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Spatio-Temporal Change of Dispersal Areas of Greater Kudu (Tragelaphus strepsiceros) in Lake Bogoria Landscape, Kenya
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作者 Beatrice Chepkoech Cheserek George Morara Ogendi Paul Mutua Makenzi 《Open Journal of Ecology》 2024年第3期183-198,共16页
Decline in wildlife populations is manifest globally, regionally and locally. A wildlife decline of 68% has been reported in Kenya’s rangelands with Baringo County experiencing more than 85% wildlife loss in the last... Decline in wildlife populations is manifest globally, regionally and locally. A wildlife decline of 68% has been reported in Kenya’s rangelands with Baringo County experiencing more than 85% wildlife loss in the last four decades. Greater Kudu (Tragelaphus strepsiceros) is endemic to Lake Bogoria landscape in Baringo County and constitutes a major tourist attraction for the region necessitating use of its photo on the County’s logo and thus a flagship species. Tourism plays a central role in Baringo County’s economy and is a major source of potential growth and employment creation. The study was carried out to assess spatio-temporal change of dispersal areas of Greater Kudu (GK) in Lake Bogoria landscape in the last four years for enhanced adaptive management and improved livelihoods. GK population distribution primary data collected in December 2022 and secondary data acquired from Lake Bogoria National Game Reserve (LBNGR) for 2019 and 2020 were digitized using in a Geographic Information System (GIS). Measures of dispersion and point pattern analysis (PPA) were used to analyze dispersal of GK population using GIS. Spatio-temporal change of GK dispersal in LBNR was evident thus the null hypothesis was rejected. It is recommended that anthropogenic activities contributing to GK’s habitat degradation be curbed by providing alternative livelihood sources and promoting community adoption of sustainable technologies for improved livelihoods. 展开更多
关键词 spatio-temporal change Dispersal Greater Kudu (Tragelaphus Strepsiceros) Point Pattern Analysis (PPA) GIS
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FIBTNet:Building Change Detection for Remote Sensing Images Using Feature Interactive Bi-Temporal Network
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作者 Jing Wang Tianwen Lin +1 位作者 Chen Zhang Jun Peng 《Computers, Materials & Continua》 SCIE EI 2024年第9期4621-4641,共21页
In this paper,a feature interactive bi-temporal change detection network(FIBTNet)is designed to solve the problem of pseudo change in remote sensing image building change detection.The network improves the accuracy of... In this paper,a feature interactive bi-temporal change detection network(FIBTNet)is designed to solve the problem of pseudo change in remote sensing image building change detection.The network improves the accuracy of change detection through bi-temporal feature interaction.FIBTNet designs a bi-temporal feature exchange architecture(EXA)and a bi-temporal difference extraction architecture(DFA).EXA improves the feature exchange ability of the model encoding process through multiple space,channel or hybrid feature exchange methods,while DFA uses the change residual(CR)module to improve the ability of the model decoding process to extract different features at multiple scales.Additionally,at the junction of encoder and decoder,channel exchange is combined with the CR module to achieve an adaptive channel exchange,which further improves the decision-making performance of model feature fusion.Experimental results on the LEVIR-CD and S2Looking datasets demonstrate that iCDNet achieves superior F1 scores,Intersection over Union(IoU),and Recall compared to mainstream building change detectionmodels,confirming its effectiveness and superiority in the field of remote sensing image change detection. 展开更多
关键词 change detection change residual module feature exchange mechanism feature fusion
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Spatio-temporal distribution of net primary productivity along the northeast China transect and its response to climatic change 被引量:9
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作者 朱文泉 潘耀忠 +1 位作者 刘鑫 王爱玲 《Journal of Forestry Research》 SCIE CAS CSCD 2006年第2期93-98,共6页
