查询词典 sterically

The facts indicate that apart from the asymmetric induction of chiral diamine backbone,sterically hindered substitute groups on the aromatic rings,and the presence of sp~3-hydridized amino donors and its N,N\'-disubstituted groups in chiral SalanCrX complexes all play important roles in controlling polymer stereochemistry and enantioselectivity.

研究发现除了手性二胺骨架的不对称诱导作用，苯环上的大位阻取代基、N，N\'-二取代基的位阻作用以及N原子上sp~3杂化的供电子效应都对调控聚合物的区域和对映体选择性有很大作用。

Followed two-compartment model, the biological half-life of chTNT-3-SL and (chTNT-3/B + SAv-SL) in rats was longer than that of free doxorubicin but shorter than sterically stabilized liposomes.

结果表明，两种主动靶向脂质体给药系统与固定Raji细胞的结合量均显著高于阴性对照组(P＜0.001)。

As for the ester exchange reaction on phosphorus, it was found that N-phosphoryl histidine the fastest one among all of the N-phosphoryl aminoacids. The results studied by MNDO method indicate that due to theparticipation of imidazole group, the formation of hexa-coordinatephosphorus intermediate made the iso-propoxyl which is opposite toimidazole group more active than the other ones and much easier to leave.When iso-propoxyl left, a new penta-coordinate phosphorus intermediate wasformed, and it is sterically favorable to be attacked by an alcohol from theopposite direction of imidazole.

对于磷上酯交换反应，实验中发现N-磷酰组氨酸反应速度明显高于其它N-磷酰氨基酸，理论研究表明，侧键咪唑基参与下六配位磷中间体形成后，位于咪唑基对面的异丙氧基反应活性大大提高，即从咪唑基的对面位置发生异丙氧基的离去和另一分子醇的进攻，在能量上和空间上都是有利的。N-磷酰丝氨酸的磷上酯交换反应有着类似的特点。

To further testify the high efficiency of these new reagents in the synthesis of sterically hindered peptides, we successfully synthesized the extensively -N-methylated peptide moiety of the antineoplastic and lipophilic depsipeptide Dolastatin 15 using reagent BEP and FEP. We also synthesized the highly hindered tetrapeptide segment of Cyclosporin A using reagent BEMT and BEP, respectively.

为进一步检验这类吡啶正离子型缩合剂在有空间位阻的多肽合成中的性能，我们以BEP和FEP为缩合剂，成功地合成了具有抗肿瘤活性的亲脂性酯肽Dolastatin 15分子中高N-烷基化的肽链部分；分别以BEMT和BEP为缩合剂合成了生物活性肽Cyclosporin A中空间位阻最大的四肽片断。

But we don't care about Battlegrounds.

但我们并不在乎沙场中的显露。

Ah! don't mention it, the butcher's shop is a horror.

啊！不用提了。提到肉，真是糟透了。