Search results for "complex"
showing 10 items of 5889 documents
Raman spectroscopy of glycolic acid complexes with N2
2019
High overtone excitation induced conformational isomerization of glycolic acid – nitrogen complex in an argon matrix was investigated by Raman spectroscopy. The interaction between glycolic acid and nitrogen change the green light (532 nm) induced isomerization processes compared to non-complexed glycolic acid. The 180° rotation around of the Csingle bondC bond and stabilization of carboxyl Odouble bondCsingle bondOsingle bondH dihedral angle to trans position were the main conformational changes observed in the complex of the lowest energy conformer and nitrogen. Interestingly, only one stable light-induced conformational product was observed, which isomerises back to the lowest energy con…
Earnings Premiums in Academia: Evidence from Personnel Data
2013
This study examines the existence of a gender earnings gap in the academic labour market with well-defined pay scales with panel data from the personnel records of a large university. We find that women earn approximately 10% less than men but that adjusting for different background characteristics and research performance decreases the gap to 2%. Our results suggest that the level of gender pay inequality is greater among older employees and lower for more productive employees. The results also imply that the gender gap is more pronounced in female-led departments than in male-led departments. peerReviewed
Transitions out of unemployment: The role of social networks' topology and firms' recruitment strategies
2011
In this paper we study the effects of job contact networks on out-of-unemployment transitions. We find that social connections produce sizable increases in upward mobility from unemployment and, caeteris paribus, symmetric network topologies perform better than asymmetric ones. Furthermore, in scale-free networks the probability of transitions out of unemployment increases in the exponent of the power-law degree distribution, but its value is much lower than the one attainable in Poisson random networks. In addition, and most interestingly, these results strongly depends on the different hypotheses on the firms' recruitment strategy.
Electronic spectroscopy of I2-Xe complexes in solid Krypton
2012
In the present work, we have studied ion-pair states of matrix-isolated I2 with vacuum-UV absorption and UV-vis-NIR emission, where the matrix environment is systematically changed by mixing Kr with Xe, from pure Kr to a more polarizable Xe host. Particular emphasis is put on low doping levels of Xe that yield a binary complex I2–Xe, as verified by coherent anti-Stokes Raman scattering (CARS) measurements. Associated with interaction of I2 with Xe we can observe strong new absorption in vacuum-UV, redshifted 2400 cm−1 from the X → D transition of I2. Observed redshift can be explained by symmetry breaking of ion-pair states within the I2–Xe complex. Systematic Xe doping of Kr matrices shows…
Defining Complexity Factors for Architecture Evaluation Framework
2006
The design and implementation of telecommunication systems is an incremental and iterative process, and system architectures may need to be revised and refined several times during their lifetime. Formal evaluation facilitates the identification of the weak points, where improvements are due in these architectures. In the domain of telecommunications, such evaluation can be based on the Architecture Evaluation Framework (AEF). During the evaluation, a deep understanding of the processes within a system is needed. Meanwhile, the systems being designed are usually complex systems encompassing a large number of components with an intricate pattern of interaction between them. As a result, it i…
A New Feature Selection Methodology for K-mers Representation of DNA Sequences
2015
DNA sequence decomposition into k-mers and their frequency counting, defines a mapping of a sequence into a numerical space by a numerical feature vector of fixed length. This simple process allows to compare sequences in an alignment free way, using common similarities and distance functions on the numerical codomain of the mapping. The most common used decomposition uses all the substrings of a fixed length k making the codomain of exponential dimension. This obviously can affect the time complexity of the similarity computation, and in general of the machine learning algorithm used for the purpose of sequence analysis. Moreover, the presence of possible noisy features can also affect the…
Synteza i charakterystyka kompleksów tytanu kowalencyjnie związanych z nośnikiem krzemionkowym oraz ich właściwości katalityczne w (ko)polimeryzacji …
2017
Zsyntezowano i scharakteryzowano dwa nowe ligandy wielodonorowe, amino-bis(fenolanowy) oraz fenoksyiminowy, kowalencyjnie związane z nośnikiem krzemionkowym, które następnie poddano reakcji z TiCl4. Zsyntezowane nośnikowe kompleksy tytanu, po uprzedniej ich aktywacji przy użyciu różnych związków glinoorganicznych oraz tetrakis(pentafluorofenylo)boranu tritylu, przetestowano w homopolimeryzacji etylenu i 1-oktenu, oraz w kopolimeryzacji tych olefin. Badane katalizatory wykazują niewielką aktywność w tych procesach, przy czym najaktywniejszy okazał się kompleks 1 zawierający ligand amino-bis(fenolanowy) aktywowany MAO. Kompleks ten polimeryzuje również 1-okten, dając produkt o zawartości pent…
Postęp badań w zakresie polimeryzacji olefin
2011
Na podstawie obszernego przeglądu literatury omówiono rozwój katalizatorów metaloorganicznych stosowanych w procesie polimeryzacji olefin z uwzględnieniem najnowszych badań w tym zakresie. Przedstawiono możliwości otrzymywania z ich udziałem produktów o różnej strukturze i właściwościach. Na tle postępu w technologii otrzymywania poliolefin scharakteryzowano wyniki najnowszych prac zespołu opolskiego, od wielu lat biorącego aktywny udział w badaniach nad opracowaniem i oceną właściwości katalitycznych kolejnych, nowych grup metaloorganicznych katalizatorów polimeryzacji i kopolimeryzacji olefin. Szczególną uwagę poświęcono katalizatorom zaliczanym do grupy układów postmetalocenowych z ligan…
Pt(II) and Pd(II)-assisted coupling of nitriles and 1,3-diiminoisoindoline : Synthesis and luminescence properties of (1,3,5,7,9-pentaazanona-1,3,6,8…
2017
Treatment of trans-[PtCl2(NCR)2] 1 (R = Me (1a), Et (1b), o-ClC6H4 (1c), p-ClC6H4 (1d), p-(HCdouble bond; length as m-dashO)C6H4 (1e), p-O2NC6H4CH2 (1f)) with 1,3-diiminoisoindoline HNdouble bond; length as m-dashCC6H4C(NH)double bond; length as m-dashNH 2 gives access to the corresponding (1,3,5,7,9-pentaazanona-1,3,6,8-tetraenato)Pt(II) complexes [PtCl{NHdouble bond; length as m-dashC(R)Ndouble bond; length as m-dashC(C6H4)NCdouble bond; length as m-dashNC(R)double bond; length as m-dashNH}] 3a–f, in good yields (65–70%). The reaction of trans-[PdCl2(NCMe)2] 4a with 2 furnishes (1,3,5,7,9-pentaazanona-1,3,6,8-tetraenato)Pd(II) complex [PdCl{NHdouble bond; length as m-dashC(Me)Ndouble bond…
Synthesis and Solid-State X-ray Structure of the Mononuclear Palladium(II) Complex Based on 1,2,3-Triazole Ligand
2022
Herein, we described the synthesis and X-ray crystal structure of the new [Pd(3)2Cl2] complex with 1,2,3-triazole-based ligand (3). In the unit cell, there are two [Pd(3)2Cl2] molecules, and the asymmetric unit comprised half of this formula due to the presence of an inversion symmetry element at the Pd(II) center. The monoclinic unit cell volume is 1327.85(6) Å3, with crystal parameters of a = 10.7712(2) Å, b = 6.8500(2) Å, and c = 18.2136(6) Å, while β = 98.851(2)°. The structure comprised two trans triazole ligand units coordinated to the Pd(II) ion via one of the N-atoms of the triazole moiety. In addition, the Pd(II) is further coordinated with two tran…