The acceleration of an object is directly proportional to the net force acting on it and inversely proportional to its mass 物体的加速度与所受的合外力成正比，与物体的质量成反比。
The data show that maximum oil saturation of sandstones is directly proportional to their porosity 对这些数据的统计分析表明，不同润湿性砂岩孔隙度与最大含油饱和度大致存在线性定量关系。
The relationship between two quantities when a change in a second quantity is directly proportional to a change in the first quantity 两个变量之间的一种关系,第二个量的变化直接和第一个量的变化成比例。
The economic development is directly proportional to the expansion of business activities , and this will result in increase of business disputes 经济的发展与商事活动规模的扩大成正比，商事纠纷发生的数量必然增加。
The benefit of internet empowerment is directly proportional to the size of the market . a large market represents a sizable potential customer base and makes investment more worthwhile 互联网提升资讯能力的效益与市场规模成正比，庞大市场代表广阔的顾客基础，令投资更物有所值。
The main disadvantage of iterative algorithm is its slow speed and the time cost of image reconstruction is directly proportional to the number of projections and the size of reconstruction image 迭代重建法最大的缺点是速度慢，其花费时间同投影数的多少以及重建图像的大小成正比。
One disadvantage of asymmetric keys is that they take much longer to encrypt a message than do symmetric keys , and the encryption time is directly proportional to the size of the message 非对称密钥的一个缺点是加密消息要比对称密钥花费更长的时间，而且加密时间直接与消息的长短成正比。
The main reason is that software models can often be terribly inaccurate in unpredictable ways : clearly , the practical value of any model is directly proportional to its accuracy 主要原因是软件模式经常会导致不可预知的严重性错误：我们都清楚，任何一个模式的实际价值与它的正确性直接成比例。
Referring first to the equation of the shunt motor shows that the downwards slop of the speed / torque curve is directly proportional to the armature resistance with constant flux and voltage 并励电动机（机械特性）方程表明：若磁通和电压恒定，则向下倾斜的转矩/速度曲线的斜率是直接与电枢电阻成正比的。
（ the force between two point charges at rest is directly proportional to the product of the charges and inversely proportional to the square of the distance between them 在真空中，两个静止的点电荷之间的相互作用力的大小与两电荷所带电量的乘积成正比，与它们之间距离的平方成反比，作用力的方向沿两电荷的连线。
