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Dynamic response characteristics of muddy sandstone in pumped storage mine under action of high-stress dynamic disturbance
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作者 LIANG Bin WANG Dong +3 位作者 LUAN Heng-jie DONG Ling LIU Jian-kang WANG Chang-sheng 《Journal of Central South University》 SCIE EI CAS CSCD 2024年第8期2736-2747,共12页
During the construction and operation of the abandoned mine pumped storage power station,the underground space surrounding rock body faces the complex stress environment under the action of mining disturbance,frequent... During the construction and operation of the abandoned mine pumped storage power station,the underground space surrounding rock body faces the complex stress environment under the action of mining disturbance,frequent pumping,water storage and other dynamic disturbances.The stability of the abandoned mine surrounding rock body is the basis for guaranteeing the safety and effectiveness of water storage in the underground space of the abandoned mine.By considering the two main factors of different stress levels and disturbance amplitudes,the mechanical properties,damage characteristics and acoustic emission characteristics of the abandoned mine perimeter rock body under dynamic disturbance were investigated using a creep-disturbed dynamic impact loading system.The experimental results show that:1)The stress level is considered to be the major contributing factor of the failure of muddy sandstone,followed by the amplitude of the disturbances;2)The time required for the destruction of muddy sandstone decreases with the increase of amplitude.When the stress level is 80%,the sandstone specimens have a decreasing number of cycles as the disturbance amplitude increases.The disturbance amplitude is sequentially increased from 4 MPa to 5,6,7,and 8 MPa,the number of cycles required for specimen destruction decreases significantly by 96.71%,99.13%,99.60%,and 99.93%,respectively;3)Disturbance amplitude and stress level have a significant effect on muddy sandstone damage and damage occurs only after a certain threshold is reached.With the increase of stress level and disturbance amplitude,the macroscopic damage of muddy sandstone is mainly conical,with obvious flake spalling and poor damage integrity;4)According to the time-dependent changes in AE energy and ringing counts,the acoustic emission activity during the failure process could be divided into three phases,namely,weakening period,smooth period,and surge period,corresponding to the compaction phase,elastic rise phase and post-peak damage phase.The research results are of reference significance for the damage evolution analysis of muddy sandstone under dynamic disturbance and the safety and stability of abandoned mine perimeter rock body. 展开更多
关键词 abandoned mine pumped storage dynamic disturbance muddy sandstone acoustic emission
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Research on pumped storage and complementary energy development models for abandoned mines in China
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作者 YANG Ke LYU Xin +3 位作者 XU Chao-shui FANG Jue-jing DUAN Min-ke ZHANG Zhai-nan 《Journal of Central South University》 SCIE EI CAS CSCD 2024年第8期2860-2871,共12页
Within the framework of achieving carbon neutrality,various industries are confronted with fresh challenges.The ongoing process of downsizing coal industry operations has evolved into a new phase,with the burgeoning p... Within the framework of achieving carbon neutrality,various industries are confronted with fresh challenges.The ongoing process of downsizing coal industry operations has evolved into a new phase,with the burgeoning proliferation of abandoned mines posing a persistent issue.Addressing the challenges and opportunities presented by these abandoned mines,this paper advocates for a scientific approach centered on the advancement of pumped storage energy alongside gas-oil complementary energy.Leveraging abandoned mine tunnels to establish pumped storage power stations holds significant ecological and economic importance for repurposing these sites.This initiative not only serves as an effective means to restore the ecological balance in mining regions but also provides an environmentally friendly approach to repurposing abandoned mine tunnels,offering a blueprint for economically viable pumped storage power stations.This article delineates five crucial scientific considerations and outlines seven primary models for the utilization of abandoned mine sites,delineating a novel,comprehensive pathway for energy and power development that emphasizes multi-energy complementarity and synergistic optimization within abandoned mines. 展开更多
关键词 abandoned mines pumped storage underground reservoir energy systems carbon neutrality
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Evaluation of development potential of pumped hydroelectric storage and geothermal utilization system in abandoned coal mine
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作者 WANG Meng GUO Ping-ye +3 位作者 JIN Xin DANG Guan-jie GUO Yi-chen LI Yi 《Journal of Central South University》 SCIE EI CAS CSCD 2024年第8期2872-2890,共19页
