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余商法 被引量:5
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作者 王元和 《中国科教创新导刊》 2009年第30期60-61,共2页
本文介绍余商法的步骤和素数的判断以及素数的分类。
关键词 余商法 可能有的余数 商位位数 商位和 素数节 循环 取为整数
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Effects of Nitrogen Application on Osmotic Adjustmentof Ramie (Boehmeria nivea L.) with Different NitrogenEfficiency 被引量:2
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作者 CHEN Ji-kang GAO Gang +4 位作者 YU Chun-ming CHEN Ping CHEN Kun-mei WANG Xiao-fei ZHU Ai-guo 《Agricultural Science & Technology》 CAS 2019年第6期14-21,27,共9页
Ramie (Boehmeria nivea L.) is one of the most important fiber crops and biomass materials. However, previous studies showed that ramie presented a very low nitrogen agronomy efficiency (NAE, 23.2%~27.8%) in traditiona... Ramie (Boehmeria nivea L.) is one of the most important fiber crops and biomass materials. However, previous studies showed that ramie presented a very low nitrogen agronomy efficiency (NAE, 23.2%~27.8%) in traditional farming, and the nitrogen fertilizer was applied excessively in ramie field. Plant osmotic adjustment (OA) responses to environmental stresses positively and exhibits improvements in plant tolerance. Whereas results varied due to the complexity of plant-environment interactions and lack of insights of specific species. In order to improve ramie production through osmoregulation, our current study investigated the role of nitrogen application and osmotic adjustment in improving the growth and yield in two varieties of ramie (H2000-03 and Ceheng Jiama) with contrasting nitrogen use efficiency (NUE) grown at 5 different N rates including N0, N6, N9, N12 and N15;0, 6, 9, 12 and 15 mmol/L N, respectively. The results showed that ramie adapted to different nitrogen rates through OA and significant differences of osmolyte content between varieties only presented at the particular growth stage. Obvious inflexion of yield, osmolyte content involving proline, soluble protein (SP), soluble sugar (SS) and malonaldehyde (MDA);nitrogen sensitive index (NSI) and comprehensive evaluation (D) in both varieties were observed. Our results recommended that the overall lifting of OA at a lower N level and at the proper growth stage would be a reasonable approach for improving ramie NUE. 展开更多
关键词 RAMIE Nitrogen use efficiency CHLOROPHYLL Osmotic adjustment Nitrogen sensitive index
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Characterizing Spatial Patterns of Precipitation Based on Corrected TRMM_3B_(43) Data over the Mid Tianshan Mountains of China 被引量:9
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作者 JI Xuan CHEN Yunfang 《Journal of Mountain Science》 SCIE CSCD 2012年第5期628-645,共18页
The poor distribution of meteorological stations results in a limited understanding of the precipitation pattern in the Tianshan Mountains. The spatial patterns of precipitation over the mid Tianshan Mountains were ch... The poor distribution of meteorological stations results in a limited understanding of the precipitation pattern in the Tianshan Mountains. The spatial patterns of precipitation over the mid Tianshan Mountains were characterized based on the TRMM 3B43 monthly precipitation data. By comparing satellite estimates with observed data, it shows that TRMM 3B43 data underestimate the precipitation in mountain region. Regression models were developed to improve the TRMM 3B43 data, using geographic location and topographic variables extracted from DEM using GIS technology. The explained variance in observed precipitation was improved from 64% (from TRMM 3B43 products alone) to over 82% and the bias reduced by over 30% when location and topographic variables were added. We recalculated all the TRMM 3B43 monthly precipitation grids for the period 1998 to 2009 using the best regression models, and then studied the variation patterns of precipitation over the mid Tianshan Mountains. The results are well explained by a general understanding of the patterns of precipitation and orographic effects. This indicated that the Tianshan Mountains strongly influences the amount and distribution of precipitation in the region. This is highlighted by the confinement of the precipitation maxima to the windward (northern slope). And complex vertical changes in the provenance and distribution of precipitation, like that a negative increasing rate of precipitation in the vertical direction exists in the north but does not in south. The results have also revealed large gradients and different patterns in seasonal precipitation that are not simply related to elevation, the distribution of precipitation may also be affected by other seasonal factors such as the sources of moist air, wind direction and temperature. 展开更多
