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161.
Muhammad Ihsan Ul Haq 《Russian Journal of Applied Chemistry》2007,80(7):1256-1269
Unsaturated polyester resins containing long chain fatty acids and styrene as cross-linking agents are easily available in
Pakistan. I have made use of these resins in the preparation of overprint varnish, ornaments, synthetic marble and other related
substances. The octates of manganese, cobalt, calcium and lead along with peroxide were used for jelling and drying of the
resins. The effects of metal driers, aluminium stearate, peroxides and unsaturated long chain fatty acids in the composition
as mentioned in the experimental section were also studied. The merits and demerits developed in the end products resulting
from the variation of these chemicals in the compositions were also noted at their respective places.
The article was submitted by the author in English. 相似文献
162.
A series of 3-(p-X-phenyl) thiophene monomers (X= –H, –CH3, –OCH3, –COCH3, –COOC2H5, –NO2) was electrochemically polymerized to furnish polymer films that could be reversibly reduced and oxidized (n- and p-doped). The oxidation potentials of the monomers and formal potentials of the n- and p-doping processes of polymers were correlated with resonance and inductive effects of the substituents on the phenyl ring
as well as the semiempirically calculated heat of formation of the monomer radical cations.
Presented at the 4th Baltic Conference on Electrochemistry, Greifswald, March 13-16, 2005 相似文献
163.
M. Wasim A. Rahman S. Waheed M. Daud S. Ahmad 《Journal of Radioanalytical and Nuclear Chemistry》2003,255(2):397-402
Air particulate matter (PM) was collected in two size fractions using stacked filter units (SFUs) provided by the International Atomic Energy Agency (IAEA) from the industrial area of Islamabad. Nucleopore polycarbonate filters were used for collecting from Oct 98 to Jun 99 the particulate matter in coarse and fine size fractions. The samples were characterized by the instrumental neutron activation analysis (INAA). About 33 elements were quantified using different irradiation and counting protocols. 相似文献
164.
Khushbakht Sultan Muhammad Zakir Noor Ul Akber Murad Ali Khan 《Natural product research》2016,30(10):1202-1204
Eruca sativa Miller is a worldwide common alimentary plant (rocket leaves). The aim of this study was to correlate the potential in vitro scavenging activity of the E. sativa hydroalcoholic extract (HAE) with its in vivo hypoglycaemic effect. In DDPH free radical (DFR) and ferric-reducing antioxidant power assays, HAE in a concentration dependent manner (25–100 μg/mL) displayed a strong scavenging activity with maximum effect of 88% and 75% at 100 μg/mL, respectively. Daily administration of HAE (50 mg/kg; p.o.) in the in vivo model of alloxan-induced diabetic rabbits for 28 days showed significant reduction in glycaemia, also supported by recovery of body weight. In conclusion, our results give preliminary information on the potential use of this plant as a nutraceutical, useful to control and/or prevent a hyperglycaemic status. 相似文献
165.
The kinetics of solid Fe–Cr solution formation has been studied during mechanical alloying of Fe and Cr powders taken in an atomic ratio of 80: 20. X-ray diffraction and Mössbauer spectroscopy data have been analyzed within the framework of the energetic approach. It has been established that, in this system, reaction product yield N is related to mechanical energy dose D and specific surface area S of Fe nanograin boundaries in an ideal manner: N ~ D2 at S ~ D and N ~ D at S = const. 相似文献
166.
Dr. Monika M. Lindner Dr. M. Wasim Alachraf Benjamin Mitschke Dr. Philipp Schulze Dr. Markus Leutzsch Prof. Dr. Dr. h.c. Benjamin List 《Angewandte Chemie (International ed. in English)》2023,62(35):e202303119
Toward a conversion of aldehydes into arenes, we designed a sequence involving the initial reaction of an aldehyde to give a fulvene, followed by photochemical and platinum-catalyzed rearrangements into a Dewar benzene derivative, which finally isomerizes into the targeted arene. While computational studies support the plausibility of this route, we found that fulvene irradiation resulted in an unexpected isomerization into a spiro[2.4]heptadiene. This unusual photorearrangement has been investigated mechanistically and provides access to a variety of spiro[2.4]heptadienes with different substituents. 相似文献
167.
