Harbin Institute of Technology

About: Harbin Institute of Technology is a education organization based out in Harbin, China. It is known for research contribution in the topics: Microstructure & Control theory. The organization has 88259 authors who have published 109297 publications receiving 1603393 citations. The organization is also known as: HIT.

Multiple solutions for nonhomogeneous Schrödinger–Kirchhoff type equations involving the fractional p -Laplacian in $${\mathbb {R}}^N$$ R N

Abstract: In this paper we investigate the existence of multiple solutions for the nonhomogeneous fractional p-Laplacian equations of Schrodinger–Kirchhoff type $$\begin{aligned} M\left( \iint _{R^{2N}}\frac{|u(x)-u(y)|^p}{|x-y|^{N+ps}}dxdy\right) (-\varDelta )^s_pu+V(x)|u|^{p-2}u=f(x,u)+g(x) \end{aligned}$$ in $${\mathbb {R}}^N$$ , where $$(-\varDelta )^s_p$$ is the fractional p-Laplacian operator, with $$0

Magnetically recoverable core-shell nanocomposites with enhanced photocatalytic activity.

Abstract: Core-shell structured Fe(3)O(4)/SiO(2)/TiO(2) nanocomposites with enhanced photocatalytic activity that are capable of fast magnetic separation have been successfully synthesized by combining two steps of a sol-gel process with calcination The as-obtained core-shell structure is composed of a central magnetite core with a strong response to external fields, an interlayer of SiO(2), and an outer layer of TiO(2) nanocrystals with a tunable average size The convenient control over the size and crystallinity of the TiO(2) nanocatalysts makes it possible to achieve higher photocatalytic efficiency than that of commercial photocatalyst Degussa P25 The photocatalytic activity increases as the thickness of the TiO(2) nanocrystal shell decreases The presence of SiO(2) interlayer helps to enhance the photocatalytic efficiency of the TiO(2) nanocrystal shell as well as the chemical and thermal stability of Fe(3)O(4) core In addition, the TiO(2) nanocrystals strongly adhere to the magnetic supports through covalent bonds We demonstrate that this photocatalyst can be easily recycled by applying an external magnetic field while maintaining their photocatalytic activity during at least eighteen cycles of use

Upconversion Emission Enhancement in Yb3+/Er3+-Codoped Y2O3 Nanocrystals by Tridoping with Li+ Ions

Abstract: We demonstrate that tridoping with Li+ ions enhances the visible green and red upconversion (UC) emissions in Er3+/Yb3+-codoped Y2O3 nanocrystals by up to half of the bulk counterpart, i.e., about 2 orders of magnitude higher than previous results. X-ray diffraction and decay time investigations give evidence that tridoping with Li+ ions can tailor the local crystal field of the Y2O3 host lattice. Theoretical calculations illustrate well that a significant UC intensity enhancement arises from the synthesized tailoring effect induced by the Li+ ions, which increase lifetimes in the intermediate 4I11/2 (Er) and 2F5/2 (Yb) states, increase optically active sites in the Y2O3 host lattice, and dissociate the Yb3+ and Er3+ ion clusters in the nanocrytals. The general theoretical description of the visible UC radiations shows that the Yb3+ ion sensitization and the tailoring effect induced by the Li+ ions are two independent enhancement mechanisms, which is expected to lead to an increasing number of photonic an...

Carbon Nanofibers and Their Composites: A Review of Synthesizing, Properties and Applications

Abstract: Carbon nanofiber (CNF), as one of the most important members of carbon fibers, has been investigated in both fundamental scientific research and practical applications. CNF composites are able to be applied as promising materials in many fields, such as electrical devices, electrode materials for batteries and supercapacitors and as sensors. In these applications, the electrical conductivity is always the first priority need to be considered. In fact, the electrical property of CNF composites largely counts on the dispersion and percolation status of CNFs in matrix materials. In this review, the electrical transport phenomenon of CNF composites is systematically summarized based on percolation theory. The effects of the aspect ratio, percolation backbone structure and fractal characteristics of CNFs and the non-universality of the percolation critical exponents on the electrical properties are systematically reviewed. Apart from the electrical property, the thermal conductivity and mechanical properties of CNF composites are briefly reviewed, as well. In addition, the preparation methods of CNFs, including catalytic chemical vapor deposition growth and electrospinning, and the preparation methods of CNF composites, including the melt mixing and solution process, are briefly introduced. Finally, their applications as sensors and electrode materials are described in this review article.