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Uncertainties of landslide susceptibility prediction:influences of different study area scales and mapping unit scales
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作者 Faming Huang Yu Cao +4 位作者 Wenbin Li Filippo Catani Guquan Song Jinsong Huang Changshi Yu 《International Journal of Coal Science & Technology》 EI CAS CSCD 2024年第2期143-172,共30页
This study aims to investigate the effects of different mapping unit scales and study area scales on the uncertainty rules of landslide susceptibility prediction(LSP).To illustrate various study area scales,Ganzhou Ci... This study aims to investigate the effects of different mapping unit scales and study area scales on the uncertainty rules of landslide susceptibility prediction(LSP).To illustrate various study area scales,Ganzhou City in China,its eastern region(Ganzhou East),and Ruijin County in Ganzhou East were chosen.Different mapping unit scales are represented by grid units with spatial resolution of 30 and 60 m,as well as slope units that were extracted by multi-scale segmentation method.The 3855 landslide locations and 21 typical environmental factors in Ganzhou City are first determined to create spatial datasets with input-outputs.Then,landslide susceptibility maps(LSMs)of Ganzhou City,Ganzhou East and Ruijin County are pro-duced using a support vector machine(SVM)and random forest(RF),respectively.The LSMs of the above three regions are then extracted by mask from the LSM of Ganzhou City,along with the LSMs of Ruijin County from Ganzhou East.Additionally,LSMs of Ruijin at various mapping unit scales are generated in accordance.Accuracy and landslide suscepti-bility indexes(LSIs)distribution are used to express LSP uncertainties.The LSP uncertainties under grid units significantly decrease as study area scales decrease from Ganzhou City,Ganzhou East to Ruijin County,whereas those under slope units are less affected by study area scales.Of course,attentions should also be paid to the broader representativeness of large study areas.The LSP accuracy of slope units increases by about 6%–10%compared with those under grid units with 30 m and 60 m resolution in the same study area's scale.The significance of environmental factors exhibits an averaging trend as study area scale increases from small to large.The importance of environmental factors varies greatly with the 60 m grid unit,but it tends to be consistent to some extent in the 30 m grid unit and the slope unit. 展开更多
关键词 Landslide susceptibility prediction Uncertainty analysis Study areas scales Mapping unit scales Slope units Random forest
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Simulation of leaf area index and biomass at landscape scale 被引量:7
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作者 ZHANGNa YUGuirui +1 位作者 YUZhenliang ZHAOShidong 《Journal of Geographical Sciences》 SCIE CSCD 2003年第2期139-152,共14页
The method for simulating the temporal and spatial distribution patterns of leaf area index (LAI) and biomass at landscape scale using remote sensing images and surface data was discussed in this paper. The procedure... The method for simulating the temporal and spatial distribution patterns of leaf area index (LAI) and biomass at landscape scale using remote sensing images and surface data was discussed in this paper. The procedure was: (1) annual maximum normalized difference vegetation index (NDVI) over the landscape was calculated from TM images; (2) the relationship model between NDVI and LAI was built and annual maximum LAI over the landscape was simulated; (3) the relationship models between LAI and biomass were built and annual branch, stem, root and maximum leaf biomass over the landscape were simulated; (4) spatial distribution patterns of leaf biomass and LAI in different periods all the year round were obtained. The simulation was based on spatial analysis module GRID in ArcInfo software. The method is also a kind of scaling method from patch scale to landscape scale. A case study of Changbai Mountain Nature Reserve was dissertated. Analysis and primary validation were carried out to the simulated LAI and biomass for the major vegetation types in the Changbai Mountain in 1995. 展开更多
关键词 landscape scale leaf area index BIOMASS remote sensing field measurement CLC number:Q948.2 TP79
