查询词典 reaction ring

The intermediate decyl-glycidol ether of Gemini phosphate surfactant was synthesized with decanol and epichlorohydrin in the presence of phase-transfer catalyst; the intermediate decyl digomeric glycol of Gemini phosphate surfactant was prepared by opening ring reaction of decyl glycide ether and glycol in the presence of potassium as catalyst; and the influence of type and dosage of phase-transfer catalysts was studied.

以正癸醇与环氧氯丙烷为原料在相转移催化剂存在的条件下合成Gemini磷酸酯表面活性剂的中间体I-正癸基缩水甘油醚，讨论催化剂种类及用量对反应的影响；以乙二醇和正癸基缩水甘油醚为原料，金属钾为催化剂合成Gemini磷酸酯表面活性剂的中间体Ⅱ-正癸基低聚二醇，讨论催化剂种类与用量对反应的影响；以P2O5与正癸基低聚二醇为原料合成Gemini磷酸酯表面活性剂，讨论投料比、反应温度和反应时间等因素对反应的影响。

In the second part of this thesis, a formal [2+2] cycloaddition ketenes and dialkyl azodicarboxylates was studied. We found that by adjusting the substituents in the diazenes, the reaction mode can be completely switched, and furnish four-membered-ring products, aza-b-lactams, the enantioselectivity was up to 91%.

经研究发现，通过对偶氮化合物取代基团的改变，我们可以实现[4+2]环加成反应到[2+2]环加成反应的转变，在手性氮杂环卡宾的作用下，对具有各种取代基的烯酮都可以很好的产率得到氮杂b-内酰胺，其对映选择性最高可以达到91%。

OBJECTIVE: To construct discitis animal model by destroying the fibrous ring and the cartilage lamina through the surgery, in addition, to explore the changes of autoimmune reaction.

目的：通过手术破坏纤维环和软骨终板建立椎间盘炎的动物模型，探讨自免疫状态表达变化过程。

The paper aimed at seismic response and uplift of vertical storage tank, the reaction of base and soil are considered, damping and costing-energy researches are processed which circular-ring energy dissipater is adopted. The simple mechanical model of control system is established, and movement equations are given.

针对立式钢制储罐地震响应及提离效应问题，考虑基础与土壤的相互作用，采用圆环耗能器进行减小地震响应、降低提离的控制研究，建立了控制体系的力学分析模型，并给出了运动分析方程。

Molecular rearrangement reaction occurs during the foaming and post-treatment forming hexahydric imide ring. The prepared PMI foams have closed cell structure with the cell size ranging from 0.5mm to 0.7mm and have a good thermostability with the characteristic degradation temperature at about 221.5℃.

在发泡和热处理过程中分子链发生分子重排反应，生成六元酰亚胺环结构；PMI泡沫为闭孔泡沫塑料，泡孔平均孔径在0.5~0.7mm之间；制得的泡沫塑料热稳定性好，热分解温度在221.5℃左右。

This o-quinone could isomerize to p-quinone methylene compound at low scan rates. The C3 hydroxyl group at ring C oxidized next was shown to undergo an irreversible oxidation reaction. This oxidation became the main oxidation peak during the following cyclic potential scans, due to an especial product-absorption mechanism.

在电势扫描速度较慢时该邻醌可异构化为对醌亚甲基化物。C环C_3羟基在稍高的电位发生不可逆的氧化过程，并且在后续的循环扫描过程中通过独特的产物吸附机理而成为主氧化峰。

Based on B-trichloroborazine with boron-nitrogen ring structure, the monomer was synthesized by substitution reaction with different molar ratio of propylamine/isopropylamine, then the corresponding polyborazine was obtained through thermal polymerization.

以三氯环硼氮烷为原料，将其与正丙胺/异丙胺进行共取代反应，制得了不同结构的取代单体，再经热聚合反应获得了相应的聚硼氮烷先驱体。

Based on B-trichloroborazine with boron-nitrogen ring structure, the monomer was synthesized by substitution reaction with different molar ratio of propylamine/isopropylamine, then the corresponding polylyborazine was obtained through thermal polymerization.

以三氯环硼氮烷为原料，将其与正丙胺／异丙胺进行共取代反应，制得了不同结构的取代单体，再经热聚合反应获得了相应的聚硼氮烷先驱体。

The first synthetic route uses 1,2,4-trimethoxybenzene and chloroacetonitrile in forming 2,4,5-trimethoxy-a-chlor-acetophenone under the anhydrous condition, then the intermediate condensates with papaverine forming the core pyrro[2,l-a]isoquinoline, followed by formation and lactonization to form the lactone ring. The second synthetic route uses prepared aldehyde with prepared ethyl nitroacetate by Knoevenagel condensation to obtain 2-Nitro-3-(2,4,5-tris-methoxy-phenyl)-acrylic acid ethyl ester and 2-Nitro-3-(2,4,5-tris-benzyloxy -phenyl)-acrylic acid ethyl ester etal intermediates. The lamellarin skeleton could arise from condensation of the papaverine and these intermediates by Michael reaction, the ester group is provided for subsequent lactonization. The third synthetic route uses coumarin or indan-l,3-dione derivatives and papaverine to form lamellarin under basic conditions.

第一条路线首先从1，2，4-三甲氧基苯出发与卤乙腈作用合成卤代芳酮中间体，然后与罂粟碱反应合成开链片螺素，最后经乙酰化、去保护、成内酯环得到片螺素；第二条路线由制备的芳醛和制备的硝基乙酸乙酯经缩合得到2-硝基-3-芳基丙烯酸乙酯，然后由该中间体与罂粟碱反应，在完成关环的同时也引入酯基，最后去保护、成内酯环得到片螺素；第三条路线是由香豆素或茚二酮出发，经溴代后的中间体与罂粟碱反应，得到片螺素的基本框架。

In this paper, the polymerization kinetics, reaction mechanism, viscosity, molecular weight and MWD of the ring-opening polymerization of cyclosiloxane in the presence of water will be investigated expermentally and analyzed mechanistically in detail.

就具体内容而言，本论文主要进行了以下几个方面的工作：建立反应混合物转化率与凝胶渗透色谱谱图峰面积的标准曲线，采用GPC测定反应混合物转化率和聚合物的分子量及分布。

Since historical times,England ,where the early inhabitants were Celts, has been conquered three times .

从有历史以来，英国，在此地早期居住的是凯尔特人，已经被征服了三次。

Bluetooth OBEX File Transfer Enables the sending and receiving of files on your phone via Bluetooth.

蓝牙OBEX文件移动允许经过蓝牙传送和接受文件。。。。