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   cotton effect 的翻译结果: 查询用时:0.173秒
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cotton effect
相关语句
  cotton效应
     Finally, according to the negative Cotton effect of n→π CD band of α,β-unsaturated δ-lactone in 252 nm, the absolute configuration was assigned.
     进一步由α、β-不饱和δ内酯在圆二色散中n→π~*区Cotton效应推出了3的绝对构型。
短句来源
     Furthermore Cotton effect and Cotton split of CD spectra of these chiral compounds were explained by the exciton interaction theory.
     另外,用激子偶合理论解释了此类手性化合物圆二色谱的Cotton效应和Cotton分裂.
短句来源
     This paper reports the CD and UV spectra of the β- cdx inclusions of α- naphthylamine, β- naphthylamine, α- naphthylacetic acid and according to KAJTAR sector rule the Cotton effect and g factor give the orientation of guest molecules in β- cdx, correlates the CD spectra the orientation of guest molecules in β- cdx and the quantum calculating for the electric moment of transition.
     本文报道了β-环糊精分别包结α-萘胺、β-萘胺、α-萘乙酸的圆二色谱及紫外吸收光谱,并利用KAJTAR扇形规则,根据所测得的Cotton效应符号和各向异性因子确定了客体分子在环糊精空腔中的取向。
短句来源
     Studied the influence of temperature, pH, Ca2+, boron and congo red on circular dichroism of konjac glucomannan,the results showed that it brought a new cotton effect when in high pH, the rest mainly brought out the changes on absorptionintensity in different extent.
     研究了温度、pH、钙离子、硼和刚果红等对魔芋葡甘聚糖溶液园二色性的影响,结果显示在高pH条件下产生新的cotton效应,其余均表现为不同程度吸收强度的变化。
短句来源
     When chloroform was used as solvent and the concentration was 65wt%,the handedness of the two helicoidal structures was left handed (positive Cotton effect),but when dioxane or THF was used with the same concentration,a reversed handedness was observed.
     以氯仿为溶剂 (固定浓度为 6 5 % )时两种螺旋结构均为左旋 (正Cotton效应 ) ,但二氧六环和四氢呋喃为溶剂时均变为右旋 (负Cotton效应 ) .
短句来源
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  “cotton effect”译为未确定词的双语例句
     Aqueos solution of SPG-l-P had an apparently positive Cotton effect at 20 C.
     SPG-1-P在常温中性水溶液中有明显的正科顿吸收(Cotton effect)。
短句来源
     290 nm and 305 nm respectively, with a weaker amplitude for the C_6-carbonyl. The Cotton effect extremum of the C_6-carbonyl can be eliminated upon acidification.
     对海替辛(Hetisine)型分子中的N—C_6键断裂作了探索发现N—氯甲基化,碱热解是简便易行的方法(甲基化物很稳定,不能断裂)。
短句来源
     Aqueous solution of SPG-l-P had an apparently positive Cotton effect at 20 C .
     SPG-1-P在常温中性水溶液中有明显的正科顿吸收(Cotton Effect)。
短句来源
     The results obtained showed that the CD spectra of the QBBI alkaloids were similar to those of their original tertiary bisbenzylisoquinoline (BBI) alkaloids, with the difference that the negative Cotton effect (CE) at 246 nm in the CD spectra of the BBI disappeared in the CD spectra of the QBBI. There were only slight changes in the CD spectra of the QBBI on protonation.
     为探讨QBBI生物碱的CD谱,本文对从粉防已块根中分离得到并经结构鉴定的QBBI生物碱的CD谱进行了初步的研究。 结果表明,QBBI生物碱的CD谱与其相应的BBI生物碱的CD谱大致相似,但亦存在着差异。
短句来源
     In the nean time,the inducement to McAb 3B6 from the porphyrin resulted in a large induced Cotton effect(ICD). Quantitative analyses of the combination between porhpyrin and antibody by ICD showed that not only 1∶1 combination occurred in excess of antibody over porphyrin.
     用紫外(UV)可见和圆二色谱(CD)分析四(4-三甲胺苯)卟啉同抗体的结合,表明(四(4-三甲胺苯)卟啉与单抗体,既有1∶1结合又有2∶1结合.
短句来源
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  相似匹配句对
     Effect of K-fertilizer on Cotton
     棉花的钾肥效应试验
短句来源
     Study on the effect of cotton bollworm metabolize with B. t.
     苏云金杆菌对棉铃虫代谢影响研究
短句来源
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  cotton effect
The correlation of the Cotton effect sign of the n→π*-transition with the chirality of the cage structure and the absolute configuration for the series of 1,4-dialkyldilactones of type1 has been suggested.
      
