Harbin Engineering University

About: Harbin Engineering University is a education organization based out in Harbin, Heilongjiang, China. It is known for research contribution in the topics: Control theory & Computer science. The organization has 31149 authors who have published 27940 publications receiving 276787 citations. The organization is also known as: HEU.

Hydrothermal synthesis of carbon nanotube/cubic Fe3O4 nanocomposite for enhanced performance supercapacitor electrode material

Abstract: Carbon nanotube/Fe3O4 (CNT/Fe3O4) nanocomposite with well-dispersed Fe3O4 nano-cubes inlaid on the surfaces of carbon nanotubes, was synthesized through an easy and efficient hydrothermal method. The electrochemical behaviors of the nanocomposite were analyzed by cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and chronopotentiometry in 6 M KOH electrolyte. Results demonstrated that CNT as the supporting material could significantly improve the supercapacitor (SC) performance of the CNT/Fe3O4 composite. Comparing with pure Fe3O4, the resulting composite exhibited improved specific capacitances of 117.2 F/g at 10 mA/cm2 (3 times than that of pure Fe3O4), excellent cyclic stability and a maximum energy density of 16.2 Wh/kg. The much improved electrochemical performances could be attributed to the good conductivity of CNTs as well as the anchored Fe3O4 particles on the CNTs.

Development and missions of unmanned surface vehicle

Abstract: The navy and other Department of Defense organizations are increasingly interested in the use of unmanned surface vehicles (USVs) for a variety of missions and applications. The term USV refers to any vehicle that operates on the surface of the water without a crew. USVs have the potential, and in some cases the demonstrated ability, to reduce risk to manned forces, provide the necessary force multiplication to accomplish military missions, perform tasks which manned vehicles cannot, and do so in a way that is affordable for the navy. A survey of USV activities worldwide as well as the general technical challenges of USVs was presented below. A general description of USVs was provided along with their typical applications. The technical challenges of developing a USV include its intelligence level, control, high stability, and developmental cost reduction. Through the joint efforts of researchers around the world, it is believed that the development of USVs will enter a new phase in the near future, as USVs could soon be applied widely both in military and civilian service.

$\mathsf{LightChain}$ : A Lightweight Blockchain System for Industrial Internet of Things

Abstract: While the intersection of blockchain and Industrial Internet of Things (IIoT) has received considerable research interest lately, the conflict between the high resource requirements of blockchain and the generally inadequate performance of IIoT devices has not been well tackled. On one hand, due to the introductions of mathematical concepts, including Public Key Infrastructure, Merkle Hash Tree, and Proof of Work (PoW), deploying blockchain demands huge computing power. On the other hand, full nodes should synchronize massive block data and deal with numerous transactions in peer-to-peer network, whose occupation of storage capacity and bandwidth makes IIoT devices difficult to afford. In this paper, we propose a lightweight blockchain system called LightChain , which is resource-efficient and suitable for power-constrained IIoT scenarios. Specifically, we present a green consensus mechanism named Synergistic Multiple Proof for stimulating the cooperation of IIoT devices, and a lightweight data structure called LightBlock to streamline broadcast content. Furthermore, we design a novel Unrelated Block Offloading Filter to avoid the unlimited growth of ledger without affecting blockchain's traceability. The extensive experiments demonstrate that LightChain can reduce the individual computational cost to 39.32% and speed up the block generation by up to 74.06%. In terms of storage and network usage, the reductions are 43.35% and 90.55%, respectively.

Electrospinning Preparation and Drug‐Delivery Properties of an Up‐conversion Luminescent Porous NaYF4:Yb3+, Er3+@Silica Fiber Nanocomposite

Abstract: Up-conversion (UC) luminescent porous silica fibers decorated with NaYF(4):Yb(3+), Er(3+) nanocrystals (NCs) (denoted as NaYF(4):Yb(3+), Er(3+)@silica fiber) are prepared by the electrospinning process using cationic surfactant P123 as a template. Monodisperse and hydrophobic oleic acid capped beta-NaYF(4): Yb(3+), Er(3+) NCs are prepared by thermal decomposition methodology. Then, these NCs are transferred into aqueous solution by employing cetyltrimethylammonium bromide (CTAB) as secondary surfactant. The water-dispersible beta-NaYF(4):Yb(3+), Er(3+) NCs are dispersed into precursor electrospinning solution containing P123 and tetraethyl orthosilicate (TEOS), followed by preparation of precursor fibers via electrospinning. Finally, porous alpha-NaYF(4):Yb(3+), Er(3+)@silica fiber nanocomposites are obtained after annealing the precursor fibers containing beta-NaYF(4):Yb(3+), Er(3+) at 550 degrees C. The as-prepared alpha-NaYF(4):Yb(3+), Er(3+)@silica fiber possesses porous structure and UC luminescence properties simultaneously. Furthermore, the obtained nanocomposites can be used as a drug delivery host carrier and drug storage/release properties are investigated, using ibuprofen (IBU) as a model drug. The results indicate that the IBU-loaded alpha-NaYF(4):Yb(3+), Er(3+)@silica fiber nanocomposites show UC emission of Er(3+) under 980 nm NIR laser excitation and a controlled release property for IBU. Meanwhile, the UC emission intensity of IBU-alpha-NaYF(4):Yb(3+), Er(3+)@silica fiber system varies with the released amount of IBU.