查询词典 sterically

Magnesium methylate can be prepared by reacting magnesium with dry methanol; Primary alcoholates can be prepared by alcoholysis; the sterically demanding substituted magnesium alcoholates can be prepared by ester exchange or from dialkylmagnesiums.

综上所述，几乎所有的醇镁化合物都可以通过这三种方法进行制备：甲醇镁通过直接合成法制备；伯醇镁通过醇解法制备；仲醇镁或叔醇镁通过酯交换或烷基镁法制备。

The transition metal complex has a pentagon ring structure having an amido group connected by a phenylene bridge in which a stable bond is formed in the vicinity of a metal site, and thus, a sterically hindered monomer can easily approach the transition metal complex.

该过渡金属配合物具有由亚苯基桥连接的酰胺基的五边环结构，其中在金属位置附近形成稳定键，因此位阻单体可容易地接近过渡金属配合物。

AVI may be protein matrix and it possesses neither a membrane boundary nor an internal structure,its formation is the result of the anthocyanins transported into the vacuole bind with a protein matrix. In vacuole, AVI is irregular and jelly-like in shape. In AVIs, the attachment of anthocyanins to the matrix protein is likely to be via H-bonds to a sterically restricted site. AVI is suggested to act as vacuolar anthocyanin "trap", preferentially for anthocyanidin 3, 5-diglycosides or acylted anthocyanins. The emergence of AVI can enhance color intensity and results in the "blueness" of color in the vacuole.

花色苷液泡包涵体可能具备蛋白质基质，既无膜包裹又无内部结构，其形成是转运进液泡的花色苷与蛋白质基质结合的结果；液泡里的花色苷液泡包涵体形状不规则，象果冻；在花色苷液泡包涵体中，花色苷可能通过氢键连接于蛋白质基质的一个有限空间位点；花色苷液泡包涵体被认为是液泡中花色苷的&陷阱&，优先摄取花色素3，5-二糖苷或酰化的花色苷；花色苷液泡包涵体的存在可增加液泡色彩的强度并导致&蓝化&。

Different from conventional fabrication of cathode powder, non-chelating polymer polvinyl alcohol serves to sterically entrap the metal cationa in a manner thewey which facilitates the formation of an atomistically homogeneous precursor material. And, calcining the solid precursor material to form a mixed metal oxide material, that is perovskite structured powder La0.5Sr0.2Co0.5Fe0.5O3.

该方法与传统方法不同，采用非螯合聚合物－聚乙烯醇(PVA， Polvinyl alcohol)作为阳离子的载体，形成含有La(上标 3+)，Sr(上标 2+)，Co(上标2+)，Fe(上标 3+) 4种金属阳离子和非螯合聚合物的均匀溶胶，干燥生成固体凝胶状前驱体。

Pd(PPh3)4 was more reactive for boronic acids with sterically hindering F atom, and the coupling reactions gave good yields of 90% and 91% without any self-coupling by-product.

Pd(PPh3)4对于含有位阻F原子苯硼酸的偶联反应很具有活性，且没有自偶联产生，产率可达90%及91%。

The synthesis of sterically hindered peptides containing N-alkylated or 〓disubstituted amino acid residues is being a challenge, which results in difficultcondensation using the usual DCC/HOBt or HOBt-derived coupling reagents.

多肽合成的一个主要难题是富含N-烷基化氨基酸或C〓二烷基化氨基酸的肽链的合成，采用BOP或HBTU等常规缩合剂往往不能得到令人满意的结果。

Result shows that the sulfur compounds in the diesel can react with iodomethane easily at room temperature, the most of sulfur compound derived into methylsulfonium salts; the homologue of benzothiophene get the higher conversion ratio and react selectivity than the homologue of dibenzothiophene. It is found that primarily sterically hindered alkylated DBT, for example, 4-or 4-, 6-DBT, is recalcitrant to be methylated.

结果表明：柴油中硫化物在室温条件下容易与碘甲烷发生甲基化反应，大部分硫化物转化为锍盐，总转化率超过80%，苯并噻吩类比二苯并噻吩类更易发生甲基衍生化反应，转化率也相应较高。

However, the reaction speed decreased and more solid green product isolated due to the sterically hindering of ester group.

只是由于酯基的空间位阻效应而使反应速度变慢，析出的固体绿色化合物更多。

B3The sterically allowed values of φandψare visualized in a Ramachandran plot.

在莱幔图谱上可看见φ与ψ的立体允许值。

Work 工作:(1) feasible process development for high-pure tetraalkyphosphonium salt as catalysts for polymerizations, potential sale 2-4 million us$;(2) simple and feasible preparation process for phosphonium salt as ionic liquids, biocides and phase transfer catalysts;(3) new and industrially feasible processes for highly sterically hindered alkylphosphines as catalyst ligands, these include tricyclohexyl-phosphine, phosphorinanes and dsmphos2,3- bis(9-phosphabicyclononylbutane;(4) sterically hindered dialkylphosphinic acid as new generation of co/ni extractant;(5) alkylphosphonium wittig reagents and the wittig reactions with them;(6) exploration of the application of borane chemistry in the synthesis of highly sterocally hindered organophosphines;(7) customer preparation of samples of a variety of organophosphorus compounds for customers all over the world.

用作高分子聚合反应催化剂的高纯度四烷基瞵盐的实用生产流程。产品销售前景 2-4 百万美元；(2)用作离子化液体，杀菌剂和相转移催化剂的烷基瞵盐的简单实用合成方法；(3)高位阻烷基磷化氢催化剂配体的工业实用合成路线的研究，这包括，三环己烷基磷， phosphorinanes 和 dsmphos 2，3-bis(9-phosphabicyclononylbutane ；(4)高位阻二烷基膦酸金属萃取剂的工业实用合成路线的研究；(5)烷基膦 wittig 反应试剂的研究；(6)硼化学在高位阻烷基磷化氢合成中的应用；(7)为世界各地提供顾客合成服务。

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。