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Seasonal Variation of the Sea Surface Temperature Growth Rate of ENSO
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作者 Xinyi XING Xianghui FANG +1 位作者 Da PANG Chaopeng JI 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2024年第3期465-477,共13页
El Ni?o–Southern Oscillation(ENSO) exhibits a distinctive phase-locking characteristic, first expressed during its onset in boreal spring, developing during summer and autumn, reaching its peak towards winter, and de... El Ni?o–Southern Oscillation(ENSO) exhibits a distinctive phase-locking characteristic, first expressed during its onset in boreal spring, developing during summer and autumn, reaching its peak towards winter, and decaying over the next spring. Several studies have demonstrated that this feature arises as a result of seasonal variation in the growth rate of ENSO as expressed by the sea surface temperature(SST). The bias towards simulating the phase locking of ENSO by many state-of-the-art climate models is also attributed to the unrealistic depiction of the growth rate. In this study, the seasonal variation of SST growth rate in the Ni?o-3.4 region(5°S–5°N, 120°–170°W) is estimated in detail based on the mixed layer heat budget equation and recharge oscillator model during 1981–2020. It is suggested that the consideration of a variable mixed layer depth is essential to its diagnostic process. The estimated growth rate has a remarkable seasonal cycle with minimum rates occurring in spring and maximum rates evident in autumn. More specifically, the growth rate derived from the meridional advection(surface heat flux) is positive(negative) throughout the year. Vertical diffusion generally makes a negative contribution to the evolution of growth rate and the magnitude of vertical entrainment represents the smallest contributor. Analysis indicates that the zonal advective feedback is regulated by the meridional immigration of the intertropical convergence zone, which approaches its southernmost extent in February and progresses to its northernmost location in September, and dominates the seasonal variation of the SST growth rate. 展开更多
关键词 SST growth rate intertropical convergence zone zonal advective feedback mixed layer depth ENSO seasonal variation
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Zonal activation of molecular carbon dioxide and hydrogen over dual sites Ni-Co-MgO catalyst for CO_(2) methanation:Synergistic catalysis of Ni and Co species
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作者 Zonglin Li Jianjun Chen +8 位作者 Yu Xie Junjie Wen Huiling Weng Mingxue Wang Jingyi Zhang Jinyan Cao Guocai Tian Qiulin Zhang Ping Ning 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2024年第4期213-225,共13页
An in-depth mechanism in zonal activation of CO_(2)and H2molecular over dual-active sites has not been revealed yet.Here,Ni-Co-MgO was rationally constructed to elucidate the CO_(2)methanation mechanism.The abundant s... An in-depth mechanism in zonal activation of CO_(2)and H2molecular over dual-active sites has not been revealed yet.Here,Ni-Co-MgO was rationally constructed to elucidate the CO_(2)methanation mechanism.The abundant surface nickel and cobalt components as active sites led to strong Ni-Co interaction with charge transfer from nickel to cobalt.Notably,electron-enriched Coδ-species participated in efficient chemisorption and activation of CO_(2)to generate monodentate carbonate.Simultaneously,plentiful available Ni0sites facilitated H2dissociation,thus CO_(2)and H2were smoothly activated at zones of Coδ-species and Ni0,respectively.Detailed in situ DRIFTS,quasi situ XPS,TPSR,and DFT calculations substantiated a new formate evolution mechanism via monodentate carbonate instead of traditional bidentate carbonate based on synergistic catalysis of Coδ-species and Ni0.The zonal activation of CO_(2)and H2by tuning electron behaviors of double-center catalysts can boost heterogeneous catalytic hydrogenation performance. 展开更多
关键词 Zonal activation CO_(2) methanation Dual active sites Synergistic effect
