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基于优化MaxEnt模型的怒江州滑坡易发性评价
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作者 李益敏 向倩英 +1 位作者 邓选伦 冯显杰 《河南理工大学学报(自然科学版)》 CAS 北大核心 2025年第1期57-67,共11页
目的 怒江州是典型的高山峡谷地区,地质灾害(滑坡)频发,严重制约着当地的发展。为解决这一问题,方法 综合考虑怒江州实际情况,从气象水文、地形地貌、地层岩性、植被生态和人类活动5个方面选取坡向,高程等14个影响因子,判断滑坡与各影... 目的 怒江州是典型的高山峡谷地区,地质灾害(滑坡)频发,严重制约着当地的发展。为解决这一问题,方法 综合考虑怒江州实际情况,从气象水文、地形地貌、地层岩性、植被生态和人类活动5个方面选取坡向,高程等14个影响因子,判断滑坡与各影响因子间相关性,构建评价指标体系,对最大熵(maximum entropy, MaxEnt)模型的特征类(feature combination,FC)和正则化乘数(regularization multiplier, RM)参数进行优化,对比优化前后小样本赤池信息量准则(akaikeinformationcriterion,AIC)、遗漏率(omissionrate,OR)和AUC(areaunder curve),并基于优化的MaxEnt模型预测滑坡灾害的发生,实现怒江州滑坡易发性评价。结果结果表明:优化后的MaxEnt模型在研究区滑坡易发性预测中适用性优秀(AUC=0.913);运用刀切法(Jackknife)计算各影响因子对易发性的影响程度,高程(S3, 23.2%)、坡度(S9, 22.4%)、居民点密度(S5, 14.2%)、距河流距离(S13, 13.7%)、距道路距离(S4, 9.6%)和岩性(S7, 8.7%)是前六位影响因子,累计贡献度达91.8%;极高、高、中、低滑坡易发性等级的空间占比分别为4.88%,8.96%,18.40%,67.76%,县域中极高和高易发区占比最大的是泸水市,整体上看,极高、高易发区主要沿河流和道路分布于峡谷中,低易发区主要分布于人类活动少、河谷不发育的区域。结论 优化后的MaxEnt模型更适合怒江州滑坡易发性预测,研究结果可为怒江州防灾减灾与土地利用规划提供参考。 展开更多
关键词 怒江州 最大熵模型 滑坡 易发性
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Modelling the spatial distribution of snake species in northwestern Tunisia using maximum entropy(Maxent) and Geographic Information System(GIS) 被引量:9
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作者 Mohsen Kalboussi Hammadi Achour 《Journal of Forestry Research》 SCIE CAS CSCD 2018年第1期233-245,共13页
We used GIS and maximum entropy to predict the potential distribution of six snake species belong to three families in Kroumiria(Northwestern Tunisia): Natricidae(Natrix maura and Natrix astreptophora), Colubrida... We used GIS and maximum entropy to predict the potential distribution of six snake species belong to three families in Kroumiria(Northwestern Tunisia): Natricidae(Natrix maura and Natrix astreptophora), Colubridae(Hemorrhois hippocrepis, Coronella girondica and Macroprotodon mauritanicus), and Lamprophiidae(Malpolon insignitus). The suitable habitat for each species was modelled using the maximum entropy algorithm, combining presence field data(collected during 16 years:2000–2015) with a set of seven environmental variables(mean annual precipitation, elevation, slope gradient,aspect, distance to watercourses, land surface temperature and normalized Differential Vegetation Index. The relative importance of these environmental variables was evaluated by jackknife tests and the predictive power of our models was assessed using the area under the receiver operating characteristic. The main explicative variables of the species distribution were distance from streams and elevation, with contributions ranging from 60 to 77 and from 10 to 25%,respectively. Our study provided the first habitat suitability models for snakes in Kroumiria and this information can be used by conservation biologists and land managers concerned with preserving snakes in Kroumiria. 展开更多
关键词 Species distribution modelling maxent Snakes Kroumiria Tunisia
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Estimation of Potential Habitat of Caragana acanthophylla in Xinjiang Based on Maximum Entropy Model
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作者 Jinglu ZHANG Yali ZHU +2 位作者 Huifang ZHANG Jian GAO Dilixiati·Baoerhan 《Asian Agricultural Research》 2024年第4期14-18,22,共6页