Saidkhodzha Nematulloev Dr. Arunachalam Sagadevan Badriah Alamer Dr. Aleksander Shkurenko Dr. Renwu Huang Dr. Jun Yin Dr. Chunwei Dong Dr. Peng Yuan Dr. Khursand E. Yorov Azimet A. Karluk Dr. Wasim J. Mir Bashir E. Hasanov Dr. Mohamed Nejib Hedhili Dr. Naveen M. Halappa Prof. Dr. Mohamed Eddaoudi Prof. Dr. Omar F. Mohammed Prof. Dr. Magnus Rueping Prof. Dr. Osman M. Bakr 《Angewandte Chemie (International ed. in English)》2023,62(26):e202303572
Point defects in nanoparticles have long been hypothesized to play an important role in governing the particle's electronic structure and physicochemical properties. However, single point defects in material systems usually exist with other heterogeneities, obscuring the chemical role of the effects. Herein, we report the synthesis of novel atomically precise, copper hydride nanoclusters (NCs), [Cu28H10(C7H7S)18(TPP)3] ( Cu28 ; TPP: triphenylphosphine; C7H7S: o-thiocresol) with a defined defect in the gram scale via a one-pot reduction method. The Cu28 acts as a highly selective catalyst for C−C cross-couplings. The work highlights the potential of defective NCs as model systems for investigating individual defects, correlating defects with physiochemical properties, and rationally designing new nanoparticle catalysts. 相似文献
168.
M. Wasim J. H. Zaidi M. Arif I. Fatima 《Journal of Radioanalytical and Nuclear Chemistry》2008,277(3):525-529
The k
0 method has been introduced at the 30 kW miniaturized neutron source reactor (MNSR) at the Pakistan Institute of Nuclear Science
& Technology (PINSTECH). It involved the full energy peak efficiency calibration of the HPGe detector for different counting
geometries and the characterization of the neutron flux at four inner irradiation channels. The latter involved the determination
of the thermal to the epithermal flux ratio, epithermal flux shape factor, the modified spectral index, Westcott’s g-factor,
the Maxwellian neutron temperature and the fast flux. The method was validated by analyzing IAEA-SL1 (Lake Sediment) and NIST-SRM-1572
(Citrus Leaves) reference materials. All calculations were performed in Excel, including the optimization step. The results
revealed that most of the elements were estimated with less than 10% relative deviation from the certified value. 相似文献
169.
Yu. A. Ferapontov M. A. Ul’yanova T. V. Sazhneva 《Russian Journal of Inorganic Chemistry》2008,53(10):1635-1640
The decomposition kinetics of peroxide products contained in the liquid phase of the LiOH-H2O2-H2O ternary system were studied, and the applicability of the solubility method to studying this system was demonstrated for hydrogen peroxide concentrations in the liquid phase from 2 to 6 wt % and temperatures of 21–33°C. The stabilizing influence of solid Li2O2 · H2O on hydrogen peroxide decomposition was demonstrated. The temperature and concentration boundaries of existence were determined for the Li2O2 · H2O phase, whose identity was verified by chemical analysis and qualitative X-ray powder diffraction analysis. 相似文献
170.
V. V. Voitylov A. V. Voitylov E. N. Korytkova V. P. Romanov S. V. Ul’yanov V. V. Gusarov 《Russian Journal of Applied Chemistry》2008,81(2):207-211
Behavior of hydrosilicate nanotubes of composition Mg3Si2O5(OH)4 in aqueous dispersions was studied. Experiments devoted to observation of steady-state and relaxation electro-optical effects demonstrated that, irrespective of their initial concentration in water, nanotubes form stable bulk aggregates with weak anisotropy, rather than a homogeneous system of separate suspended nanosize cylinders. 相似文献