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Linear and Non-Linear Dynamics of Inertial Waves in a Rotating Cylinder with Antiparallel Inclined Ends
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作者 Mariya Shiryaeva Mariya Subbotina Stanislav Subbotin 《Fluid Dynamics & Materials Processing》 EI 2024年第4期787-802,共16页
This work is devoted to the experimental study of inertial wave regimes in a non-uniform rotating cylinder with antiparallel inclined ends.In this setting,the cross-section of the cylinder is divided into two regions ... This work is devoted to the experimental study of inertial wave regimes in a non-uniform rotating cylinder with antiparallel inclined ends.In this setting,the cross-section of the cylinder is divided into two regions where the fluid depth increases or decreases with radius.Three different regimes are found:inertial wave attractor,global oscillations(the cavity’s resonant modes)and regime of symmetric reflection of wave beams.In linear wave regimes,a steady single vortex elongated along the rotation axis is generated.The location of the wave’s interaction with the sloping ends determines the vortex position and the vorticity sign.In non-linear regimes several pairs of the triadic resonance subharmonics are detected simultaneously.The instability of triadic resonance is accompanied by the periodic generation of mean vortices drifting in the azimuthal direction.Moreover,the appearance frequency of the vortices is consistent with the low-frequency subharmonic of the triadic resonance.The experimental results shed light on the mechanisms of the inertial wave interaction with zonal flow and may be useful for the development of new methods of mixing. 展开更多
关键词 ROTATION inertial wave attractor triadic resonance zonal flow instability
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Recent Enhancement in Co-Variability of the Western North Pacific Summer Monsoon and the Equatorial Zonal Wind 被引量:1
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作者 Minmin WU Xugang PENG +3 位作者 Baiyang CHEN Lei WANG Jinwen WENG Weijian LUO 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2023年第9期1597-1616,共20页
The western North Pacific summer monsoon(WNPSM)is an important subcomponent of the Asian summer monsoon.The equatorial zonal wind(EZW)in the lower troposphere over the western Pacific may play a critical role in the e... The western North Pacific summer monsoon(WNPSM)is an important subcomponent of the Asian summer monsoon.The equatorial zonal wind(EZW)in the lower troposphere over the western Pacific may play a critical role in the evolution of the El Niño-Southern Oscillation(ENSO).The possible linkage between the EZW over the western Pacific and the offequatorial monsoonal winds associated with the WNPSM and its decadal changes have not yet been fully understood.Here,we find a non-stationary relationship between the WNPSM and the western Pacific EZW,significantly strengthening their correlation around the late 1980s/early 1990s.This observed shift in the WNPSM–EZW relationship could be explained by the changes in the related sea surface temperature(SST)configurations across the tropical oceans.The enhanced influence from the springtime tropical North Atlantic,summertime tropical central Pacific,and maritime continent SST anomalies may be working together in contributing to the recent intensified WNPSM–EZW co-variability.The observed recent strengthening of the WNPSM–EZW relationship may profoundly impact the climate system,including prompting more effective feedback from the WNPSM on subsequent ENSO evolution and bolstering a stronger biennial tendency of the WNPSM–ENSO coupled system.The results obtained herein imply that the WNPSM,EZW,ENSO,and the tropical North Atlantic SST may be closely linked within a unified climate system with a quasi-biennial rhythm occurring during recent decades,accompanied by a reinforcement of the WNPSM–ENSO interplay quite possibly triggered by enhanced tropical Pacific–Atlantic cross-basin interactions.These results highlight the importance of the tropical Atlantic cross-basin influences in shaping the spatial structure of WNPSM-related wind anomalies and the WNPSM–ENSO interaction. 展开更多