An improved Carnegie Ames Stanford Approach model (CASA model) was used to estimate the net primary productivity (NPP) of the Northeast China Transect (NECT) every month from 1982 to 2000. The spatial-temporal d... An improved Carnegie Ames Stanford Approach model (CASA model) was used to estimate the net primary productivity (NPP) of the Northeast China Transect (NECT) every month from 1982 to 2000. The spatial-temporal distribution of NPP along NECT and its response to climatic change were also analyzed. Results showed that the change tendency of NPP spatial distribution in NECT is quite similar to that of precipitation and their spatial correlation coefficient is up to 0.84 (P 〈 0.01). The inter-annual variation of NPP in NECT is mainly affected by the change of the aestival NPP every year, which accounts for 67.6% of the inter-annual increase in NPP and their spatial correlation coefficient is 0.95 (P 〈 0.01). The NPP in NECT is mainly cumulated between May and September, which accounts for 89.8% of the annual NPP. The NPP in summer (June to August) accounts for 65.9% of the annual NPP and is the lowest in winter. Recent climate changes have enhanced plant growth in NECT. The mean NPP increased 14.3% from 1980s to 1990s. The inter-annual linear trend of NPP is 4.6 gC·m^-2·a^-1, and the relative trend is 1.17%, which owns mainly to the increasing temperature. 展开更多
关键词 China Transect Remote sensing Net primary productivity (NPP) Climatic change spatio-temporal distribution
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Spatio-Temporal Changes in the Rice Planting Area and Their Relationship to Climate Change in Northeast China: A Model-Based Analysis 被引量:14
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作者 XIA Tian WU Wen-bin +5 位作者 ZHOU Qing-bo YU Qiang-yi Peter H Verburg YANG Peng LU Zhong-jun TANG Hua-jun 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2014年第7期1575-1585,共11页
Rice is one of the most important grain crops in Northeast China (NEC) and its cultivation is sensitive to climate change. This study aimed to explore the spatio-temporal changes in the NEC rice planting area over t... Rice is one of the most important grain crops in Northeast China (NEC) and its cultivation is sensitive to climate change. This study aimed to explore the spatio-temporal changes in the NEC rice planting area over the period of 1980-2010 and to analyze their relationship to climate change. To do so, the CLUE-S (conversion of land use and its effects at small region extent) model was ifrst updated and used to simulate dynamic changes in the rice planting area in NEC to understand spatio-temporal change trends during three periods: 1980-1990, 1990-2000 and 2000-2010. The changing results in individual periods were then linked to climatic variables to investigate the climatic drivers of these changes. Results showed that the NEC rice planting area expanded quickly and increased by nearly 4.5 times during 1980-2010. The concentration of newly planted rice areas in NEC constantly moved northward and the changes were strongly dependent on latitude. This conifrmed that climate change, increases in temperature in particular, greatly inlfuenced the shift in the rice planting area. The shift in the north limit of the NEC rice planting area generally followed a 1&#176;C isoline migration pattern, but with an obvious time-lag effect. These ifndings can help policy makers and crop producers take proper adaptation measures even when exposed to the global warming situation in NEC. 展开更多
关键词 spatio-temporal change rice planting area climate change Northeast China
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Spatio-Temporal Changes of Soil Salinity in Arid Areas of South Xinjiang Using Electromagnetic Induction 被引量:10
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作者 LI Xiao-ming YANG Jing-song +2 位作者 LIU Mei-xian LIU Guang-ming YU Mei 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2012年第8期1365-1376,共12页
The aim of this paper was to research the spatio-temporal changes in total soluble salt content (TS) in a typical arid region of South Xinjiang, China, where the climate is arid and soil salinization happens easily.... The aim of this paper was to research the spatio-temporal changes in total soluble salt content (TS) in a typical arid region of South Xinjiang, China, where the climate is arid and soil salinization happens easily. The total soluble salt content was interpreted by measurements made in the horizontal mode with EM38 and EM31. The electromagnetic induction (EM) surveys were made three times with the apparent soil electrical conductivity (ECa) measurements taken at 3 873 locations in Nov. 2008, 4 807 locations in Apr. 2009 and 6 324 locations in Nov. 2009, respectively. For interpreting the ECa measurements into total soluble salt content, calibtion sites were needed for EM survey of each time, e.g., 66 sites were selected in Nov. 2008 to measure ECa, and soils-core samples were taken by different depth layers of 0-10, 10-20 and 20-40 cm at the same time. On every time duplicate samples were taken at five sites to allevaite the local-scale variability, and soil temperatures in different layers through the profiles were also measured. Factors including TS, pH, water content, bulk density were analyzed by lab experiments. ECa calibration equations were obtained by linear regression analysis, which indicated that soil