Numerical simulation of pinnate horizontal multilateral well for coalbed gas recovery 煤层气羽状水平井开采数值模拟研究
2.
North american perennial with hairy basal pinnate leaves and purple flowers and plume - tipped fruits 北美洲的一种多年生植物，具有多毛的羽状基叶，紫色的花朵，果实顶端有宿存的羽毛状花柱。
3.
West indian locust tree having pinnate leaves and panicles of large white or purplish flowers ; yields very hard tough wood 西印度群岛的一种角豆树，有羽状的叶片和开白色或紫色大花的圆锥花序， ；木材十分强韧。
4.
Leaves 1 - 2 - ternate or pinnate , ovate - triangular or triangular - ovate , 6 - 10 cm long , 2 . 5 - 4 cm wide , margin irregular coarsely toothed ; petioles c . 10 cm long , sheathed 叶1至2回三出式分裂或羽状深裂，卵状三角形或三角状卵形，长6 - 10厘米，宽2 . 5 - 4厘米，边缘具不规则粗锯齿；叶柄长约10厘米，具鞘。
5.
It is determined by the characteristics of chinese coal seams that they are difficult to exploit ; this paper analyzes three main stimulation technologies : hydraulic fracturing , displacement of multi - gas and oriented pinnate horizontal well - drilling , which can provide technical guidance for developing coal - bed gas more efficiently and reasonably 此外还分析了目前国内外煤层气增产的3项主要技术：水力压裂改造技术、煤中多元气体驱替技术和定向羽状水平钻井技术。
6.
Leaves tufted ; stipes 15 - 30 cm long , densely scaly at base , glabrous above ; sterile lamina about 60 cm long and 20 cm wide , simply pinnate ; pinnae numerous , alternate or subopposite , linear - lanceolate , the largest about 12 cm long and 1 cm wide , base cordate , apex acuminate , margin finely toothed ; veins close , forking once or twice and forming areoles near the midrib ; fertile lamina similar to sterile ones , but somewhat reduced , about 8 cm long and 0 . 4 cm wide , lower surface almost entirely covered with sporangia 叶簇生；叶柄长15 - 30厘米，基部密被鳞片，向上近光滑；不育叶片长约60厘米，宽20厘米，一回羽状；羽片多数，互生或近对生，线状披针形，最长者长达12厘米，宽约1厘米，顶端长渐尖，基部心形，边缘有细密锯齿；叶脉1 - 2次分叉，近中脉形成网眼；能育叶与不育叶相似，但较小，长约8厘米，宽约0 . 4厘米，下部满布孢子囊。
