记忆方法
将“alder”与“Old”结合记忆，想象一个古老的树林（old forest）中有一棵树（alder），通过这样的画面联想，可以更容易地记住单词“alder”（白桦树）。
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中文词源
alder 桤木
来自PIE *el, 树名。
英语词源
- alder
-
alder: [OE] Alder is an ancient tree-name, represented in several other Indo-European languages, including German erle, Dutch els, Polish olcha, Russian ol’khá, and Latin alnus (which is the genus name of the alder in scientific classification). Alder is clearly the odd man out amongst all these forms in having a d, but it was not always so; the Old English word was alor, and the intrusive d does not begin to appear until the 14th century (it acts as a sort of connecting or glide consonant between the l and the following vowel, in much the same way as Old English thunor adopted a d to become thunder). The place-name Aldershot is based on the tree alder.
- alder (n.)
- tree related to the birch, Old English alor "alder" (with intrusive -d- added 14c.; the historical form aller survived until 18c. in literary English and persists in dialects, such as Lancashire owler, which is partly from Norse), from Proto-Germanic *aliso (cognates: Old Norse ölr, Danish elle, Swedish al, Dutch els, German erle), from *el-, the ancient PIE name of the tree (cognates: Russian olicha, Polish olcha, Latin alnus, Lithuanian alksnis).
权威例句
- 1. Modification for synthetic purposes on the Diels - Alder adducts 56 and 62 has only rarely been considered.
- 为了达到合成的目的,对Diels-Alder加 成物(56)和(62)加以改造的问题很少有人考虑.
- 2. Diels — Alder reaction is one of the important research content in the fields of organic chemistry.
- Diels—Alder反应是目前有机化学领域重要研究内容之一.
- 3. Activated olefinic bond Amine, thiol radical initiator, cationic initiator, dienes ( Diels - alder reactive ).
- 活性烯键胺, 巯基,引发剂, 阳离子引发剂, 烯烃 ( 的Diels-Alder反应 ).
- 4. They were principally used to catalyze aldol, allylation, Diels - Alder, ene and Friedel - Crafts reactions.
- 它们主要被用来催化Aldol, 烯丙基化, Diels-Alder, Ene和 Friedel -Crafts等反应.
- 5. Diels - Alder reaction of 2 - merhylene - 1 - pheny 1 - 1.3 - butanedione catalysed by zinc chloride as lewis acid with 1.3 - cylcopentadiene was reported.
- 以氯化锌为路易斯酸催化剂,探讨了2 ─ 亚甲基─1 ─ 苯基 ─ 1.3 ─ 丁二酮与1.3 ─ 环戊二烯的Diels─Alder反应.
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