salinity was one primary concern to ECa with a determination coefficient of 0.792 in 0-10 cm layer, 0.711 in 10-20 cm layer and 0.544 in 20-40 cm layer, respectively. The maps of spatial distribution were predicted by Kriging interpolation, which showed that the high soil salinity was located near the drainage canal, which validated the trend effect caused by the irrigation canal and the drainage canal. And by comparing the soil salinity in different layers, the soluble salt accumulated to the top soil surface only in the area where the soil salinization was serious, and in the other areas, the soil salinity trended to increase from the top soil surface to 40 cm depth. Temporal changes showed that the soil salinity in November was higher than that in April, and the soil salinization trended to aggravate, especially in the top soil layer of 0-10 cm. 展开更多
关键词 spatio-temporal changes soil salinity South Xinjiang electromagnetic induction (EM) KRIGING
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Histopathological changes in retinas and F-ERG features of streptozotocin-induced diabetic rats treated with ozone 被引量:2
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作者 Ting-Yu Xie Qin Li Xue-Yi Chen 《International Journal of Ophthalmology(English edition)》 SCIE CAS 2016年第6期816-820,共5页
AIM: To study the histopathological changes in the retina and flash electroretinogram (F-ERG) features of ozone-treated streptozotocin (STZ)-induced diabetic rats. METHODS: Seventy male Sprague Dawley rats were ... AIM: To study the histopathological changes in the retina and flash electroretinogram (F-ERG) features of ozone-treated streptozotocin (STZ)-induced diabetic rats. METHODS: Seventy male Sprague Dawley rats were grouped as follows: blank group (GB, n=10), model control group (GM, n=18), ozone group (GOs, n=19), and oxygen group (GO2, n=18). The model was induced by single intraperitoneal injection of STZ. Ozone or oxygen enteroclysm was given twice per week for 4wk. F-ERG and histopathological examinations were performed one month after treatment. RESULTS: Under dark adaption, as compared to GB, the other groups each had differential decreases in the a-wave amplitudes (P〈0.05); the latencies were delayed in GM, GO2, and GO3 rats (P〈0.05). Similar results were observed under light adaption, with the exception that the a-wave of the amplitudes (F=0.28, P〉0.05). There were significant differences in the apoptosis index among the groups (P〈0.05). Under ozone treatment, apoptosis was decreased in GO3 as compared to GM and GO2 . CONCLUSION: Ozone administration alleviates nerve damage and reduces pathology and apoptosis in the retinas of diabetic rats. 展开更多
关键词 diabetic rat retina ozone treatment histopathological changes flash electroretinogram features
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Spatio-temporal changes of underground coal fires during 2008-2016 in Khanh Hoa coal field(North-east of Viet Nam) using Landsat time-series data 被引量:3
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作者 Tuyen Danh VU Thanh Tien NGUYEN 《Journal of Mountain Science》 SCIE CSCD 2018年第12期2703-2720,共18页
Underground coal fires are one of the most common and serious geohazards in most coal producing countries in the world. Monitoring their spatio-temporal changes plays an important role in controlling and preventing th... Underground coal fires are one of the most common and serious geohazards in most coal producing countries in the world. Monitoring their spatio-temporal changes plays an important role in controlling and preventing the effects of coal fires, and their environmental impact. In this study, the spatio-temporal changes of underground coal fires in Khanh Hoa coal field(North-East of Viet Nam) were analyzed using Landsat time-series data during the 2008-2016 period. Based on land surface temperatures retrieved from Landsat thermal data, underground coal fires related to thermal anomalies were identified using the MEDIAN+1.5×IQR(IQR: Interquartile range) threshold technique. The locations of underground coal fires were validated using a coal fire map produced by the field survey data and cross-validated using the daytime ASTER thermal infrared imagery. Based on the fires extracted from seven Landsat thermal imageries, the spatiotemporal changes of underground coal fire areas were analyzed. The results showed that the thermalanomalous zones have been correlated with known coal fires. Cross-validation of coal fires using ASTER TIR data showed a high consistency of 79.3%. The largest coal fire area of 184.6 hectares was detected in 2010, followed by 2014(181.1 hectares) and 2016(178.5 hectares). The smaller coal fire areas were extracted with areas of 133.6 and 152.5 hectares in 2011 and 2009 respectively. Underground coal fires were mainly detected in the northern and southern part, and tend to spread to north-west of the coal field. 展开更多
