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A method of reconstructing 3D model from 2D geological cross-section based on self-adaptive spatial sampling:A case study of Cretaceous McMurray reservoirs in a block of Canada 被引量:1
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作者 WANG Lixin YIN Yanshu +6 位作者 WANG Hui ZHANG Changmin FENG Wenjie LIU Zhenkun WANG Pangen CHENG Lifang LIU Jiong 《Petroleum Exploration and Development》 CSCD 2021年第2期407-420,共14页
An orthogonal 2D training image is constructed from the geological analysis results of well logs and sedimentary facies;the 2 D probabilities in three directions are obtained through linear pooling method and then agg... An orthogonal 2D training image is constructed from the geological analysis results of well logs and sedimentary facies;the 2 D probabilities in three directions are obtained through linear pooling method and then aggregated by the logarithmic linear pooling to determine the 3 D multi-point pattern probabilities at the unknown points,to realize the reconstruction of a 3 D model from 2D cross-section.To solve the problems of reducing pattern variability in the 2 D training image and increasing sampling uncertainty,an adaptive spatial sampling method is introduced,and an iterative simulation strategy is adopted,in which sample points from the region with higher reliability of the previous simulation results are extracted to be additional condition points in the following simulation to improve the pattern probability sampling stability.The comparison of lateral accretion layer conceptual models shows that the reconstructing algorithm using self-adaptive spatial sampling can improve the accuracy of pattern sampling and rationality of spatial structure characteristics,and accurately reflect the morphology and distribution pattern of the lateral accretion layer.Application of the method in reconstructing the meandering river reservoir of the Cretaceous McMurray Formation in Canada shows that the new method can accurately reproduce the shape,spatial distribution pattern and development features of complex lateral accretion layers in the meandering river reservoir under tide effect.The test by sparse wells shows that the simulation accuracy is above 85%,and the coincidence rate of interpretation and prediction results of newly drilled horizontal wells is up to 80%. 展开更多
关键词 geological modeling two-dimensional cross-section three-dimensional model probability aggregation lateral accretion layer multiple-point geostatistics self-adaptive spatial sampling
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Automatic Generation Method of Geological Cross-Sections in Dredging Engineering Based on 3D Solid NURBS Models 被引量:1
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作者 缪正建 李明超 钟登华 《Transactions of Tianjin University》 EI CAS 2012年第6期393-400,共8页
An automatic generation method of geological cross-sections in dredging engineering based on 3D geological solid models is presented.The 3D geological models are built applying the non-uniform rational B-splines(NURBS... An automatic generation method of geological cross-sections in dredging engineering based on 3D geological solid models is presented.The 3D geological models are built applying the non-uniform rational B-splines(NURBS) technique,and a 2D profile can be calculated and generated automatically through Boolean operation to meet the demands of dredging projects.Moreover,an automatic marking method for geological attributes is put forward based on database technology,and the geological attributes include the profile name,scale,horizontal and vertical relative coordinates,geological lithology,and 2D standard lithology legend.At the same time,the automatic marking method can also provide an interactive mode for geological engineers to edit and modify the profile in the modeling system.Practical engineering applications show that the automatic generation method is a simple,flexible,fast and precise visual graphics rendering process that can create 2D standard profiles automatically and efficiently.This method also provides a convenient support tool for geological engineering digital analysis. 展开更多
关键词 dredging engineering 3D geological solid modeling automatic generation NURBS
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Optimization Design of the Multi-Layer Cross-Sectional Layout of An Umbilical Based on the GA-GLM 被引量:1
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作者 YANG Zhi-xun YIN Xu +5 位作者 FAN Zhi-rui YAN Jun LU Yu-cheng SU Qi MAO Yandong WANG Hua-lin 《China Ocean Engineering》 SCIE EI CSCD 2024年第2期247-254,共8页
Marine umbilical is one of the key equipment for subsea oil and gas exploitation,which is usually integrated by a great number of different functional components with multi-layers.The layout of these components direct... Marine umbilical is one of the key equipment for subsea oil and gas exploitation,which is usually integrated by a great number of different functional components with multi-layers.The layout of these components directly affects manufacturing,operation and storage performances of the umbilical.For the multi-layer cross-sectional layout design of the umbilical,a quantifiable multi-objective optimization model is established according to the operation and storage requirements.Considering the manufacturing factors,the multi-layering strategy based on contact point identification is introduced for a great number of functional components.Then,the GA-GLM global optimization algorithm is proposed combining the genetic algorithm and the generalized multiplier method,and the selection operator of the genetic algorithm is improved based on the steepest descent method.Genetic algorithm is used to find the optimal solution in the global space,which can converge from any initial layout to the feasible layout solution.The feasible layout solution is taken as the initial value of the generalized multiplier method for fast and accurate solution.Finally,taking umbilicals with a great number of components as examples,the results show that the cross-sectional performance of the umbilical obtained by optimization algorithm is better and the solution efficiency is higher.Meanwhile,the multi-layering strategy is effective and feasible.The design method proposed in this paper can quickly obtain the optimal multi-layer cross-sectional layout,which replaces the manual design,and provides useful reference and guidance for the umbilical industry. 展开更多
