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Spatiotemporal mapping of(ultra‐)mafic magmatic mine areas:Implications of economic and political realities in China
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作者 Heling Li Liang Tang +3 位作者 Tim T.Werner Zhengmeng Hou Fan Meng Jingjing Li 《Deep Underground Science and Engineering》 2024年第1期91-102,共12页
The spatiotemporal extension/expansion of mine areas is affected by multiple factors.So far,very little has been done to examine the interaction between mine areas and political or economic realities.The(ultra‐)mafic... The spatiotemporal extension/expansion of mine areas is affected by multiple factors.So far,very little has been done to examine the interaction between mine areas and political or economic realities.The(ultra‐)mafic magmatic mines in China played a specific role in supporting national development and providing an ideal research subject for monitoring their interrelationship.In this study,remote sensing and mining‐related GIS data were used to identify and analyze 1233(ultra‐)mafic magmatic mine area polygons in China,which covered approximately 322.96 km2 of land and included a V–Ti–Fe mine,a copper–nickel mine,a chromite mine,an asbestos mine,and a diamond mine.It was found that(1)the areal expansion of mines is significantly related to the mine types,perimeter,topography,and population density.(2)The mine area variation also reflects market and policy realities.The temporal expansion of the mine area from 2010 to 2020 followed an S‐shaped pattern(with the turning point occurring in 2014),closely related to iron overcapacity and tightened mining policies.(3)The complexity(D)of the mine area may reflect mine design and excavation practices.To be specific,lower D indicates early‐stage or artisanal/small‐scale mining,whereas higher D represents large‐scale mining.This study demonstrates that the detailed mapping of mine land can serve as an indicator to implement miningrelated market and policy changes.The(ultra‐)mafic mines area data set can be accessed at https://zenodo.org/record/7636616#.Y-p0uXaZOa0. 展开更多
关键词 complexity mine area mining and socioeconomic interaction spatiotemporal distribution (ultra‐)mafic magmatic mine
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Hydrogeochemical Characterization of Groundwater from Fissured Aquifers in the Angovia Mine Operating Permit Area (Central-West Côte d’Ivoire)
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作者 Kouadio Michel Yao Tanina Drissa Soro +3 位作者 Tanoh Jean Jacques Koua Akaie Jean Fabrice Tchakray Yao Emile Desmond Konan Brou Dibi 《Journal of Water Resource and Protection》 CAS 2024年第1期83-101,共19页
The main objective of this study is to determine the hydrogeochemical specificities of the groundwater of the Angovia mine operating permit, located in the Yaouré mountains in the center-west of Côte d’Ivoi... The main objective of this study is to determine the hydrogeochemical specificities of the groundwater of the Angovia mine operating permit, located in the Yaouré mountains in the center-west of Côte d’Ivoire. To do so, descriptive and multivariate statistical analysis methods with the SOM (Self Organizing Maps) algorithm were applied to the physicochemical parameters of 17 boreholes using the calcite (ISC) and dolomite (ISD) saturation indices. The results obtained have shown that the groundwater in the Angovia mine operating permit area has an average temperature of 27.52°C (long rainy season) and 27.87&degC (long dry season) and has an average pH of 7.09 ± 0.35 during the main rainy season and 7.32 ± 0.35 during the main dry season. They are mineralized with an average electrical conductivity of 505.98 ± 302.85 μS/cm during the long rainy season and with 450.33 ± 233.74 μS/cm as average during the long dry season. The main phenomena at the origin of groundwater mineralization are water residence time, oxidation-reduction and surface inflow. The study of the relative age of the water shows that the groundwater in the Angovia mine operating permit area is mainly undersaturated with respect to calcite and dolomite. They are therefore very old in the aquifer with a slow circulation speed during the long rainy season and the long dry season. 展开更多
关键词 HYDROGEOCHEMISTRY mineRALIZATION Fissure Aquifers Operating Permits The Angovia mine
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Ecological risk assessment and early warning of heavy metal cumulation in the soils near the Luanchuan molybdenum polymetallic mine concentration area,Henan Province,central China 被引量:13
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作者 Zhen-yu Chen Yuan-yi Zhao +3 位作者 Dan-li Chen Hai-tao Huang Yu Zhao Yu-jing Wu 《China Geology》 CAS CSCD 2023年第1期15-26,共12页