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Evaluation of Rainwater Harvesting Methods and Structures Using Analytical Hierarchy Process for a Large Scale Industrial Area 被引量:1
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作者 V. JOTHIPRAKASH Mandar V. SATHE 《Journal of Water Resource and Protection》 2009年第6期427-438,共12页
In India, with ever increasing population and stress on natural resources, especially water, rejuvenation of rainwater harvesting (RWH) technique which was forgotten over the days is becoming very essential. Large num... In India, with ever increasing population and stress on natural resources, especially water, rejuvenation of rainwater harvesting (RWH) technique which was forgotten over the days is becoming very essential. Large number of RWH methods that are available in the literature are demand specific and site specific, since RWH system depends on the topography, land use, land cover, rainfall and demand pattern. Thus for each and every case, a detailed evaluation of RWH structures is required for implementation, including the analy-sis of hydrology, topography and other aspects like site availability and economics, however a common methodology could be evolved. The present study was aimed at evaluation of various RWH techniques in order to identify the most appropriate technique suitable for a large scale industrial area to meet its daily wa-ter demand. An attempt is made to determine the volume of water to be stored using mass balance method, Ripple diagram method, analytical method, and sequent peak algorithm method. Based on various satisfying criteria, analytical hierarchy process (AHP) is employed to determine the most appropriate type of RWH method and required number of RWH structures in the study area. If economy alone is considered along with hydrological and site specific parameters, recharging the aquifer has resulted as a better choice. However other criteria namely risk, satisfaction in obtaining required volume of water for immediate utilization etc. has resulted in opting for concrete storage structures method. From the results it is found that AHP, if used with all possible criteria can result in a better tool for evaluation of RWH methods and structures. This RWH structures not only meets the demand but saves transportation cost of water and reduces the dependability of the industry on irrigation reservoir. Besides monetary benefits it is hoped that the micro environment inside the industry will improve due to the cooling effect of the stored water. 展开更多
关键词 RAIN Water HARVESTING ANALYTICAL HIERARCHY Process Large scale Industrial area AQUIFER
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Recommendations for Large-scale Farmland Operation in Hilly Areas Based on Long Tail Theory
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作者 Changsheng QIU Dingxiang LIU 《Asian Agricultural Research》 2014年第8期53-56,共4页
At the background of urban and rural integration,this paper analyzed and discussed factors restricting large-scale farmland operation in China's hilly areas from the qualitative perspective. It recognized large-sc... At the background of urban and rural integration,this paper analyzed and discussed factors restricting large-scale farmland operation in China's hilly areas from the qualitative perspective. It recognized large-scale farmland operation on the basis of the long tail theory. Finally,it came up with recommendations for developing large-scale farmland operation in hilly areas. 展开更多
关键词 URBAN and RURAL INTEGRATION HILLY areas Large-scal
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Multi-scale wavelet separation of aeromag-netic anomaly and study of faults in Beijing area
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作者 张先 赵丽 +1 位作者 刘天佑 杨宇山 《Acta Seismologica Sinica(English Edition)》 EI CSCD 2006年第5期542-551,共10页
In this paper, through a multi-scale separation of the aeromagnetic anomaly by wavelet transform technique, we reprocessed the aeromagnetic data collected 20 years ago in Beijing area and analyzed the aeromagnetic ano... In this paper, through a multi-scale separation of the aeromagnetic anomaly by wavelet transform technique, we reprocessed the aeromagnetic data collected 20 years ago in Beijing area and analyzed the aeromagnetic anomaly qualitatively, integrating geological structure features in the area. In particular, we studied the spatial distributions of the two main faults called Shunyi-Liangxiang fault and Banqiao-Babaoshan-Tongxian fault, which have cut and gone through the central Beijing area striking in NE and EW directions, respectively. The influences of these two faults on the earthquakes have also been discussed briefly. 展开更多
