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Elastic properties of transversely isotropic rocks containing aligned cracks and application to anisotropy measurement

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Applied Geophysics 2020年第2期17卷 182-191,314页

作者： Xu Song Su Yuan-Dat Tang Xiao-Ming key laboratory of deep Oil and Gas China University of petroleumQingdao 266580China School of Geosciences China University of PetroleumQingdao 266580China China laboratory for Marine Mineral resources Qingdao National Laboratory for Marine Science and TechnologyQingdao 266071China

Currently,most rock physics models,used for evaluating the elastic properties of cracked or fractured media,take into account the crack properties,but not the background *** creats the errors of in the anisotropy estimates by using fi eld logging *** this work,based on the scattered wavefi eld theory,a sphere-equivalency method of elastic wave scattering was developed to accurately calculate the elastic properties of a vertical transversely isotropic solid containing aligned *** setting the scattered wavefi eld due to a crack equal to that due to an equivalent sphere,an eff ective elastic stiff ness tensor was derived for the cracked *** stability and accuracy of the approach were determined for varying background anisotropy *** results show that the anisotropy of the eff ective media is aff ected by cracks and background anisotropy for transversely isotropic background permeated by horizontally aligned cracks,especially for the elastic wave propagating along the horizontal ***,the crack orientation has a signifi cant infl uence on the elastic wave velocity *** theory was subsequently applied to model laboratory ultrasonic experimental data for artifi cially cracked samples and to model borehole acoustic anisotropy *** considering the background anisotropy,the model shows an improvement in the agreement between theoretical predictions and measurement data,demonstrating that the present theory can adequately explain the anisotropic characteristics of cracked media.

关键词： anisotropy aligned cracks alignment direction elastic wave velocity data processing

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Wet flue gas desulfurization performance of 330 MW coal-fired power unit based on computational fluid dynamics region identification of flow pattern and transfer process

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Chinese Journal of Chemical Engineering 2021年第1期34卷 13-26页

作者： Jiangyuan Qu Nana Qi Kai Zhang Lifeng Li PengchengWang Beijing key laboratory of Emission Surveillance and Control for Thermal Power Generation North China Electric Power UniversityBeijing 102206China key laboratory of Power Station Energy Transfer Conversion and System(North China Electric Power University) Ministry of EducationBeijing 102206China Shanxi Hepo Power Generation Company Limited Yangquan 045011China

Wet Flue Gas Desulfurization(WFGD)unit based upon spray scrubber has beenwidely employed to control SO_(2) emissions from flue gas in coal-fired power *** clarify the dependence of desulfurization performance on inter-phase transfer behaviors with non-ideal contacting patterns of flue gas and slurry droplets,three regions in spray scrubber are distinguished in terms of gas-slurry flow structures using CFD method in the Eulerian-Lagrangian framework.A comprehensive model is established by involving the transfer process between two phases and chemical reactions in aqueous phase,which is validatedwith the measured data froma WFGD scrubber of 330 MW coal-fired power *** results show that the overall uniformity degree of flue gas in whole scrubber is largely determined by the force-balanced droplets in the middle part of scrubber,which is dominated by counter-current *** momentum transfer behavior and SO_(2) chemical absorption process present the synchronicity with the evolution of gas-slurry flow pattern,whilst the heat transfer together with H_(2)O evaporation has little effect on overall absorption *** regions are firstly defined as Gas Inlet Region(GIR),Dominant Absorption Region(DAR)and Slurry Dispersed Region(SDR)from the bottom to top of ***_(2) is mainly scrubbed in DAR,which provides much more intensive interaction between two phases compared to GIR or SDR.A better understanding of the desulfurization process is obtained from the fundamental relationship between transport phenomena and chemical reactions based upon the complicated hydrodynamics of gas-slurry two-phase flow,which should be useful for designing and optimizing the scrubber in coal-fired power unit.

关键词： Wet flue gas desulfurization Gas-liquid flow Eulerian-Lagrangian model Flow pattern Transport processes Absorption

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Significance of the normalized seasonality of wind field and its rationality for characterizing the monsoon

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Science China earth Sciences 2000年第6期43卷 646-653页

作者：李建平曾庆存 State key laboratory of Numerical Modelling for Atmospheric Sciences and Geophysical Fluid dynamics (LASG) Institute of Atmospheric Physics Chinese Academy of Sciences Beijing 100029 China Correspondence should be addressed to Li Jianping

The significance of the normalized seasonality of wind field is theoretically studied and the intrinsic relationship between its critical value and the definition of the monsoon region is revealed. As a result, the rationality which the monsoon region is characterized by the significant normalized seasonality is proved. Based on this, by use of the NECP/NCAR reanalysis data during 1958-1997, the spatial structure of the significant normalized seasonality of wind field is investigated, and the significant baroclinity of the seasonal variation of the atmospheric general circulation in the vertical direction is verified. Moreover, in the tropics there exists an anti-symmetric distribution between the significant seasonality in the eastern hemisphere and that in the western hemisphere, and the monsoon is linked closely to some important systems such as the subtropical highs, the night jet and the west wind channels.

