乙烯的

objective to determine the contents of residual acetone in acetoacetic ester,the raw material for the synthesis of edaravone, by gas chromatography.methods sample solution was injected on a gdx column (0.18 mm～0.25 mm) with nitrogen as the carrier gas.the residue was calculated by the external standard method.results the linearity was good over the range of 25 μg/ml～400 μg/ml,with the correlation coefficient of acetone being 0.996 and the average recovery 96.8%.conclusions the method was proved to be simple,rapid,practical and highly sensitive.it is an efficient method for the quality control of acetoacetic ester.

摘要］ 目的：用气相色谱法测定依达拉奉合成起始原料乙酰乙酸乙酯中丙酮的残留量。方法：采用固定相为二乙烯苯乙基乙烯苯型高分子多孔小球（直径为0.18 mm～0.25 mm），氮气为载气，用外标法测定乙酰乙酸乙酯中残留丙酮的含量。结果：该方法在丙酮浓度范围在25 μg/ml～400 μg/ml内呈良好的线性关系，响应曲线相关系数为0.996，平均回收率为96.8%。结论：本法简便，快速、实用，灵敏度高，可有效地用于乙酰乙酸乙酯的质量控制。

The invention provides a method for homopolymerizing conjugated dialkene or co-polymerizing conjugated dialkene and monovinyl aromatic hydrocarbon. The method comprises the following steps: the conjugated dialkene is homopolymerized or the conjugated dialkene and the monvinyl aromatic hydrocarbon are co-polymerized randomly. The method is characterized in that at least one alkali metal alkoxide compound expressed by the formula is used as a structure regulator; in the formula, R is linear chain or branched chain alkylidene radical having 1 to 10 carbon atoms; M is alkali metal selected from Li, Na, K, Rb and Cs.

本发明提供了一种使共轭二烯烃均聚或者使共轭二烯烃与单乙烯基芳烃共聚的方法，包括在阴离子聚合条件下使共轭二烯烃进行均聚或者使共轭二烯烃与单乙烯基芳烃进行无规共聚，其特征在于采用至少一种式所示的碱金属醇盐化合物作为结构调节剂，其中R为具有1-10碳原子的直链或支链亚烷基；以及M为选自Li、Na、K、Rb和Cs的碱金属。

The results of CRYSTAF test showed,along with the increment of the ethylene content,an increase in the tacticity of propylene homopolymers and decreases in the isotacticity、long crystallizable sequence content.

结晶分级分析测试结果显示，随着乙烯含量的增加，聚丙烯均聚物部分链结构规整性提高，结构规整、可结晶的长序列含量在减少，可见乙烯含量的变化规律直接决定上述参数的变化规律。

The reaction proceeds by ethene chemical adsorption to form the surface ethoxide and the C-C bond formation between the ethoxide and the second ethene molecule to form the butoxide product.

乙烯化学吸附生成的烷氧化合物与物理吸附的乙烯分子发生二聚反应生成新的C-C键同时生成新的烷氧化合物。

Methanol hydrochlorinate has two steps: one is to produce monochloro methane by methanol hydrochlorinate reaction and the other is to make monochloro methane produce polychlorinated methane.

二硫化碳法、氯油法和乙醛法因不经济和环保问题在国外已被淘汰；C1一C3废氯烃全氯化法是利用氯乙烯等装置的副产废料生产四氯化碳并联产四氯乙烯，该法是一种非常经济的工艺，在国外曾被十分广泛地采用，但随着发达国家四氯化碳的停止使用，目前大部分基于该工艺的装置被迫停产。

Thirdly, The preparation of 3-aryl-5-substituted-ethenyl isoxazoles and l-isoxazolyl-2-isoxazolinyl substituted-ethenes was developed through 1, 3-dipolar cycloaddition of nitrile oxides,α-alkylation reaction and another 1, 3-dipolar cycloaddition of nitrile oxides based on polystyrene-supported propargyl selenide.

