针对目前尚未存在有效的中文文本纠错软件测试用例最小化方法的情况,设计了两种中文文本纠错软件测试用例集最小化方法:基于多目标遗传算法的中文文本纠错软件测试用例集最小化方法(Minimization Method based on Multi-objective Genet...针对目前尚未存在有效的中文文本纠错软件测试用例最小化方法的情况,设计了两种中文文本纠错软件测试用例集最小化方法:基于多目标遗传算法的中文文本纠错软件测试用例集最小化方法(Minimization Method based on Multi-objective Genetic Algorithm of Test case for Chinese text error Correction Software,MMG-CCS)和基于TextRank模型的中文文本纠错软件测试用例最小化方法(Minimization Method based on TextRank of Test case for Chinese text error Correction Software,MMT-CCS).MMG-CCS基于问题特点设计了一种中文文本纠错软件测试用例集覆盖度模型,并将测试用例集大小及覆盖度作为目标函数,为了高效求解该问题,MMG-CCS同时对遗传算子进行了改进.此外,MMT-CCS方法能将测试用例集最小化问题映射为图解问题,并根据问题特点对TextRank模型进行了针对性改进.实验结果表明,MMG-CCS和MMT-CCS对测试用例集的缩减程度高,且在不同中文文本纠错软件上对于不同中文文本纠错软件测试用例集均能保持相同的测试效果.展开更多
Small cluster and periodic surface models with low coverages of intermediates are frequently employed to investigate reaction mechanisms and identify active sites on nanoparticles(NPs)in density functional theory(DFT)...Small cluster and periodic surface models with low coverages of intermediates are frequently employed to investigate reaction mechanisms and identify active sites on nanoparticles(NPs)in density functional theory(DFT)studies.However,diverse active sites on NPs cannot be sufficiently represented by these simple models,hampering the in-depth insights into the catalytic behavior of NPs.This paper describes the crucial roles of both model and coverage effect on understanding the nature of active sites for CO_(2)reduction over Au and Pd NPs using DFT calculations.Terrace sites exhibit higher selectivity for CO than edge sites on Au NPs,which is opposite to the results on Au periodic surfaces.This contradiction reveals the computational model effect on clarifying active site properties.For Pd catalysts,the coverage effect is more significant.On bare Pd NPs and periodic surfaces,the selectivity for CO at edge sites is nearly identical to that at terrace sites,whereas edge sites display higher selectivity for CO than terrace sites in the case of high CO coverages.Through considering the more realistic models and the coverage effect,we successfully describe the size effect of Au and Pd NPs on CO selectivity.More importantly,this work reminds us of the necessity of reasonable models in DFT calculations.展开更多
To investigate the effects of various erosion control measures on mountain floods, a case study was conducted in Censhui River South Branch Watershed using scenario analysis and soil conservation service （SCS） metho...To investigate the effects of various erosion control measures on mountain floods, a case study was conducted in Censhui River South Branch Watershed using scenario analysis and soil conservation service （SCS） methods. A distributed hydrological model was developed, and watershed parameters were determined based on satellite imagery, digital terrain models, digital maps and field investigations. Two types of erosion control measures were investigated： the variation of vegetation covers and the change of cultivation techniques. Seven scenarios were considered for the test watershed. The results show： （1） while the de-vegetation results in the increase of peak discharge, the improve of vegetation covers decreases peak discharge at watershed scale; （2） by both improving vegetation cover and enhancing terrace-cultivation technology, the peak discharge is reduced and the peak flow arrival time is delayed; （3） attention should be attached to both early warning system and measures changing the underlying surface and conveyance systems.展开更多
文摘针对目前尚未存在有效的中文文本纠错软件测试用例最小化方法的情况,设计了两种中文文本纠错软件测试用例集最小化方法:基于多目标遗传算法的中文文本纠错软件测试用例集最小化方法(Minimization Method based on Multi-objective Genetic Algorithm of Test case for Chinese text error Correction Software,MMG-CCS)和基于TextRank模型的中文文本纠错软件测试用例最小化方法(Minimization Method based on TextRank of Test case for Chinese text error Correction Software,MMT-CCS).MMG-CCS基于问题特点设计了一种中文文本纠错软件测试用例集覆盖度模型,并将测试用例集大小及覆盖度作为目标函数,为了高效求解该问题,MMG-CCS同时对遗传算子进行了改进.此外,MMT-CCS方法能将测试用例集最小化问题映射为图解问题,并根据问题特点对TextRank模型进行了针对性改进.实验结果表明,MMG-CCS和MMT-CCS对测试用例集的缩减程度高,且在不同中文文本纠错软件上对于不同中文文本纠错软件测试用例集均能保持相同的测试效果.
文摘Small cluster and periodic surface models with low coverages of intermediates are frequently employed to investigate reaction mechanisms and identify active sites on nanoparticles(NPs)in density functional theory(DFT)studies.However,diverse active sites on NPs cannot be sufficiently represented by these simple models,hampering the in-depth insights into the catalytic behavior of NPs.This paper describes the crucial roles of both model and coverage effect on understanding the nature of active sites for CO_(2)reduction over Au and Pd NPs using DFT calculations.Terrace sites exhibit higher selectivity for CO than edge sites on Au NPs,which is opposite to the results on Au periodic surfaces.This contradiction reveals the computational model effect on clarifying active site properties.For Pd catalysts,the coverage effect is more significant.On bare Pd NPs and periodic surfaces,the selectivity for CO at edge sites is nearly identical to that at terrace sites,whereas edge sites display higher selectivity for CO than terrace sites in the case of high CO coverages.Through considering the more realistic models and the coverage effect,we successfully describe the size effect of Au and Pd NPs on CO selectivity.More importantly,this work reminds us of the necessity of reasonable models in DFT calculations.
文摘To investigate the effects of various erosion control measures on mountain floods, a case study was conducted in Censhui River South Branch Watershed using scenario analysis and soil conservation service （SCS） methods. A distributed hydrological model was developed, and watershed parameters were determined based on satellite imagery, digital terrain models, digital maps and field investigations. Two types of erosion control measures were investigated： the variation of vegetation covers and the change of cultivation techniques. Seven scenarios were considered for the test watershed. The results show： （1） while the de-vegetation results in the increase of peak discharge, the improve of vegetation covers decreases peak discharge at watershed scale; （2） by both improving vegetation cover and enhancing terrace-cultivation technology, the peak discharge is reduced and the peak flow arrival time is delayed; （3） attention should be attached to both early warning system and measures changing the underlying surface and conveyance systems.
