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11.
Tulika Ghosh Abhik Mukhopadhyay Kummari S. C. Dargaiah Samudranil Pal 《Structural chemistry》2010,21(1):147-152
Reactions of Ni(O2CCH3)2·4H2O and Cu(O2CCH3)2·H2O with biacetyl bis(benzoylhydrazone) (H2babh) in alcoholic media afford mononuclear nickel(II) and copper(II) complexes of general formula [M(babh)]. The complexes
have been characterized by microanalysis (C, H, N), magnetic susceptibility, and various spectroscopic measurements. X-ray
structures of both complexes have been determined. The metal centre in [Ni(babh)] is in square-planar N2O2 environment provided by the tetradentate babh2−. On the other hand, [Cu(babh)] crystallizes as distorted square-pyramidal [Cu(babh)(CH3OH)] from methanol. Here the tetradentate babh2− constitutes the N2O2 square-base and the O-coordinating methanol occupies the apical site. In the crystal lattice, the molecules of [Ni(babh)]
form a one-dimensional π-stacked structure. The [Cu(babh)(CH3OH)] molecules also form a one-dimensional structure with alternating long and short Cu···Cu distances via intermolecular
O–H···N hydrogen bonding and π–π interaction. 相似文献
12.
A. V. Karnik N. J. Malviya A. M. Kulkarni D. Jaimini B. L. Jadhav 《Journal of heterocyclic chemistry》2006,43(2):489-493
13.
Vandana Singh Preeti Srivastava Angela Singh Devendra Singh Tulika Malviya 《高分子科学杂志,C辑:聚合物评论》2016,56(1):113-136
This article discusses and reviews the current status and future perspectives of silica hybrids of polysaccharides and biosilicas derived thereof. The hybrids have been produced in various morphological shapes and utilized in water remediation, separation, enzyme immobilization, sensor, and biomedical fields. The polysaccharides show templating and structure directing influence in manipulation of sol gel silica hybrid materials which can be calcined to derive functional biosilicas. The development of energy storage devices and white light emitting solid phosphors may be the fields of future research. 相似文献
14.
Russian Journal of Electrochemistry - A novel, convenient and economical method was developed for the anodic thiocyanation of nitrogen-containing aromatic and heteroaromatic compounds by constant... 相似文献
15.
In view of recent controversy regarding the orbital order in the frustrated spinel ZnV(2)O(4), we analyze the orbital and magnetic ground state of this system within an ab initio density functional theory approach. While local density approximation+Hubbard U calculations in the presence of a cooperative Jahn-Teller distortion stabilize an A-type staggered orbital order, the consideration of relativistic spin-orbit (SO) effects unquenches the orbital moment and leads to a uniform orbital order with a net magnetic moment close to the experimental one. Our results show that ab initio calculations are able to resolve the existing discrepancies in previous theories and that it is the SO coupling along with electronic correlations which play a significant role in determining the orbital structure in these materials. 相似文献
16.
A sulfite oxidase (SOx) purified from leaves of Syzygium cumini (Jamun) was immobilized covalently onto a gold nanoparticles (AuNPs)/chitosan (CHIT)/carboxylated multiwalled carbon nanotubes
(cMWCNTs)/polyaniline (PANI) composite that was electrodeposited onto the surface of a gold (Au) electrode. A novel and highly
sensitive sulfite biosensor was developed that used this enzyme electrode (SOx/AuNPs/CHIT/cMWCNT/PANI/Au) as the working electrode,
Ag/AgCl as the standard electrode, and Pt wire as the auxiliary electrode. The modified electrode was characterized by Fourier
transform infrared (FTIR) spectroscopy, cyclic voltammetry (CV), scanning electron microscopy (SEM), and electrochemical impedance
spectroscopy (EIS) before and after the immobilization of the SOx. The sensor produced its optimum response within 3 s when
operated at 50 mVs−1 in 0.1 M phosphate buffer, pH 7.0, and at 35 °C. The linear range and detection limit of the sensor were 0.75–400 μM and
0.5 μM (S/N = 3), respectively. The biosensor was employed to determine sulfite levels in fruit juices and alcoholic beverages.
