同轴的

The results showed that there existed variation among eucalypt families in wood physical-mechanical properties and wood chemistry. There were significant differences among E.pellita families、E.grandis families and E.urophylla譋.grandis clones in wood colors as well as between Strains and within trees.The variation of the surface wetability of wood between E.grandis families and E.urophylla譋.grandis clones were significant.Even in the same families level or clones level,there still existed the same regulation. The degree of collapse of eucalypt had a large relation in the amount of tylosis in vessel and vestured pits on the cell wall of vessel. The more rich tylosis and vestured pits in vessels,the more probability to occur collapse for eucalypt.The biggest moment collapse was probably the critical point of the drying degrade.During the fomulation of drying technology,it is necessary to adopt moderate condition to make the vessels which had formed the biggest moment collapse at the biggest moment collapse resume,especially to prevent the permanent set.At the normal temperature level,the main factors which influenced residual collapse were the contents of ray parenchyma and axial parenchyma .Nearly all the cells joined the course of forming the moment collapse and biggest moment collapse.Interval drying was fit for eucalypt plantation which was easier to make collapse.

研究表明：桉树不同家系间木材物理力学性质和化学组成存在差异；粗皮桉家系间、巨桉家系间、尾巨桉无性系间材色存在显著差异，株间、株内木材材色存在变异；桉树木材表面润湿性在巨桉家系间、尾巨桉无性系间存在着显著差异，在同一家系或同一无性系中，株间和株内也存在着相同的变化规律；桉材皱缩程度与其导管中侵填体的多少和导管壁上纹孔具有的附物多少密切相关，侵填体含物越丰富，纹孔附物越多，桉材越容易皱缩；最大瞬间皱缩是能产生更大干燥降等的临界点，在制定干燥工艺时，必须在最大瞬间皱缩发生时，采用温和条件，使已产生最大瞬间皱缩的细胞尽可能多的恢复，尤其不能使其产生永久变定；在常温条件下，影响残余皱缩的主要因子是射线薄壁细胞和轴向薄壁细胞含量；而对于瞬间皱缩和最大瞬间皱缩，几乎所有细胞都参与它们的形成过程；对于易皱缩的桉树木材，间歇干燥是最有前途的干燥方法。

The calculation results shows that ,(1) when the rotor rotates at the working speed, a local regurgitant whirlpool that is rightabout to the rotor"s rotating direction appears in the classifying region, which makes the separated granules come back to the outside of the classification district and influences the classification efficiency of the turbine classifier;(2) in the condition of a low rotating speed of turbo rotor, ultrafine particles can follow the gas phase by and large, but when the rotating speed increases, a phenomenon of velocity slippage between two phases appears evidently;(3) A operating parameter, air flow rate is so important that can directly influence the stability of flow field in classifying chamber, the bigger the air flowrate is , the steadier the flow field is;(4) Compared with straight blades, the new shape of blades with backward crooked elbow are helpful to improve the stability of flow field and form whole stream easily, also beneficial to advance the classification accuracy and classification efficiency;(5) The motion trace of particles are very complicated when the turbo rotor rotates at a high speed, the constant bounce of the particles appear between the blades and the coarse particles are even bounce back from the inlet, only the finer can pass through the classification area from the oulet;(6) Along with the increase of the rotor"s rotating speed, radiah axial and tangential velocity all begain to fluctuate repetitively like sine-wave, the smaller the particles are, the more violently they fluctuates.

数值模拟结果表明，(1)在涡轮达到工作转速时，在分级区域形成了一个与涡轮旋转方向相反的局部回流涡，它使得分离出来的细粒重又被带回分级轮外边缘，从而严重影响分级机的分级效率；(2)粉尘粒子在涡轮低速运动情况下，基本上能跟随气体运动，但随着转速加大，两相之间出现了明显的速度滑移现象；(3)分级机工作时的风量也是一个比较重要的操作参数，它可以直接影响到分级机内腔流场的稳定性，风量越大，流场越稳定；(4)同直叶片形状相比较，带后弯导板的叶片，有利于改善流场的稳定性，流场容易形成整体流，对提高分级效率和分级精度都非常有利；(5)粒子轨迹线在涡轮转速较高时十分复杂，有的出现了反复的弹跳现象，大颗粒不能通过分级区域而从进口返流了，只有细小的颗粒才从出口处流出；(6)涡轮转速加大时，粒子的径向、轴向和切向速率出现了明显的类似于正弦波的脉动现象，颗粒越小，脉动程度越为剧烈。

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。