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1.
Applications of electronic speckle interferometry (ESI) techniques for spacecraft structural components 总被引:1,自引:0,他引:1
Laser-based electronic speckle interferometry (ESI) techniques, viz., electronic speckle pattern interferometry (ESPI) and electronic speckle shearographic interferometry (ESSI) are used for testing of spacecraft structural components. The combined ESPI and ESSI system developed in house was successfully used for the non-destructive evaluation (NDE) of honeycomb sandwich panels and propellant tanks of Indian Space Research Organization (ISRO). Debonds between face sheet and the honeycomb core were identified using (i) thermal and (ii) dual vacuum stressing methods. On-line NDE of the propellant tanks under internal pressure loading for identification of the minute cracks and thickness reduction areas were successfully implemented by ESI. 相似文献
2.
C. J. Shishoo M. B. Devani G. V. Ullas S. Ananthan V. S. Bhadti 《Journal of heterocyclic chemistry》1988,25(2):615-622
5H-Triazolo[1,5-d]- and 5H-tetrazolo[1,5-d]thieno[3,2-f]-1,4-diazepin-6(7H)-ones have been obtained by the base catalysed ring expansion reaction of 5-chloromethyl-1,2,4-triazolo[1,5-c]- and 5-chloromethyltetrazolo- [1,5-c]thieno[3,2-e]pyrimidines. The required thienopyrimidine derivatives were synthesized from 2-amino-3-triazolyl- and 2-amino-3-tetrazolylthiophenes by acylation, followed by dehydrative cyclization. 相似文献
3.
Reactivity of [M2(μ‐Cl)2(cod)2] (M=Ir,Rh) and [Ru(Cl)2(cod)(CH3CN)2] with Na[H2B(bt)2]: Formation of Agostic versus Borate Complexes 下载免费PDF全文
K. Bakthavachalam K. Yuvaraj Mohammad Zafar Prof. Dr. Sundargopal Ghosh 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(48):17291-17297
Treatment of [M2(μ‐Cl)2(cod)2] (M=Ir and Rh) with Na[H2B(bt)2] (cod=1,5‐cyclooctadiene and bt=2‐mercaptobenzothiazolyl) at low temperature led to the formation of dimetallaheterocycles [(Mcod)2(bt)2], 1 and 2 ( 1 : M=Ir and 2 : M=Rh) and a borate complex [Rh(cod){κ2‐S,S′‐H2B(bt)2}], 3 . Compounds 1 and 2 are structurally characterized metal analogues of 1,5‐cyclooctadiene. Metal–metal bond distances of 3.6195(9) Å in 1 and 3.6749(9) Å in 2 are too long to consider as bonding. In an attempt to generate the Ru analogue of 1 and 2 , that is [(Rucod)2(bt)2], we have carried out the reaction of [Ru(Cl)2(cod)(CH3CN)2] with Na[H2B(bt)2]. Interestingly, the reaction yielded agostic complexes [Ru(cod)L{κ3‐H,S,S′‐H2B(bt)2}], 4 and 5 ( 4 : L=Cl; 5 : L=C7H4NS2). One of the key differences between 4 and 5 is the presence of different ancillary ligands at the metal center. The natural bond orbital (NBO) analysis of 1 and 2 shows that there is four lone pairs of electrons on each metal center with a significant amount of d character. Furthermore, the electronic structures and the bonding of these complexes have been established on the ground of quantum‐chemical calculations. All of the new compounds were characterized by IR, 1H, 11B, 13C NMR spectroscopy, and X‐ray crystallographic analysis. 相似文献
4.
Deena Gladies Raymond Mohanraj Manikandan Alagumuthu Palaniraja Subramaniam Dhivya Bakthavachalam Sivakumar Arumugam Subha Chellam 《Journal of heterocyclic chemistry》2021,58(7):1515-1524
In this study, the antimicrobial effect and DNA gyrase inhibitor potential of vanillin-based pyridyl–substituted fluoro-indolines were evaluated. These compounds are synthesized and established through green-chemistry approaches. The inhibition effect on both DNA gyrase A and B was evaluated in silico and in vitro. Agar well diffusion method–based antimicrobial activity against Gram-ve Pseudomonas aeruginosa (MTCC 424) and Escherichia coli (MTCC 443), Gram+ve Streptococcus pyogenes (MTCC 442) and Staphylococcus aureus (MTCC 96), and a clinical isolate of Candida albicans (Fungi) was evaluated. The cytotoxicity of the compounds was assessed over macrophages using the MTT assay. In the results, the target compounds exhibited a broad-spectrum antimicrobial activity against both bacterial types and fungal. 相似文献
5.
