Coalition-hierarchical game under uncertainty conditions

An optimization problem in a coalition-hierarchical game under uncertainty conditions is formulated. In the game, information assumptions are that the player of the high hierarchical level (controlling Center) and each low-level coalition estimates uncertainty in its own way. The Center constructs its strategy from the maximum condition for its own payoff function and its minimum in uncertainty. The relationships between coalitions are built upon the guaranteeing absolute active equilibrium understood in the sense of providing the players with guaranteed payoff under the actual uncertainty. The guaranteed uncertainty is obtained with the help of Slater principle. The total equilibrium in the game is called CH-equilibrium. For a quadratic game version, sufficient optimality conditions are obtained. A numerical procedure for solving the game is described and an example is given.     

Harvesting Lost Photons: Plasmon and Upconversion Enhanced Broadband Photocatalytic Activity in Core@Shell Microspheres Based on Lanthanide‐Doped NaYF4, TiO2, and Au

Efficiently harvesting solar energy for photocatalysis remains very challenging. Rational design of architectures by combining nanocomponents of radically different properties, for example, plasmonic, upconversion, and photocatalytic properties, offers a promising route to improve solar energy utilization. Herein, the synthesis of novel, plasmonic Au nanoparticle decorated NaYF₄:Yb³⁺, Er³⁺, Tm³⁺‐core@porous‐TiO₂‐shell microspheres is reported. They exhibit high surface area, good stability, broadband absorption from ultraviolet to near infrared, and excellent photocatalytic activity, significantly better than the benchmark P25 TiO₂. The enhanced activity is attributed to synergistic effects from nanocomponents arranged into the nanostructured architecture in such a way that favors the efficient charge/energy transfer among nanocomponents and largely reduced charge recombination. Optical and energy‐transfer properties are modeled theoretically to support our interpretations of catalytic mechanisms. In addition to yielding novel materials and interesting properties, the current work provides physical insights that can contribute to the future development of plasmon‐enhanced broadband catalysts.     

Bioconjugated superstructures of CdTe nanowires and nanoparticles: multistep cascade Förster resonance energy transfer and energy channeling

Nanoparticle/nanowire assemblies with a degree of radial organization were prepared around luminescent semiconducting CdTe nanowires using bioconjugation with streptavidin and D-biotin linkers. Red-emitting nanowires (6.62 +/- 1.55 nm diameter, 512 +/- 119 nm length) and green-emitting nanoparticles (3.2 +/- 0.7 nm diameter) were surface-modified with biotin, while orange-emitting nanoparticles (4.1 +/- 1.2 nm diameter) were decorated with streptavidin. CdTe nanocrystals produced two fuzzy layers around the nanowires in which the diameter of CdTe nanoparticles decreased with the distance from the nanowire axis. F?rster resonance energy transfer (FRET) from the outside layer of nanoparticles to the central nanowire was observed for nanowires conjugated with 4.1 nm CdTe. Addition of 3.2 nm CdTe resulted in a red-orange-green optical progression with band gaps of CdTe decreasing toward the axis of the superstructure. In this case, 4-fold luminescence enhancement of the nanowire luminescence was observed and was attributed to multistep FRET. This observation indicated the accumulation of photogenerated excitons in the cascade terminal. A simple model of multiconjugated superstructure with cascade energy transfer is developed and used to describe and understand the experimental data. The experimental data and theoretical model suggest the possibility of utilization of the prepared superstructures with radial symmetry in several classes of optoelectronic devices including nanomaterials for energy collection. They can also be a convenient model object for the investigation of methods of energy funneling in nanoscale assemblies.     

Analysis of the operational reliability of a power-generating unit with a BN-600 reactor during the period 1980–1993

Conclusions The high quality of the design and the additional improvements to separate units of the main equipment and systems at the initial stage of operation (first main circulation pump, steam generators, safety and control system) ensured reliable operation of the power-generating unit. The reliability indicators are as follows (%): the installed-power utilization factor, the technical utilization factor, and the availability factor were 68.7, 75.7, and 97.2, respectively. The maximum power utilization factor of 77% was achieved in 1988. The safety limits set by the reactor design were not exceeded during the disruption of normal operation of the power-generating unit as a result of equipment failures and personnel errors. The largest number of disruptions (∼75%) occurred during 1980–1986, the average number of disruptions per year was ∼7, and four cases per year occurred in 1987 to 1990. During the most recent period (1988–1993) disruptions of normal operation of the unit (21 cases) were connected mainly with failures of the turbogenerators (five cases) and equipment failures in the third loop (three cases). Beloyarsk Nuclear Power Plant. Translated from Atomnaya énergiya, Vol. 76, No. 3, pp. 167–171, March, 1994.     

Carburizing in a conducting fluidized bed

Metal Science and Heat Treatment -     

Intensifying Heat Using MOF-Isolated Graphene for Solar-Driven Seawater Desalination at 98% Solar-to-Thermal Efficiency

Photothermal materials are crucial for diverse heating applications, but it remains challenging to achieve high energy conversion efficiency due to the difficulty to concurrently improve light absorbance and suppress heat loss. Herein, a zeolitic imidazolate framework-isolated graphene (G@ZIF) nanohybrid is demonstrated that utilizes ultrathin, heat-insulating ZIF layers, and G@ZIF interfacial nanocavity to synergistically intensify light absorbance and heat localization. Under artificial sunlight illumination (≈1 kW m⁻²), the G@ZIF film attains a maximum temperature of 120 °C in an open environment with a 98% solar-to-thermal conversion efficiency. Importantly, the porous ZIF layer allows small molecules/media to enter and access the embedded hot graphene surface for targeted heat transfer in practical applications. As a proof-of-concept, the G@ZIF-based steam generator realizes 96% energy conversion from light to vapor with near-perfect desalination and water purification efficiencies (>99.9%). This design is generic and can be extended to other photothermal systems for advanced solar-thermal applications, including catalysis, water treatments, sterilization, and mechanical actuation.     

Effects of Coulomb interaction in the magneto-capacitance of quantum wires

The magneto-capacitance of quantum wires with interacting electrons is studied theoretically. The gate-voltage-dependence of the capacitance of wires in the Wigner crystal regime exhibits specific features related to structural phase transitions. In the quantum Hall regime, we consider the formation of the incompressible liquid strip in the center of a parabolic wire, that leads to an asymmetrical minimum in the voltage-dependence of capacitance.