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Theoretical analysis and numerical simulation of acoustic waves in gas hydrate-bearing sediments

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Chinese Physics B 2021年第2期30卷 344-354页

作者： Lin Liu xiu-mei zhang xiu-Ming Wang State Key Laboratory of Acoustics Institute of AcousticsChinese Academy of SciencesBeijing 100190China University of Chinese Academy of Sciences Beijing 100149China Beijing Engineering Research Center of Sea Deep Drilling and Exploration Institute of AcousticsChinese Academy of SciencesBeijing 100190China

Based on Carcione-Leclaire model,the time-splitting high-order staggered-grid finite-difference algorithm is proposed and constructed for understanding wave propagation mechanisms in gas hydrate-bearing *** compressional waves and two shear waves,as well as their energy distributions are investigated in *** particular,the influences of the friction coefficient between solid grains and gas hydrate and the viscosity of pore fluid on wave propagation are *** results show that our proposed numerical simulation algorithm proposed in this paper can effectively solve the problem of stiffness in the velocity-stress equations and suppress the grid dispersion,resulting in higher accuracy compared with the result of the Fourier pseudospectral method used by *** excitation mechanisms of the five wave modes are clearly revealed by the results of ***,it is pointed that,the wave diffusion of the second kind of compressional and shear waves is influenced by the friction coefficient between solid grains and gas hydrate,while the diffusion of the third compressional wave is controlled by the fluid ***,two fluid-solid(gas-hydrate formation)models are constructed to study the mode conversion of various *** results show that the reflection,transmission,and transformation of various waves occur on the interface,forming a very complicated wave field,and the energy distribution of various converted waves in different phases is *** is demonstrated from our studies that,the unconventional waves,such as the second and third kinds of compressional waves may be converted into conventional waves on an *** propagation mechanisms provide a concrete wave attenuation explanation in inhomogeneous media.

关键词： gas hydrate-bearing sediments Carcione-Leclaire model time-splitting staggered-grid finite-difference slow-wave characteristics

Generalized collar waves in acoustic logging while drilling

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Chinese Physics B 2016年第12期25卷 118-120页

作者：王秀明何晓张秀梅 State Key Laboratory of Acoustics Institute of AcousticsChinese Academy of Sciences

Tool waves, also named collar waves, propagating along the drill collars in acoustic logging while drilling （ALWD）, strongly interfere with the needed P- and S-waves of a penetrated formation, which is a key issue in picking up formation P- and S-wave velocities. Previous studies on physical insulation for the collar waves designed on the collar between the source and the receiver sections did not bring to a satisfactory solution. In this paper, we investigate the propagation features of collar waves in different models. It is confirmed that there exists an indirect collar wave in the synthetic full waves due to the coupling between the drill collar and the borehole, even there is a perfect isolator between the source and the receiver. The direct collar waves propagating all along the tool and the indirect ones produced by echoes from the borehole wall are summarized as the generalized collar waves. Further analyses show that the indirect collar waves could be relatively strong in the full wave data. This is why the collar waves cannot be eliminated with satisfactory effect in many cases by designing the physical isolators carved on the tool.

关键词： acoustic logging while drilling borehole wave propagation generalized collar waves indirectcollar waves

Optimizing surgical outcomes for elderly gallstone patients with a high body mass index using enhanced recovery after surgery protocol

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World Journal of Gastrointestinal Surgery 2023年第10期15卷 2191-2200页

作者： Yue-Xia Gu Xin-Yu Wang Yang Chen Jun-xiu Shao Shen-Xian Ni xiu-mei zhang Si-Yu Shao Yu zhang Wen-Jing Hu Ying-Ying Ma Meng-Yao Liu Hua Yu Department of Nursing Shanghai Fourth People’s Hospital Affiliated to Tongji University School of MedicineShanghai 200434China Department of General Surgery Shanghai Fourth People’s Hospital School of Medicine Tongji UniversityShanghai 200434China Department of Nursing Shanghai Xuhui Central HospitalShanghai 200031China

