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1.
Zr(SO3F)4, (A); ZrO(SO3F)2, (B); Zr(O2CCH3)2, (SO3F)2, (C); and Zr(O2CCH3)3SO3F, (D) have been prepared and characterized (elemental analysis,i.r. Spectra and thermal analysis). The SO3F groups are bidentate in (A) – (C) but have C3V symmetry in D where all the three oxygen atoms of SO3F group are coordinated in an equivalent manner. (A) – (D) are good Lewis acids and form coordination complexes with pyridine, triphenylphosphine oxide and 2,2′-bipyridyl. The thermal decomposition of the fluorosulphates is complex. 相似文献
2.
Detrimental Ni(0) transfer in Kumada catalyst transfer polycondensation of benzo[2,1‐b:3,4‐b']dithiophene 下载免费PDF全文
Anjan Bedi Julien De Winter Pascal Gerbaux Guy Koeckelberghs 《Journal of polymer science. Part A, Polymer chemistry》2016,54(12):1706-1712
This article deals with the Kumada Catalyst Transfer Polycondensation (KCTP) of 4,7‐dioctylbenzo[2,1‐b:3,4‐b']dithiophene ( BDP‐Oct ) using Ni(II) catalyst or In/cat combination. A combination of MALDI MS, GPC, and 31P NMR spectroscopy is used to reveal the failure of the KCTP of this particular monomer. Intermolecular transfer reactions to monomer appeared to prevent the formation of polymer. This result is remarkable, since isomeric benzo[1,2‐b:4,5‐b']dithiophene polymerizes in a controlled way. The presence of a “non‐aromatic double bond” in annulated monomers is discussed. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2016 , 54, 1706–1712 相似文献
3.
In the present communication a method based on the three body forces for the evaluation of second and third order elastic constants of mixed ammonium halides has been described. The Lundqvist three body potential is used along with long range Coulombian and short-range overlap repulsive potentials. The latter is taken of the Born-Mayer type and effective up to first neighbours only. It has been assumed that the charge transfer and short-range parameters depend linearly on the composition of solid solutions. Theoretical results obtained, for the entire range of compositions of mixed NH4Cl and NH4Br, have been compared with the recently measured experimental values and the theoretical results of other workers, whenever these are available.The authors are thankful to Dr. J. Shanker, Department of Physics, Agra University, Agra, for helpful discussions. 相似文献
4.
A variational principle is stated which describes the isothermal flow of a class of ideal incompressible materials, of which the ideal non-Newtonian liquid and the rigid-plastic von Mises solid are special cases. The principle is extended to multi-layered media separated by a prescribed interface. An inverse method is outlined for the determination of the common surface between two materials for flows parallel to a given plane. 相似文献
5.
Gupta S Pandotra P Ram G Anand R Gupta AP Husain K Bedi YS Mallavarapu GR 《Natural product communications》2011,6(1):93-96
The chemical composition of the essential oil from the rhizome of ginger (Zingiber officinale Roscoe), collected from Nahan, Himachal Pradesh, India, was determined by gas chromatography and GC-MS. Fifty-one compounds, representing 95.1% of the oil, were identified. The oil was characterized by relatively large amounts of the monoterpenoids 1,8-cineole (10.9%), linalool (4.8%), borneol (5.6%), alpha-terpineol (3.6%), neral (8.1%), geraniol (14.5%), geranial (9.5%), trans-dimethoxy citral (5.0%) and geranyl acetate (6.3%). Five compounds, namely trans-linalool oxide, trans-linalool oxide acetate, (Z)-dimethoxycitral, (E)-dimethoxy citral and epi-zingiberenol are reported for the first time in oil of ginger. 相似文献
6.
Chemical, Dehydration, Differential Thermal and X-ray analysis of some clays has been carried out to study their mineralogical composition. All the clay samples appear to be basically montmorillonites. While in one of the clays, montmorillonite is the predominent phase, the other two also contain illites besides other clay mineral impurities. 相似文献
7.
The quadrupole interaction (QI) in hexagonal close packed zinc lattice was measured using the 482 keV, 10.6 ns probe state of181Ta employing the time-differential perturbed angular correlation technique. The electric field gradient (EFG) at181Ta in Zn was derived from the measured quadrupole interaction frequency at room temperature asV
zz
=12.202×1017 V/cm2. The quadrupole interaction measured at various temperatures displayed normal temperature dependence similar to that seen by this probe in many non-cubic hosts. 相似文献
8.
LetR be a ring and σ an automorphism ofR. We prove the following results: (i)J(R
σ[x])={Σiri
x
i:r0∈I∩J(R]),
r
i∈I for alliε 1} whereI↪ {r∈R:rx ∈J(R
Σ[x])|s= (ii)J(R
σ<x>)=(J(R
σ<x>)∩R)σ<x>. As an application of the second result we prove that ifG is a solvable group such thatG andR, + have disjoint torsions thenJ(R)=0 impliesJ(R(G))=0. 相似文献
9.
Electrodiffusion of ions, both inside and outside biologicalcells, are of utmost importance to proper cellular functions.Experiments indicate that both ion concentrations and electropotentialcan jump discontinuously across the cell membranes. We studya system of nonlinear partial differential equations modellingsuch phenomena. Jump conditions for species concentrations andelectropotential across cell membranes are imposed. Under zero-fluxboundary conditions for one-dimensional domains, the solutionsare proved to exist for all times. With further assumptions,these transient solutions will converge to the unique steady-statesolution. Numerical experiments in one- and two-dimensionaldomains are also performed in order to study some unresolvedtheoretical issues. 相似文献
10.
N. Aggarwal B. Singh A. K. Bhati Renu Bala S. C. Bedi H. S. Hans 《Hyperfine Interactions》1983,13(1-3):271-274
Integral perturbed angular correlation technique has been used to measure the internal hyperfine magnetic fields at Hf nuclei in Fe, Co and Ni matrices. These represent a consistent set of measurements with diffused sources. The 9+/2 (208 keV) 9?/2 (113 keV) 7?/2 cascade in the decay of177Lu→177Hf was used for measurements. The results obtained are: $$\begin{gathered} H_{Fe}^{Hf} = - 266 \pm 47 kG, \hfill \\ H_{Co}^{Hf} = - 116 \pm 18 kG, \hfill \\ H_{Ni}^{Hf} = - 118 \pm 26 kG. \hfill \\ \end{gathered} $$ These measurements are compared with previous results and discussed in terms of methods of source preparation. 相似文献