The Cotton effect sign of the n→π*-transition of the lactone chromophore in enantiomers1 is determined by the contribution of the uncompensated bonds of the δ-dilactone ring, but not by that of the γ-monolactone ring of1.
      
The dependence of the sign of Cotton effect in the region of 300-350 nm upon the absolute configuration of chiral centers remote from the Cp-ring has been demonstrated.
      
Chlorpromazine, which contains both of these substituents reversed the sign of the induced Cotton effect with the highest intensity.
      
The sign of the induced Cotton effect of dicumarol bound to AGP was reversibly changed with the introduction of the propyldimethylamine substituent at position 10 or chloride group at position 2 of the phenothiazine molecule.
      
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Chuanliansu (Ⅰ), C_(30)H_(38)O_(11), isolated from the bark of Melia toosendan et Z., is an active anthelmintic against ascaris.The NMR spectrum of chuanliansu (Ⅰ) showed three quarternary C-methyl groups and two acetoxyl groups.Acetylation of I with acetic anhydride and pyridine under forcing conditions yielded acetylchuanliansu (Ⅱ), C_(36)H_(44)O_(14), with a molecular weight of 700 as shown by mass spectrometry.Chuanliansu is a triterpenoid derivative containing a β-substituted furan ring.This is supported...

Chuanliansu (Ⅰ), C_(30)H_(38)O_(11), isolated from the bark of Melia toosendan et Z., is an active anthelmintic against ascaris.The NMR spectrum of chuanliansu (Ⅰ) showed three quarternary C-methyl groups and two acetoxyl groups.Acetylation of I with acetic anhydride and pyridine under forcing conditions yielded acetylchuanliansu (Ⅱ), C_(36)H_(44)O_(14), with a molecular weight of 700 as shown by mass spectrometry.Chuanliansu is a triterpenoid derivative containing a β-substituted furan ring.This is supported by the presence of oharaeteristic infrared bands at 3.25, 6.63 and 11.4μ and of NMR peaks at δ 6.15, 7.35 and 7.55.Hydrogenation of chuanliansu afforded tetrahydrochuanliansu (Ⅳ), C_(30)H_(42)O_(11),resulting in the saturation of the furan ring.Ozonolysis of acetylchuanliansu (Ⅱ) caused the cleavage of the furan ring to give the acid (Ⅶ), C_(33)H_(42)O_(15), with a pK_a value, expected for saturated carboxylic acids bearing no oxygen on the α-carbon.Reaction of Chuanliansu and acetylchuanliansu with thiocyanic acid gave Ⅷ-1 and Ⅷ-2, respectively, each with one molecule of water less than that calculated for a simple addition product (as shown by elemental analyses). This reveals the presence of a 1, 2-epoxide, and the stereochemistry of ring D may be expressed as A.The ORD curves of acetylchuanliansu (Ⅱ) and the acid (Ⅶ) obtained on ozonolysis both showed simple negative Cotton effect. The amplitude of the latter compound (Ⅶ) is markedly lower than that of the former (Ⅱ). According to the octant rule, we may place the koto grouping in ring C. The furan ring in the thiocyanic adducts (Ⅷ-1 and Ⅷ-2) was conjugated with the 13 (17) double bond as substantiated by their ultraviolet maxima at 234 nm. If the carbonyl group were at position 12, the extended conjugated system would be expected to show an absorption maximum at 314 nm. Thus we consider, by elimination, that the carbonyl group is situated at position 11. In furanoid triterpenes there are usually five C-methyl groups, but chuanliansu and its derivatives such as ⅩⅥ all revealed only three C-methyl groups in their NMR spectra. Therefore two hydroxymethyl groups should be present. Chuanliansu(Ⅰ) itself under mild alkaline conditions releases formaldehyde. This indicates that one hydroxymethyl group (—CH_2OH) is located at position 9, the α-position of the 11-keto group. This hydroxymethyl group should be of β-configuration on biogeneticgrounds (migrating from C-10), reminiscent of cucurbitacin.Treatment of deacetylchuanliansu (Ⅲ) with bismuth trioxide gave a black precipitate, the response being quicker than that of benzoin. But no reaction was observed with chuanliansu itself. Furthermore, oxidation of deacetylchuanliansu with chromic trioxide in pyridine gave an α-diketone (Ⅻ) as opposed to chuanliansu itself. Therefore an acetoxy group should be placed on C-12 of chuanliansu(Ⅰ).Most of the oxidation products of Ⅰ and Ⅱ were α, β-unsaturated ketones. Tetrahydrochuanliansu (Ⅳ) had an ultraviolet end absorption, expected of a trisubstituted double bond. These facts led us to suggest that one double bond and one hydroxyl group were in allylic relationship and located in ring B.Chromic trioxide oxidized deacetylchuanliansu to an α, β-unsaturated ketone which we now formulate as Ⅻ. This ketone rapidly absorbed approximately one mole of oxygen in dilute alkali at room temperature, presumably to furnish the fully conjugated dienedione(G). Since the α, β-unsaturated ketones obtained from Ⅰ did not absorb oxygen under the same conditions, an acetoxy group may be present at position 2 in ring A.When Ⅰ was fused with alkali, acetone was obtained. Therefore an ether linkage may be placed between C-3 and C-4. These results finally led to the proposal of formula Ⅰ as the structure of chuanliansu.

