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The study on the shrink-fit multi-ring flywheel with fall-off function

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Nuclear Science and Techniques 2017年第3期28卷 115-122页

作者： Yu-Jin Wang De-Zhong Wang Wei-Zhong Guo jun-lian yin Cheng-Wei Wang School of Mechanical Engineering Shanghai Jiao Tong University Shanghai 200240 China Dalian Clean Energy Heavy Industrial Co. LTDDalian 116630 China

Structural integrity of the flywheel of reactor coolant pump is important for safe operation of a nuclear power plant. A shrink-fit multi-ring flywheel is designed with a fall-off function, i.e., it will separate from the shaft at a designed fall-off rotation speed, which is determined by the assembly process and the gravity. However, the two factors are ignored in the analytical method based on the Lame's equation. In this work, we conducted fall-off experiments to analyze the two factors and used the experimental data to verify the validity of the analytical method and the finite element method(FEM). The results show that FEM performs better than the analytical method in designing the falloff function of the flywheel, though FEM cannot successfully predict the strain variation with the rotational speed.

关键词： Multi-ring flywheel Fall-off rotational speed Shrink-fit assembly Gravity

Large eddy simulation of unsteady flow in gas-liquid separator applied in thorium molten salt reactor

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Nuclear Science and Techniques 2018年第5期29卷 10-18页

作者： Jing-Jing Li Ya-Lan Qian jun-lian yin Hua Li Wei Liu De-Zhong Wang School of Mechanical Engineering Shanghai Jiao Tong UniversityShanghai 200240China Shanghai Institute of Applied Physics Shanghai 201800China

Axial gas-liquid separators have been adopted in fission gas removal systems for the development of thorium molten salt reactors. In our previous study, we observed an unsteady flow phenomenon in which the flow pattern is directly dependent on the backpressure in a gas-liquid separator; however, the underlying flow mechanism is still unknown. In order to move a step further in clarifying how the flow pattern evolves with a variation in backpressure, a large eddy simulation(LES) was adopted to study the flow field evolution. In the simulation, an artificial boundary was applied at the separator outlet under the assumption that the backpressure increases linearly. The numerical results indicate that the unsteady flow feature is captured by the LES approach, and the flow transition is mainly due to the axial velocity profile redistribution induced by the backpressure variation. With the increase in backpressure,the axial velocity near the downstream orifice transits from negative to positive. This change in the axial velocity sign forces the unstable spiral vortex to become a stable rectilinear vortex.

关键词： Swirl flow Thorium molten salt reactor Computational fluid dynamics Large eddy simulation

Impact of right upper pulmonary vein isolation on atrial vagal innervation and vulnerability to atrial fibrillation

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Chinese Medical Journal 2006年第24期119卷 2049-2055页

作者： LIU Yuan ZHANG Shu-long DONG ying-xue ZHAO Hong-wei GAO lian-jun yin Xiao-meng LI Shi-jun LIN Zhi-hu YANG Yan-zong Department of Cardiology First Affiliated Hospital of Dalian Medical University Dalian 116011 China

Background Based on the hypothesis that pulmonary vein isolation could result in the damage of the epicardial fat pads, this study aimed to investigated the impact of right upper pulmonary vein （RUPV） isolation on vagal innervation to atria. Methods Bilateral cervical sympathovagal trunks were decentralized in 6 dogs. Metoprolol was given to block sympathetic effects. Multipolar catheters were placed into the right atrium （R.A） and coronary sinus （CS）. RUPV isolation was performed via transseptal procedure. Atrial effective refractory period （ERP）, vulnerability window （VW） of atrial fibrillation （AF）, and sinus rhythm cycle length （SCL） were measured at RA and distal coronary sinus （CSd） at baseline and vagal stimulation before and after RUPV isolation. Serial sections of underlying tissues before and after ablation were stained with haematoxylin and eosin. Results SCL decreased significantly during vagal stimulation before RUPV isolation （197±21 vs 13±32 beats per minute, P〈0.001）, but remained unchanged after RUPV isolation （162±29 vs 140±39 beats per minute, P〉0.05）. ERP increased significantly before RUPV isolation compared with that during vagal stimulation [（85.00±24.29） ms vs （21.67±9.83） ms at RA, P〈0.001; （90.00± 15.49） ms vs （33.33±25.03） ms at CSd P〈0.005], but ERP at baseline hardly changed after RUPV isolation compared with that during vagal stimulation [（103.33 ± 22.50） vs （95.00± 16.43） ms at RA, P = 0.09; （98.33±24.83） vs （75.00±29.50） ms at CSd, P=0.009]. The ERP shortening during vagal stimulation after RUPV isolation decreased significantly [（63.33 ±22.51） ms vs （8.33 ± 9.83） ms at RA, P〈0.005; （56.67±20.66） ms vs （23.33± 13.66） ms at CSd, P〈0.05]. AF was rarely induced at baseline before and after RUPV isolation （VW close to 0）, while VW of AF to vagal stimulation significantly decreased after RUPV isolation [（40.00± 10.95） vs 0 ms at RA, P〈0.001; （45.00±32.09） vs （15.00±23.45） ms at CS, P 〈0.05]. The architecture of individual ganglia was signi

