异构的

It is reported that alkannin and shikonin isolated from the roots of Lithospermum erthyrorhizon or Alkanna tinctoria and their acylshikonin derivatives are potent selective inhibitors of DNA Topoisomerase Ⅰ.

文献报导紫草素和酰基紫草素等具有DNA拓扑异构酶Ⅰ的选择性抑制活性。本组曾合成得到少量环异紫草素（8），它对小鼠白血病P-388肿瘤细胞具有强烈的抑制作用。

The experimental results showed that the catalyst had better catalytic activity and selectivity. The main product of the isomerization reaction was camphene, and the byproducts were limonene, terpinolene and tricyclene etc.

该催化剂具有较好的催化活性和选择性，异构化反应的主产物是莰烯，副产物是苎烯、异松油烯、三环烯等。

Latest advances in studies on mechanisms for hydroisomerizaton of n-alkane over bifunctional catalysts supported on zeolites,including monomolecular and bimolecular reaction mechanisms, pore mouth mechanism and key-lock mechanisms,were reviewed.

综述了近年来正构烷烃在分子筛为载体的双功能催化剂上加氢异构化反应机理的研究进展，介绍了单分子机理、双分子机理、孔口机理及锁匙机理，并展望了反应机理在制备新型催化剂领域的应用前景。

Studies on the reactions of isomerized products of butaduene and isoprene iron complexes with triphenyl phosphine and triphenyl phosphite

丁二烯-和异戊二烯二羰基铁配合物的异构化产物与三苯膦和亚磷酸三苯酯的反应研究

Safrole oil is nowadays and will be still the main raw material for heliotropine manufacture.Because catalyzation method with potassium hydroxide has merits of cheap material and simple technique , it becomes the sole method to produce isosafrole in domestic factories.

由于氢氧化钾催化黄樟油素异构化法具有原料方便、工艺简单特点，故它是国内工业生产异黄樟油素的唯一方法，但存在收率低(收率小于90％)、污水量大的缺陷，目前一直未解决。

Molecular structures of fourteen 6-thioxanthine tautomers were calculated by the B3LYP/6-311G** method, both in gas and aqueous phases, with full geometry optimization. The Onsager solvate theory model was employed for aqueous solution calculations.

在密度泛函B3LYP/6-311G**水平下，对14种气相和水相中可能存在的6-硫代黄嘌呤异构体进行了几何构型的全自由度优化，并计算出它们的总能量、焓、熵、吉布斯自由能。

In stereoisomerism, substances with the same atoms are bonded in the same ways but differ in their three-dimensional configurations.

第二种类型是立体同分异构体，具有相同原子的物质以相同的键合方式结合，但它们的三维构型不同。

In stereoisomerism, substances with the same atoms are bonded in the same ways but differ in their three-dimensional configuration s.

第二种类型是立体同分异构体，具有相同原子的物质以相同的键合方式结合，但它们的三维构型不同。

Draw and give the stereochemical designation for the geometric isomers of 2,4-hetpadiene.

答：画出2，4-二庚烯的异构体的构型式

It can be. There are homogeneous cores in semiconductors made by companies such as Intel and Freescale, and there are heterogeneous cores in systems on chip, and sometimes there are both in SoCs.

其实这也不是不可能的，半导体中有许多同构内核由类似英特尔和飞思卡尔这样的公司制造，当然也有异构内核，有时两者都存在于SoCs中。

This one mode pays close attention to network credence foundation of the businessman very much.

这一模式非常关注商人的网络信用基础。

Cell morphology of bacterial ghost of Pasteurella multocida was observed by scanning electron microscopy and inactivation ratio was estimated by CFU analysi.

扫描电镜观察多杀性巴氏杆菌细菌幽灵和菌落形成单位评价遗传灭活率。