关键词 UNDERGROUND COAL fires spatio-temporal changeS Khanh Hoa COAL field (Viet Nam) LANDSAT time-series data
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Analysis of Spatio-Temporal Changes of Land Usein Xuzhou City Based on Remote Sensing 被引量:3
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作者 HU Zhao-ling DU Pei-jun GUO Da-zhi 《Journal of China University of Mining and Technology》 EI 2006年第2期151-155,共5页
Based on the satellite remote sensing TM/ETM images of Xuzhou city, basic data about land use of the city from 1994 to 2000 are obtained with the neural network classification module of PCI software, and the dynamic c... Based on the satellite remote sensing TM/ETM images of Xuzhou city, basic data about land use of the city from 1994 to 2000 are obtained with the neural network classification module of PCI software, and the dynamic con- version matrix of land use is thus calculated. The areas of construction land and water body have increased by 1833.93 hm2 and 804.87 hm2, respectively. On the contrary, the area of cropland has decreased by 3207.24 hm2. The area of cropland converted into construction land makes up 26.84%, and that converted into water body amounts for 8.17% of the total area of cropland in 1994. The variation index of land use degree and the dynamic degree index of land use computed are 1.38 and 57.81%, respectively, which demonstrate that land use in Xuzhou is in a development period and the changes are drastic. The frequency index and importance index of the form in which cropland converted into con- struction land are 29.91% and 68.93% respectively. The results indicate that the change is not only widespread in space but a major form of spatial change of land use in the area. 展开更多
关键词 remote sensing image land use spatio-temporal change Xuzhou city
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Spatio-temporal changes of exposure and vulnerability to floods in China 被引量:1
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作者 WANG Yan-Jun GAO Chao +3 位作者 ZHAI Jian-Qing LI Xiu-Cang SU Bu-da HARTMANN Heike 《Advances in Climate Change Research》 SCIE 2014年第4期197-205,共9页
A socio-economic data set on China's historical flood losses for the period 1984--2012 was compiled to analyze the exposed population, economy, and crop area as well as the vulnerabilities of the population and econo... A socio-economic data set on China's historical flood losses for the period 1984--2012 was compiled to analyze the exposed population, economy, and crop area as well as the vulnerabilities of the population and economy to floods. The results revealed that the exposed population was approximately 126 persons km-2 per year when taking China as a whole; in terms of the economy, potential losses due to floods were estimated to be approximately 1.49 million C/W4 km 2 and the crop area exposed to floods covered 153 million hm2 per year. China's total exposure to floods significantly increased over the analysis period. The areas that showed the higher exposure were mainly located along the east coast. The population's vulnerability to floods showed a significantly increasing trend, however, the economic vulnerability showed a decreasing trend. The populations and economies that were most vulnerable to floods were in Hunan, Anhui, Chongqing, Jiangxi, and Hubei provinces. The municipalities of Shanghai, Beijing, and Tianjin showed the lowest vulnerabilities to floods. 展开更多
关键词 EXPOSURE VULNERABILITY Flood disaster spatio-temporal changes China
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Sedimentary Features and Sea-Level Changes Reflected in Drill Holes in the Zhuhai Area
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作者 CHEN Junren WAN Ling 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 1999年第2期216-224,共9页
Abstract Experimental examinations and analyses have been made of the sediments from drill holes in the Zhuhai area, Guangdong Province. The studies show that there occurred four transgressions in this area over the h... Abstract Experimental examinations and analyses have been made of the sediments from drill holes in the Zhuhai area, Guangdong Province. The studies show that there occurred four transgressions in this area over the historical times. The first transgression occurred at 7500 a B.P., with the maxium sea level up to about 1 m above the present level. The second transgression occurred at 5750 a B.P., with the sea level possibly 4 m higher than the present. The third and fourth transgressions took place at 4650 a B.P. and 2600 a B.P. respectively, which lasted for a long time with multiple fluctuations. The fifth transgression is in process. It could be predicted that the sea level at Zhuhai would rise by 15–20 cm in the coming 50 years. 展开更多
关键词 sedimentary features sea-level changes Zhuhai