[Objectives]To determine the potential habitat range of Caragana acanthophylla in Xinjiang.[Methods]The known distribution points of C.acanthophylla were used as samples,and a MaxEnt model was developed based on their... [Objectives]To determine the potential habitat range of Caragana acanthophylla in Xinjiang.[Methods]The known distribution points of C.acanthophylla were used as samples,and a MaxEnt model was developed based on their climatic variables to identify key environmental factors affecting the potential habitats of C.acanthophylla through jackknife method and construction of a response relationship between representative variables and habitat suitability;the suitability of habitats for C.acanthophylla in Xinjiang was evaluated based on the output results of the model.[Results](i)The accuracy of the model verified by AUC curve was 0.971,indicating that the potential habitats of C.acanthophylla in Xinjiang predicted by MaxEnt model were highly credible.(ii)The optimum climatic characteristics for the distribution of C.acanthophylla in Xinjiang were:isothermality 18.8%-34%,minimum temperature of coldest month-30℃to-13℃,mean temperature of coldest quarter-18℃ to-4℃,annual precipitation 80-410 mm,precipitation of driest month 0-25 mm,precipitation of driest quarter 0-82 mm,and precipitation of coldest quarter 0-75 mm.(iii)The total potential distribution area of C.acanthophylla in Xinjiang was modeled to be 1.03×10^(5) km^(2),of which 8.54×10^(3)km^(2) was high suitability area,mainly in the front mountain belt of the north slope of Tianshan Mountain in Urumqi City,Changji Hui Autonomous Prefecture,Bortala Mongol Autonomous Prefecture,and Yili Kazak Autonomous Prefecture and the front mountain belt of Barluk Mountain in Tacheng Prefecture.[Conclusions]This study is of great significance for the future scientific management,regeneration,vegetation restoration and ecological protection of C.acanthophylla. 展开更多
关键词 XINJIANG CARAGANA acanthophylla maxent model POTENTIAL HABITAT
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Research on the Assessment System of Computational Mechanics Courses Based on the TOPSIS Entropy Weight Model
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作者 Huijun Ning Ruhuan Yu +1 位作者 Qianshu Wang Mingming Lin 《Journal of Contemporary Educational Research》 2024年第6期166-182,共17页
This paper takes the assessment and evaluation of computational mechanics course as the background,and constructs a diversified course evaluation system that is student-centered and integrates both quantitative and qu... This paper takes the assessment and evaluation of computational mechanics course as the background,and constructs a diversified course evaluation system that is student-centered and integrates both quantitative and qualitative evaluation methods.The system not only pays attention to students’practical operation and theoretical knowledge mastery but also puts special emphasis on the cultivation of students’innovative abilities.In order to realize a comprehensive and objective evaluation,the assessment and evaluation method of the entropy weight model combining TOPSIS(Technique for Order Preference by Similarity to Ideal Solution)multi-attribute decision analysis and entropy weight theory is adopted,and its validity and practicability are verified through example analysis.This method can not only comprehensively and objectively evaluate students’learning outcomes,but also provide a scientific decision-making basis for curriculum teaching reform.The implementation of this diversified course evaluation system can better reflect the comprehensive ability of students and promote the continuous improvement of teaching quality. 展开更多
关键词 TOPSIS entropy weight model Computational mechanics Course assessment and evaluation system Assessment model
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Prediction of rock burst classification using cloud model with entropy weight 被引量:30
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作者 周科平 林允 +2 位作者 邓红卫 李杰林 刘传举 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2016年第7期1995-2002,共8页
