Environmental Research Communications最新文献

Evaluating D-InSAR performance to detect small water level fluctuations in two small lakes in Sweden 评估 D-InSAR 在探测瑞典两个小湖泊的微小水位波动方面的性能

IF 2.9 4区环境科学与生态学

Environmental Research Communications Pub Date : 2024-09-12 DOI: 10.1088/2515-7620/ad7701

Saeid Aminjafari, Ian A Brown and Fernando Jaramillo

{"title":"Evaluating D-InSAR performance to detect small water level fluctuations in two small lakes in Sweden","authors":"Saeid Aminjafari, Ian A Brown and Fernando Jaramillo","doi":"10.1088/2515-7620/ad7701","DOIUrl":"https://doi.org/10.1088/2515-7620/ad7701","url":null,"abstract":"Monitoring lake water level fluctuations is critical for managing water resources, predicting the impacts of climatic change, and preserving ecosystem services lakes provide. However, traditional gauging stations are insufficient to monitor all lakes worldwide due to the large number of existing lakes, the challenges of installation and maintenance, and the remote locations of some. Although satellite altimetry is an alternative for measuring water levels, it cannot monitor small lakes effectively. This study evaluates the potential of Differential Interferometric Synthetic Aperture Radar (D-InSAR) for tracking minor water level changes in small lakes, a method more typically used in wetland studies. We investigate two Swedish lakes using Sentinel-1A and Sentinel-1B data from 2019, generating six-day interferograms and filtering out those with in situ water level changes exceeding one phase cycle. Our results show that D-InSAR can detect small water level changes with Lin’s correlations up to 0.63 and 0.89 and RMSE values of approximately 9 and 4 mm, respectively. These results evidence the potential of future L-band SAR missions with larger wavelengths, such as the NASA-ISRO SAR (NISAR) of the National Aeronautics and Space Administration (NASA) and the Indian Space Research Organisation (ISRO), to track water level changes in lakes and aid water tracking missions such as the SWOT (Surface Water and Ocean Topography).","PeriodicalId":48496,"journal":{"name":"Environmental Research Communications","volume":null,"pages":null},"PeriodicalIF":2.9,"publicationDate":"2024-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142214874","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Study on the characteristics and scenario simulation of land use change in the Chaohu Lake Basin, China 中国巢湖流域土地利用变化特征与情景模拟研究

IF 2.9 4区环境科学与生态学

Environmental Research Communications Pub Date : 2024-09-12 DOI: 10.1088/2515-7620/ad75ed

Yunfeng Ruan, Chunyu Jiao and Yashu Duan

{"title":"Study on the characteristics and scenario simulation of land use change in the Chaohu Lake Basin, China","authors":"Yunfeng Ruan, Chunyu Jiao and Yashu Duan","doi":"10.1088/2515-7620/ad75ed","DOIUrl":"https://doi.org/10.1088/2515-7620/ad75ed","url":null,"abstract":"Effectively evaluating the historical and future land use/cover change (LUCC) is significant for effective land use planning and management, ecological conservation, and restoration. Taking the Chaohu Lake Basin (CLB) as the study area, GIS technology and geographic detector were used to quantitatively analyze the change characteristics and driving factors of LUCC under the three periods in 2000, 2010, and 2020 of the CLB. This study aimed to comprehend the alterations that have transpired over the last two decades. In addition, the PLUS model was utilized to forecast LUCC trends under three scenarios: natural development, urban development, and ecological protection by 2030 in the CLB. The results suggest a significant decrease of the cultivated land area, while a considerable increase for the construction land area from 2000 to 2020 in the CLB. The expansion of the construction land area was mainly driven by the conversion of cultivated land area. Additionally, the slope was identified as the primary factor influencing LUCC, with q-values of 0.275, 0.266, and 0.258 in 2000, 2010, and 2020, respectively. The interaction between slope and soil type, distance to the trunk road and the secondary trunk road, and GDP was strong. The explanatory capacity of socioeconomic factors demonstrated a steady increase. The simulation results indicate that a decrease in cultivated land area and an increase in construction land area still occurred by 2030 in the CLB, particularly in the urban development scenario. Nonetheless, a notable deceleration of change was appeared in the ecological protection scenario. The alterations in forest and grassland areas were not significant. However, the water bodies area continued to enlarge, although the expansion was not substantial. The study results can provide policy references for the scientific management and long-term strategic planning of land resources in the CLB.","PeriodicalId":48496,"journal":{"name":"Environmental Research Communications","volume":null,"pages":null},"PeriodicalIF":2.9,"publicationDate":"2024-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142214892","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Modeling N2O emissions with remotely sensed variables using machine learning 使用机器学习利用遥感变量建立一氧化二氮排放模型

