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稻粉虱发生及空间数量分布研究 被引量:3
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作者 符明龙 王云仙 +3 位作者 商晗武 谢淑玲 张春芬 谢秉相 《浙江农业学报》 CSCD 2000年第1期16-19,共4页
对稻粉虱的寄主范围、不同生境下的发生及空间数量分布作了调查研究。结果表明,稻粉虱在浙江苍南稻区的寄主为水稻、甘蔗、玉米3 种禾本科作物及稗草、千金子等13 种禾本科杂草,该虫在双季稻区发生显著重于单季稻区,半山区稻田为... 对稻粉虱的寄主范围、不同生境下的发生及空间数量分布作了调查研究。结果表明,稻粉虱在浙江苍南稻区的寄主为水稻、甘蔗、玉米3 种禾本科作物及稗草、千金子等13 种禾本科杂草,该虫在双季稻区发生显著重于单季稻区,半山区稻田为其最适宜的生境。稻粉虱成虫有喜于嫩绿、隐蔽、生长旺盛的植株叶片上产卵的习性,不同虫态在稻株叶片上的垂直分布及在不同生育期分蘖之间的分布与其产卵习性有明显相关。 展开更多
关键词 稻粉虱 寄主 空间数量分布 发生规律 预测预报
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鞭角华扁叶蜂滞育幼虫空间数量分布的研究 被引量:1
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作者 陈绘画 崔相富 郑永祥 《林业科学研究》 CSCD 北大核心 2001年第5期503-508,共6页
运用人工神经网络方法和空间趋势面分析方法对鞭角华扁叶蜂滞育幼虫的数量与其所处的空间位置之间的关系进行研究 ,创建鞭角华扁叶蜂滞育幼虫空间数量分布的 BP网络模型和三次趋势面模型。结果表明 :建立的 BP网络模型模拟不同空间位置... 运用人工神经网络方法和空间趋势面分析方法对鞭角华扁叶蜂滞育幼虫的数量与其所处的空间位置之间的关系进行研究 ,创建鞭角华扁叶蜂滞育幼虫空间数量分布的 BP网络模型和三次趋势面模型。结果表明 :建立的 BP网络模型模拟不同空间位置的鞭角华扁叶蜂滞育幼虫数量具有较高的拟合精度 ,当隐层神经元数为 12个时 ,其平均模拟精度为 96.90 % ,预留的 2 0组样本的平均预测精度为 92 .35 % ;而三次趋势面模型的平均模拟精度为 93.0 1% ,预留的 2 0组样本的平均预测精度为 93.2 4 %。 展开更多
关键词 人工神经网络 BP算法 鞭角华扁叶蜂滞育幼虫 空间格局 空间数量分布
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Quality Control and Analysis of Global Gauge-Based Daily Precipitation Dataset from 1980 to 2009 被引量:3
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作者 NIE Su-Ping LUO Yong +3 位作者 LI Wei-Ping WU Tong-Wen SHI Xue-Li WANG Zai-Zhi 《Advances in Climate Change Research》 2012年第1期45-53,共9页
A series of quality control(QC) procedures were performed on a gauge-based global daily precipitation dataset from the Global Telecommunication System(GTS) for the period 1980-2009.A new global daily precipitation(NGD... A series of quality control(QC) procedures were performed on a gauge-based global daily precipitation dataset from the Global Telecommunication System(GTS) for the period 1980-2009.A new global daily precipitation(NGDP) dataset was constructed by applying those QC procedures to eliminate erroneous records.The NGDP dataset was evaluated using the NOAA Climate Prediction Center Merged Analysis of Precipitation(CMAP) and the Global Precipitation Climatology Project(GPCP) precipitation datasets.The results showed that the frequency distribution and spatial distribution pattern of NGDP had a nice match with those from the CMAP and GPCP datasets.The global mean correlation coefficients with the CMAP and GPCP data increased from 0.24 for original GTS precipitation data to about 0.70 for NGDP data.Correspondingly,the root mean square errors(RMSE) decreased from 12 mm per day to 1 mm per day.The interannual variabilities of NGDP monthly precipitation are consistent with the CMAP and GPCP datasets in Asia.Meanwhile,the seasonal variabilities for most land areas on the Earth of NGDP dataset are also consistent with the CMAP and GPCP precipitation products. 展开更多
关键词 global surface weather report data GTS data daily precipitation quality control
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Some Fixed Point Theorems on Nonarchimedean Menger Probabilistic Metrie Space
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作者 毛宝瑜 陈汝栋 《Chinese Quarterly Journal of Mathematics》 CSCD 1993年第2期50-55,共6页
In this paper,we have given a fixed point theorem for mapping sequence and mapping pair on nonarchimedean Mengen Probabilistic Metric space.A special case of its inference is an extension of results of reference [5-6].
关键词 nonarchimedean Mengen Probabilistc metnc space common fixed point.
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Robust estimation in inverse problems via quantile coupling 被引量:2
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作者 TIAN MaoZai 《Science China Mathematics》 SCIE 2012年第5期1029-1041,共13页
In this article we consider a sequence of hierarchical space model of inverse problems.The underlying function is estimated from indirect observations over a variety of error distributions including those that are hea... In this article we consider a sequence of hierarchical space model of inverse problems.The underlying function is estimated from indirect observations over a variety of error distributions including those that are heavy-tailed and may not even possess variances or means.The main contribution of this paper is that we establish some oracle inequalities for the inverse problems by using quantile coupling technique that gives a tight bound for the quantile coupling between an arbitrary sample p-quantile and a normal variable,and an automatic selection principle for the nonrandom filters.This leads to the data-driven choice of weights.We also give an algorithm for its implementation.The quantile coupling inequality developed in this paper is of independent interest,because it includes the median coupling inequality in literature as a special case. 展开更多
关键词 inverse problem robust estimation oracle inequalities quantile coupling inequalities heavy-tailed distributions hierarchical sequence space model
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Spatial distribution of 10m firn temperature in the Antarctic Ice Sheet
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作者 WANG YeTang1,3 & HOU ShuGui2,3 1 Shandong Marine Fisheries Research Institute,Yantai 264006,China 2 MOE,Key Laboratory for Coast and Island Development,School of Geographic and Oceanographic Sciences,Nanjing University,Nanjing 210093,China 3State Key Laboratory of Cryospheric Science,Cold and Arid Regions Environmental and Engineering Research Institute,Chinese Academy of Sciences,Lanzhou 730000,China 《Science China Earth Sciences》 SCIE EI CAS 2011年第5期655-666,共12页
A database of Antarctic 10 m firn temperature was constructed using available borehole temperature measurements with data quality control to extend knowledge of Antarctic climate. Slopes from a high-resolution digital... A database of Antarctic 10 m firn temperature was constructed using available borehole temperature measurements with data quality control to extend knowledge of Antarctic climate. Slopes from a high-resolution digital elevation model and the main ice divide were used to delineate main drainage sectors across Antarctica. In each drainage sector, a quantitative relationship between temperature and latitude, longitude and altitude was established using available tim temperature data. Quantitative relationships incorporating other factors affecting Antarctic air temperature such as atmospheric circulation and small-scale to- pography were used to derive a 10-km resolution grid map of surface temperature. The resulting temperature patterns presented a reasonable depiction of both large and small-scale variations in Antarctic 10 m firn temperature. This map is useful for many spatial variation studies, Antarctic ice sheet models, and comparison with satellite-derived temperature data and outputs of atmospheric general circulation models. 展开更多
关键词 ANTARCTICA 10 m firn temperature spatial distribution
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