based on clinical diagnoses. Early diagnosis is especially important due to the lack of radical treatment. In all early diagnostic methods, results of imaging diagnosis based on positron emission tomography (PET) imaging has the most outstanding accuracy. Deep learning methods based on convolutional neural networks performed well in diagnosing different diseases. To address the demand of early diagnosis, this paper applies several preprocessing methods to image data such as gray level transformation, histogram equalization, improved wavelet soft-threshold denoising and image enhancement, and proposes a deep learning model based on U-Net architecture with deformable convolution kernels. After comparing the results of both methods, we found out that deformable U-Net outperformed the previously built improved VGG-Net. These results show that U-Net with deformable convolution structure has a good diagnostic capability and a better performance than the improved VGG-Net.
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