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1.
Synthesis,Characterization, and Photoluminescence Properties of Silver(I) Metal‐Organic Polymers with Nanochannels Based on 2‐Sulfoterephthalic Acid and Di(pyridin‐2‐yl)amine Ligands 下载免费PDF全文
Hui Huang Mahmood Payehghadr Jie Wang Hong‐Ping Xiao Ai‐Yin Wang Xin‐Hua Li Ali Morsali 《Helvetica chimica acta》2014,97(3):345-354
Two new silver(I) 3D coordination polymers, namely [Ag3(2‐stp)(dpa)]n ( 1 ) and {[Ag2(2‐stp)(H2O)]?Hdpa}n ( 2 ) (2‐NaH2stp=sodium 2,5‐dicarboxysulfonate, dpa=di(pyridine‐2‐yl)amine) were synthesized. The complexes were characterized by elemental analysis, FT‐IR spectra, thermogravimetric analyses (TGA), and single‐crystal X‐ray diffraction. In complex 1 , three neighboring Ag ions are bridged by N‐ and O‐atom, forming a 3D coordination network. The molecular structure of 2 is cation? anion species, forming 3D host? guest supramolecular network with the [Hdpa]+ cations encapsulated in the nanochannels. The photoluminescence properties of the complexes were also investigated in the solid state at room temperature. 相似文献
2.
The use of a polymer inclusion membrane in a paper-based sensor for the selective determination of Cu(II) 总被引:1,自引:0,他引:1
B. Manori Jayawardane Lilibeth dlC. Coo Robert W. Cattrall Spas D. Kolev 《Analytica chimica acta》2013
A disposable paper-based sensor (PBS) is described for the determination of Cu(II) in natural and waste waters at approximately 2 cents per measurement. The device makes use of a polymer inclusion membrane (PIM) to provide the selectivity for Cu(II). The PIM consists of 40 wt% di(2-ethlyhexyl) phosphoric acid (D2EHPA) as the carrier, 10 wt% dioctyl phthalate (DOP) as a plasticizer, 49.5 wt% poly(vinyl chloride) (PVC) as the base polymer and 0.5 wt% (m m−1) 1-(2′-pyridylazo)-2-naphthol (PAN) as the colourimetric reagent. High selectivity under mildly acidic conditions (HCl, pH 2.0) is achieved for Cu(II) in the presence of frequently encountered metal ions in natural and waste waters such as Fe(III), Al(III), Zn(II), Cd(II), Pb(II), Ca(II), Mg(II), and Ni(II). 相似文献
3.
We have shown that the non-Abelian spin-orbit gauge field strength of the Rashba and Dresselhaus interactions, when split into two Abelian field strengths, the Hamiltonian of the system can be re-expressed as a Landau level problem with a particular relation between the two coupling parameters. The quantum levels are created with up and down spins with opposite chirality and leads to the quantum spin Hall effect. 相似文献
4.
5.
A. Perali M. Sindel G. Kotliar 《The European Physical Journal B - Condensed Matter and Complex Systems》2001,24(4):487-503
A number of normal state transport properties of cuprate superconductors are analyzed in detail using the Boltzmann equation.
The momentum dependence of the electronic structure and the strong momentum anisotropy of the electronic scattering are included
in a phenomenological way via a multi-patch model. The Brillouin zone and the Fermi surface are divided in regions where scattering between the electrons
is strong and the Fermi velocity is low (hot patches) and in regions where the scattering is weak and the Fermi velocity is
large (cold patches). We present several motivations for this phenomenology starting from various microscopic approaches.
A solution of the Boltzmann equation in the case of N patches is obtained and an expression for the distribution function away from equilibrium is given. Within this framework,
and limiting our analysis to the two patches case, the temperature dependence of resistivity, thermoelectric power, Hall angle,
magnetoresistance and thermal Hall conductivity are studied in a systematic way analyzing the role of the patch geometry and
the temperature dependence of the scattering rates. In the case of Bi-based cuprates, using ARPES data for the electronic
structure, and assuming an inter-patch scattering between hot and cold states with a linear temperature dependence, a reasonable
agreement with the available experiments is obtained.
Received 3 August 2001 and Received in final form 1st November 2001 相似文献
6.
Rajendran Murugan Murugesan Karthikeyan Paramasivam T. Perumal Boreddy S.R. Reddy 《Tetrahedron》2005,61(52):12275-12281
Efficient electrophilic substitution reactions of indoles with various aldehydes proceed smoothly in acetonitrile using heteropoly acid (H4[Si(W3O10)3]) to afford the corresponding new indolyl crown ethers and di(indolyl)pyrazolyl methanes. H4[Si(W3O10)3] is also found to catalyze the Michael addition of indoles to ,β-unsaturated compounds for the synthesis of 3-alkylated indoles. 相似文献
7.
W. Rohrbeck E. Chilla H.-J. Fröhlich J. Riedel 《Applied Physics A: Materials Science & Processing》1991,52(5):344-347
A new method for the investigation of ultrasonic waves on surfaces of solids based on scanning tunneling microscopy is presented. A sinusoidal high frequency signal is added to the tip voltage. Hence the tunneling current contains a component whose frequency is the difference of the frequencies of the acoustic wave field and the ac tip voltage. Amplitude and phase of this component carry the full information about the wave field. 相似文献
8.
P. Dietz P. Hansma K. Fostiropoulos W. Krätschmer 《Applied Physics A: Materials Science & Processing》1993,56(3):207-210
C60/C70 crystal surfaces were imaged by atomic force microscopy under ethanol with resolution of single molecules. Spherical and elongated elliptical fullerenes can be distinguished corresponding most likely with C60, respectively C70. Determination of the maximum diameter for a large number of molecules confirms the presence of two species of fullerenes, one with 9.4 Å, the other with 11.2 Å. The measured ratio C60:C70 is 81:19 which resembles the spectroscopical data. The molecules are arranged either in hexagonal (hcp) or cubic (fcc) packing, in some areas the two arrangements alternate within a few nm. Elongated fullerenes apparently prefer the hexagonal packing. 相似文献
9.
D2EHPA萃取稀土的有机相红外光谱及添加DMHPA的影响 总被引:6,自引:1,他引:5
本文研究了部分皂化的二(2-乙基己基)磷酸(D2EHPA)-正庚烷体系萃取稀土离子Y^3+,Pr^3+,Nd^3+,Eu^3+后有机的傅里叶变换红外光谱(FT-IR)。发现不同稀土离子与萃取剂的配位能力有差异,并且皂化度对萃取有机相中的P=O谱带的频率和吸收强度皆有影响,在D2EHPA中加入二(1-甲基庚基)磷酸(DMHPA)导致P=O谱带形状和吸收强度发生变化。 相似文献
10.
J.-J. Shi B.C. Sanders S.-H. Pan 《The European Physical Journal B - Condensed Matter and Complex Systems》1998,4(1):113-119
We calculate the electron-phonon scattering rate for an asymmetric double barrier resonant tunneling structure based on dielectric
continuum theory, including all phonon modes, and show that interface phonons contribute much more to the scattering rate
than do bulk-like LO phonons for incident energies which are approximately within an order of magnitude of the Fermi energy.
The maximum scattering rate occurs for incident electron energies near the quantum well resonance. Subband nonparabolicity
has a significant influence on electron-phonon scattering in these structures. We show that the relaxation time is comparable
to the dwell time of electrons in the quantum well for a typical resonant tunneling structure.
Received: 23 December 1997 / Revised: 24 March 1998 / Accepted: 9 March 1998 相似文献