关键词 western North Pacific summer monsoon equatorial zonal wind interdecadal variability monsoon-ENSO interaction cross-basin interactions biennial variability
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面向汽车Zonal架构的TSN轻量级认证与授权通信框架
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作者 鲁睿其 谢国琪 +1 位作者 刘新忠 李仁发 《汽车工程》 EI CSCD 北大核心 2023年第6期944-953,共10页
汽车智能化需求推动了汽车电子电气(electrical/electronic,E/E)架构向基于时间敏感网络(time-sensitive networking,TSN)的区域(Zonal)架构演进,但网联化发展给数据传输带来了严重的信息安全问题。TSN标准所提供的流过滤器、流控门和... 汽车智能化需求推动了汽车电子电气(electrical/electronic,E/E)架构向基于时间敏感网络(time-sensitive networking,TSN)的区域(Zonal)架构演进,但网联化发展给数据传输带来了严重的信息安全问题。TSN标准所提供的流过滤器、流控门和流计量器3层信息防护模块本质上是一种边界防火墙技术,一旦边界被攻破,整个架构将暴露并因此瘫痪;此外,这种防护技术因存在多层处理而产生过多的计算和通信开销。本文提出一种面向汽车Zonal架构的TSN轻量级认证与授权通信框架,以去边界的方式实现了防劫持、防篡改及防监听的一体化防护方案。基于NXP车规级TSN交换芯片SJA1105Q(作为中央控制器)与NXP车规级SoC LS1028A(作为区域控制器)构建了Zonal架构原型平台,并将所开发的框架部署该原型平台,通过ProVerif工具验证了框架的安全性;基于原型平台的评估结果表明,所提框架在计算和通信开销方面均优于现有汽车信息安全通信框架。 展开更多
关键词 汽车Zonal架构 TSN 信息安全 认证与授权
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Analysis of Anomalous Enhancement in TEC and Electron Density in the China Region Prior to the 17 March 2015 Geomagnetic Storm Based on Ground and Space Observations 被引量:1
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作者 Xiaoyun CHENG Dongjie YUE +2 位作者 Changzhi ZHAI Yutian CHEN Xunzhe YIN 《Journal of Geodesy and Geoinformation Science》 CSCD 2023年第2期40-50,共11页
Total Electron Content(TEC)and electron density enhancement were observed on the day before 17 March 2015 great storm in the China Region.Observations from ground-and space-based instruments are used to investigate th... Total Electron Content(TEC)and electron density enhancement were observed on the day before 17 March 2015 great storm in the China Region.Observations from ground-and space-based instruments are used to investigate the temporal and spatial evolution of the pre-storm enhancement.TEC enhancement was observed from 24°N to 30°N after 10:00 UT at 105°E,110°E and 115°E longitudes on March 16.The maximum magnitude of TEC enhancement was more than 10 TECU and the maximal relative TEC enhancement exceeded 30%.Compared with geomagnetic quiet days,the electron density of Equatorial Ionization Anomaly(EIA)northern peak from Swarm A/C satellites on March 16 was larger and at higher latitudes.NmF2 enhanced during 11:30—21:00 UT at Shaoyang Station and increased by 200%at~16:00 UT.However,TEC and electron density enhancement were not accompanied by a significant change of hmF2.Most research has excluded some potential mechanisms as the main driving factors for storm-time density enhancements by establishing observational constraints.In this paper,we observed pre-storm enhancement in electron density at different altitudes and Equatorial Electrojet(EEJ)strength results derived from ground magnetometers observations suggest an enhanced eastward electric field from the E region probably played a significant role in this event. 展开更多
关键词 Equatorial Ionization Anomaly(EIA) electron density geomagnetic storm Total Electron Content(TEC) zonal electric field
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Variation in concentration of dissolved silicate in the Eastern Philippine deep sea
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作者 Ruixue XIA Qiang XIE +3 位作者 Weiqiang WANG Hongzhou XU Xuekun SHANG Yeqiang SHU 《Journal of Oceanology and Limnology》 SCIE CAS CSCD 2023年第4期1454-1463,共10页
