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61.
62.
We carry out extensive first-principles doping-dependent computations of angle-resolved photoemission (ARPES) intensities in La2-xSrxCuO4 over a wide range of binding energies. Intercell hopping and the associated three dimensionality, which is usually neglected in discussing cuprate physics, is shown to play a key role in shaping the ARPES spectra. Despite the obvious importance of strong coupling effects (e.g., the presence of a lower Hubbard band coexisting with midgap states in the doped insulator), a number of salient features of the experimental ARPES spectra are captured to a surprising extent when kz dispersion is properly included in the analysis. 相似文献
63.
D. Czakis-Sulikowska J. Radwańska-Doczekalska M. Markiewicz 《Journal of Thermal Analysis and Calorimetry》2000,60(1):145-151
The mixed 2,4'-bipyridine-oxalato complexes of the formulae M(2,4'-bipy)2 C2 O4 2H2 O (M (II)=Mn, Co, Ni, Cu; 2,4'-bipyridine=2,4'-bipy or L ; C2 O2–
4 =ox) have been prepared and characterized. IR data show that the 2,4'-bipy coordinated with these metals(II) via the least
hindered (4')N atom; that oxalate group acts as bidentate chelating ligand. Room temperature magnetic moments are normal for
the orbital singlet states. The thermal decomposition of these complexes was investigated by TG, DTA and DTG in air. The endothermic
or exothermic character of the decomposition of ML2 (ox)2H2 O was discussed.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
64.
D. Czakis-Sulikowska J. Radwańska-Doczekalska A. Czylkowska M. Markiewicz A. Broniarczyk 《Journal of Thermal Analysis and Calorimetry》2006,86(2):327-335
New mixed-ligand complexes with empirical
formulae: Mn(2-bpy)1.5L2·2H2O,
M(2-bpy)2L2·3H2O
(M(II)=Co, Cu), Ni(2-bpy)3L2·4H2O
and M(2,4’-bpy)2L2·2H2O
(where 2-bpy=2,2’-bipyridine, 2,4’-bpy=2,4’-bipyridine; L=HCOO– ) have been
obtained in pure solid-state. The complexes were characterized by chemical
and elemental analysis, IR and VIS spectroscopy, conductivity (in methanol
and dimethylsulfoxide). The way of metal-ligand coordination discussed. The
formate and 2,4’-bpy act as monodentate ligands and 2-bpy as chelate
ligand. The new complexes with ligand isomerism were identified. During heating
the complexes lose water molecules in one or two steps. Thermal decomposition
after dehydration is multistage and yields corresponding metal oxides as final
products. A coupled TG-MS system was used to analysis principal volatile thermal
decomposition (or fragmentation) products of Ni(2,4’-bpy)2(HCOO)2·2H2O under dynamic air or argon atmosphere. 相似文献
65.
We propose a new method for computing a large number of eigenpairs in the interior of the spectrum for conservative gyroscopic eigenproblems by the nonlinear Arnoldi method combined with a localized version of safeguarded iteration. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
66.
Katarzyna Markiewicz Anna Biak-Bieliska Paulina ukaszewicz Piotr Stepnowski Joanna Doonek 《Molecules (Basel, Switzerland)》2021,26(6)
Nowadays anticancer drugs (ADs), like other pharmaceuticals, are recognized as new emerging pollutants, meaning that they are not commonly monitored in the environment; however, they have great potential to enter the environment and cause adverse effects there. The current scientific literature highlights the problem of their presence in the aquatic environment by publishing more and more results on their analytics and ecotoxicological evaluation. In order to properly assess the risk associated with the presence of ADs in the environment, it is also necessary to investigate the processes that are important in understanding the environmental fate of these compounds. However, the state of knowledge on mobility of ADs in the environment is still very limited. Therefore, the main aim of our study was to investigate the sorption potential of two anticancer drugs, 5-fluorouracil (5-FU) and methotrexate (MTX), onto different soils. Special attention was paid to the determination of the influence of pH and ionic strength as well as presence of co-contaminants (cadmium (Cd2+) and another pharmaceutical—metoprolol (MET)) on the sorption of 5-FU and MTX onto soil. The obtained distribution coefficient values (Kd) ranged from 2.52 to 6.36 L·kg−1 and from 6.79 to 12.94 L·kg−1 for 5-FU and MTX, respectively. Investigated compounds may be classified as slightly or low mobile in the soil matrix (depending on soil). 5-FU may be recognized as more mobile in comparison to MET. It was proved that presence of other soil contaminants may strongly influence their mobility in soil structures. The investigated co-contaminant (MET) caused around 25-fold increased sorption of 5-FU, whereas diminished sorption of MTX. Moreover, the influence of environmental conditions such as pH and ionic strength on their sorption has been clearly demonstrated. 相似文献
67.
