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Accurate simulations of pure-viscoacoustic wave propagation in tilted transversely isotropic media

Petroleum Science 2024年第2期21卷 866-884页

作者： Qiang Mao jian-ping Huang Xin-Ru Mu Ji-Dong Yang Yu-jian Zhang Geosciences Department China University of Petroleum(East China)Qingdao266580ShandongChina Pilot National Laboratory for Marine Science and Technology(Qingdao) Qingdao266207ShandongChina

Forward modeling of seismic wave propagation is crucial for the realization of reverse time migration(RTM) and full waveform inversion(FWI) in attenuating transversely isotropic media. To describe the attenuation and anisotropy properties of subsurface media, the pure-viscoacoustic anisotropic wave equations are established for wavefield simulations, because they can provide clear and stable wavefields. However, due to the use of several approximations in deriving the wave equation and the introduction of a fractional Laplacian approximation in solving the derived equation, the wavefields simulated by the previous pure-viscoacoustic tilted transversely isotropic(TTI) wave equations has low accuracy. To accurately simulate wavefields in media with velocity anisotropy and attenuation anisotropy, we first derive a new pure-viscoacoustic TTI wave equation from the exact complex-valued dispersion formula in viscoelastic vertical transversely isotropic(VTI) media. Then, we present the hybrid finite-difference and low-rank decomposition(HFDLRD) method to accurately solve our proposed pure-viscoacoustic TTI wave equation. Theoretical analysis and numerical examples suggest that our pure-viscoacoustic TTI wave equation has higher accuracy than previous pure-viscoacoustic TTI wave equations in describing q P-wave kinematic and attenuation characteristics. Additionally, the numerical experiment in a simple two-layer model shows that the HFDLRD technique outperforms the hybrid finite-difference and pseudo-spectral(HFDPS) method in terms of accuracy of wavefield modeling.

关键词： Pure-viscoacoustic TTI wave equation Attenuation anisotropy Seismic modeling Low-rank decomposition method

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New Wronskian Representation of Solution for a Variable-Coefficient Kadomtsev-Petviashvili Equation

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Chinese Physics Letters 2013年第6期30卷 46-49页

作者： WU jian-ping GENG Xian-Guo Department of Mathematics Zhengzhou University100 Kexue RoadZhengzhou 450001

Utilizing the Wronskian technique,a new Wronskian representation is proposed for a variable-coefficient Kadomtsev–Petviashvili(vcKP)***,some particular forms of Wronskian determinant solutions,includingN-soliton solu... 详细信息

关键词： equation. soliton rational

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Theoretical analysis of non-probabilistic reliability based on interval model

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Acta Mechanica Solida Sinica 2017年第6期30卷 638-646页

作者： Xu-Yong Chen jian-ping Fan Xiao-Ya Bian School of Resource and Civil Engineering Wuhan Institute of Technology School of Civil Engineering & Mechanics Huazhong University of Science and Technology

The aim of this paper is to propose a theoretical approach for performing the nonprobabilistic reliability analysis of *** to a great deal of uncertainties and limited measured data in engineering practice,the structural uncertain parameters were described as interval *** theoretical analysis model was developed by starting from the 2-D plane and 3-D *** order to avoid the loss of probable failure points,the 2-D plane and 3-D space were respectively divided into two parts and three parts for further *** study pointed out that the probable failure points only existed among extreme points and root points of the limit state ***,the low-dimensional analytical scheme was extended to the high-dimensional *** the proposed approach,it is easy to find the most probable failure point and to acquire the reliability index through simple comparison directly.A number of equations used for calculating the extreme points and root points were also *** result was useful to avoid the loss of probable failure points and meaningful for optimizing searches in the research ***,two kinds of examples were presented and compared with the existing *** good agreements show that the proposed theoretical analysis approach in the paper is *** efforts were conducted to improve the optimization method,to indicate the search direction and path,and to avoid only searching the local optimal solution which would result in missed probable failure points.

关键词： Non-probabilistic Reliability Interval model Theoretical analysis Probable failure point

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Evaluation of increasing service life of epoxy zinc-rich coating on 3 wt.%Ni-advanced low-alloy steel in marine atmospheric environment

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Journal of Iron and Steel Research International 2022年第4期29卷 698-706页

作者： Sheng-rong Wang jian-wei Yang jian-ping Cao Shan jiang Fei-fan Xu Shougang Research Institute of Technology of Shougang Group Co. Ltd.Beijing 100043China Beijing Key Laboratory of Green Recyclable Process for Iron&Steel Production Technology Beijing 100043China

