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101.
M. Kabešová I. Vargová T. Šramko J. Gažo 《Journal of Thermal Analysis and Calorimetry》1978,13(1):65-70
The influence of the position of the CH3 group in picoline and lutidine ligands on the degree of chemical change of the NCS groups in coordination compounds of the type Cu(NCS)2L2 (whereL=2-, 3- and 4-picoline, and 2,3-, 2,4-, 2,5-, 2,6-, 3,4- and 3,5-lutidine) is dealt with. The most marked effect of the CH3 group is found to be exerted in position 4. This effect of the methyl group on the degree of chemical change points to the mutual influence of the ligands in coordination compounds of Cu(II).
Zusammenfassung Der Artikel befaßt sich mit dem Einfluß der Lage der CH3 Gruppe in Pikolinen und Lutidinen als Liganden auf den Grad der chemischen Änderungen der Gruppen NSC in Koordinationsverbindungen des Typs Cu(NCS)2L2 (L=2-, 3- und 4-Pikoline, 2,3-, 2,4-, 2,5-, 2,6-, 3,4- und 3,5-Lutidine). Der ausgeprägteste Effekt der CH3 Gruppe wurde in der Position 4 beobachtet. Dieser Einfluß der Methylgruppe auf das Ausmaß der chemischen Änderungen deutet auch auf die gegenseitige Wirkung der Liganden in Koordinationsverbindungen von Cu(II).
Résumé L'article a trait à l'influence de la position du groupe CH2 dans les picolines et lutidines, en tant que ligands, sur le degré des changements chimiques des groupes SCN dans les composés de coordination du type Cu(SCN)2L2 (L=2-, 3 et 4-picoline, 2,3-, 2,4-,2,5-, 2,6-, 3,4- et 3,6-lutidine). L'effet le plus prononcé du groupe CH3 s'observe en position 4. Cette influence du groupe méthyle sur le degré des changements chimiques indique aussi l'influence mutuelle des ligands dans les composés de coordination du Cu(II).
- , , NCS Cu(NCS)2,L2, L=2-, 3- 4- , 2.3-, 2.4-, 2.5-, 2.6-, 3.4- 3.5-. , 4. Cu(II).相似文献
102.
R. Ramanauskas L. Gudavičiūtė A. Kaliničenko R. Juškėnas 《Journal of Solid State Electrochemistry》2005,9(12):900-908
The influence of pulse plating parameters on the surface morphology, grain size, lattice imperfection and corrosion properties
of Zn–Ni alloy has been studied. The coatings were electrodeposited in an alkaline cyanide-free solution. AFM was applied
for surface morphology examination, XRD measurements were carried out for phase composition and texture analysis, electron
probe microanalysis was used for alloy chemical composition studies, while electrochemical techniques were applied for corrosion
performance evaluation. The pulse plated Zn–Ni coatings appeared to consist of the γ-Zn21Ni5 phase and the composition of the alloy depended on the plating parameters. The grain size, lattice imperfection and homogeneity
of grain distribution were established to be the main factors determining corrosion behaviour of the coating.
Presented at the 4th Baltic Conference on Electrochemistry, Greifswald, March 13–16, 2005 相似文献
103.
Perišić-Janjić Nada U. Ž. Jovanović Bratislav Janjić Natasa J. Rajković Olga S. Antonović Dušan G. 《平面色谱法杂志一现代薄层色谱法》2003,16(6):425-432
JPC – Journal of Planar Chromatography – Modern TLC - The chromatographic behavior of nine newly synthesized s-tri-azines has been studied by thin-layer chromatography on C18/UV254... 相似文献
104.
