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EMC design for actuators in the FAST reflector

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Research in Astronomy and Astrophysics 2018年第4期18卷 123-128页

作者： Hai-Yan Zhang ming-chang wu You-Ling Yue Heng-Qian Gan Hao Hu Shi-Jie Huang National Astronomical Observatories Chinese Academy of Sciences Beijing 100101 China Key Laboratory of Radio Astronomy Chinese Academy of Sciences Nanjing 210034 China

An active reflector is one of the three main innovations incorporated in the Five-hundredmeter Aperture Spherical radio Telescope（FAST）.The deformation of such a huge spherically shaped reflector into different transient parabolic shapes is achieved by using 2225 hydraulic actuators which change the position of the 2225 nodes through the connected down tied *** each different tracking process of the telescope,more than 1/3 of these 2225 actuators must be in operation to tune the parabolic aperture accurately and meet the surface error *** means that some of these actuators are inevitably located within the main beam of the receiver,and Electromagnetic Interference（EMI）from the actuators must be mitigated to ensure the scientific output of the *** on the threshold level of interference detrimental to radio astronomy described in ITU-R Recommendation RA.769 and EMI measurements,the shielding efficiency（SE）requirement for each actuator is set to be 80 d B in the frequency range from 70 MHz to 3 ***,Electromagnetic Compatibility（EMC）was taken into account in the actuator design by measures such as power line filters,optical fibers,shielding enclosures and other structural *** 2015,all the actuators had been installed at the FAST *** now,no apparent EMI from the actuators has been detected by the receiver,which demonstrates the effectiveness of these EMC measures.

关键词： radio telescope — active reflector actuator — electromagnetic compatibility

First application of large reactivity measurement through rod drop based on three-dimensional space–time dynamics

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Nuclear Science and Techniques 2021年第2期32卷 11-23页

作者： Wen-Cong Wang Li-Yuan Huang Cai-Xue Liu Han Feng Jiang Niu Qi-Dong Dai Guo-En Fu Lin-Feng Yang ming-chang wu Nuclear Power Institute of China Chengdu 610041China

Abstract Reactivity measurement is an essential part of a zero-power physics test,which is critical to reactor design and *** rod drop experimental technique is used to measure the control rod worth in a zero-power physics *** conventional rod drop experimental technique is limited by the spatial effect and the difference between the calculated static reactivity and measured dynamic reactivity;thus,the method must be *** this study,a modified rod drop experimental technique that constrains the detector neutron flux shape function based on three-dimensional space–time dynamics to reduce the reactivity perturbation and a new method for calculating the detector neutron flux shape function are *** factors were determined using Monte Carlo N-particle transport code and transient analysis code for a pressurized water reactor at the Ulsan National Institute of Science and Technology and Xi’an Jiaotong University,and a large reactivity of over 2000 pcm was measured using the modified *** research evaluated the modified technique accuracy,studied the influence of the correction factors on the modification,and investigated the effect of constraining the shape function on the reactivity perturbation reduction caused by the difference between the calculated neutron flux and true value,using the new method to calculate the shape function of the detector neutron flux and avoiding the neutron detector response function(weighting factor)calculation.

关键词： Large reactivity measurement Rod drop technique Space-time dynamics Constrained shape function Monte Carlo N-particle

Robotic internal thoracic artery harvesting： the learning curve and graft patency

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Chinese Medical Journal 2013年第10期126卷 1982-1983页

作者： YANG ming GAO chang-qing wu Yang LIU Shuai Department of Cardiovascular Surgery People's Liberation ArmyGeneral Hospital Beijing 100853 China

Since the first report of totally endoscopic coronary artery bypass graft （CABG） using da Vinci SurgicalSystem （Intuitive Surgical, Sunnyvale, CA, USA） in 1999, the robotic technology has been applied to internal thoracic artery （ITA） harvesting for more than I0 years. We present the experience of robotic ITA skeletonized harvesting in 200 cases using the da Vinci S or da Vinci SI Surgical System. The learning curves of 1TA harvesting time and the results of ITA graft patency were evaluated.

关键词： robotics internal thoracic artery coronary artery bypass graft harvest

Plasmon-enhanced ultra-high photoresponse of single-wall carbon nanotube/copper/silicon near-infrared photodetectors

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Nano Research 2024年第7期17卷 5930-5936页

作者： Yi-ming Zhao Xian-Gang Hu Chao Chen Zuo-Hua Wang An-Ping wu Hong-Wang Zhang Peng-Xiang Hou chang Liu Hui-ming Cheng Shenyang National Laboratory for Materials Science Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China School of Materials Science and Engineering University of Science and Technology of ChinaShenyang 110016China National Engineering Research Center for Equipment and Technology of Cold Strip Rolling College of Mechanical EngineeringYanshan UniversityQinhuangdao 066004China Faculty of Materials Science and Engineering/Institute of Technology for Carbon Neutrality Shenzhen Institute of Advanced TechnologyChinese Academy of SciencesShenzhen 518055China