IF 2.9 4区环境科学与生态学

Environmental Research Communications Pub Date : 2024-09-09 DOI: 10.1088/2515-7620/ad707c

Paul R Adler, Hai Nguyen, Benjamin M Rau and Curtis J Dell

{"title":"Modeling N2O emissions with remotely sensed variables using machine learning","authors":"Paul R Adler, Hai Nguyen, Benjamin M Rau and Curtis J Dell","doi":"10.1088/2515-7620/ad707c","DOIUrl":"https://doi.org/10.1088/2515-7620/ad707c","url":null,"abstract":"Nitrous oxide is the largest source of greenhouse gas emissions from crop production. There is significant interest in targeting marginal lands for growing biomass crops, however little information is available on how this will affect N2O emissions from these crops. Furthermore, to characterize N2O emission at the farm level to quantify mitigation using measurements is time intensive, costly, and impractical. We selected a highly diverse watershed varying in soil texture and topography to compare two approaches for modeling soil N2O emissions using machine learning, intensive measurements of soil environment and climate variables, with the other only using remotely sensed variables. We confirmed that soil nitrogen was the most important variable followed by soil environment as influence by soil characteristic, topography, and climate. We also found that the machine learning model built on remotely sensed variables performed as well as when direct site level measurements were available. This finding supports the potential of using remotely sensed data to build machine learning models to characterize soil N2O emissions without the need for intensive soil measurements for entity level assessments.","PeriodicalId":48496,"journal":{"name":"Environmental Research Communications","volume":null,"pages":null},"PeriodicalIF":2.9,"publicationDate":"2024-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142226934","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Optimisation of decision-making on risk management strategy for the hydromelioration systems in biosphere reserves 优化生物圈保护区水质净化系统风险管理战略决策

IF 2.9 4区环境科学与生态学

Environmental Research Communications Pub Date : 2024-09-09 DOI: 10.1088/2515-7620/ad75ef

Tetiana Pokshevnytska and Yuliia Khrutba

{"title":"Optimisation of decision-making on risk management strategy for the hydromelioration systems in biosphere reserves","authors":"Tetiana Pokshevnytska and Yuliia Khrutba","doi":"10.1088/2515-7620/ad75ef","DOIUrl":"https://doi.org/10.1088/2515-7620/ad75ef","url":null,"abstract":"The field of nature conservation in Ukraine is currently experiencing a profound crisis. In light of the mounting risks to Ukraine’s ecosystems, it is of paramount importance that conservation planning incorporates risk management strategies. In the aftermath of the Chernobyl disaster, the management of water bodies in the Exclusion Zone assumed paramount importance, given that the rivers had become the primary conduit for the transportation of radioactive substances. It is therefore imperative to evaluate the risks and vulnerabilities of climate change on Ukraine’s most developed economic sectors, population, and natural ecosystems. This will facilitate comprehension of the prospective consequences of climate change, ascertain the extent of potential losses, and inform decision-making aimed at reducing or preventing such losses in a timely manner. One of the primary challenges facing specialists at the Chornobyl Radiation and Ecological Biosphere Reserve, in addition to other organisations and enterprises of the State Agency of Ukraine on Exclusion Zone Management and scientific institutions, is the assessment of the feasibility of hydromelioration systems. It is of the utmost importance that a scientifically sound methodological approach be employed in order to ensure the reliability and validity of the results obtained through the assessment of risks and vulnerabilities to climate change. In this context, the utilisation of adaptive methodologies is of paramount importance for the development of risk management strategies. One such methodology is the Methodology for Risk Analysis and Information Management for Strategic Ecosystems (MARISCO). This article considers the potential deployment of the MARISCO adaptive method as a universal methodology for the analysis of environmental issues, with a view to informing decision-making on risk management strategies in the Chornobyl Radiation and Ecological Biosphere Reserve.","PeriodicalId":48496,"journal":{"name":"Environmental Research Communications","volume":null,"pages":null},"PeriodicalIF":2.9,"publicationDate":"2024-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142214880","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

