摘要
气泡最大压力法测定表面张力时,不仅要作γ-c曲线(表面张力对浓度作图),还要用切线法求得曲线上各点的斜率。后者实施难度大,且带有很大的人为主观性,容易导致较大的偶然误差。鉴于当下计算机已普及,可尝试用最小二乘法拟合法出多种不同类型的γ-c解析关系式,然后对c求导。再直接将c代入导数关系式,可快捷、客观、准确地求得不同浓度下的dγ/dc值。
To measure the surface tension with the maximum bubble pressure method, one has to draw theγ-c curve, and determine the slope of many points on the curve by the tangent method. The latter is not only difficult to achieve, but also subjective with large accidental errors. Nowadays computers are popular in use. This reminds me of fitting various types of analytic expressions for the γ-c curve by the least square method. By differentiating γ with respect to c, a differential expression is obtained. By sub- stituting c values into this differential expression, the dγ/dc values then could be obtained conveniently, objectively and accurately. This analytic method is recommended for expanding the ken of students.
出处
《化工高等教育》
2013年第1期63-65,共3页
Higher Education in Chemical Engineering
基金
南京理工大学高等教育教学改革研究课题
关键词
气泡最大压力法
表面张力
曲线拟合
Maximum bubble pressure method
Surface tension
Curve fitting
