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In our study on the synthesis of glucosaminides we have employed 2,4-dinitropheuyl group (DNP) to protect the amino group of glucosamine, and foundthat DNP substitution brings forth an anomalous change in the optical rotation. By following Kent's procedure we obtained from 2-amino-2-deoxy-D-glucose hydrochloride (Ⅰ) N-DNP-2-amino-2-deoxy-D-glucose (Ⅱ). Its meltingpoint, 194°(200--202°, Kofler block), agrees with that reported by Meyer et al.(196±2°) and Morgan et al. (202-4°), but differs from that given...

In our study on the synthesis of glucosaminides we have employed 2,4-dinitropheuyl group (DNP) to protect the amino group of glucosamine, and foundthat DNP substitution brings forth an anomalous change in the optical rotation. By following Kent's procedure we obtained from 2-amino-2-deoxy-D-glucose hydrochloride (Ⅰ) N-DNP-2-amino-2-deoxy-D-glucose (Ⅱ). Its meltingpoint, 194°(200--202°, Kofler block), agrees with that reported by Meyer et al.(196±2°) and Morgan et al. (202-4°), but differs from that given by Kent(167-9°). The specific rotation values reported by all workers being practicallythe same([α]_D~(23)+50°; [α]_(5463)~(23)+68.7° in 80% ethanol). Acetylation of (Ⅱ) withacetic anhydride and pyridine gave a tetra-acetyl derivative (Ⅲ). Its meltingpoint (214-5°) and [α]_D~(20)(+12°, CHCl_3) also differed from those given by Kent(159-60°; [α]_D~(19)+73°, CHCl_3). (Ⅲ) was nearly quantitatively converted into1-bromo-3, 4, 6-tri-O-acetyl-N-DNP-2-amino-2-deoxy-α-D-glucose (Ⅴ) in usualway. Compound (Ⅴ) is identical with Stacey's bromo-compound (m. p. 162-4°[α]_D~(19)+46.0°, CHCl_3), obtained from another tetraacetyl-N-DNP-derivative (Ⅳ).Since (Ⅳ) was derived from the known 1, 3, 4, 6-tetra-O-acetyl-2-amino-2-deoxy-β-D-glucose (Ⅵ), and (Ⅲ) has also been prepared by us from 1, 3, 4, 6-tetra-O-acetyl-2-amino-2-deoxy-α-D-glucose hydrobromide (Ⅶ) of well establishedα-configuration, these two DNP-compounds (Ⅲ and Ⅳ) should form a pairof α- and β-anomers. Merely on the basis of Hudson's isorotation rule, it shouldbe predicted that (Ⅳ) wore tho α- and (Ⅲ) the β-anomer, which are contradictoryto their configurations as expected from the starting materials used. In order toconfirm the configuration of the C_(1)-atom of the compounds in question, otherpairs of DNP-derivatives of glncosamine, such as (Ⅷ) and (Ⅸ), (Ⅹ) and (Ⅺ),together with (Ⅻ) and (ⅩⅢ) were prepared according to the methods sketchedin Fig. 1. Melting points and specific rotations of these products are presentedin Tablo Ⅰ. Since (Ⅸ) and (Ⅺ) possess higher values of [α]_D than the correspondinganomers (Ⅷ and Ⅹ), (Ⅸ) and (Ⅺ) would be assigned as α-glucosaminides and(Ⅷ) mid (Ⅹ) as the β-anomers, if Hudson's isorotation rule were also applicableto N-DNP-glucosamine derivatives as usual. However, after removal of DNP-groupwith barium hydroxide, (Ⅺ) yielded the known methyl-β-D-glucosaminide (ⅩⅢ)and (Ⅹ), the corresponding α-D-glucosaminide (Ⅻ) (Ⅻ). The configurationsof (Ⅹ) and (Ⅺ) have been further confirmed by direct syntheses of these anomersfrom tho known methyl N-acetyl-α-and β-D-glucosamindes (ⅩⅠⅤ and ⅩⅤ). Con-sequently, (Ⅷ) and (Ⅹ) must be α-type, and (Ⅸ) and (Ⅺ) β-type. The N- DNP-substitution causes an anomalous change in the rotatory power, so that thesubstituted β-glucosaminides are considerably more dextro-rotatory than the cor-responding α-anomers. From Table Ⅰ, it is clear that the differences between the molecular rotations[M]_D of the anomeric pairs (Ⅲ) and (Ⅳ), (Ⅷ) and (Ⅸ) its well as (Ⅹ) and(Ⅺ), (i. e. 2A values) are all negative in sign, while the 2A values for anomericD-glucosamines, D-glucosamine hydrochlorides, pentaacetyl-D-glucosamines andmethyl-D-glucosaminides hydrochlorides are all positive. The 2B values of N-DNP-substituted products have the same sign and nearly the same magnitudeas those of the ordinary anomeric glucosamine derivatives. Thus DNP groupat C_(2)NH_2 has greater influence on the [M]_D of C_(1)-atom than on that of theremaining part of the molecule. This vicinaI effect of DNP-substitution on [M]_Dof the C_(1)-atom may be (i) due to change in polarity , (ii) due to increasein the number of conjugated double bonds (or shift in the absorption bands ofthe substituent, or (iii) due to steric interaction between vicinal substituensof the molecule.

