查询词典 ethanal

Simple examples of aldehydes are methanal and ethanal (acetaldehyde, CH3CHO).

简单的醛有甲醛和乙醛（ CH3CHO ）。

Under ultrasonic extraction, comparing the ratio of total alkaloid with 95% ethanal, hloroform, methanol.

用超声波提取法比较了以95%乙醇、氯仿、甲醇为溶剂的提取率，结果依次为1.21%、1.57%、1.54%。

Results Temperature of extractiont and concentration of ethanal had significant effect on the yield of antidepressive substances from Hypericum perforatum L.

结果影响从贯叶连翘中提取抗抑郁成分的主要因素是乙醇浓度与提取温度，贯叶连翘的最佳提取工艺为A4B2C2D1，即20倍量的70％乙醇，80℃回流提取2h。

Glyoxal is prepared with waste liquid propellant HNO3-27S and ethanal .

利用报废的液体推进剂硝酸-27S和乙醛制备乙二醛。

Xylose isomerase plays an important role in industrial ethanal fuel production from lignocellulosic biomass, thus the study on its conformation, function and site-directed mutagenesis is of important prospect and wide attention.

木糖异构在由植物纤维生产酒精工业中扮演著重要角色，对其结构和功能及其改造研究受到广泛重视，具有重要应用前景。

Xylose isomeraseplays an important role in industrial ethanal fuel production from lignocellulosic biomass,thus the study on its conformation,function and site-directed mutagenesis is of important prospect and wide attention.

木糖异构酶在由植物纤维生产酒精工业中扮演着重要角色，对其结构和功能及其改造研究受到广泛重视，具有重要应用前景。

Methods The orthogonal test was conducted to test the effect of the temperature of extraction, time of extraction, concentration and volume of ethanal on extracts yield and the content of hypericins and and total flavonoids from Hypericum perforatum L., and optimize the extraction technology.

方法以总金丝桃素含量、总黄酮含量及浸膏得率为指标，采用正交试验法对提取过程中提取温度、提取时间、乙醇浓度及乙醇用量4个因素进行优选研究。

The headspace gas chromatography was used to determin the ethanal content in the production process of bottle grade PET chip.

论述了瓶级聚酯切片生产过程中，采用顶空气相色谱法测试切片中乙醛含量的称样量、样品处理、颗粒度、顶空热平衡时间、热平衡温度、标定及其他顶空测量参数的优化。

A spectrophotometric simultaneous determination of glutaraldehyde and ethanal based on the reaction between gluaradehyde or ethanal and thiobarbituric acid in acetic acid solution is described.

在醋酸介质中，硫代巴比妥酸与戊二醛及乙醛分别可生成2∶1及1∶1的缩合产物，这两种缩合产物在可见光区具有不同波长的最大吸收，籍此可同时测定戊二醛及乙醛。

To improve the selectivity, the Co/Mn/Br catalyst system with ethanal as an additive was studied and the reaction conditions were also optimized, which were as follows:the amount of ethanal 10%(mole ration base on the substrate), reaction temperature 100℃,reaction time 30min,the oxygen pressure 0.2MPa, the amount of the composite catalyst Co/Mn/Br 7%,the mass ration of different ingredients 2:2:1. Under these conditions, the yield comes to 24.10% and the selectivity reaches 75.03%.

为了提高反应的选择性，论文初步研究了以乙醛作为添加剂条件下各工艺参数的影响，并进行正交优化，得出最佳条件为：乙醛加入量1：10，反应温度100℃，反应时间30min，氧气压力0.2MPa， Co/Mn/Br混合催化剂加入量7%，质量比2：2：1，在此条件下，反应产率为24.10%，选择性可达75.03%。

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。