natural sampling meaning in English

自然取样

There are five natural sample zones of adiantum reniforme l . var . sinense y . x . lin investigated , and recorded 34 species . 10 dominant species were used to calculate the niche width of populations and the niche overlap interpopulations
调查了5个自然样地，记录了34个伴生种，取10个优势种进行种群生态位宽度与生态位重叠的计算。
The basic physical and mechanical properties , mineral composition , micro structures , swelling potential , consolidated drained triaxial shear strength , parameters of constitutive model and residual strength of the soft clayey rocks were tested in laboratory with a large number of natural samples . the changing trend of the strength about these rocks is obtained by modeling the condition of softening due to immersion . from the principles of modern soil mechanics , the structural and swelling characteristics of soft clayey rocks were analyzed systematically
本文通过现场调查，查明风化泥质软岩的宏观结构特征，利用现代试验测试手段，取原状土系统进行特殊土室内土工试验，测定土的基本物理力学特性、矿物成分及微观结构、膨胀性、三轴排水剪强度及本构模型参数、软化残余强度，并模拟土体在长期浸水软化后的强度变化趋势，测试该类土的浸水软化残余强度。