关键词： atrial fibrillation pulmonary vein vagus

Discovery of a new family member of arsenic–vanadium polyoxometalates with high catalytic performance for one-pot coupling of CO2, epoxides and amines

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Tungsten 2025年第1期7卷 80-87页

作者： Fang-Qian Wang yin Zhang Wei-Wei Wang Mei-Qian Fu Hong-Bing Mo Wei-Dong Yu Chao Liu jun Yan College of Chemistry and Chemical Engineering Central South University junior Education Department Changsha Normal University School of Science Hunan University of Technology and Business

Arsenic-vanadium polyoxometalates（POMs） represent a family of tremendous potential catalysts owing to their peculiar physical and chemical *** in CO2conversion,using POMs to catalyze the conversion of CO2and epoxide into chemical intermediates is the research ***,A new family number of arsenic-vanadium POMs,[N（CH3）4]4[As8V12O38（H2O）]·2H2O({As8V12O38}),was reported and characterized by single-crystal X-ray diffraction,fourier transform infrared spectroscopy,X-ray photoelectron spectroscopy,*** from other allotropicity,{As8V12O38}shows a different structure pattern with an I-43d *** obtained {As8V12O38} was employed as a catalyst for the *** initial catalytic reaction confirmed that {As8V12O38} can catalyze the formation of epoxy carbonate by using 1.01 kPa CO2and epoxide at 70℃.Furtherly,when added amine in the catalytic system,oxazolidinone could be obtained by high yields,which provides an efficient way to convert CO2into profitable ***,a possible catalytic reaction mechanism was proposed by using different characterization analyses.{As8V12O38} first catalyzes the epoxide and CO2to form an epoxy carbonate and then catalyzes epoxy carbonate and benzylamine into oxazolidinone.

关键词： Arsenic CO2 conversion Oxazolidinone Polyoxometalates Vanadium

Effect of order–disorder transition on thermodynamic and electronic properties of σ and χ phases in W–Re alloy: the first-principles calculation

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Tungsten 2025年第1期7卷 195-213页

作者： Zhi-Peng Zhu Dian Jia William Yi Wang jun-Lei yin Xing-Yu Gao Shu-Feng Yang Hai-Feng Song Jin-Shan Li State Key Laboratory of Solidification Processing Northwestern Polytechnical University Laboratory of Computational Physics Institute of Applied Physics and Computational Mathematics School of Metallurgical and Ecological Engineering University of Science and Technology Beijing

The Tungsten-Rhenium(W-Re) alloys,celebrated for their high melting point,strength at elevated temperatures,electrical resistivity,and radiation resistance,have been widely utilized in high-temperature components,aerospace,electronics,and nuclear *** constituents of the topologically close-packed(TCP) phases,the sigma phase(σ) and chi phase(χ) formed within W-Re alloys wield considerable influence on the mechanical properties and the stability of the *** calculations were utilized in the present work to explore the structural,thermodynamic,and electronic properties of both ordered and disordered configurations within the σ and χ phases,culminating in a systematic elucidation of the higher phase stability exhibited by the ordered *** is found that the bulk modulus of these two phases is directly proportional to the concentration of Re in the alloy,while the equilibrium volume is inversely *** thermodynamic parameters of the σ and χ phases are calculated via the mean-field potential *** similar trends observed in the isobaric heat capacity,enthalpy increment,and entropy change curves for these two phases suggest they possess comparable thermodynamic *** is noteworthy that the contribution of ionic vibrations predominantly affects the isobaric heat capacity,while the contribution of thermal electronic excitations increases linearly with *** the structure and thermodynamic properties of TCP phases in W-Re alloys at low temperatures has profound significance for optimizing material performance,microstructures features,establishing theoretical foundations,and predicting material behavior.