Jadranka Vuković Shiro Matsuoka Kazuhisa Yoshimura Vladimir Grdinić Renata Jurišić Grubešić 《Mikrochimica acta》2007,159(3-4):277-285
A simple, sensitive and rapid solid-phase spectrophotometric procedure was developed for the determination of traces of phenol
with 4-aminoantipyrine as a reagent (AAP-SPS), and the optimal experimental conditions were established. This method was performed by sorption and direct absorbance measurements
of the product phenol-AAP sorbed on the anion-exchanger Dowex 1-X4 (0.2 g) at 495 nm (absorption maximum) and 700 nm (non-absorption wavelength). The
sensitivity offered by the AAP-SPS procedure was higher by a factor of 40 compared with the respective conventional spectrophotometric method. Metrological
characteristics were established using a prevalidation strategy. The AAP-SPS procedure is characterized by a linear calibration function in the working range of 0.05–0.50 μmol, low standard deviation
of procedure (±0.012), low limit of determination (0.021 μmol), and favorable random (±0.85 to ±11.27%) and systematic deviations
(−4.55 to +11.50%). Moreover, the accuracy of the system investigated by the recovery test is acceptable (99–102%). Favorable
working and performance characteristics make the new SPS method ideal for phenol monitoring in pharmaceutical preparations
as well as other matrices. 相似文献
105.
The effect of the biomass presence on the overall circulation velocity, the linear velocities both in the riser and the downcomer
and the overall gas hold-up was studied in a three-phase internal loop airlift reactor (ILALR). The measured data were compared
with those obtained using a two-phase system (air—water). All experiments were carried out in a 40 dm3 ILALR at six different biomass concentrations (ranging from 0 g dm−3 to 7.5 g dm−3), at a temperature of 30°C, under atmospheric pressure. Air and water were used as the gas and liquid model media, respectively.
Pellets of Aspergillus niger produced during the fermentation of glucose to gluconic acid in the ILALR were considered solid phase. In addition, liquid
velocities were measured during the fermentation of glucose to gluconic acid using Aspergillus niger. All measurements were performed in a bubble circulation regime. At given experimental conditions the effect of the biomass
on the circulation velocities in the ILALR was negligible. However, increasing of the biomass concentration led to lower values
of the total gas hold-up.
Presented at the 33rd International Conference of the Slovak Society of Chemical Engineering, Tatranské Matliare, 22–26 May
2006. 相似文献
106.
Žydrė Šaltienė Natalija Jatulienė Mudis Šalkauskas Daiva Brukštienė Asta Ruzgytė Aušra Tarasevičiūtė Julius Kalibatas 《Accreditation and quality assurance》2005,10(8):444-451
The estimation scheme of uncertainty of determination of 1-hydroxypyrene (1-OHP) in urine was developed analysing the main
stages of the analytical procedure: (1) preparation of 1-OHP standards, (2) creation of the calibration curve for the high
performance liquid chromatography (HPLC) analysis method with the evaluation of recovery, (3) measuring procedure of aliquot
of urine, (4) adjusting the pH of aliquot and hydrolysis with enzyme, (5) solid phase extraction, (6) concentration of the
extract, (7) injection of the extract to chromatograph and analysing by the HPLC method, (8) calculation of 1-OHP mass from
the calibration curve, (9) calculation of 1-OHP concentration in urine. The evaluation of the uncertainty is based on quantification
of individual components. Combined uncertainty was calculated using the law of propagation of uncertainties according to the
EURACHEM/CITAC guidelines. Level dependence of the uncertainty arises from the calibration curve.
The limits of detection and quantification were found to be equal to 0.03 and 0.1 ng/mL, respectively. The calculated expanded
level-dependent uncertainty covers 47–27–25% within the concentration range 0.03–0.1–0.4 ng/mL with the materials and equipment
used. These parameters could easily be recalculated according to the proposed scheme if there are some changes in the analysis
procedure. 相似文献
107.
