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Structural Architecture for Development of Marginal Extensional Sub-Basins in the Red Sea Active Rift Zone
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作者 Reda Amer Mohamed Sultan +1 位作者 Robert Ripperdan John Encarnación 《International Journal of Geosciences》 2012年第1期133-152,共20页
This paper presents a robust kinematic model that describes northern Red Sea and Gulf of Suez rifting and the development of marginal extensional half-graben sub-basins (ESB). A combination of Landsat Enhanced Themati... This paper presents a robust kinematic model that describes northern Red Sea and Gulf of Suez rifting and the development of marginal extensional half-graben sub-basins (ESB). A combination of Landsat Enhanced Thematic Mapper Plus (ETM+) and structural data was used to provide model constraints on the development of rift segments and ESB in the active rift zones. Structural analysis shows rotation and change in strike of rift-bounding faults. The model describes the northern Red Sea region as a poly-phase rift system initiated by late Oligocene (30 - 24 Ma) orthogonal rifting and the development of marginal ESB (now inland ESB), followed by oblique rifting and flank uplift during the early Miocene (24 - 18 Ma). The oblique rifting fragmented the rift depression into segments separated by oblique-slip accommodation within reactivated Pan-African (ca. 600 Ma) fracture zones, resulting in the development of antithetic faults and an en-echelon distribution of inland ESB. The current phase of rifting was instigated by the development of the Dead Sea Transform in response to increased northeasterly extension during the middle Miocene (ca. 18 Ma). The model explains the widening of the Red Sea rift during the last phase more than the Gulf of Suez rift by developing more antithetic faults and formation of offshore ESB, and deepening the rift depression. 展开更多
关键词 Remote Sensing TECTONIC Model marginal sub-basins RIFT ZONE Red SEA
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Marginal Selenium Deficiency Alternates Inflammatory Response through NF-κB Pathway in LPS-induced Mouse Mastitis Model
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作者 Zhang Yixin Sun Qiaochu +3 位作者 Luo Tianning Zhang Huayu Wang Fucheng Zhang Wen 《Journal of Northeast Agricultural University(English Edition)》 2025年第2期37-46,共10页
The trace element selenium(Se)occurs naturally throughout the earth.Se deficiency has been linked to impaired breast health and other diseases in human and animals.Compared to severe Se deficiency,marginal dietary Se ... The trace element selenium(Se)occurs naturally throughout the earth.Se deficiency has been linked to impaired breast health and other diseases in human and animals.Compared to severe Se deficiency,marginal dietary Se deficiency accusers more frequently in low-Se regions.Therefore,to investigate the Se status and inflammatory response of the mammary gland under marginal dietary Se levels,an lipopolysaccharide(LPS)induced mouse mastitis model was established.Mice were fed with moderate Se diet(0.087 mg•kg^(-1) Se),adequate Se diet(0.15 mg•kg^(-1) Se)or excessive Se diet(1.5 mg•kg^(-1) Se)for 60 days.Se status and inflammatory factors were investigated.Results showed that the Se status of mammary gland correlated with dietary Se levels.Marginal Se deficiency exacerbated mammary tissue histopathology;increased the mRNA level of inflammatory genes tumor necrosis factor alpha(TNF-α),interleukin-1β(IL-1β)and cyclooxygenase-2(COX-2);and enhanced the phosphorylation of NF-κB p65 in mammary gland tissues.Supplementation of Se in diet higher than recommended levels reduced the inflammatory reaction of mammary glands in LPS-induced mastitis model and provided a protective effect. 展开更多
关键词 marginal selenium deficiency MASTITIS INFLAMMATION NF-κB signal pathway
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Rift marginal coarse-grained sediment gravity flow deposits in the Eocene Dongying Depression,Bohai Bay Basin,China:Balancing tectonic and climatic controls
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作者 Rong-Heng Tian Ben-Zhong Xian +8 位作者 Peng Chen Lin Zhao Naveed Ur Rahman Muhammad Ubaid Umar Qian-Ran Wu Qian Li Wen-Miao Zhang Jian-Ping Liu Si-Rui Chen 《Petroleum Science》 2025年第8期3168-3188,共21页
