排序方式: 共有37条查询结果,搜索用时 15 毫秒
1.
Two novel bidentate Schiff base ligands, 2-(2-hydroxy-3,5-dichloro/diboromo) benzaldehyde-[4-(3-methyl-3-mesitylcyclobutyl)-1,3-thiazol-2-yl]hydrazone,
L1H, L2H and their transition metal complexes are reported. The new ligands and their complexes have been characterized by elemental
analyses, ΛM, infrared, u.v.–vis, 1H- and 13C-n.m.r. spectroscopy, and magnetic susceptibility measurements. The thermal properties of all complexes have been investigated
by TG technique. The complexes contain two monoanionic, bidentate NO ligands. It was found that all the complexes are mononuclear.
Antimicrobial activities of the ligands and their complexes have been tested against five different microorganisms, and some
of the complexes were found to be active against some of the microorganisms studied. 相似文献
2.
Leyla Bitiş Sevda Süzgeç Ulaş Sözer Hasan Özçelik Josef Zapp Alexandra K. Kiemer Filiz Meriçli Ali H. Meriçli 《Helvetica chimica acta》2007,90(11):2217-2221
From the aerial parts of Delphinium buschianum Grossh ., collected in Turkey, a new diterpenoid alkaloid 1 , named budelphine, was isolated along with the known diterpenoid alkaloids karakoline ( 2 ), 18‐hydroxy‐14‐O‐methylgadesine ( 3 ), delsoline ( 4 ), lapaconidine ( 5 ), columbianine ( 6 ), 14‐benzoylneoline ( 7 ), and hetisine ( 9 ). The structure of 1 was established on the basis of 1H‐, 13C‐, DEPT, 1H,1H‐COSY, NOESY, HSQC, and HMBC NMR studies. 相似文献
3.
Positivity - In this paper we investigate the distance of convergence in measure whenever the measure is not $$\sigma $$ -finite and identify the topological coreflection of this approach structure... 相似文献
4.
Yıldırım Işıl Aktaş Aydın Celepci Duygu Barut Kırbağ Sevda Kutlu Türkan Gök Yetkin Aygün Muhittin 《Research on Chemical Intermediates》2017,43(11):6379-6393
Research on Chemical Intermediates - This article describes synthesis of N-morpholinoethylbenzimidazole (1), 2-morpholinoethyl-substituted benzimidazolium salts (NHC precursors, 2a–c), and... 相似文献
5.
A new method based on microcolumn packed with ionic liquid-modified silica combined with flame atomic absorption spectrometry has been developed for the determination of lead in environmental samples. Several factors influencing the preconcentration efficiency of lead and its subsequent determination, such as pH of the sample, flow rate, mass of ionic liquid, and interfering effect, have been investigated. Lead could be quantitatively retained by ionic liquid-modified silica in the pH range of 5-7, and then eluted completely with 3.0 mL 1.0 mol L−1 HCl. The detection limit of this method for lead was 0.7 μg L−1 with preconcentration factor of 185, and the relative standard deviation (RSD) was 4.2% at 0.1 μg mL−1 Pb(II). This method has been applied for the determination of trace amount of lead in NIST standard reference material 2709 (San Joaquin Soil) and river water samples with satisfactory results. 相似文献
6.
Cemalettin Baltacı Huri İlyasoğlu Sevim Beyza Öztürk Sarıkaya Sevda Cavrar Nurettin Yaylı 《Accreditation and quality assurance》2011,16(10):507-513
A proficiency test (PT) was organized for quality control analysis of black tea. Test materials for the analyses of total
content of powder tea, moisture, total ash, acid-insoluble ash, water-soluble ash, alkalinity of water-soluble ash, water
extract, crude fiber and caffeine were sent to the participant laboratories (n:43) in 2009. The assigned value, standard deviation of the parameters and z-scores of the participant laboratories were calculated using the data reported by the participants. The percentage of the
reported results for analytes was found to be ranged from 67.5 to 100%. Acceptable z-scores were achieved by 80.5–97.5% of the participant laboratories. More than 15% of unacceptable results were obtained for
acid-insoluble ash and caffeine analyses. The quality control material for quality control analysis of black tea was developed
from the remaining material. 相似文献
7.
8.
Sevda Yldz Fadime Dirik Kamil Demirci 《Mathematical Methods in the Applied Sciences》2019,42(16):5371-5382
In this paper, we study the Korovkin type approximation theorem for Ka‐ convergence, which is an interesting convergence method on weighted spaces. We also study the rate of Ka?convergence by using the weighted modulus of continuity and afterwards, we present a nontrivial application. 相似文献
9.
Positivity - We prove a Korovkin-type approximation theorem using the relative uniform convergence of a sequence of functions at a point, which is a method stronger than the classical ones. We give... 相似文献
10.
In this paper, using the concept of statistical A-summability which is stronger than the A-statistical convergence we provide a Korovkin-type approximation theorem on the space of all continuous real valued functions defined on any compact subset of the real two-dimensional space. We also study the rates of statistical A-summability of positive linear operators. 相似文献