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P-and SV-wave dispersion and attenuation in saturated microcracked porous rock with aligned penny-shaped fractures

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Petroleum Science 2024年第1期21卷 143-161页

作者： sheng-qing li Wen-Hao Wang Yuan-Da Su Jun-Xin Guo Xiao-Ming Tang School of Geosciences China University of Petroleum(East China)Qingdao 266580ShandongChina Laoshan National Laboratory Qingdao 266071ShangdongChina Guangdong Provincial Key Laboratory of Geophysical High-resolution Imaging Technology Southern University of Science and TechnologyShenzhen 518055GuangdongChina Department of Earth and Space Sciences Southern University of Science and TechnologyShenzhen 518055GuangdongChina

P-and SV-wave dispersion and attenuation have been extensively investigated in saturated poroelastic media with aligned ***,there are few existing models that incorporate the multiple wave attenuation mechanisms from the microscopic scale to the macroscopic ***,in this work,we developed a unified model to incorporate the wave attenuation mechanisms at different scales,which includes the microscopic squirt flow between the microcracks and pores,the mesoscopic wave-induced fluid flow between fractures and background(FB-WIFF),and the macroscopic Biot's global flow and elastic scattering(ES)from the *** Tang's modified Biot's theory and the mixed-boundary conditions,we derived the exact frequency-dependent solutions of the scattering problem for a single penny-shaped fracture with oblique incident P-and *** then developed theoretical models for a set of aligned fractures and randomly oriented fractures using the Foldy *** results indicated that microcrack squirt flow considerably influences the dispersion and attenuation of P-and SV-wave *** coupling effects of microcrack squirt flow with the FB-WIFF and ES of fractures cause much higher velocity dispersion and attenuation for P waves than for SV *** oriented fractures substantially reduce the attenuation caused by the FB-WIFF and ES,particularly for the ES attenuation of SV *** a comparison with existing models in the limiting cases and previous experimental measurements,we validated our model.

关键词： Aligned fractures P-and SV-wave Dispersion and attenuation Microcracked porous background FB-WIFF Elastic scattering Squirt flow

Extraction of reflected waves from acoustic logging data using variation mode decomposition and curvelet transform

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Petroleum Science 2024年第5期21卷 3142-3156页

作者： Fan-Tong Kong Yong-Xiang liu Xi-Hao Gu li Zhen Cheng-Ming Luo sheng-qing li Ocean College Jiangsu University of Science and TechnologyZhenjiang212100jiangsuChina School of Geosciences China University of Petroleum(East China)Qingdao266580Shandong.China State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation Chengdu University of TechnologyChengdu610059SichuanChina

Remote reflection waves, essential for acquiring high-resolution images of geological structures beyond boreholes, often suffer contamination from strong direct mode waves propagating along the ***, the extraction of weak reflected waves becomes pivotal for optimizing migration image quality. This paper introduces a novel approach to extracting reflected waves by sequentially operating in the spatial frequency and curvelet domains. Using variation mode decomposition(VMD), single-channel spatial domain signals within the common offset gather are iteratively decomposed into high-wavenumber and low-wavenumber intrinsic mode functions(IMFs). The low-wavenumber IMF is then subtracted from the overall waveform to attenuate direct mode waves. Subsequently, the curvelet transform is employed to segregate upgoing and downgoing reflected waves within the filtered curvelet domain. As a result, direct mode waves are substantially suppressed, while the integrity of reflected waves is fully preserved. The efficacy of this approach is validated through processing synthetic and field data, underscoring its potential as a robust extraction technique.