BACKGROUND Rehabilitation of elderly patients with a high body mass index(BMI)after cholecystectomy carries risks and requires the adoption of effective perioperative management *** enhanced recovery after surgery(ERAS)protocol is a comprehensive treatment approach that facilitates early patient recovery and reduces postoperative *** To compare the effectiveness of traditional perioperative management methods with the ERAS protocol in elderly patients with gallbladder stones and a high *** This retrospective cohort study examined data from 198 elderly patients with a high BMI who underwent cholecystectomy at the Shanghai Fourth People's Hospital from August 2019 to August *** them,99 patients were managed using the traditional perioperative care approach(non-ERAS protocol),while the remaining 99 patients were managed using the ERAS *** indicator data were collected for patients preoperatively,intraoperatively,and postoperatively,and surgical outcomes were compared between the two *** The comparison results between the two groups of patients in terms of age,sex,BMI,underlying diseases,surgical type,and preoperative hospital stay showed no statistically significant ***,the ERAS group had a significantly shorter preoperative fasting time than the non-ERAS group(4.0±0.9 h vs 7.6±0.9 h).Regarding intraoperative indicators,there were no significant differences between the two groups of ***,in terms of postoperative recovery,the ERAS protocol group exhibited significant advantages over the non-ERAS group,including a shorter hospital stay,lower postoperative pain scores and postoperative hunger scores,and higher satisfaction *** readmission rate was lower in the ERAS protocol group than in the non-ERAS group(3.0%vs 8.1%),although the difference was not ***,there were significant differences between the two groups in terms of postoperative nausea and vomit

关键词： Enhanced recovery after surgery protocol Cholecystectomy Rehospitalization rate Postoperative nausea and vomiting Degree of abdominal distension Daily living ability

Reachable Set Estimation of a class of Human-in-the-Loop Control Systems

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Reachable Set Estimation of a class of Human-in-the-Loop Con...

第40届中国控制会议

作者： xiu-mei zhang Huai-Ning Wu Science and Technology on Aircraft Control Laboratory School of Automation Science and Electrical EngineeringBeihang University

This paper studies the reachable set estimation problem of a class of human-in-the-loop（Hi TL） control systems described by a controlled hidden Markov jump model. Our aim is to determine an ellipsoid-like set which bounds all the machine state trajectories of the Hi TL system under zero initial condition. By using a stochastic Lyapunov functional, a reachable set estimation condition is established, which is provided in terms of a set of matrix inequalities. Finally, an example is given to show the effectiveness of the proposed result.

关键词： Human-in-the-loop control system Markov jump system reachable set estimation stochastic Lyapunov functional

P26 Study Pharmacology to be a Good Physician

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中国药理通讯 2006年第2期23卷 31-32页

作者： Bin zhang Zi-ying Wang Hui-qing Liu xiu-mei zhang Institute of Pharmacology School of Medicine Shandong University 44 West Wenhua Road Jinan 250012 China

INTER-SOURCE PASSIVE BODY-WAVE INTERFEROMETRY BY MULTIDIMENSIONAL DECONVOLUTION(MDD)

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INTER-SOURCE PASSIVE BODY-WAVE INTERFEROMETRY BY MULTIDIMENS...

2016年全国压电和声波理论及器件应用研讨会

作者： Li-wen XU Hao CHEN xiu-mei zhang State Key Laboratory of Acoustics Institute of AcousticsChinese Academy of Sciences

Background, Motivation and Objective Analogous to optical interferometry, scientists have developed seismic interferometry(SI) method, and its application in the field data have promoted the understanding and study of seismic wave propagation. Seismic interferometry can be applied to both controlled-source data and passive data. Under specific circumstances, the useful subsurface information can be retrieved with passive noise source seismic interferometry. In recent years, researchers have successfully retrieved body waves by cross-correlating wave fields observed at two receivers. The retrieved wave fields are mostly between pairs of receivers in the surface. When the new wave fields are retrieved between two receiver positions, it is called inter-receiver SI, and the inter-source SI is the wave fields retrieved between two source positions. The principle is known as seismic interferometry or Green’s function retrieval. An alternative to the cross correlation(CC) is the multidimensional deconvolution(MDD), which has the potential to suppress artifacts due to source irregularity. Statement of Contribution/Methods Using source-receiver reciprocity, we can retrieve the Green’s function between pairs of sources positions. With a numerical example, we show that the retrieved wave fields by inter-source MDD is more adequate than that by CC. To suppress the artifacts, we separate the wave fields recording at receivers into inward and outward wave fields to improve the quality of imaging. In a simple model, the inward and outward wave fields reduce to primary reflected waves and direct waves. In this letter, we use the method for passive seismic interferometry by inter-source MDD and established two kinds of model, one is the sources are aligned at a given depth and the other one is the irregular source distribution. We compare the results of both CC and inter-source MDD, and analyzed to further demonstrate the effectiveness of the inter-source MDD method. Results The res

关键词： Seismic interferometry Multidimensional deconvolution Inversion Body wave

ANALYSIS OF RADIAL DETECTION CHARACTERISTICS OF MONOPOLE SONIC LOGGING

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ANALYSIS OF RADIAL DETECTION CHARACTERISTICS OF MONOPOLE SON...