Upper Circumpolar Deep Water(UCDW)and North Pacifi c Deep Water(NPDW)coexist in the upper deep layer(i.e.,with a 1.2-2.0-℃potential temperature range and a 2000-4100-dbar pressure range)of the Eastern Philippine Sea.... Upper Circumpolar Deep Water(UCDW)and North Pacifi c Deep Water(NPDW)coexist in the upper deep layer(i.e.,with a 1.2-2.0-℃potential temperature range and a 2000-4100-dbar pressure range)of the Eastern Philippine Sea.They have similar properties in potential temperature and salinity,while have a signifi cant diff erence in dissolved silicate.Based on the repeated observations along a 137°E transect from the World Ocean Database(WOD18),this study revealed the interannual variability of dissolved silicate in the upper deep layer of the Eastern Philippine Sea.Dissolved silicate increased in 1995,1996,2005,2006,and 2007,and decreased in 1997,2000,2001,2002,and 2004.Composition analysis showed that the large diff erence between positive and negative dissolved silicate anomalies occurred mainly at~15°N and north of 25°N,with the concentration reaching 4.25μmol/g.Further analysis indicated that the interannual dissolved silicate variability was related to the zonal current variation in the upper deep layer.The relatively strong(weak)westward current transport increased(decreased)NPDW to the Eastern Philippine Sea,thereby resulting in increased(decreased)dissolved silicate. 展开更多
关键词 interannual variability North Pacific deep water upper deep layer dissolved silicate zonal velocity variability
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Dynamic modelling and engineering simulation of fluid mechanics in water injectors
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作者 JIA Deli WEN Haoyang +3 位作者 SUN Fuchao WANG Quanbin YANG Qinghai FU Tao 《Petroleum Exploration and Development》 SCIE 2023年第5期1236-1245,共10页
To study the fluid dynamic response mechanism under the working condition of water injection well borehole,based on the microelement analysis of fluid mechanics and the classical theory of hydrodynamics,a fluid microe... To study the fluid dynamic response mechanism under the working condition of water injection well borehole,based on the microelement analysis of fluid mechanics and the classical theory of hydrodynamics,a fluid microelement pressure-flow rate relationship model is built to derive and solve the dynamic distribution of fluid pressure and flow rate in the space of well borehole.Combined with the production data of a typical deviated well in China,numerical simulations and analyses are carried out to analyze the dynamic distribution of wellbore pressure at different injection pressures and injection volumes,the delayed and attenuated characteristics of fluid transmission in tube,and the dynamic distribution of wellbore pressure amplitude under the fluctuation of wellhead pressure.The pressure loss along the wellbore has nothing to do with the absolute pressure,and the design of the coding and decoding scheme for wave code communication doesn’t need to consider the absolute pressure during injecting.When the injection pressure is constant,the higher the injection flow rate at the wellhead,the larger the pressure loss along the wellbore.The fluid wave signal delay amplitude mainly depends on the length of the wellbore.The smaller the tubing diameter,the larger the fluid wave signal attenuation amplitude.The higher the target wave code amplitude(differential pressure identification root mean square)generated at the same well depth,the greater the wellhead pressure wave amplitude required to overcome the wellbore pressure loss. 展开更多
关键词 zonal water injection wellbore fluid fluid mechanics dynamic response wireless communication
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Study of the Spatio-Temporal Variability of Rainfall in the Northern Region of Senegal
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作者 Aichétou Dia Diop Abdoul Karim Mbodji +8 位作者 El Hadji Deme Malick Wade Mahamat Adoum Moussa Abdoulaye Bouya Diop Younousse Biaye Djiby Sarr Abdou Karim Farota Aboubakary Diakhaby Bouya Diop 《Journal of Geoscience and Environment Protection》 2023年第4期1-14,共14页
