University of Science and Technology Beijing

About: University of Science and Technology Beijing is a education organization based out in Beijing, China. It is known for research contribution in the topics: Microstructure & Alloy. The organization has 41558 authors who have published 44473 publications receiving 623229 citations. The organization is also known as: Beijing Steel and Iron Institute.

Boundary Adaptive Robust Control of a Flexible Riser System With Input Nonlinearities

Abstract: This paper focuses on adaptive robust vibration control for flexible riser systems affected by input nonlinearities and unknown external disturbances. An auxiliary system is constructed and adjusted to develop a boundary adaptive robust control for restraining the vibrational offset and eliminating the effect of input nonlinearities. Besides, an adaptive law of boundary disturbance upper-bound is constructed together with the vibration control strategy to estimate the magnitude of unknown boundary disturbance. Further, the convergence of states and stability of the system are ensured with the developed control scheme. By choosing the proper control parameters, the control performance is verified with the obtained simulation results.

Environmentally Friendly Solvent-Processed Organic Solar Cells that are Highly Efficient and Adaptable for the Blade-Coating Method.

Abstract: The power conversion efficiencies (PCEs) of state-of-the-art organic solar cells (OSCs) have increased to over 13%. However, the most commonly used solvents for making the solutions of photoactive materials and the coating methods used in laboratories are not adaptable for future practical production. Therefore, taking a solution-coating method with environmentally friendly processing solvents into consideration is critical for the practical utilization of OSC technology. In this study, a highly efficient PBTA-TF:IT-M-based device processed with environmentally friendly solvents, tetrahydrofuran/isopropyl alcohol (THF/IPA) and o-xylene/1-phenylnaphthalene, is fabricated; a high PCE of 13.1% can be achieved by adopting the spin-coating method, which is the top result for OSCs. More importantly, a blade-coated non-fullerene OSC processed with THF/IPA is demonstrated for the first time to obtain a promising PCE of 11.7%; even for the THF/IPA-processed large-area device (1.0 cm2 ) made by blade-coating, a PCE of 10.6% can still be maintained. These results are critical for the large-scale production of highly efficient OSCs in future studies.

Controlling synthesis of well-crystallized mesoporous TiO2 microspheres with ultrahigh surface area for high-performance dye-sensitized solar cells

Abstract: In this study, well-crystallized mesoporous anatase TiO2 spheres were prepared by hydrothermal treatment of the titanium diglycolate precursors. These spheres are submicrometer-sized and consist of packed nanocrystallites with diameters of ∼8 nm, and possess a specific surface area of 193 m2 g−1 and main pore sizes of ∼5 nm. We demonstrated that due to the large particle diameters and ultrahigh specific surface areas, mesoporous TiO2 microspheres can enhance the light harvesting within the photoanodes for dye-sensitized solar cells (DSSCs), and meanwhile, their good crystallinity and better interparticle connections caused by partially oriented attachment of primary particles result in the effective charge transport through the film of mesoporous TiO2 spheres. A high light-to-electricity conversion of 8.20% has been achieved, indicating a 40% increase in the conversion efficiency compared to the standard Degussa P25 photoanode.

Nanoporous high-entropy alloys for highly stable and efficient catalysts

Abstract: Controllably incorporating multiple immiscible metal elements into one single nanostructure has immeasurable technological and scientific potential, but it remains a challenge for the conventional bottom-up synthetic methods. Herein, we presented a general and scalable route to prepare multi-component nanostructured alloys referred to as nanoporous high-entropy alloys (np-HEAs) by combining bulk melting, fast cooling, and dealloying. To demonstrate this concept, we synthesized senary AlNiCuPtPdAu, octonary AlNiCuPtPdAuCoFe, and senary all-non-noble metal AlNiCuMoCoFe np-HEA with ligament sizes of ∼2–3 nm and precisely controlled composition by dealloying the designed precursor alloys. With a naturally formed thin oxide layer of spinel γ-Al2O3, AlNiCuPtPdAu np-HEA exhibited greatly enhanced high-temperature stability (up to 600 °C) and CO oxidation activity. Interestingly, with the removal of the surface oxide layer, np-HEA still showed good resistance to coarsening at 200 °C for 10 h due to its intrinsically low diffusivity originating from the multiple-principal-element mixing effect. For electrocatalysis, np-HEA with a low Pt loading amount exhibited 10 times the mass activity of Pt/C for oxygen reduction reaction and maintained 92.5% of its initial activity after 100k electrochemical cycles.