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Calculation of multicentre nuclear attraction integrals over Slater-type orbitals using unsymmetrical one-range addition theorems 下载免费PDF全文
Using the unsymmetrical one-range addition theorems introduced by one of the authors with the help of complete orthonormal sets of Ψα-exponential type orbitals(α = 1,0,1,2,...),this paper presents the sets of series expansion relations for multicentre nuclear attraction integrals over Slater-type orbitals arising in Hartree-Fock-Roothaan equations for molecules.The final results are expressed through multicentre charge density expansion coefficients and basic integrals.The convergence of the series is tested by calculating concrete cases for arbitrary values of parameters of orbitals. 相似文献
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Polyamide-borax composites were prepared from solution of polyimide and the borax using N-methyl-2-pyrrolidone as a solvent. The Polyimide-borax composites films (PI-BX) characterized by FTIR, SEM and x-ray. The borax content significantly influences thermal behavior of the polymeric films, such as glass transition and decomposition temperatures of polyimide-borax composites. The glass transition temperatures of the composites were higher than that of the original polyimide. The flammability properties of them were demonstrated by cone calorimeter and indicate that the borax composites have significantly decreased in heat release rate, and mass loss rate. The PI-BX composites appears very good the flame retardant properties. 相似文献
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Yuhang Liu Seckin Akin Alexander Hinderhofer Felix T. Eickemeyer Hongwei Zhu Ji‐Youn Seo Jiahuan Zhang Frank Schreiber Hong Zhang Shaik M. Zakeeruddin Anders Hagfeldt M. Ibrahim Dar Michael Grtzel 《Angewandte Chemie (International ed. in English)》2020,59(36):15688-15694
As a result of their attractive optoelectronic properties, metal halide APbI3 perovskites employing formamidinium (FA+) as the A cation are the focus of research. The superior chemical and thermal stability of FA+ cations makes α‐FAPbI3 more suitable for solar‐cell applications than methylammonium lead iodide (MAPbI3). However, its spontaneous conversion into the yellow non‐perovskite phase (δ‐FAPbI3) under ambient conditions poses a serious challenge for practical applications. Herein, we report on the stabilization of the desired α‐FAPbI3 perovskite phase by protecting it with a two‐dimensional (2D) IBA2FAPb2I7 (IBA=iso‐butylammonium overlayer, formed via stepwise annealing. The α‐FAPbI3/IBA2FAPb2I7 based perovskite solar cell (PSC) reached a high power conversion efficiency (PCE) of close to 23 %. In addition, it showed excellent operational stability, retaining around 85 % of its initial efficiency under severe combined heat and light stress, that is, simultaneous exposure with maximum power tracking to full simulated sunlight at 80 °C over 500 h. 相似文献
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Seckin Erden Kingsley K. C. Ho Steven Lamoriniere Adam F. Lee Hasan Yildiz Alexander Bismarck 《Plasma Chemistry and Plasma Processing》2010,30(4):471-487
Continuous atmospheric plasma oxidation (APO) was used to introduce oxygen functionalities to the surface of carbon fibres
in an attempt to enhance interfacial adhesion between carbon fibres and polyamide-12 (PA-12). APO only affects the surface
properties of the fibres while their bulk properties remained unchanged. Contact angle and ζ-potential measurements demonstrated
that APO-treated fibres became significantly more hydrophilic due to the introduction of polar oxygen-containing groups on
the fibre surface, which also resulted in an increase of surface energy on the carbon fibres. The interfacial shear strength
of single carbon fibre/PA-12 model composites, determined by single fibre fragmentation tests, showed an increase from 40
to 83 MPa with up to 4 min of APO treatment time which confirms that the fibre/matrix interfacial adhesion was enhanced. This
highlights that the incorporation of APO into composite manufacturing will allow tailoring of the fibre/matrix interface. 相似文献
