查询词典 esters

Refineesterification with advanced technology and granulation technology, relying on sophisticated production equipment and improve the analytical tools, produces high quality PVC plasticizers, plastic particles and other fine chemical products, including plasticizers Products including phthalate esters, benzene Sanjia esters, adipate esters, maleic acid ester and citric acid ester.

梁溪精化拥有先进的酯化技术和造粒技术，依靠精良的生产设备和完善的分析手段，生产高质量的聚氯乙烯增塑剂、塑料粒子和其它精细化工产品，其中增塑剂产品包括苯二甲酸酯、苯三甲酸酯、己二酯酯、马来酸酯以及柠檬酸酯。

Method］ First of all,esters and lactone reacted with hydroxylamine and formed hydroxamic acid under alkaline conditions; secondly,hydroxamic acid reacted with Fe3+ and generated amaranthine hydroxamic acid-iron complex; finally,esters and lactone contents were measured indirectly at the wavelength of 506 nm.

方法］首先，酯和内酯在碱性条件下与羟胺反应生成异羟肟酸；然后，在酸性条件下异羟肟酸又与Fe3+络合生成紫红色的异羟肟酸铁络合物；最后，在506 nm波长下间接测定酯和内酯含量。

Firstly,saponifying of caustic potash and fatty acid ether esters to convert partial neutral fatty acid soap to emulsifier,and adding sucrose together as emulsifier,making sucrose and fatty acid ether esters come to moloten state at lower temperature,further making interesterification turns out sucrose fatty acid esters at homogeneous phase .

首先使苛性钾与脂肪酸乙酯反应生成部分中性皂作为乳化剂，并加入一定量的蔗糖，使蔗糖和脂肪酸乙酯在较低温度下既可达到相溶状态，进而在均相下发生酯交换反应合成蔗糖酯。

The present invention relates to a coating composition comprising; A at least one polyester oligomer prepared from reactants comprising a 20 60 wt.% of at least one polyol, b 5 30 wt.% of at least one polycarboxylic acid selected from the group of cyclic polycarboxylic acids, the esters or the anhydrides thereof, wherein the carboxyl groups are separated by 3 carbon atoms or less, and from the group of alpha , beta -saturated acyclic polycarboxylic acids, the esters or the anhydrides thereof, and c 20 60 wt % of at least one monocarboxylic acid, the sum of the wt.% indicated for the reactants,, and always being 100 wt.%, and the oligomer being a low-viscosity oligomer having a weight average molecular weight Mw of less than 5,000, and a hydroxyl number in the range of about 200 to about 400 mg KOH/g oligomer, and B at least one polyisocyanate.

本发明涉及一种包含如下组分的涂料组合物：A至少一种由包含如下成分的反应物制备的聚酯低聚物：a20-60wt％至少一种多元醇，b5-30wt％至少一种选自其中羧基被3个或更少碳原子隔开的环状多元羧酸、其酯或酸酐以及选自α，β-饱和的无环多元羧酸、其酯或酸酐的多元羧酸，以及c20-60wt％至少一种一元羧酸，其中反应物、和的wt％之和总是为100wt％，所述低聚物是重均分子量Mw低于5000且羟基值为约200-约400mg KOH/g低聚物的低粘度低聚物，以及B至少一种多异氰酸酯。

Simultaneously, how the gum acacia affects the hydrolysis rate constants of fatty acid esters in 38.6% ethanol solution, and the combination behavior between gum acacia and fatty acid esters have been found. And the way to determine the combination costants between them quantitatively is also found. In addition, the validated quantitative mathematic expression between hydrolysis rate constants of ester and the concentration of gum acacia: k=k'/(1+AM) is verified.

同时研究了38%乙醇溶液中阿拉伯胶与脂肪酸酯之间的缔合行为，并建立了定量确定缔合常数的方法，推导并验证了定量表达酯水解速率常数k与GA浓度关系的数学表达式：k'=k/(1+AM)，得出了GA对脂肪酸酯水解起禁阻作用的结论。

In this paper,firstly a series of acryloxyl derivatives were synthesized from the dehydrogenated abietic acid,a main composition of disproportionated rosin, through acyl chloridation and esterification.The derivatives included the (β-acryloxyl ethyl) esters of dehydrogenated abietie acid,(β-methacryloxyl ethyl) esters of dehydrogenated abietic acid and (β-methacryloxyl propyl)esters of dehydrogenated abietic acid.

论文首先以歧化松香中的主要成分脱氢枞酸为模型化合物，采用酰氯化、酯化手段合成了它的一系列丙烯酰氧基衍生物，包括脱氢枞酸酯、脱氢枞酸(β-甲基丙烯酰氧基乙基)酯和脱氢枞酸(β-甲基丙烯酰氧基丙基)酯。

For example ,the non－ polar materials like hydrocarbons are heavy and draggy as compared to polar emollients,isoparaffins are light and smooth,the polar esters were significantly lighter and smoother,the branched chain and unsaturated esters were exceptionally light and smooth,in the case of straight chain esters,as the emollients become smoother and lighter ,the oiliness increases,in the case of unsaturated and branched chain esters,the emollient becomes lighter ,as well as less oily,when the alcohol chain length is decreased.

研究结果表明，物理化学特性明显影响润肤剂的轻柔感和油亮感，例如类似碳氢化合物的非极性物质相对于极性物质要粘稠些，异构烷烃则轻柔和光滑，带分支链的不饱和酯特别具有轻柔感和光滑感，带分支的不饱和酯相对直链饱和酯在油亮感方面有着特别的不同，直链酯随着产品光滑感和轻柔感的增加，油亮感也增加，对于带分支的不饱和酯而言，产品变得更轻柔，油亮感下降。

Phthalic Acid Esters have been extensive used in industry,and become one of the most widely pollutants in environment.

邻苯二甲酸酯(Phthalic Acid Esters，简称PAEs)是一类重要的有机化合物，在工业上具有广泛的用途。

In contrast, citric acid esters, 810 esters, polyester, trimellitic esters, epoxy esters and other non-toxic, durable and comprehensive performance plasticizers better varieties are developed slowly.

相反，柠檬酸酯、810酯、聚酯、偏苯三酸酯、环氧酯等无毒、耐久、综合性能较好的增塑剂品种则发展缓慢。

In the fifth part, asymmetric synthesis of β,γ-trans-alkenyl α-amino esters was achieved by chiral phosphoric acid catalyzed transfer hydrogenation of β,γ-alkynyl α-imino esters. Utilizing Hantzsch ester as the hydrogen donor, both the alkyne and imine moieties of β,γ-alkynyl α-imino esters were reduced to yield β,γ-trans-alkenyl α-amino esters with up to 96% ee.

第五部分工作中，使用手性磷酸作为催化剂，Hantzsch酯作为氢源，β，γ-炔烃取代的α-酮酸酯亚胺中的炔键和亚胺官能团均被还原，以中等的收率和优秀的对映选择性（up to 96% ee）得到β，γ-反式烯烃取代的α-氨基酸衍生物。

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。