关键词 UMBILICAL cross-sectional layout MULTI-LAYERS GA-GLM optimization
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Estimation of the anisotropy of hydraulic conductivity through 3D fracture networks using the directional geological entropy 被引量:1
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作者 Chuangbing Zhou Zuyang Ye +2 位作者 Chi Yao Xincheng Fan Feng Xiong 《International Journal of Mining Science and Technology》 SCIE EI CAS CSCD 2024年第2期137-148,共12页
With an extension of the geological entropy concept in porous media,the approach called directional entrogram is applied to link hydraulic behavior to the anisotropy of the 3D fracture networks.A metric called directi... With an extension of the geological entropy concept in porous media,the approach called directional entrogram is applied to link hydraulic behavior to the anisotropy of the 3D fracture networks.A metric called directional entropic scale is used to measure the anisotropy of spatial order in different directions.Compared with the traditional connectivity indexes based on the statistics of fracture geometry,the directional entropic scale is capable to quantify the anisotropy of connectivity and hydraulic conductivity in heterogeneous 3D fracture networks.According to the numerical analysis of directional entrogram and fluid flow in a number of the 3D fracture networks,the hydraulic conductivities and entropic scales in different directions both increase with spatial order(i.e.,trace length decreasing and spacing increasing)and are independent of the dip angle.As a result,the nonlinear correlation between the hydraulic conductivities and entropic scales from different directions can be unified as quadratic polynomial function,which can shed light on the anisotropic effect of spatial order and global entropy on the heterogeneous hydraulic behaviors. 展开更多
关键词 3D fracture network geological entropy Directional entropic scale ANISOTROPY Hydraulic conductivity
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Association between triglyceride-glucose index and colorectal polyps:A retrospective cross-sectional study 被引量:1
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作者 Ya-Jie Teng Ying-Xue Yang +5 位作者 Jing-Jing Yang Qiu-Yan Lu Jia-Yi Shi Jian-Hao Xu Jie Bao Qing-Hua Wang 《World Journal of Gastrointestinal Endoscopy》 2024年第2期55-63,共9页
BACKGROUND Colorectal polyps(CPs)are frequently occurring abnormal growths in the colorectum,and are a primary precursor of colorectal cancer(CRC).The triglyceride-glucose(TyG)index is a novel marker that assesses met... BACKGROUND Colorectal polyps(CPs)are frequently occurring abnormal growths in the colorectum,and are a primary precursor of colorectal cancer(CRC).The triglyceride-glucose(TyG)index is a novel marker that assesses metabolic health and insulin resistance,and has been linked to gastrointestinal cancers.AIM To investigate the potential association between the TyG index and CPs,as the relation between them has not been documented.METHODS A total of 2537 persons undergoing a routine health physical examination and colonoscopy at The First People's Hospital of Kunshan,Jiangsu Province,China,between January 2020 and December 2022 were included in this retrospective cross-sectional study.After excluding individuals who did not meet the eligibility criteria,descriptive statistics were used to compare characteristics between patients with and without CPs.Logistic regression analyses were conducted to determine the associations between the TyG index and the prevalence of CPs.The TyG index was calculated using the following formula:Ln[triglyceride(mg/dL)×glucose(mg/dL)/2].The presence and types of CPs was determined based on data from colonoscopy reports and pathology reports.RESULTS A nonlinear relation between the TyG index and the prevalence of CPs was identified,and exhibited a curvilinear pattern with a cut-off point of 2.31.A significant association was observed before the turning point,with an odds ratio(95% confidence interval)of 1.70(1.40,2.06),P<0.0001.However,the association between the TyG index and CPs was not significant after the cut-off point,with an odds ratio(95% confidence interval)of 0.57(0.27,1.23),P=0.1521.CONCLUSION Our study revealed a curvilinear association between the TyG index and CPs in Chinese individuals,suggesting its potential utility in developing colonoscopy screening strategies for preventing CRC. 展开更多
关键词 Triglyceride-glucose index Colorectal polyps Colorectal cancer Insulin resistance cross-sectional study
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Mental health and insomnia problems in healthcare workers after the COVID-19 pandemic:A multicenter cross-sectional study 被引量:1
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作者 Wei Ding Min-Zhong Wang +8 位作者 Xian-Wei Zeng Zhen-Hua Liu Yao Meng Hui-Ting Hu Yuan Zhang Yu-Guang Guan Fan-Gang Meng Jian-Guo Zhang Shu Wang 《World Journal of Psychiatry》 SCIE 2024年第5期704-714,共11页
