An L（2, 1）-labeling of a graph G is a function f from the vertex set V（G） to the set of all nonnegative integers such that ｜f（x） - f（y）｜ 〉 2 if d（x, y） = 1 and ｜f（x）-f（y）｜ ≥ 1 ifd（x, y） = 2. The ...An L（2, 1）-labeling of a graph G is a function f from the vertex set V（G） to the set of all nonnegative integers such that ｜f（x） - f（y）｜ 〉 2 if d（x, y） = 1 and ｜f（x）-f（y）｜ ≥ 1 ifd（x, y） = 2. The L（2, 1）-labeling number λ（G） of G is the smallest number k such that G has an L（2, 1）-labeling with max{f（v） ： v ∈ V（G）} = k. We study the L（3, 2, 1）-labeling which is a generalization of the L（2, 1）-labeling on the graph formed by the （Cartesian） product and composition of 3 graphs and derive the upper bounds of λ3（G） of the graph.展开更多
数据采集器通道误差是自动气象站观测系统误差来源的重要组成部分,直接影响自动站各要素观测数据的准确性,其与温、湿、压、风等各气象要素传感器误差的合成构成了自动气象站误差。在稳定的实验室环境条件下,利用高精度测量仪表,通过对...数据采集器通道误差是自动气象站观测系统误差来源的重要组成部分,直接影响自动站各要素观测数据的准确性,其与温、湿、压、风等各气象要素传感器误差的合成构成了自动气象站误差。在稳定的实验室环境条件下,利用高精度测量仪表,通过对多台CAWS600型采集器进行精确测量,得到自动站采集器各气象要素通道误差的校准数据。对温、湿、压、风等要素的自动测量系统(传感器和采集器)误差分析结果表明,自动站误差等于传感器误差与采集器通道误差之和。此外,采集器各主要通道的误差存在一定的分布规律:有10台采集器气温通道误差≤0.1℃,主要分布在-0.1~0.1℃,所占比例为77%;有3台采集器通道误差>0.15℃而≤0.20℃,所占比例为23%。在600-1090 h Pa量程内,气压通道误差主要分布在-0.10~0.10 h Pa;风向、湿度通道误差较小,误差值相近,方向较一致,风向通道误差≤1°,湿度通道误差≤1%。展开更多
The two-dimensional cellular detonation propagating in a channel with area-changing cross section was numerically simulated with the dispersion-controlled dissipative scheme and a detailed chemical reaction model. Eff...The two-dimensional cellular detonation propagating in a channel with area-changing cross section was numerically simulated with the dispersion-controlled dissipative scheme and a detailed chemical reaction model. Effects of the flow ex-pansion and compression on the cellular detonation cell were investigated to illus-trate the mechanism of the transverse wave development and the cellular detona-tion cell evolution. By examining gas composition variations behind the leading shock,the chemical reaction rate,the reaction zone length,and thermodynamic parameters,two kinds of the abnormal detonation waves were identified. To explore their development mechanism,chemical reactions,reflected shocks and rarefac-tion waves were discussed,which interact with each other and affect the cellular detonation in different ways.展开更多
文摘An L（2, 1）-labeling of a graph G is a function f from the vertex set V（G） to the set of all nonnegative integers such that ｜f（x） - f（y）｜ 〉 2 if d（x, y） = 1 and ｜f（x）-f（y）｜ ≥ 1 ifd（x, y） = 2. The L（2, 1）-labeling number λ（G） of G is the smallest number k such that G has an L（2, 1）-labeling with max{f（v） ： v ∈ V（G）} = k. We study the L（3, 2, 1）-labeling which is a generalization of the L（2, 1）-labeling on the graph formed by the （Cartesian） product and composition of 3 graphs and derive the upper bounds of λ3（G） of the graph.
文摘数据采集器通道误差是自动气象站观测系统误差来源的重要组成部分,直接影响自动站各要素观测数据的准确性,其与温、湿、压、风等各气象要素传感器误差的合成构成了自动气象站误差。在稳定的实验室环境条件下,利用高精度测量仪表,通过对多台CAWS600型采集器进行精确测量,得到自动站采集器各气象要素通道误差的校准数据。对温、湿、压、风等要素的自动测量系统(传感器和采集器)误差分析结果表明,自动站误差等于传感器误差与采集器通道误差之和。此外,采集器各主要通道的误差存在一定的分布规律:有10台采集器气温通道误差≤0.1℃,主要分布在-0.1~0.1℃,所占比例为77%;有3台采集器通道误差>0.15℃而≤0.20℃,所占比例为23%。在600-1090 h Pa量程内,气压通道误差主要分布在-0.10~0.10 h Pa;风向、湿度通道误差较小,误差值相近,方向较一致,风向通道误差≤1°,湿度通道误差≤1%。
文摘The two-dimensional cellular detonation propagating in a channel with area-changing cross section was numerically simulated with the dispersion-controlled dissipative scheme and a detailed chemical reaction model. Effects of the flow ex-pansion and compression on the cellular detonation cell were investigated to illus-trate the mechanism of the transverse wave development and the cellular detona-tion cell evolution. By examining gas composition variations behind the leading shock,the chemical reaction rate,the reaction zone length,and thermodynamic parameters,two kinds of the abnormal detonation waves were identified. To explore their development mechanism,chemical reactions,reflected shocks and rarefac-tion waves were discussed,which interact with each other and affect the cellular detonation in different ways.