Previous studies have indicated that sediment gravity flow deposits developed in lacustrine active extensional rift basins are primarily influenced by tectonics and to a lesser extent by climate.Our present work revea... Previous studies have indicated that sediment gravity flow deposits developed in lacustrine active extensional rift basins are primarily influenced by tectonics and to a lesser extent by climate.Our present work reveals that climate can obscure the effect of tectonic subsidence by regulating sediment supply;conversely,tectonics can impede the sedimentary manifestation of climatic impacts.Here a case study has been presented to assess the impact of climate-modulated rapid lake-level rise and tectonic subsidence on the development of coarse-grained gravity flow deposits in the Dongying rift margin of the Bohai Bay Basin,eastern China.The lithofacies analysis reveals frequent bed amalgamation,abundant thick massive coarse-grained deposits,widespread cross bedding and plant fragments,and incomplete composite bed formed by high-energy erosion,indicating that the hyperpycnal flow is an important mechanism driving the deposition of these coarse-grained sediments.Detailed sequence stratigraphic analysis and sediment dispersal pattern suggest that the long-striped nearshore subaqueous fan systems induced by outburst-flood hyperpycnal flow distributed along the border fault,are primarily controlled by long-term tectonics,while the rapid rise of lake level driven by short-term climate change possibly intensifies seasonal flood-generated hyperpycnal flow occurrences and consequently promotes the basinal fan progradation.The maximum scale of these coarse-grained gravity flow deposits of the basinal fan systems are typically attained during the transgressive systems tract,which deviates from the classical sequence stratigraphic model.Furthermore,it presented a continuous transition from the proximal to the distal part,encompassing traction flows and turbidity currents during the periods of relatively stable tectonics.Nevertheless,gravel-rich debris flows appear to predominate the dispersion of coarse-grained sediments during periods characterized by intense tectonic activity.The coarse-grained gravity flow deposits in the lacustrine rift margin reported here,challenge the traditional beliefs:this study suggests that subaqueous deposits abundantly preserved in the transgressive setting. 展开更多
关键词 Tectonic activity Climatic fluctuation Rift margin Gravity flow deposits
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Deep-water Natural Gas Differential Migration and Enrichment in East African Transform Continental Marginal Basins
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作者 CAI Jun HE Youbin +1 位作者 LIANG Jianshe GUO Rong 《Acta Geologica Sinica(English Edition)》 2025年第4期1105-1118,共14页
Compared to discrete continental marginal basins,the mechanisms of hydrocarbon migration and enrichment in transform continental marginal basins are poorly understood.In this study,we conducted a comprehensive analysi... Compared to discrete continental marginal basins,the mechanisms of hydrocarbon migration and enrichment in transform continental marginal basins are poorly understood.In this study,we conducted a comprehensive analysis of the main source rocks,reservoirs,and vertical migration pathways within the Rovuma(RB)and Tanzania(TB)basins in East Africa utilizing drilling,logging,seismic,and geochemical data.The results indicate that the enhanced preservation conditions of the Lower Jurassic source rocks in the southwest could lead to the discovery of large natural gas fields in the southern TB and RB.The primary reservoir is a deep-water turbidite sandstone.Due to topographic differences,the expanse of the turbidite sandstones in the RB is significantly larger than those in Tanzania.The main vertical migration pathways are the western boundary fault zone of the Kerimbas Graben(WBFZ)and the Seagap fault zone(SFZ).In the RB,natural gas migrates vertically along the WBFZ and preferentially accumulates in the deep-water turbidite sandstones of the footwall under the control of the fluid potential.Conversely,in the southern TB,the deep natural gas first migrates upward along the SFZ,then moves along the shallow branch faults in the sandstones on both sides of the SFZ. 展开更多
关键词 upstream exploration natural gas differential enrichment transform continental marginal basin fault activity DEEP-WATER Mozambique-Tanzania
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Genesis of pink diamonds in lamproite and low-Ti-type kimberlite pipes on craton margins
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作者 GROVES DI ZHANG Liang +1 位作者 CHEN ZuYan BAI Feng 《岩石学报》 北大核心 2026年第2期383-392,共10页