The Luanchuan molybdenum polymetallic mine concentration area is rich in mineral resources and has a long history of mining.The environmental impact of long-term mining activities cannot be ignored.It is of great sign... The Luanchuan molybdenum polymetallic mine concentration area is rich in mineral resources and has a long history of mining.The environmental impact of long-term mining activities cannot be ignored.It is of great significance to study the ecological risk and the accumulation trends of heavy metals in the soil of mining areas for scientific prevention and control of heavy metal pollution.Taking the Taowanbeigou River Basin in the mine concentration area as the research object,the ecological pollution risk and cumulative effect of heavy metals in the soil of the basin were studied by using the comprehensive pollution index method,potential ecological risk assessment method and geoaccumulation index method.On this basis,the cumulative exceeding years of specific heavy metals were predicted by using the early warning model.The comprehensive potential ecological risk of heavy metals in the soil near the Luanchuan mine concentration area is moderate,and the single element Cd is the main ecological risk factor,with a contribution rate of 53.6%.The overall cumulative degrees of Cu and Pb in the soil are“none-moderate”,Zn and Cd are moderate,Mo has reached an extremely strong cumulative level,Hg,As and Cr risks are not obvious,and the overall cumulative risks order is Mo>Cd>Zn>Cu>Pb>Hg.According to the current accumulation rate and taking the risk screening values for soil contamination of agricultural land as the reference standard,the locations over standard rates of Cu,Zn and Cd will exceed 78%in 90years,and the over standard rate of Pb will reach approximately 57%in 200 years.The cumulative exceeding standard periods of As,Cr and Hg are generally long,which basically indicates that these elements do not pose a significant potential threat to the ecological environment.Mining activities will accelerate the accumulation of heavy metals in soil.With the continuous development of mining activities,the potential pollution risk of heavy metals in the soil of mining areas will also increase. 展开更多
关键词 Soil Heavy metals Mining impact Cumulative effect Potential ecological risk Cumulation early warning Luanchuan mine concentration area Environmental geological survey engineering
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Stability control measures for roof cutting and NPR supporting of mining roadways in fault areas of kilometre-deep coal mine 被引量:1
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作者 SUN Xiao-ming WANG Jian +5 位作者 ZHANG Yong ZHAO Wen-chao GUO Zhi-biao HE Man-chao CHEN Feng MIAO Cheng-yu 《Journal of Mountain Science》 SCIE CSCD 2023年第10期3051-3065,共15页
The study focuses on the stability control measures for mining roadways in fault zones of deep mines,using Daqiang Coal Mine as a case study.The control system under consideration,referred to as"pre-splitting cut... The study focuses on the stability control measures for mining roadways in fault zones of deep mines,using Daqiang Coal Mine as a case study.The control system under consideration,referred to as"pre-splitting cutting roof+NPR anchor cable"(PSCR-NPR),is subjected to scrutiny through theoretical analysis,numerical modelling,and field trials.Furthermore,a comprehensive analysis is undertaken to evaluate the stability control mechanism of this particular technology.The study provides evidence that the utilization of deep-hole directional energy-concentrated blasting facilitates the attainment of directional roof cutting in roadways.The aforementioned procedure leads to the formation of a uniform structural surface on the roof of the roadway and causes modifications in the surrounding geological formation.The examination of the lateral abutment pressure and shear stress distribution,both prior to and subsequent to roof cutting,indicates that the implementation of pre-splitting techniques leads to a noteworthy reduction in pressure.The proposition of incorporating the safety factor Q for roof cutting height is suggested as a method to augment comprehension of the pressure relief phenomenon in the field of engineering.The analysis of numerical simulation has indicated that the optimal pressure relief effect of a mining roadway in a fault area is attained when the value of Q is 1.8.The NPR anchor cable exhibits noteworthy characteristics,including a high level of prestress,continuous resistance,and substantial deformation.After the excavation of the roadway,a notable reduction in radial stress occurs,leading to the reinstatement of the three-phase stress state in the surrounding rock.This restoration is attributed to the substantial prestress exerted on the radial stress.The termination point of the NPR anchor cable is strategically positioned within a stable rock formation,allowing for the utilization of the mechanical characteristics of the deep stable rock mass.This positioning serves to improve the load-bearing capacity of the surrounding rock.The mining roadway within the fault region of Daqiang Coal Mine is outfitted with the PSCR-NPR technology.The drop in shear stress experienced by the rock surrounding the roadway is estimated to be around 30%,whilst the low-stress region of the mining roadway extends by a factor of approximately 5.5.The magnitude of surface displacement convergence experiences a decrease of approximately 45%-50%.The study’s findings provide useful insights regarding the stable of mining roadway in characterized by fault zones. 展开更多
关键词 Kilometre-deep mine FAULT Mining roadway Pre-splitting cutting roof High pre-stress NPR anchor cable
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Instability identification on large scale underground mined-out area in the metal mine based on the improved FRBFNN 被引量:4