Every year in China,a significant number of mines are closed or abandoned.The pumped hydroelectric storage(PHS)and geothermal utilization are vital means to efficiently repurpose resources in abandoned mine.In this wo... Every year in China,a significant number of mines are closed or abandoned.The pumped hydroelectric storage(PHS)and geothermal utilization are vital means to efficiently repurpose resources in abandoned mine.In this work,the development potentials of the PHS and geothermal utilization systems were evaluated.Considering the geological conditions and meteorological data available of Jiahe abandoned mine,a simple evaluation model for PHS and geothermal utilization was established.The average efficiency of the PHS system exceeds 70%and the regulatable energy of a unit volume is over 1.53 kW·h/m^(3).The PHS system achieves optimal performance when the wind/solar power ratio reaches 0.6 and 0.3 in daily and year scale,respectively.In the geothermal utilization system,the outlet temperature and heat production are significantly affected by the injection flow rate.The heat production performance is more stable at lower rate flow,and the proportion of heat production is higher in the initial stage at greater flow rate.As the operating time increases,the proportion of heat production gradually decreases.The cyclic heat storage status has obvious advantages in heat generation and cooling.Furthermore,the energy-saving and emission reduction benefits of PHS and geothermal utilization systems were calculated. 展开更多
关键词 abandoned mine underground reservoir wind/solar energy pumped hydroelectric storage GEOTHERMAL
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Feature extraction and analysis of reclaimed vegetation in ecological restoration area of abandoned mines based on hyperspectral remote sensing images
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作者 MAO Zhengjun WANG Munan +3 位作者 CHU Jiwei SUN Jiewen LIANG Wei YU Haiyong 《Journal of Arid Land》 SCIE CSCD 2024年第10期1409-1425,共17页
The vegetation growth status largely represents the ecosystem function and environmental quality.Hyperspectral remote sensing data can effectively eliminate the effects of surface spectral reflectance and atmospheric ... The vegetation growth status largely represents the ecosystem function and environmental quality.Hyperspectral remote sensing data can effectively eliminate the effects of surface spectral reflectance and atmospheric scattering and directly reflect the vegetation parameter information.In this study,the abandoned mining area in the Helan Mountains,China was taken as the study area.Based on hyperspectral remote sensing images of Zhuhai No.1 hyperspectral satellite,we used the pixel dichotomy model,which was constructed using the normalized difference vegetation index(NDVI),to estimate the vegetation coverage of the study area,and evaluated the vegetation growth status by five vegetation indices(NDVI,ratio vegetation index(RVI),photochemical vegetation index(PVI),red-green ratio index(RGI),and anthocyanin reflectance index 1(ARI1)).According to the results,the reclaimed vegetation growth status in the study area can be divided into four levels(unhealthy,low healthy,healthy,and very healthy).The overall vegetation growth status in the study area was generally at low healthy level,indicating that the vegetation growth status in the study area was not good due to short-time period restoration and harsh damaged environment such as high and steep rock slopes.Furthermore,the unhealthy areas were mainly located in Dawukougou where abandoned mines were concentrated,indicating that the original mining activities have had a large effect on vegetation ecology.After ecological restoration of abandoned mines,the vegetation coverage in the study area has increased to a certain extent,but the amplitude was not large.The situation of vegetation coverage in the northern part of the study area was worse than that in the southern part,due to abandoned mines mainly concentrating in the northern part of the Helan Mountains.The combination of hyperspectral remote sensing data and vegetation indices can comprehensively extract the characteristics of vegetation,accurately analyze the plant growth status,and provide technical support for vegetation health evaluation. 展开更多
关键词 hyperspectral remote sensing abandoned mine ecological restoration vegetation growth status vegetation index vegetation coverage
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Effects of land-use patterns on soil microbial diversity and composition in the Loess Plateau,China
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作者 ZHANG Jian GUO Xiaoqun +2 位作者 SHAN Yujie LU Xin CAO Jianjun 《Journal of Arid Land》 SCIE CSCD 2024年第3期415-430,共16页
In the Loess Plateau of China,land-use pattern is a major factor in controlling underlying biological processes.Additionally,the process of land-use pattern was accompanied by abandoned lands,potentially impacting soi... In the Loess Plateau of China,land-use pattern is a major factor in controlling underlying biological processes.Additionally,the process of land-use pattern was accompanied by abandoned lands,potentially impacting soil microbe.However,limited researches were conducted to study the impacts of land-use patterns on the diversity and community of soil microorganisms in this area.The study aimed to investigate soil microbial community diversity and composition using high-throughput deoxyribonucleic acid(DNA)sequencing under different land-use patterns(apricot tree land,apple tree land,peach tree land,corn land,and abandoned land).The results showed a substantial difference(P<0.050)in bacterial alpha-diversity and beta-diversity between abandoned land and other land-use patterns,with the exception of Shannon index.While fungal beta-diversity was not considerably impacted by land-use patterns,fungal alpha-diversity indices varied significantly.The relative abundance of Actinobacteriota(34.90%),Proteobacteria(20.65%),and Ascomycota(77.42%)varied in soils with different land-use patterns.Soil pH exerted a dominant impact on the soil bacterial communities'composition,whereas soil available phosphorus was the main factor shaping the soil fungal communities'composition.These findings suggest that variations in land-use pattern had resulted in changes to soil properties,subsequently impacting diversity and structure of microbial community in the Loess Plateau.Given the strong interdependence between soil and its microbiota,it is imperative to reclaim abandoned lands to maintain soil fertility and sustain its function,which will have significant ecological service implications,particularly with regards to soil conservation in ecologically vulnerable areas. 展开更多