The method of cloud model with entropy weight was adopted for the prediction of rock burst classification. Some main factors of rock burst including the uniaxial compressive strength (σc), the tensile strength (σ... The method of cloud model with entropy weight was adopted for the prediction of rock burst classification. Some main factors of rock burst including the uniaxial compressive strength (σc), the tensile strength (σt), the tangential stress (σθ), the rock brittleness coefficient (σc/σt), the stress coefficient (σθ /σc) and the elastic energy index (Wet) are chosen to establish evaluation index system. The entropy?cloud model and criterion are obtained through 209 sets of rock burst samples from underground rock projects. The sensitivity of indicators is analyzed and 209 sets of rock burst samples are discriminated by this model. The discriminant results of the entropy-cloud model are compared with those of Bayes, KNN and RF methods. The results show that the sensitivity order of those factors from high to low is σ_θ /σ_c, σ_θ, W_(ct), σ_c/σ_t, σ_t, σ_c, and the entropy-cloud model has higher accuracy than Bayes, K-Nearest Neighbor algorithm (KNN) and Random Forest (RF) methods. 展开更多
关键词 rock burst PREDICTION cloud model entropy weight sensitivity
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基于MaxEnt模型的北极村国家级自然保护区紫貂栖息地适宜性评价 被引量:9
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作者 刘艳华 刘磊 +6 位作者 陈红 刘小慧 王启蕃 刘鑫鑫 张子栋 张宇 周绍春 《生态学报》 CAS CSCD 北大核心 2024年第2期559-569,共11页
在人类支配的景观中,生境退化已经导致多个物种种群数量不断减少,分布范围不断缩减。紫貂(Martes zibellina)为国家Ⅰ级重点保护动物,种群数量稀少,开展栖息地适宜性研究工作对制定科学的栖息地保护计划至关重要。于2021年1月—2022年8... 在人类支配的景观中,生境退化已经导致多个物种种群数量不断减少,分布范围不断缩减。紫貂(Martes zibellina)为国家Ⅰ级重点保护动物,种群数量稀少,开展栖息地适宜性研究工作对制定科学的栖息地保护计划至关重要。于2021年1月—2022年8月在黑龙江省北极村国家级自然保护区采用样线调查法、足迹链跟踪、远红外相机监测综合收集到紫貂和猎物(雪兔)活动点信息。利用最大熵(MaxEnt)栖息地建模分析方法,首次在多个分辨率尺度背景下对紫貂种群的栖息地适宜性进行评价,研究结果表明:(1)利用ArcGIS 10.4重采样后在6个分辨率尺度(30m、60m、120m、240m、480m、960m)进行栖息地建模分析,基于主要栖息地变量因子对模型的贡献率及稳定性影响,并综合考虑研究区域面积,最终选定30m分辨率尺度作为紫貂栖息地最佳分析建模尺度,在30m分辨率尺度栖息地预测模型的曲线下面积(AUC)值为0.881;(2)研究发现猎物资源、植被类型和地形变量是影响紫貂栖息地适宜性的主要变量因子:雪兔出现概率较高、距草地与河流较近、海拔约400—600m、距常绿针叶林1.5km、距落叶针叶林约200m、坡向为50—250°的区域为紫貂的适宜栖息地;(3)栖息地适宜性分析表明,北极村国家级自然保护区紫貂适宜栖息地和次适宜栖息地面积共计23.66km2,约占保护区的17.2%,主要集中在保护区中部,而东部和西北部区域,栖息地破碎化较严重。基于模型结果与野外调查,提出了三条建议:(1)应严格控制人为活动,避免因人类干扰造成不适宜栖息地面积的持续扩大;(2)建立生态廊道促进保护区西部与中部紫貂种群进行个体交流,降低紫貂种群局部区域灭绝概率;(3)对东部地区破碎化的栖息地进行修复,扩大东部适宜栖息地面积,使破碎化的栖息地连接为整体。为分布于我国最北端的紫貂种群恢复创造条件,这对于构建该地区相对稳定的生物多样性保护空间格局有着重要意义。 展开更多
关键词 紫貂 最大熵模型 最优分辨率尺度 栖息地适宜性
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基于MaxEnt生态位模型预测当前气候条件下顶羽菊在中国的潜在适生区 被引量:1
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作者 张婷 胡诗遥 +5 位作者 杜伟 陆占军 杨明进 陈炜 张伟 徐晗 《植物保护》 CAS CSCD 北大核心 2024年第4期61-68,共8页
顶羽菊Rhaponticum repens(L.)Hidalgo又称匍匐矢车菊,为我国进境植物检疫性有害生物,是一种繁殖力、抗逆性强且难以防除的杂草,可对农作物及牧草等造成危害。本研究基于顶羽菊在全球范围内的地理分布数据,以及当前条件下影响物种分布... 顶羽菊Rhaponticum repens(L.)Hidalgo又称匍匐矢车菊,为我国进境植物检疫性有害生物,是一种繁殖力、抗逆性强且难以防除的杂草,可对农作物及牧草等造成危害。本研究基于顶羽菊在全球范围内的地理分布数据,以及当前条件下影响物种分布的环境因子,利用MaxEnt生态位模型预测顶羽菊在我国农田和草地区域的潜在分布。结果表明,影响顶羽菊潜在分布的主要环境变量为最干月份降水量、年平均温度、昼夜温差与年温差比值、最暖季度平均温度、最湿月份降水量、降水量季节性变异系数、最热月最高温度以及最干季度降水量。预测结果表明,顶羽菊在我国36°N-48°N,75°E-108°E范围高度适生,包括新疆西部、甘肃、宁夏、内蒙古三省交界处及周边地区;新疆东北部、宁夏南部、甘肃东南部、内蒙古中部、陕西和山西大部分地区、云南、西藏、四川、辽宁、黑龙江少许地区为中适生区。此外,顶羽菊对我国农田潜在危害面积达4.536万km^(2),占我国农田总面积的25.34%,对我国草地潜在危害面积达8.875万km^(2),占我国草地总面积的29.05%。综上所述,建议将我国内蒙古、宁夏、甘肃、新疆等地区列为顶羽菊高风险重点监测区,尽早采取防控措施,防患于未然。 展开更多
关键词 顶羽菊 maxent模型 潜在适生区 农田 草地
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基于MaxEnt模型的中国白刺属植物种群动态分析
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作者 姜生秀 胡静 +5 位作者 王方琳 胡小柯 王昱淇 邱晓娜 张珊 尉秋实 《中国野生植物资源》 CSCD 2024年第11期122-128,共7页
目的:了解气候变化情景下白刺属植物在中国的潜在分布和种群动态,为白刺属在中国的保护与恢复提供理论依据。方法:利用144个分布点和9个环境因子,通过MaxEnt模型,模拟白刺属在不同时期(末次冰盛期、末次间冰期、当代和未来)在中国的适... 目的:了解气候变化情景下白刺属植物在中国的潜在分布和种群动态,为白刺属在中国的保护与恢复提供理论依据。方法:利用144个分布点和9个环境因子,通过MaxEnt模型,模拟白刺属在不同时期(末次冰盛期、末次间冰期、当代和未来)在中国的适生区及迁移路线,并分析影响其分布的气候因素。结果:最暖季度的降水量(bio18)、年均温(bio1)、温度季节性变化标准差(bio4)和最冷季平均温(bio11)对白刺属分布有重要影响,其适宜范围分别为:50~250 mm、11~22.5℃、600~1400和-12.5~-2.5℃。当代气候情景下,白刺属适生区在中国西北各地区均有分布,在陕西和山西也有少量分布,适生区总面积为277.17×10^(4)km^(2),高适生区为68.92×10^(4)km^(2),中适生区为90.03×10^(4)km^(2),低适生区为118.22×10^(4)km^(2)。相比当代,末次冰盛期、末次间冰期和未来3个时期的高、中、低适生区面积均有所减少,另外,从末次冰盛期到末次间冰期,白刺属适生区总面积有所扩张。质心分析表明,在未来,白刺属有向低海拔处迁移的趋势。结论:在未来全球气候变暖的大背景下,白刺属植物将面临生存风险,应加强白刺属植物的保护和利用。 展开更多