2016年全国压电和声波理论及器件应用研讨会

作者： Yi-han GENG Hao CHEN Xiao HE xiu-mei zhang xiu-ming WANG University of Chinese Academy of Sciences State Key laboratory of Acoustics Institute of Acoustics Chinese Academy of Sciences

ISBN: (纸本)9781509011902

Background, Motivation and Objective Drilling causes variation of the rock properties in the vicinity of a wellbore. Usually, acoustic velocities, including P-and S-wave ones near the borehole wall are smaller than those of the virgin formation. In order to understand the velocity profile along the borehole radial direction for formation characterizations, we investigate the influence of the thickness of the transition zone on monopole longitudinal waves at varying source-to-receiver separations and frequency range based on the radial stepped sonic model. This research may be applied for radial tomography of longitudinal wave velocity with monopole logging tools. Statement of Contribution/Methods In this article, we use the radial cylindrical layered model to examine monopole logging response with a two-dimensional axisymmetric finite difference method. Three variables are set, and they are the transition zone thickness, the source frequency and source-to-receiver spacing, respectively. We also use the slowness-time correlation-method to evaluate sound speed variations under different conditions. At last, based on the ray theory, the variation characteristics of the arrival time of the first wave under different conditions are analyzed. Results For a certain source-to-receiver offset, there is a critical value for the intermediate layer thickness. When the intermediate layer thickness is less than that value, the first wave is the outermost layer formation compressional wave. When the intermediate layer thickness is greater than that value, the first wave is the compressional wave of the formation closest to the wellbore. The longitudinal waves sliding along different interfaces can be separated from each other in the time domain with the appropriate source to receiver offset. According to this result, one can possibly obtain different speeds of the intermediate layers. Meanwhile, the first wave amplitude is gradually weakened as the spacing increases. For sources w

关键词： Acoustic logging Radial detection depth Finite difference method Slowness-time correlation-method

A New 3D Co（Ⅱ） Coordination Polymer with Mixed Azide-Tetrazolate Showing Slow MagneticRelaxation

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A New 3D Co（Ⅱ） Coordination Polymer with Mixed Azide-Tetr...

中国化学会第八届全国配位化学会议

作者： Wei Gao Jie-Ping Liu xiu-mei zhang Qing-Yu Gao College of Chemical Engineering ChinaUniversity of Mining and Technology College of Chemistry and Materials Science Huaibei Normal University

Tetrazolate and azide ions can act as short bridges to construct molecular magnetism because they can bind two or more metal ions in various modes and can mediate ferromagnetic（FM） or antiferromagnetic（AFM） coupling. In this work, a novel 3 D Co（Ⅱ） coordination polymer was synthesized by in situ hydrothermal. X-ray analyses revealed that this compound exhibits a 3 D network structures based on azide-tetrazolate-bridged 1 D chains. The magnetic studies show that the compound exhibits the spin-glass slow dynamics.

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Microstructural evolution during the progressive transformation-induced plasticity effect in a Fe-0.1C-5Mnmedium manganese steel

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International Journal of Minerals,Metallurgy and Materials 2025年第2期32卷 369-379页

作者： mei zhang Wenhao Li Yangfei Chen Yang Jiang Xiaofei Guo Han Dong School of Materials Science and Engineering Shanghai UniversityShanghai 200444China State Key Laboratory of Advanced Special Steel Shanghai UniversityShanghai 200444China

The microstructural evolution of a cold-rolled and intercritical annealed medium-Mn steel(Fe-0.10C-5Mn)was investigated during uniaxial tensile ***-situ observations under scanning electron microscopy,transmission electron microscopy,and X-ray diffraction analysis were conducted to characterize the progressive transformation-induced plasticity process and associated fracture initiation *** findings were discussed with the local strain measurements via digital image *** results indicated that Lüders band formation in the steel was limited to 1.5%strain,which was mainly due to the early-stage martensitic phase transformation of a very small amount of the less stable large-sized retained austenite(RA),which led to localized stress concentrations and strain hardening and further retardation of *** small-sized RA exhibited high stability and progressively transformed into martensite and contributed to a stably extended Portevin-Le Chatelier *** volume fraction of RA gradually decreased from 26.8%to 8.2%prior to *** the late deformation stage,fracture initiation primarily occurred at the austenite/martensite and ferrite/martensite interfaces and the ferrite phase.

关键词： medium-Mn steel retained austenite progressive transformation-induced plasticity effect local strain fracture initiation