Second, China`s land available for development to many, such as Beijing, Lin said that the time had come to Beijing, only the Third Ring Road, Fourth Ring Road was not yet out, and then there Sihuan, there are five rings, and now has six ring part of the opening, and the tricyclic tetracyclic ring for each additional one is quite a city the size doubled.
第二，中国的土地可用于发展了许多，如北京，林说，现在已经到了北京，只有三环路，四环路还没有了，然后有四环，有五个环，现在有6个环的一部分，开放和三环四环环，每增加一个城市是一个相当的规模增加了一倍。
Finally, the construction of a tetracyclic core of the target molecule was achieved by oxidation of the furan ring and intramolecular Michael addition. The total synthesis of 8-demethyl-pallavicinin B will be completed after two or three more operations starting from a pivotal precursor.
在构建目标分子骨架结构的研究中，成功的运用过酸氧化呋喃环-分子内Michael加成策略构建了四环体系，再经过两到三步的转化即将可以完成8-去甲基-pallavicinin B的全合成。
The three-ring line in Beijing seems to be a small community of small nodes in major cities, small cities, so that it has been the rapid expansion forgotten, whether it is a natural social environment for the community or the community of life are floating population the surrounding high-rise buildings, bustling city noise out of tune, I lived just a few days, so I can not judge how he formed, but her presence is the first time I came to Beijing to surprise some people, the tension of Beijing has been expanding beyond the three-ring style, and even farther into the tetracyclic rings greater geographical direction, but this community did not catch up with this tide, he just quietly watching the dramatic changes around, and silence in their own small world.
这个位于北京三环线上的小社区似乎是一个大城市中的小节点，小的让它在城市的急速扩张中被人遗忘，无论是社区的自然社会环境还是社区中生活的外来流动人口都与周围的高楼大厦、喧嚣的城市繁华格格不入，我才刚刚生活了几天的时间，所以我无法判断他如何形成，但她的存在还是让我这个第一次来北京的人有些吃惊，北京城的张力已经膨胀式的越过了三环，冲向四环五环乃至更远更大的地理方向，但是这样的社区却没有赶上这样的潮头，他只是默默的关注着周围发生的剧烈变化，而沉默于自己小世界里。
The postulated cyclization/rearrangement reaction encompasses oxirane ring protonation and cleavage, cationic/π interaction-directed consecutive tetracyclic ring cyclization, 1, 2-shifted hydride and methyl groups rearrangement, and final highly specific deprotonation step.
这个复杂的环化/重组反应机制包括一开始氧化鲨烯的环氧基被质子化而断裂，接著由碳阳离子-π电子作用(cationic-π interaction)所引导的四个环的环化反应和一连串氢化基及甲基的重排，以及最后具有高度专一性的去质子化步骤。
For example, the shape of the crater there is a round crater with the crater side of the points, the number of terms on the ring are bicyclic flame, tricyclic, tetracyclic of points, the control knob position on the switch there is a variety of grades, and so on.
正确安装燃烧器的方法是，将燃烧器的两个进风口同时对准两个喷嘴，抵住调风板后轻轻向里推进约10毫米后，使燃烧器下定位钉座入枕杠的定位孔。
In accordance with the original thinking, the Second Ring expensive than tricyclic, tricyclic tetracyclic than expensive, but several major features in this area under the influence to subvert the original value has been fully assessed standards.
按照原来的思维，二环比三环，三环四环比昂贵，但几个主要的功能在这方面的影响下，颠覆了原来的价值已经被充分评估标准。