关键词： normalized seasonality monsoon monsoon region significance baroclinity western hemisphere tropical monsoon.

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Reversed configuration of photocatalyst to exhibit improved properties of basic processes compared to conventional one

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Science China Chemistry 2020年第6期63卷 771-776页

作者： Juhong Lian Yu Qi Yunfeng Bao Zixi Yin Yang Zhang Nengcong Yang Naijia Guan Shengye Jin Landong Li Fuxiang Zhang State key laboratory of Catalysis iChEMDalian Institute of Chemical PhysicsChinese Academy of SciencesDalian National Laboratory for Clean EnergyDalian 116023China School of Materials Science and Engineering National Institute for Advanced MaterialsNankai UniversityTianjin 300350China State key laboratory of Molecular Reaction dynamics and Collaborative Innovation Center of Chemistry for Energy Materials(iChEM) Dalian Institute of Chemical PhysicsChinese Academy of SciencesDalian 116023China

Performances of semiconductor photocatalysts are integrally determined by efficiencies of basic processes such as light absorption,charge separation and surface catalysis,but conventional configurations of photocatalysts normally suffers from the competition of light absorption originating from cocatalyst deposition and limited interface charge separation between the photocatalyst and *** we give the first proof-of-concept illustration that a reversed configuration of photocatalysts with a core/shell structure of microsized Mo2N cocatalysts and nanosized CdS photocatalysts,which exhibits superior solar hydrogen production to the conventional configuration with nanosized Mo2N cocatalysts deposited on the surface of CdS *** is revealed that the reversed configuration outperforms the conventional one in all areas of light absorption,charge separation and surface ***,the special core/shell structure introduced here can well avoid the competition of light absorption by cocatalysts and make an effective confinement effect to promote the surface catalysis of *** finding provides an alternative strategy to improve performances of photocatalysts.

关键词： photocatalyst nitride semiconductor renewable hydrogen core/shell

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Rapid identification of time-frequency domain gravitational wave signals from binary black holes using deep learning

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Chinese Physics C 2024年第12期48卷 230-242页

作者： Yu-Xin Wang Shang-Jie Jin Tian-Yang Sun Jing-Fei Zhang Xin Zhang key laboratory of Cosmology and Astrophysics(Liaoning)&College of Sciences Northeastern UniversityShenyang 110819China key laboratory of Data Analytics and Optimization for Smart Industry(ministry of Education) Northeastern UniversityShenyang 110819China National Frontiers Science Center for Industrial Intelligence and Systems Optimization Northeastern UniversityShenyang 110819China

Recent developments in deep learning techniques have provided alternative and complementary approaches to the traditional matched-filtering methods for identifying gravitational wave(GW)*** rapid and accurate identification of GW signals is crucial to the advancement of GW physics and multi-messenger astronomy,particularly considering the upcoming fourth and fifth observing runs of *** this study,we used the 2D U-Net algorithm to identify time-frequency domain GW signals from stellar-mass binary black hole(BBH)*** simulated BBH mergers with component masses ranging from 7 to 50 M_(⊙)and accounted for the LIGO detector *** found that the GW events in the first and second observation runs could all be clearly and rapidly *** the third observing run,approximately 80% of the GW events could be *** contrast to traditional convolutional neural networks,the U-Net algorithm can output time-frequency domain signal images corresponding to probabilities,providing a more intuitive *** conclusion,the U-Net algorithm can rapidly identify the time-frequency domain GW signals from BBH mergers.

