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Miniaturized time-of-flight neutron spin flipper using a high-TC superconductor

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Nuclear Science and Techniques 2022年第11期33卷 113-119页

作者： Yu-Chen Dong tian-Hao Wang Wolfgang Kreuzpaintner Xiao-Tao Liu Ze-Hui Li Yu-Dong Kang Jun-Pei Zhang long tian Chu-Yi Huang Bo Bai Xin Tong Institute of High Energy Physics Chinese Academy of SciencesBeijing 100049China Spallation Neutron Source Science Center Dongguan 523803China School of Nuclear Science and Technology University of Chinese Academy of SciencesBeijing 100049China Guangzhou Institute of Technology Xidian UniversityGuangzhou 510555China

A miniaturized neutron spin flipper based on a high-TC superconductor film,developed at the China Spallation Neutron Source(CSNS),is presented.A neutron spin flipper is an essential component for performing polarized neutron experiments and,as such,constitutes a high priority for developing CSNS’s polarized neutron *** provide the beamlines with a universal neutron spin flipper operating over a wide wavelength band,the neutron spin flipper utilizes non-adiabatic spin flipping during transit through opposite magnetic fields that are mutually shielded by the superconductor Meissner effect.A compact vacuum heat shield and a low-power consumption sterling refrigerator maintained the superconducting condition while reducing the size and power input of the *** prototype device was tested at the CSNS BL-20,which demonstrated a flipping efficiency of 99%at 4 A°.

关键词： Neutron Superconductor Scattering Spinflipper

A low-noise, high-SNR balanced homodyne detector for the bright squeezed state measurement in 1–100 kHz range

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Chinese Physics B 2020年第3期29卷 215-220页

作者： Jin-Rong Wang Qing-Wei Wang long tian Jing Su Yao-Hui Zheng State Key Laboratory of Quantum Optics and Quantum Optics Devices Institute of Opto-ElectronicsShanxi UniversityTaiyuan 030006China Collaborative Innovation Center of Extreme Optics Shanxi UniversityTaiyuan 030006China

We report a low-noise, high-signal-to-noise-ratio(SNR) balanced homodyne detector based on the standard transimpedance amplifier circuit and the inductance and capacitance combination for the measurement of the bright squeezed state in the range from 1 kHz to 100 kHz. A capacitance is mounted at the input end of the AC branch to prevent the DC photocurrent from entering the AC branch and avoid AC branch saturation. By adding a switch at the DC branch,the DC branch can be flexibly turned on and off on different occasions. When the switch is on, the DC output provides a monitor signal for laser beam alignment. When the switch is off, the electronic noise of the AC branch is greatly reduced at audio-frequency band due to immunity to the impedance of the DC branch, hence the SNR of the AC branch is significantly improved. As a result, the electronic noise of the AC branch is close to -125 dBm, and the maximum SNR of the AC branch is 48 dB with the incident power of 8 mW in the range from 1 kHz to 100 kHz. The developed photodetector paves a path for measuring the bright squeezed state at audio-frequency band.

关键词： quantum optics photodetector low-noise audio band

Corrosion Resistance of Co-containing Maraging Stainless Steel

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Acta Metallurgica Sinica(English Letters) 2018年第8期31卷 785-797页

作者： Jia-long tian Wei Wang M.Babar Shahzad Wei Yan Yi-Yin Shan Zhou-Hua Jiang Ke Yang School of Materials Science and Engineering Northeastern University Institute of Metal Research Chinese Academy of Sciences School of Metallurgy Northeastern University

Corrosion resistance behavior of Co-containing maraging stainless steels was investigated. Neutral salt spray and polarization test showed that maraging stainless steel with high Co content showed poor corrosion behavior. Microstructure observation proved that segregation of Cr in the matrix deteriorated its corrosion resistance. The surface morphology of the aged maraging stainless steel with high Co content indicated that during passivation process, the newly formed passive film with sinusoidal distribution readily destroyed by the corrosive medium, hence, causing poor corrosion resistance. Moreover, through first-principles calculation it was proved that Co increased Fe–Fe ferromagnetic interaction which facilitated the formation Cr-rich clusters.