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作者 Luo Zhouquan Zuo Hongyan +1 位作者 Jia Nan Wang Yiwei 《International Journal of Mining Science and Technology》 SCIE EI 2013年第6期821-826,共6页
To identify the instability on large scale underground mined-out area in the metal mine effectively,the parameters of radial basis function were determined through clustering method and the improved fuzzy radial basis... To identify the instability on large scale underground mined-out area in the metal mine effectively,the parameters of radial basis function were determined through clustering method and the improved fuzzy radial basis function neural network(FRBFNN)model of instability identification model about large scale underground mined-out area in the metal mine was built.The improved FRBFNN model was trained and tested.The results show that the improved FRBFNN model has high training accuracy and generalization ability.Parameters such as pillar area ratio,filling level and the value of rock quality designation have strong influence on instability of large scale underground mined-out area.Correctness of analysis about the improved FRBFNN model was proved by the practical application results about instability discrimination of surrounding rock in large-scale underground mined-out area of a metal mine in south China. 展开更多
关键词 Metal mine Fuzzy theory mined-out area RBF neural network DISCRIMINATION
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Numerical analysis of stability for mined-out area in multi-field coupling 被引量:5
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作者 罗周全 谢承煜 +3 位作者 周吉明 贾楠 刘晓明 徐海 《Journal of Central South University》 SCIE EI CAS CSCD 2015年第2期669-675,共7页
There were differences between real boundary and blast hole controlling boundary of irregular mined-out area in underground metal mines. There were errors in numerical analysis of stability for goaf, if it was analyze... There were differences between real boundary and blast hole controlling boundary of irregular mined-out area in underground metal mines. There were errors in numerical analysis of stability for goaf, if it was analyzed as regular 3D mined-out area and the influence of coupling stress-seepage-disturbance was not considered adequately. Taking a lead zinc mine as the background, the model was built by the coupling of Surpac and Midas-Gts based on the goaf model precisely measured by CMS.According to seepage stress fundamental equations based on the equivalent continuum mechanical and the theory about equivalent load of dynamic disturbance in deep-hole blasting, the stability of mined-out area under multi-field coupling of stress-seepage-dynamic disturbance was numerically analyzed. The results show that it is more consistent between the numerical analysis model based on the real model of irregular 3D shape goaf and the real situation, which could faithfully reappear the change rule of stress–strain about the surrounding rock under synthetic action of blasting dynamic loading and the seepage pressure. The mined-out area multi-field coupling formed by blasting excavation is stable. Based on combination of the advantages of the CMS,Surpac and Midas-Gts, and fully consideration of the effects of multi-field coupling, the accurate and effective way could be provided for numerical analysis of stability for mined-out area. 展开更多
关键词 mined-out area measured actually multi-field coupling stress-seepage-disturbance stability for mined-out area
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Quantitative analysis of biotechnical reinforcement for a steep slope consisting of composite coal-gangue-soil medium adjacent to a mined-out area 被引量:3
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作者 Xingping Lai Mowen Xie +1 位作者 Fenhua Ren Meifeng Cai 《Journal of University of Science and Technology Beijing》 CSCD 2005年第6期489-494,共6页
The engineering and geological characteristics of a steep slope consisting of coal gangue, rock and soil medium in Huating coal mine have been comprehensively investigated. Owing to humid weather, heavy rainfall, vege... The engineering and geological characteristics of a steep slope consisting of coal gangue, rock and soil medium in Huating coal mine have been comprehensively investigated. Owing to humid weather, heavy rainfall, vegetation and porous characteristics of the soil and rock mass, the steep slope will be destabilized and induce mud-rock flow or derive hazard easily. Firstly, based on the classical slope reinforcement theory, some regularity between the shear and displacement in the destabilized zone of the slope with or without root strength contribution is presented. Then, based on the experimental and statistical analysis of root strength, hydrological characteristics and stability status, etc., some possible biotechnical techniques for reinforcement of the steep slope have been suggested. These methods are important for quantitative analysis of destabilization of the slope and design of the biotechnical reinforcement. 展开更多
关键词 mined-out area coal-gangue-soil composite medium steep slope root-soil effect biotechnical reinforcement
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Time function of surface subsidence based on Harris model in mined-out area 被引量:7
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作者 Liu Xinrong Wang Junbao +2 位作者 Guo Jianqiang Yuan Hong Li Peng 《International Journal of Mining Science and Technology》 SCIE EI 2013年第2期251-254,共4页