Single wall carbon nanotube(SWCNT)/Si heterojunction photodetectors have the advantages of high photoresponse ability and simple structure,however,their detection wavelength range are usually lower than 1100 nm,which limits their application in the infrared *** report a SWCNT/Cu/Si photodetector with both a high photoresponse and a detection range up to the infrared band by depositing a Cu nanoparticles(NPs)layer between a SWCNT film and a n-Si *** was found that the Cu NPs produce strong surface plasmon resonance(SPR)under laser irradiation,which breaks through the limitation of Si band gap and greatly improves the photoresponse of the SWCNT/Cu/Si photodetector in the near infrared *** responsivity(R)of the photodetector in the wavelength range of 1850–1200 nm reached 2.2–14.15 mA/W,which is the highest value in the reported plasmon enhanced n-Si based photodetectors,and about 20,000 times higher than that of a SWCNT/Si *** R value for 1550 nm wavelength used in optical communications reached~8.2 mA/W,which is 64%higher than the previously reported values of commonly used *** attribute the significant increase to the strong SPR and low Schottky barrier of Cu with n-Si,which facilitates the generation and transfer of the carriers.

关键词： single wall carbon nanotube photodetector silicon surface plasmon resonance copper

Brain Cognition Mechanism-Inspired Hierarchical Navigation Method for Mobile Robots

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Journal of Bionic Engineering 2024年第2期21卷 852-865页

作者： Qiang Zou Chengdong wu ming Cong Dong Liu Faculty of Robot Science and Engineering Northeastern UniversityShenyang110819China School of Mechanical Engineering Dalian University of TechnologyDalian116024China

Autonomous navigation is a fundamental problem in *** methods generally build point cloud map or dense feature map in perceptual space;due to lack of cognition and memory formation mechanism,traditional methods exist poor robustness and low cognitive *** a new navigation technology that draws inspiration from mammal’s navigation,bionic navigation method can map perceptual information into cognitive space,and have strong autonomy and environment *** improve the robot’s autonomous navigation ability,this paper proposes a cognitive map-based hierarchical navigation ***,the mammals’navigation-related grid cells and head direction cells are modeled to provide the robots with location *** then a global path planning strategy based on cognitive map is proposed,which can anticipate one preferred global path to the target with high efficiency and short ***,a hierarchical motion controlling method is proposed,with which the target navigation can be divided into several sub-target navigation,and the mobile robot can reach to these sub-targets with high confidence ***,some experiments are implemented,the results show that the proposed path planning method can avoid passing through obstacles and obtain one preferred global path to the target with high efficiency,and the time cost does not increase extremely with the increase of experience nodes *** motion controlling results show that the mobile robot can arrive at the target successfully only depending on its self-motion information,which is an effective attempt and reflects strong bionic properties.

关键词： Bionic navigation Spatial localization cells Global path planning Hierarchical motion controlling

Tighter sum uncertainty relations via(α,β,γ)weighted Wigner–Yanase–Dyson skew information

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Communications in Theoretical Physics 2024年第3期76卷 91-99页

作者： Cong Xu Zhaoqi wu Shao-ming Fei School of Mathematical Sciences Capital Normal UniversityBeijing 100048China Department of Mathematics Nanchang UniversityNanchang 330031China Max-Planck-Institute for Mathematics in the Sciences 04103 LeipzigGermany

We establish tighter uncertainty relations for arbitrary finite observables via(α,β,γ)weighted Wigner–Yanase–Dyson((α,β,γ)WWYD)skew *** results are also applicable to the(α,γ)weighted Wigner–Yanase–Dyson((α,γ)WWYD)skew information and the weighted Wigner–Yanase–Dyson(WWYD)skew *** also present tighter lower bounds for quantum channels and unitary channels via(α,β,γ)modified weighted Wigner–Yanase–Dyson((α,β,γ)MWWYD)skew *** examples are provided to illustrate the tightness of our uncertainty relations.

关键词： quantum channels (α,β,γ)WWYD skew information (α,β,γ)MWWYD skew information uncertainty relations

RFI measurements and mitigation for FAST

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Research in Astronomy and Astrophysics 2020年第5期20卷 171-174页

作者： Hai-Yan Zhang ming-chang wu You-Ling Yue Heng-Qian Gan Hao Hu Shi-Jie Huang Xin-Xin Zhang Jin-Hai Sun Bo Peng Ren-Dong Nan FAST Collaboration National Astronomical Observatories Chinese Academy of SciencesBeijing 100101China CAS Key Laboratory of FAST National Astronomical ObservatoriesChinese Academy of SciencesBeijing 100101China