BACKGROUND Healthcare workers(HCWs)are at increased risk of contracting coronavirus disease 2019(COVID-19)as well as worsening mental health problems and insomnia.These problems can persist for a long period,even afte... BACKGROUND Healthcare workers(HCWs)are at increased risk of contracting coronavirus disease 2019(COVID-19)as well as worsening mental health problems and insomnia.These problems can persist for a long period,even after the pandemic.However,less is known about this topic.AIM To analyze mental health,insomnia problems,and their influencing factors in HCWs after the COVID-19 pandemic.METHODS This multicenter cross-sectional,hospital-based study was conducted from June 1,2023 to June 30,2023,which was a half-year after the end of the COVID-19 emergency.Region-stratified population-based cluster sampling was applied at the provincial level for Chinese HCWs.Symptoms such as anxiety,depression,and insomnia were evaluated by the Generalized Anxiety Disorder-7,Patient Health Questionnaire-9,and Insomnia Severity Index.Factors influencing the symptoms were identified by multivariable logistic regression.RESULTS A total of 2000 participants were invited,for a response rate of 70.6%.A total of 1412 HCWs[618(43.8%)doctors,583(41.3%)nurses and 211(14.9%)nonfrontline],254(18.0%),231(16.4%),and 289(20.5%)had symptoms of anxiety,depression,and insomnia,respectively;severe symptoms were found in 58(4.1%),49(3.5%),and 111(7.9%)of the participants.Nurses,female sex,and hospitalization for COVID-19 were risk factors for anxiety,depression,and insomnia symptoms;moreover,death from family or friends was a risk factor for insomnia symptoms.During the COVID-19 outbreak,most[1086(76.9%)]of the participating HCWs received psychological interventions,while nearly all[994(70.4%)]of them had received public psychological education.Only 102(7.2%)of the HCWs received individual counseling from COVID-19.CONCLUSION Although the mental health and sleep problems of HCWs were relieved after the COVID-19 pandemic,they still faced challenges and greater risks than did the general population.Identifying risk factors would help in providing targeted interventions.In addition,although a major proportion of HCWs have received public psychological education,individual interventions are still insufficient. 展开更多
关键词 COVID-19 Mental health Psychological symptoms INSOMNIA Sleep disorders cross-sectional study Epidemiological study
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Method for evaluation of geological strength index of carbonate cliff rocks:Coupled hyperspectral-digital borehole image technique 被引量:1
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作者 Haiqing Yang Guizhong Huang +3 位作者 Chiwei Chen Yong Yang Qi Wang Xionghui Dai 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2024年第10期4204-4215,共12页
The deterioration of unstable rock mass raised interest in evaluating rock mass quality.However,the traditional evaluation method for the geological strength index(GSI)primarily emphasizes the rock structure and chara... The deterioration of unstable rock mass raised interest in evaluating rock mass quality.However,the traditional evaluation method for the geological strength index(GSI)primarily emphasizes the rock structure and characteristics of discontinuities.It ignores the influence of mineral composition and shows a deficiency in assessing the integrity coefficient.In this context,hyperspectral imaging and digital panoramic borehole camera technologies are applied to analyze the mineral content and integrity of rock mass.Based on the carbonate mineral content and fissure area ratio,the strength reduction factor and integrity coefficient are calculated to improve the GSI evaluation method.According to the results of mineral classification and fissure identification,the strength reduction factor and integrity coefficient increase with the depth of rock mass.The rock mass GSI calculated by the improved method is mainly concentrated between 40 and 60,which is close to the calculation results of the traditional method.The GSI error rates obtained by the two methods are mostly less than 10%,indicating the rationality of the hyperspectral-digital borehole image coupled evaluation method.Moreover,the sensitivity of the fissure area ratio(Sr)to GSI is greater than that of the strength reduction factor(a),which means the proposed GSI is suitable for rocks with significant fissure development.The improved method reduces the influence of subjective factors and provides a reliable index for the deterioration evaluation of rock mass. 展开更多
关键词 Hyperspectral image Digital panoramic borehole image geological strength index Carbonate rock mass Quantitative evaluation
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Preface to the special issue dedicated to the 37^(th) International Geological Congress
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作者 Zi-guo Hao 《China Geology》 CAS CSCD 2024年第3期381-381,共1页
The 37^(th) International Geological Congress,a premier forum held quadrennially and eagerly anticipated by geologists and geology enthusiasts worldwide,will take place from August 25 to 31,2024 in Busan,Republic of K... The 37^(th) International Geological Congress,a premier forum held quadrennially and eagerly anticipated by geologists and geology enthusiasts worldwide,will take place from August 25 to 31,2024 in Busan,Republic of Korea.To celebrate this grand event,China Geology,a multidisciplinary geosciences journal sponsored by China Geological Survey and Chinese Academy of Geological Sciences(where the Secretariat of the International Union of Geological Sciences is currently located),presents this special issue and extends our best wishes for the success of the conference! 展开更多
