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Printed Circuit Boards (PCBs) are the foundational component of electronic devices, and the detection of PCB defects is essential for ensuring the quality control of electronic products. Aiming at the problem that the existing PCB plug-in solder defect detection algorithms cannot meet the requirements of high precision, low false alarm rate, and high speed at the same time, this paper proposes a method based on spatial convolution pooling and information fusion. Firstly, on the basis of YOLOv3, an attention-guided pyramid structure is used to fuse context information, and multiple convolutions of different size are used to explore richer high-level semantic information; Secondly, a coordinated attention network structure is introduced to calibrate the fused pyramidal feature information, highlighting the important feature channels, and reducing the adverse impact of redundant parameters generated by feature fusion; Finally, the ASPP (Atrous Spatial Pyramid Pooling) structure is implemented in the original Darknet53 backbone feature extraction network to acquire multi-scale feature information of the detection targets. With these improvements, the average detection accuracy of the enhanced network has been elevated from 94.45 to 96.43%. This experiments shows that the improved network is more suitable for PCB plug-in solder defect detection applications. [ABSTRACT FROM AUTHOR]

This study aimed to investigate the relationship and potential mechanisms of miR‐200c‐5p in colorectal cancer (CRC) progression. Differentially expressed miRNAs were screened using the TCGA database. Subsequently, univariate analysis was performed to identify CRC survival‐related miRNAs. Survival and receiver operator characteristic curves were generated. The target genes of miR‐200c‐5p and the relevant signaling pathways or biological processes were predicted by the miRNet database and enrichment analyses. The miR‐200c‐5p expression was detected using quantitative reverse‐transcription polymerase chain reaction, Cell Counting Kit‐8, Transwell, and cell apoptosis experiments were performed to determine miR‐200c‐5p's impact on CRC cell viability, invasiveness, and apoptosis. Finally, we constructed a CRC mouse model with inhibited miR‐200c‐5p to evaluate its impact on tumors. miR‐200c‐5p was upregulated in CRC, implying a favorable prognosis. Gene set enrichment analysis revealed that miR‐200c‐5p may participate in signaling pathways such as the TGF‐β signaling pathway, RIG‐I‐like receptor signaling pathway, renin‐angiotensin system, and DNA replication. miR‐200c‐5p potentially targeted mRNAs, including KCNE4 and CYP1B1, exhibiting a negative correlation with their expression. Furthermore, these mRNAs may participate in biological processes like the regulation of intracellular transport, cAMP‐dependent protein kinase regulatory activity, ubiquitin protein ligase binding, MHC class II protein complex binding, and regulation of apoptotic signaling pathway. Lastly, miR‐200c‐5p overexpression repressed the viability and invasiveness of CRC cells but promoted apoptosis. The tumor size, weight, and volume were significantly increased by inhibiting miR‐200c‐5p (p < 0.05). miR‐200c‐5p is upregulated in CRC, serving as a promising biomarker for predicting CRC prognosis. [ABSTRACT FROM AUTHOR]

Finding the densest subgraph has tremendous potential in computer vision and social network research, among other domains. In computer vision, it can demonstrate essential structures, and in social network research, it aids in identifying closely associated communities. The densest subgraph problem is finding a subgraph with maximum mean density. However, most densest subgraph-finding algorithms are based on edge-weighted graphs, where edge weights can only represent a single value dimension, whereas practical applications involve multiple dimensions. To resolve the challenge, we propose two algorithms for resolving the densest subgraph problem in a vertex-weighted graph. First, we present an exact algorithm that builds upon Goldberg's original algorithm. Through theoretical exploration and analysis, we rigorously verify our proposed algorithm's correctness and confirm that it can efficiently run in polynomial time O(n(n + m)log2n) is its temporal complexity. Our approach can be applied to identify closely related subgroups demonstrating the maximum average density in real-life situations. Additionally, we consistently offer an approximation algorithm that guarantees an accurate approximation ratio of 2. In conclusion, our contributions enrich theoretical foundations for addressing the densest subgraph problem. [ABSTRACT FROM AUTHOR]