在2-氨基-2-脱羟-D-葡萄糖的氮原子上引入2,4-二硝苯基后,其旋光性有显著的变化。自2-氨基-2-脱羟-D-葡萄糖(Ⅰ),我们获得一新的四乙酰-N-二硝苯基衍生物(Ⅲ), 该物经证明系属于吡喃糖α-型,但其旋光率比其β-端基差向异构体(Ⅳ)更向左旋,而与一般糖类α-与β-异构体之间的旋光率的关系不符。我们再观察N-二硝苯-2-胺基-2-脱羟-D-葡萄糖甲甙及其乙酰衍生物的α-与β-异构体的旋光率,也有相同的反常现象。 Hundson同旋律不完全适用于以上的N-二硝苯-D-胺基葡萄糖及其衍生物的原因可能由于C_(2)原子上N-二硝苯基对邻位C_(1)旋光性的影响所致。

A brief study on the effect of addition of cumene hydroperoxide (II, CHP, in text) without or with simultaneous addition of an alkaline additive (sodium carbonate or calcium oxide) on the reduction of the induction period in the autoxidation of cumene (I) showed that the heterogeniety inherent in the latter systems resulted in poor reproducibility. Sodiumsalt of cumene hydroperoxide (III) was introduced as an oilsoluble system in which the initiator and the alkaline additive are in combination. Experiments...

A brief study on the effect of addition of cumene hydroperoxide (II, CHP, in text) without or with simultaneous addition of an alkaline additive (sodium carbonate or calcium oxide) on the reduction of the induction period in the autoxidation of cumene (I) showed that the heterogeniety inherent in the latter systems resulted in poor reproducibility. Sodiumsalt of cumene hydroperoxide (III) was introduced as an oilsoluble system in which the initiator and the alkaline additive are in combination. Experiments with various amounts of III at 110° 120°and 130°that the induction period and the autocatalysis were either completely or practically eliminated. The reproducibility of the experiments accompanying the use of III was extremely good. The rate of accumulation of II was 16±0.7% (wt.)/hr. at. 130° at 120° the rate was 8.7%/hr. except when the amount of III was 3.33% (7.3%/hr.); at 110° the rate varies more pronouncedly with the amount of III (3.0-5.0%/hr.).

初步观察了在异丙苯(Ⅰ)自动氧化为异丙苯过氧化氢(Ⅱ)中仅加入异丙苯过氧化氢作为引发剂及同时加入硷性添加剂碳酸钠或氧化钙对缩短或消除诱导期及对Ⅱ累积速率的影响。由于在上述体系中固体硷性剂的悬浮性使反应不易重复,引用了油溶性的异丙苯过氧化氢钠盐(Ⅲ)作为引发剂-硷性剂二者合而为一的体系,用不同加入量,在110°、120°及130℃进行试验,发现诱导期及自动催化期完全或基本上消除,反应极易重复。Ⅱ的累积较在前述情况下的为佳。 在用密闭系统吸氧法进一步研究有Ⅲ存在下的诱导期消失情况时,发现在氧化开始最初几分钟内有快速吸氧现象。认为这是硷与Ⅱ作用引发了氧化链。仅仅加入氢氧化钠也同样产生起始快速吸氧现象,这应是Ⅰ中存在的微量Ⅱ所引起的。在使用Ⅲ情况下的氧化效率求出为92—97%。 迸行了在110°的Ⅰ自动氧化中加入硬酯酸钴的催化效应的研究,消除了诱导期。虽然起始累积速率提高了,但是由于钴盐对Ⅱ的分解,Ⅱ的累积程度不高。同时加入少量Ⅱ并不更加提高起始的累积速率,显然Ⅰ中已有的微量Ⅱ已足够担负与钴盐作用引起反应链。同时加入钴盐和Ⅲ大大提高了Ⅱ的累积速率,相当于仅加Ⅱ或Ⅲ时在130°的累积速率。累积程度亦可达40%。可供...