关键词 geologY geological JOURNAL
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GeoNER:Geological Named Entity Recognition with Enriched Domain Pre-Training Model and Adversarial Training
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作者 MA Kai HU Xinxin +4 位作者 TIAN Miao TAN Yongjian ZHENG Shuai TAO Liufeng QIU Qinjun 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2024年第5期1404-1417,共14页
As important geological data,a geological report contains rich expert and geological knowledge,but the challenge facing current research into geological knowledge extraction and mining is how to render accurate unders... As important geological data,a geological report contains rich expert and geological knowledge,but the challenge facing current research into geological knowledge extraction and mining is how to render accurate understanding of geological reports guided by domain knowledge.While generic named entity recognition models/tools can be utilized for the processing of geoscience reports/documents,their effectiveness is hampered by a dearth of domain-specific knowledge,which in turn leads to a pronounced decline in recognition accuracy.This study summarizes six types of typical geological entities,with reference to the ontological system of geological domains and builds a high quality corpus for the task of geological named entity recognition(GNER).In addition,Geo Wo BERT-adv BGP(Geological Word-base BERTadversarial training Bi-directional Long Short-Term Memory Global Pointer)is proposed to address the issues of ambiguity,diversity and nested entities for the geological entities.The model first uses the fine-tuned word granularitybased pre-training model Geo Wo BERT(Geological Word-base BERT)and combines the text features that are extracted using the Bi LSTM(Bi-directional Long Short-Term Memory),followed by an adversarial training algorithm to improve the robustness of the model and enhance its resistance to interference,the decoding finally being performed using a global association pointer algorithm.The experimental results show that the proposed model for the constructed dataset achieves high performance and is capable of mining the rich geological information. 展开更多
关键词 geological named entity recognition geological report adversarial training confrontation training global pointer pre-training model
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Geological conditions and reservoir characteristics of various shales in major shalehosted regions of China
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作者 Shu-jing Bao Tian-xu Guo +6 位作者 Jin-tao Yin Wei-bin Liu Sheng-jian Wang Hao-han Li Zhi Zhou Shi-zhen Li Xiang-lin Chen 《China Geology》 CAS CSCD 2024年第1期138-149,共12页
China is home to shales of three facies:Marine shale,continental shale,and marine-continental transitional shale.Different types of shale gas are associated with significantly different formation conditions and major ... China is home to shales of three facies:Marine shale,continental shale,and marine-continental transitional shale.Different types of shale gas are associated with significantly different formation conditions and major controlling factors.This study compared the geological characteristics of various shales and analyzed the influences of different parameters on the formation and accumulation of shale gas.In general,shales in China’s several regions exhibit high total organic carbon(TOC)contents,which lays a sound material basis for shale gas generation.Marine strata generally show high degrees of thermal evolution.In contrast,continental shales manifest low degrees of thermal evolution,necessitating focusing on areas with relatively high degrees of thermal evolution in the process of shale gas surveys for these shales.The shales of the Wufeng and Silurian formations constitute the most favorable shale gas reservoirs since they exhibit the highest porosity among the three types of shales.These shales are followed by those in the Niutitang and Longtan formations.In contrast,the shales of the Doushantuo,Yanchang,and Qingshankou formations manifest low porosities.Furthermore,the shales of the Wufeng and Longmaxi formations exhibit high brittle mineral contents.Despite a low siliceous mineral content,the shales of the Doushantuo Formation feature a high carbonate mineral content,which can increase the shales’brittleness to some extent.For marine-continental transitional shales,where thin interbeds of tight sandstone with unequal thicknesses are generally found,it is recommended that fracturing combined with drainage of multiple sets of lithologic strata should be employed to enhance their shale gas production. 展开更多
关键词 Shale gas Marine shale Continental shale Marine-continental transitional shale Neoproterozoic-Cretaceous strata geological conditions Reservoir characteristics Petroleum geological survey engineering
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The State of Geological Sciences in the USSR by the Mid-Twentieth Century
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作者 Ivan Petrovich VTOROV 《Chinese Annals of History of Science and Technology》 2024年第1期125-130,共6页
