The scheme of "four sides, double drilling, double grouting and four-eight cross" is adopted and a new technology of chemical pregrouting is introduced in the inclined shaft construction.
赵庄矿水文地质条件复杂,主斜井穿越多个厚砂岩含水层,井简水治理是阻碍掘进的难点,在主斜井施工中采取了“四边,双钻双注,四八交叉”施工方案,引进了化学预注浆新工艺,达到了预期封水效果,实现了快速施工。
A CNC machine for making boxshaped parts with metal sheets using the specific bending process and synchronous electrohydraulic control technique is described.
研究了四边折边机数控系统分布式控制结构及模块化的软件结构，提出了提高系统可靠性的措施。
Based on the description, input, graphic display, process analysis, process simulation, and automatic programming for the bending of a workpiece, the realization by the automatic programming system for a CNC machine for making boxshaped parts with metal sheets to automatically generate and check the process control codes according to process graphs and charts is discussed.
从折弯工件的描述、输入、图形显示、工艺分析、过程仿真、自动编程等方面着手，分析了实现从工艺图纸到过程控制代码的自动生成及校验的数控四边折边机自动编程系
A plane figure with four sides and four angles.
四边形有四个边和四个角的平面图形
A quadrilateral having no parallel sides.
没有平行边的四边形
parallelogram illusion
平行四边形错觉 平行四边形错觉
a parallelogram with four equal sides; an oblique-angled equilateral parallelogram.
四个边相等的平行四边形；不是直角的等边平行四边形。
parallelogram linkage steering
四边联杆式转向机构
double link jib in parallelogram
平行四边形组合臂架
fundamental period parallelogram
原始周期平行四边形
parallel motion linkage
平行四边形悬挂装置
primitive period parallelogram
基本周期平行四边形
primitive parallelogram of period
周期的原始平行四边形
diagonal line of a complete quadrilateral
完全四边形的对角线
digital orthophoto quadrangles (DOQ's)
数字化正射摄影四边形
quadrilateral speed-time curve
四边形速度时间曲线
The town is hedged in by low hills.
这城镇四边有低山环绕。
A quadrilateral having two parallel sides.
梯形一个有两条平行边的四边形
(in US) a quadrilateral with no parallel sides.
（在美国）没有平行边的四边形。
(in US) a quadrilateral with two parallel sides.
（在美国）有两个平行边的四边形。
a polyhedron whose faces are trapeziums.
由不等边四边形面组成的多面体。