关键词 Beijing area aeromagnetic anomaly multi-scale separation fault analysis
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Analysis on the Meso-scale Characteristics of a Hail Process in Linyi Area
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作者 LIU Ying-jie CAO Xing-feng +2 位作者 ZHU Yi-qing WANG Qing-hua LI Bing-wen 《Meteorological and Environmental Research》 CAS 2011年第6期41-45,50,共6页
[Objective] The research aimed to study the meso-scale characteristics of a hail process in Linyi area. [Method] By comprehensively using MICAPS conventional observation data, automatic encryption ground station, MM5 ... [Objective] The research aimed to study the meso-scale characteristics of a hail process in Linyi area. [Method] By comprehensively using MICAPS conventional observation data, automatic encryption ground station, MM5 model product and Doppler weather radar data, a strong convective hail weather process which happened in Shandong Peninsula and southeast of Shandong on May 30, 2010 was analyzed. The circulation background and physical mechanism of strong convection weather occurrence, the features of meso- and micro-scale systems were discussed. Some occurrence and development rules of such weather were found. [Result] The strong convective weather was mainly affected by the cold vortex and translot. The high-altitude northwest airflow, low-level southwest airflow, dry and cold air at the high layer, warm and wet air at the low layer, forward-tilting trough caused the strong convective weather. The radar echo analysis showed that the radar echo in the process belonged to the typical multi-monomer windstorm echo, and the strong echo zone was in the forefront of echo. When the convection development was the strongest, the echo intensity reached 65 dBz, and the echo top height surpassed 11 km. As the development of windstorm monomer, the big-value zone of vertical liquid water content product had the jumping formation and disappearance. Moreover, there was obvious weak echo zone. The windstorm monomer moved to the southeast direction as the precipitation system. In the right front of monomer moving direction, there was hook echo feature. The evolution characteristics of radial speed field at the different elevation angles before and after the hail weather occurrence were analyzed. It was found that the radial speed field had some premonitory variations before the hail weather occurrence. Doppler radar product was used to improve the initial field of MM5 model, which could improve the forecast effect in the certain degree and the accuracy of short-time forecast and nowcasting. [Conclusion] The research accumulated the experience for the short-term forecast and nowcasting work of strong convective weather in future. 展开更多
关键词 HAIL Strong convective weather Meso-scale characteristic Linyi area China
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宁南黄土区中庄小流域土壤密度坡面变化及尺度效应
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作者 韩新生 许浩 +5 位作者 刘广全 安钰 董立国 王月玲 万海霞 郭永忠 《水土保持研究》 北大核心 2025年第2期72-82,共11页
[目的]分析土壤密度在坡面上的变化特征及尺度效应,探讨土壤密度坡面尺度转换路径,为精准监测土壤密度、科学评价土壤功能、指导土壤资源管理提供理论依据。[方法]在宁夏南部半干旱黄土丘陵区中庄小流域,选择3个退耕还林还草后的典型坡... [目的]分析土壤密度在坡面上的变化特征及尺度效应,探讨土壤密度坡面尺度转换路径,为精准监测土壤密度、科学评价土壤功能、指导土壤资源管理提供理论依据。[方法]在宁夏南部半干旱黄土丘陵区中庄小流域,选择3个退耕还林还草后的典型坡面,按坡位从上至下设置了5个样地,调查各样地的植被类型、土地利用、立地条件等,采用环刀法分层测定了200 cm深度的土壤密度。[结果]在东坡、西坡、南坡,土壤密度随土层加深基本表现为线性增加,土层每加深10 cm土壤密度平均增加0.0062,0.0036,0.0075 g/cm^(3),其原因为植被根系、土壤有机质、压实作用的土层差异。在0—200 cm土层,东坡和南坡土壤密度坡面均值均为1.22 g/cm^(3),低于西坡(1.26 g/cm^(3))。3个坡面土壤密度的坡面变化存在差异,东坡、西坡、南坡沿坡变化表现为逐渐增加或先增后减、先升后降、先降后升,整体上为坡面下部大于上部,主要原因包括植被类型、土地利用、人类活动、恢复年限等坡面差异。以离坡顶水平距离增加100 m土壤密度坡面滑动平均值的变化量评价坡面尺度效应,0—200 cm土层的平均土壤密度坡面尺度效应在东坡为0.032(g/cm^(3))/100 m,在西坡为0.024(g/cm^(3))/100 m(离坡顶0—250 m)和-0.007(g/cm^(3))/100 m(离坡顶250—329 m),在南部为-0.011(g/cm^(3))/100 m(离坡顶0—140 m)和0.018(g/cm^(3))/100 m(离坡顶140—368 m)。构建3个坡面不同坡位样地各土层的土壤密度与坡面均值的比值随离坡顶水平距离增加而变化的关系式(R2>0.80,p<0.0001),且基于拟合关系式预测的土壤密度坡面均值的相对误差均小于2.5%,藉此可由任一坡位样地土壤密度测定值准确便捷地估算坡面均值。[结论]半干旱黄土区土壤密度坡面变化和坡位差异明显,且植被类型、人为干扰、土地利用等对土壤密度坡面分布格局影响较大,未来应加强主要作用因子对土壤密度坡面变化及尺度效应的贡献研究。 展开更多
关键词 土壤密度 坡面变化 尺度效应 植被类型 半干旱黄土区
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趋同与异质:专业学位博士毕业生就业结构研究--基于全国30162条专业学位博士毕业生数据的实证分析