The November 1948 open session of the Institute of Geological Sciences AS USSR was previously unknown,in contrast to the August 1948 session of VASKhNIL.The publication of the transcript of the session of geologists i... The November 1948 open session of the Institute of Geological Sciences AS USSR was previously unknown,in contrast to the August 1948 session of VASKhNIL.The publication of the transcript of the session of geologists is based on the original verified transcript from the Geological Institute and the Archive RAS.It presented reports on the main scientific directions of geology:stratigraphy,the Quaternary geology,lithology,geotectonics,petrography and petrology,mineralogy and geochemistry,and the geology of ore and coal deposits.This thick book details all the Q&A sessions,discussions of theories,methods,and practice among the leading Soviet geoscientists.The session and its resolution describe the situation and development of geology in the USSR in the mid-twentieth century as well as the collateral impact of the Lysenko affair on the earth sciences in the USSR. 展开更多
关键词 history of geology geological sciences book review 1948 session VASKhNIL 1948 session of the Institute of geological Sciences AS USSR
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Association between Residential Greenness and Cardiometabolic Risk Factors among Adults in Rural Xinjiang Uygur Autonomous Region,China:A Cross-Sectional Study
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作者 Leyao Jian Bo Yang +10 位作者 Rulin Ma Shuxia Guo Jia He Yu Li Yusong Ding Dongsheng Rui Yidan Mao Xin He Xueying Sun Shengyu Liao Heng Guo 《Biomedical and Environmental Sciences》 SCIE CAS CSCD 2024年第10期1184-1194,共11页
Objective This study aimed to explore the relationships between residential greenness and cardiometabolic risk factors among rural adults in Xinjiang Uygur Autonomous Region(Xinjiang)and thus provide a theoretical bas... Objective This study aimed to explore the relationships between residential greenness and cardiometabolic risk factors among rural adults in Xinjiang Uygur Autonomous Region(Xinjiang)and thus provide a theoretical basis and data support for improving the health of residents in this region.Methods We recruited 9,723 adult rural residents from the 51st Regiment of the Third Division of the Xinjiang Production and Construction Corps in September 2016.The normalized difference vegetation index(NDVI)was used to estimate residential greenness.The generalized linear mixed model(GLMM)was used to examine the association between residential greenness and cardiometabolic risk factors.Results Higher residential greenness was associated with lower cardiometabolic risk factor prevalence.After adjustments were made for age,sex,education,and marital status,for each interquartile range(IQR)increase of NDVI500-m,the risk of hypertension was reduced by 10.3%(OR=0.897,95%CI=0.836-0.962),the risk of obesity by 20.5%(OR=0.795,95%CI=0.695-0.910),the risk of type 2 diabetes by 15.1%(OR=0.849,95%CI=0.740-0.974),and the risk of dyslipidemia by 10.5%(OR=0.895,95%CI=0.825-0.971).Risk factor aggregation was reduced by 20.4%(OR=0.796,95%CI=0.716-0.885)for the same.Stratified analysis showed that NDVI500-m was associated more strongly with hypertension,dyslipidemia,and risk factor aggregation among male participants.The association of NDVI500-m with type 2 diabetes was stronger among participants with a higher education level.PM10 and physical activity mediated 1.9%-9.2%of the associations between NDVI500-m and obesity,dyslipidemia,and risk factor aggregation.Conclusion Higher residential greenness has a protective effect against cardiometabolic risk factors among rural residents in Xinjiang.Increasing the area of green space around residences is an effective measure to reduce the burden of cardiometabolic-related diseases among rural residents in Xinjiang. 展开更多
关键词 Green space Cardiometabolic risk factors cross-sectional study Rural adults
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Evaluating the characteristics of geological structures in karst groundwater inflow, Nowsud Tunnel
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作者 BAYAT Narges SADEGHI Erfan NASSERY Hamid Reza 《Journal of Mountain Science》 SCIE CSCD 2024年第10期3434-3452,共19页
Highly permeable geological structures such as dissolution channels, open fractures, and faults create environmental challenges regard to hydrological and hydrogeological aspects of underground construction, often cau... Highly permeable geological structures such as dissolution channels, open fractures, and faults create environmental challenges regard to hydrological and hydrogeological aspects of underground construction, often causing significant groundwater inflow during drilling due to the limitations of empirical and analytical methods. This study aims to identify the geological factors influencing water flow into the tunnel. High-flow zones' geological features have been identified and examined for this purpose. According to the geological complexity of the Nowsud tunnel, presence of different formations with different permeability and karstification have led to a high volume of underground inflow water (up to 4700 L/s) to the tunnel. The Nowsud tunnel faces significant geological and hydrogeological challenges due to its passage through the Ilam formation's LI2 unit, characterized by dissolution channels, faults, and fractures. The highest inflow rate (4700 L/s) occurred in the Hz-9 zone within the Zimkan anticline. The relationship between geological features and groundwater inflow indicates that anticlines are more susceptible to inflow than synclines. Additionally, different types of faults exhibit varying hydraulic effects, with strike-slip faults having the most significant impact on groundwater inflow, thrust faults conducting less water into the tunnel, and inflow through normal faults being negligible compared to the other two types of faults. The novelty of this paper lies in its detailed analysis of geological features influencing groundwater inflow into the Nowsud tunnel, providing empirical data on high-flow zones and differentiating the hydraulic effects of various fault types, which enhances the understanding and prediction of groundwater inflow in underground constructions. 展开更多
