榆树

A dicot family of the order Urticales including: genera Ulmus; Celtis; Planera; Trema.

苜蓿目中的双子叶植物科包括；榆树属；朴属；水榆属；山黄麻属。

It is planting usually as four-sides afforesting and decretive plant investigated its history and present situation was investigated completely.

榆树早春果实形似铜钱、耐修剪、抗逆性强，在&四旁&绿化中常有栽种，也是实际应用价值很高的观赏树种。

The estate was fringed with stately elm s.

那片地以挺拔的榆树为边界。

Populus alba × berolinensis, Salix babylonica and Quercus mongolica mainly emitted isoprene; Pinus tabulaeformis mainly emitted α-pinene; Ulmus pumila, Gleditsia japonica and Syringa oblate mainly emitted limonene; Ligustrum obtusifolium mainly emitted isoprene, limonene and α-pinene at different time. The highest emission rates were observed for Populus alba × berolinensis and Salix babylonica.

不同树种排放的BVOCs组成明显不同，银中杨、垂柳和蒙古栎以排放异戊二烯为主；油松主要释放α－蒎烯；榆树、皂角和丁香以释放柠檬烯为主；水腊在不同时段其BVOCs组成情况变化较大，主要释放异戊二烯、柠檬烯和α－蒎烯；其中银中杨和垂柳的BVOCs释放量明显高于其它树种。

The BVOCs flux from Populus alba × berolinensis, Salix babylonica, Ulmus pumila, Gleditsia japonica, Syringa oblate and Ligustrum obtusifolium in Shenyang were 104.86tC·y-1, 168.66tC·y-1, 3.56tC·y-1, 1.27tC·y-1, 4.07tC·y-1 and 1.33tC·y-1, respectively.

在实测数据基础上，估算出沈阳市6种主要绿化树种银中杨、垂柳、榆树、皂角、丁香和水腊在自然条件下的BVOCs年排放量分别为104.86tC，168.66tC，3.56tC，1.27tC，4.07tC和1.33tC。

Based on isotopic ages and the cycle of magamtism, the ages of Yanbian granites can be subdivided into five periods:①late Permian granites (260-245Ma), the typical plutons are Liukesong and Liangbing plutons, and the main rock type include diorite-monzonitic-K syenogranites;②Triassic granites (225-200Ma), the typical plutons are Sandaogou, Chunyang, Qishiergedingzi, Dahuanggou, Naozhi, and Qinglinzi plutons, the main rock type include quartz dioritesgranodiorites-monzonitic-alkali granites;③early Jurassic granites (190-180Ma), which composed of quartz diorites-granodiorites - monzonitic ,and the typical plutons are Shimen, Miantian, Daxinggou and Yushuchuan rock;④Middle-Late Jurassic (170-150Ma), which composed of granodiorites- monzonitic- garnet-bearing muscovite granites, the typical plutons are Huangniling, Weizigou, Loutuoshan and Dongqing rock;⑤early Cretaceous (about 130Ma), the typical pluton is Zhongping pluton, and its rock type is paulite diorite.

另外，根据同位素年龄和岩石组合并考虑到岩浆的旋回性，将延边显生宙花岗岩进一步划分为五个期次：1。晚二叠世(260-245Ma)，代表性岩体为六棵松和亮兵，主体岩性为辉石闪长岩、二长花岗岩和钾长花岗岩；2。三叠世(225-200Ma)，代表性岩体为三道沟、春阳、七十二个顶子、大荒沟、闹枝、青林子，岩石组合为石英闪长岩—花岗闪长岩—二长花岗岩—碱长花岗岩，以花岗闪长岩和二长花岗岩为主；3。早侏罗世(190-180Ma)，石英闪长岩—花岗闪长岩—二长花岗岩组合，主体岩性为花岗闪长岩，代表性岩体有石门、棉田、大兴沟、榆树川等；4。中侏罗世(170-150Ma)，主体岩性为花岗闪长岩和含石榴石花岗岩，代表性岩体有黄泥岭、苇子沟、骆驼山、东清5。

However, relating to investigate the modes, courses and characteristics of the orogenetic process in Paleozoic and after orogenetic process, the cognitive divergence have still occurred.