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作者 罗洪川 张学敏 甘雪岩 《研究生教育研究》 北大核心 2025年第1期97-108,共12页
基于全国30162条专业学位博士毕业生数据,从趋同性和异质性两个维度探讨其就业规模、结构及时空分布样态。研究发现,在就业规模方面,专业学位博士毕业生具有高度趋同性,体现在高就业率(99.02%)和低待业率,且不同专业学位类别的博士生就... 基于全国30162条专业学位博士毕业生数据,从趋同性和异质性两个维度探讨其就业规模、结构及时空分布样态。研究发现,在就业规模方面,专业学位博士毕业生具有高度趋同性,体现在高就业率(99.02%)和低待业率,且不同专业学位类别的博士生就业率均较高。在就业结构方面,因专业学位类别培养目标不同而具有显著异质性,具体体现在就业单位选择异质性、工作性质异质性以及地区分布异质性三个方面。在就业单位选择方面,医学类专业学位博士倾向于选择医疗卫生单位就业,教育博士倾向于选择高等学校就业,工程博士倾向于选择企业就业。在就业工作性质方面,教育博士及工程博士倾向于从事管理工作,医学类专业学位博士倾向于从事教育与(或)科研工作。在就业时空分布方面,人力资本积累地区、高质量经济发展地区的人才供给能力与吸引力显著。基于此,提出教育管理部门、研究生培养单位、就业管理部门及企业应紧密结合国家急需及经济社会发展需求,积极设置开展相关专业学位类别研究生教育并稳步扩大专业学位博士生培养规模。在产教融合和科教融汇的协同育人机制下,致力于培养理论指导实践、实践融合理论的复合型专业学位博士生。 展开更多
关键词 专业学位 博士毕业生 就业结构 就业规模 就业地区
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黄河源实际蒸发和径流变化多时间尺度归因分析
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作者 曹振江 姬广兴 +5 位作者 杨瑞婷 王雨欣 李凡 张亚丽 陈伟强 黄珺嫦 《水土保持研究》 北大核心 2025年第1期209-217,共9页
[目的]全面分析黄河源区变化环境下水文要素(实际蒸发和径流)变化的主要影响因素,为黄河源区水文循环机理研究和生态环境保护提供参考依据。[方法]基于黄河源区1967-2020年的水文气象数据,使用Mann-Kendall趋势检验法在年、季和月时间... [目的]全面分析黄河源区变化环境下水文要素(实际蒸发和径流)变化的主要影响因素,为黄河源区水文循环机理研究和生态环境保护提供参考依据。[方法]基于黄河源区1967-2020年的水文气象数据,使用Mann-Kendall趋势检验法在年、季和月时间尺度上分析黄河源区实际蒸发和径流的变化特征,采用ABCD水文模型和月尺度Budyko模型在多时间尺度上定量分离出人类活动和气候变化对黄河源区实际蒸发和径流变化的贡献率。[结果](1)1967-2020年黄河源区实际蒸发量在年、季和月时间尺度上都表现为显著增加的趋势;径流在年尺度、旱季、8月、9月表现为不显著减少趋势,在雨季和7月表现为不显著增加趋势。(2)在年尺度、旱季、8月和9月,气候变化对流域实际蒸发的影响较大,其对实际蒸发量变化的贡献率分别为59.61%,108.43%,50.71%,58.17%;在雨季和7月,人类活动对流域实际蒸发的影响较大,其贡献率为62.38%和53.34%。(3)无论是在年尺度、季尺度还是7月、8月、9月,都表现为气候变化对流域径流变化的贡献率较大,贡献率分别为55.58%,56.23%,59.92%,68.70%,51.51%和87.03%。[结论]黄河源区不同时间尺度实际蒸发和径流变化多受气候变化影响较大,但是气候因素和人类活动对它们的贡献率相差较小,未来仍应注重人类活动影响的加剧。 展开更多
关键词 黄河源区 实际蒸发 径流 多时间尺度 趋势分析 ABCD水文模型 月尺度Budyko模型
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大比例尺综合物化探测量在浅覆盖区脉状金矿中的找矿实践——以胶东东部乳山于家圈金矿为例
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作者 李秀章 刘晨成 +5 位作者 邱成贵 胡雷 于露 王宁 王润生 姚铮 《地质与勘探》 北大核心 2025年第1期54-63,共10页
胶东是全球三大金矿集区之一和中国最重要的黄金资源基地,脉状金矿床在胶东广泛分布。胶东东部第四系覆盖层薄但分布广泛,且植被发育,导致地表找矿标志不明显,传统单一的找矿方法对脉状金矿识别难度较大,加之地质勘查程度不断提高,导致... 胶东是全球三大金矿集区之一和中国最重要的黄金资源基地,脉状金矿床在胶东广泛分布。胶东东部第四系覆盖层薄但分布广泛,且植被发育,导致地表找矿标志不明显,传统单一的找矿方法对脉状金矿识别难度较大,加之地质勘查程度不断提高,导致该区脉状金矿找矿难度较大。位于胶东东部浅覆盖区的乳山于家圈地区发育1处以金为主的水系沉积物综合异常,该异常强度高,规模较大,浓集中心明显,元素套合好,显示出良好的找矿潜力。本次利用1∶1万地物(激电中梯)化(土壤)综合剖面对对该异常进行了查证,发现6条金矿化蚀变带,快速查明了引起异常的原因,圈定了找矿靶区;利用槽探和钻探工程对该异常及矿化蚀变带进行了揭露和控制,发现了山东省乳山市于家圈金矿床,取得了良好的找矿效果,证明了大比例尺综合物化探测量在胶东东部浅覆盖区寻找脉状金矿的有效性。 展开更多
关键词 大比例尺综合物化探测量 浅覆盖区 脉状金矿 于家圈 乳山 胶东东部
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Sap-flow measurement and scale transferring from sample trees to entire forest stand of Populus euphratica in desert riparian forest in extreme arid region 被引量:2
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作者 JianHua Si 1, Qi Feng 1, HaiYang Xi 1, ZongQiang Chang 1, YongHong Su 1, Kai Zhang 1,2 1. Cold and Arid Regions Environmental and Engineering Research Institute, Chinese Academy of Sciences, Lanzhou, Gansu 730000, China. 2. Institute of Arid Meteorology, China Meteorological Administration, Lanzhou, Gansu 730020, China. 《Research in Cold and Arid Regions》 2009年第3期258-266,共9页
Understanding how the transpiration of this vegetation type responds to environmental stress is important for determining the wa-ter-balance dynamics of the riparian ecosystem threatened by groundwater depletion. Tran... Understanding how the transpiration of this vegetation type responds to environmental stress is important for determining the wa-ter-balance dynamics of the riparian ecosystem threatened by groundwater depletion. Transpiration and sap flow were measured using the heat-pulse technique. The results were then projected up to the stand level to investigate the stand’s water-use in relation to climate forcing in the desert riparian forest in an extreme arid region. This study took place from April through October 2003 and from May through October 2004. The experimental site was selected in the Populus euphratica Forest Reserve (101o10' E, 41o59' N) in Ejina county, in the lower Heihe River basin, China. The sapwood area was used as a scalar to extrapolate the stand-water consumption from the whole trees’ water consumption measured by the heat-pulse velocity recorder (HPVR). Scale transferring from a series of individual trees to a stand was done according to the existing natural variations between trees under given environmental conditions. The application of the biometric parameters available from individual tree and stand levels was proved suitable for this purpose. A significant correlation between the sapwood area and tree diameter at breast height (DBH) was found. The prediction model is well fitted by the power model. On the basis of the prediction model, the sapwood area can be cal-culated by DBH. The sap-flow density can then be used to extrapolate the stand-water use by means of a series of mathematical models. 展开更多
