Resistivity of the 4d Transition Series Ru‐Rh‐Pd‐Ag Containing Fe

1968 ◽  
Vol 39 (2) ◽  
pp. 699-701 ◽  
Author(s):  
M. P. Sarachik
Keyword(s):  
Transition Series

scholarly journals Ethnic face categorization by Russians and Tuvinians in discrimination tasks

2019 ◽  
Vol 12 (4) ◽  
pp. 120-141
Author(s):  
V.N. Kharitonov ◽  
I.A. Basyul ◽  
K.I. Ananyeva ◽  
N.O. Tovuu
Keyword(s):  
Task Performance ◽  
Ethnic Groups ◽  
Communication Skills ◽  
Dual Task ◽  
Maximum Efficiency ◽  
Small Scale ◽  
Isolated Populations ◽  
Face Categorization ◽  
Transition Series ◽  
Large Groups

The opposite tendencies towards blurring the boundaries of compact living of ethnic groups and of relocation of large groups of strangers into the territories of compact residence of local groups generate a number of specific phenomena connected with the inter-group perception. We conducted a comparative study of perception and communication of transition series of “ethnic faces” among two small-scale isolated populations and representatives of the corresponding ethnic groups in multi-ethnic cities. The participants were to solve two discrimination task, one individually, the AB=X task, the other one, the dual “same-different” task, in dyads. For all samples of subjects, of In the AB=X task, the maximum discrimination efficiency was recorded for the same no. 2—3 pair of transition images series This may indicate that all subjects relied on the morphological features stimulus faces than on anything else. Also a tendency is observed toward similarity in the dynamics of efficiency of task performance in different groups of subjects, with the exception of the sample of Russians from the metropolis. At the same time, in the dyadic experiment, subjects from megacities demonstrate different trends in terms of the maximum efficiency of task performance. The sample of Russian subjects from Moscow demonstrates a significantly smaller decrease in efficiency when approaching the edges of the transitional series of stimulus images in the AB=X task, but not in the dual task. This is probably due to different nature of the tasks, i.e. one may easily suppose a more developed ability to perceptually discriminate between ethnic faces resulting from their greater variety in the environment, as in Moscow megacity, whereas it does not seem reasonable to suppose difference in communication skills required to perform the dual task across the samples.

scholarly journals Medicinal Utility of Some Schiff Bases and their Complexes with First Transition Series Metals: A Review

2021 ◽  
Vol 37 (5) ◽  
pp. 1051-1061
Author(s):  
Tahmeena Khan ◽  
Saima Zehra ◽  
Almas Alvi ◽  
Umama Fatima ◽  
Alfred J. Lawrence
Keyword(s):  
Transition Metal ◽  
Metal Complexes ◽  
Transition Metal Complexes ◽  
Present Review ◽  
Potential Drug ◽  
Drug Candidates ◽  
Transition Series ◽  
Low Toxicity ◽  
Activity Enhancement

Schiff based ligands and their complexes have emerged as potential drug candidates. Owing to their excellent chelating tendency, they easily coordinate with transition metals which have vacant orbitals. Transition metal complexes have several advantages because of their better acceptability and low toxicity in biological systems. These metals also serve as micronutrients and as co-factors of various metallo-enzymes which justifies the need of their designing and synthesis. Many modifications have been suggested in the ligand moiety for the purpose of activity enhancement and some of them have been described in the present review. These modifications have enhanced better potency against a number of diseases and resulting in low toxicity and better solubility in vivo. The transition metal complexes with Schiff based complexes have exhibited an array of activities including anticancer, antioxidant and antimicrobial. Their analytical applications have also been reported. The present review summarizes some of the recent advances in the field of synthesis and designing of new Schiff based complexes particularly with first transition series metals and their medicinal applications.

Electronic Spectra of Titania-Supported First Transition Series Cations

1987 ◽  
Vol 20 (3) ◽  
pp. 201-211 ◽  
Author(s):  
M. del Arco ◽  
M. J. Holgado ◽  
C. Martin ◽  
V. Rives
Keyword(s):  
Electronic Spectra ◽  
Transition Series

Electron ionization mass spectrometry of aryl- and fluoroalkyl-substituted palladium(II) β-diketonates and monothio-β-diketonates

1994 ◽  
Vol 72 (5) ◽  
pp. 1302-1311 ◽  
Author(s):  
Mark L. J. Reimer ◽  
John B. Westmore ◽  
Manoranjan Das
Keyword(s):  
Mass Spectra ◽  
Electron Ionization ◽  
Electron Ionization Mass Spectrometry ◽  
Ionization Mass ◽  
Aryl Group ◽  
Mass Spectral ◽  
Transition Series ◽  
Electron Ionization Mass Spectra ◽  
Positive Ion ◽  
Sulfur Donor

Positive ion electron ionization mass spectra are presented for palladium(II) β-diketonates and monothio-β-diketonates of the general form PdII[RC(X)CHC(O)R′]2, where R = phenyl, 4-methoxyphenyl, 2-thienyl, or 2-naphthyl; R′ = trifluoromethyl, pentafluoroethyl, or n-heptafluoropropyl; and X = O or S. The mass spectral behavior is in sharp contrast to that of metals of the first transition series. The spectra of the β-diketonates are dominated by metal-containing ions that arise by migration of the R group from the ligand (L) to palladium, but there is no evidence for fluorine-to-metal transfer. These findings are consistent with HSAB theory. The strong tendency of palladium to form bonds with unsaturated carbon also leads to remarkably abundant metal-containing ions that arise by losses of CO or aryloxy radicals from [PdRL]+• ions. In contrast, in decompositions of ions in the spectra of the monothio-β-diketonates, migration of the R group is suppressed; competition for palladium dπ electrons by the sulfur donor makes palladium a poorer aryl group acceptor.

Thermodynamic of metal complexation of the macrocyclic antibiotic rifampicin

2001 ◽  
Vol 79 (1) ◽  
pp. 42-49
Author(s):  
I Shehatta ◽  
I Kenawy ◽  
A H Askalany ◽  
Ayman A Hassan
Keyword(s):  
Binding Sites ◽  
Equilibrium Constants ◽  
Ionic Species ◽  
Ligand Field ◽  
Water Medium ◽  
Acid Base ◽  
Distribution Diagram ◽  
Macrocyclic Antibiotic ◽  
Transition Series ◽  
Different Temperatures

The acid-base and complexation equilibria of rifampicin with H+, Mn2+, Co2+, Ni2+, Cu2+, Zn2+, Cd2+, Hg2+, and Pb2+ were studied by means of potentiometry. The stoichiometric equilibrium constants were determined in 50% (v/v) methanol-water medium at different temperatures and constant ionic strength (0.05 M KCl). It was established that rifampicin has two proton-binding sites. The distribution diagram of the corresponding ionic species as a function of pH is given and indicated that rifampicin exists predominantly in the zwitterionic form at pH [Formula: see text] 5. The thermodynamic parameters of protonation and complexation were derived and discussed. The formation of the complexes is spontaneous, more favourable at lower temperatures, entropically unfavourable, and an enthalpy-driven process. The order of the changes in Gibbs energy and enthalpy accompanying the complexation was found to be Mn2+ < Co2+ < Ni2+ < Cu2+ > Pb2+ > Zn2+ > Cd2+ > Hg2+ in accordance with the well-known sequence of Irving and Williams. The transition series contraction energy (Er(Mn-Zn)), and the ligand field stabilization energy (δH) were calculated from the enthalpy changes.Key words: rifampicin, thermodynamics, potentiometry, and complexation.

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