关键词 geological structures Groundwater inflow HYDROgeologY Nowsud tunnel KARST
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Wideband radar cross-section reduction by a double-layer-plasma-based metasurface
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作者 赵智明 李小平 +2 位作者 董果香 刘旭 牟相超 《Plasma Science and Technology》 SCIE EI CAS CSCD 2024年第6期159-168,共10页
Reduction of the radar cross-section(RCS) is the key to stealth technology. To improve the RCS reduction effect of the designed checkerboard metasurface and overcome the limitation of thinlayer plasma in RCS reduction... Reduction of the radar cross-section(RCS) is the key to stealth technology. To improve the RCS reduction effect of the designed checkerboard metasurface and overcome the limitation of thinlayer plasma in RCS reduction technology, a double-layer-plasma-based metasurface—composed of a checkerboard metasurface, a double-layer plasma and an air gap between them—was investigated. Based on the principle of backscattering cancellation, we designed a checkerboard metasurface composed of different artificial magnetic conductor units;the checkerboard metasurface can reflect vertically incident electromagnetic(EM) waves in four different inclined directions to reduce the RCS. Full-wave simulations confirm that the doublelayer-plasma-based metasurface can improve the RCS reduction effect of the metasurface and the plasma. This is because in a band lower than the working band of the metasurface, the RCS reduction effect is mainly improved by the plasma layer. In the working band of the metasurface,impedance mismatching between the air gap and first plasma layer and between first and second plasma layers cause the scattered waves to become more dispersed, so the propagation path of the EM waves in the plasma becomes longer, increasing the absorption of the EM waves by the plasma. Thus, the RCS reduction effect is enhanced. The double-layer-plasma-based metasurface can be insensitive to the polarization of the incoming EM waves, and can also maintain a satisfactory RCS reduction band when the incident waves are oblique. 展开更多
关键词 stealth technology radar cross-section(RCS)reduction backscattering cancellation double-layer-plasma-based metasurface
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Scale-space effect and scale hybridization in image intelligent recognition of geological discontinuities on rock slopes
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作者 Mingyang Wang Enzhi Wang +1 位作者 Xiaoli Liu Congcong Wang 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2024年第4期1315-1336,共22页
Geological discontinuity(GD)plays a pivotal role in determining the catastrophic mechanical failure of jointed rock masses.Accurate and efficient acquisition of GD networks is essential for characterizing and understa... Geological discontinuity(GD)plays a pivotal role in determining the catastrophic mechanical failure of jointed rock masses.Accurate and efficient acquisition of GD networks is essential for characterizing and understanding the progressive damage mechanisms of slopes based on monitoring image data.Inspired by recent advances in computer vision,deep learning(DL)models have been widely utilized for image-based fracture identification.The multi-scale characteristics,image resolution and annotation quality of images will cause a scale-space effect(SSE)that makes features indistinguishable from noise,directly affecting the accuracy.However,this effect has not received adequate attention.Herein,we try to address this gap by collecting slope images at various proportional scales and constructing multi-scale datasets using image processing techniques.Next,we quantify the intensity of feature signals using metrics such as peak signal-to-noise ratio(PSNR)and structural similarity(SSIM).Combining these metrics with the scale-space theory,we investigate the influence of the SSE on the differentiation of multi-scale features and the accuracy of recognition.It is found that augmenting the image's detail capacity does not always yield benefits for vision-based recognition models.In light of these observations,we propose a scale hybridization approach based on the diffusion mechanism of scale-space representation.The results show that scale hybridization strengthens the tolerance of multi-scale feature recognition under complex environmental noise interference and significantly enhances the recognition accuracy of GD.It also facilitates the objective understanding,description and analysis of the rock behavior and stability of slopes from the perspective of image data. 展开更多
关键词 Image processing geological discontinuities Deep learning MULTI-SCALE Scale-space theory Scale hybridization
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Microscopic characteristics and geological significance of pyrite in shales of the Wufeng-Longmaxi formations,southeastern Chongqing,China
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作者 Xiao Cai Wei Xia +6 位作者 Yuxia Liu Shunzhou Liao Lei Zhang Weixue Hu Li Liu Wei Li Fanwu Zeng 《Energy Geoscience》 EI 2024年第3期203-211,共9页
