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一个适用于区域性大气环境模拟的大气光化学模式 被引量:13
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作者 何东阳 黄美元 《环境科学学报》 CAS CSSCI CSCD 北大核心 1992年第2期182-192,共11页
根据“计数物种”法对光化学反应机制的分析,建立了一个适用于区域性光化学反应模拟的模式,该模式能较好地模拟出NO_x、O_3及H_2O_2等大气光化学污染物的变化,在保证模拟准确性的同时,该模式形式简单,有利于在实际大气环境质量模拟中应用.
关键词 光化学反应 计数物种 NOx O3
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Experimental Studies on Debris Flow with Logs Focusing on Specific Weight Difference of Log Species 被引量:2
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作者 Haruki WATABE Takahiro ITOH +1 位作者 Kazuhiko KAITSUKA Shigeki NISHIMURA 《Journal of Mountain Science》 SCIE CSCD 2013年第2期315-325,共11页
There are many experimental approaches,field investigations and numerical calculations for movements of woods in a clear water and debris flow.However,kinematic conditions for accumulated logs and the interactions bet... There are many experimental approaches,field investigations and numerical calculations for movements of woods in a clear water and debris flow.However,kinematic conditions for accumulated logs and the interactions between a main flow and logs have not been fully evaluated.Mitigations for woods need taking into account the characteristics of tree species such as conifer and broad-leaf trees and of shapes such as root swells and crown.In the present study,we focus on the differences in specific weight of conifer and broad-leaf trees with some moisture in a sediment-water mixture flow with narrow flow width,and consider that conifer and broad-leaf tree are floating and submerged solid phase,respectively.Flume tests are conducted in steady flow of clear and debris flow over a rigid bed in order to evaluate conifer and broad-leaf tree movement in clear water and debris flow.Experimental data indicates that dimensionless transverse diffusion coefficient can be 0.1 to 0.4 and 0.3 to 0.9 in flow direction.Those diffusive characteristics seem to be independent of Reynolds number and Froude number,but dependent of bed slope,i.e.,gravity,though detailed considerations are needed to discuss about flow characteristics such as spatial eddy structures,momentum transfer induced by interactions of logs and so on. 展开更多
关键词 Debris flow DRIFTWOOD Specificweight LOG Flume test
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Simultaneous Selection for Yield and Stability in Sugarcane Using Parametric Statistics
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作者 Marvellous M. Zhou Munashe D. Shoko 《Journal of Agricultural Science and Technology(B)》 2012年第4期400-410,共11页
Sugarcane advanced variety trials are planted across several locations and harvested for several crop-years to determine genotype by environment interaction and yield stability. Previous studies describe methods for s... Sugarcane advanced variety trials are planted across several locations and harvested for several crop-years to determine genotype by environment interaction and yield stability. Previous studies describe methods for simultaneous screening for yield and stability but did not use parametric statistical tests for comparing genotypes. The objective of this study was to describe a parametric statistical method for simultaneous screening of sugarcane genotypes for yield and stability. Data from 26 crops were collected from trials established at five locations and harvested in the plant, first, second, third and fourth ratoon crops. The mixed procedure of SAS was used for data analysis. The intercept and slope were used to represent yield and stability, respectively. There were significant (P 〈 0.05) differences in yield and stability among the genotypes. Test genotypes were classified into groups of genotypes that produced high yield, or high stability or both. The method provides fast statistical tests for simultaneous screening for yield and stability. The method was also used to compare two genotypes, an application for variety choice at time of release. 展开更多
关键词 STABILITY PARAMETRIC simultaneous screening advanced variety trials.
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The BPP program for species tree estimation and species delimitation 被引量:17
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作者 Ziheng YANG 《Current Zoology》 SCIE CAS CSCD 2015年第5期854-865,共12页
This paper provides an overview and a tutorial of the BPP program, which is a Bayesian MCMC program for analyzing multi-locus genomic sequence data under the multispecies coalescent model. An example dataset of five n... This paper provides an overview and a tutorial of the BPP program, which is a Bayesian MCMC program for analyzing multi-locus genomic sequence data under the multispecies coalescent model. An example dataset of five nuclear loci from the East Asian brown frogs is used to illustrate four different analyses, including estimation of species divergence times and population size parameters under the multispecies coalescent model on a fixed species phylogeny (A00), species tree estimation when the assignment and species delimitation are fixed (A01), species delimitation using a fixed guide tree (A10), and joint species delimitation and species-tree estimation or unguided species delimitation (A11). For the joint analysis (A11), two new priors are introduced, which assign uniform probabilities for the different numbers of delimited species, which may be useful when assignment, species delimitation, and species phylogeny are all inferred in one joint analysis. The paper ends with a discussion of the assumptions, the strengths and weaknesses of the BPP analysis [Current Zoology 61 (5): 854-865, 2015]. 展开更多
关键词 BPP MCMC Multispecies coalescent Species delimitation Species tree
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Comparing children's Homo sapiens and chimpanzees' Pan troglodytes quantity judgments of sequentially presented sets of items
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作者 Michael J. BERAN Julie S. JOHNSON-PYNN Christopher READY 《Current Zoology》 SCIE CAS CSCD 北大核心 2011年第4期419-420,421-428,共10页
We presented a quantity judgment task that involved comparing two sequentially presented sets of items to preschoolers and chimpanzees using nearly identical procedures that excluded verbal instructions to children. T... We presented a quantity judgment task that involved comparing two sequentially presented sets of items to preschoolers and chimpanzees using nearly identical procedures that excluded verbal instructions to children. Trial difficulty in this task reflected the ratio difference between sets of discrete items where larger ratios (e.g., 0.80 as from comparing 4 to 5) were more difficult than smaller ones (e.g., 0.50 as from comparing 4 to 8). Children also completed verbal-based tasks probing the relationskip between counting proficiency and performance on the quantity judgment task of sequentially presented identical sized items. Both species' performance was best when ratios between comparison sets were small regardless of set size in all types of tasks. Generally, chimpanzees and older children performed better than younger children except at larger ratios. Children's counting proficiency was not related to success in choosing the larger of two quantities of identical-sized items. These results indicate that chimpanzees and children share an approximate number sense that is reflected through analog magnitude estimation when comparing quantities [Current Zoology 57 (4): 419-428, 2011]. 展开更多
关键词 Numerical cognition Quantity judgments CHILDREN CHIMPANZEES Pan troglodytes
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