查询词典 pyruvaldehyde

Pyruvaldehyde was synthesized with acetone or 1,2 propanediol as starting material respectively.With n∶n=1 00∶0 79,3 0-4 0 g potassium chlorate as catalyst,and water and glacial acetic acid as solvent,refluxing on water bath of 60-75 ℃ for 4 h,bromoacetone was obtained in 63 5% yield.

分别用丙酮和 1，2 丙二醇做原料合成了丙酮醛。n∶n =1 0 0∶0 79，加入 3 0～4 0g氯酸钾做催化剂，水和冰醋酸做溶剂，水浴温度为 6 0～ 75℃，回流 4h ，制得产率为 6 3 5 %的溴丙酮。V∶V =11 9∶1 0 ，通入空气，在 6 5～ 70℃反应 5～ 8h ，制得产率为 5 9 6 %的丙酮醛。

Modified synthesis of furanone from pyruvaldehyde by microwave irradiation was studied.

以丙酮醛为原料采用微波法环化合成呋喃酮。

The total yield of pyruvaldehyde was 37 8%.With npotassium dichromate...

后者为一步法，操作简便，产品纯度较高；产率比前法提高 12 %。

Then with V∶V=11 9∶1 0,and by bubbling of air at 65-70 ℃ for 5-8 h,pyruvaldehyde was produced in 59 6% yield.

丙酮醛的总收率达 37 8%。n∶n∶n(1，2 丙二醇)=1 0∶4 0∶(1 5～ 2 5 )，以水为溶剂，在 6 0～ 70℃间歇通入氮气 1 5h ，边加原料边蒸馏，制得产率为5 0 %的丙酮醛。

However, production of pyruvaldehyde in galactose/glycine system was much less than that in glucose/glycine system at 60°C.

糖类的初浓度对褐变速率之影响，在1.2%~4.8%之间呈线性正相关；其中羊乳糖／甘胺酸系统的褐变速率大於葡萄糖／甘胺酸系统。

Glucose/glycine and galactose /glycine model systems used to study the effects of sugar, temperature and concentration of sugar on Maillard browning and production of pyruvaldehyde.

本研究以葡萄糖／甘胺酸及半乳糖／甘胺酸为模式系统，探讨温度及糖浓度对 pH值。

The yield of pyruvaldehyde in glucose/glycine system (181□g/100ml)was3.6 folds that of galactose/glycine system (50□g/100ml)at 48 hr,We also founded that higher tmeperature promoted the change of pH, which in turn effect more significantly on Maillard reaction.

在丙酮醛产量方面，45°C组葡萄系统在6084小时后才开始产生且量较少；而60°C组葡萄糖系统其产量於48小时达至最高（181□g/100ml），此时丙酮醛的产量为乳糖组（50□g/100ml ）的3.6倍，之后有下降的趋势，其中浓度的效应较不明显。

Dimethyl - 4 - hydroxy - 3(2H) furanone has been synthesized by the hydrogenatic coupling of pyruvaldehyde and cyclization under the basis conditions.

以丙酮醛为原料，在乙酸水溶液中用锌粉氢化二聚，然后在碱性溶液中闭环，合成了一种重要的杂环香料呋喃酮，产率达 2 8.6 %。

Copper pyruvaldehyde bis（N -methylthiosemicarbazone） complex, or Cu-PTSM, belonging to a class of neutral, lipophilic complexes ,is a positron emission tomography radiopharmaceutical that can be used to evaluate blood flow in the heart, brain, and tumors without following any side effect .

Cu-PTSM是中性亲脂性复合物，用于PET显像的放射性药物由于该制剂很容易扩散到细胞内，因此注射Cu-PTSM后可以了解心、脑和肿瘤部位的血流灌注状况，它不伴有副反应的发生，且合成比较容易，所以是一种非常有途的新型PET显像剂。

copper pyruvaldehyde bis（n -methylthiosemicarbazone） complex, or cu-ptsm, belonging to a class of neutral, lipophilic complexes ,is a positron emission tomography radiopharmaceutical that can be used to evaluate blood flow in the heart, brain, and tumors without following any side effect .cu-ptsm has been demonstrated the ability of rapid diffusion into cells.also because it can be synthesized,it is a potential tracer for pet imaging.

作者单位：610041 四川成都，四川大学华西医院核医学科 cu-ptsm是一种中性亲脂性复合物，用于pet显像的放射性药物。由于该制剂很容易扩散到细胞内，因此注射cu-ptsm后可以了解心、脑和肿瘤部位的血流灌注状况，它不伴有副反应的发生，且合成比较容易，所以是一种非常有前途的新型pet显像剂。

Now, however, all children continue in "comprehensive" schools, and the eleven-plus determines which courses of study the child will follow.

然而现在，所有的孩子都要在综合学校继续学习，所以这次考试只是决定他们将要学习哪些课程。

Cultivatable land , and led to a general recognition that development must not be carried at the cost of agriculture .

城区的迅速扩大在很多情况下侵占了宝贵的可耕地，使人们普遍认识到发展不能以牺牲农业为代价。