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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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Polyphenols from Securidaca inappendiculata alleviated acute lung injury in rats by inhibiting oxidative stress sensitive pathways

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Chinese Herbal Medicines 2021年第3期13卷 381-388页

作者： Cong-lan ji Sheng Dai Hong Liu ji-yang dong Chun-sheng Liu jian Zuo Department of Pharmacy Anhui College of Traditional Chinese MedicineWuhu 241000China Department of Electronic Science Xiamen UniversityXiamen 361005China Yijishan Hospital Wannan Medical CollegeWuhu 241000China Key Laboratory of Non-coding RNA Transformation Research of Anhui Higher Education Institution(Wannan Medical College) Wuhu 241000China Provincial Engineering Laboratory for Screening and Re-evaluation of Active Compounds of Herbal Medicines in Southern Anhui(Wannan Medical College) Wuhu 241000China

Objective:Securidaca inappendiculata is a medicinal plant frequently used in the treatment of inflammatory diseases in south China.In this study,we aimed to explore its bioactive constituent which contributes to the anti-inflammatory activity.Methods:Polyphenol-enriched and polyphenol-deprived fractions(PRF and PDF,respectively)were separated from the ethanolic extract by HPD300 macroporous resin-based method,and their antiinflammatory activities were investigated on a lipopolysaccharide(LPS)-induced acute lung injury(ALI)model in rats.The possible mechanism of action in alleviating acute inflammation was studied using RAW264.7 cells.Results:Both Folin-Ciocalteu and^(1)H nuclear magnetic resonance(NMR)analyses showed that polyphenolic content in PRF was approximately 10 times higher than that of PDF,and this observation reflected in their antioxidative capacities.PRF but not PDF significantly decreased the level of malondialdehyde,suppressed the expression of nicotinamide phosphoribosyltransferase(NAMPT)protein,and improved the severity of ALI in rats.PRF at 10μg/mL effectively downregulated the expression of proteins NAMPT,HMGB1,TLR4,and p-p65,and scavenged the intracellular reactive oxygen species(ROS)in LPS-primed RAW264.7 cells.N-acetyl-L-cysteine exhibited similar inhibitory effects on ROS production and NAMPT-mediated TLR4/NF-κB activation in vitro,whereas nicotinamide mononucleotide antagonized all the changes induced by PRF during cotreatments.Conclusion:As an antioxidant,PRF exhibited potent anti-inflammatory activity under both in vivo and in vitro conditions by downregulating NAMPT and TLR4/NF-κB.Accordingly,polyphenols were identified as important bioactive constituents in S.inappendiculata targeting oxidative stress-sensitive proinflammatory pathways.

关键词： antioxidant polyphenols reactive oxygen species(ROS) Securidaca inappendiculata Hassk TLR4/NF-κB

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中学化学知识不确定性的教育价值及其实现

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教学与管理 2024年第4期 47-50页

作者：杨季冬周小翔王彦丹湖南师范大学化学化工学院长沙410081

知识往往具有不确定的属性,而中学化学教学中往往剔除了化学知识的不确定性,仅强调其确定性。若是能在中学化学教学中回归知识不确定性属性,则有助于未来科学的繁荣,为教师提供教学空间,激发学生的探究欲望,促进师生协同发展,从而突破... 详细信息

知识往往具有不确定的属性,而中学化学教学中往往剔除了化学知识的不确定性,仅强调其确定性。若是能在中学化学教学中回归知识不确定性属性,则有助于未来科学的繁荣,为教师提供教学空间,激发学生的探究欲望,促进师生协同发展,从而突破中学化学知识确定性教学的局限性。为了实现中学化学知识不确定性的教育价值,可以在课堂上正视知识的不完备,明确知识成立的条件,注重化学教学的思维发散,促使评价方式的多样性。

关键词：化学教学知识不确定性中学化学知识

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化学必备品格的内涵及构成要素——基于“学习强国”对化学家报道的分析

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化学教育（中英文） 2024年第9期45卷 66-71页

作者：杨季冬彭晓霞王后雄湖南师范大学化学化工学院湖南长沙410081 华中师范大学教师教育学院湖北武汉430079

基于扎根理论对“学习强国”平台中化学家的报道进行了质性分析,提炼、归纳化学家身上所具有的品格,从而构建了化学必备品格要素的结构体系。该体系以化学学科领域特有的品格、科学领域普遍具有的品格、各个领域普遍具有的品格等3大维... 详细信息

基于扎根理论对“学习强国”平台中化学家的报道进行了质性分析,提炼、归纳化学家身上所具有的品格,从而构建了化学必备品格要素的结构体系。该体系以化学学科领域特有的品格、科学领域普遍具有的品格、各个领域普遍具有的品格等3大维度为框架,包括热爱化学、绿色化学意识、批判质疑、严谨求真、求索创新等11个品格要素,这为理解化学必备品格提供了参考。

关键词：化学必备品格核心素养品格教育

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A fast space-time-domain Gaussian beam migration approach using the dominant frequency approximation