关键词 白刺属 maxent模型 环境因子 潜在分布区 种群动态
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基于MAXENT的番茄潜叶蛾在贵州省的适生区分布预测
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作者 金剑雪 张晓明 +3 位作者 叶照春 王宇 邵昌余 张桂芬 《中国生物防治学报》 CSCD 北大核心 2024年第4期750-759,共10页
为研究番茄潜叶蛾在贵州省的适生区分布及未来扩张/收缩趋势,明确其在我省的潜在危害及威胁,利用MaxEnt生态位模型结合ArcGIS软件,基于331个分布点地理信息、23组生物气候变量及未来4种共享社会经济途径下2021—2100年的生物环境变量对... 为研究番茄潜叶蛾在贵州省的适生区分布及未来扩张/收缩趋势,明确其在我省的潜在危害及威胁,利用MaxEnt生态位模型结合ArcGIS软件,基于331个分布点地理信息、23组生物气候变量及未来4种共享社会经济途径下2021—2100年的生物环境变量对番茄潜叶蛾在我省的适生区分布及未来模式下发生趋势进行预测分析。结果表明,MaxEnt预测模型AUC值为0.958,说明模型对番茄潜叶蛾的适生区预测结果较为精准。通过刀切法筛选出11月的降水量(p11)、最冷月最低温(bio6)、年平均温(bio1)、海拔(elev)、年温变化范围(bio7)等5个因子是影响番茄潜叶蛾潜在分布的主要限制环境变量。经预测,在我省的适生区面积约为15.967万km^(2),占全省面积的99.99%,高适生区主要集中在贵阳市、安顺市、黔西南州和六盘水市大部分地区、毕节市东部地区、遵义市西北部与黔南州大部地区,面积约为8.94万km^(2),占全省面积的55.96%;中适生区主要集中在黔东南州、铜仁市、毕节西部、遵义市东南部、黔南州南部等,面积为6.47万km^(2),占比为40.54%,贵州省近99.99%的区域均为番茄潜叶蛾的适生区。从未来模式的发展趋势可知,番茄潜叶蛾在我国的适生区范围总体呈现先缩减后扩张的趋势。至2081—2100年,适生区面积变化范围在-32.74万km^(2)~8.54万km^(2)间浮动;在我省的适生区总面积没有变化,其中高适生区整体往我省西部移动;我省东部、南部、北部等部分区域将由高适生区转变为中适生区或低适生区。因此,我省将成为番茄潜叶蛾在我国扩张蔓延最重要的中转站,其西部地区也将成为高风险地区,应进一步提升对该虫的监测预警意识,积极开展该虫的预测预报及防控力度,采取积极措施防止该虫进一步扩张蔓延。 展开更多
关键词 番茄潜叶蛾 适生区预测 最大熵模型
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基于MaxEnt模型的华东地区香果树地理分布预测
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作者 王磊 周鹏 陈亚辉 《江苏林业科技》 2024年第4期41-47,共7页
香果树(Emmenopterys henryi)是中国特有的单种属珍稀濒危树种,也是第四纪冰川孑遗植物之一。华东地区香果树种群退化,江苏境内濒临灭绝。预测香果树在华东地区当前及未来时期的潜在适生区,揭示其地理分布格局变化的关键因子,对有效保... 香果树(Emmenopterys henryi)是中国特有的单种属珍稀濒危树种,也是第四纪冰川孑遗植物之一。华东地区香果树种群退化,江苏境内濒临灭绝。预测香果树在华东地区当前及未来时期的潜在适生区,揭示其地理分布格局变化的关键因子,对有效保护香果树野生资源具有重要意义。该研究以ENMeval软件包确定MaxEnt最优参数,利用54条华东地区现代地理分布记录和7个环境变量,基于优化后的MaxEnt模型预测华东地区香果树在现代、2040年、2060年和2080年的潜在分布区。综合Jackknife检验、置换重要值和贡献率,探讨制约其在华东地区分布的主导环境因子。结果表明,受试者工作特征曲线下面积(AUC值)为0.801,说明MaxEnt模型预测结果良好;当前香果树在华东地区的中度和高度适宜分布区较小,主要分布于各省山地丘陵地区;在未来气候变化情景下,香果树适生区分布会有不同程度变化,华东地区香果树在未来20 a内分布区将进一步扩张,自2040年后迅速缩小,2080年后在平原地区消失。温度因子(年均温、平均日温差、最湿季均温、温度季节变化方差)和降雨因子(年降水量、最干季降雨量)均限制着香果树的分布。 展开更多
关键词 香果树 maxent模型 地理分布 适生区 ENMeval数据包
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基于ISM-AHP-Entropy航空公司风险因素研究 被引量:1
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作者 罗凤娥 徐勇 +1 位作者 卫昌波 杜裕鑫 《航空计算技术》 2024年第2期26-31,共6页
针对航空公司风险因素研究,引入ISM-AHP-Entropy综合评价方法对风险因素进行评价。构建了风险因素指标体系,利用解析结构模型(ISM)将因素指标分为表层和深层致因,构建结构模型;根据问卷结果,用AHP-Entropy求出综合权重,结果表明人因和... 针对航空公司风险因素研究,引入ISM-AHP-Entropy综合评价方法对风险因素进行评价。构建了风险因素指标体系,利用解析结构模型(ISM)将因素指标分为表层和深层致因,构建结构模型;根据问卷结果,用AHP-Entropy求出综合权重,结果表明人因和管理因素对风险影响最为显著;进一步运用AHP-Entropy综合法分别计算表层和深层致因权重并分析,结果表明表层致因中机组资源管理水平、签派员应急处置能力影响最为显著,深层致因中安全规章方针的制定情况、应急管理培训与实施情况影响最为显著;从多个现实角度出发,结合CBTA理念,为航空公司降低风险、提高安全意识与水平提出多条建议,可供航空公司参考采纳。 展开更多
关键词 交通工程 航空公司风险因素 层次分析法 熵值法 解释结构模型
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Using MaxEnt Model to Guide Marsh Conservation in the Nenjiang River Basin, Northeast China 被引量:6
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作者 WANG Zhiliang ZHANG Bai +1 位作者 ZHANG Xuezhen Tian Hongxu 《Chinese Geographical Science》 SCIE CSCD 2019年第6期962-973,共12页
Incorporating private and working lands into protected area networks could mitigate the isolation state of protected areas(PAs) and improve the efficiency of conservation.But how to select patches of land for conserva... Incorporating private and working lands into protected area networks could mitigate the isolation state of protected areas(PAs) and improve the efficiency of conservation.But how to select patches of land for conservation is still a troublesome issue.In this study, the MaxEnt model and irreplaceability index were applied to guide marsh conservation in the Nenjiang River Basin, Northeast China.According