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Effect of Heat Treatment Process on Properties of 1000 MPa Ultra-High Strength Steel

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Journal of Iron and Steel Research International 2011年第2期18卷 64-69页

作者： YU Wei QIAN ya-jun wu Hui-bin yaNG Yue-hui Metallurgical Engineering Institute University of Science and Technology Beijing Beijing 100083 China

Two types of steel, C-Mn-CrMo B microalloyed steel and C-Mn-Mo-Nb-Cu-B microalloyed steel, are designed to develop 1000 MPa ultra high strength steel. Two kinds of processes, thermomeehanical controlled process （TMCP） combined with traditional off-line quenching and tempering （QT） process versus controlled rolling process （CR） combined with direct quenching and tempering （DQ＋T） process, are applied. The effect of heat treatment processing mode on the microstructure and mechanical properties is studied. The relationship between microstructure and mechanical properties is investigated by SEM and TEM. After tempering at 450 to 550 ℃ for 1 h, the steel produced by TMCP＋QT process shows combination of excellent strength and low temperature toughness. The yield strength is above 1 000 MPa, elongation above 15% and impact energy at -40 ℃ more than 30 J. After tempering at 450 ℃, a large number of ε-Cu particles precipitated in C-Mn-Mo-Nb-Cu-B steel produced by CR＋DQ＋T process lead to a significant increase in yield strength. And after tempering at 500 to 600 ℃, the yield strength of the steel is further improved to 1 030 MPa because of precipitates, such as nitride or carbide of niobium, carbide of molybedenum and vanadium. When the tempering temperature is increased above 620 ℃, the yield strength is still higher than 1 000 MPa and elongation is above 20% and impact energy at --40 ℃ is more than 35 J. After tempering at above 500 ℃, the toughness of the steel treated by TMCP＋QT process is superior to that of steel by CR＋DQ＋T process.

关键词： heat treatment high strength steel microstructure mechanical property

Spatial Distribution of HOCN Around Sagittarius B2

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Research in Astronomy and Astrophysics 2022年第3期22卷 61-71页

作者： Si-Qi Zheng Juan Li jun-Zhi Wang Feng Gao ya-jun wu Shu Liu Shang-Huo Li Shanghai Astronomical Observatory Chinese Academy of SciencesShanghai 200030China Key Laboratory of Radio Astronomy Chinese Academy of SciencesNanjing 210033China University of Chinese Academy of Sciences Beijing 100049China Hamburger Sternwarte Universitaet HamburgGojenbergsweg 112D-21029HamburgGermany National Astronomical Observatories Chinese Academy of SciencesBeijing 100101China Korea Astronomy and Space Science Institute 776 Daedeokdae-roYuseong-guDaejeon 34055Republic of Korea

HOCN and HNCO abundance ratio in molecular gas can tell us the information of their formation *** performed high-sensitivity mapping observations of HOCN,HNCO,and HNC^(18)O lines around Sagittarius B2(Sgr B2)with the IRAM 30 m telescope at the 3 mm *** 4_(04)-3_(03)and HOCN 4_(04)-3_(03)are used to obtain the abundance ratio of HNCO to *** ratio of HNCO 4_(04)-3_(03)to HNC^(18)O 4;-3;is used to calculate the optical depth of HNCO 4_(04)-3_(03).The abundance ratio of HOCN and HNCO is observed to range from 0.4%to0.7%toward most positions,which agrees well with the gas-grain ***,the relative abundance of HOCN is observed to be enhanced toward the direction of Sgr B2(S),with HOCN to HNCO abundance ratio of~0.9%.The reason for that still needs further *** on the intensity ratio of HNCO and HNC^(18)O lines,we updated the isotopic ratio of;O/;O to be 296±54 in Sgr B2.

关键词： ISM:abundances ISM:interstellar clouds ISM:interstellar molecules

Different approaches for treating myopic choroidal neovascularization:a network Meta-analysis

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International Journal of Ophthalmology(English edition) 2023年第12期16卷 2105-2116页

作者： ya-jun wu Yu-Liang Feng Jia-Song yang Hua Fan Wen-Sheng Li Aier School of Ophthalmology Central South UniversityChangsha 410000Hunan ProvinceChina Department of Ophthalmology Shanghai Aier Eye HospitalShanghai 200235China Shanghai Aier Eye Institute Shanghai 200235China