Herein we utilized, for the first time, 2-iodoxybenzoate along with scandium triflate as a specific oxidant for PhthNH2 to create sulfoximines. This method efficiently effects imination of aryl, benzyl, cyclic and alkyl substituted S?O bonds with good to excellent yields. In addition, sterically encumbered sulfoxides have been studied and found that the present protocol is the worthy choice. This facile method does not require either inert atmosphere or anhydrous solvents. 相似文献
6.
C.J. Shishoo M.B. Devani V.S. Bhadti S. Ananthan G.V. Ullas 《Tetrahedron letters》1984,25(12):1291-1292
Stable N-(carbethoxycyanovinyl)amidines have been isolated from the reaction of benzamidine with carbethoxycyanoketene S,N-acetals and have been found to cyclize to 4-chloro-, 4-amino- and 4-hydroxypyrimidines depending upon the cyclizing agent employed. 相似文献
7.
Synthesis,Structure, Bonding,and Reactivity of Metal Complexes Comprising Diborane(4) and Diborene(2): [{Cp*Mo(CO)2}2{μ‐η2:η2‐B2H4}] and [{Cp*M(CO)2}2B2H2M(CO)4], M=Mo,W 下载免费PDF全文
Dr. Bijan Mondal Ranjit Bag Sagar Ghorai Dr. K. Bakthavachalam Prof. Eluvathingal D. Jemmis Prof. Sundargopal Ghosh 《Angewandte Chemie (International ed. in English)》2018,57(27):8079-8083
The reaction of [(Cp*Mo)2(μ‐Cl)2B2H6] ( 1 ) with CO at room temperature led to the formation of the highly fluxional species [{Cp*Mo(CO)2}2{μ‐η2:η2‐B2H4}] ( 2 ). Compound 2, to the best of our knowledge, is the first example of a bimetallic diborane(4) conforming to a singly bridged Cs structure. Theoretical studies show that 2 mimics the Cotton dimolybdenum–alkyne complex [{CpMo(CO)2}2C2H2]. In an attempt to replace two hydrogen atoms of diborane(4) in 2 with a 2e [W(CO)4] fragment, [{Cp*Mo(CO)2}2 B2H2W(CO)4] ( 3 ) was isolated upon treatment with [W(CO)5?thf]. Compound 3 shows the intriguing presence of [B2H2] with a short B?B length of 1.624(4) Å. We isolated the tungsten analogues of 3 , [{Cp*W(CO)2}2B2H2W(CO)4] ( 4 ) and [{Cp*W(CO)2}2B2H2Mo(CO)4] ( 5 ), which provided direct proof of the existence of the tungsten analogue of 2 . 相似文献
8.
K. G. Dave C. J. Shishoo M. B. Devani R. Kalyanaraman S. Ananthan G. V. Ullas V. S. Bhadti 《Journal of heterocyclic chemistry》1980,17(7):1497-1500
Nitriles are known to give rise to salts of different compositions with halogen acids. Many of the reactions undergone by nitriles under the influence of halogen acids are, in many cases, assumed to proceed via the intermediate formation of highly reactive imidoyl derivatives. The intermediates produced, in situ, by the reaction of nitriles with hydrogen chloride should, in principle, be capable of reacting with compounds containing appropriately placed nucleophilic and electrophilic centers leading to the formation of a heterocycle incorporating the C=N of the nitrile. Thus, the reaction of aliphatic, aromatic and heterocyclic nitriles with a variety of ortho aminocarbonyl derivatives such as nitriles, amides, esters and ketones of benzene, thiophen, furan, pyrrole, benzothiophene and pyridothiophene have been found to yield the corresponding condensed pyrimidines in fair to good yields. This constitutes a facile and versatile one-pot synthesis of condensed pyrimidines. 相似文献
9.
10.
C. J. Shishoo M. B. Devani G. V. Ullas S. Ananthan V. S. Bhadti 《Journal of heterocyclic chemistry》1985,22(3):825-830
Synthesis of 2-(2-arylvinyl)thienopyrimidines, by the acid catalyzed condensation of nitriles with thiophene o-aminocarbonyl compounds, the condensation of aldehydes with thiophene o-aminoamides, the base catalyzed condensation of aldehydes with 2-methylthienopyrimidines and by the Wittig condensation of 2-thieno-pyrimidinylmethylphosphonium salts with aldehydes is described. Isomeric 5-methyltriazolothienopyrimidines were found to react, under basic condition, with aldehydes yielding 5-(2-arylvinyl)triazolo[2,3-c]thieno-pyrimidines. While 5-styryltriazolo[4,3-c] isomers resisted acid catalysed isomerization, they were found to isomerize to triazolo[2,3-c]pyrimidines under base catalysis. 相似文献