The Harbin Institute of Technology is a research university and a member of the C9 League in China consisting of three campuses, which nearly span the country from north to south: the Harbin campus in Heilongjiang Province, the Weihai campus in Shandong Province and the Shenzhen graduate school in Guangdong Province.HIT undertakes research and numerous projects covered by official secrets which may have a bearing on its international ranking, although it is widely recognized as one of the top universities in the country, especially when it comes to local science and engineering league tables. HIT is one of only ten universities in the world that have designed, built, and launched their own satellites . It made the largest contribution to the success of the Shenzhou series spacecraft and Kuaizhou series spacecraft. One minor planet is named after the Harbin Institute of Technology and nicknamed "Hagongda Star" by the International Astronomical Union for HIT's achievements in science and engineering. Wikipedia.
Leonov G.A.,Harbin Institute of Technology
Physics Letters, Section A: General, Atomic and Solid State Physics | Year: 2012
The general method for proving the existence of homoclinic trajectories in dissipative systems is developed. The applications of this method to Lorenz-like systems: Lorenz, Shimizu-Morioka, Lu and Chen systems are demonstrated. A criterion for the existence of a homoclinic trajectory within a given family of differential equations (Fishing principle) is presented. New numerical algorithm for the approximation of a homoclinic point in parameters space is constructed. The comparison with Kaplan-Yorke and Shilnikov results is made. © 2012 Elsevier B.V.
Li F.-M.,Harbin Institute of Technology
International Journal of Engineering Science | Year: 2012
The active aeroelastic flutter properties of supersonic plates are investigated by using the piezoelectric material. The piezoelectric material has been extensively used for the active vibration control of engineering structures. In this paper, the piezoelectric material is further used to improve the flutter characteristics of the supersonic plates. The equation of motion of the plate and piezoelectric material system is obtained by Hamilton's principle with the assumed mode method. The supersonic piston theory is used to evaluate the aerodynamic load. By applying an appropriate external control voltage to activate the piezoelectric material, a displacement and acceleration feedback control strategy is used to obtain the active stiffness and active mass. Solving the eigenvalue problem of the equation of motion, the natural frequencies and damping ratios of the structural system are obtained. Furthermore, the aeroelastic flutter bounds are calculated, and the effects of feedback control gains on the active aeroelastic flutter characteristics of the structure are analyzed in detail. From the numerical results it is seen that the active stiffness and active mass have prominent effects on the flutter characteristics of the supersonic plates. The aeroelastic flutter properties can be greatly improved by introducing the active stiffness and active mass into the supersonic plate with the piezoelectric patch. With the increase of the feedback control gains, the active aeroelastic flutter properties for the lower order modes of the supersonic plate are gradually improved. © 2011 Elsevier Ltd. All rights reserved.
Chen N.,Harbin Institute of Technology |
Pan Q.,Harbin Institute of Technology
ACS Nano | Year: 2013
Ultralow-density (<10 mg cm-3) materials have many important technological applications; however, most of them were fabricated using either expensive materials or complicated procedures. In this study, ultralight magnetic Fe2O3/C, Co/C, and Ni/C foams (with a density <5 mg cm-3) were fabricated on the centimeter scale by pyrolyzing commercial polyurethane sponge grafted with polyelectrolyte layers based on the corresponding metal acrylate at 400 C. The ultralight foams consisted of 3D interconnected hollow tubes that have a diameter of micrometer and nanoscale wall thickness, forming hierarchical structures from macroscopic to nanometer length scales. More interesting was that the wall thickness and morphology of the microtubes could be tuned by controlling the concentrations of acrylic acid and metallic cations. After modification with low-surface-energy polysiloxane, the ultralight foams showed superhydrophobicity and superoleophilicity, which quickly and selectively absorbed a variety of oils from a polluted water surface under magnetic field. The oil absorption capacity reached 100 times of the foams' own weight, exhibiting one of the highest values among existing absorptive counterparts. By controlling the composition and conformation of the grafted polyelectrolyte layers, the present approach is extendable to fabricate a variety of ultralow-density materials desirable for absorptive materials, electrode materials, catalyst supports, etc. © 2013 American Chemical Society.
Shi L.,Harbin Institute of Technology |
Xia W.,Harbin Institute of Technology
Chemical Society Reviews | Year: 2012
The functionalization of C-H bonds and the visible light photoredox catalysis represent two prominent challenges in organic chemistry. In this regard, the combination of visible-light catalysis and C-H bond functionalization adjacent to a tertiary amine has been successfully developed in the past three years. In this tutorial review, we aim to give a brief overview of this issue and state the main results obtained in the reactions. This journal is © The Royal Society of Chemistry 2012.
Sun X.Y.,Harbin Institute of Technology
Advanced Materials | Year: 2014
In perovskite/spinel self-assembled oxide nanocomposites, the substrate surface plays a dominant role in determining the final morphology. Topgraphic features, such as pits and trenches, are written in the substrate using either Focused Ion Beam or wet etching through a block co-polymer mask. These features are effective at templating the self-assembly, resulting in a wide range of attainable nano-assemblies. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.