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On the time-varying correlations between oil-,gold-,and stock markets:The heterogeneous roles of policy uncertainty in the US and China

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Petroleum Science 2022年第3期19卷 1420-1432页

作者： Wen Zhao yu-dong Wang School of Economics and Management Nanjing University of Science and TechnologyNanjing210094China

This paper investigates the effects of economic policy uncertainty(EPU)and monetary policy uncertainty(MPU)in the US and China on oil-stock and gold-stock correlations.A quantile regression approach is employed to analyze the heterogeneous impacts under different market correlation *** findings suggest that the“US impact”prevails across all market correlations in the sample,while“China impact”is found for oil-stock ***,the impacts of EPU and MPU on correlations of different asset pairs exhibit heterogeneity in direction and in different correlation *** and MPU have homogenously negative effects on gold-stock correlations across various correlation ***,in terms of oil-stock correlations,they exhibit more significant and stronger positive impacts in the medium and high correlation regime than in the low correlation *** can provide a better diversification for stock market risks than crude oil during the period of high level of economic uncertainty.

关键词： Policy uncertainty Crude oil Gold Cross-asset correlations Quantile regression

A multifractal model for linking Lagrangian and Eulerian velocity structure functions

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Acta Mechanica Sinica 2014年第4期30卷 480-484页

作者： yu-Feng dong Guo-dong Jin LNM Institute of MechanicsChinese Academy of Sciences

A multifractal model is developed to connect the Lagrangian multifractal dimensions with their Eulerian counterparts. We propose that the characteristic time scale of a Lagrangian quantity should be the Lagrangian time scale, and it should not be the Eulerian time scale which was widely used in previous studies on Lagrangian statistics. Using the present model, we can obtain the scaling exponents of Lagrangian velocity structure functions from the existing data or models of scaling exponents of Eulerian velocity structure functions. This model is validated by comparing its prediction with the results of experiments, direct numerical simulations, and the previous theoretical models. The comparison shows that the proposed model can better predict the scaling exponents of Lagrangian velocity structure functions, especially for orders larger than 6.

关键词： Lagrangian multifractal - Eulerian multifractal -Intermittency . Velocity structure functions

Investigation on the vortical structures by the Liutex method in turbulent channels at Re_(τ)=180 with scalloped and triangular riblet control

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Journal of Hydrodynamics 2024年第1期36卷 35-52页

作者： Zhang-dan yu Shang Jiang Hai-dong yu Bi-yu Pang Xin dong Yi-qian Wang School of Mathematical Sciences Soochow UniversitySuzhou215006China Beijing Institute of Astronautical System Engineering Beijing100076China

Riblets are a series of small protrusions formed along the flow direction,which have been extensively studied as a passive turbulent drag reduction *** and numerical simulations have shown that well-designed riblets can significantly reduce drag in turbulent flows,making them highly promising and valuable for various *** this study,we focus on a scalloped riblet,which is designed by smoothly connecting two third-order polynomials,and thus the sharpness of the tip and the curvature of the valley can be well *** conduct direct numerical simulations of turbulent channel with smooth plate,scalloped riblet-mounted and triangular riblet-mounted *** in wall units of W^(+)=20 and height-width ratio ofγ=0.5 are selected for both riblet *** with the smooth plate case,the scalloped riblet case achieves an 8.68%drag reduction,while the triangular riblet case achieves a 4.79%drag *** obtained drag reduction rate of the triangular riblet is consistent with previous experiments and simulations,and the results indicate that the scalloped riblet is more effective in reducing drag and deserves further *** compare turbulent statistics of the scalloped riblet case with those of the triangular riblet *** mean velocity profiles of riblets are similar,but both the Reynolds shear stress and second-order statistics of velocity fluctuations and Liutex are significantly reduced in the scalloped riblets controlled turbulent channel,indicating that the scalloped riblet can more effectively suppress the spanwise and wall-normal turbulent intensity near the *** also compare the pre-multiplied spectra of streamwise velocity and streamwise Liutex component for the three cases to investigate the energy distribution and characteristics of Liutex *** Liutex vortex identification method is also utilized to analyze the instantaneous flow field,which provides insights into the flow field and could be bene

关键词： Liutex vector riblet drag reduction tip sharpness turbulent channel scalloped

Study of Nucleon Unpolarized Structure Functions

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Communications in Theoretical Physics 2008年第3期49卷 725-728页

作者： dong yu-Bing Institute of High Energy Physics the Chinese Academy of Sciences Beijing 100049 China

Nucleon unpolarized structure functions in the ep elastic scattering are discussed. A new unpolarized structure function F^-3 due to the two-photon-exchange is given. Numerical results of the new structure function in... 详细信息

关键词： ep elastic scattering two-photon-exchange structure functions

Solubility of CO_(2) in nonaqueous system of 2-(butylamino)ethanol with 2-butoxyethanol:Experimental data and model representation

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Chinese Journal of Chemical Engineering 2022年第1期35卷 441-448页

作者： yu dong Tiantian Ping Shufeng Shen School of Chemical and Pharmaceutical Engineering Hebei University of Science and TechnologyShijiazhuang 050018China

Nonaqueous amine-based system is an attractive solution to overcome high-energy-intensive CO_(2) capture process using the conventional aqueous *** nonaqueous absorbent of 2-(butylamino)ethanol(BAE)with 2-butoxyethanol(2-BE)has been recently proposed for low-energyconsumption CO_(2) *** this work,Henry’s law constants of CO_(2) in the BAE/2-BE blend were obtained by N_(2)O/CO_(2) analogy,and correlated in the temperature range of(283–333)***-liquid equilibrium(VLE)data for the BAE+CO_(2)+2-BE system at 65.4%(mass)BAE were also determined in a stirred equilibrium cell at temperatures of(313–393)K and CO_(2) partial pressures up to 275 kPa.A single apparent equilibrium constant KCO_(2);app was proposed for this system and correlated as a function of temperature,carbonated degree of amine and CO_(2) *** data were well represented by the modified Kent-Eisenberg model with an average absolute relative deviation(AARD)of 13%.