AIM:To evaluate the efficacy of intravitreal injection of anti-vascular endothelial growth factor(anti-VEGF),photodynamic therapy(PDT),and laser treatment(LT)for anatomical and functional improvement in myopic choroidal neovascularization(mCNV)***:Two researchers independently searched PubMed,Cochrane Library,Web of Science,and other databases to screen studies comparing best-corrected vision acuity(BCVA)and foveal center thickness(FCT)changes after mCNV ***-treatment chorioretinal atrophy(CRA)is a secondary outcome *** retrieval time limit is from the database construction to January 30,***:A total of 1072 eyes in 16 articles were *** the RCTs,intravitreal bevacizumab(IVB)and intravitreal ranibizumab(IVR)were superior to PDT(MD=0.18,95%CI:0.02,0.40,MD=0.18,95%CI:0.01,0.42)in improving BCVA of mCNV patients(P<0.05).The relative effectiveness in improving BCVA,from high to low,appeared to be IVR,intravitreal aflibercept(IVA),IVB,LT,PDT,and sham first followed by IVA(Sham/IVA).While improving the FCT from high to low was IVA,IVR,IVB,*** retrospective studies,the results of BCVA after long-term treatment showed that all the therapeutic effects from high to low was IVA,intravitreal conbercept(IVC),IVR,IVB,IVB/IVR,PDT with IVB/IVR,*** effect of improving FCT was IVA,IVR,IVC,PDT,and IVB from high to *** in the effects of improving CRA,the IVB appeared to be higher than IVR,while the PDT was the smallest,but none of the differences in the results were statistically ***:Anti-VEGF has the best effect on longterm vision improvement in mCNV patients,using IVB or IVR alone to treat mCNV may be better than IVB or IVR combined with *** is no significant difference in the improvement of visual acuity,macular edema,and CRA in mCNV patients treated with any different anti-VEGF drugs.

关键词： myopic choroidal neovascularization aflibercept bevacizumab conbercept laser treatment ranibizumab photodynamic therapy

Vitrectomy with internal limiting membrane peeling versus its flap insertion for macular hole in high myopia: a Meta-analysis

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International Journal of Ophthalmology(English edition) 2020年第1期13卷 141-148页

作者： ya-jun wu Jie Rao Kang-Rui wu Na wu Yi Cheng Xiao-Xuan Xu Li yan Yi Shao Yu Tian Xiao-Rong wu Department of Ophthalmology the First Affiliated Hospital of Nanchang UniversityNanchang 330006Jiangxi ProvinceChina Department of Ophthalmology the Second Xiangya HospitalCentral South UniversityChangsha 410008Hunan ProvinceChina

AIM: To compare the anatomic and functional outcomes between vitrectomy with internal limiting membrane(ILM) peeling and internal ILM flap insertion technique for high myopia macular hole(MH).METHODS: Pub Med, Cochrane Library, EMBASE, and CNKI were systematically searched, and all studies involved MH were included. The closure rate of MH and the postoperative best-corrected visual acuity(BCVA) at 6 mo after the initial surgery were the primary measures. All statistical tests were performed in Review Manager ***: Five studies that included 151 eyes of 151 patients were finally included, all of which were retrospectively comparative studies. Between the pars plana vitrectomy(PPV) with ILM peeling surgery and the ILM insertion technique, the latter had significantly better efficacy with respect to the closure rate of MH(OR=21.32, 95%CI=7.25-62.67, P<0.001);However, regarding BCVA at 6 mo after the initial surgery in MH, there was no statistical significance between the groups(OR=-0.04, 95%CI=-0.22-0.14, P=0.66). In addition, regarding the rate of retinal reattachment after the initial surgery, the two different methods were not significantly different(OR=2.22, 95%CI=0.34-14.32, P=0.4).CONCLUSION: Both ILM peeling and ILM insertion technique could significantly improve anatomic outcomes of MH in high myopia with or without retinal detachment(RD), and anatomic outcomes are more effective. However, there is no statistical significance in BCVA at 6 mo after the initial surgery in MH, or in the rate of retinal reattachment after the first surgery, between the two methods.

关键词： macular hole high myopia best-corrected visual acuity retinal attachment Meta-analysis

A novel Doppler frequency measurement method based on the closed-loop signal correlation for deep space exploration

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Research in Astronomy and Astrophysics 2021年第9期21卷 75-82页

作者： Tao Deng Mao-Li Ma Qing-Bao He Qing-Hui Liu ya-jun wu Xin Zheng Shanghai Astronomical Observatory Chinese Academy of SciencesShanghai 200030China University of Chinese Academy of Sciences Beijing 100049China Southern University of Science and Technology Shenzhen 518055China

In deep space exploration,it is necessary to improve the accuracy of frequency measurement to meet the requirements of precise orbit determination and various scientific studies.A phase detector is one of the key modules that restricts the tracking performance of phase-locked loop(PLL).Based on the phase relationship between adjacent signals in the time domain,a novel phase detector is presented to replace the arctangent phase *** new PLL,which is a closed loop signal correlation algorithm,shows good performance in tracking signals with high precision and the tracking accuracy of frequency of1 second integration is close to Cramer-Rao lower bound(CRLB)when setting proper *** data processing results further illustrate the excellent performance of the novel PLL.

