A genome-wide association study(GWAS)was conducted on a collection of 166 Chinese rice mini-core germplasms to investigate cold tolerance traits across various rice growth stages.Population structure analysis revealed...A genome-wide association study(GWAS)was conducted on a collection of 166 Chinese rice mini-core germplasms to investigate cold tolerance traits across various rice growth stages.Population structure analysis revealed that these accessions could be categorized into six subgroups,consistent with their geographical origins.展开更多
Dramatic tool temperature variation in end milling can cause excessive tool wear and shorten its life, especially in machining of difficult-to-machine materials. In this study, a new analytical model-based method for ...Dramatic tool temperature variation in end milling can cause excessive tool wear and shorten its life, especially in machining of difficult-to-machine materials. In this study, a new analytical model-based method for the prediction of cutting tool temperature in end milling is presented.The cutting cycle is divided into temperature increase and decrease phases. For the temperature increase phase, a temperature prediction model considering real friction state between the chip and tool is proposed, and the heat flux and tool-chip contact length are then obtained through finite element simulation. In the temperature decrease phase, a temperature decrease model based on the one-dimension plate heat convection is proposed. A single wire thermocouple is employed to measure the tool temperature in the conducted milling experiments. Both of the theoretical and experimental results are obtained with cutting conditions of the cutting speed ranging from 60 m/min to100 m/min, feed per tooth from 0.12 mm/z to 0.20 mm/z, and the radial and axial depth of cut respectively being 4 mm and 0.5 mm. The comparison results show high agreement between the physical cutting experiments and the proposed cutting tool temperature prediction method.展开更多
基金supported by the Key Research and Development Program of Ningxia Hui Autonomous Region,China(Grant No.2023BCF01010)the National Natural Science Foundation of China(Grant No.32201765)+2 种基金the Key Research and Development Program of Shandong Province,China(Grant No.2019-GNC106107)the Science and Technology Innovation Program of Chinese Academy of Agricultural Sciencesthe National Crop Germplasm Resources Center,China(Grant No.NCGRC-2023-02).
文摘A genome-wide association study(GWAS)was conducted on a collection of 166 Chinese rice mini-core germplasms to investigate cold tolerance traits across various rice growth stages.Population structure analysis revealed that these accessions could be categorized into six subgroups,consistent with their geographical origins.
基金supported by the National Basic Research Program of China (No. 2013CB035802)National Natural Science Foundation of China (No. 51475382)
文摘Dramatic tool temperature variation in end milling can cause excessive tool wear and shorten its life, especially in machining of difficult-to-machine materials. In this study, a new analytical model-based method for the prediction of cutting tool temperature in end milling is presented.The cutting cycle is divided into temperature increase and decrease phases. For the temperature increase phase, a temperature prediction model considering real friction state between the chip and tool is proposed, and the heat flux and tool-chip contact length are then obtained through finite element simulation. In the temperature decrease phase, a temperature decrease model based on the one-dimension plate heat convection is proposed. A single wire thermocouple is employed to measure the tool temperature in the conducted milling experiments. Both of the theoretical and experimental results are obtained with cutting conditions of the cutting speed ranging from 60 m/min to100 m/min, feed per tooth from 0.12 mm/z to 0.20 mm/z, and the radial and axial depth of cut respectively being 4 mm and 0.5 mm. The comparison results show high agreement between the physical cutting experiments and the proposed cutting tool temperature prediction method.
