戊烯

The concentrations of isopentane, 2-methyl-pentane, pentane and 3-methyl-pentane which are from automobile exhaust and gasoline evaporation were highest in alkanes. Benzene/toluene ratio was close to 0.5 which is the characteristic value of automobile exhaust. The concentrations of pinene and isoprene were highest in alkenes.

烷烃类物质中异戊烷、2-甲基戊烷、正戊烷和3-甲基戊烷等机动车尾气或汽油挥发特征性物质浓度最高；芳香烃类物质中苯／甲苯的特征比值略高于机动车尾气排放特征比值0.5；烯烃类物质以植物排放的蒎烯、异戊二烯为主。

There are three isomeric pentene(C5H10)that yield 2-methylbutane on catalytic hydrogenation. Write structural formulas for these three isomers and indicate their relative stabilities based on the ΔH values

答：戊烯的三种同分异构体在催化加氢后可生成2-甲基丁烷，写出3个同分异构体的结构式，并依据他们的ΔH值判断出它们的相对稳定性

The mechanism of the UV-induced photochemically photochromic process of 1,2-bis-(2',5'-bimethyl)-3'-thienyl-perfluoro-cyclopentene was investigated using two-dimensional(2D) FTIR spectroscopy.

利用二维相关红外光谱方法首次研究了1，2-二（2'，5'-二甲基-3'-噻吩）－全氟环戊烯在紫外光照引发下发生光化学闭环反应的历程。

Comparing with marine oils in the adjacent areas, all crude oils in Hade 4 oil field (except for HD401 well) have following peculiarity: very similar in the composition of light hydrocarbon fraction, and the distribution of of phytane-series isoprenoid alkanes, high concentration in steranes, terpanes and their aromatized compounds, as well as rearranged steranes; low concentration of gammacerane, 24-norcholestanes and 24-rearranged steranes, and low C〓 regular steranes C〓/(C〓+C〓+C〓＜20%; 3-methyl steranes and 27-norcholestane predominated, respectively; very low concentration of dinosterane and 4-methyl steroid.

分析表明，与相邻地区海相原油比较，除最南端的HD401井原油外，其它井区原油均具有下述特点：轻烃馏分组成十分接近、植烷系列类异戊烯烷烃分布较为一致、甾萜类和芳香甾萜类环状化合物浓度较高、重排甾烷丰度较高、伽马蜡烷含量低、规则甾烷组成中C〓丰度低C〓/(C〓+C〓+C〓＜20％、甲基甾烷中以3-甲基甾烷为主、甲藻甾烷和4-甲基甾烷丰度极低、降胆甾烷中以27-降胆甾烷为主、24-降胆甾烷和24-重排降胆甾烷丰度低。

Therefore, the research of synthetic method of flavonoids has the important value of scholarship and application.

因此，研究异戊烯基黄酮类化合物的合成方法具有重要的学术和应用价值。

This design which is the injection mould of the glue bottle cap with TPX plastic material to uses the rack-gear, gear-gear drive revolving structure to escaping the thread,and the NC machining process and program of main parts.

本设计采用齿条齿轮、齿轮传动的旋转脱螺纹结构，实现了聚甲基戊烯塑料胶水瓶盖的注射模设计及主要零件的数控加工。

MethodsPolyprenols separated and purified from ginkgobiloba L were administered alone and in combination with 5 Fu,CTX and PDD,and in contrast with 5 Fu,CTX and PDD alone,the experiments were carried out on mouse transplanted Heps and EC.

方法从银杏叶中分离纯化聚戊烯醇，分别与氟脲嘧啶(5 Fu)、环磷酰胺和顺铂联合应用，对移植性Heps和EC荷瘤小鼠进行抑瘤实验，并与 5 Fu、CTX和PDD单独用药比较。

OBJECTIVE To extract the polyprenol homologues from Ginkgo biloba leaves and optimize the separation process.

目的从银杏叶中提取聚戊烯醇同系物并对其提取工艺进行优化。

With structure similar to that of vitamin K, Coenzyme Q10 also known as Ubiquinone 10 is a kind of fatsoluble quinone (C6H4O2), where "10" refers to the number of isoprenyl chemical subunits.

辅酶 Q10又名泛醌10，是一种脂溶性醌，其结构类似于维生素K，因其母核六位上的侧链——聚异戊烯基的聚合度为10而得名，是一种醌环类化合物。

This dissertation is concerned with the approaches to a new high density liquid fuel , tetrahydrotricyclopentadiene, which can be synthesized with dicyclopentadiene as raw materials by three steps: Diels-Alder reaction, separation and hydrogenation.

本文以双环戊二烯为原料，通过双烯加成、分离、加氢反应得到目的产物——新型高密度液体燃料四氢三环戊二烯，主要研究内容包括： 1。三环戊二烯的合成采用两种方式对TCPD的合成进行了研究：DCPD直接热聚法、DCPD与环戊二烯双烯加成法。

We have no common name for a mime of Sophron or Xenarchus and a Socratic Conversation; and we should still be without one even if the imitation in the two instances were in trimeters or elegiacs or some other kind of verse--though it is the way with people to tack on 'poet' to the name of a metre, and talk of elegiac-poets and epic-poets, thinking that they call them poets not by reason of the imitative nature of their work, but indiscriminately by reason of the metre they write in.

索夫农 、森那库斯和苏格拉底式的对话采用的模仿没有一个公共的名称；三音步诗、挽歌体或其他类型的诗的模仿也没有——人们把&诗人&这一名词和格律名称结合到一起，称之为挽歌体诗人或者史诗诗人，他们被称为诗人，似乎只是因为遵守格律写作，而非他们作品的模仿本质。

The relationship between communicative competence and grammar teaching should be that of the ends and the means.

交际能力和语法的关系应该是目标与途径的关系。