取代物

The dechroming mechanism of organic acid from chrome shavings was studied from the following aspects,the depolymerization of complex compound,the replacement of H+ and the replacement of organic acid radical anion.

从络合物解聚、氢离子取代和有机酸根阴离子取代3个方面，探讨了有机酸的脱铬机理，认为氢离子的取代和有机酸阴离子的取代起主要作用。

We have studied the transition metal complexes catalyzed sequential cross coupling reactions of these new difunctional group reagents with electrophiles and nucleophiles, respectively; developed some convenient and practical new methods for the stereoselective synthesis of disubstituted alkenes, trisubstituted alkenes, conjugated dienes containing heteroatom, conjugated enyne containing heteroatom etc., enriching methodologies for organic synthesis.

继而研究了这些新型双官能试剂在过渡金属配合物催化下分别与亲电试剂、亲核试剂的顺序交叉偶联反应，为双取代烯烃、三取代烯烃、杂原子取代的共轭二烯烃、杂原子取代的共轭烯炔烃等的立体选择合成提供了方便实用的新方法，丰富了烯烃立体选择合成的方法学。

The results indicate that thermal stabilities and decomposition mechanisms of the title compounds derived from the BDE, Ea and static electronic parameters are basically consistent. Homolysis of the N—NO2 bond is the initial step in the thermolysis of the title compounds, the meta-isomers are more stable than the para-isomers, and the ortho-isomers are the most sensitive.

结果表明，由BDE、Ea和静态电子结构参数推断的标题物热稳定性和热解机理的结论基本是一致的，N-NO2键均裂是标题物的热解引发步骤，间位取代异构体较对位取代异构体稳定，而邻位取代的异构体稳定性最差。

Synthesis of target compounds namely: to vanillic acid as the starting material with methanol under reflux conditions for 4 - hydroxy -3 - p-methyl, then ether, and nitration, reduction, cyclization reaction 6 - methoxy -7 - benzyloxy-quinazoline -4 - one, and then by the chloride in place of aniline, benzyloxy-off, such as etherification reaction of the target compounds; target compounds with the second and third occurrence of substitution reactions of amines by the TM1, that is, 4 - amino-benzene -6 - methoxy -7 - [2 - hydroxy -3 -(N, N-diethyl amino) oxy c] quinazoline; with ether occurred Ornidazole reaction of TM2, namely, 4 - amino-benzene -6 - methoxy -7 - [2 - hydroxy -3 -(2 - methyl -5 - nitroimidazole) C oxy] quinazoline.

本论文以嘌呤类似物喹唑啉为母核，分别在其4位和7位引入结构多样的取代苯氨基和柔性侧链，设计了一系列4-取代苯胺基-6-甲氧基-7-(2-羟基取代丙氧基)喹唑啉类化合物。目标化合物的合成即：以香草酸为起始原料，与甲醇回流条件下得到4-羟基-3-甲氧基苯甲酸甲酯，然后经过醚化、硝化、还原、环合反应得到6-甲氧基-7-苄氧基喹唑啉-4-酮，然后再经氯化、取代苯胺、脱苄氧基、醚化等反应得到目标化合物；目标化合物与二乙胺发生胺取代反应得到了TM1，即4-苯氨基-6-甲氧基-7-[2-羟基-3-丙氧基]喹唑啉；通过与奥硝唑发生醚化反应得到TM2，即4-苯氨基-6-甲氧基-7-[2-羟基-3-(2-甲基-5-硝基咪唑)丙氧基]喹唑啉。

After treated with CuAz, the hydrogen from phenolic hydroxyl group in lignin was replaced by Cu from treated solution, being N-Cu-O complex, or two of the ammonia ligands of the tetrammine complex were replaced by copper-oxygen bonding from hydroxyl, being Cu-N-lignin complex.

在铜唑防腐剂处理后，木质素上酚羟基的H可以被Cu取代，形成&N-Cu-O&形式的络合物；或者处理液中四氨络合物中的2个氨配体被羟基取代，形成芳香族-铜络合物。

All the ligands and complexes have been characterized with ~1H-NMR, MS and EA.X-Ray single crystal diffraction reveals that zirconium complex containing the tert-butyl substituted N_2O_2 ligand is an oxo- and hydroxyl-bridged dinuclear structure, which is possibly formed by partial hydrolysis of chlorides at one of the zirconium centers. A tetranuclear zirconium complex has been obtained and chacaterized, which is formed by complete hydrolysis of the chlorides at the zirconium centers.

