说明:双击或选中下面任意单词,将显示该词的音标、读音、翻译等;选中中文或多个词,将显示翻译。
您的位置:首页 -> 词典 -> 17-19世纪
1)  In the seventeen to nineteen century
17-19世纪
2)  the end of 19th century
19世纪末
1.
In the end of 19th century and the early 20th century,following wes t ern learning spread to the east,European chemistry education had made its way in to China and set a model for Chinese chemistry education.
19世纪末20世纪初,随着西学东进,化学即已传入我国,为我国化学教育开辟了新纪元。
3)  The 19th century
19世纪
1.
Western movement" offered some foundations for American developing economy in the 19th century and lead to a modern America.
“西进运动”为美国19世纪经济的全面变革和发展准备了条件,并最终导致了一个现代美国的诞生。
2.
The period of European romantic music in the 19th century was a time with its own characteristic and style and the French opera had the features of music in the period.
欧洲19世纪浪漫主义音乐时期是一个极具个性化、风格化的时期,法国歌剧带有这一时期音乐的显著特征。
3.
The linguistics study in China experienced a short brilliance in the 19th century.
19世纪,我国的语言学研究虽有短暂的辉煌,但研究内容仍没有脱离语文学的范围,属语言学的早期发展阶段。
4)  19th century
19世纪
1.
Discussion on international relations of Northeast Asian Countries in 19th century;
19世纪东北亚国际关系刍议
2.
Research on the problem of adoption in 19th century: focused on Anhui province;
19世纪收继问题研究——以安徽为中心
3.
An Analysis of the Motivation and Manner of the British Empire s Overseas Expansion in 19th Century;
"心不在焉"式的版图扩张?——19世纪英帝国海外扩张形式与动因浅析
5)  before 19th
19世纪前
1.
Religious Influence on European Literature before 19th Century;
宗教对19世纪前欧洲文学的介入
6)  Songjiang
19世纪初
1.
"Working All the Year Round":Reality or Exaggeration——A Study of Working Days Per Year of Workers in Major Vocations in Songjiang of the Early Nineteenth Century;
“终岁勤动”:夸张还是现实?——19世纪初松江地区各行业从业人员年工作日数之考察
补充资料:19-Hydroxyandrost-4-ene-3,17-dione
分子式:C19H26O3
分子量:302.41
CAS号:510-64-5

性质:结晶(丙酮/己烷)。熔点170-171℃。[α]D+182°(氯仿)。

制备方法:以醋酸妊娠双烯醇酮(5,16-孕甾二烯-3β-醇-20-酮 3-醋酸酯)为原料,经盐酸羟胺肟化,重排(得醋酸去氢表雄酮)、水解(HCl)、加成、环氧化、水解(脱3-位乙酰基)、氧化(3-位羟基)、消除(脱HCl)、还原、开环等步反应制得。

用途:炔诺酮、炔雌醇的中间体。

说明:补充资料仅用于学习参考,请勿用于其它任何用途。
参考词条