The addition of Ni element into steel to prolong the service life of coated steel was investigated in marine atmospheric environment by laboratory simulated accelerated *** scanning electron microscope and electron probe microanalysis combined with electrochemical impedance spectroscopy were used to characterize coated steel properties and examined the anti-corrosion *** results showed that 3 wt.%Ni-advanced steel(3Ni steel)substrate obviously delayed the failure time of coating compared to carbon steel,therefore prolonging the service life of coating on the steel.X-ray diffraction patterns for the corrosion products under the scratched coating on 3Ni steel exhibited that FeNi_(2)O_(4) and Fe_(2)O_(3) occurred in the corrosion product of 3Ni *** was also found that Ni element enriched in the product layer through analyzing the appearance and composition of corrosion products by electron probe *** ions were blocked out of product by the enrichment of Ni element in rust layer.

关键词： 3wt.% Ni-advanced low-alloy steel Coating failure Service life Corrosion product Marine atmosphere

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Grain boundary segregation of minor arsenic and nitrogen at elevated temperatures in a microalloyed steel

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International Journal of Minerals,Metallurgy and Materials 2012年第5期19卷 399-403页

作者： Yuan-zhi Zhu Zhe Zhu jian-ping Xu The Key Laboratory of the Ministry of Education of China for Ferrous Metallurgy and Resources Utilization Wulaan University of Science and Technology Wuhan430081 China School of Materials and Metallurgy Wuhan University of Science and Technology Wuhan 430081 China

Auger electron spectroscopy （AES） was used to investigate the grain boundary segregation of arsenic and nitrogen in a kind of microalloyed steel produced by a compact strip production （CSP） technology at 950 to 1100℃, which are similar to the hot working temperature of the steel on a CSP production line. It was discovered that arsenic segregated on grain boundaries when the steel was annealed at 950℃ for 2 h. When the annealing temperature increased to 1100℃, arsenic was also found to have segregated on grain boundaries in the early annealing stage, for instance, within the first 5 min annealing time. However, if the holding time of the steel at this temperature increased to 2 h, arsenic diffused away from grain boundaries into the matrix again. Nitrogen was not found to have segregated on grain boundaries when the steel was annealed at a relatively low temperature, such as 950℃. But when the annealing temperature increased to 1100℃, nitrogen was detected to have segregated at grain boundaries in the steel.

关键词： alloy steel arsenic nitrogen segregation grain boundaries

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Free Boundary Problems with Local-nonlocal Diffusions and Different Free Boundaries Ⅰ: Global Solution

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Acta Mathematica Sinica,English Series 2022年第12期38卷 2265-2284页

作者： Xiu DONG jian ping WANG Ming Xin WANG School of Mathematics Harbin Institute of TechnologyHarbin 150001P.R.China School of Applied Mathematics Xiamen University of TechnologyXiamen 361024P.R.China School of Mathematics and Information Science Henan Polytechnic UniversityJiaozuo 454000P.R.China

We investigate a class of ecological models with local-nonlocal diffusions and different free *** is PartⅠof a two-part series,in which the existence,uniqueness,regularity and estimates of global solution is *** spreading-vanishing dichotomy,criteria governing spreading and vanishing,long-time behavior of solution and the estimation of the spreading speed when spreading happens will be studied in the separate PartⅡ.

关键词： Local-nonlocal diffusions different free boundaries existence-uniqueness global solution

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Bearing capacity analysis using the method of characteristics

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Acta Mechanica Sinica 2013年第2期29卷 179-188页

作者： jian-ping Sun Zhi-Ye Zhao Yi-Pik Cheng School of Civil and Environmental Engineering Nanyang Technological University Department of Civil Environmental and Geomatic EngineeringUniversity College London

Using the method of characteristics,the bearing capacity for a strip footing is *** method of characteristics leads to an exact true limit load when the calculations of the three terms in the bearing capacity formula are consistent with one collapse mechanism and the soil satisfies the associated flow *** the same time,the method of characteristics avoids the assumption of arbitrary slip surfaces,and produces zones within which equilibrium and plastic yield are simultaneously satisfied for given boundary *** exact solution without superposition approximation can still be expressed by Terzaghi＇s equation of bearing capacity,in which the bearing capacity factor N γλ is dependent on the dimensionless parameter λ and the friction angle φ.The influence of groundwater on the bearing capacity of the shallow strip footing is considered,which indicates that when the groundwater effect is taken into account,the error induced by the superposition approximation can be reduced as compared with dry soil *** results are presented in the form of charts which give the modified value（Nwγλc /Nγλc） of bearing capacity ***,an approximated analytical expression,which provides results in close agreement with those obtained by numerical analysis in this paper,has been suggested for practical application purposes.

