Nature can efficiently recognize specific ions by exerting second-sphere interactions onto well-folded protein scaffolds. However, a considerable challenge remains to artificially manipulate such affinity, while being cost-effective in managing immense amounts of water samples. Here, we propose an effective approach to regulate uranyl capture performance by creating bio-inspired nano-traps, illustrated by constructing chelating moieties into porous frameworks, where the binding motif’s coordinative interaction towards uranyl is enhanced by introducing an assistant group, reminiscent of biological systems. Representatively, the porous framework bearing 2-aminobenzamidoxime is exceptional in sequestering high uranium concentrations with sufficient capacities (530 mg g−1) and trace quantities, including uranium in real seawater (4.36 mg g−1, triple the benchmark). Using a combination of spectroscopic, crystallographic, and theory calculation studies, it is revealed that the amino substituent assists in lowering the charge on uranyl in the complex and serves as a hydrogen bond acceptor, boosting the overall uranyl affinity of amidoxime.
Preorganization is a basic design principle used by nature that allows for synergistic pathways to be expressed. Herein, a full account of the conceptual and experimental development from randomly distributed functionalities to a convergent arrangement that facilitates cooperative binding is given, thus conferring exceptional affinity toward the analyte of interest. The resulting material with chelating groups populated adjacently in a spatially locked manner displays up to two orders of magnitude improvement compared to a random and isolated manner using uranium sequestration as a model application. This adsorbent shows exceptional extraction efficiencies, capable of reducing the uranium concentration from 5 ppm to less than 1 ppb within 10 min, even though the system is permeated with high concentrations of competing ions. The efficiency is further supported by its ability to extract uranium from seawater with an uptake capability of 5.01 mg g−1, placing it among the highest‐capacity seawater uranium extraction materials described to date. The concept presented here uncovers a new paradigm in the design of efficient sorbent materials by manipulating the spatial distribution to amplify the cooperation of functions.
The standard perturbative weak-coupling expansions in lattice models are
asymptotic. The reason for this is hidden in the incorrect interchange of the
summation and integration. However, substituting the Gaussian initial
approximation of the perturbative expansions by a certain interacting model or
regularizing original lattice integrals, one can construct desired convergent
series. In this paper we develop methods, which are based on the joint and
separate utilization of the regularization and new initial approximation. We
prove, that the convergent series exist and can be expressed as the re-summed
standard perturbation theory for any model on the finite lattice with the
polynomial interaction of even degree. We discuss properties of such series and
make them applicable to practical computations. The workability of the methods
is demonstrated on the example of the lattice $\phi^4$-model. We calculate the
operator $\langle\phi_n^2\rangle$ using the convergent series, the comparison
of the results with the Borel re-summation and Monte Carlo simulations shows a
good agreement between all these methods.Comment: 25 pages, 14 figure
Many particle quantum hydrodynamics based on the Darwin Hamiltonian (the Hamiltonian corresponding to the Darwin Lagrangian) is considered. A force field appearing in corresponding Euler equation is considered in details. Contributions from different terms of the Darwin Hamiltonian in the Euler equation are traced. For example, the relativistic correction to the kinetic energy of particles leads to several terms in the Euler equation, these terms have different form. One of them has a form similar to a term appearing from the Darwin term. Hence, the two different mechanisms give analogous contributions in wave dispersion. Microscopic analog of the Biot-Savart law, called the current-current interaction and describing an interaction of moving charges via the magnetic field, is also included in our description. The semi-relativistic generalization of the quantum Bohm potential is obtained. Contribution of the relativistic effects in the spectrum of plasma collective excitations is considered.
Microscopic derivation of the Coulomb exchange interaction for electrons
located on the nanotubes is presented. Our derivation is based on the
many-particle quantum hydrodynamic method. We demonstrate the role of the
curvature of the nanocylinders on the force of the exchange interaction. We
calculate corresponding dispersion dependencies for electron oscillations on
the nanotubes.Comment: 10 pages, 9 figure
Институт физической химии и электрохимии имени А. Н. Фрумкина РАН, Москва 3 Институт проблем безопасного развития атомной энергетики РАН, Москва 4 АО «Опытно-демонстрационный центр вывода из эксплуатации уран-графитовых ядерных реакторов», г. Северск Статья поступила в редакцию 7 мая 2019 г Рассмотрено состо ние работ и исследовани по обра ени с облу енным реакторным ра итом редло ены варианты оптими а ии расходов на ахоронение Р вкл а ра работку и применение методов де актива ии сни ени активности ра итовых Р сни ени стоимости про едур конди ионировани Р а так е со дание спе иали ированно о пункта ахоронени Р писаны основные пути дл достиени про ресса и уто нени плана исследовани и ра работок в асти удалени ра ита на ахоронение Ключевые слова: радиоактивные отходы радиоу лерод реакторны ра ит уран ра итовы реактор ахоронение Р пункт ахоронени Р
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