关键词 abandoned lands land-use pattern soil property diversity of soil microbe soil microbial community
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Microspace Revitalization Design around Xihuangcun Railway Station from the Perspective of Urban Renewal
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作者 WU Di XU Fang 《Journal of Landscape Research》 2024年第1期31-34,共4页
Railways within the city carry the historical memory of urban development and are important industrial heritage resources.However,with urban development and changes in transportation functions,railways lose their orig... Railways within the city carry the historical memory of urban development and are important industrial heritage resources.However,with urban development and changes in transportation functions,railways lose their original application value and are gradually left unused or even abandoned,affecting the vitality of the region.Taking the space around Xihuangcun Railway Station as the research object,the public activity space on both sides of the railway is reshaped through five strategies:function revitalization,traffic revitalization,heritage revitalization,spatial revitalization,and landscape revitalization,and the grey area of the city is transformed into a vibrant development zone of the city. 展开更多
关键词 Urban renewal Heritage rejuvenation Abandoned railway Microspace
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Design Strategies for Landscape Transformation of Abandoned Railways in Urban Centers
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作者 WU Jia 《Journal of Landscape Research》 2024年第5期41-45,共5页
The railways have significantly contributed to the economic development of the city.However,with the evolution of the city and adjustments in the industrial structure,the relocation and rerouting of major railway trun... The railways have significantly contributed to the economic development of the city.However,with the evolution of the city and adjustments in the industrial structure,the relocation and rerouting of major railway trunk lines have resulted in the abandonment of numerous urban railways.The abandoned railways,resulting from inadequate management,have transformed into sites for waste disposal and are particularly vulnerable to environmental issues,including land pollution,degradation of vegetation cover,and a decline in ecological diversity.Abandoned railways in urban centers significantly hinder transportation connectivity and adversely influence the aesthetic appeal of the city.The landscape transformation of these abandoned railways is of paramount importance in the context of urban renewal.These railway sites possess significant potential for stock utilization as specialized,underutilized spaces.Through the processes of re-planning,integration,and renewal,previously underutilized spaces can be revitalized and incorporated into the urban landscape in innovative ways.This approach not only enhances the availability of green leisure areas for residents but also contributes to the realization of sustainable urban development. 展开更多
关键词 Urban center Transformation of abandoned railway Abandoned railway landscape
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Analysis of Factors Associated with the Abandonment of Nutritional Recovery among Parents of Severely Malnourished Children Aged 6 to 59 Months in the Health District of Titao, Burkina Faso
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作者 Aminata Gansore Patrice Ngangue +7 位作者 Birama Apho Ly Ludovic K. N’Tcha Douglas Mbang Massom Gbètogo Maxime Kiki Josiane Seu Nestor Bationo Noufou Gustave Nana Fla Koueta 《Open Journal of Nursing》 2024年第9期477-490,共14页
Introduction: In Burkina Faso, undernutrition is a public health problem associated with more than 40% of infant and child mortality. Undernutrition management is complex, and there is often a risk of treatment abando... Introduction: In Burkina Faso, undernutrition is a public health problem associated with more than 40% of infant and child mortality. Undernutrition management is complex, and there is often a risk of treatment abandonment. Studies on this topic have not explored the influence of environmental and therapeutic factors on parental compliance. This study proposes an analysis of factors influencing the abandonment of nutritional recovery by parents of malnourished children aged 6 to 59 months in ambulatory care. Methods: This was a descriptive and exploratory qualitative study. Data collection took place in February 2020. Data were collected from seventeen (17) participants via in-depth interviews (IDI) and direct observation. The IDIs were transcribed verbatim and thematically analyzed using Nvivo software. Results: The results revealed that factors related to the physical environment, such as geographical inaccessibility, pastoral occupation, displacement at auriferous sites, and insecurity, are important causes of nutritional recovery