关键词： gravitational waves deep learning binary black holes time-frequency domain signals U-Net algorithm

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Experimental research on overlying strata movement and fracture evolution in pillarless stress-relief mining

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International Journal of Coal Science & Technology 2015年第1期2卷 38-45页

作者： Junhua Xue Hanpeng Wang Wei Zhou Bo Ren Changrui Duan Dongsheng Deng State key laboratory of deep Coal Mining & Environment Protection Huainan 232001 China Geotechnical & Structural Engineering Research Center Shandong University Jinan 250012 China

In multiple seams mining, the seam with relatively low gas content （protective seam） is often extracted prior to mining its overlying and/or underlying seams of high gas content and low permeability to minimize the risk of high gas emission and outbursts of coal and gas. A key to success with this mining sequence is to gain a detailed understanding of the movement and fracture evolution of the overlying and underlying strata after the protective seam in extracted. In Zhuji mine, the No. 11-2 seam is extracted as a protective seam with the pillarless mining method by retaining goal-side roadways prior to its overlying No. 13-1 seam. An investigation has been undertaken in the panel 1111 （1） of Zhuji mine to physically simulate the movement and fracture evolution of the overlying strata alter the No. 1 I-2 seam is extracted. In the physical simulation, the displacement, strain, and deformation and failure process of the model for simulation were acquired with various means such as grating displacement meter, strain gauges, and digital photography. The simulation result shows that：（1） Initial caving interval of the immediate roof was 21.6 m, the first weighting interval was 23.5-37.3 m with the average interval of 33.5 m, and the periodic weighting interval of the main roof was in a range of 8.2-20.55 m and averaged at 15.2 m. （2） The maximum height of the caving zone after the extraction of No. 11-2 seam was 8.0 m, which was 4 times of the seam mining height and the internal strata of the caving zone collapsed irregularly. The mining-induced fractures developed 8-30 m above the mined No. 11-2 seam, which was 7.525 times of the seam mining height, the fracture zone was about 65° upward from the seam open-off cut toward the goaf, the height of longitudinal joint growth was 4-20 times of the mining seam height, and the height of lateral joint growth was 20-25 times of the mining seam height. （3） The ＂arch-in-arch＂ mechanical structure of the internal goaf was bounded by

关键词： Low-permeability coal seam Pillarless stress-relief mining Overburden movement Fracture evolution Physical simulation

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Diffraction deep neural network-based classification for vector vortex beams

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Chinese Physics B 2024年第3期33卷 387-392页

作者：彭怡翔陈兵王乐赵生妹 Institute of Signal Processing and Transmission Nanjing University of Posts and Telecommunications (NJUPT)Nanjing 210003China key laboratory of Broadband Wireless Communication and Sensor Network Technology Ministry of EducationNanjing 210003China National laboratory of Solid State Microstructures Nanjing UniversityNanjing 210093China

The vector vortex beam(VVB)has attracted significant attention due to its intrinsic diversity of information and has found great applications in both classical and quantum ***,a VVB is unavoidably affected by atmospheric turbulence(AT)when it propagates through the free-space optical communication environment,which results in detection errors at the *** this paper,we propose a VVB classification scheme to detect VVBs with continuously changing polarization states under AT,where a diffractive deep neural network(DDNN)is designed and trained to classify the intensity distribution of the input distorted VVBs,and the horizontal direction of polarization of the input distorted beam is adopted as the feature for the classification through the *** numerical simulations and experimental results demonstrate that the proposed scheme has high accuracy in classification *** energy distribution percentage remains above 95%from weak to medium AT,and the classification accuracy can remain above 95%for various strengths of *** has a faster convergence and better accuracy than that based on a convolutional neural network.

关键词： vector vortex beam diffractive deep neural network classification atmospheric turbulence

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Contributions of shortwave radiation to the formation of temperature inversions in the Bay of Bengal and eastern equatorial Indian Ocean:A modeling approach

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Acta Oceanologica Sinica 2022年第9期41卷 19-37页

作者： K M Azam Chowdhury Wensheng Jiang Changwei Bian Guimei Liu Md Kawser Ahmed Shaila Akhter College of Oceanic and Atmospheric Sciences Ocean University of ChinaQingdao266100China Department of Oceanography&International Centre for Ocean Governance(ICOG) University of DhakaDhaka1000Bangladesh National Marine Environmental Forecasting Center Beijing100081China key Lab of Marine Environment and Ecology of ministry of Education Ocean University of ChinaQingdao266100China Frontiers Science Center for deep Ocean Multispheres and earth System(FDOMES) Ocean University of ChinaQingdao266100China Pilot National laboratory for Marine Science and Technology(Qingdao) Qingdao266237China Bangladesh Betar Ministry of Information and BroadcastingGovernment of the People’s Republic of BangladeshDhaka1207Bangladesh