SMOS captures variations in SSS fronts during El Niño and La Niña SMOS 捕捉到厄尔尼诺和拉尼娜期间 SSS 锋面的变化

IF 2.9 4区环境科学与生态学

Environmental Research Communications Pub Date : 2024-09-09 DOI: 10.1088/2515-7620/ad744a

Jiahao Li and Ling Du

{"title":"SMOS captures variations in SSS fronts during El Niño and La Niña","authors":"Jiahao Li and Ling Du","doi":"10.1088/2515-7620/ad744a","DOIUrl":"https://doi.org/10.1088/2515-7620/ad744a","url":null,"abstract":"The launch of the Soil Moisture and Ocean Salinity (SMOS) satellite has promoted research on sea surface salinity (SSS) and salinity fronts (SF). The SF in the central Pacific Ocean is influenced by El Niño and La Niña events, and the physical processes involved are complex. In this study, we evaluated the ability of the SMOS product from the Barcelona Expert Centre (BEC) to retrieve SF using a simple and intuitive method. Furthermore, this study investigated seasonal variations in the SF and its response to El Niño and La Niña events. The accuracy of the SMOS BEC L4 SSS is sufficient for studying SF. By selecting reasonable SF thresholds and analyzing its locations and intensities, in the central equatorial Pacific Ocean, SF can be divided into two: northern and southern SF. The variability in the northern SF is primarily influenced by the migration of the intertropical convergence zone (ITCZ), whereas both freshwater flux and salt advection are the primary factors in the southern SF. They correspond to El Niño and La Niña events through freshwater flux and salt advection. These findings can provide information for the study of the SF based on satellite data and enhance our understanding of El Niño Southern Oscillation (ENSO) dynamics.","PeriodicalId":48496,"journal":{"name":"Environmental Research Communications","volume":null,"pages":null},"PeriodicalIF":2.9,"publicationDate":"2024-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142214896","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Economic and environmental assessment of the Korea urban railway and its greenhouse gas mitigation potential 韩国城市铁路及其温室气体减排潜力的经济和环境评估

IF 2.9 4区环境科学与生态学

Environmental Research Communications Pub Date : 2024-09-09 DOI: 10.1088/2515-7620/ad5a6b

Wonwoo Jeong and HyeMin Park

{"title":"Economic and environmental assessment of the Korea urban railway and its greenhouse gas mitigation potential","authors":"Wonwoo Jeong and HyeMin Park","doi":"10.1088/2515-7620/ad5a6b","DOIUrl":"https://doi.org/10.1088/2515-7620/ad5a6b","url":null,"abstract":"Railways can simultaneously transport large quantities of freight and passengers, making them energy-efficient and economical modes of transportation. Changing the materials that constitute a significant portion of rail track systems can help mitigate climate change. Gravel and concrete trackbed methods are commonly employed in railway construction. This study proposes the utilization of the asphalt concrete trackbed method, which is currently being researched and developed in South Korea, in addition to traditional gravel and cement concrete methods, and presents its economic feasibility and environmental benefits. The asphalt concrete trackbed method, which has already been implemented in regions such as China, Australia, and Europe, can also be applied in other areas. This study analyzed the carbon emissions and economic feasibility in the construction, usage, and disposal stages of cement concrete and asphalt concrete trackbeds. Previous research on carbon emissions analysis has faced challenges in applying geographical and climatic, as well as energy sources, to individual cases in the context of construction in Korea. Using the Korean Life Cycle Inventory database, this study indicated that asphalt concrete exhibits approximately 2.65-times lower carbon emissions than cement concrete. In Korea, railway construction involves 1,998 tons of asphalt concrete mixture, 1,820 cubic meters of cement concrete, and 59 tons of rebar per kilometer. Furthermore, the asphalt concrete trackbed method shows potential cost savings of approximately 29,000 EUR when converted to the 2021 EAU value. Thus, asphalt concrete trackbeds not only provide environmental benefits, they are also economically viable. However, further research is required to establish precise standards for on-site construction. This study is expected to provide foundational data for promoting the widespread adoption of asphalt concrete trackbeds in areas that produce asphalt concrete.","PeriodicalId":48496,"journal":{"name":"Environmental Research Communications","volume":null,"pages":null},"PeriodicalIF":2.9,"publicationDate":"2024-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142214878","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Experiment study on temporal stability of soil moisture content in ecological slopes under different vegetation covers 不同植被覆盖下生态坡地土壤含水量时间稳定性试验研究