关键词 sap flow heat-pulse technique sapwood area scale transferring extreme arid region Populus euphratica
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Exploring landslide erosion volume-area scaling relationships by slip depth using changes in DTMs for basin sediment volume estimation 被引量:1
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作者 CHEN Su-chin CHEN Chien-yuan HUANG Wen-yan 《Journal of Mountain Science》 SCIE CSCD 2019年第3期581-594,共14页
Landslides produce large quantities of sediment deposits and reduce reservoir life. This study investigated landslides at the Shihmen Reservoir basin in Taiwan that were induced by Typhoon Sinlaku and Typhoon Jangmi i... Landslides produce large quantities of sediment deposits and reduce reservoir life. This study investigated landslides at the Shihmen Reservoir basin in Taiwan that were induced by Typhoon Sinlaku and Typhoon Jangmi in 2008. We formulate scaling relationships between landslide erosion volume and area and conclude that sediment budget can be estimated based on the easier-todetermine landslide erosion area. The methodologies applied for the investigation were geomorphological analysis through 5 m × 5 m digital terrain models(DTMs) of the basin created before and after the landslide events and spatial analysis through a geographic information system. The erosion area and volume of landslides were measured through the subtraction of DTMs produced before and after the events. Statistical analysis revealed that the landslide erosion frequency–magnitude distribution exhibited power-law behaviors with a scaling exponent of 2.15 for the frequency–area distribution and 1.66 for the frequency–volume distribution. This paper proposes different scaling relationships for different moving depths, and landslide erosion volumes were estimated on the basis of depth; thus, landslides of different scales can be distinguished to avoid errors in volume estimation. Two different scaling exponents are proposed: 1.21 for landslide erosions with depths of less than 2 m and 1.01 for landslide erosions with depths of more than 2 m. The proposed scaling relationships are practical for landslide erosion volume estimation by different depths according to the landslide area, and they can provide preliminary results for sediment budget planning in a reservoir basin. 展开更多
关键词 LANDSLIDE Volume-area scaling relationship POWER-LAW SELF-SIMILARITY GIS LANDSLIDE frequency-area distribution
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Grey-scale sonography and sonoelastography for diagnosing carpal tunnel syndrome 被引量:5
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作者 Hideaki Miyamoto Yutaka Morizaki +1 位作者 Takahiro Kashiyama Sakae Tanaka 《World Journal of Radiology》 CAS 2016年第3期281-287,共7页
Carpal tunnel syndrome(CTS) is a common peripheral entrapment neuropathy of the median nerve at wrist level, and is thought to be caused by compression of the median nerve in the carpal tunnel. There is no standard qu... Carpal tunnel syndrome(CTS) is a common peripheral entrapment neuropathy of the median nerve at wrist level, and is thought to be caused by compression of the median nerve in the carpal tunnel. There is no standard quantitative reference for the diagnosis of CTS. Greyscale sonography and sonoelastography(SEL) have been used as diagnostic tools. The most commonly agreed findings in grey-scale sonography for the diagnosis of CTS is enlargement of the median nerve cross-sectional area(CSA). Several authors have assessed additional parameters. "Delta CSA" is the difference between the proximal median nerve CSA at the pronator quadratus and the maximal CSA within the carpal tunnel. The "CSA ratio" is the ratio of CSA in the carpal tunnel to the CSA at the mid forearm. These additional parameters showed better diagnostic accuracy than CSA measurement alone. Recently, a number of studies have investigated the elasticity of the median nerve using SEL, and have shown that this also has diagnostic value, as it was significantly stiffer in CTS patients compared to healthy volunteers. In this review, we summarize the usefulness of grey-scale sonography and SEL in diagnosing CTS. 展开更多