关键词： Maraging stainless steel Corrosion resistance Passive film Atom probe tomography First-principles calculation

Advances of machining techniques for gradient structures in multi-principal-element alloys

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Rare Metals 2022年第12期41卷 4015-4026页

作者： Bo Li Chun-Ming Niu tian-long Zhang Gong-Yu Chen Gang Zhang Dong Wang Xiao-Ye Zhou Jia-Ming Zhu School of Civil Engineering Shandong UniversityJinan 250061China School of Materials Science and Engineering University of Science and Technology BeijingBeijing 100083China Department of Materials Science and Engineering College of Science and EngineeringHong Kong Institute for Advanced StudyCity University of Hong KongHong Kong 999077China School of Physics and Optoelectronics Technology Baoji University of Arts and SciencesBaoji 721016China Center of Microstructure Science Frontier Institute of Science and TechnologyXi'an Jiaotong UniversityXi’an 710049China Guangdong Province Key Laboratory of Durability for Marine Civil Engineering School of Civil and Transportation EngineeringShenzhen UniversityShenzhen 518060China

Multi-principal-element alloys(MPEAs)are attracting increasing attentions because of their high strength and ductility,high fracture toughness,excellent corrosion resistance,outstanding thermal-softening resistance and high oxidation ***,gradient structures(GSs)have been shown to be effective in alleviating the strength-ductility trade-off although strength and ductility are mutually exclusive properties for metals,which provides an opportunity for developing highperformance ***,we summarized four processing methods for creating GSs in MPEAs,including rotationally accelerated shot peening(RASP),ultra-precision machining technology(UPMT),cyclic dynamic torsion(CDT),and ultrasonic surface rolling processing(USRP).Principles,advantages,disadvantages,and typical applications of these methods are discussed in this work.

关键词： Gradient structures(GSs) Multi-principalelement alloys(MPEAs) Strength-ductility trade-off Advanced processing technology

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黄金梨的气调贮藏保鲜试验

农业机械学报 2007年第10期38卷 77-79,27页

作者：田龙南阳师范学院生命科学与技术学院

为改进黄金梨的贮藏质量,延长货架期,从气调组分入手研究了气调贮藏对黄金梨的保鲜效果,以期得出比较理想的组分指标。采用CO2体积分数为0～0.5%,O2体积分数分别为2%～3%、5%～6%、8%～9%,在温度为(-1.5±0.5)℃、相对湿度为95%的条件下... 详细信息

为改进黄金梨的贮藏质量,延长货架期,从气调组分入手研究了气调贮藏对黄金梨的保鲜效果,以期得出比较理想的组分指标。采用CO2体积分数为0～0.5%,O2体积分数分别为2%～3%、5%～6%、8%～9%,在温度为(-1.5±0.5)℃、相对湿度为95%的条件下,进行了黄金梨气调贮藏研究。试验表明:在90d的贮藏期内,O2体积分数为5%～6%、CO2体积分数为0～0.5%时,能延缓黄金梨Vc含量、果肉硬度和乙烯释放量降低,减少乙醇和乙醛在果肉内的积累量。试验证明了气调储藏的优越性和可行性,补充了气体组分的数据参数。

关键词：黄金梨保鲜气调贮藏试验

Periodic synchronization in a system of coupled phase oscillators with attractive and repulsive interactions

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Frontiers of physics 2018年第3期13卷 163-169页

作者： Chong Xiao Jun-long tian Fang Lin Dong-Wei Ma Jing Zhang Hai-Tao Cui Yi Xiao School of Physics and Electrical Engineering Anyang Normal University Anyang 455000 China School of Physics Huazhong University of Science and Technology Wuhan 430074 China

In this study we investigate the collective behavior of the generalized Kuramoto model with an ex- ternal pinning force in which oscillators with positive and negative coupling strengths are conformists and contrarians, respectively. We focus on a situation in which the natural frequencies of the oscilla- tors follow a uniform probability density. By numerically simulating the model, it is shown that the model supports multistable synchronized states such as a traveling wave state, π state and periodic synchronous state： an oscillating π state. The oscillating π state may be characterized by the phase distribution oscillating in a confined region and the phase difference between conformists and contrar- ians oscillating around π periodically. In addition, we present the parameter space of the oscillating state and traveling wave state of the model.