The surface subsidence is a common environmental hazard in mined-out area. Based on careful analysis of the regularity of surface subsidence in mined-out area, we proposed a new time function based on Harris curve mod... The surface subsidence is a common environmental hazard in mined-out area. Based on careful analysis of the regularity of surface subsidence in mined-out area, we proposed a new time function based on Harris curve model in consideration of the shortage of current surface subsidence time functions. By analyzing the characteristics of the new time function, we found that it could meet the dynamic process, the velocity change process and the acceleration change process during surface subsidence. Then its rationality had been verified through project cases. The results show that the proposed time function model can give a good reflection of the regularity of surface subsidence in mined-out area and can accurately predict surface subsidence. And the prediction data of the model are a little greater than measured data on condition of proper measured data quantity, which is safety in the engineering. This model provides a new method for the analysis of surface subsidence in mined-out area and reference for future prediction, and it is valuable to engineering application. 展开更多
关键词 mined-out area Surface subsidence Time function Harris model Prediction
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Ecological Restoration Technology and Carbon Reduction Paths of Abandoned Mines in Zoige Alpine Grassland Area
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作者 Jiaolong YE Zhengqiang XU +1 位作者 Hongmei ZHONG Hong YUAN 《Meteorological and Environmental Research》 CAS 2023年第5期48-53,共6页
At first,the ecological restoration technology of abandoned mines is summarized,and the paths and models of mine ecological restoration in Zoige grassland area under the background of carbon neutrality are analyzed.Mo... At first,the ecological restoration technology of abandoned mines is summarized,and the paths and models of mine ecological restoration in Zoige grassland area under the background of carbon neutrality are analyzed.Moreover,the problems and deficiencies in the current research on mine ecological restoration in Zoige grassland area are initially identified,and the future research trend is prospected to provide a reference for the path of carbon reduction by mine ecological restoration in Zoige grassland area and other alpine grassland areas in the future. 展开更多
关键词 Carbon neutrality Alpine grassland mining area Ecological restoration
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Instability mechanism of mining roadway passing through fault at different angles in kilometre-deep mine and control measures of roof cutting and NPR cables 被引量:2
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作者 SUN Xiaoming WANG Jian +6 位作者 ZHAO Wenchao MING Jiang ZHANG Yong LI Zhihu MIAO Chengyu GUO Zhibiao HE Manchao 《Journal of Mountain Science》 SCIE CSCD 2024年第1期236-251,共16页
The angle α between the fault strike and the axial direction of the roadway produces different damage characteristics. In this paper, the research methodology includes theoretical analyses, numerical simulations and ... The angle α between the fault strike and the axial direction of the roadway produces different damage characteristics. In this paper, the research methodology includes theoretical analyses, numerical simulations and field experiments in the context of the Daqiang coal mine located in Shenyang, China. The stability control countermeasure of "pre-splitting cutting roof + NPR anchor cable"(PSCR-NPR) is simultaneously proposed. According to the different deformation characteristics of the roadway, the faults are innovatively classified into three types, with α of type I being 0°-30°, α of type II being 30°-60°, and α of type III being 60°-90°. The full-cycle stress evolution paths during mining roadway traverses across different types of faults are investigated by numerical simulation. Different pinch angles α lead to high stress concentration areas at different locations in the surrounding rock. The non-uniform stress field formed in the shallow surrounding rock is an important reason for the instability of the roadway. The pre-cracked cut top shifted the high stress region to the deep rock mass and formed a low stress region in the shallow rock mass. The high prestressing NPR anchor cable transforms the non-uniform stress field of the shallow surrounding rock into a uniform stress field. PSCR-NPR is applied in the fault-through roadway of Daqiang mine. The low stress area of the surrounding rock was enlarged by 3-7 times, and the cumulative convergence was reduced by 45%-50%. It provides a reference for the stability control of the deep fault-through mining roadway. 展开更多
关键词 Kilometre-deep mine Fault Mining roadway Failure mechanism Pre-splitting cutting roof High pre-stress NPR anchor cable
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Ecological-Based Mining:A Coal-Water-Thermal Collaborative Paradigm in Ecologically Fragile Areas in Western China 被引量:2
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作者 Xiaoxiu Liu Yifan Zeng +3 位作者 Qiang Wu Shihao Meng Jiyue Liang Zhuping Hou 《Engineering》 SCIE EI CAS CSCD 2024年第7期209-222,共14页