Diamonds were formed in the mantle lithosphere,mostly at depths of 150~200km in the centres of Precambrian cratons,the buoyant ancient cores of continents.From there they were normally transported into the upper crust... Diamonds were formed in the mantle lithosphere,mostly at depths of 150~200km in the centres of Precambrian cratons,the buoyant ancient cores of continents.From there they were normally transported into the upper crust in kimberlite pipes whose diamonds are largely colourless and light yellow related to trace element N(Ia type),although brown,green,and more rarely blue-coloured diamonds are related to lattice defect and trace amounts of H,more rarely B and Ni.Pink diamonds are extremely rare in the approximately 90 diamondiferous pipes mined globally.Although small quantities have been discovered elsewhere,about 90%have been mined from the ca.1.3Ga Argyle diamond pipe in Western Australia,with the Arkhangelskaya diamond pipe in Russia the only other significant source.The pink colour at both Argyle and Arkhangelskaya is unrelated to trace elements and instead results from absorption of light from nanoscale(550nm)defects related to shear stress and plastic deformation.Macroscopically,defects are shown by glide planes,lamellae,and grain lines imposed on the originally colourless diamonds derived from their mantle source.The key question is why these defects were uniquely acquired in diamonds in the Argyle and Arkhangelskaya pipes.Unlike most diamondiferous pipes,Argyle is a rare diamondiferous volatile-rich lamproite pipe that was emplaced into the multiply deformed and rifted NNE-trending Halls Creek Orogen on the margin of the Kimberley Craton.Similarly,Arkhangelskaya in the Devonian Lomonosov kimberlite cluster is a volatile-rich low-Ti type kimberlite,a close relative to lamproite,that was emplaced into the multiply deformed Lapland-Kola Orogen on the rifted margin of the Kola Craton.These craton margins are underlain by subduction-induced volatile-enriched metasomatized mantle lithosphere in contrast to the more primeval mantle under craton centres.It is thus likely that shear stresses were exacerbated at Argyle and Arkangelskaya by rapid vertical emplacement of the anomalous volatile-enriched magmas at supercritical pressures and temperatures,that induced catastrophic phase separation of these volatiles and'mini seismic events'during rapid pressure drops during ascent from 200km depth to the surface.Such a mechanism is consistent with the presence of strongly resorbed and plastically deformed small brown industrial diamonds in the Argyle pipe.From a China perspective,it is potentially important that at 1.3Ga the alkaline Argyle pipe in northern Australia is placed adjacent to the North China Craton(NCC),with numerous world-class mineral deposits including the giant ca.1.4~1.2Ga alkaline Bayan Obo REE system on its margin.However,it is the southeastern margin of the Yangtze Craton and the Jiangnan Orogen with their lamproite pipes derived from metasomatized mantle lithosphere that present the most prospective regions for pink diamond occurrences. 展开更多
关键词 Pink diamond Plastic deformation LAMPROITE Low-Ti-type kimberlite Craton margin
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Fusion of deep learning and machine learning methods for hourly locational marginal price forecast in power systems
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作者 Matin Farhoumandi Sheida Bahramirad +5 位作者 Ahmed Alabdulwahab Mohammad Shahidehpour Farrokh Rahimi Ali Ipakchi Farrokh Albuyeh Sasan Mokhtari 《iEnergy》 2025年第3期193-204,共12页
In this paper,we propose STPLF,which stands for the short-term forecasting of locational marginal price components,including the forecasting of non-conforming hourly net loads.The volatility of transmission-level hour... In this paper,we propose STPLF,which stands for the short-term forecasting of locational marginal price components,including the forecasting of non-conforming hourly net loads.The volatility of transmission-level hourly locational marginal prices(LMPs)is caused by several factors,including weather data,hourly gas prices,historical hourly loads,and market prices.In addition,variations of non-conforming net loads,which are affected by behind-the-meter distributed energy resources(DERs)and retail customer loads,could have a major impact on the volatility of hourly LMPs,as bulk grid operators have limited visibility of such retail-level resources.We propose a fusion forecasting model for the STPLF,which uses machine learning and deep learning methods to forecast non-conforming loads and respective hourly prices.Additionally,data preprocessing and feature extraction are used to increase the accuracy of the STPLF.The proposed STPLF model also includes a post-processing stage for calculating the probability of hourly LMP spikes.We use a practical set of data to analyze the STPLF results and validate the proposed probabilistic method for calculating the LMP spikes. 展开更多
关键词 Locational marginal price forecasting machine learning deep learning non-conforming net loads probability of price spikes
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RDV Protonic Activation for EOR in Active,Mature Reservoirs and Marginal Wells