Shales of the Wufeng-Longmaxi formations in the basin-margin transition zone of southeastern Chongqing,China are characterized by high organic matter content and a significant presence of pyrite development.By examini... Shales of the Wufeng-Longmaxi formations in the basin-margin transition zone of southeastern Chongqing,China are characterized by high organic matter content and a significant presence of pyrite development.By examining numerous scanning electron microscope(SEM)images and considering the crystal and aggregate characteristics of minerals,we identified four types of pyrite in the study area:euhedral crystals,irregular aggregates,framboidal aggregates,and metasomatized organisms.Among these types,framboidal aggregates are the most prevalent.The formation mechanism of framboidal pyrite can be categorized into inorganic and organic origins.As inferred from the pyrite characteristics in the study area,the formation mechanism of the metasomatized organisms aligns with the biologically induced mineralization mode of organic origin,whereas the framboidal aggregates are more associated with the biologically controlled mineralization mode of organic origin.This underscores a close relationship between the pyrite formation and organic matter,which in turn indicates that an organic origin is more consistent with the pyrite characteristics observed in this study area.The pyrite morphology can reflect reactive iron concentration.Euhedral pyrite crystals tend to form under a low reactive iron concentration,whereas the formation of framboidal pyrite requires a high reactive iron concentration.Additionally,the type and grain size of pyrite aggregates can reflect variations in the redox conditions of the depositional environment.Pyrite produces positive effects on reservoir storage space,with intercrystalline organic pores,intercrystalline pores,and mold pores associated with pyrite contributing greatly to the storage spaces. 展开更多
关键词 Wufeng-Longmaxi formations SHALE PYRITE Microscopic characteristics geological significance
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Dyslipidemia in Adults with Type 2 Diabetes in a Rural Community in Ganadougou, Mali: A Cross-Sectional Study
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作者 Abdoulaye Diawara Djibril Mamadou Coulibaly +22 位作者 Drissa Kone Mama A. Traore Drissa Konaté Dicko S. Bazi Oumar Kassogue Djeneba Sylla Fatoumata Gniné Fofana Oudou Diabaté Mariam Traore Ibrahim Antoine Nieantao Kaly Keїta Mamadou Diarra Olivia Smith Jian Li Cheickna Cisse Talib Yusuf Abbas Crystal Zheng Segun Fatumo Kassim Traore Mamadou Wele Mahamadou Diakité Seydou O. Doumbia Jeffrey G. Shaffer 《Journal of Diabetes Mellitus》 CAS 2024年第2期133-152,共20页
Dyslipidemia is a disorder where abnormally lipid concentrations circulate in the bloodstream. The disorder is common in type 2 diabetics (T2D) and is linked with T2D comorbidities, particularly cardiovascular disease... Dyslipidemia is a disorder where abnormally lipid concentrations circulate in the bloodstream. The disorder is common in type 2 diabetics (T2D) and is linked with T2D comorbidities, particularly cardiovascular disease. Dyslipidemia in T2D is typically characterized by elevated plasma triglyceride and low high-density lipoprotein cholesterol (HDL-C) levels. There is a significant gap in the literature regarding dyslipidemia in rural parts of Africa, where lipid profiles may not be captured through routine surveillance. This study aimed to characterize the prevalence and demo-graphic profile of dyslipidemia in T2D in the rural community of Ganadougou, Mali. We performed a cross-sectional study of 104 subjects with T2D in Ganadougou between November 2021 and March 2022. Demographic and lipid profiles were collected through cross-sectional surveys and serological analyses. The overall prevalence of dyslipidemia in T2D patients was 87.5% (91/104), which did not differ by sex (P = .368). High low-density lipoprotein cholesterol (LDL-C) was the most common lipid abnormality (78.9%, [82/104]). Dyslipidemia was associated with age and hypertension status (P = .013 and.036, respectively). High total and high LDL-C parameters were significantly associated with hypertension (P = .029 and .006, respectively). In low-resource settings such as rural Mali, there is a critical need to improve infrastructure for routine dyslipidemia screening to guide its prevention and intervention approaches. The high rates of dyslipidemia observed in Gandadougou, consistent with concomitant increases in cardiovascular diseases in Africa suggest that lipid profile assessments should be incorporated into routine medical care for T2D patients in African rural settings. 展开更多
关键词 CHOLESTEROL cross-sectional Study DYSLIPIDEMIA LIPIDS MALI Type 2 Diabetes
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Cross-section distortion and springback characteristics of double-cavity aluminum profile in force controlled stretch-bending
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作者 Zhi-wen LIU Zi-xuan DONG +2 位作者 Cong-chang XU Jie YI Luo-xing LI 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2024年第8期2476-2490,共15页
3D elastic-plastic FE model for simulating the force controlled stretch-bending process of double-cavity aluminum profile was established using hybrid explicit−implicit solvent method.Considering the computational acc... 3D elastic-plastic FE model for simulating the force controlled stretch-bending process of double-cavity aluminum profile was established using hybrid explicit−implicit solvent method.Considering the computational accuracy and efficiency,the optimal choices of numerical parameters and algorithms in FE modelling were determined.The formation mechanisms of cross-section distortion and springback were revealed.The effects of pre-stretching,post-stretching,friction,and the addition of internal fillers on forming quality were investigated.The results show that the stress state of profile in stretch-bending is uniaxial with only a circumferential stress.The stress distribution along the length direction of profile is non-uniform and the maximum tensile