A substantial reduction in groundwater level,exacerbated by coal mining activities,is intensifying water scarcity in western China’s ecologically fragile coal mining areas.China’s national strategic goal of achievin... A substantial reduction in groundwater level,exacerbated by coal mining activities,is intensifying water scarcity in western China’s ecologically fragile coal mining areas.China’s national strategic goal of achieving a carbon peak and carbon neutrality has made eco-friendly mining that prioritizes the protection and efficient use of water resources essential.Based on the resource characteristics of mine water and heat hazards,an intensive coal-water-thermal collaborative co-mining paradigm for the duration of the mining process is proposed.An integrated system for the production,supply,and storage of mining companion resources is achieved through technologies such as roof water inrush prevention and control,hydrothermal quality improvement,and deep-injection geological storage.An active preventive and control system achieved by adjusting the mining technology and a passive system centered on multiobjective drainage and grouting treatment are suggested,in accordance with the original geological characteristics and dynamic process of water inrush.By implementing advanced multi-objective drainage,specifically designed to address the“skylight-type”water inrush mode in the Yulin mining area of Shaanxi Province,a substantial reduction of 50%in water drillings and inflow was achieved,leading to stabilized water conditions that effectively ensure subsequent safe coal mining.An integrated-energy complementary model that incorporates the clean production concept of heat utilization is also proposed.The findings indicate a potential saving of 8419 t of standard coal by using water and air heat as an alternative heating source for the Xiaojihan coalmine,resulting in an impressive energy conservation of 50.2%and a notable 24.2%reduction in carbon emissions.The ultra-deep sustained water injection of 100 m^(3)·h^(-1)in a single well would not rupture the formation or cause water leakage,and 7.87×10^(5)t of mine water could be effectively stored in the Liujiagou Formation,presenting a viable method for mine-water management in the Ordos Basin and providing insights for green and low-carbon mining. 展开更多
关键词 Dual carbon targets Coal-water-thermal co-mining Ecologically fragile areas mine-water control Resource utilization
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Numerical simulation for influence of excavation and blasting vibration on stability of mined-out area 被引量:11
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作者 徐国元 闫长斌 《Journal of Central South University of Technology》 EI 2006年第5期577-583,共7页
Dynamic analysis steps and general flow of fast lagrangian analysis of continua in 3 dimensions(FLAC3D) were discussed. Numerical simulation for influence of excavation and blasting vibration on stability of mined-out... Dynamic analysis steps and general flow of fast lagrangian analysis of continua in 3 dimensions(FLAC3D) were discussed. Numerical simulation for influence of excavation and blasting vibration on stability of mined-out area was carried out with FLAC3D. The whole analytical process was divided into two steps, including the static analysis and the dynamic analysis which were used to simulate the influence of excavation process and blasting vibration respectively. The results show that the shape of right upper boundary is extremely irregular after excavation, and stress concentration occurs at many places and higher tensile stress appears. The maximum tensile stress is higher than the tensile strength of rock mass, and surrounding rock of right roof will be damaged with tension fracture. The maximum displacement of surrounding rock is 4.75 mm after excavation. However, the maximum displacement increases to 5.47 mm after the blasting dynamic load is applied. And the covering area of plastic zones expands obviously, especially at the foot of right upper slope. The analytical results are in basic accordance with the observed results on the whole. Damage and disturbance on surrounding rock to some degree are caused by excavation, while blasting dynamic load increases the possibility of occurrence of dynamic instability and destruction further. So the effective supporting and vibration reducing measures should be taken during mining. 展开更多
关键词 mined-out area excavation process blasting vibration STABILITY numerical simulation FLAC3D
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Correlation of periodontal inflamed surface area with glycated hemoglobin,interleukin-6 and lipoprotein(a)in type 2 diabetes with retinopathy 被引量:3
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作者 Nusreen Jamal Thazhe Poyil Rosamma Joseph Vadakkekuttical Chandni Radhakrishnan 《World Journal of Diabetes》 SCIE 2024年第4期686-696,共11页