初步观察了在异丙苯(Ⅰ)自动氧化为异丙苯过氧化氢(Ⅱ)中仅加入异丙苯过氧化氢作为引发剂及同时加入硷性添加剂碳酸钠或氧化钙对缩短或消除诱导期及对Ⅱ累积速率的影响。由于在上述体系中固体硷性剂的悬浮性使反应不易重复,引用了油溶性的异丙苯过氧化氢钠盐(Ⅲ)作为引发剂-硷性剂二者合而为一的体系,用不同加入量,在110°、120°及130℃进行试验,发现诱导期及自动催化期完全或基本上消除,反应极易重复。Ⅱ的累积较在前述情况下的为佳。 在用密闭系统吸氧法进一步研究有Ⅲ存在下的诱导期消失情况时,发现在氧化开始最初几分钟内有快速吸氧现象。认为这是硷与Ⅱ作用引发了氧化链。仅仅加入氢氧化钠也同样产生起始快速吸氧现象,这应是Ⅰ中存在的微量Ⅱ所引起的。在使用Ⅲ情况下的氧化效率求出为92—97%。 迸行了在110°的Ⅰ自动氧化中加入硬酯酸钴的催化效应的研究,消除了诱导期。虽然起始累积速率提高了,但是由于钴盐对Ⅱ的分解,Ⅱ的累积程度不高。同时加入少量Ⅱ并不更加提高起始的累积速率,显然Ⅰ中已有的微量Ⅱ已足够担负与钴盐作用引起反应链。同时加入钴盐和Ⅲ大大提高了Ⅱ的累积速率,相当于仅加Ⅱ或Ⅲ时在130°的累积速率。累积程度亦可达40%。可供工业上考虑采用。

Much experimental studies on the polyesterification reactions between dibasic acids and glycols have been reported by various authors,among them Menshytkir,Dostal and Raff,Flory,Rafikov and Korshak,Davies,Colonge and Stuchlik,and others,but quite diversed results were obtained.According to Flory,polyesterification in the absence of a foreign acid,owing to catalytic effect of the dibasic acid molecule,is a third-order reaction.Other authors pointed out that,polyesterification should be a bimolecular reaction...

Much experimental studies on the polyesterification reactions between dibasic acids and glycols have been reported by various authors,among them Menshytkir,Dostal and Raff,Flory,Rafikov and Korshak,Davies,Colonge and Stuchlik,and others,but quite diversed results were obtained.According to Flory,polyesterification in the absence of a foreign acid,owing to catalytic effect of the dibasic acid molecule,is a third-order reaction.Other authors pointed out that,polyesterification should be a bimolecular reaction of second-order,or second-order in the early stage and third-order in the later stage of the reac- tion.In this work,we attempted to show that,polyesterification between dibasic acid and glycol is as well as esterification between monoacid and monoalcohol,provoked by the catalysis of hydrogen-ion.When the dibasic acid and the glycol react in equi-molar quantity ratio in the absence of a foreign acid,the hydrogen-ions come from the ionization of the dibasic acid itself,and in consequence the concentration of hydrogen-ion is proportional to the square root of the concentration of the dibasic acid,polyesterification is a 2~1/_2-order reaction.On the other hand,in the presence of a foreign acid,the order of reacton varied continuously from one extreme ease of 2~1/_2-order to another extreme case of second order according to whether the concentration of hydrogen ion derived from the foreign acid or the dibasic acid may be neglected.All our experimental results of polyesterification reactions either between sebacic acid and ethylene glycol,sebacic acid and diethylene glycol,adipic acid and hexamethylene glycol,and sebacic acid and hexamethylene glycol in the absence of foreign acid at different temperatures,or between adipic acid and ethylene glycol in the presence 0.41,0.82,1.23,2.05,4.10 and 12.30.10~(-3) mole of sulfuric acid per kilogram as catalyst at 140℃,are in good agreement with this proposed mechanism.Data of other authors were re-examined on the basis of our proposed mechanism of hydrogen ion catalysis in esterification and were all found to conform to the 2~1/_2-order relationship.Thus,the views by earlier workers that polyesterification is catalyzed by the dibasic acid molecule itself or that it is a simple second-order reaction,or a second-order in the early stage and a third-order in the later stage of the reaction,all are refuted and the long disputed question of the order of polyesterification is assumed to be clarified.

聚酯反应象单元酸与单元醇的酯化反应一样,都是氢离子催化机构。这种机构与现在公认的聚酯反应的氢离子催化机构的区别在于氢离子的来源和氢离子参与反应的详细历程,肯定了氢离子不仅由外酸供给,而且也可由二元酸本身供给。另外,二元酸与二元醇均可作为氢离子的载体。聚酯反应的动力学方程与二元酸与二元醇的起始克分子比有密切关系,应由前篇(3)式表示。当酸与醇以等克分子比起反应,又无外酸存在时,聚酯反应是2(1/2)级反应;若有外酸作催化剂时,当外酸的量加得适当多,由二元酸本身供给的氢离子的贡献可以忽略时,是二级反应,与以往结论相一致:当外酸的量加得少,必须考虑氢离子的同离子效应,它就不再是简单的二级反应,当酸与醇以不等克分子比起反应我们的实验结果亦与理论一致。

 
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