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作者 William J.Jimenez Carlos A.Rivera +1 位作者 Hector J.Sulvaran Hernan O.Gonzalez 《Journal of Energy and Power Engineering》 2025年第4期133-140,共8页
This study documents pioneering results in marginal wells in Texas,where the application of RDV-00■restored production through delayed protonic activation catalyzed by reservoir energy.The product,based on RDV■(Vaso... This study documents pioneering results in marginal wells in Texas,where the application of RDV-00■restored production through delayed protonic activation catalyzed by reservoir energy.The product,based on RDV■(Vasoactive Dynamic Reactor)technology,operates via:Controlled protonation of molecular structures;Release of energetic carbocations;Autonomous transformation without external inputs.(a)Case 1(Well#E2-Starr County):Certified as“dry”by RRC(2022)after 48 months at 0 BPD;8 months post-injection of 5 gal RDV-00■(Fluid column:37 bbl;Wellhead pressure:80 psi(vs.0 psi initially)).(b)Case 2(Well#P1-Luling Field):Historical stripper well(0.25-0.5 BPD);23 months of immobilization with 15 gal RDV-00■;Critical results:(1)Initial production:42 BPD(8,400%above baseline);(2)Shut-in wellhead pressure:40 psi(neighboring wells=0-3 psi);(3)Current behavior:Continuous recharge from reservoir(well shut-in due to lack of storage).(c)Technically Significant Observations:(1)First case of self-sustaining reactivation in depleted wells;(2)Mechanism validated by Autonomous pressure generation(0→40-80 psi),and Continuous flow without additional stimulation;(3)No documented precedents in SPE/OnePetro literature to our knowledge. 展开更多
关键词 Enhanced recovery marginal wells protonic activation CARBOCATIONS RDV-00■ autogenous pressure viscoactive rheology delayed activation autonomous EOR(enhanced oil recovery)
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Evaluating climate-induced productivity of typical ecosystems of the eastern margin of the Qinghai-Tibet Plateau
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作者 ZHENG Huazhu YAO Zhengyu +6 位作者 LU Jungang WU Yongjiao YE Quan ZHAO Hongfei OUYANG Maolin Claudio ODELANG HE Hongming 《Journal of Geographical Sciences》 2026年第1期107-128,共22页
Ecosystems along the eastern margin of the Qinghai-Tibet Plateau(EQTP)are highly fragile and extremely sensitive to climate change and human disturbances.To quantitatively assess climate-induced ecosystem responses,th... Ecosystems along the eastern margin of the Qinghai-Tibet Plateau(EQTP)are highly fragile and extremely sensitive to climate change and human disturbances.To quantitatively assess climate-induced ecosystem responses,this study proposes a Climate-Induced Productivity Index(CIPI)based on the Super Slack-Based Measure(Super-SBM)model using remote sensing data from 2001 to 2020.The results reveal persistently low CIPI values(0.47-0.53)across major ecosystem types,indicating widespread vulnerability to climatic variability.Among these ecosystems,forests exhibit the highest CIPI(0.55),followed by shrublands(0.54),croplands(0.53),grasslands(0.51),and barelands(0.43).The Theil index analysis further demonstrates significant intra-group disparities,suggesting that extreme climatic events amplify CIPI heterogeneity.Moreover,the dominant environmental drivers differ among ecosystem types:the Palmer Drought Severity Index(PDSI)primarily constrains grassland productivity,solar radiation(SRAD)strongly influences shrub and cropland systems,whereas subsurface factors exert greater control in forested regions.This study provides a quantitative framework for evaluating climate-ecosystem interactions and offers a scientific basis for long-term ecological monitoring and security planning across the EQTP. 展开更多
关键词 climate-induced productivity index(CIPI) Super-SBM model ecosystem vulnerability environmental drivers eastern margin of Qinghai-Tibet Plateau
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快速Marginalized粒子滤波器在纯方位跟踪中的应用 被引量:1
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作者 薛锋 刘忠 石章松 《火力与指挥控制》 CSCD 北大核心 2008年第11期66-68,72,共4页
为提高纯方位跟踪性能,降低粒子滤波方法的运算量,在原有Marginalized粒子滤波器(MPF)的基础上,对线性部分处理方法进行简化,提出了快速Marginalized粒子滤波器(FMPF),并结合纯方位跟踪模型,推导了FMPF应用的具体算法步骤,使用机动目标... 为提高纯方位跟踪性能,降低粒子滤波方法的运算量,在原有Marginalized粒子滤波器(MPF)的基础上,对线性部分处理方法进行简化,提出了快速Marginalized粒子滤波器(FMPF),并结合纯方位跟踪模型,推导了FMPF应用的具体算法步骤,使用机动目标纯方位跟踪仿真实例,与其他滤波器进行了仿真对比,分析了跟踪性能和计算量。仿真结果表明,与标准粒子滤波器相比,FMPF可以提高线性部分的计算精度,同时减少MPF所需的计算量。 展开更多
关键词 纯方位跟踪 粒子滤波 marginalized粒子滤波器 运算时间
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Temporal-Spatial Variances of Holocene Precipitation at the Marginal Area of the East Asian Monsoon Influences from Pollen Evidence 被引量:6
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作者 刘鸿雁 崔海亭 +1 位作者 田育红 徐丽宏 《Acta Botanica Sinica》 CSCD 2002年第7期864-871,共8页
