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31.
D. B. Parihar Om Prakash Indira Bajaj R. P. Tripathi K. K. Verma 《Mikrochimica acta》1971,59(3):393-398
Summary High explosives having the sameR
f
values on a thin-layer chromatogram and difficult to separate are readily resolved as their coloured -complexes with aromatic amines. After liberation from their complexes on the plate, up to 1.5 g of the explosives can be conveniently estimated at their characteristic absorption maxima.
Zusammenfassung Hochexplosive Substanzen mit gleichenR f -Werten auf Dünnschichtchromatogrammen, die sich schlecht trennen lassen, werden als gefärbte -Komplexe mit aromatischen Aminen gut voneinander getrennt. Nach Freisetzung aus den Komplexen auf der Platte können bis zu 1,5 g der Explosivstoffe bei ihrem charakteristischen Absorptionsmaximum auf übliche Weise bestimmt werden.相似文献
32.
Wave propagation in a rarefied two-component plasma immersed in a uniform constant magnetic field has been discussed wherein the plasma pressure is assumed to be anisotropic owing to finite Larmor radius effect. It is shown that, for propagation along the external magnetic field, there exist two modes of wave propagation, namely, the gravitational mode and the hydromagnetic mode. The former is found to be independent of the magnetic field and hence of the Larmor radius, while the latter is appreciably influenced by the finite Larmor radius. On the other hand, for transverse propagation, there are three modes of wave propagation viz. the ion-sound mode, the electron-sound mode and the electromagnetic mode. It is shown that only the lowfrequency ion-sound mode is affected by the finite Larmor radius. 相似文献
33.
D.C. Reynolds K.K. Bajaj G. Peters C. Leak W.M. Theis P.W. Yu H. Morkoc K. Alavi C. Colvard I. Shidlovsky 《Superlattices and Microstructures》1988,4(6)
Sharp-line structure associated with both the light-hole free exciton (LHFE) and heavy-hole free exciton (HHFE) transitions has been observed in multi-quantum-well (MQW) structures of four well sizes in photoluminescence (PL) and reflection spectra. These spectra have been deconvulated using photoluminescence excitation spectroscopy (PLE). The LHFE and HHFE sharp-line structure is associated with interface structure composed of growth islands at the interface between the barriers and the wells. Estimates of the average interface island sizes for the four different MQW structures are made based on theoretical modelling. A correlation is established between particular LHFE fine structure components and specific HHFE fine structure components. A model is developed to account for the LHFE and HHFE fine structure based on a non-random distribution of the interface structure. The physical location of the excitons is demonstrated to be in regions of the wells with essentially identical interfacial microstructure. Evidence for diffusion of excitons from effectively narrow well regions to wider well regions is presented. 相似文献
34.
Tekade Pradip V. Tale Bhagyashri U. Bajaj Sonal D. Authankar Nandini 《Russian Journal of Physical Chemistry A, Focus on Chemistry》2018,92(12):2488-2496
Russian Journal of Physical Chemistry A - Ultrasonic studies of compounds of dihydropyridine series in polar and non-polar solvents at various concentrations and temperatures 303–318 K.... 相似文献
35.
Tekade Pradip V. Bajaj Sonal Tale Bhagyashri Titirmare Neha R. Bandwal Priyanka 《Russian Journal of Physical Chemistry A, Focus on Chemistry》2018,92(12):2596-2599
Russian Journal of Physical Chemistry A - Formation of complexes Sr(II), Cr(II), and Al(III) with ligands (1,3-dioxo-1,3-dihydro-2H-isoindol-2-yl)acetic acid (L1),... 相似文献
36.
EP Sheretov VS Gurov MV Dubkov OV Korneeva 《Rapid communications in mass spectrometry : RCM》1999,13(16):1699-1702
In this article we compare the classical monopole mass filter of von Zahn and the monopole mass filter with a hyperbolic V-shaped electrode. The experimental results and those of computer simulation for both mass spectrometers are presented. We show that the replacement of a conventional 90 degrees V-shaped electrode by an electrode with a hyperbolic profile substantially improves the peak shape of any given mass, and increases the mass resolution by a factor of 3-4 and the abundance sensitivity by a factor of 100. The potential of high analytical performance combined with electroforming techniques for electrode manufacture indicate future practical uses of such instruments. Copyright 1999 John Wiley & Sons, Ltd. 相似文献
37.