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We present a general, systematic, and efficient method for decomposing any given exponential operator of bosonic mode operators, describing an arbitrary multimode Hamiltonian evolution, into a set of universal unitary gates. Although our approach is mainly oriented towards continuous-variable quantum computation, it may be used more generally whenever quantum states are to be transformed deterministically, e.g., in quantum control, discrete-variable quantum computation, or Hamiltonian simulation. We illustrate our scheme by presenting decompositions for various nonlinear Hamiltonians including quartic Kerr interactions. Finally, we conclude with two potential experiments utilizing offline-prepared optical cubic states and homodyne detections, in which quantum information is processed optically or in an atomic memory using quadratic light-atom interactions. 相似文献
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Dr. Yuhang Liu Dr. Seckin Akin Dr. Alexander Hinderhofer Dr. Felix T. Eickemeyer Hongwei Zhu Dr. Ji-Youn Seo Jiahuan Zhang Prof. Frank Schreiber Dr. Hong Zhang Dr. Shaik M. Zakeeruddin Prof. Anders Hagfeldt Dr. M. Ibrahim Dar Prof. Michael Grätzel 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(36):15818-15824
As a result of their attractive optoelectronic properties, metal halide APbI3 perovskites employing formamidinium (FA+) as the A cation are the focus of research. The superior chemical and thermal stability of FA+ cations makes α-FAPbI3 more suitable for solar-cell applications than methylammonium lead iodide (MAPbI3). However, its spontaneous conversion into the yellow non-perovskite phase (δ-FAPbI3) under ambient conditions poses a serious challenge for practical applications. Herein, we report on the stabilization of the desired α-FAPbI3 perovskite phase by protecting it with a two-dimensional (2D) IBA2FAPb2I7 (IBA=iso-butylammonium overlayer, formed via stepwise annealing. The α-FAPbI3/IBA2FAPb2I7 based perovskite solar cell (PSC) reached a high power conversion efficiency (PCE) of close to 23 %. In addition, it showed excellent operational stability, retaining around 85 % of its initial efficiency under severe combined heat and light stress, that is, simultaneous exposure with maximum power tracking to full simulated sunlight at 80 °C over 500 h. 相似文献
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Niss K Begen B Frick B Ollivier J Beraud A Sokolov A Novikov VN Alba-Simionesco C 《Physical review letters》2007,99(5):055502
We study the changes in the low-frequency vibrational dynamics of poly(isobutylene) under pressure up to 1.4 GPa, corresponding to a density change of 20%. Combining inelastic neutron, x-ray, and Brillouin light scattering, we analyze the variations in the boson peak, transverse and longitudinal sound velocities, and the Debye level under pressure. We find that the boson peak variation under pressure cannot be explained by the elastic continuum transformation only. Surprisingly, the shape of the boson peak remains unchanged even at such high compression. 相似文献
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Dr. Sara Vidal Dr. Marta Izquierdo Dr. Salvatore Filippone Dr. Israel Fernández Seckin Akin Dr. Ji-Youn Seo Dr. Shaik M. Zakeeruddin Prof. Michael Grätzel Prof. Nazario Martín 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(13):3224-3228
We report on the site-selective synthesis of PCBM-like [70]fullerene site-isomers, where the elusive β-site-isomers are, for the first time, the major product in a (cyclo)addition chemical reaction involving [70]fullerene. The reaction involves an straightforward cyclopropanation of [70]fullerene from sulfonium salts, affording a mixture of α and β site-isomers in good yields. Amazingly, the preference for the α- or β-site-isomer can be efficiently controlled by means of the solvent polarity! DFT theoretical calculations (DMF and toluene) nicely predict that, although the formation of the α-adduct is, as expected, thermodynamically favored, the selectivity of the process is determined by the energy difference of the respective transition states. Furthermore, the employ of α or/and β site-isomers, as pure materials or as a mixture of them, used as templating agent, has been evaluated in perovskite solar cells. The positive influence of the [70]fullerenes by passivating the voids/pin-holes and/or deep slits, is reflected in highly efficient and stable bulk heterojunction perovskite solar cells, whose performance (around 20 %) is slightly but consistently depending on the isomeric fullerene composition. These experimental findings pave the way to investigate a new reactivity on C70 and to explore the properties of the less-known β-derivatives. 相似文献
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