三、从聚苯乙烯负载的炔丙基硒醚出发，经过腈氧化物的1，3-偶极环加成反应、α-烷基化反应和腈氧化物的1，3-偶极环加成反应固相分别合成了3-芳基5-取代--乙烯基异噁唑和1—异噁唑—2—异噁唑啉取代的-乙烯。

The first step in the degradation is most probably the classical ester scission reaction to give a carboxylic acid and olefinic end groups. Further ester scission on the adjacent ester groups of carboxylic acid and olefinic molecular chains can then lead to the formation of lower weight pyrolytic products, such as: CH〓=CHOCOPhCOOCH=CH〓、CH〓=CHOCOPhCOOH and HOOCPhCOOH, and they can pyrolyze continually to produce substrate pyrolytic compounds, such as: HOOCPhCOCH〓、PhCOOH、PhH、PhCOCH〓 and CO、CO〓. At the same time, a corsslinking cyclization reaction occurred of the formation of the gas products during the degradation of PET.

断裂大分子链端邻近羰基和乙烯基的酯键持续断裂，不断地形成小分子裂解产物，如：CH〓=CHOCOPhCOOCH=CH〓、CH〓=CHOCOPhCOOH以及HOOCPhCOOH，这些产物还会进一步裂解成分子量更低的小分子裂解产物，如：HOOCPhCOCH〓、PhCOOH、PhH、PhCOCH〓以及CO、CO〓等，与此同时，一部分乙烯基酯端基的大分子链碎片会发生支化而相互连接，再经&链脱离&和环化反应形成难燃的交联产物。

By way of orthogonal testing analysis,study was carried out on effects of molar ratio of unsaturated monomers with carboxylic groups,sulphonic groups,polyoxyethylene side chain groups and mean degree of polymerization of polyoxyethylene side chain groups on performance of polycarboxylic series of water reducer.

采用正交试验分析法，研究了带活性基团羧基、磺酸基、聚氧化乙烯链基等不饱和单体的摩尔比及聚氧化乙烯链的聚合度等对聚羧酸系减水剂性能的影响，提出一种合成聚羧酸系高性能减水剂的最佳配方。

The results showed that 22.5μL/L of clove leaf oil had the best preservation effect on peach. After 35 days of stock, the sound fruit rate was 94%, 46.9% higher than compared group. The rotten index and the browning index were 94.1% and 85.2% lower than the control, respectivly, and the treatment could remarkablely reduce the respiration rate and ethylene release, and postponed ethylene release peak and respiration peak 5 and 10d, respectively in comparison with CK, it also delayed the drop of firmness and contents of titrable acids of the peach. When stored for 35d, firmness of control group and 22.5μL/L of clove leaf oil were decreased 60% and 34% compared with initial storage, and the activities of SOD, CAT and POD were enhanced, but the contents of SSC had no obvious difference with control.

结果表明，与对照相比，22.5μL/L丁香叶油处理对桃果实的防腐保鲜效果最好，贮藏35d时好果率为94%，比对照提高了46.9%，腐烂指数和褐变指数分别比对照低94.1%和85.2%；丁香叶油处理可以有效降低桃果实的呼吸强度和乙烯释放量，呼吸强度高峰和乙烯释放量高峰分别推迟5和10d，延缓了果实硬度和可滴定酸含量下降的速度；贮藏35d时对照和22.5μL/L丁香叶油处理果实硬度分别比贮藏初期降低了60%和34%；丁香叶油处理提高了超氧化物歧化酶、过氧化氢酶、过氧化物酶3种膜脂过氧化物酶的活性，但可溶性固形物含量与对照相比无明显差异。

Considering the strength enhancing efficiency of phenol-formaldehyde resin modified by triethylamine and diethylene triamine in OCC pulp, the efficiency of phenol-formaldehyde resin modified by diethylene triamine was better than triethylamine.

综合考察二乙烯三胺和三乙胺改性的酚醛树脂的增强作用，二乙烯三胺作为改性剂时改性的酚醛树脂要优于三乙胺改性的酚醛树脂。

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。