Biocatalytic Synthesis of Allylic and Allenyl Sulfides through a Myoglobin‐Catalyzed Doyle–Kirmse Reaction 下载免费PDF全文
Dr. Vikas Tyagi Dr. Gopeekrishnan Sreenilayam Dr. Priyanka Bajaj Antonio Tinoco Prof. Dr. Rudi Fasan 《Angewandte Chemie (International ed. in English)》2016,55(43):13562-13566
The first example of a biocatalytic [2,3]‐sigmatropic rearrangement reaction involving allylic sulfides and diazo reagents (Doyle–Kirmse reaction) is reported. Engineered variants of sperm whale myoglobin catalyze this synthetically valuable C?C bond‐forming transformation with high efficiency and product conversions across a variety of sulfide substrates (e.g., aryl‐, benzyl‐, and alkyl‐substituted allylic sulfides) and α‐diazo esters. Moreover, the scope of this myoglobin‐mediated transformation could be extended to the conversion of propargylic sulfides to give substituted allenes. Active‐site mutations proved effective in enhancing the catalytic efficiency of the hemoprotein in these reactions as well as modulating the enantioselectivity, resulting in the identification of the myoglobin variant Mb(L29S,H64V,V68F), which is capable of mediating asymmetric Doyle–Kirmse reactions with an enantiomeric excess up to 71 %. This work extends the toolbox of currently available biocatalytic strategies for the asymmetric formation of carbon–carbon bonds. 相似文献
38.
Hornstein MK Bajaj VS Griffin RG Temkin RJ 《IEEE transactions on plasma science. IEEE Nuclear and Plasma Sciences Society》2006,34(3):524-533
We report the regulated continuous-wave (CW) operation of a second harmonic gyrotron oscillator at output power levels of over 8 W (12.4 kV and 135 mA beam voltage and current) in the TE(0,6,1) mode near 460 GHz. The gyrotron also operates in the second harmonic TE(2,6,1) mode at 456 GHz and in the TE(2,3,1) fundamental mode at 233 GHz. CW operation was demonstrated for a one-hour period in the TE(0,6,1) mode with better than 1% power stability, where the power was regulated using feedback control. Nonlinear simulations of the gyrotron operation agree with the experimentally measured output power and radio-frequency (RF) efficiency when cavity ohmic losses are included in the analysis. The output radiation pattern was measured using a pyroelectric camera and is highly Gaussian, with an ellipticity of 4%. The 460-GHz gyrotron will serve as a millimeter-wave source for sensitivity-enhanced nuclear magnetic resonance (dynamic nuclear polarization) experiments at a magnetic field of 16.4 T. 相似文献
39.
P. Bajaj R. C. Mehrotra
J. -C. Maire
R. Ouaki 《Journal of organometallic chemistry》1972,40(2):301-309Phenyl glycidyl ether and allyl glycidyl ether (3-phenoxy- and 3-allyloxy-1,2-epoxypropane) cause fission of the silicon---chlorine bonds in a number of alkylchlorosilanes to form chloro-substituted alkoxysilanes. Relative reactivities of cyclic ethers with chlorosilanes have been discussed. Structures of the adducts are suggested on the basis of their IR and proton magnetic resonance spectra. 相似文献
40.
The discovery of neutron rich isotopes of the lightest elements on the neutron drip line exhibiting a halo structure has opened
up new vistas in research activities. The novel structural features associated with the halo phenomena have been the subject
for extensive theoretical and experimental investigations in recent times. In this talk, I propose to present a broad overview
of the recent developments in this field, bringing out the striking features which show that a large number oflight nuclei
near the neutron drip line are characterized by a clear separation between a ‘normal’ core nucleus and a loosely bound low
density veil of neutrons. Specifically, the two neutron halos offer a natural premises, from a theoretical standpoint, to
employ three body techniques for studying their detailed structural properties. A considerable part of the talk will be devoted
to report and highlight the results on a number of light halo nuclei such as 11Li, 11Be, 19B and 22C on which we have been carrying out investigations employing a simple but realistic three body model. These three body systems
which have been termed as ‘Borromean’ (i.e while three body systems are bound, the corresponding binary subsystems on the
other hand are unbound) are characterized by large spacial extension and very low separation energy of the neutron. They are,
therefore, ideally suited for exploring the possibility of the existence of Efimov states in two neutron halo nuclei. We have
recently carried out the three body analyses to predict the possibility of the occurrence of such states on which experimental
work at various laboratories is underway. 相似文献