The woodland-steppe ecotone in the. southern Nei Mongol Plateau is located at the northern edge of the east Asian monsoon influences. A marked southeastern - northwestern (SE - NW) precipitation gradient exists in thi... The woodland-steppe ecotone in the. southern Nei Mongol Plateau is located at the northern edge of the east Asian monsoon influences. A marked southeastern - northwestern (SE - NW) precipitation gradient exists in this region. Quantitative reconstruction of palaeo-precipitation of this region is helpful to reveal the development of monsoon climate and to predict die future desertification. Based on modern vegetation and surface pollen studies, a pollen-precipitation transfer function in the study region was established. Pollen data from three sediment sequences within the ecotone were used to reconstruct palaeo-precipitation during the Holocene. The processes of precipitation changes in the three sequences were quite different. There was a tendency of precipitation declined from the onset of the Holocene to 1 100 a BP in Haoluku. But, in Liuzhouwan and Xiaoniuchang, both located south of Haoluku, the annual precipitation reached highest values during 7 800 - 6 200 a BP and 7 200 - 5 000 a BP, respectively. The influences of southwestern (SW) monsoon and the variances of topographical conditions have possibly caused these temporal-spatial variances. 展开更多
关键词 marginal area of the monsoon climate WOODLAND steppe ecotone Nei Mongol Plateau pollen-climate transfer function
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基于权重一致性优化的实时Marginalized粒子滤波算法 被引量:2
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作者 胡振涛 刘先省 +1 位作者 金勇 侯彦东 《电子学报》 EI CAS CSCD 北大核心 2014年第10期1970-1976,共7页
针对Marginalized粒子滤波中随机量测噪声对于非线性状态估计精度的不利影响以及线性状态估计中计算量较大问题,提出了一种基于权重一致性优化的实时Marginalized粒子滤波算法.首先,结合量测系统建模中先验信息的提取和利用,通过粒子权... 针对Marginalized粒子滤波中随机量测噪声对于非线性状态估计精度的不利影响以及线性状态估计中计算量较大问题,提出了一种基于权重一致性优化的实时Marginalized粒子滤波算法.首先,结合量测系统建模中先验信息的提取和利用,通过粒子权重间一致性距离和一致性矩阵的构建,提出了量测提升策略下权重的一致性优化方法,以改善粒子滤波在非线性状态估计中的滤波精度.其次,通过对Marginalized粒子滤波实现中时间更新和量测更新环节的结构优化,给出了实时Marginalized粒子滤波,以降低蒙特卡罗仿真实现下卡尔曼滤波在状态线性估计中的计算复杂度.最后,在两者的动态结合基础上给出了新算法具体实现步骤.利用基于单站雷达目标跟踪仿真场景,分析了算法性能.理论分析和仿真实验结果验证了算法的可行性和有效性. 展开更多
关键词 非线性估计 marginalized粒子滤波 量测提升 权重优化
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Analyzing our educational resource deployment of compulsory education by marginal utility
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作者 高丽 程宝良 《陕西师范大学学报(哲学社会科学版)》 CSSCI 北大核心 2006年第S1期353-356,共4页
In the base of utility and marginal utility,the article put forwardthe concept of utility and marginal utilityof educational outlay and the theory of them,and analyzed the actuality of educational resource deployment ... In the base of utility and marginal utility,the article put forwardthe concept of utility and marginal utilityof educational outlay and the theory of them,and analyzed the actuality of educational resource deployment in ourcountry,gave some advice about howtoi mprove our educational resource deployment of compulsory education. 展开更多
关键词 marginal utility educational resource compulsory education
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Effects of Sowing Rate on Marginal Superiority and Yield of Wheat in Wheat-cotton Intercropping System
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作者 王树林 祁虹 +4 位作者 王燕 张谦 冯国艺 林永增 梁青龙 《Agricultural Science & Technology》 CAS 2015年第12期2649-2652,共4页
In the wheat-cotton intercropping system, total 6 sowing rates (187.5, 225.0, 262.5, 300.0, 337.5 and 375.0 kg/hm2) were arranged, and the effects of sowing rate on marginal superiority and yield of wheat were inves... In the wheat-cotton intercropping system, total 6 sowing rates (187.5, 225.0, 262.5, 300.0, 337.5 and 375.0 kg/hm2) were arranged, and the effects of sowing rate on marginal superiority and yield of wheat were investigated. The re- sults showed that the effect of sowing rate on inner-line wheat was greater than that on side-line wheat; with the increased sowing rate, the marginal superiority of panicle number was reduced in overall, and the difference in panicle number be- tween inner and side lines was decreased from 9.0×10^5/hm2 (sowing rate of 187.5 kg/hm2) to 7.8×10^5/hm2 (sowing rate of 375.0 kg/hm2); the marginal superiority of grains per spike was increased first and then reduced, and the largest difference in grains per spike between the inner and side lines reached 4.6 under the sowing rate of 300.0 kg/hm2; the marginal superiority of 1 000-grain weight and yield was gradually increased, and the largest difference in 1 000-grain weight between the inner and side lines reached 3.9 g under the sowing rate of 337.5 kg/hm2, and in yield reached 3 136.5 kg/hm2under the sowing rate of 375.0 kg/hm2. The effects of sowing rate on the three yield factors of intercropped wheat ranked as panicle number 〉 grains per spike 〉 1 000-grain weight. The appropriate sowing rate of wheat was 225.0-262.0 kg/hm2 in the wheat-cotton intercropping system. 展开更多
