Mesoporous Li 3 V 2 (PO 4 ) 3 -carbon (LVP-C) microspheres are synthesized using Baker's yeast cells as both mesoporous structure templates and amorphous carbon sources. We find that the vanadium cations are combined with the negatively charged hydrophilic groups and are self-assembled both on the yeast cell wall surface and inside the cell by electrostatic interaction and metabolism regulation, respectively. The self-assembly leads to the formation of LVP-C microspheres with diameters of 1-8 mm. These microspheres are composed of densely aggregated nanoparticles (20-40 nm) as well as interconnected nanopores (2-15 nm), and hence they are of mesoporous nature. The nanoparticles can be easily brought into contact with electrolyte, and the open mesoporous structure allows lithium ions to easily penetrate into the microspheres. The carbon network (16.4 wt.%) on the surface of the Li 3 V 2 (PO 4 ) 3 nanoparticles facilitates electron diffusion. The mesoporous LVP-C microspheres have a high discharge capacity (about 126.7 mAh g À1 ), only 2% capacity loss of the initial value at the 50th cycle at a current density of 0.2 C, and a high rate capacity of 100.5 mAh g À1 at 5 C in the region of 3.0-4.3 V. The apparent Li + diffusion coefficient is found to be 6.76 Â 10 À10 cm 2 s À1 . The microspheres could be an ideal cathode-active material that fulfills the requirements of rechargeable lithium batteries for high power applications.

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LiFePO 4 has emerged as the cathode material of choice for high-power lithium-ion batteries as it offers much higher energy density and excellent structural stability than other cathode materials. However, its performance factors such as energy density, power density, and cycle life depend on the nanoparticle morphology of LiFePO 4 . This paper provides an overview of the effects of nanoparticle morphology on the electrochemical performances of LiFePO 4 . The crystal structure and structural model of LiFePO 4 are depicted in detail. The synthetic methods, formation principles, characteristics and morphologyperformance relationships of LiFePO 4 nanoparticles, including LiFePO 4 /C nanocomposite particles, LiFePO 4 nanorods and LiFePO 4 nanowires are investigated. This is a typical review but it does not cover all nanostructured LiFePO 4 cathodes reported in the literature. Our major goal is to highlight some new progress in using the LiFePO 4 nanoparticles as cathodes to develop lithium batteries with high energy density, high rate capability, and excellent cycling stability.

Bioactive glasses with hierarchical nanoporosity and structures have been heavily involved in immobilization of enzymes. Because of meticulous design and ingenious hierarchical nanostructuration of porosities from yeast cell biotemplates, hierarchically nanostructured porous bioactive glasses can provide a simple, cost-effective way to enhance catalytic activity of directly immobilized enzyme. Its unique chemical surface properties and hierarchical meso/macroporous structures lead to highly effi cient catalytic performances of the directly immobilized enzymes. The enzyme molecules were spontaneously entrapped into the highly curved macropores (200-500 nm) via multipoint metal ion binding in electrical double layers. Hence, the enzyme activity and enzyme loading were enhanced, the cost of enzyme use was reduced, showing higher thermal and storage stabilities than free enzyme. The reactant and products of catalytic reactions can freely diffuse through open mesopores (2-40 nm). The formation mechanism of hierarchically structured porous bioactive glasses, the immobilization mechanism of enzyme and the catalysis mechanism of immobilized enzyme are then discussed. The novel nanostructure with advanced properties is expected to be utilized as a solid support for any enzyme for bioconversion, bioremediation, biosensors and drugs.

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Free vibration analysis of simply supported beams with solid and thin-walled cross-sections using higher-order theories based on displacement variables / Dan, M.; Pagani, A.; Carrera, E.. -In: THIN-WALLED STRUCTURES. -ISSN 0263-8231. -STAMPA. -98:Part B(2016), pp. 478-495. OriginalFree vibration analysis of simply supported beams with solid and thin-walled cross-sections using higher-order theories based on displacement variables Publisher:Published ABSTRACT Solutions for undamped free vibration of beams with solid and thin-walled cross-sections are provided by using refined theories based on displacement variables. In essence, higher-order displacement fields are developed by using the Carrera Unified Formulation (CUF), and by discretizing the cross-section kinematics with bilinear, cubic and fourth-order Lagrange polynomials. Subsequently, the differential equations of motion and the natural boundary conditions are formulated in terms of fundamental nuclei by using CUF and the strong form of the principle of virtual displacements. The second-order system of ordinary differential equations is then reduced into a classical eigenvalue problem by assuming simply-supported boundary conditions. The proposed methodology is extensively assessed for different solid and thin-walled metallic beam structures and the results are compared with those appeared in published literature and also checked by finite element solutions. The research demonstrates that: i) The innovative 1D closed form CUF represents a reliable and compact method to develop refined beam models with solely displacement variables; ii) 3D-like numerically exact solutions of complex structures can be obtained with ease; iii) The numerical efficiency of the present method is uniquely robust when compared to other methods that provide similar accuracies.