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土壤塑液限测定方法 被引量:1
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作者 张格 刘乃庆 吴华 《农业与技术》 1996年第5期44-45,共2页
土壤塑液限测定方法张格,刘乃庆,吴华(吉林工业大学)一、概述土壤是一个非常复杂的体系,是由固体、液体和气体物质构成的。建筑、公路、制陶业以及农业机械等行业都与土壤性能紧密相关,因而,测定土壤物理特性是十分重要的和必要... 土壤塑液限测定方法张格,刘乃庆,吴华(吉林工业大学)一、概述土壤是一个非常复杂的体系,是由固体、液体和气体物质构成的。建筑、公路、制陶业以及农业机械等行业都与土壤性能紧密相关,因而,测定土壤物理特性是十分重要的和必要的。本文着重对土壤塑液限测定进行了... 展开更多
关键词 土壤 塑液限 测定
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Numerical Simulation of Extrusion Pressure in the Process of Hydrostatic Extrusion 被引量:1
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作者 张朝晖 王富耻 +1 位作者 程荆卫 李树奎 《Journal of Beijing Institute of Technology》 EI CAS 2001年第1期63-68,共6页
In order to study the laws of the extrusion pressure changing with the extrusion parameters in the process of hydrostatic extrusion for the tungsten alloys, the large deformation elasto plastic theory and the sof... In order to study the laws of the extrusion pressure changing with the extrusion parameters in the process of hydrostatic extrusion for the tungsten alloys, the large deformation elasto plastic theory and the software of ANSYS 5 5 are used to carry out the numerical simulation research. The laws of the extrusion pressure changing with the extrusion parameters, such as the die angle, extrusion ratio, and friction coefficient, are obtained. The simulation results are in good agreement with the experimental ones, and the simulated results are believable. 展开更多
关键词 hydrostatic extrusion elasto plastic finite element method extrusion pressure numerical simulation
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Soil Atterberg Limits and Consistency Indices as Influenced by Land Use and Slope Position in Western Iran 被引量:2
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作者 Zahra ZOLFAGHARI Mohamamd Reza MOSADDEGHI +1 位作者 Shamsollah AYOUBI Hamid KELISHADI 《Journal of Mountain Science》 SCIE CSCD 2015年第6期1471-1483,共13页
Atterberg limits and consistency indices are used for classifications of cohesive(fine-grained) soils in relation with compaction and tillage practices. They also provide information for interpreting several soil mech... Atterberg limits and consistency indices are used for classifications of cohesive(fine-grained) soils in relation with compaction and tillage practices. They also provide information for interpreting several soil mechanical and physical properties such as shear strength, compressibility, shrinkage and swelling potentials. Although, several studies have been conducted regarding the land use effects on various soil mechanical properties, little is known about the effects of land use and slope positions on Atterberg limits and consistency indices. This study was conducted to investigate the effects of land use and slope position on selected soil physical and chemical properties, Atterberg limits and consistency indices in hilly region of western Iran. Three land uses including dryland farming, irrigated farming and pasture and four slope positions(i.e., shoulder, backslope, footslope, and toeslope) were used for soil samplings. One hundred eleven soil samples were collected from the surface soil(0-10 cm). Selected physical and chemical properties, liquid limit(LL), plastic limit(PL) and shrinkage limit(SL) were measured using the standard methods; and consistency indices including plastic index(PI), friability index(FI), shrinkage index(SI) and soil activity(A=PI/clay) were calculated. The results showed that irrigated farming significantly increased organic matter content(OM) and OM/clay ratio, and decreased bulk density(ρb) and relative bulk density(ρb-rel) as a result of higher biomass production and plant residues added to the soil compared to other land uses. Except for sand content, OM, ρb, cation exchange capacity(CEC) and calcium carbonate equivalent(CCE), slope position significantly affected soil physical and chemical properties. The highest values of silt, OM/clay and CEC/clay were found in the toeslope position, predominantly induced by soil redistribution within the landscape. The use of complexed(COC)- noncomplexed organic carbon(NCOC) concept indicated that majority of the studied soils were located below the saturation line and the OM in the soils was mainly in the COC form. The LL, PI, FI and A showed significant differences among the land uses; the highest values belonged to the irrigated farming due to high biomass production and plant residues returned to the soils. Furthermore, slope position significantly affected the Atterberg limits and consistency indices except for SL. The highest values of LL, PI, SI and A were observed in the toeslope position probably because of higher OM and CEC/clay due to greater amount of expandable phyllosilicate clays. Overall, soils on the toeslope under irrigated farming with high LL and SI and low values of FI need careful tillage management to avoid soil compaction. 展开更多
关键词 Land use Slope position Atterberg limits Soil consistency Relative bulk density Complexed organic carbon
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