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| 1 | New method for camera pose estimation based on line correspondence显示文摘The key technology of the measuring method of pose shaking of unstable platform based on CCD lies in the camera pose estimation.A new method for camera pose estimation based on line correspondence is put forward in this paper.First,two appropriate lines are selected in the space to establish a local coordinate system,the remaining lines form three-line sets with these two lines respectively and then the angle depth of the lines of the local coordinate system can be obtained by using the linearity of interpretation plane;then the invariance of included angle between spatial coordinate system and camera coordinate system during rigid transformation is used to establish a constraint equation set of angle depth of three lines similar to traditional P3P,and the corresponding angle depth of the third line in the set can be obtained linearly by variable substitution;finally,the rotation matrix can be expressed with quaternion and the pose parameters of camera in the space can be calculated by singular value decomposition(SVD).The static experiment and dynamic experiment verify the accuracy and stability of the algorithm and that the camera pose shocking is within 1°and the 3σ error is superior to 0.3′.The method in this paper can be directly used in the micro-vibration measurement of experimental platform and robot navigation and other fields and is of important theoretical significance and engineering application prospect. | LIU JinBo ZHANG XiaoHu LIU HaiBo YUAN Yun ZHU ZhaoKun YU QiFeng | 2013 | Science China(Technological Sciences)2013，56，11： | 11 |
| 2 | Videometric research on deformation measurement of large-scale wind turbine blades显示文摘Utilization of wind energy is a promising way to generate power,and wind turbine blades play a key role in collecting the wind energy effectively.This paper attempts to measure the deformation parameter of wind turbine blades in mechanics experiments using a videometric method. In view that the blades experience small buckling deformation and large integral deformation simultaneously, we proposed a parallel network measurement(PNM) method including the key techniques such as camera network construction,c... | Xiangyi Sun,Yun Yuan,~(a))Zhaokun Zhu,Xiaohu Zhang,and Qifeng Yu College of Aerospace and Materials Engineering,National University of Defense Technology,Changsha 410073, Hunan,China | 2011 | Theoretical & Applied Mechanics Letters2011，1，1： | 5 |
| 3 | Distinct roles of ASIC3 and TRPV1 receptors in electroacupuncture-induced segmental and systemic analgesia显示文摘 | Juanjuan Xin Yangshuai Su Zhaokun Yang Wei He Hong Shi Xiaoyu Wang Ling Hu Xiaochun Yu Xianghong Jing Bing Zhu | 2016 | Frontiers of Medicine2016，10，4： | 5 |
| 4 | Correction method for non-landing measuring of vehicle-mounted theodolite based on static datum conversion显示文摘During the non-landing measuring of vehicle mounted theodolite, especially under high-speed tracking measurement, the misalignment of theodolite's center of mass and spindle etc. will cause high-frequency vibration of theodolite platform, increase the observation error of targets and even unbelievable results. In this paper, a correction method of non-landing measuring of theodolite based on static datum conversion is presented, which can effectively improve the observation accuracy of theodolite. The CCD camera is fixed to the theodolite platform to calculate the gesture shaking quantity of theodolite platform in geodetic coordinate system through the real time imaging of static datum. The observation results of theodolite are corrected by using such shaking quantity. The experiment shows that the correction accuracy exceeds 10 s of arc. The intrinsic parameter calibration technology of camera based on stellar angular distance and absolute conic put forward in this paper can prevent the estimated error of extrinsic parameters influencing the intrinsic parameter calibration and improve the intrinsic parameter calibration accuracy; the static datum conversion technology can reduce the influence of installation error of camera and theodolite platform on gesture measuring of the platform. The simulation experiment shows that when the shaking range of the platform is less than 30 min of arc, the influence of the three-axis installation error of camera within 3deg on the accuracy of correction results is less than 8 s of arc. The method in this paper can be extended to and used in the field of gesture shaking measuring and micro-structure deformation of various unstable platforms, therefore it is of important theoretical research significance and has wide engineering application prospect. | LIU JinBo ZHANG XiaoHu LIU HaiBo YUAN Yun ZHU ZhaoKun YU QiFeng | 2013 | Science China(Technological Sciences)2013，56，9： | 5 |
| 5 | Observation of controllable tightly and loosely bound solitons with an all-fiber saturable absorber显示文摘A hybrid no-core fiber(NCF)–graded index multimode fiber(GIMF) structure is used as a saturable absorber(SA)for mode-locked laser operation. Such an SA supports various types of soliton outputs. By changing the cavity parameters, not only the spatiotemporal mode-locking states with a stable single pulse but also tightly and loosely bound solitons are generated. Single 35.5 pJ solitons centered at 1568.5 nm have a 4 nm spectral full-width at half-maximum and an 818 fs temporal duration. Tightly bound soliton pairs with continuously tunable wavelength from 1567.48 nm to 1576.20 nm, featured with an ~700 fs pulse train with a separation of 2.07 ps, have been observed by stretching the NCF-GIMF structured device. Meanwhile, several different pulse separations from 37.57 ps to 56.46 ps of loosely bound solitons have also been realized. The results provide help in understanding the nonlinear dynamics in fiber lasers. | TIANYU ZHU ZHAOKUN WANG D.N.WANG FAN YANG LIUJIANG LI | 2019 | Photonics Research2019，7，1： | 4 |
