Design and Development of a Single-photon Laser and Infrared Common Aperture Optical System

Wu Hongbo,Zhang Xin,Tan Shuanglong,Liu Mingxin,Wang Lingjie,Yan Lei,Liu Yang,Shi Guangwei 한국광학회 2022 Current Optics and Photonics Vol.6 No.2

A single-photon laser and mid-wave infrared (MWIR) common aperture optical system was designed and developed to detect and range a long-distance civil aviation aircraft. The secondary mirror of the Ritchey-Chretien (R-C) optical system was chosen as a dichroic lens to realize the design of a common aperture system for the laser and MWIR. Point spread function (PSF) ellipticity was introduced to evaluate the coupling efficiency of the laser receiving system. A small aperture stop and narrow filter were set in the secondary image plane and an afocal light path of the laser system, respectively, and the stray light suppression ability of the small aperture stop was verified by modeling and simulation. With high-precision manufacturing technology by single point diamond turning (SPDT) and a high-efficiency dichroic coating, the laser/MWIR common aperture optical system with a φ300 mm aluminum alloy mirror obtained images of buildings at a distance of 5 km with great quality. A civil aviation aircraft detection experiment was conducted. The results show that the common aperture system could detect and track long-distance civil aviation aircraft effectively, and the coverage was more than 450 km (signal-tonoise ratio = 6.3). It satisfied the application requirements for earlier warning and ranging of long-range targets in the area of aviation, aerospace and ground detection systems.

Analysis of MHz 380V-12V DCX with low FoM device

Hongbo Shi,Xinke Wu,Mingchao Xia 전력전자학회 2019 ICPE(ISPE)논문집 Vol.2019 No.5

1MHz isolated high efficiency high power density DC/DC converter is critical for future industrial applications. The GaN devices have a better performance for such high frequency than silicon device of high breakdown voltage due to their much lower parasitic capacitance. The modeling of the primary switches conduction losses is built in this paper. Based on the model the relation between the NFoM (Rdson⋅Cotr) of primary devices and conduction loss is revealed, thus the lower voltage devices with lower FoM is adopted to implemented the experimental verification. Since the equivalent NFoM is independent of the device count of series connection and is decided by single device, an inputseries output-parallel structure prototype with multiple SRC DCX cells is implemented with low voltage MOSFETs. The 380V-12Vprototype achieves a peak efficiency of 98.3% and a power density of 810W/inch3 with multiple 60V MOSFETs.

Expression and Efficient Purification of Tag-cleaved Active Recombinant Human Insulin-like Growth Factor-II from Escherichia coli

Hongbo Li,Xiaoyan Hui,Peng Li,Aimin Xu,Shiwu Li,Shouguang Jin,Donghai Wu 한국생물공학회 2015 Biotechnology and Bioprocess Engineering Vol.20 No.2

Insulin-like growth factor-II (IGF2) is a growth factor for the control of cell proliferation and apoptosis. To explore the clinical use of human IGF2, an efficient method for production of a large amount of active recombinant hIGF2 is necessary. Human IGF2 cDNA was cloned into pET32 vector where it is under the control of an IPTGinducible T7 promoter. High level soluble thioredoxin (Trx)- hIGF2 fusion protein was produced at room temperature following IPTG induction, amounting up to 20% of the total soluble bacterial proteins. The recombinant TrxhIGF2 fusion protein was purified to an approximate 95% purity using Ni+-NTA affinity chromatography with an overall yield of 120 mg protein per liter of bacterial culture. After cleavage of the Trx fusion fragment by recombinant enterokinase, the tag-free recombinant hIGF2 protein (rhIGF2) was purified by passage through the Ni+-NTA affinity column again. Biological activity of the purified hIGF2 was determined by its ability to support NIH/3T3 cells proliferation and to activate AKT signaling pathways. Our results demonstrate that tag-free active rhIGF2 can easily be obtained for various applications from E. coli using the procedure described in this report.

Study on Low-cycle Fatigue Performance of Aluminum Alloy Temcor Joints

Yapeng Wu,Hongbo Liu,Zhi-Hua Chen,Yu Liu 대한토목학회 2020 KSCE Journal of Civil Engineering Vol.24 No.1

Aluminum alloy Temcor joints have been extensively applied to aluminum alloy latticed shells, but easily experience low-cycle fatigue under the effects of strong winds. In this paper, the low-cycle fatigue performance of the Temcor joints was studied by experimental researches, finite element simulations and theoretical analyses. Six kinds of displacement loads were selected and the low-cycle fatigue failure mechanism and fatigue life of the Temcor joints were studied through experimental research. Under the effect of the low-cycle reciprocating load, the bolt went through continuous brittle failure and the failure position was located at the junction between the screw root and the nut. Consistent with the experimental situations, the finite element model was established and the simulation results were compared well with the experimental results. Then, a prediction method for low-cycle fatigue life based on the local stress-strain method was attempted, and the finite element simulation method was employed to calculate the key parameters. The low-cycle fatigue life prediction results based on the local stress-strain method accorded well with the test results.

Influence of Driving Voltage on Starting Performance of High-Speed Permanent Magnet Synchronous Starter–Generator for Micro-gas Turbine

Qiu Hongbo,Wang Kun,Zou Xutian,Xiong Bin,Wu Xuanzong 대한전기학회 2021 Journal of Electrical Engineering & Technology Vol.16 No.6

The high-speed electrical machine as a critical power conversion unit in the micro gas turbine generation system needs to integrate the functions of starter and generator, which makes the control system of the machine more complex. In order to simplify the control system and improve the starting speed of the generation system with the help of the intrinsic starting ability of the machine, a high-speed starter–generator with multilayer composite solid rotor is proposed. The machine with the proposed solid rotor can realize self-start when it works in starting mode. Taking a 40 kW 20,000r/min high-speed permanent magnet machine as an example, the fi nite element model of the machine is established. The infl uence of driving voltage on the machine starting performance is analyzed and the start-up time, locked rotor parameters of the machine under diff erent driving voltages are further studied. Furthermore, in order to reveal the infl uence mechanism of driving voltage on the machine starting performance, the starting torque is decoupled and the infl uence of driving voltage on the decoupled torques is studied. Finally, the machine prototype is tested, and the correctness of the fi nite element model is verifi ed by comparing the experimental data with the fi nite element calculation data.