BACKGROUND The two-way relationship between periodontitis and type 2 diabetes mellitus(T2DM)is well established.Prolonged hyperglycemia contributes to increased periodontal destruction and severe periodontitis,accentu... BACKGROUND The two-way relationship between periodontitis and type 2 diabetes mellitus(T2DM)is well established.Prolonged hyperglycemia contributes to increased periodontal destruction and severe periodontitis,accentuating diabetic complications.An inflammatory link exists between diabetic retinopathy(DR)and periodontitis,but the studies regarding this association and the role of lipoprotein(a)[Lp(a)]and interleukin-6(IL-6)in these conditions are scarce in the literature.AIM To determine the correlation of periodontal inflamed surface area(PISA)with glycated Hb(HbA1c),serum IL-6 and Lp(a)in T2DM subjects with retinopathy.METHODS This cross-sectional study comprised 40 T2DM subjects with DR and 40 T2DM subjects without DR.All subjects were assessed for periodontal parameters[bleeding on probing(BOP),probing pocket depth,clinical attachment loss(CAL),oral hygiene index-simplified,plaque index(PI)and PISA],and systemic parameters[HbA1c,fasting plasma glucose and postprandial plasma glucose,fasting lipid profile,serum IL-6 and serum Lp(a)].RESULTS The proportion of periodontitis in T2DM with and without DR was 47.5%and 27.5%respectively.Severity of periodontitis,CAL,PISA,IL-6 and Lp(a)were higher in T2DM with DR group compared to T2DM without DR group.Significant difference was observed in the mean percentage of sites with BOP between T2DM with DR(69%)and T2DM without DR(41%),but there was no significant difference in PI(P>0.05).HbA1c was positively correlated with CAL(r=0.351,P=0.001),and PISA(r=0.393,P≤0.001)in study subjects.A positive correlation was found between PISA and IL-6(r=0.651,P<0.0001);PISA and Lp(a)(r=0.59,P<0.001);CAL and IL-6(r=0.527,P<0.0001)and CAL and Lp(a)(r=0.631,P<0.001)among study subjects.CONCLUSION Despite both groups having poor glycemic control and comparable plaque scores,the periodontal parameters were higher in DR as compared to T2DM without DR.Since a bidirectional link exists between periodontitis and DM,the presence of DR may have contributed to the severity of periodontal destruction and periodontitis may have influenced the progression of DR. 展开更多
关键词 Type 2 diabetes mellitus PERIODONTITIS Periodontal inflamed surface area Glycated Hb Diabetic retinopathy
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Differences between total amount of heavy metals and their occurrence form contents in the wastelands of a molybdenum mine area
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作者 Ping Shi Jing Huang +2 位作者 Zecan Wu Aoshuang Chen Guangxin Zhang 《International Journal of Coal Science & Technology》 EI CAS CSCD 2023年第2期210-217,共8页
In a single sample plot,the total amount of heavy metals in the soil could not necessarily reflect the contents of their effective states.This must be considered when attempting to determine the degree of soil heavy-m... In a single sample plot,the total amount of heavy metals in the soil could not necessarily reflect the contents of their effective states.This must be considered when attempting to determine the degree of soil heavy-metal pollution in an area.In the present study,the soil around the molybdenum mining area in Huludao,China,was surveyed and sampled to evaluate soil heavy-metal pollution using the Nemerow multifactor pollution index method.The Tessier continuous extraction method was used to analyze the distribution of heavy-metal forms'and their content changes in the soil of this area.Thus,the bioactivity of heavy metals in the soil,the absorption of heavy metals by plants,and the distribution of heavy metals in plants were explored to provide data supporting the use of phytoremediation technology to treat the heavy-metal pollution in the molybdenum mining area and develop ecological restoration strategies for the area's wastelands.The pollution index results indicate that heavy-metal pollution in the soil around the tailings pond is severe,mainly due to Pb and Zn heavy metals.Heavy-metal pollution in the surrounding land is mainly due to Cd and Zn.Content analysis of the heavy-metal forms/states in soils shows that exchangeable forms,which are most effective and toxic to plants,of the following metals are highest in the following areas:Cd,Cu,and Zn in the mountains around the stope;Zn,Mo,and Cu in the cultivated land around the dump;and Cd,Zn,and Mo in the cultivated land around the tailings pond.The pollution index analysis provides a basic overview of soil heavy-metal pollution across the entire mining area.However,content analysis of heavy-metal forms/states better reflects the relationship between the availability of heavy metals in the soil and the effectiveness of plants.Thus,the latter analysis can help ensure that phytoremediation strategies are adequately targeted,science-based,and effective. 展开更多
关键词 Molybdenum mining WASTELAND Soil pollution Heavy metal BIOAVAILABILITY PHYTOREMEDIATION
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Earthquake focal mechanisms and stress field in Sichuan-Yunnan area determined using P wave polarity and short period P and S waveform data 被引量:1
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作者 陈天长 郑斯华 ZHENG Si-hua 《Acta Seismologica Sinica(English Edition)》 CSCD 2001年第4期466-470,共5页
关键词 Sichuan-Yunnan area focal mechanism stress field
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Research on the Relationship Between Environmental and Economic Coupling Systems in Bohai Bay Area Based on a Vector Autoregression(VAR)Model 被引量:1
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作者 CAO Huimin WANG Ping +2 位作者 ZHANG Surong XU Dongpo TIAN Weijun 《Journal of Ocean University of China》 CAS CSCD 2024年第2期557-566,共10页