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MRI Features and Site-specific Factors of Ischemic Changes in White Matter: A Retrospective Study
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作者 You-ping ZHANG Na LIU +5 位作者 Kai-yan LIU Chao PAN Xuan CAI Shi-qi YANG Zhou-ping TANG Sha-bei XU 《Current Medical Science》 SCIE CAS 2018年第2期318-323,共6页
Brain magnetic resonance imaging (MRI) of the elderly often reveals white matter changes (WMCs) with substantial variability across individuals. Our study was designed to explore MRI features and site-specific fac... Brain magnetic resonance imaging (MRI) of the elderly often reveals white matter changes (WMCs) with substantial variability across individuals. Our study was designed to explore MRI features and site-specific factors of ischemic WMCs. Clinical data of consecutive patients diagnosed with ischemic cerebral vascular disease who had undergone brain MRI were collected and analyzed. Multi-logistic regression analysis comparing patients with mild versus severe WMCs was performed to detect independent associations. Analyses of variance (ANOVAs) were used to detect regionally specific differences in lesions. We found that lesion distribution differed significantly across five cerebral areas, with lesions being predominant in the frontal lobe and parieto-occipital area. To explore WMCs risk factors, after adjusting for gender, diabetes mellitus, and hypertension, only age (P〈0.01), creatinine (P=0.01), alkaline phosphatase (ALP) (P=0.01) and low-density lipoprotein cholesterol (LDL-C) (P=0.03) were found to be independently associated with severe WMCs. Age (P〈0.001) was strongly associated with WMCs in the frontal lobe while hypertension was independently related to lesions in the basal ganglia (P=0.048) or infratentorial area (P=0.016). In conclusion, MRI of WMCs showed that ischemic WMCs occurred mostly in the frontal lobe and parieto-occipital area. The infratentorial area was least affected by WMCs. Typically, age-related WMCs were observed in the frontal lobes, while hypertension-related WMCs tended to occur in the basal ganglia and infratentorial area. 展开更多
关键词 white matter changes ischemic cerebral vascular disease MRI features sitespecific factors
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Analysis of spatio-temporal changes in forest biomass in China
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作者 Weiyi Xu Xiaobin Jin +3 位作者 Jing Liu Xuhong Yang Jie Ren Yinkang Zhou 《Journal of Forestry Research》 SCIE CAS CSCD 2022年第1期261-278,共18页
Forests play a central role in the global carbon cycle.China's forests have a high carbon sequestration potential owing to their wide distribution,young age and relatively low carbon density.Forest biomass is an e... Forests play a central role in the global carbon cycle.China's forests have a high carbon sequestration potential owing to their wide distribution,young age and relatively low carbon density.Forest biomass is an essential variable for assessing carbon sequestration capacity,thus determining the spatio-temporal changes of forest biomass is critical to the national carbon budget and to contribute to sustainable forest management.Based on Chinese forest inventory data(1999–2013),this study explored spatial patterns of forest biomass at a grid resolution of 1 km by applying a downscaling method and further analyzed spatiotemporal changes of biomass at different spatial scales.The main findings are:(1)the regression relationship between forest biomass and the associated infuencing factors at a provincial scale can be applied to estimate biomass at a pixel scale by employing a downscaling method;(2)forest biomass had a distinct spatial pattern with the greatest biomass occurring in the major mountain ranges;(3)forest biomass changes had a notable spatial distribution pattern;increase(i.e.,carbon sinks)occurred in east and southeast China,decreases(i.e.,carbon sources)were observed in the northeast to southwest,with the largest biomass losses in the Hengduan Mountains,Southern Hainan and Northern Da Hinggan Mountains;and,(4)forest vegetation functioned as a carbon sink during 1999–2013 with a net increase in biomass of 3.71 Pg. 展开更多
关键词 Forest vegetation biomass Spatial distribution spatio-temporal changes
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Analysis on the Spatio-Temporal Changes of Sustainable Land Use in Tibet
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作者 GU Shixian XU Xia LIU Shuzhen 《Wuhan University Journal of Natural Sciences》 EI CAS 2006年第4期937-944,共8页
