二聚

Six 3,6-dichloropyridazine-derivatized cinchona alkaloid catalysts were synthesized and applied in IFB reaction.

二氢奎宁二聚体2c最差(56%ee)，与环己二酮相比，环戊二酮作为反应原料时，产物的ee值降低。

After a short reaction time most of the monomer will have disappeared and the reaction system will contain a mixture of dimer, trimer and other low polymers

经过短时间反应后，大多数单体消失，反应体系将是含有二聚体，三聚体和其他低聚物的混合物。

D. of the catalyst increased, i. e. the acid volume of the catalyst increased, the conversion for isobutene and the selectivity for trimer increased also, while the selectivity for dimer decreased, and the selectivity for tetramer was almost unchanged.

D。增加时，即催化剂的酸量增加时，异丁烯的转化率和三聚物的选择性也增加，但二聚物的选择性降低，四聚物的选择性则几乎没有变化。

Calcium pimelate, calcium azelate and zinc azelate are prepared by alkali neutralization process, and calcium dimer are prepared using double decomposition reaction, the effect of binary carboxylate heat stabilizer on PVC thermal stability is studied adopting Congo red method and toast with heat method.

通过碱中和法制备了庚二酸钙、壬二酸钙、壬二酸锌，采用复分解反应法制备了二聚酸钙，采用刚果红法与热烘法研究了二元羧酸盐热稳定剂对PVC的热稳定作用。

Both crystallographically unique Zn atoms exit as an octahedral geometry. The four equatorial positions of Zn1 atom are occupied by the carboxylate-oxygen atoms of the two tartrates, and the two oxygens of the left four carboxylate-oxygen atoms coordinate to two different Zn2 atoms, respectively, forming infinite coordination polymer chains. The left two of the trans equatorial positions of Zn2 atom are completed with two oxygen atoms of two water molecules. The axial positions of both Zn atoms are occupied by the nitrogen atoms from different 4,4'-bipyridine molecules to give a 2D rectangular-grid layers with a cavity dimension of 0.51165(3)nm×1.13896(5) nm. A three dimensional network is formed by the crystallization water chains joined by the carboxylate-oxygen atoms through hydrogen-bonding interactions.

两个晶体学独立的Zn原子均为八面体构型，其中Zn1原子赤道配位点被2个酒石酸根中的4个羧酸根氧螯合配位， 2个酒石酸根中剩下的4个羧酸根氧中的2个分别与2个Zn2原子连接形成无限一维链， Zn2原子的另外2个反式赤道配位点被2个水分子氧占据，同时这两种Zn原子的轴向配位点均被4，4'-联吡啶的氮原子占据，形成具有矩形格子[0.51165(3) nm×1.13896(5) nm]的二维层状结构，游离的2个水分子通过氢键作用形成二聚体，并与酒石酸根中未与Zn配位的羧酸氧连接，把二维层状结构连接成三维网状的超分子结构。

The selective linear dimerization of isoprene to formate myrcene in a single phase catalyst solution prepared by mixing two metals, amine, solvent and a small content of isoprene was studied.

摘 要：研究了异戊二烯在两种金属催化作用下均相线性二聚生成月桂烯的影响因素，得到优惠工艺条件：反应温度 13℃，催化剂∶异戊二烯=0 。0 5∶1 0 ，胺∶异戊二烯=0 。0 7∶1.0。

Compound 4 exhibits an unusual 2-D (4,6)-lattice-type network constructed by the [Co222]2- dimers and [Co(H2O)2]2+ units. As for Compound 5, four basic units link to each other form an approximately parallelogrammic pore, which constructed a 2-D covalent bond double-layers network.

化合物4展现出由[Co_2_2_2]~(2-)二聚体和[Co(H_2O)_2]~(2+)组成的具有4、6两种格子的不同寻常的二维网状结构，化合物5以类平行四边形孔道为基本单元构筑了二维共价键网络结构。

But the yields decreased to 71~37％ in n-propanol, i-propanol and i-butanol, with another trimeric byproduct 1-oxo-13c-(2-naphthyloxy)-1, 13c-dihydro-dibenzo xanthenes (29) increasing up to 30％ yield.

而在正丙醇、异丙醇和异丁醇中二苯并咕吨4~6的产率下降至71~37％，另一个二聚体副产物1-氧代-13c-（2-萘氧基）-1，13c-二氢-二苯并-咕吨（29）的含量增加，产率可达30％。

The amplified fragment was inserted into pRSET-A to generate the first double repeat of the precursor gene. By utilizing a pair of isocaudamer BamH I and Bgl II sites, and another downstream Hind III site of plasmid pRSET-A, following a series of simple double digestions and ligation of the resulted products, a series of repeat (3, 4 and 6) precursor peptide fragment genes were derived.

本实验设计一对两侧含编码疏水性氨基酸密码子的引物，经过扩增前导序列10~34aa基因序列，并重新克隆入质粒pRSET-A构建串联二聚体后，再利用质粒pRSET-A的BamH I / Bgl II同尾酶克隆位点，经一系列简单的酶切和连接，快速构建这一前导肽中不含组氨酸标签序列的串联多聚体基因，并成功表达其六聚体重组蛋白。

The dimerization is thermodynamically unfavorable by the enthalpy. However, the formations of trimers and tetramers are very favorable thermodynamically even at high (1200 K) temperatures. Comparisons of the thermodynamic parameters of subsequent oligomerization are also given.

由焓变可知，单体形成二聚体在热力学上是不利的，而形成三聚体和四聚体在高达1200 K的温度下是有利的，同时分析比较了后续反应的热力学参数。

Singer Leona Lewis and former Led Zeppelin guitarist Jimmy Page emerged as the bus transformed into a grass-covered carnival float, and the pair combined for a rendition of "Whole Lotta Love".

歌手leona刘易斯和前率领的飞艇的吉他手吉米页出现巴士转化为基层所涵盖的嘉年华花车，和一双合并为一移交&整个lotta爱&。

This is Kate, and that's Erin.

这是凯特，那个是爱朗。