This study analyzed the impact of land-based contaminants and tertiary industrial structure on economic development in the selected Bohai Bay area,China.Based on panel data spanning 2011-2020,a vector autoregressive(V... This study analyzed the impact of land-based contaminants and tertiary industrial structure on economic development in the selected Bohai Bay area,China.Based on panel data spanning 2011-2020,a vector autoregressive(VAR)model is used to analyze and forecast the short-run and long-run relationships between three industrial structures,pollutant discharge,and economic development.The results showed that the environmental index had a long-term cointegration relationship with the industrial structure economic index.Per capital chemical oxygen demand(PCOD)and per capita ammonia nitrogen(PNH_(3)N)had a positive impact on delta per capita GDP(dPGDP),while per capita solid waste(PSW),the secondary industry rate(SIR)and delta tertiary industry(dTIR)had a negative impact on dPGDP.The VAR model under this coupling system had stability and credibility.The impulse response results showed that the short-term effect of the coupling system on dPGDP was basically consistent with the Granger causality test results.In addition,variance decomposition was used in this study to predict the long-term impact of the coupling system in the next ten periods(i.e.,ten years).It was found that dTIR had a great impact on dPGDP,with a contribution rate as high as 74.35%in the tenth period,followed by the contribution rate of PCOD up to 3.94%,while the long-term contribution rates of PSW,SIR and PNH3N were all less than 1%.The results show that the government should support the development of the tertiary industry to maintain the vitality of economic development and prevent environmental deterioration. 展开更多
关键词 Bohai Bay area environmental pollution industrial structure cointegration theory VAR model impulse response
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Seismic response of a mid-story isolated structure considering SSI in mountainous areas under long-period earthquakes 被引量:1
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作者 Wan Feng Qin Shengwu +7 位作者 Liu Dewen Zhao Tiange Zheng Yanping Shan Hang Li Zhiang Peng Fusong Xu Jingran Lei Min 《Earthquake Engineering and Engineering Vibration》 SCIE EI CSCD 2024年第1期151-161,共11页
At present,there is not much research on mid-story isolated structures in mountainous areas.In this study,a model of a mid-story isolated structure considering soil-structure interaction(SSI)in mountainous areas is es... At present,there is not much research on mid-story isolated structures in mountainous areas.In this study,a model of a mid-story isolated structure considering soil-structure interaction(SSI)in mountainous areas is established along with a model that does not consider SSI.Eight long-period earthquake waves and two ordinary earthquake waves are selected as inputs for the dynamic time history analysis of the structure.The results show that the seismic response of a mid-story isolated structure considering SSI in mountainous areas can be amplified when compared with a structure that does not consider SSI.The structure response under long-period earthquakes is larger than that of ordinary earthquakes.The structure response under far-field harmonic-like earthquakes is larger than that of near-fault pulse-type earthquakes.The structure response under near-fault pulse-type earthquakes is larger than that of far-field non-harmonic earthquakes.When subjected to long-period earthquakes,the displacement of the isolated bearings exceeded the limit value,which led to instability and overturning of the structure.The structure with dampers in the isolated story could adequately control the nonlinear response of the structure,effectively reduce the displacement of the isolated bearings,and provide a convenient,efficient and economic method not only for new construction but also to retrofit existing structures. 展开更多
关键词 SSI in mountainous areas long-period earthquakes mid-story isolated structure structural dynamic analysis
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Collagen proportionate area of liver tissue determined by digital image analysis in patients with HBV-related decompensated cirrhosis 被引量:1
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作者 Shi-Bin Xie, Chao Ma, Chao-Shuang Lin,Ying Zhang, Jian-Yun Zhu and Wei-Min Ke Department of Infectious Disease, Third Affiliated Hospital, Sun Yat-Sen University, Guangzhou 510630, China 《Hepatobiliary & Pancreatic Diseases International》 SCIE CAS 2011年第5期497-501,共5页
BACKGROUND: The accurate assessment of the degree of hepatic fibrosis plays a critical role in guiding the diagnosis, treatment and prognostic assessment of chronic liver diseases. Liver biopsy is currently the most r... BACKGROUND: The accurate assessment of the degree of hepatic fibrosis plays a critical role in guiding the diagnosis, treatment and prognostic assessment of chronic liver diseases. Liver biopsy is currently the most reliable method to evaluate the severity of hepatic fibrosis. However, liver biopsy is an invasive procedure associated with morbidity and mortality, and has several limitations in patients with decompensated cirrhosis. There is no report on the collagen proportionate area (CPA) of liver tissue in the decompensated stage of cirrhosis. This study aimed to determine the CPA