Influence of Sleeve Material and Sleeve Composite Structure on Performance of High-Speed Permanent Magnet Starter-Generator for Micro-Gas Turbine

Qiu Hongbo,Liu Ziyang,Xiong Bin,Zhao Qiang,Dong Yu,Wu Xuandong 대한전기학회 2022 Journal of Electrical Engineering & Technology Vol.17 No.4

When the high-speed permanent magnet starter-generator (PMSG) is operating, the permanent magnets will be aff ected by high centrifugal forces. It is necessary to add a sleeve to protect the rotor and interference fi t with the permanent magnet. However, the performance of the high-speed PMSG will be signifi cantly infl uenced by the electromagnetic characteristics of the sleeve material. In this paper, a high-speed permanent magnet starter-generator for the micro-gas turbine is used as an example, and the two-dimensional fi nite element model is established. The correctness of the model is verifi ed by comparing the experimental data with the calculated data. Taking 10,000 r/min as the ignition speed, the diff erences of motor starting performances when using diff erent sleeve materials are compared. Secondly, decoupling the complex coupling torque in the starting process, the infl uence of material electromagnetic characteristics on the asynchronous torque and braking torque is determined, and the infl uence mechanism of material electromagnetic characteristics on the torque characteristics of highspeed PMSG is revealed. In addition, the eff ects of the sleeve materials on the output performance and loss of the high-speed PMSG are determined, and infl uence mechanism is revealed. On the basis, a sleeve multiplexing scheme is proposed to improve the starting performance while reducing the eddy current losses in the generating state. The results of the study provide reference and theoretical value for the optimization of high-speed permanent magnet starter-generator.

Influence of Magnetic Slot Wedge on Parameter and Loss Distribution of High Voltage Induction Motor

Qiu Hongbo,Wang Kun,Liu Ziyang,Xiong Bin,Wu Xuandong 대한전기학회 2022 Journal of Electrical Engineering & Technology Vol.17 No.6

Owing to the stator open slot structure of the high-voltage motor, the magnetic field distribution in the motor will be uneven, and the performance of the motor will deteriorate. When the slots are embedded with magnetic material slot wedges, the magnetic field of the motor will be changed. In this article, taking a 10 kV/1000 kW high-voltage induction motor (HVIM) as the prototype, the two-dimensional finite element models are established, the eff ect of magnetic slot wedge (MSW) on HVIM was analyzed. First, by establishing the air-gap permeance function, the infl uence of magnetic slot wedge on the air gap magnetic field is analyzed, the influence mechanism of magnetic slot wedge on tooth harmonic magnetic field is revealed. In addition, the effect of magnetic slot wedge on excitation inductance, slot leakage resistance, and winding inductance of HVIM is analyzed in detail, the variation of parameters with different relative permeability of slot wedge is summarized, the changes in the motor starting performance had further discussed. Finally, the influence of the slot wedge permeability on motor losses is studied, the distribution of core loss is obtained by establishing the motor segmenting model, and the various mechanisms of core losses in different regions are revealed. The findings provide the guidelines and theoretical basis for the rational selection of magnetic slot wedges.

Evaluation of Soil Carbon and Nitrogen Transformation by Microbial Metabolism and New Microbial Legacy

Xudong Zhang,Hongbo He,Yeye Wu 한국토양비료학회 2014 한국토양비료학회 학술발표회 초록집 Vol.2014 No.6

How Do Microbial Metabolism and New Microbial Legacy Mediate Soil Carbon and Nitrogen Cycling?

Xudong Zhang,Hongbo He,Yeye Wu,Wei Zhang 한국토양비료학회 2014 한국토양비료학회 학술발표회 초록집 Vol.2014 No.6

Study on the progressive collapse resistance of CP-FBSP connections in LCFST frame structe

Qingqing Xiong,Wenbo Wu,Wang Zhang,Zhihua Chen,Hongbo Liu,Tiancheng Su 국제구조공학회 2022 Steel and Composite Structures, An International J Vol.44 No.3

When the vertical load-bearing members in high-rise structures fail locally, the beam-column joints play an important role in the redistribution of the internal forces. In this paper, a static laboratory test of three full-scale flush flange beam-reinforced connections with side and cover plates (CP-FBSP connection) with double half-span steel beams and single Lshaped columns composed of concrete-filled steel tubes (L-CFST columns) was conducted. The influence of the side plate width and cover plate thickness on the progressive collapse resistance of the substructure was thoroughly analyzed. The failure mode, vertical force-displacement curves, strain variation, reaction force of the pin support and development of internal force in the section with the assumed plastic hinge were discussed. Then, through the verified finite element model, the corresponding analyses of the thickness and length of the side plates, the connecting length between the steel beam flange and cover plate, and the vertical-force eccentricity were carried out. The results show that the failure of all the specimens occurred through the cracking of the beam flange or the cover plate, and the beam chord rotations measured by the test were all greater than 0.085 rad. Increasing the length, thickness and width of the side plates slightly reduced the progressive collapse resistance of the substructures. The vertical-force eccentricity along the beam length reduced the progressive collapse resistance of the substructure. An increase in the connecting length between the beam flange and cover plate can significantly improve the progressive collapse resistance of substructures.