| 6 | Generation of wavelength-tunable and coherent dual-wavelength solitons in the C + L band by controlling the intracavity loss显示文摘A wavelength-tunable and dual-wavelength mode-locking operation is achieved in an Er-doped fiber laser using a hybrid no-core fiber graded index multimode fiber as the saturable absorber. In the tuning operation, continuously wavelength-tunable pulses with a tuning range of 46.7 nm, stable 3-dB bandwidth of around 5 nm, and pulse duration of ~850 fs are obtained by increasing the intracavity loss of a variable optical attenuator. In the dual-wavelength operation, the two solitons at different wavelengths demonstrate the characteristics of mutual coherence. By increasing the intracavity loss, the spectral spacing can be tuned from 11 to 33.01 nm while maintaining the coherence of the solitons. Such coherent solitons have high potential for applications in dual-comb frequency and multicolor pulses in nonlinear microscopy. | TIANYU ZHU ZHAOKUN WANG D.N.WANG FAN YANG LIUJIANG LI | 2019 | Photonics Research2019，7，8： | 2 |
| 7 | Removal of Cadmium from Aqueous Solutions by Adsorption on Granular Red Mud(GRM)显示文摘 | Zhu Chunlei Luan Zhaokun Wang Yanqiu | 2007 | Separation and Purification Technology2007，57，1： | 1 |
| 8 | Removal of cadmium from aqueous solutions by adsorption on granular red mud (GRM) 显示文摘 | Zhu Chunlei Luan Zhaokun Wang Yanqiu | 2007 | Separation and Purification Technology2007，57，1： | 1 |
| 9 | Competitive adsorption of Pb 2+ , Cu 2+ and Cd 2+ ions from aqueous solutions by multiwalled carbon nanotubes显示文摘 | Yan-Hui Li Jun Ding Zhaokun Luan Zechao Di Yuefeng Zhu Cailu Xu Dehai Wu Bingqing Wei | 2003 | Carbon2003，，14： | 1 |
| 10 | Graded index fiber as an all-fiber saturable absorber for large energy conventional soliton and dissipative soliton generation显示文摘In this work, we investigate the possibility of achieving nanojoule level pulse energy in an all-fiber Er-doped oscillator by using a graded index multimode fiber(GIMF) as the saturable absorber(SA). This GIMF-based SA demonstrates the desirable characteristics of high-power tolerance, large modulation depth of 29.6%, and small saturation fluence of7.19 × 10^-3μJ∕cm^2, which contribute to the high-energy soliton generation. In the experiments, the oscillator generates stable ultrafast pulse trains with high pulse energy/average output power up to 13.65 nJ/212.4 m W in the anomalous regime and 6.25 nJ/72.5 m W in the normal regime, which are among the highest energy/average output power values achieved by all-fiber Er lasers. The results obtained demonstrate that the GIMF-based SA can be used as an effective photonic device for high-energy wave-breaking free pulse generation. | ZHAOKUN WANG JIKAI CHEN TIANYU ZHU D.N.WANG FENG GAO | 2019 | Photonics Research2019，7，11： | 1 |
| 11 | Flow field and convective heat transfer of smallscale Taylor-Couette flow induced by end leakage显示文摘More and more researchers have paid attention to Taylor-Couette flow whose axial dimension is much larger than other dimensions.However,featured by the limited axial length of the bearing,its flow field and convective heat transfer between the rotator and the stator are highly conglutinated with the leakage at the end of the clearance.An investigation was conducted on the flow field and convective heat transfer of small-scale Taylor-Couette flow induced by end leakage through means of numerical simulation and experimental measurement.The static pressure and temperature of the stator were captured by a micromanometer and a time-resolved infrared camera,respectively.Large Eddy Simulation(LES)was performed to reveal the instantaneous and mean flow field of the shearing flow.Results show that the flow field and convective heat transfer are tightly associated with the presence of end leakage.As approaching the end of the clearance,the flow is dominated by the axial flow induced by the end leakage,and then a series of Taylor vortices gradually distorts and tilts as moving downstream.Along the angular direction,the maximum and minimum static pressures take place near minimum clearance height,respectively.The static pressure along the angular direction and the axial velocity near the minimum clearance height as well as the Nusselt number increase with increases of the rotational Reynolds number and the eccentricity ratio while decreasing with an increase of the dimensionless clearance height.Both natural convection by buoyancy and forced convection by the shearing flow play a significant role in convective heat transfer.Compared with classic Taylor-Couette flow,the occurrence of leakage decreases the maximum static pressure while increasing the minimum static pressure.The formation and evolution of the Taylor vortex are dominated by the axial flow. | Jingyang ZHANG Zhaokun MA Yuan LIU Guiping ZHU Yuanwei LYU | 2023 | Chinese Journal of Aeronautics2023，36，11： | 0 |
| 12 | Effect of aluminum on microstructure and magnetic properties of sintered Nd-Fe-B magnets processed by grain boundary diffusion of Tb-Al显示文摘The grain boundary diffusion process(GBDP)of Tb can improve the coercivity of sintered Nd-Fe-B magnets.In this study,the effect of AI on the diffusion of Tb in the GBDP was investigated.The content of diffused Tb-Al was precisely controlled by adjusting the magnetron sputtering process.The Tb equivalent of Al was also studied.Results show that AI promotes the diffusion of Tb deeper into the magnet,reducing the thickness of the shell in the core-shell structure.This study is helpful for further developing the process,reducing the consumption of heavy rare earth elements(Tb),and improving the coercivity of sintered Nd-Fe-B magnets. | Tinghui Wang Zhaokun Ma Qihang Zhu Lijing Yang Baosheng Liu Yu Zhao Cheng Xu Bizhang Zheng Fangqin Hu Jianzhong Li Qingfang Huang Zhenlun Song | 2023 | Journal of Rare Earths2023，41，5： | 0 |
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