By constructing evaluation indicator system of sustainable land use of Tibet from three aspects of ecological environment, economic development, resources and social advancement, this article studies the following con... By constructing evaluation indicator system of sustainable land use of Tibet from three aspects of ecological environment, economic development, resources and social advancement, this article studies the following contents respectively in two dimensions of time and space: the changes of sustainable land use of Tibet in recent 20 years and spatial characteristics of sustainable land use of Tibet in 2002. The following conclusions can be drawn from evaluation results .① With regard to com- prehensive evaluation value of sustainable land use, the trend of Tibet sustainable land use evaluation values from 1983 to 2002 are very close to the comprehensive evaluation values of ecological environment, which is up trend; ② sustainable utilization degree of land use in eastern region of Tibet is much higher than that of western region. ③ the sustainable land use evaluation value of Nyingtri County is the highest, and the counties with relatively higher land sustainable use values include Lhasa, Lhoka, Chamdo. While Nakchu, Ngari, Shigatse counties have the relatively lower evaluation values; ④ By analyzing each evaluation indicator's weight on sustainable land use, it can be concluded that the key limiting factors of sustainable Tibet land resource utilization are land desertification, grassland degradation and low economic level. 展开更多
关键词 spatio-temporal changes sustainable land use ecological environment economic development resources and social advancement
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Spatio-temporal Changes and Associated Uncertainties of CENTURYmodelled SOC for Chinese Upland Soils, 1980-2010
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作者 LIU Xiaoyu ZHAO Yongcun +3 位作者 SHI Xuezheng WANG Shihang FENG Xiang YAN Fang 《Chinese Geographical Science》 SCIE CSCD 2021年第1期126-136,共11页
Detailed information on the spatio-temporal changes of cropland soil organic carbon(SOC) can significantly contribute to the improvement of soil fertility and mitigate climate change. Nonetheless, information and know... Detailed information on the spatio-temporal changes of cropland soil organic carbon(SOC) can significantly contribute to the improvement of soil fertility and mitigate climate change. Nonetheless, information and knowledge on the national scale spatio-temporal changes and the corresponding uncertainties of SOC in Chinese upland soils remain limited. The CENTURY model was used to estimate the SOC storages and their changes in Chinese uplands from 1980 to 2010. With the Monte Carlo method, the uncertainties of CENTURY-modelled SOC dynamics associated with the spatial heterogeneous model inputs were quantified. Results revealed that the SOC storage in Chinese uplands increased from 3.03(1.59 to 4.78) Pg C in 1980 to 3.40(2.39 to 4.62) Pg C in 2010. Increment of SOC storage during this period was 370 Tg C, with an uncertainty interval of –440 to 1110 Tg C. The regional disparities of SOC changes reached a significant level, with considerable SOC accumulation in the Huang-Huai-Hai Plain of China and SOC loss in the northeastern China. The SOC lost from Meadow soils, Black soils and Chernozems was most severe, whilst SOC accumulation in Fluvo-aquic soils, Cinnamon soils and Purplish soils was most significant. In modelling large-scale SOC dynamics, the initial soil properties were major sources of uncertainty. Hence, more detailed information concerning the soil properties must be collected. The SOC stock of Chinese uplands in 2010 was still relatively low, manifesting that recommended agricultural management practices in conjunction with effectively economic and policy incentives to farmers for soil fertility improvement were indispensable for future carbon sequestration in these regions. 展开更多
关键词 soil organic carbon(SOC) CENTURY model uncertainty analysis heterogeneous model input data spatio-temporal change
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Features of temperature changes at Barrow of Arctic in the last 400 a
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作者 王国 张青松 《Chinese Journal of Polar Science》 1998年第1期35-40,共6页
A temperature record from a lake core reveals that it becomes warming at average rate of 0 4 ℃ per century in the past 400 a at Barrow, but it turns cold in the past 200 a. Maximum entropy spectra analysis shows tha... A temperature record from a lake core reveals that it becomes warming at average rate of 0 4 ℃ per century in the past 400 a at Barrow, but it turns cold in the past 200 a. Maximum entropy spectra analysis shows that in the temperature fluctuations there are cycles of 33, 40, 29 a and about 90 a at Barrow. According to statistics and entropy analysis of monthly mean temperature from Barrow Meteorological Observatory in 1921 1994, there are cycles of 4, 6, 14, 16 months and 3, 4, 7, 10 a in the recent temperature change. 展开更多
关键词 ARCTIC BARROW temperature change entropy spectra feature.