关键词 Spatial pattern PRECIPITATION TianshanMountains TRMM
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哥徳巴赫猜想之证明
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作者 张继波 《数学学习与研究》 2015年第1期121-122,共2页
问题的提出;大于4的偶数,均可等于两个素数之和.哥德巴赫所担心的问题是:当一个偶数充分大时,是否还会不会有充分大的两个素数之和用来等于该偶数.实际上,担心是没有必要的,可以肯定地说,当一个偶数越大时,而与其该偶数相等的素数对就... 问题的提出;大于4的偶数,均可等于两个素数之和.哥德巴赫所担心的问题是:当一个偶数充分大时,是否还会不会有充分大的两个素数之和用来等于该偶数.实际上,担心是没有必要的,可以肯定地说,当一个偶数越大时,而与其该偶数相等的素数对就会越多。 展开更多
关键词 加全偶数 等价式 互换式 取值 素数连续乘积
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Analyses of local ingredients and dishes on menus of the Budapest-Middle-Danube touristic region
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作者 Denes Sandor 《Chinese Business Review》 2010年第8期37-45,共9页
The background of the study is based on previous studies dealing with the areas of Transdanubia of Hungary. Those works have proved the hypothesis of author that local ingredients and dishes represent minimum role on ... The background of the study is based on previous studies dealing with the areas of Transdanubia of Hungary. Those works have proved the hypothesis of author that local ingredients and dishes represent minimum role on menus. The question is how similar or different the choice of menus of Budapest-Middle-Danube compared with the previously examined areas of Hungary. There can be another question about the usage of local ingredients available near to the catering units. This piece of work has studied 79 menus of Budapest-Middle-Danube, Hungary. The material was collected from different types of restaurants, small restaurants (vendeglo in Hungarian) and roadside restaurants (csarda in Hungarian). The method of the work was on the one hand, data collecting, and on the other hand, examination of the differences between the catering units in details: the number of dishes, the right order of dishes, the appearance of local ingredients and dishes, the consideration of seasonality, the usage of different cooking methods and group of dishes. The study reflects the main problems of countryside restaurants in Hungary. Only minimum number of dishes could be connected to local dishes out of more than thousands. All in all, dishes are not as precise and perfect as the "old ones", so that is why it is important for every expert keep the traditions alive in daily routines and strategic mean too. 展开更多
关键词 menu analysis local raw materials and dishes Budapest-Middle-Danube touristic region
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Uncertainty analysis of hydrological processes based on ARMA-GARCH model 被引量:7
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作者 WANG HongRui GAO Xiong +1 位作者 QIAN LongXia YU Song 《Science China(Technological Sciences)》 SCIE EI CAS 2012年第8期2321-2331,共11页
Uncertainty analysis and risk analysis are two important areas of modern water resource management,in which accurate variance estimation is required.The traditional runoff model is established under the assumption tha... Uncertainty analysis and risk analysis are two important areas of modern water resource management,in which accurate variance estimation is required.The traditional runoff model is established under the assumption that the variance is a constant or it changes with the seasons.However,hydrological processes in the real world are often heteroscedastic,which can be tested by McLeod-Li test and Engle Lagrange multiplier test.In such cases,the GARCH model of hydrological processes is established in this article.First,the seasonal factors in the sequence are removed.Second,the traditional ARMA model is established.Then,the GARCH model is used to correct the residual.At last,the daily runoff data in 1949-2001 of Yichang Hydrological Station is taken to be an example.The result shows that compared to the traditional ARMA model,the GARCH model has the ability to predict more accurate confidence intervals under the same confidence level. 展开更多
关键词 runoff forecast conditional heteroscedasticity GARCH model uncertainty analysis McLeod-Li test Engle Lagrange multiplier test
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