abandonment. They also prove that factors related to the social environment, such as lack of family and social support, feelings of shame, stigmatization, occupation of the mother, and social events, lead to this abandonment. In addition, therapeutic factors such as interruptions of supplies of Ready to Use Therapeutic Food (RUTF), feeling of improvement or worsening of the state of health, recourse to traditional medicine, and ignorance of undernutrition are also associated with this issue. Conclusion: This study highlighted barriers to the abandonment of nutritional recovery among parents of severely malnourished children aged 6 to 59 months in the health district of Titao, Burkina Faso. It is more important to consider these different factors when evaluating care protocols so that policies to reduce child undernutrition can considerably impact the targets. 展开更多
关键词 Nutritional Recovery Severe Acute Malnutrition Environmental Factors Therapeutic Factors ABANDONMENT Burkina Faso
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Landscape Design of Educational Research Base Based on Mine Ecological Restoration:Taking the Restoration of Datu Mine in Xinhe Village,Dadukou District as an Example
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作者 Xi Long Ni Lan Meirong Wu 《Journal of Contemporary Educational Research》 2024年第10期271-278,共8页
With the continuous development of the mining industry,the number of abandoned mines is increasing,which brings many impacts on the geology and ecological environment around the mines.It is urgent to attach great impo... With the continuous development of the mining industry,the number of abandoned mines is increasing,which brings many impacts on the geology and ecological environment around the mines.It is urgent to attach great importance to the ecological management and environmental restoration of abandoned mines.The long-term traditional development path of rural areas,following the model of“pollution first,treatment later,”fails to meet the needs of sustainable development.The contradiction between mine economic development and ecological environment degradation is becoming increasingly prominent,which urgently needs to be solved.Under the guidance of the Party and the state,in order to implement the relevant policies of“green mountains and clear waters are gold and silver mountains,”we emphasize rural green development,and the transformation of rural green development path is imperative.This paper takes Datu Mine in Xinhe Village,Dadukou District,Chongqing as the research object,combines rural ecological development as the research basis,and innovatively integrates the“educational research”model,aiming to provide practical strategies for the sustainable development of rural landscapes in abandoned mines. 展开更多
关键词 Ecological restoration Educational research Abandoned mines
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Prospects for the transformation and development of carbon storage in abandoned mines of coal enterprises from the perspective ofcarbon neutrality 被引量:5
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作者 Xin Lyu Tong Zhang +1 位作者 Liang Yuan Juejing Fang 《International Journal of Coal Science & Technology》 EI CAS CSCD 2023年第3期24-40,共17页
Under the carbon neutrality goal,coal enterprises must seek breakthroughs from abandoned mines,develop new resources in the new era,turn problems into countermeasures,and participate in the carbon emissions market,for... Under the carbon neutrality goal,coal enterprises must seek breakthroughs from abandoned mines,develop new resources in the new era,turn problems into countermeasures,and participate in the carbon emissions market,for contributing to the accomplishment of the national strategic goal of carbon neutrality.To this end,we investigated the relevant national policies and regulations to clarify the boundaries disclosed by the carbon information of enterprises,understood the development direction of carbon storage in abandoned mines,and clarified the transformation and development of carbon storage in aban-doned mines.We made a few suggestions:(1)China should learn from its past experience and other countries to develop the energy industry with Chinese characteristics and reform the economic system.(2)Coal enterprises must actively respond to the national carbon information disclosure policy,clarify their own responsibilities and carbon emission boundaries.(3)It is necessary to proactively obtain advanced knowledge and plan carbon storage pathways for abandoned mines.(4)Devel-opment problems of coal enterprises should be deduced using cases.The'dual carbon'goals should be achieved steadily step-by-step.(5)Three measures,i.e.improving the existing resource structure,coordinating the information of abandoned mines,and promoting the cultivation of scientific and technological talents. 展开更多
关键词 Mining engineering Abandoned mines Carbon neutrality Carbon emission rights Carbon tax
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Effect of mechanical vibration process parameters on the cement plugs properties for abandoned wells 被引量:1
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作者 Hang-Ming Liu Yang-Ye He +6 位作者 Ji-Fang Wan Lin Chen Xian-Zhong Yi Yuan-Hua Zhou Yu-Xian He Xiang-Gui Ming Lu Ren 《Petroleum Science》 SCIE EI CAS CSCD 2023年第4期2428-2441,共14页
