三键

According to element bonding parameter topological index and calculate topological index of 36 variety metal ions.

本文应用元素键参数拓扑指数计算了36种金属离子的拓扑指数，用于关联金属离子与氨三乙酸配位稳定常数的研究，得到了好的线性相关性。

The crystal belongs to triclinic, space group P-1 with α=0.775 1(2) nm, b=0.837 7(2) nm, c=1.003 7(2) nm,α=75.57(3),β=83.05(3),γ=86.08(3), D=1.296 g/cm^3, Z=2, F(000)=256,μ=0.095 mm^(-1), and the final deviation factor R=0.0545 and wR=0.146 0. X-ray analysis reveals that molecules are linked by intermolecular O-H…O hydrogen bonds formed between the adjacent molecules.

具体测定结果如下：该晶体属于三料晶系，P-1空间群，α=0.7751 (2) nm， b=0.8377 (2) nm， c=1.0037 (2) nm，α=75.57 (3)，β=83.05 (3)，γ=86.08 (3)， D=1.296 g/立方公分，Z=2， F(000)=256，μ=0.095 mm^(-1)，最终偏差因子分别为R=0.0545，wR=0.1460.X-射线衍射分析表明，分子之间通过相邻分子间形成的O-H…O氢键相连。

It belongs to triclinic system with space group P-1, a=0.7382(1) nm, b=0.9992(2) nm, c=1.1535(2) nm,α=81.41(2)°,β=85.72(2)°,γ=72.21(2)°, D=1.404 gcm^(-3), V=0.8007(38) nm^(-3), Z=2. The crystal structure shows that the compound has trans configuration and characteristic dimers connected by intermolecular hydrogen bond.

结果表明，该晶体属三斜晶系，空间群P-1，V=0.80070(38) nm^3，Z=2，D=1.404gcm^(-3)，a=0.7382 (1) nm，b=0.9992 (2) nm，c=1.1535 (2) nm，α=81.41 (2)°，β=85.72(2)°，γ＝72.21(2)°，分子结构呈反式构型，通过分子间氢键组装成二聚体。

Vibration analysis show that dimer and trimer have typical red-shift hydrogen bond.

振动分析表明二聚体和三聚体存在典型的红移氢键。

Three stable structures of the dimer and trimer have been obtained by the optimized geometries and frequencies calculation.

构型优化和频率计算得到3个稳定的二聚体和三聚体氢键异构体。

The natural bond orbit analysis shows that the inter-molecular charge transfers are 0.60475e and 1.20225e for the dimer and trimer, respectively.

自然键轨道分析表明，形成最稳定的二聚体和三聚体时，分子间电荷转移分别为

Above all, the pivot issue of this thesis is to synthesize the linear backbone motif of P. syringae, a trisaccharide structure of Rha(1→3) Rha(1→2)Rhap.

基於上述各点，本研究之方向为合成出丁香假单胞菌中主链的部分，即Rha(1→3) Rha(1→2)Rhap的三醣重复键结结构。

We are satisfied that thefive main components were pure and plenty enough for NMR study. The structure and configuration of key component of urushiol weresuccessfully determined by using 〓 and 〓 conventioanl method,DEPTtechnique,homo- and heteronuclear chemical shift correlation 2D-NMR,2D-J resolved NMR,heteronuclear relayed coherence transfer 2D-NMR,and relaxation time measurement.The assignment of resonances for 〓and 〓 were confirmed.

对中国生漆含量最大的关键漆酚组分，在〓常规NMR谱和DEPT编辑谱的基础上，采用同核及异核化学位移相关二维谱，同核J分辨谱和异核中继相干传递二维谱等2D—NMR方法，并结合弛豫时间〓测定技术等，完全确定了占中国生漆总量60%左右的有两双键共轭的三烯漆酚的结构与构型。

The synthesis and characterization of asymmetric dinuclear and mononuclear vanadium complexes show that the pH value is very important for the products\' formation and isolation. In some pH range, theα-alkoxy bridge was easy to break and form asymmetric dinuclear and mononuclear vanadium structure.

三、不对称的双核钒和单核钒配合物的合成和表征显示，pH值对产物的形成和分离具有至关重要的作用。pH值在一定范围内，柠檬酸的烷氧基氧作为桥氧的化学键才容易断开，从而形成不对称的双核钒和单核钒结构。pH值不仅影响不对称双核V_2O_3钒配合物和单核钒配合物的形成，还关系到钒还原的速度。

Methods and Results— We synthesized the 3 components of a gene vector binding complex:(1) A poly allylamine bisphosphonate with latent thiol groups,(2) a poly ethyleneimine with pyridyldithio groups for amplification of attachment sites , and (3) a bifunctional (amine- and thiol-reactive) cross-linker with a labile ester bond.

方法和结果—我们综合了基因复合物载体的三种成分：(1)巯基聚丙烯胺二碳磷酸盐化合物，(2)能扩增结合位点聚乙烯亚胺-pyridyldithio复合物，(3)具有不稳定酯键的双功能交联剂。

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