Senegal is a country of the Sahel. In this region, most of the populations live from agro-pastoral activities. The northern zone of Senegal is strongly influenced by river cultures. And the dynamics of the Senegal Riv... Senegal is a country of the Sahel. In this region, most of the populations live from agro-pastoral activities. The northern zone of Senegal is strongly influenced by river cultures. And the dynamics of the Senegal River are dependent on rainfall. The rainfall in the area is very closely linked to the dynamics of the atmosphere. The study of the spatio-temporal variability of rainfall in the northern region of Senegal requires quality rainfall observation data. It includes the Ferlo and the Senegal River valley, in particular the regions of Louga (department of Linguère included), Saint-Louis (departments of Dagana and Podor included) and Matam. These stations have been defined since Le Borgne (1988). The difficulty of having quality rain observation data can be resolved by using more accessible and good quality satellite data. Using satellite data, namely MSWEP, CRU, TAMSAT, ARC and PERSIANN, we showed the return of precipitation that appeared in 2000 and the unimodal cycle of precipitation in our study area. These data were validated using the correlation coefficient, the bias, the RMSE and the Nash index with observation data from the Regional Study Center for the Improvement of Adaptation to Drought (CERASS). The CRU data is then retained. Thus, this study made it possible to show the zonal distribution of rainfall in the northern zone of Senegal. 展开更多
关键词 Rainfall in the Northern Region of Senegal Variability of Rainfall Satellite Data The Zonal Distribution of Rainfall
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基于SHIPFLOW的某大型集装箱船阻力预报与试验验证 被引量:5
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作者 卢雨 胡安康 +1 位作者 尹逊滨 田明琦 《中国造船》 EI CSCD 北大核心 2016年第2期22-30,共9页
以势流兴波阻力理论中的Rankine源方法为计算基础,利用SHIPFLOW软件模拟了某大型集装箱船的周围流场,考虑流体粘性及自由表面影响,预报了集装箱船的船模阻力。选择三种船体网格(FM,MM,CM)进行船体表面网格划分,采用势流理论与粘流理论... 以势流兴波阻力理论中的Rankine源方法为计算基础,利用SHIPFLOW软件模拟了某大型集装箱船的周围流场,考虑流体粘性及自由表面影响,预报了集装箱船的船模阻力。选择三种船体网格(FM,MM,CM)进行船体表面网格划分,采用势流理论与粘流理论的分区分步计算方式(ZONAL法),将数值计算的船舶总阻力值与船模试验值进行对比。计算结果表明网格划分形式MM的计算结果最为准确,同时也验证了SHIPFLOW软件求解技术的可靠性并提高了计算效率。最后选择MM网格划分形式,基于改造母型船法,对原球艏形式进行了改型,计算结果表明:改型球艏船型较原始船型具有更好的阻力性能,达到了船型优化的目的。 展开更多
关键词 SHIPFLOW 集装箱船 ZONAL法 船模试验 改型球艏
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N-S EQUATION CALCULATIONS ON MULTI-ELEMENT AIRFOILS WITH ZONAL PATCHED GRIDS 被引量:2
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作者 郭同庆 陆志良 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI 2003年第2期155-158,共4页
For a complex flow about multi-element airfoils a mixed grid method is set up. C-type grids are produced on each element′s body and in their wakes at first, O-type grids are given in the outmost area, and H-type grid... For a complex flow about multi-element airfoils a mixed grid method is set up. C-type grids are produced on each element′s body and in their wakes at first, O-type grids are given in the outmost area, and H-type grids are used in middle additional areas. An algebra method is used to produce the initial grids in each area. And the girds are optimized by elliptical differential equation method. Then C-O-H zonal patched grids around multi-element airfoils are produced automatically and efficiently. A time accurate finite-volume integration method is used to solve the compressible laminar and turbulent Navier-Stokes (N-S) equations on the grids. Computational results prove the method to be effective. 展开更多
关键词 multi-element airfoils zonal patched grids finite-volume method N-S equations
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Analysis of Gardening Based on the Unique Zonal Water System of Slender West Lake 被引量:1
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作者 陶欣 吴涛 《Journal of Landscape Research》 2009年第12期77-81,共5页
Yangzhou Slender West Lake is narrow in shape. It is 4.3 km in total length with the width of about 100 m. It is a typical zonal water system. Through the research of its spatial structure, space sequence and view bor... Yangzhou Slender West Lake is narrow in shape. It is 4.3 km in total length with the width of about 100 m. It is a typical zonal water system. Through the research of its spatial structure, space sequence and view borrowing the garden bridges of Yangzhou Slender West Lake, the unique gardening method of zonal water system was expatiated. 展开更多