to the high accuracy of the MaxEnt model predictions(i.e., the average AUC value = 0.933), the Wuyuer River and Zhalong marshes in the downstream reaches of Wuyuer River are the optimal habitat for the Red-crowned crane and migratory waterfowls.There are 22 marsh patches selected by the patch irreplaceability index for conservation, of which 12 patches had been included in the current network of protected areas.The other 10 patches of marsh(amounting to 1096 km^2) far from human disturbances with high NDVI(up to 0.8) and close distance to water(less than 100 m), which are excluded from the existing network of PAs, should be implemented conservation easement programs to improve the protection efficiency of conservation.Specifically, the marshes at Taha, Tangchi, and Lamadian should be given priority for conservation and restoration to reintroduce migratory waterfowls, as this would lessen the current isolation state of the Zhalong National Nature Reserve. 展开更多
关键词 maxent model IRREPLACEABILITY index MARSH CONSERVATION Red-crowned crane(Grus japonensis) Nenjiang River Basin
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Spatial-temporal Evolution and Determinants of the Belt and Road Initiative: A Maximum Entropy Gravity Model Approach 被引量:8
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作者 HUANG Qinshi ZHU Xigang +3 位作者 LIU Chunhui WU Wei LIU Fengbao ZHANG Xinyi 《Chinese Geographical Science》 SCIE CSCD 2020年第5期839-854,共16页
The spatial interaction model is an effective way to explore the geographical disparities inherent in the Belt and Road Initiative(BRI) by simulating spatial flows. The traditional gravity model implies the hypothesis... The spatial interaction model is an effective way to explore the geographical disparities inherent in the Belt and Road Initiative(BRI) by simulating spatial flows. The traditional gravity model implies the hypothesis of equilibrium points without any reference to when or how to achieve it. In this paper, a dynamic gravity model was established based on the Maximum Entropy(MaxEnt) theory to estimate and monitor the interconnection intensity and dynamic characters of bilateral relations. In order to detect the determinants of interconnection intensity, a Geodetector method was applied to identify and evaluate the determinants of spatial networks in five dimensions. The empirical study clearly demonstrates a heterogeneous and non-circular spatial structure. The main driving forces of spatial-temporal evolution are foreign direct investment, tourism and railway infrastructure construction, while determinants in different sub-regions show obvious spatial differentiation. Southeast Asian countries are typically multi-island area where aviation infrastructure plays a more important role. North and Central Asian countries regard oil as a pillar industry where power and port facilities have a greater impact on the interconnection. While Western Asian countries are mostly influenced by the railway infrastructure, Eastern European countries already have relatively robust infrastructure where tariff policies provide a greater impetus. 展开更多
关键词 spatial interaction model the Belt and Road Initiative(BRI) Maximum entropy(maxent)gravity model spatial pattern China
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Entropy squeezing and atomic inversion in the K-photon Jaynes–Cummings model in the presence of the Stark shift and a Kerr medium:A full nonlinear approach 被引量:5
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作者 H R Baghshahi M K Tavassoly A Behjat 《Chinese Physics B》 SCIE EI CAS CSCD 2014年第7期417-428,共12页
