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排序方式: 共有365条查询结果,搜索用时 31 毫秒
1.
Archana Devi 《European Polymer Journal》2007,43(6):2422-2432
Cardanol-based novolac-type phenolic resins were synthesized with different mole ratios of cardanol-to-formaldehyde, viz., 1:0.6, 1:0.7, and 1:0.8. These novolac resins were epoxidized with molar excess of epichlorohydrin at 120 °C in basic medium. The epoxidized novolac resins were, separately, blended with different weight ratios of carboxyl-terminated polybutadiene liquid rubber ranging between 0-25 wt% with an interval of 5 wt%. All the blends were cured at 150 °C with 40 wt% polyamide. The formation of various products during the curing of blend samples has been studied by Fourier-transform infra-red spectroscopic analysis. The tensile strength and elongation-at-break of the cured samples increased up to 15 wt% in the blend and decreased thereafter. This blend sample was also found to be most thermally stable system. The blend morphology, studied by scanning electron microscopy analysis, was finally correlated with the structural and property changes in the blends. 相似文献
2.
Vanadium(IV) forms colored chelates with Erio T and Solo 6 BN (λmax 570 and 580 nm, respectively) at pH 3.8. The composition MR2 of the chelates investigated was established by continuous variation, mole ratio, slope ratio and straight-line methods spectrophotometrically. For photometric determination of V(IV) with these reagents Sandell's sensitivity, Beer's law range, Ringbom optimum range were also determined. Bjerrum and Calvin potentiometric titration technique was employed to determine the stepwise formation constants of each system. For V(IV)-Erio T system values of log K1 = 14.4, log K2 = 10.9 and for V(IV)-Solo 6 BN system log K1 = 16.1, log K2 = 11.8 were obtained. 相似文献
3.
Vinod K. Tiwari Archana Singh Hakkim A. Hussain Bhuwan B. Mishra Vyasji Tripathi 《Monatshefte für Chemie / Chemical Monthly》2007,138(7):653-658
Summary. A convenient and high yielding method for the synthesis of diverse dithiocarbamates having various substituents including
alkyl, aryl, heteroaryl, and alkylaryl at the thiol chain or at the amine chain or at both thiol and amine chains were developed
by the one-pot reaction of mercaptans, amines, and bis(benzotriazolyl)methanethione in presence of amidine base under mild
reaction conditions. 相似文献
4.
Different molar reactions of Fe(OPr1)3, and FeCl3 with benzothiazolines having an NSH donor system. derived by the condensation ofo-aminothiophenol with heterocyclic aldehydes. viz. pyridine-2-aldehyde. furfuraldehyde and thiophene-2-aldehyde. lead to the
formation of [Fe.Pr1(NS)2]2, [Fc(NS)3] and [Fe(NS)2Cl| type of complexes. The resulting derivatives have been characterized by elemental analysis, conductivity measurements,
molecular weight determinations and magnetic studies. IR, electronic, M?ssbauer and ESR spectral data have been used to deduce
the structures of the resulting derivatives. 相似文献
5.
Kyle Clagg Sara Hold Archana Kumar Stefan G. Koenig Remy Angelaud 《Tetrahedron letters》2019,60(1):5-7
The direct application of Knochel-Hauser derivative arylmagnesium halides in Kumada-Corriu couplings is described. By utilizing the in situ-generated Grignard reagents, the transmetalation with stoichiometric zinc salts to known Negishi coupling conditions is avoided, thereby streamlining the transformation. Several aromatic hetereocycles participate in the deprotonation and couple with a variety of phenyl iodides and bromides in isolated yields up to 81%. The parent system is demonstrated on 6?g scale with 79% yield, and monitored via ReactIR to show the stability of the Grignard and progression of the deprotonation/CC coupling reaction. 相似文献
6.
Pharmacokinetic studies of a novel trioxane antimalarial (99/411) in rats and monkeys using LC–MS/MS 下载免费PDF全文
The pharmacokinetic profile of 99/411, a novel anti‐malarial drug, was established in rats (12 mg/kg of body weight) and monkeys (20 mg/kg of body weight). Following oral administration, the presence of 99/411 was rapidly determined in rat plasma, tissues, urine, feces and monkey plasma using a validated LC–MS/MS method. The tissue distribution studies in rats indicated that the drug was partially distributed in all major tissues and plasma, and peak concentration levels were achieved within 0.5–4 h. Area under the curve in different rat tissues and plasma was found in order of blood > lung > intestine > heart > muscle > brain > kidney > spleen > liver. The total recoveries (within 86 h) of 99/411 were <0.0017% and <0.08% in urine and feces, respectively. The peak plasma concentration was 3499 ng/mL in rats after ~2 h of oral administration and 697–767 ng/mL in monkeys after ~6 h of oral administration. No plasma accumulation was observed in both male and female monkeys, even after multiple dosing. The preclinical pharmacokinetic profile and tissue distribution data are expected to assist in future clinical explorations of 99/411 as a promising anti‐malarial agent. 相似文献
7.
Copper thin films were prepared by sono-electrodeposition method at different acid concentrations in the electrolyte. A potential of ?450 mV (100 mV negative than the Nernst potential) was selected for the deposition procedure for all the conditions. The thickness of films was found to be in the range of 100–600 nm. Electrochemical analysis was performed by chronoamperometry. Films were characterized by XRD, SEM, AFM, and study of the mechanical properties was done by nanoindentation. 相似文献
8.
9.
A new and efficient synthesis has been developed for the title indolocarbazole which has been indicated by a recent computer-aided study to be a potent ligand for the receptor for the naturally occurring carcinogen, TCDD. 相似文献
10.
Journal of Solid State Electrochemistry - Nanostructured MnO2 films were prepared via cathodic electrodeposition under potentiostatic condition. X-ray diffraction (XRD) analyses reveal that the... 相似文献