A high-quality plug of the abandoned wellbore is considered an essential technical aspect of the oil and gas well abandonment technology system. This paper presents a method of active mechanical excitation to enhance ... A high-quality plug of the abandoned wellbore is considered an essential technical aspect of the oil and gas well abandonment technology system. This paper presents a method of active mechanical excitation to enhance the quality of wellbore plug barriers. An indoor simulation platform is developed, and the effects of different combinations of vibration frequency, amplitude and duration on the properties of the wellbore plug cement material are investigated. It is observed that the optimal combination of excitation parameters occurs at a vibration frequency of 15 Hz, a vibration time of 6 min, and a vibration amplitude of 3 mm. Compared with the condition without the vibration process, the cementing strength, compressive strength, and tensile strength of wellbore cement plug with the optimal mechanical vibration process could increase by 51%, 38% and 20%, respectively, while the porosity decreases by 5%. As determined by scanning electron microscopy of the set cement's microstructure, mechanical vibration effectively eliminates internal porosity and improves the set cement's density. The optimal excitation parameters obtained from the test can guide the design of the vibration plugging tool. The designed vibration plugging tool is simulated in the near field. The cement plug cementation quality tester tests the vibrating and non-vibrating samples, and the cementation ratio is calculated. The test results show that the average cementation ratio of vibrating samples is 0.89375, and that of non-vibrating samples is 0.70625, and the cementation quality is improved by 27%. It is concluded that it not only provides essential data for the design of mechanical vibration plug apparatus, on-site vibration plugs, and the development of operational specifications for vibration plugs, but also provides solid engineering guidance. 展开更多
关键词 Plugging and abandonment Cement plug VIBRATION Mechanical properties MICROSTRUCTURE
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Optimal Scheduling Method of Cogeneration System with Heat Storage Device Based on Memetic Algorithm 被引量:1
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作者 Haibo Li YibaoWang +2 位作者 Xinfu Pang Wei Liu Xu Zhang 《Energy Engineering》 EI 2023年第2期317-343,共27页
Electric-heat coupling characteristics of a cogeneration system and the operating mode of fixing electricity with heat are the main reasons for wind abandonment during the heating season in the Three North area.To imp... Electric-heat coupling characteristics of a cogeneration system and the operating mode of fixing electricity with heat are the main reasons for wind abandonment during the heating season in the Three North area.To improve the wind-power absorption capacity and operating economy of the system,the structure of the system is improved by adding a heat storage device and an electric boiler.First,aiming at the minimum operating cost of the system,the optimal scheduling model of the cogeneration system,including a heat storage device and electric boiler,is constructed.Second,according to the characteristics of the problem,a cultural gene algorithm program is compiled to simulate the calculation example.Finally,through the system improvement,the comparison between the conditions before and after and the simulation solutions of similar algorithms prove the effectiveness of the proposed scheme.The simulation results show that adding the heat storage device and electric boiler to the scheduling optimization process not only improves the wind power consumption capacity of the cogeneration system but also reduces the operating cost of the system by significantly reducing the coal consumption of the unit and improving the economy of the system operation.The cultural gene algorithm framework has both the global evolution process of the population and the local search for the characteristics of the problem,which has a better optimization effect on the solution. 展开更多
关键词 Combined heat and power generation heat storage device memetic algorithm simulated annealing wind abandonment
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Characteristics and driving factors of abandoned cultivated land in the hilly regions of southern China:A case study in Longnan,Jiangxi Province
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作者 CHEN Ze-bin CHEN Yong-lin +4 位作者 LI Chao-jun LIN Jian-ping CHEN Pei-ru SUN Wei-wei WAN Zhi-wei 《Journal of Mountain Science》 SCIE CSCD 2023年第5期1483-1498,共16页
The abandonment of cultivated land in southern China was gradually obvious.This research aims to provide a reference for solving the abandonment of cultivated land in hilly regions and promote rural development in Chi... The abandonment of cultivated land in southern China was gradually obvious.This research aims to provide a reference for solving the abandonment of cultivated land in hilly regions and promote rural development in China.We examined Longnan county located in the hilly regions of southern China as an example,where abandoned cultivated land is very common.We analyzed its land use data with a field survey to identify the abandoned cultivated land and geospatial characteristics.From the two aspects of social and natural factors,we analyzed the factors driving cultivated land abandonment with the help of Geodetector.The results showed that in 2019,the total area of the abandoned cultivated land in Longnan county was 4,962.35 hm^(2),covering 39.51% of this region.Among the topographic factors,the abandonment rate is positively correlated with elevation and slope gradient,but not with slope direction.Among the land parcel conditions,the abandonment rate is positively correlated with the access to road network and cultivation distance from settlement.At the county level,the abandonment of cultivated land in study area was affected by multiple factors,among which,the direct factor was the reduction in the labor force,such as the decrease of farming laborers and the increase of female population,which made farming unsustainable.Changes in production factors also promoted transformations in farmers’motivation to engage in production,such as the decrease of grain crops and the increase of cash crops,which was the indirect factor affecting cultivated land abandonment.The development of the rural nonagricultural industry affected farmers’enthusiasm,such as the decrease of farming households,which was the fundamental factor leading to cultivated land abandonment in this area. 展开更多