通过研究配合物的单晶结构，我们发现叔丁基取代的不对称N_2O_2配体与ZrCl_4反应生成的锆配合物为氧桥和羟基桥连接的双核锆配合物，中间过程涉及单核锆配合物中氯原子部分水解，并得到氯原子部分水解的双核锆配合物和全部水(来源：8e6eAB67C论文网www.abclunwen.com)解的四核锆配合物的晶体结构，在晶体培养过程中发现双核锆配合物能够以手性自发拆分结晶析出。

An optically clear thermoplastic resin composition consisting essentially of: structural units derived at least one substituted or unsubstituted polycarbonate, at least greater than 30 weight percent of a substituted or unsubstituted polyester, a modified polycarbonate, an impact modifier having a refractive index in the range between about 1.51 and about 1.56 and an additive is disclosed.

公开了一种光学透明热塑性树脂组合物，该组合物基本上由以下组成：结构单元衍生的至少一种取代的或未取代的聚碳酸酯，至少大于30wt％的取代的或未取代的聚酯，改性的聚碳酸酯，折射率范围为约1.51～约1.56的抗冲改性剂和添加剂。

The hydrolysates from oat xylan using Xyn Ⅰ Xyn Ⅱ and their mixture for hydrolysis were analysed by HPLC. It was showed that Xyn Ⅰ hydrolyzed mainly the unsubstituted regions of oat xylan, and hydrolytes were high xylooligosaccharides; whereas Xyn Ⅱ exhibited greater catalytic versatility than Xyn Ⅰ and were able to attack substituted regions of the polysaccharide and showed greater activity to low xylooligosaccharides than Xyn Ⅰ to give xylobiose as the main hydrolysate. The purified xylanases were acidic enzymes.

以纯化酶组分及其混合物水解燕麦木聚糖，采用高效液相色谱分析相应的水解产物，结果表明，Xyn Ⅰ降解燕麦木聚糖时，主要降解作用发生在底物中没有取代基的区域，水解产物的聚合度较高；Xyn Ⅱ对底物具有更强的适应性，能降解底物中有取代基的区域，相对Xyn Ⅰ酶组分，Xyn Ⅱ酶组分对低聚合度的木聚糖的活性更高，木二糖为主要降解产物。

The spectroscopic properties (λ〓〓,λ〓〓,φ,τ, k〓, k〓) of 〓 were also measured. It was found that the energies of absorption and emission maximum is red-shifted for both electron-withdrawing and electron-donating substituents compared to that of parent 〓 complex.

发现无论X是吸电子取代基还是给电子取代基，配合物的吸收峰和发射峰与母体化合物〓相比均向红移；常温下，具有吸电子基的配合物与具有给电子基的配合物相比，有较高的发光量子产率和长的激发态寿命。

The coordinated COD of 3 and 4 can be replaced by carbon monoxide to yield the corresponding dicarbonyl species [(C,N-pyN^C-R) M2]BF4 (14, M= Rh; 15, M= Ir). Ligand substitution of 11a by phosphines and azide causes the de-complexation of pyridinyl-nitrogen donor to generate the corresponding carbene rhodium complexes [(C-pyN^C-Mes)RhPR3] (17a, R = Ph, 17b, R = Et) and [RhN3] (19), respectively, indicating the labile nature of steric-hindered pyridinyl-nitrogen donor.

螯合错合物的吡啶配位，可以容易被σ-予体，如卤离子、叠氮阴离子、膦试剂，置换；但是铑与铱金属螫合物与π-酸试剂，如一氧化碳、异腈，则发生COD被置的产物14a与16；与三甲基亚磷酸酯反应时，COD及吡啶均会被取代而得到单芽的三铑-碳烯错合物18；双膦化合物则会取代铑金属上全部的配位基。

In the United States, chronic alcoholism and hepatitis C are the most common ones.

在美国，慢性酒精中毒，肝炎是最常见的。

If you have any questions, you can contact me anytime.

如果有任何问题，你可以随时联系我。