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1.
[Cl3PNPCl3][MoNCl4], a Compound having Columns of Stacked Anions The title compound is formed by the reaction of [Cl3PNPCl3]Cl with MoNCl3 in CH2Cl2 and subsequent precipitation with CCl4 in from of orange-red crystals. According to the 31P-NMR spectrum, the compound exists as its isomer phosphaneiminate [Cl5Mo(NPCl2NPCl3)] in CD2Cl2/CH3CN solution. The crystal structure of [Cl3PNPCl3][MoNCl4] is isotypic with that of [Cl3PNPCl3][MoOCl4] and shows the same kind of two-dimensional disorder. X-ray diffraction patterns show planes of diffuse scattering as well as Bragg reflexions. The latter correspond to an averaged structure with a = 1590.0, b = 1141.6, c = 418.0 pm, space group Pba2, Z = 2. In the averaged structure (606 reflexions, R = 0.071) the atom sites have fractional occupation. The real structure consists of square-pyramidal [MoNCl4]? ions stacked to form columns with alternating MoN distances of 175 and 243 pm. The packing of the columns is disordered in that the [MoNCl4]? pyramids point either in the +c or ?c direction. The [Cl3PNPCl3]+ ions are stacked in the c direction and show two types of disorder, namely a displacement parallel to c and a rotation by 120° about the P? P axis.  相似文献   
2.
Some relative rate experiments have been carried out at room temperature and at atmospheric pressure. This concerns the OH-oxidation of some oxygenated volatile organic compounds including methanol (k1), ethanol (k2), MTBE (k3), ethyl acetate (k4), n-propyl acetate (k5), isopropyl acetate (k6), n-butyl acetate (k7), isobutyl acetate (k8), and t-butyl acetate (k9). The experiments were performed in a Teflon-film bag smog chamber. The rate constants obtained are (in cm3 molecule−1 s−1): k1=(0.90±0.08)×10−12; k2=(3.88±0.11)×10−12; k3=(2.98±0.06)×10−12; k4=(1.73±0.20)×10−12; k5=(3.56±0.15)×10−12; k6=(3.97±0.18)×10−12; k7=(5.78±0.15)×10−12; k8=(6.77±0.30)×10−12; and k9=(0.56±0.11)×10−12. The agreement between the obtained rate constants and some previously published data has allowed for most of the studied compounds to point out a coherent group of values and to suggest recommended values. Atmospheric implications are also discussed. © 1998 John Wiley & Sons, Inc. Int J Chem Kinet 30: 839–847, 1998  相似文献   
3.

Background  

After sub-total hemi-section of cervical cord at level C7/C8 in monkeys, the ipsilesional hand exhibited a paralysis for a couple of weeks, followed by incomplete recovery of manual dexterity, reaching a plateau after 40–50 days. Recently, we demonstrated that the level of the plateau was related to the size of the lesion and that progressive plastic changes of the motor map in the contralesional motor cortex, particularly the hand representation, took place following a comparable time course. The goal of the present study was to assess, in three macaque monkeys, whether the hand representation in the ipsilesional primary motor cortex (M1) was also affected by the cervical hemi-section.  相似文献   
4.
ABSTRACT

ZnO transparent conductive films were deposited on glass substrates by sol-gel spin coating method. Taguchi method was used to find the optimal deposition parameters, three influential parameters were selected in this experiment, Concentration of zinc (II) ions. Zn2+, annealing temperature Tr and pre-annealing temperature TP. By employing the analysis of variance, we found that the annealing temperature Tr and the precursor Zn2+ are the most influencing parameters on the properties of ZnO films. Under the optimized deposition conditions, the ZnO films showed high crystal quality, and high transmittance of 90% in the visible region.  相似文献   
5.
Optical and Quantum Electronics - In this paper, a variable-coefficient generalized nonlinear Schrödinger equation, which can be used to describe the nonlinear phenomena in the optical fiber,...  相似文献   
6.
Dorai  Abderraouf 《Positivity》2021,25(5):2017-2027
Positivity - We prove a Korovkin-type theorem for sequences of positive linear operators on C([0, 1]). This theorem allows us to discuss some general results concerning positive linear...  相似文献   
7.
Undoped and aluminum-doped ZnO thin films are prepared by the sol–gel spin-coating process. Zinc acetate dihydrate, ethanol and mono-ethanolamine are used as precursor, solvent and stabilizer, respectively. The atomic percentage of dopant in solution were [Al/Zn] = 1 %, 2 % and 3 %. The effect of Al doping on the optical and electrical properties of ZnO films was investigated by X-ray diffraction (XRD), Four-Point probe technique and UV–visible spectrophotometery. The results from the X-ray diffraction show that the pure ZnO thin films had a polycrystalline structure of the hexagonal Wurtzite Type. A minimum resistivity of $3.3 \times 10^{-3} \Omega \cdot \mathrm{cm}$ was obtained for the film doped with 2 mol % Al. Optical transmissions reveal a good transmittance within the visible wavelength spectrum region for all of the films. The value of the band gap is enhanced from 3.21 eV (undoped ZnO) to 3.273 eV (Al/Zn = 3 %), the increase in the band gap can be explained by the Burstein–Moss effect.  相似文献   
8.
Spectroscopic and Crystallographic Characterization of [Cl3PNPCl3][MoOCl4] and Crystal Structure of [Cl3PNPCl3][MoCl6] [Cl3PNPCl3][MoCl6] was obtained by reaction of MoCl5 with [Cl3PNPCl3]Cl or [Cl3PNPCl3][PCl6]. Its crystal was determined by X-ray diffraction (R = 0.072 for 889 observed reflexions). Lattice parameters: a = 811.9, b = 2086, c = 1016 pm, β = 101.7°, space group P21/c, Z = 4. The [Cl3PNPCl3]+ ions have a similar structure as in Cl3PNPCl3 [PCl6] with PNP angles of 139°, but the crystal structures of the two compounds are not isotypic. Partial hydrolysis of [Cl3PNPCl3][MoCl6] yields [Cl3PNPCl3][MoOCl4] which forms green, very moisture sensitive crystals. X-ray diffraction patterns of [Cl3PNPCl3][MoOCl4] single crystals exhibit planes of diffuse scattered radiation perpendicular to c*, which show the presence of a two-dimensional disorder. Additional sharp reflexions correspond to an averaged structure with the lattice parameters a = 1598.4, b = 1141.2 and c = 415.1 pm, Z = 2, space group Pba2. Refinement of the averaged  相似文献   
9.
Journal of Sol-Gel Science and Technology - Quaternary semiconductor Cu2ZnSnS4 absorber material was synthesized by the sol-gel method deposited by the dip-coating technique on ordinary glass...  相似文献   
10.
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