关键词 Cultivated land abandonment Spatial distribution Geodetector Driving factor Hilly region County level
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Multiple grain-size fraction analysis of heavy minerals and the provenance identification of sediments from the abandoned Huanghe River,eastern China
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作者 Mengyao WANG Bingfu JIN Jianjun JIA 《Journal of Oceanology and Limnology》 SCIE CAS CSCD 2023年第3期921-935,共15页
The quantitative analysis of sediment sources in a sink is an important scientific topic and challenge in provenance research.The characteristics of heavy minerals,combined with the geochemical constituents of detrita... The quantitative analysis of sediment sources in a sink is an important scientific topic and challenge in provenance research.The characteristics of heavy minerals,combined with the geochemical constituents of detrital grains,provide a reliable provenance-tracing approach.We developed a mineral identification method to analyze the multiple grain-size fraction of sediments,from which the elemental geochemistry of hornblende was used to compare the characteristics of sediments from the Huaihe River and Huanghe(Yellow)River in eastern China.Elements that were statistically identified as being able to discriminate sediment provenance were employed to perform a quantitative analysis of the sources of sediments of the abandoned Huanghe River.Results reveal that the Huaihe River is characterized by a high amphibole content of>60%and that the Huanghe and abandoned Huanghe rivers have greater abundances of limonite and carbonate minerals compared with those of the Huaihe River.The contents of trace elements and rare earth elements in hornblende show that the sediments of the abandoned Huanghe River are similar to those of the Huanghe River but different from those of the Huaihe River.Furthermore,chemical mass balance was used to calculate the relative contributions of different provenances of sediment from the abandoned Huanghe River,and nine trace elements of hornblende were identified as discriminators of provenance.Approximately 2%of the hornblende in the abandoned Huanghe River is derived from the Huaihe River and 98%from the Huanghe River.Considering the proportion of hornblende in the total sediment,it is inferred that the contribution of Huaihe River sediment to the abandoned Huanghe River is approximately 0.5%.This study shows that mineral analysis using multiple grain-size fractions(within the wide range of 1Φto 6Φ)with assessment in elemental geochemistry of hornblende can characterize the provenance of fluvial material in coastal zones. 展开更多
关键词 quantitative provenance analysis heavy mineral multiple grain-size fraction HORNBLENDE elemental geochemistry fluvial sediment the abandoned Huanghe River
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Abandonment and Recovery Operation of Steel Lazy-Wave Riser in Deepwater by Controlled Vessel and Cable Velocity Rate
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作者 GU Ji-jun HUANG Jun +3 位作者 GAO Lei CHEN Lei-lei JIA Ji-chuan WANG Shu-jiang 《China Ocean Engineering》 SCIE EI CSCD 2023年第1期29-41,共13页
Evaluation of abandonment and recovery operation of steel lazy-wave riser in deepwater is presented in this paper.The calculation procedure includes two single continuous SLWR and cable segments, which are coupled tog... Evaluation of abandonment and recovery operation of steel lazy-wave riser in deepwater is presented in this paper.The calculation procedure includes two single continuous SLWR and cable segments, which are coupled together to form the overall mathematical model. Then the equilibrium equations of SLWR and cable are established based on minimum total potential energy principle. The coupled equations are discretized by the finite difference method and solved by Newton-Raphson technique in an iterative manner. The present method is validated by well-established commercial code OrcaFlex. Recovery methods by considering different ratios of vessel’s moving velocity to cable’s recovery velocity are evaluated to optimize the abandonment and recovery operation. In order to keep the tension more stable during the recovery process, the rate ratio before leaving the seabed is increased, and the rate ratio after leaving the seabed is reduced. 展开更多
关键词 steel lazy-wave riser ABANDONMENT RECOVERY
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Abandoned land identification in karst mountain area based on time series SAR characteristics at geo-parcels scale
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作者 ZHOU Zhong-fa WANG Ling-yu +6 位作者 CHEN Quan LUO Jian-cheng ZHAO Xin ZHANG Shu ZHANG Wen-hui LIAO Juan LYU Zhi-jun 《Journal of Mountain Science》 SCIE CSCD 2023年第3期792-809,共18页
