酯

Ethyl 4,4,4-trifluoroacetoacetate was synthesized from ethyl acetate and 4,4,4-trifluoroacetate(mole ratio 3:1) with sodium ethoxide.

乙酸乙酯与三氟乙酸乙酯(摩尔比为3∶1)在乙醇钠作用下进行克莱森酯缩合反应，得到三氟乙酰乙酸乙酯。

The inhibitory potency of geranyl gallate is as about six times as that of lauryl gallate on mushroom tyrosinase. Lauryl gallate was determined to be an uncompetitive inhibitor while geranyl gallate belongs to be a mixed-type inhibitor.

没食子酸香叶酯对蘑菇酪氨酸酶的抑制作用比没食子酸十二烷基酯更强，没食子酸十二烷基酯表现为反竞争性抑制类型，而没食子酸香叶酯表现为混合型抑制类型。

Lactide, glycolide or caprolactone, biodegradable polyester and diisocyanate as materials are first bulk melt polymerized to prepare the degradable polymer with thermal deformation transforming temperature of about 37 deg.c. The obtained material is processed at temperature over melting temperature so as to shape into spiral rack, applied with stress at temperature higher than Ttrans to form shape easily operational handling and frozen to eliminate stress into the product.

本发明以丙交酯、乙交酯或己内酯，生物可降解聚酯及二异氰酸酯为原料，通过本体熔融聚合制备得到热致形变温度转化点在37℃左右的可降解高分子材料，将得到的材料在熔融温度以上进行加工、赋形制作成用于不同管腔内的螺旋管状支架；在T＞T trans 条件下施加应力，加工为便于手术操作的形状；冷冻定型消除应力，即得产品。

The resistance to oxidation of synthetical ferulaic acid glycolipide was investigated. The result was shown, apple was dipped in 0.62% ferulaic acid glycolipide, the most inhibitor effectiveness of glucose ferulaic esters and xylose ferulaic ester was shown respectively to be 36.92% after four days and 19.47% after eight days, the fastigium of release ethane was postponed respectively to be six days and four days.

本文测定了合成阿魏酸糖脂的抗氧化性，结果表明用0.62％的阿魏酸糖脂浸泡的苹果，阿魏酸葡糖酯抑制效应在处理后4天最明显，抑制率 36.92%，阿魏酸木糖酯抑制效应在处理后8天最明显，抑制率为 19.47%对于果实的内源乙烯释放，经阿魏酸葡糖酯和阿魏酸木糖酯处理的苹果分别推迟乙烯释放高峰期6天和4天。

The nautre of ester bond and sedimentary medium condition control the distribution pattern of organic acid ester in strong reductional environment and water-washed oxidized crude oils. The former features higher contents both of 9, 11-Octadecadienoic acid, methyl ester and Hexadecanoic acid, showing the non-reversible hydrolysis reaction of ester bond in condition of basicity; the later features higher contents of Hexadecanoic acid and Octadeanoic acid, and lower contents of nonsaturated and side-chain acid ester, indicating the reversible hydrolysis reaction of ester bond in acid condition.

酯键的化学性质和沉积环境中介质条件，决定了强还原咸水盐湖相和淡水湖沼相经水洗氧化次生变化的原油有机酸酯的分布特征，前者9，11-十八二烯酸甲酯与正十六烷酸为主，反映酯键在碱性条件的不可逆水解过程，后者以正十六烷酸和正十八烷酸为主，烯酸和支链酸很少，反映酯键的酸性条件的可逆性水解，烯酸经氧化向正十八烷酸，正十六烷酸转化。

The obtained CBC was further reacted with stearic acid at 140℃ and hexadecyl alcohol at 180℃ in turn to form citric acid-beta-butylene glycol-citric acidstearic acid-hexadecyl alcohol claw large molecule.

以1，3-丁二醇、柠檬酸为原料，设计、合成了以1，3-丁二醇为核心的柠檬酸－1，3-丁二醇－柠檬酸爪状物小分子；再用酯化反应依次与带有功能化集团的硬酯酸、十六醇接枝合成了多元酯类爪形大分子柠檬酸－1，3-丁二醇－柠檬酸－硬酯酸－十六醇。

Acrylic acid and ester mainly is acrylic acid, methyl acrylate, ethyl acrylate, butyl acrylate, isobutyl acrylate, etc.

丙烯酸及酯主要是指丙烯酸、丙烯酸甲酯、乙酯、丁酯、异辛酯等。

With LaCl_3·7H_2O as catalyst to replace conventional liquid inorganic acid,and the esterificationbetween isobutyric acidand n-butyl alcohol as a probe reaction,the optimum conditions were investigated and various isobutyrate s were synthesized over it in this paper.

7H2O替代传统液体无机酸为催化剂，以合成异丁酸正丁酯为探针反应考察催化酯化反应的优化条件，并在此条件下合成了多种异丁酸酯，比较了不同催化剂对催化合成异丁酸正丁酯的影响。

Based on this curve the isocyanurate content in polyisocyanurate foam could be calculated, simply depending on a FTIR-ATR spectrum.

利用GPC测定标准样品的异氰脲酸酯含量，结合ATR谱图中异氰脲酸酯吸收峰的强度得到外标工作曲线，以此为基础利用FTIR-ATR技术测定聚异氰脲酸酯泡沫中异氰脲酸酯三聚体含量。

Two kinds of cross-linked polyacrylate latices with relatively narrow distribution of particle diameters, which are abbreviated to P and P/P, were synthesized by seeded emulsion co-polymerization, respectively. Butyl acrylate and 2-ethylhexy! acrylate were used as comonomers of ACR core, styrene and methyl methacrylate were employed as comonomers of ACR shell, and 1,4-butanediol diacrylate was used as cross-linking agent.

采用丙烯酸丁酯和丙烯酸2-乙基己酯(2-EHA)为核层单体、苯乙烯和甲基丙烯酸甲酯为壳层单体、1，4-丁二醇二丙烯酸酯为交联剂，通过多步种子乳液聚合方法合成了P、P／P两种具有窄粒径分布的共聚丙烯酸酯胶乳。

According to the clear water experiment, aeration performance of the new equipment is good with high total oxygen transfer coefficient and oxygen utilization ratio.

曝气设备的动力效率在叶轮转速为120rpm～150rpm时取得最大值，此时氧利用率和充氧能力也具有较高值。

The environmental stability of that world - including its crushing pressures and icy darkness - means that some of its most famous inhabitants have survived for eons as evolutionary throwbacks, their bodies undergoing little change.

稳定的海底环境─包括能把人压扁的压力和冰冷的黑暗─意谓海底某些最知名的栖居生物已以演化返祖的样态活了万世，形体几无变化。