This work carefully revisits the topic of dynamic feedback $ H_{\infty } $ H ∞ control problem for discrete singular systems (DSSs) with time–varying delays. A new state decomposed Lyapunov-Krasovskii functional is presented by a discrete state decomposition method. For the unforced nominal DSSs, delay–dependent sufficient conditions with an $ H_{\infty } $ H ∞ performance index are derived. Based on these conditions, a closed–loop system being regular and causal is developed via a dynamic feedback controller. As a new discrete state decomposition–reorganization method is proposed, the required admissibility conditions are attained. Through the accurate calculation of each decomposition component of the dynamic feedback controller, the desired dynamic feedback controller settings are determined. The numerical findings demonstrate the superiority of our method over earlier approachers, and the results are less conservative. [ABSTRACT FROM AUTHOR]

Based on nonlinear memory feedback, the robust admissibility problem of a class of singular nonlinear time-delay systems was investigated. First, an equivalent structural model of the system was created using the state decomposition approach. Then, sufficient criteria for the robust admissibility of the system were obtained in the form of linear matrix inequalities using the Lyapunov–Krasovskii theory and free weighted matrix method. Subsequently, the closed-loop robust admissibility of the system under nonlinear memory feedback control was investigated using similar research techniques as before, yielding corresponding results. The intended design controller was obtained by explicitly computing each component in the deconstructed structure of the nonlinear memory feedback controller. Importantly, the flexibility and viability of the planned control design could be enhanced by the algorithm for solving controller gain through this component decomposition. Finally, numerical examples confirmed the feasibility of the method. [ABSTRACT FROM AUTHOR]

In this study, model predictive control (MPC) was considered for a class of discrete time-delay systems with external disturbances. Equivalent input disturbance (EID) is a commonly utilized active disturbance rejection technique that enhances the rejection of system disturbances. Any disturbance can be effectively suppressed using the EID approach, leaving no traces of the disturbance. This paper proposes a novel MPC control approach that combines the EID method with the MPC principle. An MPC law with disturbance-rejection performance was presented after obtaining and combining the EID estimates with performance indicators using the EID method. Optimizing the performance index is then converted into a semi-definite problem comprising of an objective function and linear matrix inequality through building a Lyapunov function. Based on this basis, an MPC design algorithm is proposed. A numerical simulation was conducted to confirm superiority and efficacy of the proposed method. [ABSTRACT FROM AUTHOR]

Biogenic volatile organic compounds (BVOCs) significantly contribute to atmospheric chemistry at both regional and global scales. The composition and intensity of BVOC emissions vary significantly among different plant species. Previous studies have focused on BVOC emissions from tree species, but the results of research on BVOC emissions from wetland plants are still limited. Therefore, in this study, BVOCs emitted by three aquatic plants (Phragmites australis, Typha angustifolia, and Iris pseudacorus) were sampled and analyzed using a dynamic headspace technique combined with GC-MS at daily scales. The diurnal observation data showed that the total BVOC emission rates of the three plants peaked with the increase in environmental factors (temperature, PAR, and water temperature). P. australis was the only of the three plants that emitted isoprene with a high rate of 48.34 μg·g−1Dw·h−1. Moreover, the peak emission rates of total BVOC (78.45 μg·g−1Dw·h−1) in P. australis were higher than most tree species. The emissions rates of volatile organic compounds, including monoterpenes, oxygenated volatile organic compounds, alkanes, and other volatile organic compounds, were statistically correlated across all species. The emission rates of isoprene from P. australis had significant associations with intercellular CO2 concentration (Ci) (0.58, p < 0.05) and transpiration rate (Tr) (−0.63, p < 0.01). The emission rates of monoterpenes from P. australis were found to have a significantly positive correlation with the net photosynthetic rate (Pn) (0.58, p < 0.05) while T. angustifolia (−0.59, p < 0.05) and I. pseudacorus (−0.47, p < 0.05) showed the opposite trend. Such findings hold significance for the refinement of localized emission inventories and the development of comprehensive emission process models in future research, as BVOC emissions from wetland plants were reported here for the first time. [ABSTRACT FROM AUTHOR]