关键词： First-principles calculations Phase stability TCP phases Thermodynamic properties W–Re alloy

The composition of magmatic-hydrothermal fluids and their related metal mineralization

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Science China Earth Sciences 2025年第1期68卷 208-225页

作者： Qihai SHU jun DENG State Key Laboratory of Geological Processes and Mineral Resources School of Earth Sciences and Resources China University of Geosciences Frontiers Science Center for Deep-time Digital Earth China University of Geosciences

Magmatic hydrothermal deposits are important sources of many bulk, precious, and rare metals, and have attracted interest from both academic and industrial communities. However, it is still unclear if the major enrichment of the ore-forming metals occurs in the parental magma source region, during the magma evolution, or after the fluid exsolution. Fluid inclusions trapped in hydrothermal minerals crystallized in the early, high-temperature stage before metal precipitation record information close to that of the initially exsolved magmatic fluids, which are helpful in revealing whether the metals have been already significantly enriched prior to the hydrothermal stage. In this study, available compositional data of such early-stage fluid inclusions from magmatic hydrothermal systems globally have been compiled. The results indicate that the concentrations of Cu,Sn, and W respectively from the Cu-, Sn-, and W-mineralized fluids are significantly higher than the hydrothermal systems that do not produce ores with the corresponding metals. This suggests that Cu, Sn, and W could have already been enriched in the magma source and/or magma evolution stage. The Mo concentrations show no difference between Mo-mineralized and Mobarren fluid systems, indicating no significant pre-enrichment in the source region or during the magma evolution. This also implies that an efficient collection of Mo from a large volume of magmas is required to account for the formation of a large Mo deposit. Almost all the hydrothermal fluids contain high concentrations of Fe and Zn-Pb, but only a few of them eventually form Fe or Zn-Pb deposits, reflecting an important role of the hydrothermal evolution process on the selective metal *** above results indicate that different metals are enriched in different stages of a magmatic hydrothermal system, and that the major roles played in the formation of a deposit vary with the metal types. In addition to the metal concentrations in the o

关键词： Magmatic hydrothermal deposits Fluid inclusions LA-ICP-MS Metal enrichment Mineralization mechanism

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Neural Regeneration Research 2025年第2期20卷 366-377页

作者： Samuel Abokyi Dennis Yan-yin Tse School of Optometry The Hong Kong Polytechnic UniversityKowloonHong Kong Special Administrative RegionChina Research Center for SHARP Vision The Hong Kong Polytechnic UniversityKowloonHong Kong Special Administrative RegionChina Center for Eye and Vision Research Sha TinHong Kong Special Administrative RegionChina

Retinal aging has been recognized as a significant risk factor for various retinal disorders,including diabetic retinopathy,age-related macular degeneration,and glaucoma,following a growing understanding of the molecular underpinnings of their *** comprehensive review explores the mechanisms of retinal aging and investigates potential neuroprotective approaches,focusing on the activation of transcription factor *** meta-analyses have demonstrated promising outcomes of transcription factor EB-targeted strategies,such as exercise,calorie restriction,rapamycin,and metformin,in patients and animal models of these common retinal *** review critically assesses the role of transcription factor EB in retinal biology during aging,its neuroprotective effects,and its therapeutic potential for retinal *** impact of transcription factor EB on retinal aging is cell-specific,influencing metabolic reprogramming and energy homeostasis in retinal neurons through the regulation of mitochondrial quality control and nutrient-sensing *** vascular endothelial cells,transcription factor EB controls important processes,including endothelial cell proliferation,endothelial tube formation,and nitric oxide levels,thereby influencing the inner blood-retinal barrier,angiogenesis,and retinal ***,transcription factor EB affects vascular smooth muscle cells,inhibiting vascular calcification and *** retinal pigment epithelial cells,transcription factor EB modulates functions such as autophagy,lysosomal dynamics,and clearance of the aging pigment lipofuscin,thereby promoting photoreceptor survival and regulating vascular endothelial growth factor A expression involved in *** cell-specific functions of transcription factor EB significantly impact retinal aging mechanisms encompassing proteostasis,neuronal synapse plasticity,energy metabolism,microvasculature,and inflammation,ultimately offering pro