Mapping abandoned land is very important for accurate agricultural management.However,in karst mountainous areas,continuous high-resolution optical images are difficult to obtain in rainy weather,and the land is fragm... Mapping abandoned land is very important for accurate agricultural management.However,in karst mountainous areas,continuous high-resolution optical images are difficult to obtain in rainy weather,and the land is fragmented,which poses a great challenge for remote sensing monitoring of agriculture activities.In this study,a new method for identifying abandoned land is proposed:firstly,a few Google Earth images are used to transform arable land into accurate vectorized geo-parcels;secondly,a time-series data set was constructed using Sentinel-1A Alpha parameters for 2020 on each farmland geoparcel;thirdly,the semi-variation function(SVF)was used to analyze the spatial-temporal characteristics,then identify abandoned land.The results show:(1)On the basis of accurate spatial information and boundary of farmland land,the SAR time-series dataset reflects the structure and time-series response.abandoned land with an accuracy of 80.25%.The problem of remote sensing monitoring in rainy regions and complex surface areas is well-resolved.(2)The spatial heterogeneity of abandoned land is more obvious than that of cultivated land within geoparcels.The step size for significant changes in the SVF of abandoned land is shorter than that of cultivated land.(3)The SVF time sequence curve presented a strong peak feature when farmland was abandoned.This reveals that the internal spatial structure of abandoned land is more disordered and complex.It showed that time-series variations of spatial structure within cultivated land have broader applications in remote sensing monitoring of agriculture in complex imaging environments. 展开更多
关键词 Sentinel-1 SAR Abandoned farmland Semi variogram function Farmland geo parcel Time seriescharacteristics Texture feature Karst mountainous area
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Enhanced Electric Power Adaptability Using Hybrid Pumped-Hydro Technology with Wind and Photovoltaic Integration
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作者 Uwem O.Ikitde Abayomi A.Adebiyi +1 位作者 Innocent E.Davidson Ayodeji S.Akinyemi 《Energy Engineering》 EI 2023年第9期1939-1961,共23页
The integration of solar and wind energy into the electrical grid has received global research attention due to their unpredictable characteristics.Because wind energy varies across all timescales of utility activity,... The integration of solar and wind energy into the electrical grid has received global research attention due to their unpredictable characteristics.Because wind energy varies across all timescales of utility activity,renewable energy generation should be supplemented and enhanced,from real-time,minute-to-minute variations to annual alterations influencing long-termstrategy.Wind energy generation does not only fluctuate but is also challenging to accurately forecast the timeframes of significance to electricity decision makers;day-ahead and long-term making plans of framework sufficiency such as meeting the network peak load annually.A utility that integrates wind and solar energy into its electricity mix would understand how to adapt to uncertainty and variability in operations while sustaining grid stability.Due to hydropower’s adaptability,a system using hydropower as one of its generating resources could be precisely adapted to absorb the variability of wind and solar energy.The objective of this research study is to create a hybrid system comprising hydro-wind and solar(Hybrid-HWS)integration for power balancing in an isolated electrical network in Klipkop village,Pretoria region,South Africa.The desirability of designing and building goaf storage tank in regard to capability,the fullness of line throughoutwater pumping,dispensing,storage tank spillage,and pressure difference throughout liquid flow within the storage tanks were preliminary assessed using geotechnical and weather forecasting data from a distinctive area of Klipkop town in Pretoria,South Africa.Different facility hours premised on daylight accessibility are scheduled to balance maximum load at early and late hours.However,in the scenario of electrical power,time shift requiring storage for extended periods of time,such as in terms of hours,Hybrid-HWS has been found to have a crucial role.The results of simulations showed a coordinated process design for Hybrid-HWS Energy Storage(ES)to determine everyday strategic planning in reducing the variability of the system resulting from wind-solar-pumped hydro ES output inadequacies and satisfy daily load demands.It could be recommended that by considering the adaptability characteristics,extremely rapidly,ramping,peaking support and maximum stabilizing aid of the system could be archived with pump-hydro into the energy mix which can provide specific guidelines for energy policymakers. 展开更多
关键词 Pumped hydro storage(PHS) hybrid hydro-wind-solar technique abandoned coal mine power balancing
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Regeneration Potential of Woody Species at the Side of Secondary Roads Post-Logging of Loundoungou-Toukoulaka Forest Management Unit, Republic of the Congo
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作者 Chauvelin Douh Larisa Mbouchi Malonga +4 位作者 Donatien N’zala Belvina Chardène Mabengo Christian Moussoumbou Saint Fédriche Ndzaï Félix Koubouana 《Natural Resources》 2023年第7期102-120,共19页