The enzyme electrode was used 300 times over a period of three months when stored at 4 °C. 相似文献
17.
Tulika Chakraborty Satyaveer S. Chauhan Bibhas C. Giri 《Applied Mathematical Modelling》2013,37(10-11):6593-6608
In this article we develop an economic manufacturing quantity (EMQ) model subject to stochastic machine breakdown, repair and stock threshold level (STL). Instead of constant production rate, in this model production rate is considered as a decision variable. Since, the stress of the machine depends on the production rate, failure rate of the machine will be a function of the production rate. Again, in this article consideration of safety stock in all existing literature is replaced by the concept of stock threshold level (STL). Further, extra capacity of the machine is considered to buffer against the possible uncertainties of the production process where machine capacity is predetermined. The basic model is developed under general failure and general repair time distributions. Since, the assumption of variable production rate makes the objective function quite complex, so main emphasis is given on computational methodology to solve the present problem. We suggest two computational algorithms for the determination of production rate and stock threshold level which minimize the expected cost rate in the steady state. Finally, through numerical examples we illustrate the key insights of our model from managerial point of view. 相似文献
18.
Mukherjee T Sarkar T Paul P Chakraborty AK Jaisankar P Mukhopadhyay SB 《Natural product communications》2012,7(4):511-513
Chemical investigation of the leaves of Putranjiva roxburghii has resulted in the isolation of two new triterpenoids, putralone, a novel 10alpha-hydroxy-25-nor D:A friedo-olean-9(11)-en-3 one and 3beta-acetoxy-cycloart-24-en-23-one, along with a rare hopanoid, adian-5-en-3beta,29-diol. Other known triterpenoids isolated from this plant are 3beta-acetoxy-adian-5-ene, putrol, putrone, putranjivadione, roxburghonic acid, friedelin, friedlan-3alpha-ol, oleanolic acid and erythrodiol. Interestingly, putralone is the first example of a naturally occurring nor friedo-oleanane triterpenoid having a hydroxyl functionality at the C-10 position. 相似文献
19.
The removal of arsenic ions from dilute aqueous solutions using biopolymeric beads of crosslinked sodium alginate and carboxymethyl cellulose (CMC) as the adsorbent is reported in this paper. The biopolymeric alginate and carboxymethyl cellulose beads were prepared and characterized by FTIR spectra. On the surfaces of the prepared beads were performed static and dynamic adsorption studies of arsenic ions at fixed pH and ionic strength of the aqueous metal ion solutions. The adsorption data were applied to Langmuir and Freundlich isotherm equations and various static parameters were calculated. The dynamic nature of adsorption was quantified in terms of several kinetic constants such as rate constant for adsorption (k1) and Lagergreen rate constant (Kad). The influence of various experimental parameters such as solid to liquid ratio, pH, temperature, presence of salts and chemical composition of biopolymeric beads were investigated on the adsorption of arsenic ions. 相似文献
20.
Ashish Kumar Venugopal Singamaneni Sudheer K Dokuparthi Tulika Chakrabarti 《Natural product research》2018,32(5):582-587
Chemical investigation of root bark of Glycosmis pentaphylla and stem bark of Tabernaemontana coronaria led to the isolation of three carbazole alkaloids glycozoline, glycozolidine and methyl carbazole 3-carboxylate, two furoquinoline alkaloids skimmianine and dictamine, an acridone alkaloid arborinine, three monomeric indole alkaloids coronaridine, 10-methoxy coronaridine and tabernaemontanine, and two dimeric indole alkaloids voacamine and tabernaelegantine B. Their structures were established by detailed spectral analysis. Mutagenic and antimutagenic potential of methanol extract of both plant materials were evaluated by Ames test against known positive mutagens 2-aminofluorine, 4-nitro-O-phenylenediamine and sodium azide using Salmonella typhimurium TA 98 and TA 100 bacterial strains both in the presence and absence of S9. Both the extracts were non-mutagenic in nature. Both the extracts of G. pentaphylla and T. coronaria exhibited significant antimutagenic activity against NPD and sodium azide for S. typhimurium TA98 and TA100 strains. The results indicated that the extracts could counteract the mutagenicity induced by different genotoxic compounds. 相似文献