Roughness, in various distributions and on various scales, is widely encountered in turbine modules and has a complex modulating effect on the distribution of film cooling effectiveness. In this study, the fast-response pressure-sensitive paint technique was utilized to analyze the steady and unsteady behaviors of film cooling effectiveness under various roughness conditions. Two roughness conditions (upstream roughness and the combination of upstream and downstream roughness) were examined at three roughness scales (ks/D = 0.016, 0.129, and 0.782) and three blowing ratios (M = 0.5, 1.0, and 1.5). Comparisons of the steady behaviors of cooling effectiveness revealed that upstream roughness was the primary factor influencing cooling effectiveness for the adequate film attachment (M = 0.5 and 1.0) and that the cooling effectiveness deteriorated with rising ks/D. Downstream roughness improved the cooling effectiveness in cases with poor film attachment (M = 1.5). Considering that the distribution of film cooling effectiveness is modulated by the vortical structures of jet in crossflow, the unsteady behaviors of roughness-affected cooling effectiveness were analyzed through proper orthogonal decomposition. Upstream roughness influenced the counter-rotating vortex pair and horseshoe vortex (HV) signatures by separately widening and shortening the patterns in the lateral and streamwise directions, a trend that became more pronounced with increasing ks/D values. Moreover, larger roughness scales at lower blowing ratios caused asymmetry in the signatures. Downstream roughness primarily affected the signatures through local morphological variations, inducing oscillations in modal patterns. For attached films, downstream roughness had a nonsignificant impact, while for detached films, disturbances caused by downstream roughness resulted in vague and asymmetric modal patterns. Evaluation of the reconstructed cooling effectiveness revealed that roughness tended to affect the unsteady behavior of HV-modulated cooling effectiveness at high frequencies. These clarified steady and unsteady behaviors across various roughness conditions provide references for improving film-cooling structures to accommodate diversely roughened turbine modules. [ABSTRACT FROM AUTHOR]

The stabilization problem for uncertain discrete‐time singular Markovian jump systems (DSMJSs) with time‐varying delays is comprehensively covered in this paper. An updated Lyapunov–Krasovskii functional is presented via a discrete state decomposition method. With the help of this constructed Lyapunov–Krasovskii functional, some delay‐ and mode‐dependent sufficient conditions for the open‐loop DSMJSs are derived. Based on these circumstances, a memory mode‐dependent state feedback control is used to create a closed‐loop DSMJS with parameter uncertainties that is regular and causal. And then, the stochastically admissible conditions are attained. Through the exact calculation of each decomposition component for the designed memory state feedback controller, the intended memory state feedback controller settings are determined. It should be mentioned that the algorithm suggested in this article expands the controller design's feasibility and flexibility. The numerical results show how the approach is superior to previous ones, and the given results are less conservative. [ABSTRACT FROM AUTHOR]

The identification and quantification of the ecological risks, sources and distribution of heavy metals in purple soils are essential for regional pollution control and management. In this study, geo-accumulation index (Igeo), enrichment factor (EF), pollution index (PI), potential ecological risk index (RI), principal component analysis (PCA) model and geographical detector (GD) were combined to evaluate the status, ecological risk, and sources of heavy metals (HMs) in soils from a typical purple soil areas of Sichuan province. The results showed that the average contents of As, Cd, Cr, Cu, Hg, Ni, Pb and Zn in purple soil were 7.77, 0.19, 69.5, 27.9, 0.077, 30.9, 26.5 mg/kg and 76.8 mg/kg, and the Igeo, EF and RI of topsoil Hg and Cd in designated area was the highest, and the average contents of Hg and Cd in topsoil were obviously greater than respective soil background value in Sichuan province and purple soil. The hot spots for the spatial distribution of 8 HMs were mainly focused in the southwest and northeast of the designated area, and there were also significant differences for 8 HMs distribution characteristics in the profile soil. Cu comes from both anthropogenic and natural sources, Zn, Ni and Cr mainly come from natural sources, but As, Pb, Hg and Cd mainly derived from human activities. GD results showed that soil texture (X18), altitude (X4), total nitrogen (TN), clay content (X3), sand content (X2) and silt content (X1) had the greatest explanatory power to 8 HMs spatial differentiation.This study provides a reference for understanding the status and influencing factors of HM pollution in typical purple soil, and lays a theoretical foundation for the environmental treatment of purple soil in China. [ABSTRACT FROM AUTHOR]

