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Polarization-dependent photoinduced metal–insulator transitions in manganites

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Science Bulletin 2024年第2期69卷 183-189页

作者： lina Deng Weiye Zhang hanxuan lin Lifen Xiang Ying Xu Yadi Wang Qiang Li Yinyan Zhu Xiaodong Zhou Wenbin Wang Lifeng Yin Hangwen Guo Chuanshan Tian Jian Shen State Key Laboratory of Surface Physics Institute for Nanoelectronic Devices and Quantum Computingand Department of PhysicsFudan UniversityShanghai 200433China Shanghai Research Center for Quantum Sciences Shanghai 201315China Zhangjiang Fudan International Innovation Center Fudan UniversityShanghai 201210China Collaborative Innovation Center of Advanced Microstructures Nanjing 210093China Shanghai Branch CAS Center for Excellence and Synergetic Innovation Center in Quantum Information and Quantum PhysicsShanghai 201315China

In correlated oxides,collaborative manipulation on light intensity,wavelength,pulse duration and polarization has yielded many exotic discoveries,such as phase transitions and novel quantum *** view of potential optoelectronic applications,tailoring long-lived static properties by light-induced effects is highly *** far,the polarization state of light has rarely been reported as a control parameter for this ***,we report polarization-dependent metal-to-insulator transition(MIT)in phaseseparated manganite thin films,introducing a new degree of freedom to control static ***,we observed giant photoinduced resistance jumps with striking features:(1)a single resistance jump occurs upon a linearly polarized light incident with a chosen polarization angle,and a second resistance jump occurs when the polarization angle changes;(2)the amplitude of the second resistance jump depends sensitively on the actual change of the polarization *** transmittance measurements reveal that the origin of the above phenomena is closely related to the coexistence of anisotropic *** results represent a first step to utilize light polarization as an active knob to manipulate static phase transitions,pointing towards new pathways for nonvolatile optoelectronic devices and sensors.

关键词： Metal-insulator phase transitions Polarization of light Electronic phase separation Selective domain controllability

Spatial confinement tuning of quenched disorder effects and enhanced magnetoresistance in manganite nanowires

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Science China(Physics,Mechanics & Astronomy) 2020年第3期63卷 106-111页

作者： Yang Yu Qiang Li Qian Shi YinYan Zhu hanxuan lin Hao Liu HongYan Chen Tian Miao Yu Bai YanMei Wang WenTing Yang WenBin Wang HangWen Guo LiFeng Yin Jian Shen State Key Laboratory of Surface Physics and Department of Physics Fudan UniversityShanghai 200433China Institute for Nanoelectronic Devices and Quantum Computing Fudan UniversityShanghai 200433China Collaborative Innovation Center of Advanced Microstructures Nanjing 210093China

Complex oxides have rich functionalities and advantages for future *** many systems,quenched disorder often holds the key to determine their physical properties,and these properties can be further tuned by chemical ***,understanding the role of quenched disorder is complicated because chemical doping simultaneously alters other physical variables such as local lattice distortions and electronic and magnetic ***,we show that spatial confinement is an effective approach to tuning the level of quenched disorder in a complex-oxide system while leaving other physical variables largely *** the confinement of a manganite system down to quasi-one-dimensional nanowires,we observed that the nature of its metal-insulator phase transition exhibits a crossover from a discontinuous to a continuous characteristic,in close accordance with quenched disorder *** argue that the quenched disorder,finite size,and surface effects all contribute to our experimental ***,with reduced nanowire width,the magnetoresistance shows substantial enhancement at low *** findings offer new insight into experimentally tuning the quenched disorder effect to achieve novel functionalities at reduced dimensions.

关键词： quenched disorder manganite nanowires phase transition colossal magnetoresistance

Visualization of tunnel magnetoresistance effect in single manganite nanowires

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Chinese Physics B 2020年第1期29卷 103-106页

作者： Yang Yu Wenjie Hu Qiang Li Qian Shi Yinyan Zhu hanxuan lin Tian Miao Yu Bai Yanmei Wang Wenting Yang Wenbin Wang Hangwen Guo Lifeng Yin Jian Shen State Key Laboratory of Surface Physics and Department of Physics Fudan UniversityShanghai 200433China Institute for Nanoelectronic Devices and Quantum Computing Fudan UniversityShanghai 200433China Collaborative Innovation Center of Advanced Microstructures Nanjing 210093China

We reported a study of tunnel magnetoresistance(TMR)effect in single manganite nanowire via the combination of magnetotransport and magnetic force microscopy *** value up to 290%has been observed in single(La1-yPry)1-x CaxMnO3 nanowires with varying *** find that the TMR effect can be explained in the scenario of opening and blockade of conducting channels from inherent magnetic domain *** findings provide a new route to fabricate TMR junctions and point towards future improvements in complex oxide-based TMR spintronics.

