排序方式: 共有35条查询结果,搜索用时 31 毫秒
1.
A straightforward and effective procedure for the conversion of benzylic, allylic and aliphatic alcohols to the corresponding iodides using Ph3P/I2 under solvent-free conditions using microwave irradiation is reported. 相似文献
2.
3.
Non‐relativistic continuous states in arbitrary dimension for a ring‐shaped pseudo‐Coulomb and energy‐dependent potentials
下载免费PDF全文
![点击此处可从《Mathematical Methods in the Applied Sciences》网站下载免费的PDF全文](/ch/ext_images/free.gif)
In this research, the non‐relativistic particle scattering has been investigated for an alternative pseudo‐Coulomb potential plus ring‐shaped and an energy‐dependent potentials in D‐dimensional space. The normalized wave functions of continuous states on the k/2π scale are expressed in terms of the hyper‐geometric series, and formula of phase shifts is presented. Analytical properties of the scattering amplitude and thermodynamics properties are discussed. Some of the numerical results of energy levels have been calculated too. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
4.
In this research we analyzed the processes of J/ψ → ?f0(980) decay by calculating of three amplitude contributions as the electromagnetic (EM) contribution, short-distance (SD) contribution from the \(c\bar c\) annihilation at the wave function origin, and long-distance (LD) contribution from the open charm effects. We obtained the values of these contributions and calculated the branching ratio of this decay. 相似文献
5.
Eigen-spectra in the Dirac-attractive radial problem plus a tensor interaction under pseudospin and spin symmetry with the SUSY approach
下载免费PDF全文
![点击此处可从《中国物理 B》网站下载免费的PDF全文](/ch/ext_images/free.gif)
We approximately solve the Dirac equation for attractive radial potential including a Coulomb-like tensor interaction under pseudospin and the spin symmetry limit for any arbitrary spin-orbit quantum number, by employing the supersymmetric (SUSY) quantum mechanics and supersymmetric shape invariance technique. We obtain the energy eigenvalue equation under the pseudospin and spin conditions. Some numerical results are compared with those obtained by the Nikiforove-Uvarov (NU) method. 相似文献
6.
7.
We investigate the effects of final state interactions (FSI) contributions in the nonleptonic two body $B^ + \to D_S^ + \bar K^0$ decay, however the hadronic decay of $B^ + \to D_S^ + \bar K^0$ is analyzed by using “QCD factorization” (QCDF) method and final state interaction (FSI). First, the $B^ + \to D_S^ + \bar K^0$ decay is calculated via QCDF method and only the annihilation graphs exist in that method. Hence, the FSI must be seriously considered to solve the $B^ + \to D_S^ + \bar K^0$ decay and the D 0π+(D 0*ρ+), D +π0(D +*ρ0) and D +η c (D +*J/ψ) via the exchange of K +(*), K 0(*) and D s +(*) mesones are chosen for the intermediate states. To estimate the intermediate states amplitudes, the QCDF method is again used. These amplitudes are used in the absorptive part of the diagrams. The experimental branching ratio of $B^ + \to D_S^ + \bar K^0$ decay is less than 8 × 10?4 and the predicted branching ratio is 0.23 × 10?9 in the absence of FSI effects and it becomes 6.74 × 10?4 when FSI contributions are taken into account. 相似文献
8.