IF 2.9 4区环境科学与生态学

Environmental Research Communications Pub Date : 2024-09-04 DOI: 10.1088/2515-7620/ad6ee4

Xiaoxue Luo, Xinlong Zhou, Henglin Xiao, Qiang Ma, Yutian Yang, Kaimeng Hu

{"title":"Experiment study on temporal stability of soil moisture content in ecological slopes under different vegetation covers","authors":"Xiaoxue Luo, Xinlong Zhou, Henglin Xiao, Qiang Ma, Yutian Yang, Kaimeng Hu","doi":"10.1088/2515-7620/ad6ee4","DOIUrl":"https://doi.org/10.1088/2515-7620/ad6ee4","url":null,"abstract":"Temporal stability of soil moisture distribution is crucial to revealing the hydrological process of slope, but rarely accounted for during ecological restoration for engineering slopes. In this study, the effects of ecological restoration with different vegetations on soil moisture distribution were assessed by introducing temporal stability analysis. First, the ecological model slopes with grass and shrub covers were constructed to explore soil moisture distribution at the depth of 0 ∼ 100 cm. Then the spatial variability and correlation of soil moisture in ecological slope were analyzed. The similarity of the spatial distribution patterns among different periods were explored by temporal stability indices. Finally, the representative locations of soil moisture for each ecological slope were obtained and discussed. The results showed that soil moisture distribution was largely influenced by vegetation and rainfall. The similarity of spatial distribution patterns in ecological slopes with different vegetations differed from each other. Due to the difference in hydrological effects. The spatial distribution of soil moisture in slope was less similar in time under Cynodon dactylon cover, while it was better under Multiflora magnolia. Based on relative difference and time stability index, most of best representative locations were distributed at the top of the slope, followed by the middle of the slope. The study provides a theoretical basis for the rational monitoring point design of soil moisture content and a guide for the ecological restoration of engineering slopes.","PeriodicalId":48496,"journal":{"name":"Environmental Research Communications","volume":null,"pages":null},"PeriodicalIF":2.9,"publicationDate":"2024-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142214891","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Evaluating rainbowing for ocean alkalinity enhancement 评估雨流对提高海洋碱度的作用

IF 2.9 4区环境科学与生态学

Environmental Research Communications Pub Date : 2024-09-03 DOI: 10.1088/2515-7620/ad707b

Riccardo Bianchi, Samuele Abbate, Andrew Lockley, Antonella Abbà, Francesco Campo, Selene Varliero, Mario Grosso, Stefano Caserini