Practical Iron‐ and Cobalt‐Catalyzed Cross‐Coupling Reactions between N‐Heterocyclic Halides and Aryl or Heteroaryl Magnesium Reagents 下载免费PDF全文
Dr. Olesya M. Kuzmina Dr. Andreas K. Steib M. Sc. Sarah Fernandez Willy Boudot Dr. John T. Markiewicz Prof. Dr. Paul Knochel 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(22):8242-8249
The reaction scope of iron‐ and cobalt‐catalyzed cross‐coupling reactions in the presence of isoquinoline (quinoline) in the solvent mixture tBuOMe/THF has been further investigated. Various 2‐halogenated pyridine, pyrimidine, and triazine derivatives were arylated under these mild conditions in excellent yields. The presence of isoquinoline allows us to perform Fe‐catalyzed cross‐coupling reactions between 6‐chloroquinoline and aryl magnesium reagents. Furthermore, it was found that the use of 10 % N,N‐dimethylquinoline‐8‐amine increases the yields of some Co‐catalyzed cross‐coupling reactions with chloropyridines bearing electron‐withdrawing substituents. 相似文献
68.
69.
Marian Olszowy Ewa Markiewicz Czesław Pawlaczyk Ewa Nogas-Ćwikiel 《Phase Transitions》2013,86(11-12):1099-1106
Dielectric response of poly(vinyl chloride), (PVC), loaded with different amount of Ba0.3Na0.7Ti0.3Nb0.7O3 (BNTN) ceramic powders was investigated in frequency range 100 Hz–1 MHz and temperature range 100–450 K. Ceramic solid solution of barium titanate and sodium niobate with composition Ba0.3Na0.7Ti0.3Nb0.7O3 was obtained from BaCO3, TiO2, Na2CO3 and Nb2O5 by conventional method. Powders were prepared by grinding of ceramics. The obtained ceramics, used to produce BNTN–PVC composites, are characterized by the relaxor behaviour with a broad peak of dielectric permittivity ε′ at T m ≈ 230 K. The microstructure of the powders was observed and the grain size was estimated using scanning electron microscope Hitachi S-4700. The EDS analysis confirms the qualitative and quantitative chemical composition of powders and ceramics. The BNTN–PVC composite samples of 0-3 connectivity were prepared from ceramic and polymer powders by hot-pressing method. The dielectric response of the composites displays features originated from the PVC polymer modified by those of BNTN ceramics. The relaxation time of the α-process of PVC obeys the Vogel–Fulcher law and decreases with increasing volume fraction of the ceramics. 相似文献
70.
Wanda Radecka‐Paryzek Izabela Pospieszna‐Markiewicz Maciej Kubicki 《Acta Crystallographica. Section C, Structural Chemistry》2006,62(7):o399-o401
In the title salt, also known as pentane‐1,5‐diammonium dichloride, C5H16N22+·2Cl−, the cation exists in an ideal fully extended conformation and lies on a mirror plane in the space group Pbam. In the crystal structure, layers of cations are hydrogen bonded with Cl− anions, which occupy the space between the layers. This kind of packing leads to a short unit‐cell parameter of 4.463 (1) Å. This structure is another case of centro–non‐centrosymmetric ambiguity; the best results were obtained in a centrosymmetric space group, with the disordered NH3 groups accounting for the non‐centrosymmetric `component'. 相似文献