Soil heavy metal contamination poses a significant threat to both environmental health and ecological safety. To investigate the influencing factors, ecological hazards, and sources analysis of heavy metals in purple soil, 27 sets of soil samples were collected from varying genetic horizons within Guang'an City, and the contents of As, Cd, Cu, Cr, Hg, Ni, Pb, and Zn were analyzed. The results indicated higher concentrations of heavy metals in soil A horizon, compared to that of C horizon. The relevance analysis indicated that the soil's heavy metals were strongly correlated with the soil's physicochemical properties. The enrichment factor, pollution load index, and potential risk index highlighted slightly to severely polluted levels of soil Cd and Hg, which significantly contribute to the ecological hazards posed by soil heavy metals. The potential source of heavy metals analyzed using the APCS-MLR model identified both anthropogenic inputs and natural sources as primary contributors to heavy metal presence in soils. The Cu, Cr, Ni, Pb, and Zn contents in the samples from different genetic horizons were chiefly influenced by natural sources, such as soil matrix erosion and weathering, while the concentrations of Cd and Hg were largely affected by anthropogenic activities, specifically coal combustion and agriculture. Conversely, the As content was found to be influenced by a combination of both factors. Anthropogenic activities greatly impacted soil heavy metals at various depths within the study area, thereby underscoring the importance of monitoring these heavy metals. The findings gained from this research can give a scientific basis for the potential utilization of purple soil. [ABSTRACT FROM AUTHOR]

This article discusses the finite‐time mixed H∞$$ {H}_{\infty } $$ and passive filtering design problem for uncertain nonlinear singular systems. The parameter uncertainties are constrained by well‐defined upper bounds on their magnitudes. The objective is to design a full‐order filter to ensure that the augmented singular system to be finite‐time boundedness(FTB) with H∞$$ {H}_{\infty } $$ and passivity performance. Firstly, a sufficient condition for achieving singular finite‐time boundedness with mixed H∞$$ {H}_{\infty } $$ and passivity performance for uncertain nonlinear singular system is derived by introducing a free matrix. Secondly, a novel criterion is established for analyzing finite‐time H∞$$ {H}_{\infty } $$ and passivity problem of filtering error singular system based on augmented matrix technique. Thirdly, the filtering design conditions are presented and the relevant parameters of the desired filter are determined using linear matrix inequality decoupling principle. Finally, a practical circuit system and a numerical example are provided to demonstrate the feasibility of the proposed scheme. [ABSTRACT FROM AUTHOR]

Summary: The underlying intention of this work is to devise a tracking control protocol for the nonlinear cyber‐physical systems that are prone to external disturbances, time‐varying input delays and deception attacks. To be more precise, the modified repetitive tracking controller is formulated for ensuring the asymptotic tracking outcomes of the assayed system with the aim of addressing the impacts caused by external disturbances as well as input time‐varying delays. First of all, the nonlinearities of the investigated cyber‐physical systems are efficaciously approximated by the interval type‐2 fuzzy model approach. Further, the predictor technique is utilized in this study to mitigate the influence of input delays and specifically, the extended Smith predictor approach is employed. That is, the transfer function is inserted into the conventional Smith predictor's main feedback channel. In parallel, the active disturbance rejection technique is executed to reject and estimate the external disturbance impacts on the assayed system. Notably, the improved equivalent‐input‐disturbance estimator approach is tied up and more precisely, the estimated disturbances obtained from the afore‐said estimator are incorporated into the proposed controller. Whilst the deception attacks are characterized as a stochastic distributed random variable that are governed by the Bernoulli distribution. With all of this as a backdrop, the appropriate delay‐dependent constraints are expressed in the context of linear matrix inequalities by employing the Lyapunov stability theory. In line with the predetermined criteria, the relations for computing the required gain matrices are also formulated. Ultimately, the simulation analysis is carried out using two distinct numerical examples to confirm the importance of the proposed control mechanism from the perspective of theory as well as practice. [ABSTRACT FROM AUTHOR]