Natural regeneration is the basis of a dynamic and demographic balance of plant populations. The objective of this study was to assess the natural regeneration potential of woody species along secondary roads post-log... Natural regeneration is the basis of a dynamic and demographic balance of plant populations. The objective of this study was to assess the natural regeneration potential of woody species along secondary roads post-logging abandoned since 2008 and 2018. In the two Annual Allowable Cuts (AAC 2008 and AAC 2018), 24 regenerating sub-plots (i.e. 12 sub-plots for AAC 2008 and 12 sub-plots for AAC 2018) with a unit area of 5 m × 5 m were delimited with a total area of 0.06 ha (i.e. 0.03 ha for each AAC). The abundance and diversity of woody species were respectively inventoried and estimated. Two estimators of the specific richness were used to estimate the floristic diversity of each Annual Allowable Cuts (AAC). The results reveal globally 88 woody species in the AAC 2008 and 241 woody species in the AAC 2018, with respective average densities of 2933 stem/ha and 8033 stem/ha. There was a very highly significant difference between the mean densities of the two AAC (Kruskal-Wallis test;H = 2.36, p-value < 0.000). The results also highlight a great diversity and a relatively high abundance of woody species in the 2018 AAC compared to the 2008 AAC. Also, the spatial structuring of the sub-plots on the basis of Principal Component Analysis (PCA) demonstrates that the floristic composition of the two AAC is globally different. The study suggests silvicultural interventions and the long-term assessment of regenerating woody species along abandoned secondary roads in order to guarantee the sustainable management of their population. 展开更多
关键词 Regeneration Dynamics Woody Species Abandoned Secondary Roads Forest Management Unit
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城市污泥在矿山废弃地复垦的应用探讨 被引量:92
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作者 莫测辉 蔡全英 +1 位作者 王江海 吴启堂 《生态学杂志》 CAS CSCD 北大核心 2001年第2期44-47,51,共5页
Based on the analysis of the existing problems in reclaiming abandoned mining land and their negative effect on the ecological environment,and in view of the limited factors to reclaim abandoned mining land,this paper... Based on the analysis of the existing problems in reclaiming abandoned mining land and their negative effect on the ecological environment,and in view of the limited factors to reclaim abandoned mining land,this paper puts forward the suggestions of using sewage sludge as an alternative in mining land reclamation.Application of sewage sludge in reclamation has beneficial effects, such as increasing organic matter content, preventing soil erosion,recovering vegetation,and promoting microbial population and its activities Unfavorable factors including heavy metal and organic pollutant for applications of sewage sludge and their countermeasures are also discussed. 展开更多
关键词 sewage sludge abandoned mining land reclamation.
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Plant Traits and Soil Chemical Variables During a Secondary Vegetation Succession in Abandoned Fields on the Loess Plateau 被引量:80
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作者 王国宏 《Acta Botanica Sinica》 CSCD 2002年第8期990-998,共9页
Species dynamics in terms of both plant biological traits, ecological strategies and species richness as well as soil chemical variables during a secondary succession in abandoned fields on the Loess Plateau along a t... Species dynamics in terms of both plant biological traits, ecological strategies and species richness as well as soil chemical variables during a secondary succession in abandoned fields on the Loess Plateau along a temporal sere from 3 a to 149 a were studied. The results indicated that (I) Soil total C and N increased while soil pH, total K and Na decreased with years since abandonment. No noticeable trend was found in the case of soil P along the successional sere. On the other hand, total CaO of the surface layer (0 - 10 cm) decreased, but that of the two deeper layer, (20 - 30 cm, 40 - 50 cm) increased with years since abandonment. Soil C, N, K and P decreased, while Na, CaO and soil pH increased with increasing soil depth. (2) Species richness peaked at both mid-stage of the successional sere and the intermediate portion of soil chemical variables gradient. (3) An ideal dominant species in the early successional stage were annuals with stable seed pool, CR-life strategy, S-regeneration strategy, and strong competitive ability on relatively poor soil, while perennials capable of intensive lateral spread and colonal ability, requiring high nutrient supply, and having Clife strategy would be the dominant species in the subsequent stages. Plant traits, such as perennial-life history, C-, CR-, SC-, SR-, S- and R-life strategies, W-, S-, Bs- VBs- and V-regeneration strategies, were over- represented throughout the whole sere among the other species. (4) Some traits, such as C-, SC-life strategies, ability of clonality, perennial-life history, well-developed lateral spread ability, V- and VBs-regeneration strategies, seed animal. dispersal mode, flowering time of autumn, fruit types of legumen and nut, were more or less correlated with increased soil total C, N and K, while S-, SR-, R-, CR-life strategies, annual-, biannual-life history, non-clonal ability, S-regeneration strategy, poor lateral spread ability, and fruit types of utricle, capsule were associated with increased soil total Na, CaO and pH. The results suggested that steppes should be the dominant native vegetation coinciding with the large-scaled eco-climatic conditions on the Loess Plateau. 展开更多
关键词 abandoned fields plant trait soil chemical variable SUCCESSION Loess Plateau
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