Harbin, China

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.

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Harbin Institute of Technology | Date: 2014-12-26

Aircraft engine rotors traditionally have low coaxiality after assembly. This is solved by the methods and devices described herein, having advantages that the rotors have high coaxiality after assembly, reduced vibration, easy installation, high flexibility, and improved engine performance. A measurement method and device use an air flotation rotary shaft system determining a rotary reference. An induction synchronizer determines angular positioning of a turntable. Using a four probe measurement device, a radial error of a rotor radial assembly surface and an inclination error of an axial mounting surface are extracted and an influence weight value of the rotor on the coaxiality of assembled rotors is obtained. All rotors required for assembly are measured and an influence weight value of each on the coaxiality of the assembled rotors is obtained. Vector optimization is performed on the weight value of each rotor and an assembly angle of each rotor is obtained.

A five-degree-of-freedom adjustment and positioning method and apparatus for assembly/measurement of rotor and stator of an aircraft engine; said method comprises adjusting a plane motion and a rotation of a tested piece through composite motion comprising five degrees of freedom: a 360 rotatory motion around a Z axis, a plane motion along an X axis and a plane motion along a Y axis, a rotatory motion around the X axis and a rotatory motion around the Y axis; said apparatus comprises: a clamping mechanism (1), a turning platform component (A), a translational platform component (B) and a rotational platform component (C). The present invention designs a five-degree-of-freedom adjustment and positioning method and apparatus having properties of large load bearing, high precision and high stiffness, thus improving assembly efficiency and measurement accuracy of the aircraft engine.

Harbin Institute of Technology | Date: 2015-04-10

A high-power bi-directional non-recovery spring magnetic valve including permanent magnets has an upper magnetic circuit part and lower magnetic circuit part symmetrically disposed and connected together via an armature connection rod and a housing connection ring, the upper magnetic circuit part comprises an upper iron core, an upper housing, an upper coil, an upper annular permanent magnet, an upper yoke iron and an upper push rod, the lower magnetic circuit part comprises a lower iron core, a lower housing, a lower coil, a lower annular permanent magnet, a lower yoke iron and a lower push rod. The magnetic valve comprising permanent magnets realizes bistable-state magnetic retaining, and has an adjustable retaining force for permanent magnet adjustment, quick response, and high output force.

A method for measuring a dip angle of oppositely crossly placed paired quartered ring-quartered circle nested polar plates. An annular coplanar capacitance measuring head of a sensor unit consists of four quarter round metal plates and four quarter circular-ring-shaped metal plates, the eight metal plates are coplanar and concentric with one another, and a quarter round metal plate and a quarter circular-ring-shaped metal plate corresponding to the same sector angle form a capacitor. Two annular coplanar capacitance measuring heads are arranged on two round insulating substrates, the two round insulating substrates are used as two bottom surfaces of a cylindrical container, the cylindrical container is transversely arranged, and an insulating liquid equal to volume of the cylindrical container is injected into the cylindrical container in a sealing manner. Potential leads extract potentials of the sixteen metal plates and are connected to an input end of a capacitance measuring unit, and the capacitance measuring unit is connected to a dip measuring unit. When the cylindrical container tilts, the relative positions of the two annular coplanar capacitance measuring heads and the insulating liquid are changed, and a dip angle value can be calculated by measuring the change of a capacitance value. Also disclosed is a device for measuring a dip angle of oppositely crossly placed paired quartered ring-quartered circle nested polar plates.

An optical window based on an array of rings and sub-rings having a triangular and orthogonal mixed distribution is suited for electromagnetic shielding. The array has metal rings of the same diameter acting as basic rings closely arranged according to an equilateral triangular and two-dimensional orthogonal square mixed arrangement and is loaded on an optical window transparent substrate surface. Adjacent basic rings are connected externally tangentially. Metal sub-rings are arranged within each basic ring and connected thereto internally tangentially. Each basic ring and its sub-rings constitute a basic unit. At tangential connection locations of the rings, wires overlap or metal is provided to ensure reliable electrical connections between connected rings, thus all rings are conductive. The metal grid structure significantly reduces non-uniformity of grid high-order diffracted light intensity distribution, thereby causing stray light distribution caused by diffraction to be more uniform and imaging to be less affected.

Optical windows based on a multi-period master-slave nested ring array of concentric rings are suited for electromagnetic shielding. A metal grid of the ring array has basic rings, concentric sub-ring pairs, secondary sub-rings, filling rings, concentric modulation ring pairs, and modulation sub-rings. Basic rings and concentric modulation ring pairs form a two-dimensional orthogonal array. External rings of concentric modulation ring pairs are externally tangentially connected to basic rings. Concentric sub-ring pairs and filling rings are arranged within basic rings, secondary sub-rings are arranged within concentric sub-ring pairs, and modulation sub-rings are arranged within concentric modulation ring pairs. Where rings are tangentially connected, wires overlap or metal ensures reliable electrical connections between connected rings, thus all rings are conductive. The metal grid structure significantly reduces non-uniformity of grid high-order diffracted light intensity distribution, causing stray light distribution caused by diffraction to be more uniform and imaging to be less affected.

Harbin Institute of Technology | Date: 2017-03-29

A fast-response thermoplastic shape-memory polyimide and a preparation method thereof, related to a polyimide and a preparation method thereof. The present invention aims to solve the problem in high-temperature conditions of slow shape recovery poor stability, and poor mechanical properties of a shape-memory polymer prepared by utilizing an existing method. The structural formula of the polyamide of the present invention is as represented by formula (I). The preparation method is: 1. preparation of a diamine solution; 2. preparation of an anhydride-terminated high molecular weight polyamic acid; 3. preparation of a viscous sol-gel; and, 4. preparation of the thermoplastic shape-memory polyimide. The thermoplastic shape-memory polyimide prepared per the present invention is provided with a very fast shape recovery rate and improved shape-memory effect. The present invention is applicable in the field of polyimide preparation.

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.

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.

Zhu Q.,Harbin Institute of Technology | Pan Q.,Harbin Institute of Technology
ACS Nano | Year: 2014

Immobilization of various nanoparticles onto complex 2D or 3D macroscopic surface is an important issue for nanotechnology, but the challenge remains to explore a facile, general and environmentally friendly method for achieving this goal. Taking inspiration from the adhesion of marine mussels, we reported here that oxide nanoparticles of different compositions and sizes were directly and robustly anchored on the surface of monolithic foams ranging from polymer to metals in an aqueous solution of dopamine. The effective immobilization of the nanoparticles was strongly dependent on the oxidation of dopamine, which could be tuned by either pH or by adding n-dodecanethiol. Interestingly, the thiol addition not only allowed the immobilization to take place in a wide pH range, but also led to superhydrophobicity of the resulting foams. Application of the superhydrophobic foams was illustrated by fast and selective collecting oils from water surface. Because catecholic derivatives exhibit high affinity to a variety of substances, the present strategy might be extendable to fabricate hybrid nanomaterials desirable for self-cleaning, environmental protection, sensors and catalysts, and so forth. © 2014 American Chemical Society.

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