关键词 CARPAL tunnel syndrome CROSS-SECTIONAL area GRAY-scale SONOGRAPHY Diagnosis MEDIAN nerve SONOELASTOGRAPHY Elasticity
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Three Types of Spatial Function Zoning in Key Ecological Function Areas Based on Ecological and Economic Coordinated Development: A Case Study of Tacheng Basin, China 被引量:3
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作者 WANG Guiling YANG Degang +2 位作者 XIA Fuqiang ZHONG Ruisen XIONG Chuanhe 《Chinese Geographical Science》 SCIE CSCD 2019年第4期689-699,共11页
Three types of spatial function zoning is an effective measure for regional environmental protection and orderly development.For ecological and economic coordinated development, spatial function zones should be divide... Three types of spatial function zoning is an effective measure for regional environmental protection and orderly development.For ecological and economic coordinated development, spatial function zones should be divided scientifically to clear its direction of development and protection. Therefore, based on ecological constraints, a beneficial discussion would be about the key ecological function areas adopting the concept of ecological protection restriction and supporting socioeconomic development for spatial function zoning. In this paper, the researchers, taking Tacheng Basin, Xinjiang of China as an example, choose township as basic research unit and set up an evaluation index system from three aspects, namely, ecological protection suitability, agricultural production suitability, and urban development suitability, which are analyzed by using spatial analysis functions and exclusive matrix method. The results showed that: 1) This paper formed a set of multilevel evaluation index systems for three types of spatial function zoning of the key ecological function areas based on a novel perspective by scientifically dividing Tacheng Basin into ecological space, agricultural space, and urban space,which realized the integration and scientific orientation for spatial function at the township scale. 2) Under the guidance of three types of spatial pattern, the functional orientation and suggestions of development and protection was clearly defined for ecological protection zones,ecological economic zones, agricultural production zones, and urban development zones. 3) A new idea of space governance is provided to promote the coordinated and sustainable development between ecology and economy, which can break the traditional mode of thinking about regional economic development, and offers a scientific basis and reference for macro decision-making. 展开更多
关键词 KEY ecological FUNCTION areas township scale SPATIAL FUNCTION ZONING mutual EXCLUSION matrix method coordination of ECOLOGY and development Tacheng Basin China
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The Multi-Scale Numerical Modeling System for Research on the Relationship between Urban Planning and Meteorological Environment 被引量:37
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作者 房小怡 蒋维楣 +7 位作者 苗世光 张宁 徐敏 季崇萍 陈鲜艳 魏建民 王志华 王晓云 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2004年第1期103-112,共10页
Considering the urban characteristics, a customized multi-scale numerical modeling system is established to simulate the urban meteorological environment. The system mainly involves three spatial scales: the urban sca... Considering the urban characteristics, a customized multi-scale numerical modeling system is established to simulate the urban meteorological environment. The system mainly involves three spatial scales: the urban scale, urban sub-domain scale, and single to few buildings scale. In it, different underlying surface types are employed, the building drag factor is used to replace its roughness in the influence on the urban wind field, the effects of building distribution, azimuth and screening of shortwave radiation are added, and the influence of anthropogenic heating is also taken into account. All the numerical tests indicate that the simulated results are reasonably in agreement with the observational data, so the system can be used to simulate the urban meteorological environment. Making use of it, the characteristics of the meteorological environment from the urban to urban sub-domain scales, even the among-buildings scale, can be recognized. As long as the urban planning scheme is given, the corresponding simulated results can be obtained so as to meet the need of optimizing urban planning. 展开更多