The zeta potential of PMMA in contact with electrolytes of various conditions: Theoretical and experimental investigation
下载免费PDF全文
![点击此处可从《Electrophoresis》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Hamid Falahati Lambert Wong Leila Davarpanah Abhinandan Garg Peter Schmitz Dominik P. J. Barz 《Electrophoresis》2014,35(6):870-882
Many unit operations required in microfluidics can be realised by electrokinetic phenomena. Electrokinetic phenomena are related to the presence of electrical surface charges of microfluidic substrates in contact with a liquid. As surface charges cannot be directly measured, the zeta potential is considered as the relevant parameter instead. PMMA is an attractive microfluidic substrate since micron‐sized features can be manufactured at low costs. However, the existence of PMMA surface charges is not well understood and the zeta potential data found in the literature show significant disagreement. In this article, we present a thorough investigation on the zeta potential of PMMA. We use computations of the potential distribution in the electrical double layer to predict the influence of various electrolyte parameters. The generated knowledge is compared to extensive experiments where we investigate the influence of ionic strength, pH, temperature and the nature of the electrolyte. Our findings imply that two different mechanisms influence the zeta potential depending on the pH value. We propose pure shielding in the acidic and neutral milieus while adsorption of co‐ions occurs along with shielding in the alkaline milieu. 相似文献
9.
Frank Meyer‐Wegner Josef H. Wender Konstantin Falahati Timo Porsch Tanja Sinke Dr. Michael Bolte Prof. Dr. Matthias Wagner Prof. Dr. Max C. Holthausen Dr. Hans‐Wolfram Lerner 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(16):4681-4690
The reaction of 4‐chloro‐1,2‐dimethyl‐4‐supersilylsila‐1‐cyclopentene ( 2 a ) with Li[NiPr2] at ?78 °C results in the formation of the formal 1,4‐addition product of the silacyclopentadiene derivative 3,4‐dimethyl‐1‐supersilylsila‐1,3‐cyclopentadiene ( 4 a ) with 2,3‐dimethyl‐4‐supersilylsila‐1,3‐cyclopentadiene ( 5 a ). In addition the respective adducts of the Diels–Alder reactions of 4 a + 4 a and 4 a + 5 a were obtained. Compound 4 a , which displays an s‐cis‐silacyclopentadiene configuration, reacts with cyclohexene to form the racemate of the [4+2] cycloadduct of 4 a and cyclohexene ( 9 ). In the reaction between 4 a and 2,3‐dimethylbutadiene, however, 4 a acted as silene as well as silacyclopentadiene to yield the [2+4] and [4+2] cycloadducts 10 and 11 , respectively. The constitutions of 9 , 10 , and 11 were confirmed by NMR spectroscopy and their crystal structures were determined. Reaction of 4‐chloro‐1,2‐dimethyl‐4‐tert‐butyl‐4‐silacyclopent‐1‐ene ( 2 c ) with KC8 yielded the corresponding disilane ( 12 ), which was characterized by X‐ray crystal structure analysis (triclinic, P$\bar 1$ ). DFT calculations are used to unveil the mechanistic scenario underlying the observed reactivity. 相似文献
10.
Effects of Final State Interactions in Pure Annihilation Decay of B^{0}_{s}\rightarrow\pi^{0}\pi^{0}
Behnam Mohammadi Hossein Mehraban 《International Journal of Theoretical Physics》2013,52(7):2363-2378
We investigate the effects of final state interactions (FSI) contributions in the nonleptonic two body $B^{0}_{s} \rightarrow \pi^{0}\pi^{0}$ decay. The short distance interaction amplitude is calculated by using the annihilation diagrams and a tiny branching ratio is obtained, then the long distance amplitude is considered and calculated within FSI effects. For contributions of FSI, the ρ 0 ρ 0, π + π ?(ρ + ρ ?), K + K ?(K +? K ??) and $K^{0}\bar{K}^{0}(K^{0*}\bar{K}^{0*})$ are produced for intermediate states, in this case the π 0, π ?(ρ ?), K ?(?) and $\bar{K}^{0(*)}$ mesons are exchanged. The absorptive part of the diagrams is directly calculated and the dispersive part of the rescattering amplitude can be obtained from the absorptive part via the dispersion relation. The imaginary and real parts of the amplitudes are summed over all intermediate states. The predicted branching ratio of $B^{0}_{s} \rightarrow \pi^{0}\pi^{0}$ is 0.69×10?8 in the absence of FSI effects and it becomes 1.86×10?4 when FSI contributions are taken into account, while the experimental result is less than 2.1×10?4. 相似文献