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Effect of geomorphologic features and climate change on vegetation distribution in the arid hot valleys of Jinsha River,Southwest China
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作者 ZHOU Yang YI Yu-jun +3 位作者 LIU Hong-xi TANG Cai-hong ZHU Yu-long ZHANG Shang-hong 《Journal of Mountain Science》 SCIE CSCD 2022年第10期2874-2885,共12页
Rapid change of climate in vertical and considerable geomorphologic features form a typical diversity and distribution of biota in mountain ecosystems,i.e.,the subalpine forest zone(SFZ),the valley savanna zone(VSZ),a... Rapid change of climate in vertical and considerable geomorphologic features form a typical diversity and distribution of biota in mountain ecosystems,i.e.,the subalpine forest zone(SFZ),the valley savanna zone(VSZ),and the transition zone between them.The arid hot valley in the middle and lower reaches of Jinsha River,China represents a well target area to study distribution and the driving factors in these typical mountain ecosystems.Therefore,this study selects four sub-sample areas in the arid-hot valley to explore the distinctive changes of vegetation during 1990 to 2020,and their driving factors in the three different vegetation zones on spatiotemporal scales.On the spatial scale,the Moran’s index was applied to identify the transition zone between the SFZ and the VSZ.Results show that the VSZ at low altitudes(less than 600-1000 m from the valley bottom)is mainly affected by geomorphologic features,especially the slope aspect.With increase in altitude,the climate factors(e.g.,humidity,temperature,etc.)play a more significant role in the development of the SFZ,while the effect of geomorphologic features gradually weakens.On the time scale,The SFZ at higher altitudes experienced more rapid changes in temperature(temperature increase of 1.41°C over the last 60 years)than the VSZ at lower altitudes(temperature increase of 0.172°C over the past 60 years).It caused the forest cover increase faster than that of savanna grassland.Humidity and heat conditions are altered by topography and climate conditions,which shapes the development and physiology of plants as they adapt to the different climatic zones.Furthermore,according to the driving factors(geomorphologic and climate factors)of vegetation distribution found in this study,it suggests that suitable tree species should be planted in the transition zone to evolve into the forest zone and making the forest zone to recover from high to low altitudes gradually. 展开更多
关键词 Mountain vegetation distribution Subalpine forest zone Valley savanna zone Geomorphologic features Climate change
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Changes in the Features of Major Contradictions
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作者 Lu Zhongwei Wang Zaibang Ji Zhiye Fu Mengzi Feng Zhongping Yang Bojiang Dao Shulin Yang Mingjie Lin Limin Su Jingxiang He Xiquan 《Contemporary International Relations》 2003年第2期1-14,共14页
Immediately after humanity entered the new century,the worldseems somewhat a bit turbulent because of the following events.First are the September 11 events,which were followed by U.S.militaryattacks against Afghanist... Immediately after humanity entered the new century,the worldseems somewhat a bit turbulent because of the following events.First are the September 11 events,which were followed by U.S.militaryattacks against Afghanistan.Last year witnessed the continuity of Arab-Israel conflicts in the Middle East,and at the very beginning of the newyear,the United States dispatched warships to the Persian Gulf for a“war to topple the Saddam regime”.The Democratic People’s Republicof Korea(DPRK)suddenly declared that it has decided to withdraw fromthe Nuclear Non-proliferation Treaty just after Iraq stated that it wasdetermined to resist the United States.Whither the world in the new year?This is a question that all of the academic circles on international relationsare trying to answer.To this end,on January 9,2002,we speciallyinvited Lu Zhongwei,Research Professor and President of China Instituteof Contemporary International Relations and some other experts oninternational relations from the institute to hold a symposium with the theme“Prospect on World Trend 2003.”Now we present their discussions as anew-year gift to our readers who are always in support of our journal.Wehope this would do a bit for their mastery of international situation. 展开更多
关键词 of on in changes in the features of Major Contradictions that HAVE for BE from
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Unsupervised change detection of man-made objects using coherent and incoherent features of multi-temporal SAR images
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作者 FENG Hao WU Jianzhong +1 位作者 ZHANG Lu LIAO Mingsheng 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2022年第4期896-906,共11页