关键词： Bearing capacity·The method of characteristics·Groundwater·Strip footing

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EAF steelmaking process with increasing hot metal charging ratio and improving slagging regime

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International Journal of Minerals,Metallurgy and Materials 2009年第4期16卷 375-382页

作者： jian-ping Duan Yong-liang Zhang Xue-min Yang Technical Center of Shanxi Taigang Stainless Corporation Limited Taiyuan Shanxi 030003 China Institute of Process Engineering Chinese Academy of Sciences Beijing 100190 China

A new electric arc furnace （EAF） steelmaking process with increasing hot metal charging ratio and improving slagging regime simultaneously was developed and applied in a 50 t electric arc furnace for more than a year at No. 1 Steelmaking Plant of Shanxi Taigang Stainless Corporation Limited. The essential fact of the new EAF steelmaking process was to charge hot metal in two portions or steps： firstly, 35wt%-40wt% hot metal was pretreated by blowing oxygen in a specially designed reactor for decar burization and improving hot metal temperature and melting premelted slag; secondly, 30wt% hot metal was charged into EAF with high basicity refining slags from ladle furnace （LF）-vacuum degassing furnace （VD） refining process. The results show that the hot metal charging ratio can reach to about 65wt%-70wt% for the new EAF steelrnaking process; meanwhile, the tap-to-tap time of a 50 t EAF can shorten by 5-10 min, the electricity consumption can decrease by 35-50 kW·h/t, the lime consumption can reduce by 10.5 kg/t of molten steel, and the content of harmful heavy metals in molten steel can be easily controlled to less than the upper limits of aimed steel specification or grade compared with the traditional EAF steelmaking process. In addition, the dephosphorization ability shows a slight strengthening, however, a small degree of lessening for desulphurization ability is observed for the new EAF steelmaking process, but the weakness of desulphurization ability cannot become an obstacle to its further application since a stronger desulphurization ability can be achieved during secondary refining of LF coupled with VD after EAF steelmaking process.

关键词： electric arc furnace (EAF) charge ratio slagging refining slags lime

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Asymmetric Synthesis and Crystal Structure of a Bioactive Morpholine Derivative

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Chinese Journal of Structural Chemistry 2007年第5期26卷 515-518页

作者： WANG jian-ping FU Yong-Ju WANG jian-Ge QIN jian-Hua CHEN Qing-Hua Department of Chemistry Luoyang Normal University Luoyang 471022China Chemical Engineering ＆ Pharmaceutics College Henan Universityof Science and Technology Luoyang 471003 China

A novel morpholine derivative was synthesized by Michael addition/internal nucleophilic substitution of 4-（L）-menthyloxy（1R,2S,5R）-butenolide with phenyl-glyalcohol under mild condition, and its structure was determined by X-ray diffraction. The target compound belongs to orthorhombic, space group P212121 with a = 5.7729（7）, b = 11.5032（14）, c = 25.161（3）A, Mr = 319.35, Z = 4, V = 1670.8（4）A^3, Dc = 1.270 g/cm3, μ（MoKα） = 0.094 mm^-1, F（000） = 680, Flack = 0.01（2）, R = 0.0398 and wR = 0.0914.

关键词： morpholine derivative α-phenyl-glyalcohol,4-(L)-menthyloxy-butenolide asymmetric synthesis

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Blockchain in energy systems:values,opportunities,and limitations

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Frontiers in Energy 2022年第1期16卷 9-18页

作者： Sijie CHEN jian ping Zheng YAN Jinjin LI Zhen HUANG Key Laboratory of Control of Power Transmission and Conversion(Ministry of Education) Shanghai Jiao Tong UniversityShanghai 200240China Key Laboratory for Thin Film and Microfabrication(Ministry of Education) Department of Micro/Nano-electronicsShanghai Jiao Tong UniversityShanghai 200240China Key Laboratory for Power Machinery and Engineering(Ministry of Education) Shanghai Jiao Tong UniversityShanghai 200240China

The structure of a power energy system is becoming more distributed than *** becomes challenging to manage such a system in a centralized way,because a central authority may not exist or may not be trusted by all *** is a promising tool to address this challenge,by enabling trusted collaboration in the absence of a trusted central *** use in the energy sector has been pioneered by several pilot ***,to date the energy sector has not seen large-scale deployment of blockchain,partly because the founders of those pilot projects,the public,and utilities have not reached consensus on the values and limitations of blockchain in *** perspective aims to bridge this ***,the philosophy and unique values of blockchain are ***,some promising blockchain-based applications in energy systems are ***,some common misunderstandings of blockchain in energy are ***,some frequently-asked questions from utilities are *** this perspective can help advance large-scale deployment of blockchain in energy systems.

关键词： blockchain immutability energy trading energy management data synchronization

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