三个组成的

By studying the internal structure and working principle of 555 timer, this paper introduces three typical circuits----Schmitt trigger, Bistable multivibrator and Astable multivibrator----which are composed by 555 timer. Furthermore, it explores the various applications of 555 timer in circuit designing through the expansion of the circuits and eventually same experience and methods offers in circuit designing by using 555 timer.

本文通过研究555定时器的内部结构和工作原理，介绍了其组成的施密特触发器，单稳态触发器和多谐振荡器等三个典型电路，并通过这些电路的扩展，探讨了555定时器在电路设计中的各种应用，由此得出用555定时器设计电路的经验和方法。

Sediment from river is not the main source of the Rushan Bay now any more ,which leads to the change of balance of sedimentation power. Sediment will transport because of the drive of hydrodynamic elements in macroscopic view .Direction of suspended load is basicly the same as tidal current .Flood tide makes suspended load transport to tip of the inner Bay and to the Mouth in exterior Bay .The direction of longside sediment transport in two sides of the Mouth mainly focus in the Mouth .Because the coastline along the exterior Bay is very meandering and it belongs to the type of bedrock ,besides some sediment going into the inner Bay ,so actual net sediment discharge rate is less than calculation .It develops an ebb delta out of the Mouth and forms tidal sand ridge ,tidal washing canal ,barrier bar and marine physiognomy ;The result of model simulation disclosures that differences of sediment erosion and siltation between single tidal action and wave-current action are very big .From the analysis of sediment composition、sediment sources and stability of beach and ridge ,this article gets the conclusion that the channel has the possibility to silt ,though the course maybe very slow.

通过分析研究文章得出如下结论：沉积物平面分布与水动力的时空变化存在很好的相关性；口门外发育落潮流三角洲，形成潮流沙脊、潮流冲刷槽、浅滩、拦门沙等水下动力地貌；乳山湾河流来沙已不是湾内泥沙主要来源导致沉积水动力平衡发生改变，宏观上表现在泥沙受水动力驱动发生不断运移；悬沙运移方向与涨潮流方向基本一致，湾内涨潮流带来的悬移质泥沙向湾顶运移，湾外悬移质泥沙主要向口门方向运移；湾口两侧岸段沿岸输沙方向均指向口门方向，由于乳山湾外海岸线曲折，两侧岸段以基岩为主，加之部分泥沙进入湾内，实际净输沙量小于计算值；数值模拟发现潮流单独作用与波流共同作用下泥沙蚀淤模拟差别较大；从沉积物组成、泥沙来源及滩槽稳定性三个方面分析，文章认为研究区存在航道淤积的可能性，但过程相对较慢。

Firstly, the fly ash is separated into three parts according to its mineralogical composition, they are ferruginous spheres, mullite-corundum and glass phases. Secondly, the contents of these elements of the original fly ash, the ferruginous spheres and the mullite-corundum are determined by chemical analysis and ICP-MS, respectively, and thus the element contents in the glass phase can be obtained by calculation.

首先根据高铝粉煤灰的物相组成特点采用新的分离方法将之分离为三个相：铁质微珠、莫来石－刚玉相以及玻璃相；然后分别用化学分析和ICP-MS测试主微量元素在高铝粉煤灰、铁质微珠以及莫来石－刚玉相中的含量，并结合相关数据计算出这些元素在玻璃相中的含量。

Pukapuka - also known as Danger Island - is the most isolated atoll in the Cooks group, and comprises three islets and a sandbank 1150km northwest of Rarotonga.

Pukapuka是一个危险的岛屿，也是Cooks群岛中最为隔离的一个岛屿。他是由三个小岛和离拉罗汤加岛西北1150千米的一个沙洲组成。

Pukapuka - also known as Danger Island - is the most isolated atoll in the Cooks group, and comprises three islets and a sandbank 1150km northwest of Rarotonga.

Pukapuka，众所周知的危险岛，是Cooks 群岛中最孤立的珊瑚岛，由三个小岛和和一个沙丘拉组成，距拉罗汤加岛西北1150公里。

Pukapuka - also known as Danger Island - is the most isolated atoll in the Cooks group, and comprises three islets and a sandbank 1150km northwest of Rarotonga.

Pukapuka，众所周知的危险岛，是库克群岛中最孤立的珊瑚岛，由三个小岛和一个沙丘组成，距拉罗汤加岛西北1150公里。

Pukapuka - also known as Danger Island - is the most isolated atoll in the Cooks group, and comprises three islets and a sandbank 1150km northwest of Rarotonga.

Pukapuka，也就是众所周知的危险岛，是Cook群岛中最孤立的珊瑚岛，由三个小岛和一个离Rarotonga西北1150公里的沙滩组成。

Pukapuka - also known as Danger Island - is the most isolated atoll in the Cooks group, and comprises three islets and a sandbank 1150km northwest of Rarotonga.

众所周知，Pukapuka是一个危险岛——是库克群岛中最孤立的一个环礁，有三个小岛和位于南太平洋西北方的长1150KM的沙丘组成。

Pukapuka - also known as Danger Island - is the most isolated atoll in the Cooks group, and comprises three islets and a sandbank 1150km northwest of Rarotonga.

Pukapuka是知名的危险岛屿，是库克群岛中最孤立的珊瑚岛，它由三个小岛组成，拉罗汤加岛在其西北1150公里处。

McCormick Place is comprised of three state-of-the-art buildings: the North and South Buildings and Lakeside Center.

麦考密克会展中心是由三个极具艺术特色的建筑组成的：北部和南部的大楼及湖畔中心。

It has been put forward that there exists single Ball point and double Ball points on the symmetrical connecting-rod curves of equilateral mechanisms.

从鲍尔点的形成原理出发，分析对称连杆曲线上鲍尔点的产生条件，提出等边机构的对称连杆曲线上有单鲍尔点和双鲍尔点。

The factory affiliated to the Group primarily manufactures multiple-purpose pincers, baking kits, knives, scissors, kitchenware, gardening tools and beauty care kits as well as other hardware tools, the annual production value of which reaches US$ 30 million dollars.

集团所属工厂主要生产多用钳、烤具、刀具、剪刀、厨具、花园工具、美容套等五金产品，年生产总值3000万美元，产品价廉物美、选料上乘、质量保证，深受国内外客户的青睐