Constrained by complex imaging mechanism and extraordinary visual appearance,change detection with synthetic aperture radar(SAR)images has been a difficult research topic,especially in urban areas.Although existing st... Constrained by complex imaging mechanism and extraordinary visual appearance,change detection with synthetic aperture radar(SAR)images has been a difficult research topic,especially in urban areas.Although existing studies have extended from bi-temporal data pair to multi-temporal datasets to derive more plentiful information,there are still two problems to be solved in practical applications.First,change indicators constructed from incoherent feature only cannot characterize the change objects accurately.Second,the results of pixel-level methods are usually presented in the form of the noisy binary map,making the spatial change not intuitive and the temporal change of a single pixel meaningless.In this study,we propose an unsupervised man-made objects change detection framework using both coherent and incoherent features derived from multi-temporal SAR images.The coefficients of variation in timeseries incoherent features and the man-made object index(MOI)defined with coherent features are first combined to identify the initial change pixels.Afterwards,an improved spatiotemporal clustering algorithm is developed based on density-based spatial clustering of applications with noise(DBSCAN)and dynamic time warping(DTW),which can transform the initial results into noiseless object-level patches,and take the cluster center as a representative of the man-made object to determine the change pattern of each patch.An experiment with a stack of 10 TerraSAR-X images in Stripmap mode demonstrated that this method is effective in urban scenes and has the potential applicability to wide area change detection. 展开更多
关键词 change detection multi-temporal synthetic aperture radar(SAR)data coherent and incoherent features CLUSTERING
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Deep Facial Emotion Recognition Using Local Features Based on Facial Landmarks for Security System
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作者 Youngeun An Jimin Lee +1 位作者 Eunsang Bak Sungbum Pan 《Computers, Materials & Continua》 SCIE EI 2023年第8期1817-1832,共16页
Emotion recognition based on facial expressions is one of the most critical elements of human-machine interfaces.Most conventional methods for emotion recognition using facial expressions use the entire facial image t... Emotion recognition based on facial expressions is one of the most critical elements of human-machine interfaces.Most conventional methods for emotion recognition using facial expressions use the entire facial image to extract features and then recognize specific emotions through a pre-trained model.In contrast,this paper proposes a novel feature vector extraction method using the Euclidean distance between the landmarks changing their positions according to facial expressions,especially around the eyes,eyebrows,nose,andmouth.Then,we apply a newclassifier using an ensemble network to increase emotion recognition accuracy.The emotion recognition performance was compared with the conventional algorithms using public databases.The results indicated that the proposed method achieved higher accuracy than the traditional based on facial expressions for emotion recognition.In particular,our experiments with the FER2013 database show that our proposed method is robust to lighting conditions and backgrounds,with an average of 25% higher performance than previous studies.Consequently,the proposed method is expected to recognize facial expressions,especially fear and anger,to help prevent severe accidents by detecting security-related or dangerous actions in advance. 展开更多
关键词 Facial emotion recognition landmark-based feature extraction ensemble network robustness to the changes in illumination and background dangerous situation detection accident prevention
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Geophysical Features of the Ore-Controlling Fault in the Chang'an Gold Deposit, Southern Yunnan Province 被引量:1
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作者 LI Hua ASKAR +4 位作者 ZHOU Yunman ZHANG Wei WU Wenxian ZHOU Yimin ZHOU Kuiwu 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2015年第5期1771-1772,共2页
The Ailao Mountain is one of the most important metallogenic belts ofpolymetallic deposits in the Sanjiang region, southwestern China. Located in the southern segment of this metallogenic belt, the newly-discovered Ch... The Ailao Mountain is one of the most important metallogenic belts ofpolymetallic deposits in the Sanjiang region, southwestern China. Located in the southern segment of this metallogenic belt, the newly-discovered Chang'an gold deposit is large in scale (Fig. 1A), and has attracted much attention among geologists. The ore-hosted rocks in the district include the Late Ordovician Xiangyang Fm. sandstone and clastic rocks and the Early Silurian Kanglang Fm. dolomite. Affected by the multistage tectonic activities, stocks and dykes of lamprophyre, dolerite, syenite porphyry and orthoclasite are widely exposed, and the orebodies are in symbiosis with or crosscut the dyke rocks. 展开更多
关键词 GOLD Southern Yunnan Province Geophysical features of the Ore-Controlling Fault in the chang’an Gold Deposit
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