关键词： Doppler measurement:Cramer-Rao lower bound carrier tracking:phase locked loop signal correlation

A digital pulsar backend based on FPGA

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Research in Astronomy and Astrophysics 2017年第1期17卷 97-102页

作者： Jin-Tao Luo Lan Chen Jin-Lin Han Ali Esamdin ya-jun wu Zhi-Xuan Li Long-Fei Hao Xiu-Zhong Zhang National Time Service CenterChinese Academy of SciencesXi'an 710600China Key Laboratory of Time and Frequency Primary Standards Chinese Academy of SciencesXi'an 710600China National Astronomical Observatories Chinese Academy of SciencesBeijing 100012China Xinjiang Astronomical Observatory Chinese Academy of SciencesUrumqi 830011China Shanghai Institute of Technology Shanghai 200235China Yunnan Observatories Chinese Academy of SciencesKunming 650011China Shanghai Astronomical Observatory Chinese Academy of SciencesShanghai 200030China

A digital pulsar backend based on a Field Programmable Gate Array （FPGA） is developed. It is designed for incoherent de-dispersion of pulsar observations and has a maximum bandwidth of 512MHz. The channel bandwidth is fixed to 1 MHz, and the highest time resolution is 10 p.s. Testing observations were carried out using the Urumqi 25-m telescope administered by Xinjiang Astronomical Observatory and the Kunming 40-m telescope administered by Yunnan Observatories, targeting PSR J0332＋5434 in the L band and PSR J0437-4715 in the S band, respectively. The successful observation of PSR J0437-4715 demonstrates its ability to observe millisecond pulsars.

关键词： instrumentation miscellaneous - methods data analysis - pulsars general

Robust Adaptive Leader-following Control of a Class of Multi-agent Systems

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Robust Adaptive Leader-following Control of a Class of Multi...

第32届中国控制与决策会议

作者： Hao Tang ya-jun wu Xiao-Zheng Jin School of Electrical Engineering and Automation HeFei University of Technology School of Computer Science and Technology Qilu University of Technology(Shandong Academy of Sciences)

In this paper,the robust consensus control problem is investigated for a class of nonlinear second-order multi-agent systems against system time-varying state/input-independent *** designing adaptive schemes and state-feedback control gains,a distributed controller is constructed to ensure the bounded consensus of agents in the presence of the uncertainties,and nonlinear ***,a multiple coupled nonlinear forced pendulum is used to validate the feasibility of the proposed method.

关键词： Second-order multi-agent systems leader-following consensus nonlinear dynamics robust adaptive technique

来源： cnki会议评论

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核磁共振技术在高度近视临床研究中的应用

国际眼科杂志 2023年第4期23卷 612-615页

作者：吴雅俊李文生中南大学爱尔眼科学院湖南省长沙市410000 爱尔眼科集团上海爱尔眼科医院上海市200235

近视是一种可改变视觉皮层活动,并影响相应神经功能的危害性眼科疾病。目前我国的近视率呈空前上升之势,尤其是高度近视(HM),遂实现近视的有效防控及治疗极为重要。然而近视的具体发病机制至今仍未阐明,难以从根源上实现该病的防控防治... 详细信息

近视是一种可改变视觉皮层活动,并影响相应神经功能的危害性眼科疾病。目前我国的近视率呈空前上升之势,尤其是高度近视(HM),遂实现近视的有效防控及治疗极为重要。然而近视的具体发病机制至今仍未阐明,难以从根源上实现该病的防控防治。近年来,不断有研究从遗传、环境、神经递质等角度出发探讨近视的相关致病因素,但鲜有研究从大脑结构及神经活动的角度探讨近视的神经影像机制。随着磁共振成像技术的发展,脑影像逐步出现在近视的相关机制研究中,本文主要对近视的相关脑影像研究作一综述,以期为开展近视的临床防控防治工作提供重要参考依据。

关键词：近视高度近视磁共振成像磁共振功能成像

Observation of topological charge transformations in acoustic vortex using passive periodic systems

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Science China(Physics,Mechanics & Astronomy) 2025年第1期Mechanics & Astronomy) .卷 140-147页

作者： Di-Chao Chen Xie Liu Changqing Xu Da-Jian wu Ying Cheng Xiao-jun Liu School of Physics and Technology Nanjing Normal University Key Laboratory of Modern Acoustics School of Physics Nanjing University

Vortex transmutation utilizes a periodic system, which not only enables the alteration of the topological charge(TC) of unstable input vortices but also facilitates their transformation into stable structures. This approach is crucial for investigating the characteristics of vortices in various wave systems. Here, we achieve acoustic vortex TC transmutation by employing a welldesigned dual-structured plate external system(DPES). The interactions between the acoustic vortex and the finite-order discrete rotational symmetry lead to the transformation of its topological charge when complete rotational symmetry is broken to Nthorder discrete symmetry. Our results experimentally demonstrate the acoustic vortex TC transmutation based on passive artificial structures, enabling numerous applications in particle manipulation and information multiplexing as well as advancing our understanding and control over free-space acoustic vortices.

关键词： acoustic vortex topological charge transformation artificial structure