螺旋一环

All the compounds are characterized by IR and elemental analysis.we design and prepare a bipyridinium supramolecular compound and six coordination compounds, which are also characterized by IR, elemental analysis and X-ray structure analysis. According to X-ray structure analysis, hydrogen bonds and n-n stocking interactions participate in the architecture of three-dimensional framework [H2L1 (NO3)2 (H2O)2]n; one-dimensional zigzag coordination polymer [Hgl21.5CH3OH]n; binuclear metallamacrocycle (HgI2L2)2 3H2O; helical double-stranded one-dimensional coordination polymer [Co2(L2)2-2CH3OH]n; double-stranded one-dimensional coordination polymer [Co2(L3)2-CH3OH-CH3CN]n; and three-dimensional compound [Cu(C5H4NCOO)2(H2O)2]-H2O with hydrogen bonds, three-dimensional coordination polymer {[Cd(C5H6NCOO)2H2O]-DMF}n, which are indirectly obtained from the precursor ligand L3 through metal ion induced the hydrolysis of diamide and self-assembled with the hydrolyzate.

我们首次合成了一个双吡啶鎓超分子化合物和六个过渡金属配合物，并通过IR谱，元素分析和X-ray晶体衍射分析对它们进行了表征。X-ray晶体结构分析表明：超分子化合物[H_2L1·(NO_3)_2·(H_2O)_2]_n是由多种氢键和芳香环间的π-π堆积作用构建的三维无限结构；[HgI_2(L1)·1.5CH_3OH]_n是一维锯齿状配位聚合物；(HgI_2L2)_2·3H_2O是双核金属大环化合物；[Co_2(L2)_2·2CH_3OH]_n是具有一维双螺旋结构的配位聚合物；[Co_2(L3)_2·CH_3OH·CH_3CN]_n为一维双链结构的配位聚合物；以及由非直线形配体L3在金属离子Cu和Cd的诱导作用下发生水解，并且金属离子与水解产物——异烟酸根离子自组装，形成了三维氢键超分子化合物[Cu(C_5H_4NCOO)_2(H_2O)_2]·H_2O和三维配位聚合物{[Cd(C_5H_6NCOO)_2H_2O]·DMF}_n。

As a result,the tooth profile equations, helix angle equations,limit curve equations and induced normal curvature equations for worm and internal gear are obtained.

介绍了一种新型的传动机构超环面行星蜗杆传动，运用啮合理论的包络法建立了这种传动中行星轮与蜗杆、行星轮与内齿轮啮合的基本方程，进而得到了蜗杆和内齿轮的齿面方程、螺旋升角方程、界限曲线方程及诱导法曲率方程等。

With circumspection, as invariably when entering an abode: with solicitude, the snakespiral springs of the mattress being old, the brass quoits and pendent viper radii loose and tremulous under stress and strain: prudently, as entering a lair or ambush of lust or adders: lightly, the less to disturb: reverently, the bed of conception and of birth, of consummation of marriage and of breach of marriage, of sleep and of death.

645谨慎地，就像每一次进入一座房子（他自己的或并非他自己的）的时候那样，小心翼翼地，因为床垫子那蛇状螺旋弹簧已经陈旧了，黄铜环和蝰蛇状拱形挡头也松松垮垮的，一用力过头就颤悠；顾虑周到地，就好像进入肉欲或毒蛇的巢穴或隐身之处似的；轻轻地，省得惊动她；虔诚地，因为那是妊娠与分娩之床，合卺与失贞之床，睡眠与死亡之床。

The shearing work of two mutually twisted flat screw wires is a key link in the design of rhombic metal mesh weaving machines.

两根互绕扁螺旋钢丝的剪切作业是菱形金属网编织机设计中的关键一环。

A new method, step-search-diameter ,is presented to calculate the diameter of undirected double-loop networks G.

提出新的无向双环网络G的直径求解法———分步法；并得到一种新的直观图———螺旋环，研究了螺旋环的性质；给出了无向双环网络的直径d的显式公式；给出了N，s都固定的直径算法；在N固定，且2≤r

In this paper,- and (5)-2,2'-diethynyl-1,1'-binaphthyl with highly stable chiral configurations were employed as structural templates, and a new type of helical cyclophane compounds-3 and-3 were synthesized in enantiopure form by the introduction of benzyl sulfone through Sonogashira coupling reaction, followed by the treatment of disulfone with lithium diisopropylamide.

基於2，2'-二取代的联萘衍生物在手性构型上高度稳定的特点，分别从光学活性的-和-2，2'-二乙炔基-1，1'-联萘结构模板出发，通过Sonogashira偶连反应导入苄基碸，然后用二异丙基氨基锂处理制得的联萘二碸成功地合成了一种新的螺旋环芳分子－对映异构体-3和-3。

Based on the basic theroy of fluid dynamics, this paper establishes a model of flow mechanics for turbulent flow, then uses this model to carry on a numerical simulation study on the conventional auger drill stabilizer annular flow field.

基于流体力学基本理论，本文建立了一套钻柱稳定器湍流模式力学模型，并采用该模型，对气体钻井常规螺旋钻柱稳定器环空流场进行了数值模拟研究。

With the help of modern computational fluid dynamics tecnology, this thesis carries on a numerical simulation of annulus multiphase flow of the conventional auger drill stabilizer; it points out the deficiency of the annulus gas in cutting-carrying and lifting; and attempts to develop a drill stabilizer that are suitable for the gas drilling.

本文试图借助现代计算流体力学技术，对常规螺旋钻柱稳定器环空多相流动规律进行数值模拟研究，指出在环空气体携岩举升方面存在的不足，开发一套适合于气体钻井的新型钻柱稳定器，提出全井段环空流场改善方法，实现气体钻井防斜打快，减少冲蚀，提高井眼净化能力的目的。

Neither the killing of Mr Zarqawi nor any breakthrough on the political front will stop the insurgency and the fratricidal murders in their tracks.

在对危险的南部地区访问时，他斥责什叶派民兵领导人对中央集权的挑衅行为。

In fact,I've got him on the satellite mobile right now.

实际上 我们已接通卫星可视电话了