actinic focus
【物理】光化学线焦点
concentrate rays of light into a focus
把光线集中在焦点上
"A convex lens causes rays to converge on a single point, the focal point."
会聚透镜使光线会聚于一点,即焦点。
The midpoint Between the foci is the center. One property of an ellipse is that the reflection off its Boundary of a line from one focus will pass through the other.
焦点之间的中点为中心。椭圆的一个特性是:连自一个焦点的直线边界反折会通过另一个焦点。
Analysis and Measurement of Spot Focusing Lens Antenna Resolution
点聚焦透镜天线分辨率的分析与测量
② when , the horizontal projection curve of the intersection curve is the Cassini oval family which is confocal.
②当时，为共焦点的卡西尼卵形线族；
The Research on the Generalized Elliptic Curve with Three Foci;
“三焦点”广义椭圆曲线及其传动特性
Research on the X-ray Imaging Based on Micor-Focus
微焦点X射线源成像质量分析与研究
The Research on the Generalized Elliptic Curve with Three Foci
“三焦点”广义椭圆曲线及其传导特性
Notice that in all cases, the rays either perge from or converge toward the foci.
注意在所有的情况下，光线不是从焦点发散就是会聚到焦点。
A fixed point whose relationship with a directrix determines a conic section.
焦点一个与准线的关系决定圆锥形状的定点
Decision Theorems for the Center and Focus of a Class of Nonlinear Differential Equati ons
一类非线性微分方程组的中心和焦点判定定理
Design of a Control System of Compensation for the Focal Displacement of Feed of a 50m Antenna
50米天线馈源焦点偏移补偿控制系统的设计
Research on Meridian Lines Design for Progressive Addition Lenses
渐进多焦点眼用镜片的子午线设计研究
Of or relating to a focus.
焦点的焦点的或与焦点有关的
A Survey of Studies on Focus;
焦点、焦点结构及焦点的性质研究综述
Evaluation of Online Knowledge Communication Based on Focus Group
基于焦点团体的在线知识交流评价——以在线参考咨询工具Wiki为例
Focus-to-film distance(f.f.d)
焦点-胶片距离(焦距)