The interaction between a two-level atom and a single-mode field in the k-photon Jaynes-Cummings model (JCM) in the presence of the Stark shift and a Kerr medium is studied. All terms in the Hamiltonian, such as the... The interaction between a two-level atom and a single-mode field in the k-photon Jaynes-Cummings model (JCM) in the presence of the Stark shift and a Kerr medium is studied. All terms in the Hamiltonian, such as the single-mode field, its interaction with the atom, the contribution of the Stark shift and the Kerr medium effects are considered to be f-deformed. In particular, the effect of the initial state of the radiation field on the dynamical evolution of some physical properties such as atomic inversion and entropy squeezing are investigated by considering different initial field states (coherent, squeezed and thermal states). 展开更多
关键词 Jaynes-Cummings model entropy squeezing atomic inversion intensity-dependent coupling
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Entropy squeezing of an atom with a k-photon in the Jaynes-Cummings model 被引量:3
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作者 康冬鹏 廖庆洪 +2 位作者 Ahamd Muhammad Ashfaq 王月媛 刘树田 《Chinese Physics B》 SCIE EI CAS CSCD 2010年第1期318-325,共8页
The entropy squeezing of an atom with a k-photon in the Jaynes Cummings model is investigated. For comparison, we also study the corresponding variance squeezing and atomic inversion. Analytical results show that entr... The entropy squeezing of an atom with a k-photon in the Jaynes Cummings model is investigated. For comparison, we also study the corresponding variance squeezing and atomic inversion. Analytical results show that entropy squeezing is preferable to variance squeezing for zero atomic inversion. Moreover, for initial conditions of the system the relation between squeezing and photon transition number is also discussed. This provides a theoretical approach to finding out the optimal entropy squeezing. 展开更多
关键词 Jaynes-Cumming model entropy squeezing variance squeezing atomic inversion
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Entropy weight coefficient model and its application in evaluation of groundwater vulnerability of the Sanjiang Plain 被引量:4
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作者 LIU Rentao FU Qiang GAI Zhaomei 《Journal of Northeast Agricultural University(English Edition)》 CAS 2007年第4期368-373,共6页
The research of groundwater vulnerability is the basic work to protect the groundwater. For utilizing groundwater resource continuably, groundwater vulnerability evaluation is necessary. Useful reference to protect, e... The research of groundwater vulnerability is the basic work to protect the groundwater. For utilizing groundwater resource continuably, groundwater vulnerability evaluation is necessary. Useful reference to protect, exploit and utilize on groundwater resource are provided rationally. According to the real condition of Sanjiang Plain, the indexes system is established based on the traditional DRASTIC model. The new system includes the following seven indexes: Depth of Water, Net Recharge, Aquifer Media, Soil Media, Conductivity of the Aquifer, Land Utilizing Ratio and Populace Density. The related analysis appears that the system is rather reasonable. Because traditional methods, such as analytic hierarchy process and fuzzy mathematics theory, can't be avoided human interference in selection of weights, they could lead to an imprecise result. In order to evaluate the groundwater vulnerability reasonably, entropy weight coefficient method is applied for the first time, which provides a new way to groundwater vulnerability evaluation. The method is a model whose weights are insured by the calculation process, so the artificial disturb can be avoided. It has been used to evaluate the groundwater vulnerability in Sanjiang Plain. The satisfied result is acquired. Comparably, the same result is acquired by the other method named projection pursuit evaluation based on real-coded accelerating genetic algorithm. It shows that entropy weight coefficient method is applicable on groundwater vulnerability evaluation. The evaluation result can provide reference on the decision-making departments. 展开更多