An anion‐counterion strategy is proposed to construct organic mono‐radical charge‐transfer cocrystals for near‐infrared photothermal conversion and solar‐driven water evaporation. Ionic compounds with halogen anions as the counterions serve as electron donors, providing the necessary electrons for efficient charge transfer with unchanged skeleton atoms and structures as well as the broad red‐shifted absorption (200–2000 nm) and unprecedented photothermal conversion efficiency (~90.5 %@808 nm) for the cocrystals. Based on these cocrystals, an excellent solar‐driven interfacial water evaporation rate up to 6.1±1.1 kg ⋅ m−2 ⋅ h−1 under 1 sun is recorded due to the comprehensive evaporation effect from the cocrystal loading in polyurethane foams and chimney addition, such performance is superior to the reported results on charge‐transfer cocrystals or other materials for solar‐driven interfacial evaporation. This prototype exhibits the great potential of cocrystals prepared by the one‐step mechanochemistry method in practical large‐scale seawater desalination applications. [ABSTRACT FROM AUTHOR]

As a common disease, canker seriously affects the yield and quality of fragrant pear due to the lack of effective control measures. Some fungi have been reported to harbor rich reservoirs of viral resources, and some mycoviruses can be used as biocontrol agents against plant diseases. In this study, 199 isolates were obtained from diseased branches of fragrant pear in the main production areas of Xinjiang. Among them, 134 belonged to Valsa spp., identified using morphological and molecular biological techniques, in which V. mali was the dominant species. The mycoviruses in Valsa spp. were further identified using metatranscriptomic sequencing and RT-PCR. The results revealed that a total of seven mycoviruses were identified, belonging to Botourmiaviridae, Endornaviridae, Fusariviridae, Hypoviridae, Mitoviridae, and Narnaviridae, among which Phomopsis longicolla hypovirus (PlHV) was dominant in all the sample collection regions. The Cryphonectria hypovirus 3-XJ1 (CHV3-XJ1), Botourmiaviridae sp.-XJ1 (BVsp-XJ1), and Fusariviridae sp.-XJ1 (Fvsp-XJ1) were new mycoviruses discovered within the Valsa spp. More importantly, compared with those in the virus-free Valsa spp. strain, the growth rate and virulence of the VN-5 strain co-infected with PlHV and CHV3-XJ1 were reduced by 59% and 75%, respectively, and the growth rate and virulence of the VN-34 strain infected with PlHV were reduced by 42% and 55%, respectively. On the other hand, the horizontal transmission efficiency of PlHV decreased when PlHV was co-infected with CHV3-XJ1, indicating that PlHV and CHV3-XJ1 were antagonistic. In summary, the mycoviruses in Valsa spp. were identified in Xinjiang for the first time, and three of them were newly discovered mycoviruses, with two strains yielding good results. These results will offer potential biocontrol resources for managing pear canker disease and provide a theoretical basis for the control of fruit tree Valsa canker disease. [ABSTRACT FROM AUTHOR]

As a new class of soft materials, continuous emulsion channels have been successfully stabilized solely by rough colloids, which exhibit unique capability in sterically controlling liquid–liquid interfaces. Once jammed at the interface, the roughness‐enhanced frictions can slow down the dynamics of phase separation, and the interlocking behaviors would constrain their relative motions and generate force structures that provide mechanical support for the created emulsions. Ethanol is used to ensure the particles' absorption, whose migration can modify the interfacial tension, and increase the solubility of active ingredients (e.g., curcumin). Applying rough colloids in ethanol‐containing systems opens new pathways toward the generation of novel structures and materials, where the parallel but separate functionalities provided by various phases demonstrate wide‐ranging applications, especially in delivery systems with variably soluble components. [ABSTRACT FROM AUTHOR]