Variations in incoming shortwave radiation influence the net surface heat flux,contributing to the formation of a temperature *** effects of shortwave radiation on the temperature inversions in the Bay of Bengal and eastern equatorial Indian Ocean have never been ***,a high-resolution(horizontal resolution of 0.07°×0.07° with 50 vertical layers) Regional Ocean Modeling System(ROMS) model is utilized to quantify the contributions of shortwave radiation to the temperature inversions in the study *** of the mixed layer heat and salt budgets are performed,and different model simulations are *** model results suggest that a 30% change in shortwave radiation can change approximately 3% of the temperature inversion area in the Bay of *** shortwave radiation reduces the net surface heat flux and cools the mixed layer substantially;it also reduces the evaporation rate,causing less evaporative water vapor losses from the ocean than the typical situation,and ultimately enhances haline ***,the rudimentary outcome of this research is that a decrease in shortwave radiation produces more temperature inversion in the study region,which is primarily driven by the net surface cooling and supported by the intensive haline ***,low shortwave radiation eventually intensifies the temperature inversion layer by thickening the barrier *** study could be an important reference for predicting how the Indian Ocean climate will respond to future changes in shortwave radiation.

关键词： mixed layer cooling haline stratification temperature inversion ROMS model shortwave radiation Bay of Bengal eastern equatorial Indian Ocean

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Evolution of pore systems in low-maturity oil shales during thermal upgrading--Quantified by dynamic SEM and machine learning

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Petroleum Science 2024年第3期21卷 1739-1750页

作者： Jun Liu Xue Bai Derek Elsworth key laboratory of deep Underground Science and Engineering(ministry of Education) Institute of New Energy and Low-Carbon TechnologySichuan UniversityChengdu610065SichuanChina International Quantum Academy Shenzhen518048GuangdongChina Shenzhen Institute of Advanced Electronic Materials Shenzhen Institute of Advanced TechnologyChinese Academy of SciencesShenzhen518055GuangdongChina Department of Energy and Mineral Engineering Pennsylvania State University ParkPA 16802USA

In-situ upgrading by heating is feasible for low-maturity shale oil,where the pore space dynamically *** characterize this response for a heated substrate concurrently imaged by *** systematically follow the evolution of pore quantity,size(length,width and cross-sectional area),orientation,shape(aspect ratio,roundness and solidity)and their anisotropy—interpreted by machine *** indicate that heating generates new pores in both organic matter and inorganic ***,the newly formed pores are smaller than the original pores and thus reduce average lengths and widths of the bedding-parallel pore ***,the average pore lengths and widths are increased in the bedding-perpendicular ***,heating increases the cross-sectional area of pores in low-maturity oil shales,where this growth tendency fluctuates at300℃.In addition,the orientation and shape of the newly-formed heating-induced pores follow the habit of the original pores and follow the initial probability distributions of pore orientation and ***,limited anisotropy is detected in pore direction and shape,indicating similar modes of evolution both bedding-parallel and *** propose a straightforward but robust model to describe evolution of pore system in low-maturity oil shales during heating.

关键词： Low-maturity oil shale Pore elongation Organic matter pyrolysis In-situthermal upgrading Scanning electron microscopy(SEM) Machine learning

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Downward continuation of airborne gravimetry data based on Poisson integral iteration method

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Geodesy and Geodynamics 2017年第4期8卷 273-277页

作者： Xiaogang Liu Zhongmiao Sun Kang Xu Mingda Ouyang State key laboratory of Geo-Information Engineering Xi'an 710054 China Xi'an Research Institute of Surveying and Mapping Xi'an 710054 China State key laboratory of Geodesy and earth's dynamics Wuhan 430077 China Military key laboratory of Surveying Mapping and Navigation of Engineering Information Engineering University Zhengzhou 450052 China 61287 Unit of PLA Chengdu 610036 China Technical Division of Surveying and Mapping Xi'an 710054 China

The research and application of airborne gravimetry technology has become one of the hottest topics in gravity field in recent years. Downward continuation is one of the key steps in airborne gravimetry data processing, and the quality of continuation results directly influence the further application of surveying data. The Poisson integral iteration method is proposed in this paper, and the modified Poisson integral discretization formulae are also introduced in the downward continuation of airborne gravimerty data. For the test area in this paper, compared with traditional Poisson integral discretization formula, the continuation result of modified formulae is improved by 10.8 mGal, and the precision of Poisson integral iteration method is in the same amplitude as modified formulae. So the Poisson integral iteration method can reduce the discretization error of Poisson integral formula effectively. Therefore, the research achievements in this paper can be applied directly in the data processing of our country＇s airborne scalar and vector gravimetry.

关键词： Airborne gravimetry Downward continuation Poisson integral Gravity anomaly Discretization

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