关键词： Borehole acoustic reflection imaging Variation mode decomposition Curvelet transform Weak signal extraction

Estimation of Nitrogen Fertilizer Use Efficiency in Dryland Agroecosystem

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Agricultural Sciences in China 2001年第1期 89-94页

作者： li Shi-qing li sheng-xiu College of Resources and Environmental Sciences Northwest Science and Technology University of Agriculture and Forestry Yangling Shaanxi 712100 College of Resources and Environmental Sciences Northwest Science and Technology University of Agriculture and Forestry Yangling Shaanxi 712100

A field trial was carried out to study the nitrogen fertilizer recovery by four crops in succession in manurial loess soil in Yangling. The results showed that the nitrogen fertilizer not only had the significant effects on the first crop , but also had longer residual effects, even on the fourth crop. The average apparent nitrogen fertilizer recovery by the first crop was 31.7%, and the accumulative nitrogen recovery by the 4 crops was high as 62.3%, and the latter was double as the former. It is quite clear that the nitrogen fertilizer recovery by the first crop was not reliable for estimating the nitrogen fertilizer unless the residual effect of nitrogen fertilizer was included.

关键词： Dry farming Ecological systen of farmland Nitrogen fertilizer recovery Residual effect

Percutaneous pulmonary artery biodegradable stent:a new armament to fight pulmonary artery stenosis?

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Chinese Medical Journal 2020年第19期133卷 2389-2391页

作者： Hai Zou sheng-qing li Department of Respiratory Medicine Huashan HospitalFudan UniversityShanghai 200040China

To the Editor:Pulmonary artery stenosis can be caused by numerous factors,such as tetralogy of Fallot,pulmonary atresia,tricuspid atresia with pulmonary artery stenosis,atresia combined with another congenital heart disease and pulmonary circulation dysplasia,[1,2]William syndrome,and Alagille ***,pulmonary artery branch stenosis can be the consequence of some genetic metabolic diseases,such as congenital rubella.[3]Most cases of pulmonary stenosis require surgical intervention.

关键词： metabolic branch consequence

A Note to Hutton＇s Theorem

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Journal of Mathematical Research and Exposition 2008年第2期28卷 429-434页

作者： FU Wen qing li sheng Gang College of Mathematics and Information Science Shaanxi Normal University Shaanxi 710062 China

It is proved in this paper that there is a bijection φ from J∪J to δ∪δ′which satisfies：（1）φ｜J：（J,belong to）→（δ′,≤）is a frame isomorphism;（2）φ｜J^′：（J^′,belong to）→（δ＇,≤）is a coframe isomorphism,where J is the ordinary topology on[0,1],δis the ordinary L-topology on L-unit interval I（L）,and L is a frame with an order-reversing *** result improves Theorem 3 in Hutton＇s paper.

关键词： L-unit interval ordinary topology meet-preserving mapping join-preserving mapping

Tea Seed and Its Bioactive Functions

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茶叶 2013年第4期39卷 317-320页

作者： Yue-Rong liang qing-sheng li Xin-Qiang Zheng Zhejiang university Tea Research Institute

Tea seed is a byproduct in tea production and also a source of nutritional and bioactive *** have been studies showing that extracts of tea seeds offered many physiological functions including anti-inflammatory,anti-oxidant,anti-tumor,anti-obesity,hepatoprotective and gastroprotective *** tea seed oil is also an acceptable biodiesel and the saponin-rich tea seed meal can be used as vermicide to expel earthworms from the soil of golf courses and sports *** bioactive functions of tea seed extracts and their potential uses in agricultural and industrial sectors were reviewed in the present paper.

关键词：生物活性化合物茶籽油高尔夫球场茶叶生产生理功能保护作用生物柴油工业部门

Plasmonic tandem heterojunctions enable high-efficiency charge transfer for broad spectrum photocatalytic hydrogen production

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Journal of Energy Chemistry 2025年第1期100卷 710-720页

作者： Wenxuan Chen Xiu-qing Qiao Guo Hui Bojing Sun Dongfang Hou Meidi Wang Xueqian Wu Tao Wu Dong-sheng li College of Materials and Chemical Engineering Key Laboratory of Inorganic Nonmetallic Crystalline and Energy Conversion Materials China Three Gorges University Hubei Three Gorges Laboratory College of Chemistry and Materials Science and Guangdong Provincial Key Laboratory of Supramolecular Coordination Chemistry Jinan University