关键词 Wheat-cotton intercropping WHEAT Sowing rate marginal superiority YIELD
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Analysis on Marginal Superiority and Yield of Different Wheat Varieties in Wheat-cotton Intercropping System
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作者 王树林 祁虹 +4 位作者 王燕 张谦 冯国艺 林永增 梁青龙 《Agricultural Science & Technology》 CAS 2016年第5期1077-1079,共3页
In wheat-cotton intercropping system,the spike number per unit area,grains per spike,thousand-grain weight and yield of side line and inner line were investigated in six wheat varieties to study the marginal superiori... In wheat-cotton intercropping system,the spike number per unit area,grains per spike,thousand-grain weight and yield of side line and inner line were investigated in six wheat varieties to study the marginal superiority and select suitable wheat varieties intercropped with cotton.The results showed that Xingmai No.4had obvious marginal superiority with the yield of 6 919.0 kg/hm2,so it was the suitable variety for wheat-cotton intercropping system. 展开更多
关键词 Wheat-cotton intercropping Wheat variety marginal superiority
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基于自适应粒子群优化的代价评估Marginalized粒子滤波 被引量:1
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作者 胡振涛 魏丹 +1 位作者 金勇 胡玉梅 《计算机科学》 CSCD 北大核心 2014年第6期199-203,共5页
针对量测受扰动情况下粒子重要性权重的精确度量和粒子的有效采样问题,提出了一种基于自适应粒子群优化的代价评估Marginalized粒子滤波。首先,在Marginalized粒子滤波框架下,通过引入代价函数和风险函数,实现了粒子重要性权重评价过程... 针对量测受扰动情况下粒子重要性权重的精确度量和粒子的有效采样问题,提出了一种基于自适应粒子群优化的代价评估Marginalized粒子滤波。首先,在Marginalized粒子滤波框架下,通过引入代价函数和风险函数,实现了粒子重要性权重评价过程中对最新量测信息的合理利用,以降低传统的依据重要性权重度量方式中对于噪声先验信息的依赖。其次,通过对粒子分布特征信息的提取和利用,构建了粒子极限速度设定的自适应选取策略,给出了一种自适应粒子群优化方法。在此基础上,结合粒子群优化中群体优化机理来提升采样粒子对被估计状态的逼近程度,进而改善重采样后粒子的多样性。理论分析和仿真实验验证了算法的有效性。 展开更多
关键词 非线性滤波 代价评估粒子滤波 粒子群优化 量测不确定
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Farmland marginalization in the mountainous areas: Characteristics, influencing factors and policy implications 被引量:26
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作者 SHAO Jing'an ZHANG Shichao LI Xiubin 《Journal of Geographical Sciences》 SCIE CSCD 2015年第6期701-722,共22页
Based on SPOT-5 images, 1:1 million topographic maps, the maps of the returning farmland to forest project and the Chongqing forest project, social and economic statistics, etc., this paper identifies the features an... Based on SPOT-5 images, 1:1 million topographic maps, the maps of the returning farmland to forest project and the Chongqing forest project, social and economic statistics, etc., this paper identifies the features and factors influencing farmland marginalization. The results showed: (1) During 2002-2012, the rate of farmland marginalization was 16.18%, which was mainly found in the high areas of northern Qiyao mountains and the medium-altitude areas of southern Qiyao mountains. And this farmland marginalization will increase, associated with non-agriculturalization of rural labourers and aging of the remaining labourers. (2) Elevation, distance radius from villages and road connections had a great in- fluence on farmland marginalization. Farmland marginalization rates showed an increasing trend with the increase of elevation, and 60.88% of the total farmland marginalization area is found at an altitude greater than 1000 m above sea level. The marginalization trend also increases with slope and distance from the distribution network. (3) Farmland area per labourer and the average age of farm labourers were major factors driving farmland marginalization. Farmland transfer and small agricultural machinery sets affect farmland marginalization with respect to management and productivity efficiency. (4) Farmland with "comparative-disadvantage-dominated marginalization" accounted for 55.32% of the total farmland marginalization area, followed by "location-dominated marginalization" (33.80%). (5) According to the specifics of each real situation, different policies are suggested to mitigate the margin- alization. A "continuous marginalization" policy will encourage the return of farmland to forest in "terrain-dominated marginalization". An "anti-marginalization" policy is suggested to create new rural accommodation and improve the rural road system to counteract "terrain-dominated marginalization". And another "anti-marginalization" policy is planned to improve management and micro-mechanization for "comparative-disadvantage-dominated marginalization". A new idea was developed to integrate high resolution remote sensing and statistical data with survey information to identify land marginalization and its driving forces in mountainous areas. 展开更多
关键词 farmland marginalization FEATURES influencing factors policy implications mountainous area
