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根据坐标测量数据估算建筑物的弯曲程度
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作者 吴斌 吴彬 《南通职业大学学报》 2014年第4期72-75,共4页
建筑物的中心轴线构成空间曲线,要依据曲线上有限个观测点的坐标,计算曲线的弯曲度,用以估算建筑物的弯曲程度。文章建立起空间曲线的三种弯曲度指标。给出了能直接利用原始数据计算平均弯曲度的公式;设计出以极大化搜索为基础的求投影... 建筑物的中心轴线构成空间曲线,要依据曲线上有限个观测点的坐标,计算曲线的弯曲度,用以估算建筑物的弯曲程度。文章建立起空间曲线的三种弯曲度指标。给出了能直接利用原始数据计算平均弯曲度的公式;设计出以极大化搜索为基础的求投影弯曲度的方法;构建了以最佳圆弧拟合为特征的估算整体弯曲度的方案。最后,对三种弯曲度的特点和走势进行了分析比较。 展开更多
关键词 建筑物的弯曲 观测点坐标 平均弯曲度 投影弯曲 整体弯曲
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Effect of sintering atmosphere on composition and properties of NiFe_2O_4 ceramic 被引量:1
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作者 田忠良 张腾 +2 位作者 刘恺 赖延清 李劼 《Journal of Central South University》 SCIE EI CAS CSCD 2015年第2期450-454,共5页
Ni Fe2O4 ceramics were prepared in different sintering atmospheres. The phase compositions, microstructures and mechanical properties were studied. The results show that the stoichiometric compound Ni Fe2O4 cannot be ... Ni Fe2O4 ceramics were prepared in different sintering atmospheres. The phase compositions, microstructures and mechanical properties were studied. The results show that the stoichiometric compound Ni Fe2O4 cannot be obtained in vacuum or atmospheres with oxygen contents of 2×10-5, 2×10-4 and 2×10-3, respectively. All the samples sintered in above-mentioned atmospheres contain phases of Ni Fe2O4 and Ni O. With increasing oxygen content, Ni Fe2O4 content in the ceramic increases, while Ni O content appears a contrary trend. In vacuum, Ni Fe2O4 ceramic has average grain size of 3.94 μm, and bending strength of85.12 MPa. The changes of the phase composition and mechanical properties of Ni Fe2O4 based cermets are mainly caused by the alteration of their properties of Ni Fe2O4 ceramic. 展开更多
关键词 NiFe2O4 ceramic MICROSTRUCTURE mechanical property sintering atmosphere
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