关键词： generalized Kuramoto model pinning force conformists contrarians oscillating π state

An Efficient Ruthenium Catalyst Bearing Tetradentate Ligand forHydrogenations of Carbon Dioxide

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Chinese Journal of Chemistry 2018年第11期36卷 1000-1002页

作者： Feng-Hua Zhang Chong Liu Wei Li Gui-long tian Jian-Hua Xie Qi-Lin Zhou State Key Laboratory and Institute of Elemento-organic Chemistry Col-lege of Chemistry Nankai University Tianjin 300071 China Collaborative Innovation Center of Chemical Science and Engineering(tianjin) Tianjin 300071 China

A ruthenium complex with a tetradentate bipyridine ligand was proved to be a highly efficient catalyst for the conversions of CO2. Turnover numbers up to 300 000, 9800, and 2100 were achieved for the hydrogenations of CO2 to formamides, formamides to methanol and amines, and the direct hydrogenation of CO2 to methanol, respectively.

关键词： carbon dioxide methanol formamide ruthenium hydrogenation reduction

Demonstration of fully-connected quantum communication network exploiting entangled sideband modes

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Frontiers of physics 2023年第4期18卷 277-282页

作者： Fan Li Xiaoli Zhang Jianbo Li Jiawei Wang Shaoping Shi long tian Yajun Wang Lirong Chen Yaohui Zheng State Key Laboratory of Quantum Optics and Quantum Optics Devices Institute of Opto-ElectronicsShanxi UniversityTaiyuan 030006China Collaborative Innovation Center of Extreme Optics Shanxi UniversityTaiyuan 030006China

Quantum communication network scales point-to-point quantum communication protocols to more than two detached parties,which would permit a wide variety of quantum communication ***,we demonstrate a fully-connected quantum communication network,exploiting three pairs of Einstein–Podolsky–Rosen(EPR)entangled sideband modes,with high degree entanglement of 8.0 dB,7.6 dB,and 7.2 *** sideband modes from a squeezed field are spatially separated by demultiplexing operation,then recombining into new group according to network *** group of sideband modes are distributed to one of the parties via a single physical path,making sure each pair of parties build their own private communication links with high channel capacity better than any classical scheme.

关键词： quantum network quantum communication entangled sideband modes quantum dense coding

A new anchor-siphon drainage combined method used for slope stabilization

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Journal of Mountain Science 2023年第11期20卷 3295-3311页

作者： SUN Hong-yue WANG Xu YU Yang SHU Jun-wei WANG tian-long LUO Rui CHU Zhao-wei Ocean College Zhejiang UniversityZhejiang ProvinceZhoushan 316021China College of Civil Engineering and Architecture Zhejiang UniversityHangzhou 310058China

A new anchor-siphon drainage combined method used for slope stabilization is proposed in this *** includes an anchoring section and a siphon drainage *** novelty of the anchor-siphon drainage combined method is the realization of the drainage and anchoring in the one inclined *** engineering cost of drilling and the resulting disturbance to the slope is *** validate the feasibility of the proposed method,a numerical method that combines the pore water pressure distribution after siphon drainage and the anchoring force of the anchoring section is used to evaluate the safety of the slope with the anchor-siphon drainage *** proposed method was illustrated and validated with the Hongpu Village landslide,in Tonglu County,Zhejiang Province,in *** with the common anchor bar with the same length in the anchoring section,the factor of safety(FOS)for Hongpu Village slope with anchorsiphon drainage is increased by *** calculation method of the optimal length ratio between the drainage section and the anchoring section and its influencing factors were *** the different design parameters,there is always an optimal length ratio of the drainage *** with the siphon drainage and full-length anchor bar with the same borehole length,the anchor-siphon drainage combined method shows better landslide prevention ***,when the optimized parameters with a bond strength of 560kPa,a borehole inclination of 35°,and no reduction in length are used,the calculated safety factor is 1.316,which is significantly higher than the FOS of 1.131 for the slope with siphon drainage.

关键词： Landslide Safety factor Optimized design Siphon drainage Anchor New structure