Rational engineering of semiconductor photocatalysts for efficient hydrogen production is of great significance but still challenging,primarily due to the limitations in charge transfer ***,a fascinating plasmonic tandem heterojunction with the hc-CdS/Mo2C@C heterostructure is aimfully prepared for effectively promoting the charge separation kinetics of the CdS photocatalyst via the synergistic strategy of phase junction,Schottky junction,and photothermal *** difference in atomic configuration between cubic-CdS （c-CdS） and hexagonal-CdS （h-CdS） leads to effective charge separation through a typical Ⅱ charge transfer mechanism,and plasmonic Schottky junction further extracts the electrons in the hc-CdS phase junction to realize gradient charge ***,the photothermal effect of Mo2C@C helps to expand the light absorption,accelerate charge transfer kinetics,and reduce the hydrogen evolution energy *** carbon layer provides a fast channel for charge transfer and protects the photocatalyst from *** a result,the optimized hc-CMC photocatalyst exhibits a significantly high photocatalytic H2production activity of 28.63 mmol/g/h and apparent quantum efficiency of 61.8%,surpassing most of the reported *** study provides a feasible strategy to enhance the charge transfer kinetics and photocatalytic activity of CdS by constructing plasmonic tandem heterogeneous junctions.

关键词： Cadmium sulfide

Role of hypoxia-induced VEGF in blood-spinal cord barrier disruption in chronic spinal cord injury

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Chinese Journal of Traumatology 2015年第5期18卷 293-295页

作者： Hou-qing Long Guang-sheng li Xing Cheng Jing-Hui Xu Fo-Bao li Department of Spinal Surgery The First Affiliated Hospital of Sun Yat-Sen University China

Chronic spinal cord lesions （CSCL） which result in irreversible neurologic deficits remain one of tbe most devastating clinical problems. Its patbophysiological mechanism has not been fully clarified. As a crucial factor in the outcomes following traumatic spinal cord injury （SCI）, the blood-spinal cord barrier （BSCB） disruption is considered as an important pathogenic factor contributing to the neurologic impairment in SCI. Vascular endothelial growth factor （VEGF） is a multirole element in the spinal cord vascular event. On one hand, VEGF administrations can result in rise of BSCB permeability in acute or sub-acute periods and even last for chronic process. On the other band, VEGF is regarded to be correlated with anglo- genesis, neurogenesis and improvement of locomotor ability. Hypoxia inducible factor-I （HIFq） is a primary regulator of VEGF during hypoxic conditions. Therefore, hypoxia-mediated up-regulation of VEGF may play multiple roles in the BSCB disruption and react on functional restoration of CSCL. The purpose of this article is to further explore the relationship among HIF-1, hypoxia-mediated VEGF and BSCB dysfunction, and investigate the roles of these elements on CSCL.

关键词： VEGF Blood-spinal cord barrier Chronic spinal cord lesions

Molecular Cloning of a Cellulose Synthase Gene PtoCesA1 from Populus tomentosa and Its Genetic Transformation in Tobacco

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Forestry Studies in China 2005年第4期7卷 5-10页

作者： li Chun-xiu Zhang Shou-gong Wang Yang-dong Shi sheng-qing Qi li-wang Laboratory of Cell Biology Research Institute of Forestry Chinese Academy of Forestry Beijing 100091 P. R. China

A 3 125 bp cellulose synthase gene, PtoCesA1, which has a 98% identity to PtrCesA1 from Populus tremuloides, was cloned from cDNA prepared from secondary xylem of P tomentosa. Four anti-expression vectors with different fragments of PtoCesAl, named as pBIPF, pBICC1, pBIPR and pBIBR, were constructed. Some traits of transformed tobacco of pBICC1, pBIPR and pBIBR differed from wild types, such as small leaves, ＂dwarf＂ phenotype and thinner xylem and fiber cell walls than wild plants consistent with a loss of cellulose. It indicated that the growth of transgenic tobacco was restrained by the expression of anti-PtoCesA1. Transgenic tobacco was obtained and the contents of cellulose and lignin were analyzed as well as the width and length of fiber cells, and xylem thickness for both transgenic and control plants. Transformed tobacco showed a different phenotype from control plants and it implied that PtoCesA1 was essential for the cellulose biosynthesis in poplar stems.

关键词： Populus tomentosa cellulose synthase transgenic tabacco PtoCesA1