Multiple root resonance of tandem mill

The multiple-root resonance theory is introduced. The multiple-root resonance region is defined, and it includes the sub-multiple-root resonance region and complete-multiple-root resonance region. It is proved that the vibration mode shapes are identical if the natural frequencies are similar in size. The dynamic analysis of the 3-DOF model is investigated, and the results show that the variations of the mass ratio and stiffness ratio induce the natural frequencies approaching and forming a multiple-root resonance. The dynamic analysis of the tandem mill is made to study the multiple-root vibration, and the results show that with the increase in mass ratio, the 6th and 7th-order natural frequencies continue approaching one another and converge at the 5th-order natural frequency. The finite element analysis of the rolling mill shows that there are two similar natural frequencies in the rolling mill, and the vibration modes are not identical but have large vertical-component vibrations. The field test shows that the multiple-root resonance occurs in the tandem mill; after the foundation reconstruction, the multiple-root resonance is replaced by resonance with one dominant frequency, and the vibration is reduced

Research on vertical vibration of hot rolling mill under screw-down-strip combined excitation

In this paper, we find the violent vibration of the hot rolling mill is induced by the combination of the screw-down system and the strip, explain how the srew-down-strip combined excitation effects the rolling mill, and introduce an effective method to restrain the vibration. First, two experiments, stripless rolling and turning off the screw-down system, are conducted, the first experiment simulates the rolling process without strip and the second experiment simulates the rolling process without the screw-down system, the results indicate that the rolling mill vibration is induced by the srew-down-strip combined excitation. Then, to explain this phenomenon, the mathematical model of the rolling mill under screw-down-strip combined excitation is proposed, we find that few excitation frequency components can induce more response frequency components, therefore it’s more possible to approach the natural frequency of the rolling mill. Finally, a vibration suppression method is introduced by eliminating some specified frequency components of the screw-down system with a filter, and the result shows that the vibration decreased by 98.7 %

Bis[μ-1,2-diphenyl-N,N′-bis­(di-2-pyridyl­methyl­eneamino)ethane-1,2-diimine]disilver(I) bis­(hexa­fluorido­phosphate) acetonitrile disolvate

In the centrosymmetric dinuclear title compound, [Ag2(C36H26N8)2](PF6)2·2C2H3N, the Ag+ ion is bound to four N atoms from two 1,2-diphenyl-N,N′-bis­(di-2-pyridyl­methyl­eneamino)ethane-1,2-diimine ligands in a distorted tetra­hedral geometry. The ligand adopts a twist conformation, coordinating two metal centers by three pyridyl N atoms and one imine N atom and spanning two Ag+ ions, resulting in the formation of a helical dimeric structure

Leveraging natural cognitive systems in conjunction with ResNet50-BiGRU model and attention mechanism for enhanced medical image analysis and sports injury prediction

IntroductionIn this study, we explore the potential benefits of integrating natural cognitive systems (medical professionals' expertise) and artificial cognitive systems (deep learning models) in the realms of medical image analysis and sports injury prediction. We focus on analyzing medical images of athletes to gain valuable insights into their health status.MethodsTo synergize the strengths of both natural and artificial cognitive systems, we employ the ResNet50-BiGRU model and introduce an attention mechanism. Our goal is to enhance the performance of medical image feature extraction and motion injury prediction. This integrated approach aims to achieve precise identification of anomalies in medical images, particularly related to muscle or bone damage.ResultsWe evaluate the effectiveness of our method on four medical image datasets, specifically pertaining to skeletal and muscle injuries. We use performance indicators such as Peak Signal-to-Noise Ratio and Structural Similarity Index, confirming the robustness of our approach in sports injury analysis.DiscussionOur research contributes significantly by providing an effective deep learning-driven method that harnesses both natural and artificial cognitive systems. By combining human expertise with advanced machine learning techniques, we offer a comprehensive understanding of athletes' health status. This approach holds potential implications for enhancing sports injury prevention, improving diagnostic accuracy, and tailoring personalized treatment plans for athletes, ultimately promoting better overall health and performance outcomes. Despite advancements in medical image analysis and sports injury prediction, existing systems often struggle to identify subtle anomalies and provide precise injury risk assessments, underscoring the necessity of a more integrated and comprehensive approach

A Novel Circulating Current Suppression for Paralleled Current Source Converter Based on Virtual Impedance Concept

The circulating current is one of the important issues for parallel converters. It affects the system stable operation and degrades the power quality. In order to reduce the circulating current of the parallel converter and reduce the harmonic pollution to the power grid, a new circulating current suppression strategy is proposed for the parallel current source converter without any communication line. This strategy is able to realize the current sharing between parallel modules by changing the external characteristics of the parallel modules to thus suppress the circulating current among the parallel current source converters. The proposed control strategy adopts DC-side droop control and AC-side virtual impedance control. The DC-side droop control is used to generate the reference voltage of each parallel module, while the AC-side virtual impedance is used to the circulating current suppression. We performed a time domain test of the parallel converter, and the results show that the proposed control strategy reduced the RMS circulating current of the parallel converter by 50% and effectively reduced the grid-side current THD while ensuring the stable operation of the converter. The effectiveness of the proposed control strategy was, therefore, verified

Jinhong Tablet Reduces Damage of Intestinal Mucosal Barrier in Rats with Acute Biliary Infection via Bcl-2/Bax mRNA and Protein Regulation

Objective. To explore the effects and mechanism of Jinhong Tablet on intestinal mucosal barrier function and SIRS in rats with acute biliary infection. Methods. 36 SD male rats were divided into three groups: sham operation (control), acute biliary infection (ABI) model, and Jinhong Tablet (Jinhong) group. Jinhong group were force-fed with Jinhong Tablet, while the other two groups received oral saline. At days 3 and 5, morphological changes of intestinal mucosa were assessed. Serum diamine oxidase (DAO), D-lactate, and endotoxin levels were measured. And the genes bcl-2 and bax in intestinal tissues were tested by real-time PCR and Western blotting. Results. Intestinal damage was significantly less severe in Jinhong group compared with ABI group, as indicated by Chiu’s scoring, TUNEL analysis, and serum DAO, D-lactic acid, and endotoxin levels. Additionally, the expression of bax mRNA and protein was decreased and the ratio of bcl-2/bax mRNA and protein was increased compared with ABI group. Conclusion. Jinhong Tablet had a positive intervention on acute biliary infection through improving inflammation and intestinal mucosal barrier, inhibiting excessive apoptosis of intestinal epithelial cells via bax and bcl-2 gene, and protein regulation

DISCO:Interference-Aware Distributed Cooperation with Incentive Mechanism for 5G Heterogeneous Ultra-Dense Networks

Interference and traffic imbalance hinder improved system performance in heterogeneous ultra-dense networks. Network cooperation has become a promising paradigm with sophisticated techniques that can significantly enhance performance. In this article, a coalition game-theoretic framework is introduced to characterize cooperative behaviors, thus exploring these cooperative benefits and diversity gains. First, we introduce the basis of the coalition games. Then we survey its latest applications, in particular, interference mitigation and traffic offloading. Different from most current applications, we concentrate on cooperative incentive mechanism design since node cooperation always means resource consumption and other costs. Moreover, for the incentive mechanism, cooperative spectrum leasing is introduced. To mitigate interference and balance traffic, we propose two schemes under the presented framework: IASL and TOSL. Simulation results show the improved performance of the cooperative gains using the proposed IASL and TOSL schemes