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21.
The after effects of β− -decay on time differential perturbed angular correlation (TDPAC) spectra of II–VI semiconductor CdS have been studied using
β− -emitting111Ag as well as111mCd as probe nuclei. The TDPAC spectrum of111Ag in CdS exhibits a time dependent interaction indicating that the preceding β− -decay leaves the daughter nucleus in an excited state. The recovery time (τg) of the probe atom was found to be 16±6 ns while Abragam and Pound's relaxation time (τkr) was found to be 9±2 ns. The results show that β− -decay does change the chemical environment around the probe atom. 相似文献
22.
A new free recoverable and reusable mono-alkaloid-type ligand has been synthesized by a simple method.With highly polar groups,the ligand can be recycled and reused eight times to prepare ethyl(2R,3S)-2,3-dihydroxy-3-phenylpropionate with high yield and ee via asymmetric dihydroxylation(AD) reaction. 相似文献
23.
The concept of strong elements in posets is introduced. Several properties of
strong elements in different types of posets are studied. Strong posets are characterized in
terms of forbidden structures. It is shown that many of the classical results of lattice theory
can be extended to posets. In particular, we give several characterizations of strongness
for upper semimodular (USM) posets of finite length. We characterize modular pairs in
USM posets of finite length and we investigate the interrelationships between consistence,
strongness, and the property of being balanced in USM posets of finite length. In contrast
to the situation in upper semimodular lattices, we show that these three concepts do not
coincide in USM posets. 相似文献
24.
The concept of `adjunct' operation of two lattices with respect to a pair of elements is introduced. A structure theorem namely,
`A finite lattice is dismantlable if and only if it is an adjunct of chains' is obtained. Further it is established that for
any adjunct representation of a dismantlable lattice the number of chains as well as the number of times a pair of elements
occurs remains the same. If a dismantlable lattice L has n elements and n+k edges then it is proved that the number of irreducible elements of L lies between n-2k-2 and n-2. These results are used to enumerate the class of lattices with exactly two reducible elements, the class of lattices with
n elements and upto n+1 edges, and their subclasses of distributive lattices and modular lattices.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
25.
Ilija Najdovski Dr. PR Selvakannan Dr. Anthony P. O'Mullane Prof. Suresh K. Bhargava 《Chemistry (Weinheim an der Bergstrasse, Germany)》2011,17(36):10058-10063
A rapid electrochemical method based on using a clean hydrogen‐bubble template to form a bimetallic porous honeycomb Cu/Pd structure has been investigated. The addition of palladium salt to a copper‐plating bath under conditions of vigorous hydrogen evolution was found to influence the pore size and bulk concentration of copper and palladium in the honeycomb bimetallic structure. The surface was characterised by X‐ray photoelectron spectroscopy, which revealed that the surface of honeycomb Cu/Pd was found to be rich with a Cu/Pd alloy. The inclusion of palladium in the bimetallic structure not only influenced the pore size, but also modified the dendritic nature of the internal wall structure of the parent copper material into small nanometre‐sized crystallites. The chemical composition of the bimetallic structure and substantial morphology changes were found to significantly influence the surface‐enhanced Raman spectroscopic response for immobilised rhodamine B and the hydrogen‐evolution reaction. The ability to create free‐standing films of this honeycomb material may also have many advantages in the areas of gas‐ and liquid‐phase heterogeneous catalysis. 相似文献
26.
B. S. Shivashankar H. Naik S. V. Suryanarayana P. M. Prajapati V. K. Mulik K. C. Jagadeesan S. V. Thakare A. Goswami S. Ganesan 《Journal of Radioanalytical and Nuclear Chemistry》2012,292(2):745-750
The reaction cross-sections for 64Ni(n, γ) 65Ni at E
n
= 0.025 eV and 58Ni (n, p) 58Co at E
n
= 3.7 MeV have been experimentally determined using activation and off-line γ-ray spectrometric technique. The thermal neutron
flux used is from the thermal Column of the reactor APSARA at BARC, Mumbai, whereas the neutron energy of 3.7 MeV is from
the 7Li(p, n) reaction at Pelletron facility, TIFR, Mumbai. The 64Ni(n, γ) 65Ni and 58Ni(n, p) 58Co reactions cross-sections from present work are compared with the available literature data and found to be in good agreement.
The 58Ni(n, p) 58Co reaction as a function of neutron energy is also calculated theoretically using TALYS computer code version 1.2 and found
to be higher than the experimental data. 相似文献
27.
Milind S. Thakare Nilesh S. Pawar Vishnu A. Adole Dipak B. Patil Vikas Patil 《印度化学会志》2022,99(10):100670
A novel strategy, involving anchoring and un-anchoring of coumarin based fluorophore, has been established for the selective detection of Au3+ species. Selective sensing of Gold (Au3+) was triggered due to alkynophilicity of gold ions to create lateral fluorescence of a latent fluorophore. The 4-methyl-2-oxo-2H-chromen-7-yl 2-(2-phenylethynyl) benzoate (CEB) probe was synthesized by reacting 7-hydroxy-4-methylcoumarin with iodo-benzoic acid. CEB probe has an absorption at 300 nm and 335 nm which decreases gradually and new absorption appeared at 406 nm due to Au3+ promoted ester hydrolysis selectively over other metal ions with great sensitivity, which accompanies a turn on fluorescence change produced by 7-hydroxy coumarin. The principle behind this sensing strategy is activation of triple bond induced uniquely by Au+3 ions leading to cascade and delivers active fluorophore. The sensing mechanism was proposed and supported by 1H NMR, MS and TD-DFT experiments. The density functional theory (DFT) and time dependent density functional theory (TD-DFT) theoretical results of the CEB-probe and Au3+ reaction is in good agreement with the experimental results. Additionally, probe could be well incorporated onto the test strips for effective detection of Au3+. 相似文献
28.
S. F. Patil Nilima S. Rajurkar A. T. Thakare 《Journal of Radioanalytical and Nuclear Chemistry》1986,106(4):233-241
The concentration dependence of experimental diffusion coefficients of cobalt ions in presence of some alkali metal chlorides is examined in the light of the Onsager theory. The diffusion coefficients are measured in 1% agar gel using the zone-diffusion technique. The positive and negative deviations observed at higher and lower concentrations, respectively, are explained in terms of relative contributions of various types of effects occurring in the diffusion medium. 相似文献
29.
30.
The pm-lattices are the bounded distributive lattices in which every prime ideal is contained in a unique maximal ideal. In
pm-lattices the map which sends every prime ideal into the unique maximal ideal containing it, is shown to be continuous;
and this map is the unique retraction of the prime spectrum onto the maximal spectrum. Further we show that the pm-property
is equivalent to the normality of the prime spectrum and it implies that the maximal spectrum isT
2.
Presented by A. Horn.
The first named author gratefully acknowledges the financial assistance in the form of U.G.C.Jr. Research Fellowship. 相似文献