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Petroleum Science 2022年第4期19卷 1555-1565页

作者： dong-Lin Zhang jian-Ping Huang ji-dong yang Zhen-Chun Li Su-Bin Zhuang Qing-yang Li School of Geosciences China University of Petroleum(East China)QingdaoShandong 266580China Pilot National Laboratory for Marine Science and Technology QingdaoShandong 266580China Geophysical Exploration Research Institute of Zhongyuan Oilfield Company PuyangHenan 457001China

The Gaussian beam migration(GBM) is a steady imaging approach, which has high accuracy and efficiency. Its implementation mainly includes the traditional frequency domain and the recent popular space-time domain. Firstly, we use the upward ray tracing strategy to get the backward wavefields. Then,we use the dominant frequency of the seismic data to simplify the imaginary traveltime calculation of the wavefields, which can cut down the Fourier transform number compared with the traditional GBM in the space-time domain. In addition, we choose an optimized parameter for the take-off angle increment of the up-going and down-going rays. These optimizations help us get an efficient space-time-domain acoustic GBM approach. Typical four examples show that the proposed method can significantly improve the computational efficiency up to one or even two orders of magnitude in different models with different model parameters and produce good imaging results with comparable accuracy and resolution with the traditional GBM in the space-time domain.

关键词： Gaussian beam Space-time-domain Fast Dominant frequency approximation

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A computational method for wide-azimuth 3D dip-angle gathers using Gaussian beam migration

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Petroleum Science 2022年第5期19卷 2081-2094页

作者： Su-Bin Zhuang jian-Ping Huang ji-dong yang Zhen-Chun Li School of Geosciences China University of Petroleum(East China)Qingdao266580ShandongChina

The dip-angle-domain common-image gather(DDCIG)is a key tool to separate the diffraction and reflection imaging results.Reflectors with different spatial geometries produce different responses in DDCIGs.Compared with Kirchhoff migration,Gaussian beam migration(GBM)is more effective and robust to overcome the multipathing problem.As a ray-based method,it has explicit angle information naturally during the propagation.We have developed a 3D DDCIG computational method using GBM,which obtain both the imaging result and angle-domain gathers with only one pass of calculation.The angle-gather computation is based on geometrical optics,and multiple angle conversions are implemented under the rules of space geometry,which helps to avoid rounding errors and improve accuracy.Additionally,the multi-azimuth joint presentation strategy is proposed to describe the characteristic of omnidirectional dip angles using a finite number of gathers.After using a 2D model to illustrate application advantages of DDCIG,we apply the proposed method to two 3D models to test its feasibility and accuracy.A field data example further demonstrates the adaptability of our method to seismic imaging for a land survey.

关键词： Gaussian beam Dip-angle gathers 3D imaging Diffraction

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2D Q-compensated multi-component elastic Gaussian beam migration

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Petroleum Science 2023年第1期20卷 230-240页

作者： Chao Chen ji-dong yang Xin-Ru Mu Zhen-Chun Li jian-Ping Huang China University of Petroleum(East China) Qingdao266580ShandongChina

Elastic waves are affected by viscoelasticity during the propagation through the Earth,resulting in energy attenuation and phase distortion,in turn resulting in low seismic imaging accuracy.Therefore,viscoelasticity should be considered in seismic migration imaging.We propose a Q compensated multicomponent elastic Gaussian beam migration(Q-EGBM)method to(1)separate the elastic-wave data into longitudinal(P)and transverse(S)waves to perform PP-wave and PS-wave imaging;(2)recover the amplitude loss caused by attenuation;(3)correct phase distortions caused by dispersion;(4)improve the resolution of migration imaging.In this paper,to accomplish(2),(3),and(4),we derive complex-valued traveltimes in viscoelastic media.The results of numerical experiments using a simple five-layer model and a sophisticated BP gas model show that the method presented here has significant advantages in recovering energy decay and correcting phase distortion,as well as significantly improving imaging resolution.

关键词： Q-compensated Viscoelastic Gaussian beam migration Multi-component Absorption attenuation

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Extracting angle-domain common-image gathers in VTI media using ansiotropic-Helmholtz P/S wave-mode decomposition

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Petroleum Science 2023年第3期20卷 1546-1561页

作者： Le-Le Zhang yang Zhao Lu Liu Ke Chen jia-Hui Zuo Yi-Xin Wang ji-dong yang State Key Laboratory of Petroleum Resource and Prospecting Unconventional Petroleum Research InstituteChina University of PetroleumBeijing102249China Aramco Beijing Research Center Aramco AsiaBejing100102China Department of Geophysics China University of Petroleum(East China)QingdaoShandong266580China