Radio Frequency Interference(RFI)mitigation is essential for supporting the science output of Five-hundred-meter Aperture Spherical radio Telescope(FAST)due to its high *** order to protect FAST from RFI,an Electromagnetic Compatibility(EMC)study has been carried out and the operation of a Radio Quiet Zone(RQZ)is *** measurements of the telescope instruments and monitoring of the active radio services outside the site have revealed the radiation properties of the RFI *** on the measurement results and theoretical analysis,various EMC methods have been implemented for the telescope to decrease the ***,the main RFI sources in the FAST RQZ,such as mobile stations,broadcast stations and navigation instruments,have been identified,and the technical measures have been adopted to protect the quiet radio environment around the *** early science outputs of FAST have demonstrated the efficiency of RFI mitigation methods.

关键词： radio telescope:FAST radio frequency interference measurement mitigation

Supramolecular polymer-based gel fracturing fluid with a double network applied in ultra-deep hydraulic fracturing

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Petroleum Science 2024年第3期21卷 1875-1888页

作者： Yong-Ping Huang Yong Hu chang-Long Liu Yi-Ning wu Chen-Wei Zou Li-Yuan Zhang ming-Wei Zhao Cai-Li Dai School of Petroleum Engineering China University of Petroleum(East China)Qingdao266580ShandongPR China Shandong Key Laboratory of Oilfield Chemistry China University of Petroleum(East China)Qingdao 266580ShandongPR China SINOPEC Petroleum Exploration and Production Research Institute Beijing102206PR China CNOOC China Co Ltd Tianjin BranchTianjin300459PR China

A gel based on polyacrylamide,exhibiting delayed crosslinking characteristics,emerges as the preferred solution for mitigating degradation under conditions of high temperature and extended shear in ultralong *** viscosity/viscoelasticity of the fracturing fluid was required to maintain excellent proppant suspension properties before *** into account both the cost and the potential damage to reservoirs,polymers with lower concentrations and molecular weights are generally *** this work,the supramolecular action was integrated into the polymer,resulting in significant increases in the viscosity and viscoelasticity of the synthesized supramolecular polymer *** double network gel,which is formed by the combination of the supramolecular polymer system and a small quantity of Zr-crosslinker,effectively resists temperature while minimizing permeability damage to the *** results indicate that the supramolecular polymer system with a molecular weight of(268—380)×10^(4)g/mol can achieve the same viscosity and viscoelasticity at 0.4 wt%due to the supramolecular interaction between polymers,compared to the 0.6 wt%traditional polymer(hydrolyzed polyacrylamide,molecular weight of 1078×10^(4)g/mol).The supramolecular polymer system possessed excellent proppant suspension properties with a 0.55 cm/min sedimentation rate at 0.4 wt%,whereas the0.6 wt%traditional polymer had a rate of 0.57 cm/*** comparison to the traditional gel with a Zrcrosslinker concentration of 0.6 wt%and an elastic modulus of 7.77 Pa,the double network gel with a higher elastic modulus(9.00 Pa)could be formed only at 0.1 wt%Zr-crosslinker,which greatly reduced the amount of residue of the fluid after *** viscosity of the double network gel was66 m Pa s after 2 h shearing,whereas the traditional gel only reached 27 m Pa s.

关键词： Ultra-deep reservoir Gel fracturing fluid Double network Supramolecular polymer system Proppant suspension property

Comparison of engineering failures and seismic responses of 500 kV transformer-bushing systems in the 2022 Luding earthquake

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Earthquake Engineering and Engineering Vibration 2024年第4期23卷 1029-1041页

作者： Zhu Wang wu ming’er Xie Qiang Department of Structural Engineering Tongji UniversityShanghai 200092China Key Laboratory of Performance Evolution and Control for Engineering Structures(Tongji University) Shanghai 200092China

Cemented and mechanically clamped types of end fittings(fitting-C and fitting-M)are commonly used in transformer *** the Luding Ms 6.8 earthquake that occurred in China on September 5,2022,all transformer bushings with the two types of end fittings in a 500 kV substation were ***-earthquake field investigations were conducted,and the failures of the two types of bushings were *** elementary simulation models of the transformer-bushing systems were developed to simulate the engineering failures,and further compute their seismic responses for *** results indicate that the hitch lugs of the connection flange are structurally harmful to seismic ***-M can decrease the bending stiffness of the bushing due to the flexible sealing rubber *** it provides a more flexible connection that dissipates energy,the peak accelerations and relative displacements at the top of the bushing are significantly lower than those of the bushing with *** with fitting-C,fitting-M transfers the high-stress areas from the connection flange to the root of the porcelain,so the latter becomes the most vulnerable ***-M increases the failure risk of the low-strength porcelain,indicating the unsuitability of applying it in high-intensity fortification regions.

关键词： transformer bushing end fitting Luding earthquake,engineering failure seismic responses