stress is located at a certain distance away from the center of profile.As aluminum profile is gradually attached to bending die,the distribution characteristic of cross-section distortion along the length direction of profile changes from V-shape to W-shape.After unloading the forming tools,cross-section distortion decreases obviously due to the stress relaxation,with a maximum distortion difference of 13%before and after unloading.As pre-stretching and post-stretching forces increase,cross-section distortion increases gradually,while springback first decreases and then remains unchanged.With increasing friction between bending die and profile,cross-section distortion slightly decreases,while springback increases.Cross-section distortion decreases by 83%with adding PVC fillers into the cavities of profile,while springback increases by 192.2%. 展开更多
关键词 hollow aluminum profile force controlled stretch-bending numerical parameters springback analysis approach cross-section distortion SPRINGBACK process parameters
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Prediction of favorable geological storage areas based on sedimentary characteristics:A case study on the northeastern Ordos Basin,China
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作者 Yue Zhao Qiang Xu +6 位作者 Song Du Yang Zhang Tengzhuo Zhang Yinglin Fan Yan Ding Sitong Song Xinxin Feng 《Energy Geoscience》 EI 2024年第4期187-197,共11页
The Ordos Basin is a large cratonic basin with stable deposition in Northwest China.Given its mostly stable subsidence background and the urgent need for saline water disposal and carbon dioxide storage in the coal mi... The Ordos Basin is a large cratonic basin with stable deposition in Northwest China.Given its mostly stable subsidence background and the urgent need for saline water disposal and carbon dioxide storage in the coal mining and coal chemical industries,the Ordos Basin has been chosen as a pilot demonstration site for carbon dioxide and saline water storage in China.However,few studies have been made to evaluate the sedimentary and sequence stratigraphy characteristics of this region,as well as their influence on carbon dioxide and saline water storage potential.To address this research gap,we conducted a sedimentary study of the Lower Triassic Liujiagou Formation in the northeastern Ordos Basin utilizing the stratigraphy theory,laboratory test analysis,and pilot project demonstration,to evaluate the area's viability for the deep geological storage of gas and liquid waste.We studied the tectonic setting,petrological features,and sedimentary characteristics of the favorable strata and predicted favorable areas based on sequence stratigraphy theory.The lithology predominantly consists of feldspathic graywacke,with a fine grain size and mostly fine-to-medium-grained sandstone.The distribution of thick-grained sandstone and fine-grained sediment was identified by dividing the sequence,and a favorable reservoir-cap assemblage configuration was formed.It's concluded that the Lower Triassic Liujiagou Formation exhibits suitable characteristics for the deep geological storage of carbon dioxide and saline water.This study demonstrates the importance of basic theory in guiding practical applications and provides a reference for the scientific selection of favorable areas for deep basin storage. 展开更多
关键词 Ordos Basin Liujiagou Formation Sedimentary facies Sequence stratigraphy geological storage
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Modularized and Parametric Modeling Technology for Finite Element Simulations of Underground Engineering under Complicated Geological Conditions
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作者 Jiaqi Wu Li Zhuo +4 位作者 Jianliang Pei Yao Li Hongqiang Xie Jiaming Wu Huaizhong Liu 《Computer Modeling in Engineering & Sciences》 SCIE EI 2024年第7期621-645,共25页
The surrounding geological conditions and supporting structures of underground engineering are often updated during construction,and these updates require repeated numerical modeling.To improve the numerical modeling ... The surrounding geological conditions and supporting structures of underground engineering are often updated during construction,and these updates require repeated numerical modeling.To improve the numerical modeling efficiency of underground engineering,a modularized and parametric modeling cloud server is developed by using Python codes.The basic framework of the cloud server is as follows:input the modeling parameters into the web platform,implement Rhino software and FLAC3D software to model and run simulations in the cloud server,and return the simulation results to the web platform.The modeling program can automatically generate instructions that can run the modeling process in Rhino based on the input modeling parameters.The main modules of the modeling program include modeling the 3D geological structures,the underground engineering structures,and the supporting structures as well as meshing the geometric models.In particular,various cross-sections of underground caverns are crafted as parametricmodules in themodeling program.Themodularized and parametric modeling program is used for a finite element simulation of the underground powerhouse of the Shuangjiangkou Hydropower Station.This complicatedmodel is rapidly generated for the simulation,and the simulation results are reasonable.Thus,this modularized and parametric modeling program is applicable for three-dimensional finite element simulations and analyses. 展开更多
关键词 Underground engineering modularized and parametric modeling finite element method complex geological structure cloud modeling
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