{"title":"Evaluating rainbowing for ocean alkalinity enhancement","authors":"Riccardo Bianchi, Samuele Abbate, Andrew Lockley, Antonella Abbà, Francesco Campo, Selene Varliero, Mario Grosso, Stefano Caserini","doi":"10.1088/2515-7620/ad707b","DOIUrl":"https://doi.org/10.1088/2515-7620/ad707b","url":null,"abstract":"Ocean Alkalinity Enhancement (OAE) is a technique proposed to address ocean acidification and global warming. This study examines rainbowing (i.e. water jets pumped into the air from ships) for the slaked lime slurry distribution. The fluid dynamic behaviour—both the in-air trajectory and subsurface—was studied using the Smoothed Particle Hydrodynamics method. Various outflow velocities were simulated for calm seas; different dilution factors and environmental slaked lime concentration spikes have been found. Linking slurry concentration to pH, discharge conditions that avoid damage to marine biota have been identified. A preliminary cost analysis compares rainbowing to ship-wake discharge. Rainbowing requires high power consumption to project large volumes of water far from ships. Very high dilution is needed, mainly because of the artificial requirement not to momentarily exceed 24-hour environmental pH limits; the effect of ocean turbulence on instantaneous pH peaks is negligible and is not considered in the analysis. Emissions due to energy consumption almost equalize carbon dioxide removed during discharge, making the method inefficient (only 176 <italic toggle=\"yes\">kg</italic> of CO<sub>2</sub> removed per ton of slaked lime spread). Previous ship-wake discharge analysis shows greater OAE performance and lower cost (5.5 € versus 388 € per ton of CO<sub>2</sub> removed). In conclusion—based on the conservative environmental limits imposed, and the specific modeling undertaken—rainbowing is not demonstrated as an efficient method for OAE.","PeriodicalId":48496,"journal":{"name":"Environmental Research Communications","volume":null,"pages":null},"PeriodicalIF":2.9,"publicationDate":"2024-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142214893","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Travel footprints in the nordics 北欧的旅行足迹

IF 2.9 4区环境科学与生态学

Environmental Research Communications Pub Date : 2024-09-03 DOI: 10.1088/2515-7620/ad718d

Johanna Raudsepp, Michał Czepkiewicz, Jukka Heinonen, Áróra Árnadóttir

引用次数: 0

Coupled model intercomparison project phase 6 (CMIP6) high resolution model intercomparison project (HighResMIP) bias in extreme rainfall drives underestimation of amazonian precipitation 耦合模式相互比较项目第 6 阶段（CMIP6）高分辨率模式相互比较项目（HighResMIP）极端降雨量的偏差导致低估了亚马孙降水量

IF 2.9 4区环境科学与生态学

Environmental Research Communications Pub Date : 2024-09-02 DOI: 10.1088/2515-7620/ad6ff9

Robinson Negron-Juarez, Michael Wehner, Maria Assunção F Silva Dias, Paul Ullrich, Jeffrey Q Chambers, William J Riley

{"title":"Coupled model intercomparison project phase 6 (CMIP6) high resolution model intercomparison project (HighResMIP) bias in extreme rainfall drives underestimation of amazonian precipitation","authors":"Robinson Negron-Juarez, Michael Wehner, Maria Assunção F Silva Dias, Paul Ullrich, Jeffrey Q Chambers, William J Riley","doi":"10.1088/2515-7620/ad6ff9","DOIUrl":"https://doi.org/10.1088/2515-7620/ad6ff9","url":null,"abstract":"Extreme rainfall events drive the amount and spatial distribution of rainfall in the Amazon and are a key driver of forest dynamics across the basin. This study investigates how the 3-hourly predictions in the High Resolution Model Intercomparison Project (HighResMIP, a component of the recent Coupled Model Intercomparison Project, CMIP6) represent extreme rainfall events at annual, seasonal, and sub-daily time scales. TRMM 3B42 (Tropical Rainfall Measuring Mission) 3 h data were used as observations. Our results showed that eleven out of seventeen HighResMIP models showed the observed association between rainfall and number of extreme events at the annual and seasonal scales. Two models captured the spatial pattern of number of extreme events at the seasonal and annual scales better (higher correlation) than the other models. None of the models captured the sub-daily timing of extreme rainfall, though some reproduced daily totals. Our results suggest that higher model resolution is a crucial factor for capturing extreme rainfall events in the Amazon, but it might not be the sole factor. Improving the representation of Amazon extreme rainfall events in HighResMIP models can help reduce model rainfall biases and uncertainties and enable more reliable assessments of the water cycle and forest dynamics in the Amazon.","PeriodicalId":48496,"journal":{"name":"Environmental Research Communications","volume":null,"pages":null},"PeriodicalIF":2.9,"publicationDate":"2024-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142214894","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0