利用化学方法，由外消旋环氧氯丙烷出发，合成丁酸环氧丙酯，精制后可获得纯度96%以上的丁酸环氧丙酯，收率为47%。
Glycidyl butyrate was synthesized from racemic epichlorohydrin and butyric acid by chemical means. The purity of the refined product was over 96% and the yield was about 47%.
尽管，许多卫星在36000千米处形成一个类似土星光环的环，但这个高度的卫星都需要花费24小时绕地球一圈。因此，它们一直在地球上空的同一点盘旋。
Many, though, form a ring like Saturn's at a distance of 36,000km, the place at which an object takes 24 hours to orbit the Earth and thus hovers continuously over the same point of the planet.
有着与众不同的中心恒星环，旋臂上还点缀着大量炽热的年轻恒星组成的蓝巨星簇，NGC 1097就成为绝佳的观测目标。
With this distinctive central star-forming ring, and the addition of numerous bluish clusters of hot, young stars dotted through its spiral arms, NGC 1097 makes a stunning visual object.
目前工业中应用最多的是水环式真空泵和旋片式真空泵等。
Application of the current industry is the largest water-ring vacuum pumps and vacuum pumps and other rotating chip.
介绍旋动式人工流产器的工作原理、结构及组成，探讨旋流环的制备方法。
The working principle, the structure and the constitution of the rotation ring for the artificial abortion apparatus are introduced.
阐述了自压密封旋启式止回阀的结构特点、工作原理、材料选用和止推环设计。
Describe the structure characteristic and working principle of pressure seal swing check valve. Material selection and thrust ring design.
干燥室上部加装陶析环及旋流片可以控制出口物料的粒度及湿度，以达到不同物料的终水份粒度的要求。
There are rotation flow pieces and elutriation ring inside the drying charnber . it is used to control the moisture and granule of raw material to the needed level.
采用高速摄影和数字化处理的研究方法，对鞍马“隔两环宽臂支撑托马斯全旋”动作进行生物力学分析。
By the high -speed photography and digital processing , the authors biomechanically analyze the movement of Thomas flank circle with wide arms support between two rings on pommelled horse.
在建立筒形件强旋有限元力学模型过程中，旋轮与工件接触区及其边界的描述是重要的一环。
The contact zone between roller and workpiece and its contour's definition are the cruxes of establishing the FEM mechanical model.
结合动量理论和涡流理论，推导了桨叶环量方程，用广义尾流模型计算了旋翼下洗流场。
Combining momentum theory and vortex theory, rotor circulation equation was deduced. The rotor down-wash flow field was calculated using generalized down-wash flow model.
本文从旋翼的广义经典涡流理论出发，通过环量对诱导速度的贡献的简化处理，推导出旋翼诱导速度的二阶分布。
In this paper, firstly, relations of first two harmonic induced velocities to the lower and same-order harmonic circulations are obtained from the generalized classical vortex theory of the rotor.
这个环会帮助保持腿的内旋。
介绍旋动式人工流产器的工作原理、结构及组成，探讨旋流环的制备方法。
The working principle, the structure and the constitution of the rotation ring for the artificial abortion apparatus are introduced. The preparation method of the rotation ring is discussed.
通过模型旋翼试验得到了合理的直升机涡环边界判据，并由此计算得到了直升机通用涡环状态边界。
A reasonable criterion of vortex ring state boundary for helicopter is acquired based on model rotor tests.
目前工业中应用最多的是水环式真空泵和旋片式真空泵等。
At present, the most widely used in industry is the water ring vacuum pump and rotary vane vacuum pump and so on.
本实用新型是一种旋耕式农田耕作机械的尾轮。它由环型刀片，胶尾轮或其它材料制成的尾轮，尾轮叉组成。
The utility model relates to a back wheel of a spiral plowing farmland tillage tool, which comprises a ring blade, a back wheel made form rubber or other materials, and a back wheel fork.
提供了一种既能保证套管居中，又能产生水泥浆环空螺旋流的套管弹性旋流扶正器。
A kind of device which can keep the casing at the center of borehole and can also generate helical flow of cement slurry, which is the Spring Whirlflow casing Centralizer, is presented in this paper.
本发明的合成方法简便直接，从外消旋的螺环二酮出发得到螺环骨架具有不同绝对构型的光 学纯的手性配体。
The synthetic method is simple and convenient and direct; and the spiral ring skeleton obtained from spiro-diketone has optical pure chiral ligand with different absolute configurations.
本发明公开了一株可降解多环芳烃的海旋菌及其应用。
The invention discloses thalassospira capable of degrading polyaromatic hydrocarbon and application thereof.
当“U”形弯环断裂时，可将轨枕下面螺帽旋下，换上新的“U”形弯 环，即可恢复使用。
When the U-shaped bent loop is broken, the nuts under the sleeper can be screwed off and a new U-shaped bent loop can be assembled for restoring use.
罗茨式真空泵，罗茨螺杆机组，罗茨旋片机组，罗茨水环机组，罗茨滑阀机组，移动式真空机组等。
Roots Vacuum Pumps, Roots and Vane Systems, Roots and Water-ring Systems, Roots and Piston Systems, Moves Freely Vacuum Systems and so on.
近几年我公司开发了“摩天环车”、“冲浪旋艇”、“宇宙旋风”且均已获得了国家专利。
Recently, the newly-produced products such as "Sky Ring Car", "Surfing Motorboat" and "Air Flying"have all obtained the national patents.
本发明是一种旋轮翼，它具有缘肋和桨叶，其特征是：把旋翼或螺旋桨的桨叶和飞轮的轮缘及加强环肋结构有机地结合成为一个整体，使之具有飞轮与旋翼或螺旋桨的双重功能；
The invention is characterized by the combination of the blades of a propeller and the wheel rim or ring rib of a flywheel, and has dual functions of a flywheel and a rotor wing or a propeller;
本发明是一种旋轮翼，它具有缘肋和桨叶，其特征是：把旋翼或螺旋桨的桨叶和飞轮的轮缘及加强环肋结构有机地结合成为一个整体，使之具有飞轮与旋翼或螺旋桨的双重功能；
The invention is characterized by the combination of the blades of a propeller and the wheel rim or ring rib of a flywheel, and has dual functions of a flywheel and a rotor wing or a propeller;
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