关键词： age-related macular degeneration anti-aging interventions autophagy calorie restriction diabetic retinopathy exercise glaucoma neuromodulation phagocytosis photoreceptor outer segment degradation retinal aging transcription factor EB

DKP-SLAM:A Visual SLAM for Dynamic Indoor Scenes Based on Object Detection and Region Probability

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Computers, Materials & Continua 2025年第1期82卷 1329-1347页

作者： Menglin yin Yong Qin Jiansheng Peng College of Automation Guangxi University of Science and TechnologyLiuzhou545000China Department of Artificial Intelligence and Manufacturing Hechi UniversityHechi546300China Key Laboratory of AI and Information Processing Education Department of Guangxi Zhuang Autonomous RegionHechi546300China Guangxi Key Laboratory of Sericulture Ecology and Applied Intelligent Technology School of Chemistry and BioengineeringHechi UniversityHechi546300China

In dynamic scenarios,visual simultaneous localization and mapping(SLAM)algorithms often incorrectly incorporate dynamic points during camera pose computation,leading to reduced accuracy and *** paper presents a dynamic SLAM algorithm that leverages object detection and regional dynamic ***,a parallel thread employs the YOLOX object detectionmodel to gather 2D semantic information and compensate for missed ***,an improved K-means++clustering algorithm clusters bounding box regions,adaptively determining the threshold for extracting dynamic object contours as dynamic points *** process divides the image into low dynamic,suspicious dynamic,and high dynamic *** the tracking thread,the dynamic point removal module assigns dynamic probability weights to the feature points in these *** with geometric methods,it detects and removes the dynamic *** final evaluation on the public TUM RGB-D dataset shows that the proposed dynamic SLAM algorithm surpasses most existing SLAM algorithms,providing better pose estimation accuracy and robustness in dynamic environments.

关键词： Visual SLAM dynamic scene YOLOX K-means++clustering dynamic probability

Research on Stock Price Prediction Method Based on the GAN-LSTM-Attention Model

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Computers, Materials & Continua 2025年第1期82卷 609-625页

作者： Peng Li Yanrui Wei Lili yin College of Computer Science and Technology Harbin University of Science and TechnologyHarbin150006China

Stock price prediction is a typical complex time series prediction problem characterized by dynamics,nonlinearity,and *** paper introduces a generative adversarial network model that incorporates an attention mechanism(GAN-LSTM-Attention)to improve the accuracy of stock price ***,the generator of this model combines the Long and Short-Term Memory Network(LSTM),the Attention Mechanism and,the Fully-Connected Layer,focusing on generating the predicted stock *** discriminator combines the Convolutional Neural Network(CNN)and the Fully-Connected Layer to discriminate between real stock prices and generated stock ***,to evaluate the practical application ability and generalization ability of the GAN-LSTM-Attention model,four representative stocks in the United States of America(USA)stock market,namely,Standard&Poor’s 500 Index stock,Apple Incorporatedstock,AdvancedMicroDevices Incorporatedstock,and Google Incorporated stock were selected for prediction experiments,and the prediction performance was comprehensively evaluated by using the three evaluation metrics,namely,mean absolute error(MAE),root mean square error(RMSE),and coefficient of determination(R2).Finally,the specific effects of the attention mechanism,convolutional layer,and fully-connected layer on the prediction performance of the model are systematically analyzed through ablation *** results of experiment show that the GAN-LSTM-Attention model exhibits excellent performance and robustness in stock price prediction.

关键词： Stock price prediction generative adversarial network attention mechanism time-series prediction