通过对新疆北东部地区不同构造区带构造作用的方式、过程和特点的研究，确定：①南天山榆树沟高压麻粒岩地体的正变质原岩是一个基本完整的蛇绿岩套，其经历了俯冲至下地壳的高压麻粒岩相、构造抬升至深地壳麻粒岩相以及快速构造折返至角闪岩相的变质过程，代表了南天山洋壳俯冲、变质、随后折返的过程，并首次确定了变质过程的PTt轨迹；②奥陶纪末期中天山北缘发生洋盆俯冲、地体增生作用，此时萨日达拉地区处于岛弧活动带；中石炭世晚期中天山小型洋盆关闭，准噶尔地块与伊犁—中天山板块斜向对接随后发生脆韧性质近水平高温低速右行走滑剪切；③根据巴音沟地区不构成蛇绿岩套有效成分的硅质岩具有与活动大陆边缘密切相关的地球化学特征以及洋中脊玄武岩显示其岩浆源区受到消减带流体交代作用的影响，结合区域地质资料，首次提出巴音沟蛇绿岩带所代表的洋盆古构造环境为弧后盆地，并于早石炭世至中石炭世末期间，经历了扩张、收缩和闭合过程；④首次在克拉麦里蛇绿混杂岩带中分解出具有N-MORB、T-MORB与OIB三种不同类型的火山岩岩石组合，反映了洋盆俯冲

In order to better understand the determinants of tree height limit,32 tall tree species such as Parashorea chinensis,Sapium baccatum,Garcinia cowa,Eucalyptus citriodora,E.grandis×E.urophylla,Albizia falcataria,Populus tomentosa,Platanus hispanica,Ginkgo biloba,Pinus tabulaeformis,Ulmus pumia,Salix gordeivii,and Elaeagnus angustifolia from typical environments such as Xishuangbanna rainforest,Guangzhou subtropical area,Zhengzhou,Beijing,Helanshan mountain and Maowusu sandland in China were studied.

为了更好地了解树高极限的限制因素，本文对全国典型水分分布区域西双版纳、广州、郑州、北京、贺兰山和毛乌素沙地等地区生长的望天树、浆果乌桕、小叶藤黄、柠檬桉、巨尾桉、南洋楹、毛白杨、悬铃木、银杏、油松、榆树、沙枣、小黄柳等32种较高的木本植物进行了研究。

It is positive to improving and increasing beautify Harbin landscape. It supply directive advices to manufacture of the Ulmus pwnila to avoid the blindness of manufacture and application.

正确对待和重视乡土树种在园林中的作用，对于提高哈尔滨市的绿化质量和绿化效益有着非常积极的意义；同时也可为榆树的生产提出指导性意见，避免生产和应用的盲目性。

Temperate Ulmus pumila sparse forest grassland ecosystem in Inner Mongolia Plateau is a special ecosystem in China, and even in the world. Its study is of significance in deeply understanding the vegetation distribution patterns in the earth, and favoring the protection of this ecosystem.

内蒙古高原分布的温带榆树稀树草原生态系统在中国乃至世界上都是一种特殊的生态系统，对于它的研究可加深对植被分布规律的理解，且有利于该系统的保护。

According to the clear water experiment, aeration performance of the new equipment is good with high total oxygen transfer coefficient and oxygen utilization ratio.

曝气设备的动力效率在叶轮转速为120rpm～150rpm时取得最大值，此时氧利用率和充氧能力也具有较高值。

The environmental stability of that world - including its crushing pressures and icy darkness - means that some of its most famous inhabitants have survived for eons as evolutionary throwbacks, their bodies undergoing little change.

稳定的海底环境─包括能把人压扁的压力和冰冷的黑暗─意谓海底某些最知名的栖居生物已以演化返祖的样态活了万世，形体几无变化。