关键词： Solubility CO_(2)capture Nonaqueous absorbent 2-(Butylamino)ethanol 2-Butoxyethanol Model

Study of Electric Polarizabilities of Nucleon with a Constituent Quark Model and Pion Meson Cloud

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Communications in Theoretical Physics 2006年第5期45卷 885-888页

作者： dong yu-Bing Institute of High Energy Physics the Chinese Academy of Sciences Beijing 100049 China

In this work, a subtle role of the pion meson cloud effect on the electric polarizabilities of the proton and neutron is stressed. It is shown that the electric polarizabilities of the proton and neutron, and the difference between the electric polarizabilities of the proton and neutron can be explained by including the pion meson cloud explicitly. However, the magnitude of the estimated mean-square charge radius of the neutron is still far from the measurement.

关键词： electric polarizability pion meson cloud charge radius

THE NONLINEAR BEHAVIOR OF INTERFACE BETWEEN TWO-PHASE SHEAR FLOW WITH LARGE DENSITY RATIOS

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Journal of Hydrodynamics 2006年第5期18卷 587-592页

作者： dong yu-hong Shanghai Institute of Applied Mathematics and Mechanics Shanghai University Shanghai 200072 China

The Navier-Stokes equations for the two-dimensional incompressible flow are used to investigate the effects of the Reynolds number and the Weber number on the behavior of interface between liquid gas shear flow. In the present study, the density ratios are fixed at approximately 10^0-10^3. The interface between the two phases is resolved using the level-set approach. The Reynolds number and the Weber number, based on the gas, are selected as 400-10000 and 40-5000, respectively. In the past, simulations reappeared the amplitude of interface growth predicted by viscous Orr-Sommerfeld linear theory, verifying the applicability and accuracy of the numerical method over a wide range of density and viscosity ratios; now, the simulations show that the nonlinear development of ligament elongated structures and resulted in the subsequent breakup of the heavier fluid into drops.

关键词： two-phase shear flow large density ratios immiscible interface level set approach

Contrastive Self-supervised Representation Learning Using Synthetic Data

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International Journal of Automation and computing 2021年第4期18卷 556-567页

作者： dong-yu She Kun Xu Beijing National Research Center for Information Science and Technology Department of Computer Science and TechnologyTsinghua UniversityBeijing 100084China

Learning discriminative representations with deep neural networks often relies on massive labeled data, which is expensive and difficult to obtain in many real scenarios. As an alternative, self-supervised learning that leverages input itself as supervision is strongly preferred for its soaring performance on visual representation learning. This paper introduces a contrastive self-supervised framework for learning generalizable representations on the synthetic data that can be obtained easily with complete ***, we propose to optimize a contrastive learning task and a physical property prediction task simultaneously. Given the synthetic scene, the first task aims to maximize agreement between a pair of synthetic images generated by our proposed view sampling module, while the second task aims to predict three physical property maps, i.e., depth, instance contour maps, and surface normal maps. In addition, a feature-level domain adaptation technique with adversarial training is applied to reduce the domain difference between the realistic and the synthetic data. Experiments demonstrate that our proposed method achieves state-of-the-art performance on several visual recognition datasets.

关键词： Self-supervised learning contrastive learning synthetic image convolutional neural network representation learning

Provenance of upper Permian-lowermost Triassic sandstones, Wutonggou low-order cycle, Bogda Mountains, NW China:implications on the unroofing history of the Eastern North Tianshan Suture

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Journal of Palaeogeography 2020年第3期9卷 314-334页

作者： dong-yu Zheng Wan Yang Geology and Geophysics Program Missouri University of Science and TechnologyRollaMO 65409USA

This study investigates the provenance of sedimentary rocks in Bogda Mountains, NW China, and reconstructs the lithology and unroofing history of the Eastern North Tianshan Suture. Petrographic point counting data of sandstones and compositions of conglomerates of upper Permian-lowermost Triassic Wutonggou low-order cycle from Zhaobishan, North Tarlong, Taodonggou, and Dalongkou sections in the southern and northern foothills of Bogda Mountains were used to interpret the temporal and spatial variations of lithology of the Eastern North Tianshan Suture, which is the sediment source area. Three compositional trends were identified. A trend of upwardincreasing quartz content and granitic pebbles in Zhaobishan section suggests a change from the undissected volcanic arc, accretionary wedge and trench setting to predominantly transitional volcanic arc and subordinate accretionary wedge and trench, in the eastern part of the Eastern North Tianshan Suture. In North Tarlong and Taodonggou sections, however, the lithic content decreases and the contents of quartz and granitic pebbles increase up sections. These trends indicate that the western part of the Eastern North Tianshan Suture changed from an undissected volcanic arc to the transitional volcanic arc, accretionary wedge and trench. No clear trend in the lithic-rich sandstones of the Dalongkou section indicates that sediments were derived from the undissected volcanic arc in the Eastern North Tianshan Suture and local rift shoulders. Compositional variations of studied rocks suggest that the Eastern North Tianshan Suture was an amalgamated complex with great spatial and temporal heterogeneities in lithology and experienced persistent unroofing during late Permian-earliest Triassic. This study reconstructs a key element of the Chinese Tianshan Suture and serves as an example to understand the unroofing processes of ancient sutures.

关键词： Provenance Wutonggou low-order cycle Bogda Mountains Unroofing Eastern North Tianshan Suture NW China