关键词： manganite nanowires tunnel magnetoresistance magnetic force microscope

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坎格雷洛的合成工艺改进

中国医药工业杂志 2020年第8期51卷 987-991页

作者：林汉轩王素云王立峰华南理工大学广东广州510006 华诺通(北京)医药科技有限公司北京100070

本研究对坎格雷洛(1)的合成工艺进行了改进。鸟嘌呤核苷(2)经乙酰化反应、2步氯代反应得2,6-二氯-9-(2,3,5-三-O-乙酰基-β-D-呋喃核糖基)嘌呤(5),5经氨基取代、脱保护和硫代反应得N6-(2-甲硫基乙基)-2-(3,3,3-三氟丙硫基)腺嘌呤核苷(8... 详细信息

本研究对坎格雷洛(1)的合成工艺进行了改进。鸟嘌呤核苷(2)经乙酰化反应、2步氯代反应得2,6-二氯-9-(2,3,5-三-O-乙酰基-β-D-呋喃核糖基)嘌呤(5),5经氨基取代、脱保护和硫代反应得N6-(2-甲硫基乙基)-2-(3,3,3-三氟丙硫基)腺嘌呤核苷(8)。硫代反应中,采用自制的三氟丙硫醇代替过硫醚试剂,提高了反应活性,6步总收率由15%提高至33%。由8合成1时,使用“一锅法”3步连续反应,并且后处理时采用正丁醇萃取纯化代替离子交换分离纯化,操作简便,产物1纯度达到99.10%。

关键词：坎格雷洛抗凝血药合成工艺改进

Recommendation over time: a probabilistic model of time-aware recommender systems

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Science China(Information Sciences) 2019年第11期62卷 81-94页

作者： Zuoquan lin hanxuan CHEN Department of Information Science School of Mathematical Sciences Peking University

In time-aware recommender systems, we have to consider the dynamic aspect of recommendation that is fond of new coming data. Usually, the recent data is more closely related to current recommendation tasks and the early data are useful to indicate overall measurements of the preferences. We propose a probabilistic model that uses the early data to generate the prior distribution and the recent data to capture the change of the states of both users and items in collaborative filtering systems. Our model is dynamic in the sense that it updates every time receiving new data. The time cost of every updating has a constant limit, which is suitable to deal with large scale data for online recommendation. Experiments on real datasets show the improvement performance of our model over the existing time-aware recommender systems.

关键词： recommender system collaborative filtering hidden Markov model precision cold start

Synthesis and biological evaluation of a lipopeptide-based methamphetamine vaccine

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Chinese Chemical Letters 2021年第4期32卷 1575-1579页

作者： Fan Liao hanxuan Wang Yuankun Dao Kai Yuan Jiazhen Lu Jie Shi Ying Han Suwei Dong lin Lu Peking University Sixth Hospital Peking University Institute of Mental HealthNHC Key Laboratory of Mental Health(Peking University)National Clinical Research Center for Mental Disorders(Peking University Sixth Hospital)Beijing 100191China National Institute on Drug Dependence and Beijing Key Laboratory of Drug Dependence Peking UniversityBeijing 100191China State Key Laboratory of Natural and Biomimetic Drugs and Department of Chemical BiologySchool of Pharmaceutical SciencesPeking UniversityBeijing 100191China Peking-Tsinghua Center for Life Sciences and PKU-IDG/McGovem Institute for Brain Research Academy for Advanced Interdisciplinary Studies Peking UniversityBeijing 100871China School of Basic Medicine Tongji Medical CollegeHuazhong University of Science and TechnologyWuhan 430030China

We describe an application of carrier protein-free strategy in constructing a fully synthetic methamphetamine(METH)vaccine that contains three components:Toll-like receptor 2 ligand,Th2 epitope,and METH *** immunological evaluation in mice revealed high titers of METH-specific antibodies induced by the construct and the activation of humoral immunity that would be beneficial for neutralization and clearance of the METH *** ral experiments indicated that the synthetic vaccine attenuated the acquisition of METH-induced conditioned place preference and inhibited the initiation and expression of METH-induced locomotor *** results demonstrate that the lipopeptide-based vaccine has invo ked an immune response and showed the potential of preventing the rewarding and psychoactive effects of METH.