关键词 developing planning in an urban area meteorological environment multi-scale modeling urban planning urban environment
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Multi-scale Cyclone Activity in the Changjiang River–Huaihe River Valleys during Spring and Its Relationship with Rainfall Anomalies 被引量:10
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作者 Yujing QIN Chuhan LU Liping LI 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2017年第2期246-257,共12页
Based on the recognition framework of the outermost closed contours of cyclones, an automated identification algorithm capable of identifying the multi-scale cyclones that occur during spring in the Changjiang River-H... Based on the recognition framework of the outermost closed contours of cyclones, an automated identification algorithm capable of identifying the multi-scale cyclones that occur during spring in the Changjiang River-Huaihe River valleys (CHV) were developed. We studied the characteristics of the multi-scale cyclone activity that affects CHV and its relationship with rainfall during spring since 1979. The results indicated that the automated identification algorithm for cyclones proposed in this paper could intuitively identify multi-scale cyclones that affect CHV. The algorithm allows for effectively describing the shape and coverage area of the closed contours around the periphery of cyclones. We found that, compared to the meso- and sub-synoptic scale cyclone activities, the synoptic-scale cyclone activity showed more intimate correlation with the overall activity intensity of multi-scale CHV cyclones during spring. However, the frequency of occurrence of sub-synoptic scale cyclones was the highest, and their effect on changes in CHV cyclone activity could not be ignored. Based on the area of impact and the depth of the cyclones, the sub-synoptic scale, synoptic scale and comprehensive cyclone intensity indices were further defined, which showed a positive correlation with rainfall in CHV during spring. Additionally, the comprehensive cyclone intensity index was a good indicator of strong rainfall events. 展开更多
关键词 cyclone activity multi-scale cyclone extreme precipitation CHV area
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小区域尺度视角下的丽江市玉河健康特征研究 被引量:1
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作者 周彦辰 芮茂刚 +2 位作者 许斌 申其明 周筱妍 《三峡大学学报(自然科学版)》 CAS 北大核心 2024年第3期23-28,共6页
随着社会发展,工业化、城镇化进程不断加快,河湖生态问题日益突出且呈现更复杂的发展态势,进行河湖健康评价,开展河湖健康问题诊断,针对性地提出河湖生态系统精准治理、生态修复与保护等对策显的尤为迫切.结合丽江市典型河流玉河,以水... 随着社会发展,工业化、城镇化进程不断加快,河湖生态问题日益突出且呈现更复杂的发展态势,进行河湖健康评价,开展河湖健康问题诊断,针对性地提出河湖生态系统精准治理、生态修复与保护等对策显的尤为迫切.结合丽江市典型河流玉河,以水域岸线状况、水量水质状况、生物状况、社会服务功能等4个准则层为重要抓手,构建11个指标层的河流健康评价体系,将玉河划分为农村段、城镇段、复合段3个小区域尺度进行综合评价,探讨了小区域尺度河流健康评价差异性特征,研究表明:玉河全河段、各分段均处于亚健康状态,玉河农村段、复合段、各城镇段岸线部分指标层、准则层间健康状况差异性显著,主要存在水资源禀赋差,生态流量小,底栖动物少,局部岸线状况较差的问题. 展开更多
关键词 河流健康评价 准则层 指标层 小区域尺度
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The Influence of Time Scale on the Quantitative Study of Soil and Water Conservation Effect of Grassland
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作者 Xiaoxia WU Zhujun GU 《Asian Agricultural Research》 2015年第4期69-74,共6页
Quantitative analysis of time scale effects is conducive to further understanding of vegetation water and soil conservation mechanism.Based on the observation data of the grass covered and bare soil( control) experime... Quantitative analysis of time scale effects is conducive to further understanding of vegetation water and soil conservation mechanism.Based on the observation data of the grass covered and bare soil( control) experimental plots located in Hetian Town,Changting County of Fujian Province from 2007 to 2010,the characteristics of 4 parameters( precipitation,vegetation,RE and SE) were analyzed at precipitation event,month,season,and annual scales,and then the linear regression models were established to describe the relationships between RE( SE)and its influencing factors of precipitation and vegetation. RE( SE) means the ratio of runoff depth( soil loss) of grass covered plot to that of the control plot. Results show that these 4 parameters presented different magnitude and variation on different time scales. RE and SE were relatively stable either within or among different time scales due to their ratios reducing the influence of other factors. The coupling of precipitation and vegetation led to better water conservation effect at lower RE( < 0. 