川楝素是从川楝树皮中提出的驱蛔活性成分,分子式为C_(30)H_(38)O_(11)。含有二个乙酰氧基;三个游离羟基,其中一个与双键有烯丙醇关系;一个羰基处于乙酰氧基的邻位;还有β-单取代呋喃环和1,2环氧基等基团。为一呋喃三萜。通过化学反应及光谱分析,初步确定它的化学结构及其立体构型如Ⅰ式所示。

In this paper, the ORD and sector projection of 6 synthetic γ-lactone intermediates of Qinghaosu(Arteannuin) are reported. By-using ketone octant rule, lactone chirality rule and lactone sector rule, the predicted cotton effects of these compounds coincided with the result of determination and so the absolute configurations were assigned.

本文报道了6个青蒿素合成中间体—γ内酯化合物—的旋光谱和扇形图。应用羰基的八区律、内酯的手性规则和内酯的扇形规则,所预测的这些化合物的cotton效应与实测结果一致,从而指定了它们的绝对构型。

Xian-Ye-Xuan-Fu-Hua, the flowers of Inula linariaefolia Turcz (Compositae),is a commonly known Chinese medicinal herb and used as expectorant as well as for the treatment of some malignant tumors. The chemical investigation of its active principles by our early work in 1964 resulted in the isolation of a new sesquiterpene lactone(m.p.190~192℃, [α]_D-24°in CHCl_3), which possesses significant inhibitory action against Hela cells and fungi in vitro. Besides, it also shows some expectorant activity in preliminary...

Xian-Ye-Xuan-Fu-Hua, the flowers of Inula linariaefolia Turcz (Compositae),is a commonly known Chinese medicinal herb and used as expectorant as well as for the treatment of some malignant tumors. The chemical investigation of its active principles by our early work in 1964 resulted in the isolation of a new sesquiterpene lactone(m.p.190~192℃, [α]_D-24°in CHCl_3), which possesses significant inhibitory action against Hela cells and fungi in vitro. Besides, it also shows some expectorant activity in preliminary pharmacological tests. Analyses of the spectral data (IR, UV, ~1H NMR, ~(13)C NMR, MS) and our early results of chemical reactions suggested that the compound is the same as britanin 1(m.p.192~194℃, [a]_D-26°in CHC1_3)studied by Chugunov in 1971. However its stereochemistry remained unsolved. On careful examination of the 360 MHz ~1H NMR data (in CDCl_3 and in C_6D_6)and the Cotton effects of ORD spectra of its saturated lactone and cyclopentanone derivatives, we considered that britanin must be ambros-11(13)-en-2β, 4β, 6α, 8α-tetraol-12-oic-(12,8) -lactone, 2, 6-diacetate (7). Since the large values for J_(6,7,)J_(7,8,) J_(8,9) J_(9,10) and J_(1,10) indicate the existence of successive a-a trans coupling in all vicinal protons from C_6 to C_1, the conformation of the cycloheptane ring must be in the chair form. The other constituent isolated from the same plant has been identified as taraxasteryl palmitate.

1964年我们从菊科植物线叶旋复花(Inula linariaefolia Turcz)中提得一个新的倍半萜内酯,药理试验表明具有明显的抗肿瘤Hela细胞、祛痰、抑制霉菌等活性。通过波谱分析并结合早期的化学工作,现已确定它即为同属植物I.britannica中分得的britanin,但britanin的立体结构尚未见报道。根据~1HNMR以及其衍生物的旋光谱的研究,推定britanin的立体结构应为ambros ll(13)-en-2β,4β,6α,8α-tetraol-12-oic-(12,8)-lactone,26-aiacetate(7),分子中的七元环则以椅式构象存在。此外,还鉴定了同一植物中分得的另成分为蒲公英醇软脂酸酯(taraxasteryl palmitate)。

 
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