of resected liver tissue samples from patients with HBV-related decompensated cirrhosis using digital image analysis, and to analyze the relationship between the CPA and liver functional reserve. METHODS: Fifty-three resected liver tissue samples from liver transplant patients with chronic hepatitis B-induced decompensated cirrhosis were stained with Masson’s trichrome, and the CPA in these samples was quantitatively determined using digital image analysis. The values of relevant liver function just before liver transplantation, the CPA in liver tissue, and their correlation were analyzed. RESULTS: The mean CPA at the decompensated stage of cirrhosis was 35.93±14.42% (11.24%-63.41%). The correlation coefficients of the CPA with a model for end-stage liver disease score, serum total bilirubin and international standard ratio of prothrombin B were 0.553, 0.519 and 0.533, respectively (P<0.001). With increasing CPA values, the three indices reflecting liver functional reserve also changed significantly.CONCLUSIONS: The degree of fibrosis may be correlated with the functional reserve. With the advancement of fibrosis, the liver functional reserve is attenuated accordingly. 展开更多
关键词 collagen proportionate area digital image analysis decompensated cirrhosis chronic hepatitis B
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Residual subsidence time series model in mountain area caused by underground mining based on GNSS online monitoring
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作者 Xugang Lian Lifan Shi +2 位作者 Weiyu Kong Yu Han Haodi Fan 《International Journal of Coal Science & Technology》 EI CAS CSCD 2024年第2期173-186,共14页
The residual subsidence caused by underground mining in mountain area has a long subsidence duration time and great potential harm,which seriously threatens the safety of people's production and life in the mining... The residual subsidence caused by underground mining in mountain area has a long subsidence duration time and great potential harm,which seriously threatens the safety of people's production and life in the mining area.Therefore,it is necessary to use appropriate monitoring methods and mathematical models to effectively monitor and predict the residual subsidence caused by underground mining.Compared with traditional level survey and InSAR(Interferometric Synthetic Aperture Radar)technology,GNSS(Global Navigation Satellite System)online monitoring technology has the advantages of long-term monitoring,high precision and more flexible monitoring methods.The empirical equation method of residual subsidence in mining subsidence is effectively combined with the rock creep equation,which can not only describe the residual subsidence process from the mechanism,but also predict the residual subsidence.Therefore,based on GNSS online monitoring technology,combined with the mining subsidence model of mountain area and adding the correlation coefficient of the compaction degree of caving broken rock and the Kelvin model of rock mechanics,this paper constructs the residual subsidence time series model of arbitrary point on the ground in mountain area.Through the example,the predicted results of the model in the inversion parameter phase and the dynamic prediction phase are compared with the measured data sequence.The results show that the model can carry out effective numerical calculation according to the GNSS monitoring data of any point on the ground,and the model prediction effect is good,which provides a new method for the prediction of residual subsidence in mountain mining. 展开更多
关键词 Underground mining in mountain area Residual subsidence GNSS online monitoring Mathematical model Subsidence prediction
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Integrated Structure and Mineralization Study Using Aero-Magnetic, Aero-Spectrometric and Remote Sensing Data at Esh El-Mallaha Area, Eastern Desert, Egypt
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作者 Ahmed A. Elhusseiny 《Geomaterials》 CAS 2023年第1期1-22,共22页
The main scope of this research is to detect geologic structure trends affecting the study area, determine uranium anomalous areas and define alteration zones. Airborne magnetic data were used to detect the geologic s... The main scope of this research is to detect geologic structure trends affecting the study area, determine uranium anomalous areas and define alteration zones. Airborne magnetic data were used to detect the geologic structure trends affecting the study area through applying edge detectors such as total horizontal derivative, analytic signal and tilt derivative. The radio-spectrometry data and Landsat image data were used in determining the uranium anomalous areas and alteration zones. The integration between geology, magnetic and Landsat image was applied through constructing lineaments density map for the three data sets resulting in the leading of NW-SE trend all over the area. This integration makes clear that the basement (Red Sea hills), Esh El-mallaha range and G. Zeit are limiting two large basins (West Mallaha and Zeit). In addition, the main areas of uranium enrichment (Duwi formation at Esh El-Mallaha range) are found to be well related to alteration zones. 展开更多
关键词 Structure Trends Uranium Zones Alteration Zones Magnetic Analysis Landsat-8 OLI Image Esh El-Mallaha area
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