关键词 groundwater vulnerability entropy weight coefficient model indexes system EVALUATION
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An attribute recognition model based on entropy weight for evaluating the quality of groundwater sources 被引量:21
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作者 CHEN Suo-zhong WANG Xiao-jing ZHAO Xiu-jun 《Journal of China University of Mining and Technology》 EI 2008年第1期72-75,共4页
In our study, entropy weight coefficients, based on Shannon entropy, were determined for an attribute recognition model to model the quality of groundwater sources. The model follows the theory previously proposed by ... In our study, entropy weight coefficients, based on Shannon entropy, were determined for an attribute recognition model to model the quality of groundwater sources. The model follows the theory previously proposed by Chen Q S. In the model, firstly, the author establishes the attribute space matrix and determines the weight based on Shannon entropy theory; secondly, calculates attribute measure; thirdly, evaluates that with confidence criterion and score criterion; finally, an application example is given. The results show that the water quality of the groundwater sources for the city comes up to the grade II or III standard. There is no pollution that obviously exceeds the standard and the water can meet people’s needs .The results from an evaluation of this model are in basic agreement with the observed situation and with a set pair analysis (SPA) model. 展开更多
关键词 water quality evaluation groundwater sources entropy weigh attribute recognition model
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Single-atom entropy squeezing and quantum entanglement in Tavis-Cummings model with atomic motion 被引量:2
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作者 邹艳 《Chinese Physics B》 SCIE EI CAS CSCD 2010年第7期276-283,共8页
We examine the single-atom entropy squeezing and the atom-field entanglement in a system of two moving twolevel atoms interacting with a single-mode coherent field in a lossless resonant cavity. Our numerical calculat... We examine the single-atom entropy squeezing and the atom-field entanglement in a system of two moving twolevel atoms interacting with a single-mode coherent field in a lossless resonant cavity. Our numerical calculations indicate that the squeezing period, the squeezing time and the maximM squeezing can be controlled by appropriately choosing the atomic motion and the field-mode structure. The atomic motion leads to a periodical time evolution of entanglement between the two-atom and the field. Moreover, there exists corresponding relation between the time evolution properties of the atomic entropy squeezing and that of the entanglement between the two atoms and the field. 展开更多
关键词 atomic entropy squeezing quantum reduced entropy Tavis-Cummings model atomicmotion and field-mode structure
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Predicting the potential geographic distribution of Bactrocera bryoniae and Bactrocera neohumeralis(Diptera: Tephritidae) in China using MaxEnt ecological niche modeling 被引量:7
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作者 Jing Wan QI Guo-jun +3 位作者 MA Jun Yonglin REN WANG Rui Simon MCKIRDY 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2020年第8期2072-2082,共11页
