Tailoring the Asymmetric Structure of NH2-UiO-66 Metal-Organic Frameworks for Light-promoted Selective and Efficient Gold Extraction and Separation

Designing adsorption materials with high adsorption capacities and selectivities is highly desirable for precious metal recovery. Desorption performance is also particularly crucial for subsequent precious metal recovery and adsorbent regeneration. Herein, a metal–organic framework (MOF) material (NH₂-UiO-66) with an asymmetric electronic structure of the central zirconium oxygen cluster has an exceptional gold extraction capacity of 2.04 g g⁻¹ under light irradiation. The selectivity of NH₂-UiO-66 for gold ions is up to 98.8 % in the presence of interfering ions. Interestingly, the gold ions adsorbed on the surface of NH₂-UiO-66 spontaneously reduce in situ, undergo nucleation and growth and finally achieve the phase separation of high-purity gold particles from NH₂-UiO-66. The desorption and separation efficiency of gold particles from the adsorbent surface reaches 89 %. Theoretical calculations indicate that -NH₂ functions as a dual donor of electrons and protons, and the asymmetric structure of NH₂-UiO-66 leads to energetically advantageous multinuclear gold capture and desorption. This adsorption material can greatly facilitate the recovery of gold from wastewater and can easily realize the recycling of the adsorbent.     

去除内毒素的柱亲和介质与膜亲和介质的制备和特征

以琼脂糖和尼龙６６微孔滤膜为原料，发展了两种用于去 内毒素的不同类型的亲和介质。在对原料进行化学改性后，键合了含六个碳原子的间隔臂和组氨酸亲和配基。它们对内毒素的亲和容量分别为２．０ｍｇ／ｇ和０．２ｍｇ／ｇ，内毒素和介质之间的表观解离常数分别为８．１＊１０＾－１０ｍｏｌ／Ｌ和３．０＊１０＾－８ｍｏｌ／Ｌ。     

Metal-organic framework as a multi-component sensor for detection of Fe3+, ascorbic acid and acid phosphatase

In this research,a hydroxyl group functionalized metal-organic framework(MOF),UiO-66-(OH)₂,was synthesized as a "on-off-on" fluore scent switching nanoprobe for highly sensitive and selective detection of Fe³⁺,ascorbic acid(AA) and acid phosphatase(ACP).UiO-66-(OH)₂ emits yellow-green light under ultraviolet light,when Fe³⁺ was added,Fe³⁺ was chelated with hydroxyl group,the electrons in the excited state S_1 of the MOF transferred to the half-filled 3 d orbits of Fe³⁺,resulting in fluorescence quenching because of the nonradiative electron/hole recombination annihilation.AA could reduce Fe³⁺ to Fe²⁺,which can destroy the electron transfer between UiO-66-(OH)₂ and Fe³⁺ after AA adding,resulted in nonoccurrence of the nonradiative electron transfer,leading to the recovery of UiO-66-(OH)₂ fluorescence intensity.The probe can also be used to detect ACP based on the enzymolysis of 2-phospho-L-ascorbic acid(AAP) to produce AA.Benefitting from the hydroxyl group and the characteristics of UiO-66,including the high porosity and large surface area,the developed UiO-66-(OH)₂ showed extensive advantages as a fluorescent probe for detection of multi-component,such as high sensitivity and selectivity,colorimetric detection,fast response kinetics and easy to operate,economical and secure.This is the first time to use active group functionalized MOFs as a multicomponent sensor for these three substances detection.     

Representations of the Lie algebra of vector fields on a sphere

For an affine algebraic variety X we study a category of modules that admit compatible actions of both the algebra A of functions on X and the Lie algebra of vector fields on X. In particular, for the case when X is the sphere ${\mathbb{S}}^2$, we construct a set of simple modules that are finitely generated over A. In addition, we prove that the monoidal category that these modules generate is equivalent to the category of finite-dimensional rational ${\mathrm{GL}}_2$-modules.     

Thermoluminescence and absorption spectra of CdSe quantum dot-doped glass irradiated by X-rays

Thermally stimulated luminescence (TSL) of aluminoborosilicate glass doped with CdSe nanoparticles (28 and 47 Å) has been studied after exposure to ionizing radiation; the intense TSL peaks were observed at temperatures 150 and 85 °C, respectively. The optical absorption spectra, as well as TSL of the irradiated samples containing CuBr nanoparticles (44 Å) were also measured. In the case of CuBr, TSL was observed neither before nor after irradiation. The dependence of TSL intensity on irradiation time indicates that glass activated by CdSe nanoparticles shows promise as a dosimetric material.     

Invariant Operators Between Spaces of h-Monogenic Polynomials

In this paper we study properties of invariant differential operators acting between spaces of h-monogenic functions. In this way one obtains differential operators acting between invariant (m)-modules which can be seen as the Hermitean analogues of the classical Rarita-Schwinger operators. Received: October, 2007. Accepted: February, 2008.     

A general form of Jordan-type double inequality for the generalized and normalized Bessel functions

In this note, a general form of Jordan-type double inequality involving the generalized and normalized Bessel functions is presented, and then some recent results concerning generalized and sharp work of Jordan’s inequality are extended. At the same time, the applications of the results above give two new infinite series for sinx/x and sinhx/x.     

Faber polynomials, Cayley-Hamilton equation and Newton symmetric functions

We give an explicit formula for the Faber polynomials and for generalized Faber polynomials introduced by H. Airault and J. Ren in [H. Airault, J. Ren, An algebra of differential operators and generating functions on the set of univalent functions, Bull. Sci. Math. 126 (5) (2002) 343-367]. We introduce a new family of polynomials related to the Faber polynomials of the second kind. This allows us to give a generalized Cayley-Hamilton equation.     

Factorization of staircase class operators in Hilbert space

A class of linear bounded staircase operators (H, G spaces) defined by (1) with two infinite sequences of orthogonal decompositions ofH and chain property (2) is considered. Necessary and sufficient conditions for the factorizationZ=XY are obtained, whereX, Y are block-diagonal, bounded, andY has a bounded inverse. All the pairs (X, Y) are explicitly constructed. These conditions are specialized for finite and infinite dimensions of the blocks ofX, Y and for differentX, Y. A direct application to bitriangular and biquasitriangular operators is indicated.     

Quantum Clifford Hopf gebra for quantum field theory

We give arguments for the necessity to employ quantum Clifford Hopf gebras in quantum field theory. The role of the antipode is examined, Feynman diagrams are re-interpreted as tangles of graphical calculus. Regularization due to the design of convolution Hopf gebras is given as a program for future research.