环

As the secondary generation host, CD have received considerable attention because of its particular characterization, and the studies on host-guest interaction based on CD had been transferred from the processes and mechanism of inclusion complex between a pair of host and guest to construction of functional supramolecular aggregates, then these will be useful in the design and preparation of molecular machine and molecular devices, such as molecular pinchers, molecular gears, molecular motors and molecular balances, etc.

它的发展也先后经历了冠醚、环糊精、杯芳烃三代主要的主体化合物，环糊精作为超分子化学的第二代主体化合物以其独特的性质而倍受关注，基于环糊精的主-客体相互作用也在研究单一主体与客体包结形成过程及形成机理的基础上，进而追求具有特定功能的超分子聚集体，为设计制备分子钳、分子齿轮、分子马达、分子秤等重要分子器件和分子机器奠定基础。

Starting from piperonal, the initial total synthesis of CET involved BischlerNapieralski reaction, 3, 2-sigmatropic rearrangement, unusual Nazarov-type electrocyclization, and autoxidative dehydrogenation of desmethylcephalotaxine to desmethylcephalotaxinone etc.

第一条路线我们以胡椒醛为起始原料，经Bischler-Napieralski反应，[3，2]-σ重排，6-6环系到7-5环系的还原重排，Nazarov氧化环化；碱性条件下脱甲基三尖杉碱到脱甲基三尖杉酮碱的氧化脱氢等20步反应，完成了三尖杉碱的全合成。

The piston rings carried in the ring groove are of two basic types: compression rings and oil-control ring.

对活塞环进行的环槽有两种基本类型：压缩环和石油的控制环。

In this paper, we use FEM software ANSYS to simulate. Using FEM to evaluate the strength of pressure hull, the FEM model of outer covering and stiffeners can use shell element to establish, but it may waste much computing time to calculate. Therefore, in this paper, we can evaluate more easier by making use of the idea of effective-width, and considering the stiffener/plating combined moment of inertia.

本文采用有限元素分析软体ANSYS进行求解，在有限元素分析的模拟上，外壳与环肋均可用壳元素建立一实体模型来分析，但是在模型的建立上过於复杂，在解析上也需要更多的时间来计算，因此本文采用有效幅度的观念，考虑环肋与壳板间之组合惯性矩，将环肋部分取梁元素来模拟，如此一来可简化建立模型的困难度，且大大的缩短分析的时间。

The primary step in the thermal decomposition of DNOAF is the disconnection of C-N bond between the furazan rings, followed by the step for the opening of the furazan rings.

在实验基础上提出了DNOAF的热分解历程，DNOAF的热分解首先发生在呋咱环间的C-N键，然后是呋咱环的开环分解。

The port which connects the outgoing primary ring and the incoming secondary ring of the FDDI dual ring.

连接FDDI双环中的出局主环和入局辅环。

Refers to the port in an FDDI topology which connects the incoming primary ring and the outgoing secondary ring of the FDDI dual ring. This port is part of the dual attachment station or a dual attachment concentrator.

指FDDI拓扑中的端口，连接FDDI双环结构中的输入主环和输出辅环。A端口是双连接站点或者双附加配置集中器的一部分。

Next in section 2.3,usingthe finite isolated regular representations in SO(3)character varity of 〓,weobtained a computation formula of SO(3)Donaldson invariants with degree 1 of4—manifold 〓(Theorem 2.3.1).Finally in section 2.4 wediscussed the Donaldson invariants of 4—manifolds with smoothly embedded 2—torus 〓 whose selfintersection is +1,with the help of the single irreducibleSU(2)representation of the principal 〓—bundle over a 2—torus with Eulernumber—1,we got a gluing formula of the Donaldson invariant on the 2—homology represented by 2—torus 〓(Theorem 2.4.1),it is a supplement of P.

最后在§2.4我们讨论了具有自交数为+1的嵌入环面〓的4—流形的Donladson不变量，运用环面上欧拉数为-1的圆丛的单个不可约SU（2）表示给出了Donaldson不变量在环面表示的同调类上的一个粘合公式（定理2.4.1），这一结果补充了P。

The inner toruses represent the nodes at the upper level and the outer toruses represent the nodes at the lower level, which overcomes to some extent the difficulty that the hierarchy expand in the longitudinal direction is not proportionable to that in the latitudinal direction.

CTT通过将层次结构的节点映射到一组同心圆环上，内层圆环表示上层节点，外层圆环表示下层节点，在一定程度上克服了层次结构在横向和纵向扩展的不成比例，并且节点之间的父子关系和兄弟关系都实现了有效的可视化。

The results showed that the amorphous iron oxide has highly catalytic activity. The intermediate products are pyrocatechin, hydroquinone, benzoquinone and low-grade fatty acid. The mechanism of catalyst oxidation is assumed that the free radical OH attacks benzene cycle at the adjacent position and para-position of OH on phenol so that the benzene cycle is opened and low-grade fatty acid is produced and transformed into CO2 and H2O.

结果表明，非晶铁氧化物催化剂在催化氧化降解苯酚时具有较高的催化活性，苯酚降解的中间产物有：对苯二酚、邻苯二酚、苯醌和低级脂肪酸，其降解机理是羟基自由基攻击苯环上OH的部位或对位而使苯环开环，生成低级脂肪酸，并最终转化成二氧化碳和水，从而使苯酚得以降解。

Do you know, i need you to come back

你知道吗，我需要你回来

Yang yinshu、Wang xiangsheng、Li decang,The first discovery of haemaphysalis conicinna.

1〕 杨银书，王祥生，李德昌。安徽省首次发现嗜群血蜱。