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The Marginal Rao-Blackwellized Particle Filter for Mixed Linear/Nonlinear State Space Models 被引量:17
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作者 Yin Jianjun Zhang Jianqiu Mike Klaas 《Chinese Journal of Aeronautics》 SCIE EI CAS CSCD 2007年第4期346-352,共7页
In this paper, the marginal Rao-Blackwellized particle filter (MRBPF), which fuses the Rao-Blackwellized particle filter (RBPF) algorithm and the marginal particle filter (MPF) algorithm, is presented. The state... In this paper, the marginal Rao-Blackwellized particle filter (MRBPF), which fuses the Rao-Blackwellized particle filter (RBPF) algorithm and the marginal particle filter (MPF) algorithm, is presented. The state space is divided into linear and non-linear parts, which can be estimated separately by the MPF and the optional Kalman filter. Through simulation in the terrain aided navigation (TAN) domain, it is demonstrated that, compared with the RBPF, the root mean square errors (RMSE) and the error variance of the nonlinear state estimations by the proposed MRBPF are respectively reduced by 29% and 96%, while the unique particle count is increased by 80%. It is also found that the MRBPF has better convergence properties, and analysis has shown that the existing RBPF is nothing more than a special case of the MRBPF. 展开更多
关键词 signal processing marginal Rao-Blackwellized particle filter SIMULATION mixed linear/nonlinear terrain aided navigation
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Marginal optimization method to improve the inconsistent comparison matrix in the analytic hierarchy process 被引量:11
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作者 Shihui Wu Jiang Xie +3 位作者 Xiaodong Liu Bo He Minxiang Yang Zhengxin Li 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2017年第6期1141-1151,共11页
To improve the inconsistency in the analytic hierarchy process(AHP), a new method based on marginal optimization theory is proposed. During the improving process, this paper regards the reduction of consistency ratio(... To improve the inconsistency in the analytic hierarchy process(AHP), a new method based on marginal optimization theory is proposed. During the improving process, this paper regards the reduction of consistency ratio(CR) as benefit, and the maximum modification compared to the original pairwise comparison matrix(PCM) as cost, then the improvement of consistency is transformed to a benefit/cost analysis problem. According to the maximal marginal effect principle, the elements of PCM are modified by a fixed increment(or decrement) step by step till the consistency ratio becomes acceptable, which can ensure minimum adjustment to the original PCM so that the decision makers’ judgment is preserved as much as possible. The correctness of the proposed method is proved mathematically by theorem. Firstly, the marginal benefit/cost ratio is calculated for each single element of the PCM when it has been modified by a fixed increment(or decrement).Then, modification to the element with the maximum marginal benefit/cost ratio is accepted. Next, the marginal benefit/cost ratio is calculated again upon the revised matrix, and followed by choosing the modification to the element with the maximum marginal benefit/cost ratio. The process of calculating marginal effect and choosing the best modified element is repeated for each revised matrix till acceptable consistency is reached, i.e., CR<0.1. Finally,illustrative examples show the proposed method is more effective and better in preserving the original comparison information than existing methods. 展开更多
关键词 analytic hierarchy process(AHP) comparison matrix CONSISTENCY marginal optimization
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Soil Properties and Characteristics of Soil Aggregate in Marginal Farmlands of Oasis in the Middle of Hexi Corridor Region, Northwest China 被引量:19
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作者 SUYong-zhong WANG Fang +1 位作者 ZHANG Zhi-hui DU Ming-wu 《Agricultural Sciences in China》 CAS CSCD 2007年第6期706-714,共9页