Bactrocera bryoniae and Bactrocera neohumeralis are highly destructive and major biosecurity/quarantine pests of fruit and vegetable in the tropical and subtropical regions in the South Pacific and Australia.Although ... Bactrocera bryoniae and Bactrocera neohumeralis are highly destructive and major biosecurity/quarantine pests of fruit and vegetable in the tropical and subtropical regions in the South Pacific and Australia.Although these pests have not established in China,precautions must be taken due to their highly destructive nature.Thus,we predicted the potential geographic distribution of B.bryoniae and B.neohumeralis across the world and in particular China by ecological niche modeling of the Maximum Entropy(Max Ent)model with the occurrence records of these two species.Bactrocera bryoniae and B.neohumeralis exhibit similar potential geographic distribution ranges across the world and in China,and each species was predicted to be able to distribute to over 20%of the globe.Globally,the potential geographic distribution ranges for these two fruit fly species included southern Asia,the central and the southeast coast of Africa,southern North America,northern and central South America,and Australia.While within China,most of the southern Yangtze River area was found suitable for these species.Notably,southern China was considered to have the highest risk of B.bryoniae and B.neohumeralis invasions.Our study identifies the regions at high risk for potential establishment of B.bryoniae and B.neohumeralis in the world and in particular China,and informs the development of inspection and biosecurity/quarantine measures to prevent and control their invasions. 展开更多
关键词 fruit fly Bactrocera bryoniae Bactrocera neohumeralis ecological niche modeling maxent potential geographic distribution habitat suitability
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Predicting Potential Distribution of Tibetan Spruce (Picea smithiana) in Qomolangma (Mount Everest) National Nature Preserve Using Maximum Entropy Niche-based Model 被引量:15
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作者 ZHANG Jiping ZHANG Yili +1 位作者 LIU Linshan NIE Yong 《Chinese Geographical Science》 SCIE CSCD 2011年第4期417-426,共10页
Tibetan spruce (Picea smithiana) is an endemic species of the Himalayas,and it distributes only in a re-stricted area with very low number.To address the lack of detailed distributional information,we used maximum en-... Tibetan spruce (Picea smithiana) is an endemic species of the Himalayas,and it distributes only in a re-stricted area with very low number.To address the lack of detailed distributional information,we used maximum en-tropy (Maxent) niche-based model to predict the species' potential distribution from limited occurrence-only records.The location data of P.smithiana,relative bioclimatic variables,vegetation data,digital elevation model (DEM),and the derived data were analyzed in Maxent.The receiver operating characteristic (ROC) curve was applied to assess the prediction accuracy.The Maxent jackknife test was performed to quantify the training gains from data layers and the response of P.smithiana distribution to four typical environmental variables was analyzed.Results show that the model performs well at the regional scale.There is a potential for continued expansion of P.smithiana population numbers and distribution in China.P.smithiana potentially distributes in the lower reaches of Gyirong Zangbo and Poiqu rivers in Gyirong and Nyalam counties in Qomolangma (Mount Everest) National Nature Preserve (QNNP),China.The species prefers warm temperate climate in mountain area and mainly distributes in needle-leaved evergreen closed to open forest and mixed forest along the river valley at relatively low altitudes of about 2000-3000 m.Model simulations suggest that distribution patterns of rare species with few species numbers can be well predicted by Max-ent. 展开更多
关键词 Picea smithiana maximum entropy niche-based model potential distribution Qomolangma (Mount Ev-erest) National Nature Preserve (QNNP)
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