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81.
82.
83.
A calix[5]arene based solvent extraction reagent 3, appending carboxylic acid groups at the lower rim, has been developed and its complexation behavior towards some transition metal ions has been studied. The host 3 can selectively and quantitatively extract Pb(II) ions above pH 1.8 while other divalent ions such as Cu(II), Zn(II), Co(II), Ni(II) are extracted quantitatively only above pH 3.0. The outstanding Pb(II) selectivity of 3 comes from the size fit complementarity effect of the Pb(II) ion in the calix[5]arene cavity. One molecule of 3 extracts two Pb(II) ions in a stepwise manner. The first Pb(II) ion is extracted into the deep cavity of the calix[5]arene defined by phenoxy oxygen atoms. The first complexed Pb(II) ion acts as a template to bring the host into a cone conformation and induces a positive allosteric effect for the extraction of the second Pb(II) ion at an oxygen rich coordinating site composed of carboxyl groups. Both the Pb(II) ions are extracted through an ion exchange mechanism and the electroneutral complex in the organic phase is formed by the release of an equivalent number of hydrogen ions into aqueous solution. The loaded Pb(II) is easily back-extracted from Pb(II)-complexed 3 using dilute acid solution. 相似文献
84.
85.
[NiFe]Hydrogenase from Citrobacter sp. S‐77 Surpasses Platinum as an Electrode for H2 Oxidation Reaction 下载免费PDF全文
Dr. Takahiro Matsumoto Shigenobu Eguchi Dr. Hidetaka Nakai Prof. Takashi Hibino Dr. Ki‐Seok Yoon Prof. Seiji Ogo 《Angewandte Chemie (International ed. in English)》2014,53(34):8895-8898
Reported herein is an electrode for dihydrogen (H2) oxidation, and it is based on [NiFe]Hydrogenase from Citrobacter sp. S‐77 ([NiFe]S77). It has a 637 times higher mass activity than Pt (calculated based on 1 mg of [NiFe]S77 or Pt) at 50 mV in a hydrogen half‐cell. The [NiFe]S77 electrode is also stable in air and, unlike Pt, can be recovered 100 % after poisoning by carbon monoxide. Following characterization of the [NiFe]S77 electrode, a fuel cell comprising a [NiFe]S77 anode and Pt cathode was constructed and shown to have a a higher power density than that achievable by Pt. 相似文献
86.
Akiko Hori Kyosuke Nakajima Hidetaka Yuge 《Acta Crystallographica. Section C, Structural Chemistry》2014,70(10):960-964
The Cu2+ ions in the title compounds, namely bis[1,3‐bis(pentafluorophenyl)propane‐1,3‐dionato‐κ2O,O′]copper(II) p‐xylene n‐solvate, [Cu(C15HF10O2)2]·nC8H10, with n = 1, (I), n = 2, (II), and n = 4, (III), are coordinated by two 1,3‐bis(pentafluorophenyl)propane‐1,3‐dionate ligands. The coordination complexes of (I) and (II) have crystallographic inversion symmetry at the Cu atom and the p‐xylene molecule in (I) also lies across an inversion centre. The p‐xylene molecules in (I) and (II) interact with the pentafluorophenyl groups of the complex via arene–perfluoroarene interactions. In the crystal of (III), two of the p‐xylene molecules interact with the pentafluorophenyl groups via arene–perfluoroarene interactions. The other two p‐xylene molecules are located on the CuO4 coordination plane, forming a uniform cavity produced by metal...π interactions. 相似文献
87.
A q-difference analog of the sixth Painlevé equation is presented. It arises as the condition for preserving the connection matrix of linear q-difference equations, in close analogy with the monodromy-preserving deformation of linear differential equations. The continuous limit and special solutions in terms of q-hypergeometric functions are also discussed. 相似文献
88.
Image processing procedures for noise reduction and image registration in the Pressure Sensitive Paint (PSP) experiments are
investigated. A several types of filter are examined for the removal of shot noise. An algorithm to detect a marker cell located
on the model surface is proposed and an appropriate marker size is discussed. The digital processing based on the wavelet
transform is effective to reduce the shot noise and to enhance the edge of the model. The algorithm to sharpen the edge of
the model using wavelet transforms is developed. The results indicate that the methods developed in this study effectively
remove the shot noise and correct the displacement of the model on the images taken during the wind-on. 相似文献
89.
Ian Graham Hidetaka Hamada Gabriela Kohr Mirela Kohr 《Journal d'Analyse Mathématique》2008,105(1):267-302
In this paper, we define the notion of asymptotic spirallikeness (a generalization of asymptotic starlikeness) in the Euclidean
space ℂ
n
. We consider the connection between this notion and univalent subordination chains. We introduce the notions of A-asymptotic spirallikeness and A-parametric representation, where A ∈ L(ℂ
n
, ℂ
n
), and prove that if
dt < ∞ (this integral is convergent if k
+(A) < 2m(A)), then a mapping f ∈ S(B
n
) is A-asymptotically spirallike if and only if f has A-parametric representation, i.e., if and only if there exists a univalent subordination chain f(z, t) such that D f(0, t) = e
At
, {e
−At
f(·, t)}
t≥0 is a normal family on B
n
and f = f(·, 0). In particular, a spirallike mapping with respect to A ∈ L(ℂ
n
, ℂ
n
) with
dt < ∞ has A-parametric representation. We also prove that if f is a spirallike mapping with respect to an operator A such that A + A* = 2I
n
, then f has parametric representation (i.e., with respect to the identity). Finally, we obtain some examples of asymptotically spirallike
mappings.
Partially supported by the Natural Sciences and Engineering Research Council of Canada under Grant A9221.
Partially supported by Grant-in-Aid for Scientific Research (C) no. 19540205 from Japan Society for the Promotion of Science,
2007.
Partially supported by Romanian Ministry of Education and Research, CEEX Program, Project 2-CEx06-11-10/2006. 相似文献
90.
Lise Joost Støckler Rasmus Stubkjær Christensen Magnus Kløve Andreas Dueholm Bertelsen Anders Bæk Borup Prof. Dr. Lennard Krause Seiya Takahashi Dr. Tomoki Fujita Prof. Dr. Hidetaka Kasai Dr. Ichiro Inoue Prof. Dr. Eiji Nishibori Prof. Dr. Dr. Dr. Bo Brummerstedt Iversen 《Chemphyschem》2023,24(23):e202300407
X-ray scattering data measured on femtosecond timescales at the SACLA X-ray Free Electron Laser (XFEL) facility on a suspension of HfO2 nanoparticles in a liquid jet were used for pair distribution function (PDF) analysis. Despite a non-optimal experimental setup resulting in a modest Qmax of ~8 Å−1, a promising PDF was obtained. The main features were reproduced when comparing the XFEL PDF to a PDF obtained from data measured at the PETRA III synchrotron light source. Refining structural parameters such as unit cell dimension and particle size from the XFEL PDF provided reliable values. Although the reachable Qmax limited the obtainable information, the present results indicate that good quality PDFs can be obtained on femtosecond timescales if the experimental conditions are further optimized. The study therefore encourages a new direction in ultrafast structural science where structural features of amorphous and disordered systems can be studied. 相似文献