The composition and stability of soil aggregate are closely related to soil quality, soil erosion, and agricultural sustainability. In this study, 49 soil samples at the 0-10 cm surface layer were collected from four ... The composition and stability of soil aggregate are closely related to soil quality, soil erosion, and agricultural sustainability. In this study, 49 soil samples at the 0-10 cm surface layer were collected from four soil types (i.e., Ari-Sandic Primosols, Calci-Orthic Aridosols, Siltigi-Otrthic Anthrosols, and Ustic Cambosols) in the marginal farmland in the oasis of the middle Hexi Corridor region and was used to determine the characteristics of soil aggregates. The composition of dry- and wet- sieved aggregates and the physical and chemical properties (including soil particle distribution, soil organic carbon (SOC), calcium carbonate (CaCO3), and oxides of Fe^3+ and Al^3+) of the selected soils were analyzed. The results show that soil particle size distribution is dominated by fine sand fraction in most of soils except Ustic Cambosols. Soil organic carbon concentration is 5.88 ± 2.52 g kg^-1 on average, ranging from 4.75 g kg^-1 in Ari-Sandic Primosols to 10.51 g kg^-1 in Ustic Cambosols. The soils have high calcium carbonate (CaCO3) concentration, ranging from 84.7 to 164.8 g kg^-1, which is increased with soil fine particle and organic carbon content. The percentage of 〉0.25 mm dry aggregates ranges from 65.2% in Ari-Sandic Primosols to 94.6% in Ustic Cambosols, and large dry blocky aggregates (〉5 mm) is dominant in all soils. The mean weight diameter of dry aggregates (DMWD) ranges from 3.2 mm to 5.5 mm. The percentage of 〉0.25 mm water-stable aggregate is from 23.8% to 45.4%. The percentage of aggregate destruction (PAD) is from 52.4% to 66.8%, which shows a weak aggregate stability. Ari-Sandic Primosols has the highest PAD. The distribution and characteristics of soil aggregates are in favor of controlling soil wind erosion. However, the stability of aggregate of all soils is weak and soils are prone to disperse and harden after irrigation. The mass of macro-aggregates and DMWD are positively significantly correlated with the contents of soil clay and silt, soil organic carbon (SOC), CaCO3, and oxides of Fe^3+ and Al^3+. Soil fine silt and clay, SOC and CaCO3 are important agents of aggregation in this region, and the effect of SOC and CaCO3 on aggregate stability is more significant than that of soil silt and clay. Converting cropland to alfalfa forage land can increase SOC concentration, and in turn, enhance the formation of aggregates and stability. For the marginal farmlands in this fragile ecological area, converting cropland to alfalfa grassland or performing crop-grass rotation is an effective and basic strategy to improve soil structure and quality, to mitigate soil wind erosion, and to enhance oasis agricultural sustainability. 展开更多
关键词 soil aggregate soil properties returning cropland to grassland marginal oasis Hexi Corridor region
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The mechanism of farmland marginalization in Chinese mountainous areas:Evidence from cost and return changes 被引量:7
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作者 LI Shengfa LI Xiubin 《Journal of Geographical Sciences》 SCIE CSCD 2019年第4期531-548,共18页
Farmland marginalization has become the main trend of land-use change in the mountainous areas of China. Using annual survey data of major agricultural production costs and earnings at national and provincial levels i... Farmland marginalization has become the main trend of land-use change in the mountainous areas of China. Using annual survey data of major agricultural production costs and earnings at national and provincial levels in China, this study aims to analyze the reasons and mechanism behind farmland marginalization in mountainous areas. We find that farmers on plains are able to reduce their per mu labor input effectively through intensive use of agricultural machinery, which has minimized the impact of the increase in labor price. However, it is extremely challenging for farmers in mountainous areas to use the same method owing to the rough terrain. Thus, per laborer farming area in these areas has increased relatively slowly, causing a widening gap in agricultural labor productivity between the two regions. With the rapid rise in labor costs since 2003, the marginalization of cultivated land in mountainous areas is evident. In 2013, the net profit of agricultural production in mountainous China fell below zero. Since 2000, the land-use and land-cover change in these areas was characterized by the reduction of farmland area, reforestation, and the enhancement of the NDVI value. The high correlation between the NDVI change rate and the ratio of change in farmland(r = –0.70) and forest(r = 0.91) in mountainous areas at provincial level further attests to the trend of farmland marginalization there. Finally, we summarize the mechanism of such marginalization against the backdrop of the rapid increase in the opportunity cost of farming and the rapid fall of agricultural labor forces in mountainous areas. This study contributes to a deep understanding of the development process of farmland marginalization and abandonment as well as forest transition in Chinese mountainous areas. 展开更多
关键词 FARMLAND marginalIZATION FARMLAND ABANDONMENT LABOR COSTS returns agricultural LABOR productivity mountainous areas China
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