关键词： METH vaccine Carrier protein-free Fully synthesis Lipopeptide Behavioral model

Chemical Synthesis of Interferon Gamma

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Chemical Synthesis of Interferon Gamma

第十一届全国化学生物学学术会议

作者： Yuankun Dao lin Han hanxuan Wang Suwei Dong State Key Laboratory of Natural and Biomimetic Drugs and Department of Chemical BiologySchool of Pharmaceutical SciencesPeking University

Interferon gamma（IFN-γ） is an important N-glycosylated protein produced primarily by T-lymphocytes and natural killer cells.[1] As a cytokine that is crucial for innate and adaptive immunity against viral infection, IFN-γ also exhibits anti-proliferative, immunoregulatory and proinflammatory activities.[2] Herein, we described our studies toward the chemical synthesis of IFN-γ via an α-selective lysine ligation. The synthetic protein exhibits comparable anti-cancer activity to recombinant IFN-γ in an anti-proliferation assay.[3]

关键词： Interferon gamma α-selectivity lysine ligation

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钴铁镍三元水滑石催化PMS降解水中刚果红

环境工程学报 2017年第9期11卷 4903-4909页

作者：施周曾寒轩邓林湖南大学土木工程学院长沙410082 湖南大学建筑安全与节能教育部重点实验室长沙410082

采用化学共沉淀法制备由过渡金属钴、铁、镍组成的磁性三元水滑石Co Fe Ni-LDH,催化过硫酸氢钾(PMS)产生SO-4·自由基,降解水中偶氮染料刚果红(CR),系统地考察了初始pH、催化剂投加量、PMS投加量对降解CR的影响。实验结果表明:在pH=4.0~... 详细信息

采用化学共沉淀法制备由过渡金属钴、铁、镍组成的磁性三元水滑石Co Fe Ni-LDH,催化过硫酸氢钾(PMS)产生SO-4·自由基,降解水中偶氮染料刚果红(CR),系统地考察了初始pH、催化剂投加量、PMS投加量对降解CR的影响。实验结果表明:在pH=4.0~10.0范围内,Co Fe Ni-LDH/PMS催化体系对CR的降解速率均较高;随着Co Fe Ni-LDH和PMS投加量的增加,CR的降解速率也逐渐加快。3次循环再生实验后,Co Fe Ni-LDH对CR的降解率在20 min内依然保持在88%左右。实验结果表明,这种新型磁性三元水滑石不仅具有高效的催化效果而且易于从水中分离,在有机染料废水的处理方面,有着良好的前景。

关键词：水滑石磁性催化过硫酸氢钾刚果红

活性炭负载钴铁氧体催化PMS降解水中罗丹明B

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环境工程学报 2018年第5期12卷 1372-1381页

作者：邓林邹志言曾寒轩施周张文湖南大学土木工程学院建筑安全与节能教育部重点实验室长沙410082 天津大学化工学院天津市膜科学与海水淡化重点实验室天津300350

采用化学共沉淀法制备了磁性活性炭负载钴铁氧体(CoFe_2O_4@AC),用于催化过硫酸氢钾(PMS)产生SO_4^-·自由基降解水中罗丹明B(RhB)。采用SEM、HR-TEM、XRD、FTIR、XPS等测试手段对CoFe_2O_4@AC的表面物理化学特性进行了表征,考察了PMS... 详细信息

采用化学共沉淀法制备了磁性活性炭负载钴铁氧体(CoFe_2O_4@AC),用于催化过硫酸氢钾(PMS)产生SO_4^-·自由基降解水中罗丹明B(RhB)。采用SEM、HR-TEM、XRD、FTIR、XPS等测试手段对CoFe_2O_4@AC的表面物理化学特性进行了表征,考察了PMS投加量、RhB浓度、pH、温度对降解RhB的影响。实验结果表明:与AC/PMS、CoFe_2O_4/PMS相比,CoFe_2O_4@AC/PMS催化体系对RhB具有更高的降解效率,且适用于较宽的pH范围(pH=5.0~9.0);CoFe_2O_4@AC/PMS体系对RhB的降解随温度的升高而显著加快,其降解活化能为67.46kJ·mol^(-1)。降解机理研究结果表明,复合材料中的AC和Co(Ⅱ)协同参与了催化PMS产生·OH和SO_4^-·的过程。总之,磁性CoFe_2O_4@AC不仅具有高效的催化效果而且易于从水中分离,对有机染料废水的处理有着良好的前景。

关键词：活性炭铁氧体催化过硫酸氢钾罗丹明B