关键词 ZONAL water system Multi VANISHING points Space sequence GARDEN bridge WEST LAKE
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复多元正态总体球性检验似然比准则的精确分布 被引量:1
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作者 龚力强 王剑侠 《广州大学学报(自然科学版)》 CAS 2002年第2期1-4,共4页
讨论了r个复多元正态总体中检验假设H :μ1=μ2 =… =μr=μ0 ;Σ1 =Σ2 =… =Σr=σ2 I的检验问题 。
关键词 复元多正态总体球性检验 似然比准则 精确分布 Zonal多项式 Lauricella超几何函数 H-函数 似然比统计量
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室内气流模拟方法比较及一种新的Zonal模型方法研究 被引量:2
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作者 张国强 LIN Yi HAGHIGHAT Fariborz 《应用基础与工程科学学报》 EI CSCD 2000年第3期291-300,共10页
比较了室内气流分布模拟的常用方法及其优缺点 ,指出 Zonal模型方法是一种有前途的方法 .研究了一种基于网格基准压力差概念的 Zonal模型方法 .通过对多种通风条件的模拟表明 ,该方法应用简单 ,节省计算机机时 。
关键词 室内气流分布 数值模拟 Zonal模型 CFD模型 基准压力
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土地开垦年限对研究土地退化的作用——以吉林省镇赉县为例
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作者 吕妍 张树文 杨久春 《安徽农业科学》 CAS 北大核心 2011年第33期20699-20702,共4页
以吉林省镇赉县为例,从历史资料中获取了各个屯落的开垦年限进行分析。在ArcGIS环境下,对土地开垦年限进行插值,对比插值结果和镇赉县的DEM,并将土壤类型与插值结果进行zonal histogram分析,得出镇赉县各地的平均开垦年限,及每种土壤类... 以吉林省镇赉县为例,从历史资料中获取了各个屯落的开垦年限进行分析。在ArcGIS环境下,对土地开垦年限进行插值,对比插值结果和镇赉县的DEM,并将土壤类型与插值结果进行zonal histogram分析,得出镇赉县各地的平均开垦年限,及每种土壤类型出现于每个开垦年限的可能性大小,从而分析出每种土壤类型被开垦的先后顺序是以开垦的难易程度决定的,并推出开垦顺序与土壤类型没有显著关系的结论。并根据每种土壤类型的开垦年限,得出栗钙土的土地退化程度可能较小,黑钙土、冲积土、草甸土、淡黑钙土、风沙土、碱土的土地退化程度都较大。 展开更多
关键词 土地退化 开垦年限 插值 土壤类型 ZONAL Histogram分析 ARCGIS
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生长曲线模型中参数的检验问题
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作者 龚力强 徐圣兵 《广州大学学报(自然科学版)》 CAS 2006年第1期1-7,共7页
讨论了生长曲线模型中关于原假设为H0:Λ=σ2I,μ=μ0的检验问题,并以2-分布为基础的级数形式给出了似然比检验统计量在以下两类与原假设相接近的备择假设下的渐近分布.K1:I-ηΛ-1=M2Ω,η-1/2(μ1-μ0)=M-1/2δ;K2:I-η-1Λ=M2Q,η-1... 讨论了生长曲线模型中关于原假设为H0:Λ=σ2I,μ=μ0的检验问题,并以2-分布为基础的级数形式给出了似然比检验统计量在以下两类与原假设相接近的备择假设下的渐近分布.K1:I-ηΛ-1=M2Ω,η-1/2(μ1-μ0)=M-1/2δ;K2:I-η-1Λ=M2Q,η-1/2(μ1-μ0)=M-1/2δ. 展开更多
关键词 似然比检验 分布 Zonal多项式
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The Realization of Ecological Ideas of Economic Gardens——A Case Study of "Red ribbon" Park in Qinhuangdao City
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作者 王颖 孔繁德 《Journal of Landscape Research》 2009年第3期17-20,共4页
The aim of this study is to analyze the ecological ideas of local habitat conservation,least intervention and concise ecological design in the design of Red Ribbon Park,and meanwhile put forward the suggestion that th... The aim of this study is to analyze the ecological ideas of local habitat conservation,least intervention and concise ecological design in the design of Red Ribbon Park,and meanwhile put forward the suggestion that the ecosystem health level of Tanghe River should be promoted as a whole. 展开更多
关键词 Tanghe River ZONAL PARK Red RIBBON ECOLOGICAL ideas ECONOMIC gardens ECOSYSTEM health
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复多元GAUSSIAN模型中参数的检验问题
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作者 龚力强 王剑侠 《广州大学学报(自然科学版)》 CAS 2003年第1期5-10,共6页
讨论q个复多元正态总体中关于假设H :Σ1=… =Σq=σ2 I ,μ1=… =μq=μ0 的检验问题 ,并以 χ2 -分布为基础的级数形式给出了在与原假设相接近的某些备择假设下似然比统计量的非零渐近分布 .
关键词 复多元GAUSSIAN模型 假设检验 Zonal多项式 复多元正态分布 似然比统计量 参数检验
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急性区域性隐匿性外层视网膜病变误诊为视神经视网膜病变1例
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作者 许畅 毛晓春 《临床眼科杂志》 2016年第3期214-214,共1页
急性区域性隐匿性外层视网膜病变(acute zonal occult outer retinopathy,AZOOR)是一组急性发作、眼底表现不明显,以单个或多个区域视网膜外层功能障碍为特征的症候群。其早期可仅表现为视力下降,传统的检测手段,如眼底彩色照相、视... 急性区域性隐匿性外层视网膜病变(acute zonal occult outer retinopathy,AZOOR)是一组急性发作、眼底表现不明显,以单个或多个区域视网膜外层功能障碍为特征的症候群。其早期可仅表现为视力下降,传统的检测手段,如眼底彩色照相、视野、视网膜电图及荧光素眼底血管造影(FFA)等在AZOOR的诊断及随访中均存在一定的局限性易误诊、漏诊。 展开更多
关键词 视网膜病变 视网膜电图 隐匿性 OCCULT 视野检查 黄斑中心凹反光 光感受器细胞层 性易 ZONAL 眼底照相
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多元正态总体期望和协方差同时检验的问题
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作者 龚力强 《广州大学学报(自然科学版)》 CAS 2004年第3期193-199,共7页
讨论了q个多元正态总体中关于统计假设H0:μ1=μ2=…=μq=μ0,Σ1=Σ2=…=Σq=σ2I的检验问题,并以χ2 分布为基础的级数形式给出了似然比检验统计量的零分布及在与原假设相接近的某些备择假设下非零分布的一个渐近展开式.
关键词 似然比检验 Zonal多项式
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