Boris Pejin Kristina Tešanović Dragica Jakovljević Sonja Kaišarević Filip Šibul Milena Rašeta 《Natural product research》2019,33(5):750-754
The polysaccharide (PSH) extracts from the edible mushroom species Coprinus comatus and Coprinellus truncorum were screened in liquid for their acetylcholinesterase inhibitory (AChE) activity. Both extracts were found to display inhibition of the aforementioned enzyme reaching similar IC50 values of 0.62 ± 0.07 and 0.61 ± 0.03 mg/mL, respectively. According to the means of FTIR spectroscopy, these PSH extracts mostly contained β-glucans. However, the presence of some proteins and polyphenolics as minor ingredients were also detected. Compared with existing literature data for anti-AChE activity of the sugar samples, the findings within this study may be treated as a profound bioactivity. Consequently, this study puts some light on the possible use of the screened macrofungi in the palliative treatment of Alzheimer’s disease. 相似文献
108.
On the Harary index for the characterization of chemical graphs 总被引:1,自引:0,他引:1
109.
H. Langfelderová L'. Macášková K. Otrubová J. Gažo 《Journal of Thermal Analysis and Calorimetry》1986,31(5):1143-1151
The thermal decompositions of Cu(en)2(NCS)X. where X–=Cl–, Br–, NO
3
–
, BF
4
–
and ClO
4
–
, have been studied in comparison with the courses of Cu(en)2(SCN)2 and Cu(en)2X2 decomposition. It is shown that the presence of the thiocyanate group in the complexes Cu(en)2(NCS)X is the most important factor in the decomposition course, in agreement with the fact that the anions X– are not coordinated. or are only semicoordinated. Significant differences were found in the courses of thermal decomposition of two forms of Cu(en)2(NCS)(BF4) differing in the structure of their coordination polyhedra.
Zusammenfassung Die thermische Zersetzung von Cu(en)2(NCS)X (X=Cl Br, NO3, BF4 und ClO4) wurde untersucht und mit der von Cu(en2(SCN)2 und Cu(en)2X2 verglichem. Der den Verlauf der Zersetzung entscheidend bestimmende Faktor isi die Anw esenheit der Thiocyanat-Gruppe in den Cu(en)2(NCS)X-Komplexen, was in Übereinstimmung damit steht,. daß die Anionen X nicht oder nur teilweise koordiniert sind. Es wurden signifikante Unterschiedeim Verlauf der thermischen Zersetzung von zwei sich in der Struktur ihrer Kordinationspolyeder unter-, heidenden Formen von Cu(en)2(NCS)(BF4) gefunden.
Cu(en)2(NCS)X (X–=Cl–, Br–, NO 4 – , NO 3 – , BF4 ClO4, Cu(en)2(SCN)2 Cu(en)2(X)2. , Cu(en)2(NCS)X X Cu(en) (NCS)BF4 i .相似文献
110.
π-electron energies and bond orders of benzenoid hydrocarbons with up to five fused hexagons have been considered by the simple
Bond Orbital Resonance Theory (BORT) approach. The corresponding ground states were determined according to four BORT models.
In the first three models a diagonalisation of the Hückel-type Hamiltonian was performed in the bases of Kekulé, of Kekulé
and mono-Claus and of Kekulé and Claus resonance structures, respectively. In the fourth model a simple BORT ansatz was used.
According to this ansatz, the ground state is a linear combination of the positive Kekulé structures, all with equal coefficients.
It was shown that π-electron energies and bond orders obtained by these models correlate much better with the PPP energies
and bond orders than with the Hückel energies and bond orders. This indicates that a simple BORT approach is quite reliable
in predicting the more sophisticated PPP results. Concerning the relative performance of the four BORT models, the best results
were obtained with the BORT ansatz. The performance deteriorates with the expansion of the basis set. This is attributed to
the fact that in these models the improvement of the basis set is not accompanied with the corresponding improvement of the
Hamiltonian. Comparing the BORT-ansatz bond orders with the Pauling bond orders, it was shown that BORT-ansatz bond orders
correlate much better with the PPP bond orders.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献