3) at precipitation event scale as well as at season scale,while the water conservation effect was dominated by precipitation at slightly higher( 0. 3- 0. 4) and higher( > 0. 7) REs at precipitation event scale as well as at annual scale( R2> 0. 78). For the soil conservation effect,precipitation or / and vegetation was / were the dominated influence factor( s) at precipitation event and annual scales,and the grass LAI could basically describe the positive conservation effect( SE <1,R2> 0. 55),while the maximum 30 min intensity( I30) could describe the negative conservation effect more accurately( SE >1,R2> 0. 79). More uncertainties( R2≈0. 4) exist in the models of both RE and SE at two moderate time scales( month and season). Consequently,factors influencing water and soil conservation effect of grass present different variation and coupling characteristics on different time scales,indicating the importance of time scale at the study on water and soil conservation. 展开更多
关键词 Time scale LEAF area INDEX Water CONSERVATION effe
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AN OBSERVATIONAL ANALYSIS OF A TORRENTIAL RAINSTORM IN THE WARM SECTOR OF SOUTH CHINA COASTAL AREAS 被引量:2
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作者 ZHENG Teng-fei YU Xin +2 位作者 HUANG Jian WAN Qi-lin LIU Xian-tong 《Journal of Tropical Meteorology》 SCIE 2018年第4期481-493,共13页
On May 20 th 2007, a brief but severe downpour rainstorm occurred in the coastal areas of Maoming and Yangjiang with rainfall of 115 mm per hour. Data from NCEP/NCAR reanalysis with 1°×1° resolution, Do... On May 20 th 2007, a brief but severe downpour rainstorm occurred in the coastal areas of Maoming and Yangjiang with rainfall of 115 mm per hour. Data from NCEP/NCAR reanalysis with 1°×1° resolution, Doppler weather radar, conventional surface observations, high-altitude radiosonde and wind profiler radar were used to analyze characteristics and contributions of synoptic scale and mesoscale systems during this torrential rainstorm. The results showed that:(1) the storm was caused by a quasi-linear mesoscale convective system(MCS) and the slow-movement of this system was the primary trigger of the torrential downpour;(2) water vapor was abundant, nearly saturated and in steady state throughout the atmosphere before the storm; intrusion of the weak dry and cold air in the middle level and a striking "dry above and wet below " structure had increased the atmospheric instability;(3) low-level southwesterly airflow from a low pressure(trough) at the Beibu Gulf provided abundant water vapor at the onset of the rainstorm; a deep dry layer was formed by dry and cold air behind the high-level trough, which facilitated latent heat release;upper-level divergence and low-level convergence circulations also provided vertical uplift for warm and moist air at the lower level;(4) Topography only played a minor role as the MCS developed and strengthened over relatively flat coastal terrain. Low level density flow induced by convection triggered new convective cell generation at the leading edge of the convective system, thereby playing a key role in the change of temperature gradient at lower layers, and resulting in strengthening atmospheric instability. 展开更多
关键词 south China coastal areas RAINSTORM in the WARM SECTOR SYNOPTIC scale systems MESOscale process
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基于5-scale模型人工针叶林叶面积指数反演 被引量:2
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作者 张云 智献坡 《中南林业调查规划》 2022年第4期32-36,52,共6页
以内蒙古赤峰市旺业甸实验林场人工针叶林为研究对象,以哨兵2A(Sentinel-2A)多光谱遥感影像和外业测量的叶面积指数为数据基础,反演人工林叶面积指数。通过5-scale模型和Liberty模型耦合得到不同输入参数与冠层反射率相对应的查找表,利... 以内蒙古赤峰市旺业甸实验林场人工针叶林为研究对象,以哨兵2A(Sentinel-2A)多光谱遥感影像和外业测量的叶面积指数为数据基础,反演人工林叶面积指数。通过5-scale模型和Liberty模型耦合得到不同输入参数与冠层反射率相对应的查找表,利用编程读取查找表与遥感影像,通过对比遥感影像中红光波段和近红外波段反射率,与查找表中红光波段和近红外波段的反射率最接近的值所对应的叶面积指数值,进而实现叶面积指数反演。结果表明:基于5-scale模型反演的叶面积指数,R2=0.8222,RMSE=0.9414,其精度要高于一元线性模型的精度,利用5-scale模型反演人工针叶林叶面积指数是可行的。 展开更多
关键词 叶面积指数 Liberty模型 5-scale模型 查找表
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