Common-image gathers are extensively used in amplitude versus angle(AVA)and migration velocity analysis(MVA).The current state of methods for anisotropic angle gathers extraction use slant-stack,local Fourier transform or low-rank approximation,which requires much computation.Based on an anisotropic-Helmholtz P/S wave-mode decomposition method,we propose a novel and efficient approach to produce angle-domain common-image gathers(ADCIGs)in the elastic reverse time migration(ERTM)of VTI media.To start with,we derive an anisotropic-Helmholtz decomposition operator from the Christoffel equation in VTI media,and use this operator to derive the decomposed formulations for anisotropic P/S waves.Second,we employ the first-order Taylor expansion to calculate the normalized term of decomposed formulations and obtain the anisotropic-Helmholtz decomposition method,which generates the separated P/S wavefields with correct amplitudes and phases.Third,we develop a novel way that uses the anisotropic-Helmholtz decomposition operator to define the polari-zation angles for anisotropic P/S waves and substitute these angles to decomposing formulations.The polarization angles are then calculated directly from the separated vector P-and S-wavefields and converted to the phase angles.The ADCIGs are thusly produced by applying the phase angles to VTI ERTM.In addition,we develop a concise approximate expression of residual moveout(RMO)for PP-reflections of flat reflectors in VTI media,which avoids the complex transformations between the group angles and the phase angles.The approximate RMO curves show a good agreement with the exact solution and can be used as a tool to assess the migration velocity errors.As demonstrated by two selected examples,our ADCIGs not only produce the correct kinematic responses with regards to different velocity pertubatation,but also generate the reliable amplitude responses versus different angle.The final stacking images of ADCIGs data exhibit the identical imaging effect as that of VTI ERTM.

关键词： Helmholtz decomposition Angle gathers Anisotropy Elastic-RTM

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Experimental and numerical investigation of the impacts of rotor tip-rake on excitation forces of pump-jet propulsors

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Journal of Hydrodynamics 2024年第1期36卷 142-157页

作者： Xue-qin ji Xiao-song Zhang Chen-jun yang Xiao-qian dong State Key Laboratory of Ocean Engineering Marine Numerical Experiment CentreSchool of Naval ArchitectureOcean and Civil EngineeringShanghai Jiao Tong UniversityShanghai200240China CSSC Shanghai Marine Energy Saving Technology Co. Ltd.Shanghai200011China China Ship Scientific Research Center Shanghai Branch Shanghai200011China

The tip-clearance flow in a pump-jet propulsor exerts great impacts on the fluctuating pressures and resultant unsteady forces,which are important sources of structural vibrations and radiated noise underwater.The blade geometry close to the tip is an important factor determining the vortex strength in the tip-clearance flow.In the open-water condition,the effects of raking the rotor tips on the duct-surface fluctuating pressures and the resultant unsteady forces acting on different components of the propulsor are investigated via physical model experiments and the numerical solution of Reynolds-averaged Navier-Stokes(RANS)equations coupled with the SST k-ωturbulence model.The measured and simulated results of hydrodynamic pressures are consistent to each other,and the simulated flows help better understand why the fluctuating pressures change with the tip geometry.The strong fluctuations of duct-surface pressures are caused by intensive tip separation vortices.The duct-surface pressure fluctuations are effectively reduced by using the rake distribution near the tip towards blade back side and,for the combination of the five-bladed rotor and the seven-bladed stator,the resultant unsteady horizontal(and vertical)forces acting on the duct and stator are also reduced;while increasing rake leads to negative effect on pressure fluctuations and unsteady horizontal(and vertical)forces acting on all the components of the propulsor.

关键词： Pump-jet tip-clearance tip-rake fluctuating pressures excitation forces

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Silicone oil as a corneal lubricant to reduce corneal edema and improve visualization during

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International Journal of Ophthalmology(English edition) 2024年第1期17卷 92-96页

作者： Dan-yang Che Zhu-Lin Chan ji-Bo Zhou dong-Qing Zhu Department of Ophthalmology Ninth People’s HospitalShanghai Jiao Tong University School of MedicineShanghai 200011China College of Health Science and Technology Shanghai Jiao Tong University School of MedicineShanghai 200011China The PLA Navy Anqing Hospital Anqing 246004Anhui ProvinceChina

AIM:To evaluate the efficacy and safety of silicone oil(SO)as a corneal lubricant to improve visualization during vitrectomy.METHODS:Patients who underwent vitreoretinal surgery were divided into two groups.Group 1 was operated on with initial SO(Oxane 5700)as a corneal lubricant.Group 2 was operated on with initial lactated ringer’s solution(LRS)and then replaced with SO as required.Fundus clarity was scored during the surgery.Fluorescein staining was performed to determine the damage to corneal epithelium.RESULTS:Totally 114 eyes of 114 patients were included.Single SO use maintained a clear cornea and provided excellent visualization of surgical image.In group 1,the fundus clarity was grade 3 in 41/45 eyes and grade 2 in 4/45 eyes.In group 2,corneal edema frequently occurred after initial LRS use.The fundus clarity was grade 3 in 19/69 eyes,2 in 37/69 eyes and 1 in 13/69 eyes(P0.05).CONCLUSION:The use of SO as a corneal lubricant is effective and safe for preserving and improving corneal clarity and providing clear surgical field during vitrectomy.

关键词： silicone oil corneal lubricant corneal edema vitrectomy

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