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191.
Miriam Karni Yitzhak Apeloig Detlef Schrder Waltraud Zummack Roberto Rabezzana Helmut Schwarz 《Angewandte Chemie (International ed. in English)》1999,38(3):331-335
Neutralization of [C,H,Si,X] radical cations (X=F, Cl) in conjunction with electronic structure calculations provides the first experimental evidence for the formation of the neutral silynes HC≡SiF and HC≡SiCl, which have nonlinear structures (see picture). 相似文献
192.
193.
Andrea Turonová Miriam Gálová Ladislav Lux Miroslav Gál 《Journal of Solid State Electrochemistry》2001,5(7-8):502-506
Ni electrodeposition on Fe powder was studied with respect to an inhibiting adsorbed hydroxycomplex layer. Its elimination
was done in three possible ways: by increasing the rotation speed of the circular stirring of the suspension, by chemical
dissolution of the adsorbed layer during interrupted electrolysis, and by addition of a complexing agent – sodium citrate
into the electrolyte. The simultaneous deposition of a Cu/Ni coating was enabled by proper electrolyte composition as to the
ratio of both metallic compounds and by the addition of a suitable complexing agent. The Cu/Ni ratio was influenced, beside
electrochemical parameters, also by the particle size of the Fe powder and by the suspension density. Increasing the suspension
density supports the deposition of Ni, and increasing the particle size supportsthe deposition of Cu.
Electronic Publication 相似文献
194.
FabioMarchetti Claudio Pettinari Augusto Cingolani Lauro Brocanelli Miriam Rossi Francesco Caruso 《Journal of organometallic chemistry》1999,580(2):98
The synthesis of three 1-(4-trifluoromethylphenyl)-3-methyl-4-R1(C=O)-5-pyrazolone proligands LH (L1H; R1=C6H5: L2H; R1=CH3: L3H; R1=CF3) and their interaction with R3Sn(IV) acceptors (R=Me, Bun, Ph) are reported. When R=Me or Bun, aquo (4-acylpyrazolonate)SnR3(H2O) derivatives are obtained and the anionic donors 4-acylpyrazolonate (L−) act in the O–monodentate form. These triorganotin complexes are not stable in chlorohydrocarbon solvents and decompose to R4Sn and bis(4-acyl-5-pyrazolonate)2SnR2. When R=Ph, stable (4-acyl-5-pyrazolonate)SnPh3 derivatives, both in solution and in the solid state, are obtained. The crystal structure of (1-(4-trifluoromethylphenyl)-3-methyl-4-acetylpyrazolon-5-ato)triphenyltin(IV) shows a five-coordinate tin atom in a strongly distorted cis-bipyramidal trigonal environment (axial angle=161.2(2)°) with the acylpyrazolonate donor acting as an asymmetric O2–bidentate species (Sn–O(1)=2.081(6) Å: Sn–O(2)=2.424(5) Å). Electronic effects are responsible for the different behavior shown by these trialkyl and triphenyl derivatives. 相似文献
195.
Ladislav Lux Miriam Gálová Mária Heželová Kveta Markušová 《Journal of Solid State Electrochemistry》1999,3(5):288-292
The ability of abrasive voltammetry to reflect the reactivity of iron powder immobilized on paraffin-impregnated graphite
electrodes was investigated. Normal pulse voltammetry was used as the preferred method. The peak shape and position on the
potential/time axis reflected both the reactivity of iron powder particles as well as their size fraction. “Relative peak
height” defined as peak height to area ratio, i.e., current to charge ratio, correlated well with the rate of the electrochemical
dissolution process. It showed not only a decreasing dissolution rate with an increase in particle size, but also the differencies
in the dissolution rate of iron powder of various reactive surfaces as a consequence of various pretreatment methods. It was
found that chemical pretreatment of the powder always resulted in a faster dissolution process in comparison with other non-chemical
pretreatment methods.
Received: 30 June 1998 / Accepted: 30 September 1998 相似文献
196.
197.
A novel high-speed infrared modulator is proposed which uses resonant tunneling and intersubband optical transitions within the conduction band of a semiconductor quantum well. Variations of the applied bias voltage control the amount of light transmitted through the device. 相似文献
198.
Juan Pedro Rojas-Armas Jorge Luis Arroyo-Acevedo Miriam Palomino-Pacheco Jos Manuel Ortiz-Snchez James Calva Hugo Jesus Justil-Guerrero Americo Castro-Luna Norma Ramos-Cevallos Edwin Csar Cieza-Macedo Oscar Herrera-Calderon 《Molecules (Basel, Switzerland)》2022,27(6)
Annona muricata leaves are traditionally used as an anticancer plant in the world. The aim of this study was to evaluate the ameliorative effect of the essential oil from Annona muricata leaves (EOAm) in an experimental model of breast cancer and to determine the volatile constituents with gas chromatography-mass spectrometry (GC-MS). Thirty female rats were assigned to five groups: the control group; the DMBA (7,12-dimethylbenz[α]anthracene) group; and three groups received daily EOAm doses of 50, 100, and 200 mg/kg/day, plus DMBA, respectively. After 13 weeks of treatment, tumors were analyzed pathologically and biochemical markers in serum were noted. As a result, in GC-MS analysis, 40 compounds were identified and 4 of them were abundant: Z-caryophyllene (40.22%), followed by α-selinene (9.94%), β-pinene (8.92%), and β-elemene (7.48%). Furthermore, EOAm in a dose-dependent form produced a reduction in tumor frequency and the accumulated tumor volume was reduced by 50% and 71% with doses of 100 and 200 mg/kg, respectively. Serum levels of reduced glutathione (GSH) increased and malondialdehyde (MDA) decreased significantly compared to the DMBA group. Serum levels of vascular endothelial growth factor (VEGF) decreased significantly from 70.75 ± 7.15 pg/mL in the DMBA group to 46.50 ± 9.00 and 34.13 ± 11.50 pg/mL in groups treated with doses of 100 and 200 mg/kg, respectively. This study concludes that the EOAm leaves showed an ameliorative effect in a murine model of breast cancer. 相似文献
199.
Vanina Costamagna Miriam Strumia Mar Lpez‐Gonzlez Evaristo Riande 《Journal of Polymer Science.Polymer Physics》2006,44(19):2828-2840
The modification of polyethylene by the grafting of poly(acrylic acid) onto the surface of one of the faces of low‐density polyethylene films with UV radiation is reported. The transport of oxygen, nitrogen, carbon monoxide, carbon dioxide, methane, ethane, ethylene, propane, and argon across surface‐modified films containing 3.7% poly(acrylic acid) has been investigated at several temperatures. The layer of poly(acrylic acid) grafted onto the surface of one of the faces of the films reduces the permeability coefficient of the gases by a factor of about 1/6. The sharp drop in the gas permeability as a result of the poly(acrylic acid) layer may arise either from the formation of ordered structures of the grafted chains or from the development of highly crosslinked structures. The values of the polymer–gas enthalpic interaction parameter for the modified film are higher than those for the unmodified one. © 2006 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 44: 2828–2840, 2006 相似文献
200.