In the present study, we conducted a conjugate heat transfer (CHT) analysis for double-wall cooling with impingement and effusion, incorporating various types of ribs, using the Reynolds-averaged Navier–Stokes (RANS) method and the modified shear stress transport (SST) turbulence closure model (SST-KIC), accounting for the Kato-Launder modification (K), intermittency (I), and crossflow (C) transition effects. We comprehensively discussed the impact of slit type (parallel, inclined, convergent, and divergent), open-area ratio (β = 5%, 20%, and 40%), and jet Reynolds number on the turbulent flow and heat transfer in a double-wall cooling with slit ribs. Our findings indicated that the introduction of slit ribs significantly improved heat transfer and its uniformity on the target wall, albeit with a slight increase in pressure loss. The overall Nusselt number and thermal-hydraulic performance (THP) in cases with slit ribs gradually decreased with β, yet remained up to 17% and 13% higher than those observed on a smooth target wall. Notably, the open-area ratio of the slit rib exhibited a more pronounced effect on heat transfer over the target plate. For the divergent slit rib within the Reynolds number range of 4000–16 000, the heat transfer enhancement ratio reached the highest value at β of 0.05. In addition, we computed the entropy production caused by fluid friction and heat transfer, as well as the overall entropy production in double-wall cooling at different β and Re. The analysis revealed that the slit rib target plate performed better than the solid rib target plate, showing a distinct advantage in terms of total entropy production. [ABSTRACT FROM AUTHOR]

Simple Summary: Lactation is an intriguing reproductive behavior in pigeons, both male and female pigeons participate in crop milk secretion and contribute to the care of their offspring through the division of labor. The question of whether the metabolism and formation of pigeon milk in both males and females follow the same mechanism is an interesting scientific question. We integrated lactation-associated metabolomic and transcriptomic data from the crop tissues of male and female pigeons during the reproductive cycles. We identified a total of 1413 metabolites across 18 crop tissues. During the reproductive cycles, the concentrations of estrone, L-ergothioneine, and L-histidine exhibited the most dynamic changes in females, while estrone, L-anserine, 1-methylhistidine, homovanillate, oxidized glutathione, and reducing glutathione showed the most dynamic changes in males. Through screening DAMs and DEGs, our findings revealed gender-specific differences in the metabolome and gene expressions, with several metabolites and pathways showing significant variations between males and females. Our findings shed light on the distinct modulation of pigeon crop milk metabolism between males and females and provide insights into the potential functions of male and female pigeon milk in the growth, development, and immunity of young pigeons. Lactation is a unique reproductive behavior in pigeons, with the crop serving as the organ responsible for secreting pigeon milk. Both male and female pigeons can produce crop milk and rear their offspring through a division of labor. Since the time of the secretion of pigeon crop milk is different in the process of feeding the young, whether the metabolism and formation of pigeon milk use the same mechanism is a very interesting scientific question. However, the metabolic dynamics and underlying genetic mechanisms involved in the formation of pigeon crop milk remain unclear, particularly during the incubation–feeding reproductive cycle. In this study, we integrated lactation-associated metabolism and transcriptome data from the crop tissues of both male and female pigeons during the brooding and feeding stages. We mapped the changes in metabolites related to milk formation in the crop tissues during these stages. Through metabolome profiling, we identified 1413 metabolites among 18 crop tissues. During the breeding cycles, the concentrations of estrone, L-ergothioneine, and L-histidine exhibited the most dynamic changes in females. In contrast, estrone, L-anserine, 1-methylhistidine, homovanillate, oxidized glutathione, and reducing glutathione showed the most dynamic changes in males. Gender-specific differences were observed in the metabolome, with several metabolites significantly differing between males and females, many of which were correlated with cytokine binding, immunity, and cytochrome P450 activity. Using this dataset, we constructed complex regulatory networks, enabling us to identify important metabolites and key genes involved in regulating the formation of pigeon milk in male and female pigeons, respectively. Additionally, we investigated gender-associated differences in the crop metabolites of pigeons. Our study revealed differences in the modulation of pigeon crop milk metabolism between males and females and shed light on the potential functions of male and female pigeon milk in the growth, development, and immunity of young pigeons, an area that has not been previously explored. In conclusion, our results provide new insights into the metabolic regulation of pigeon crop milk formation during the brooding and breeding stages. Furthermore, our findings lay the foundation for the accurate development of artificial pigeon milk. [ABSTRACT FROM AUTHOR]