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Intercalation and hybrid heterostructure integration of two-dimensional atomic crystals with functional organic semiconductor molecules

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Nano Research 2020年第11期13卷 2917-2924页

作者： Wen He Han Zang Songhua Cai Zhangyan Mu Cheng Liu mengning Ding Peng wang Xinran wang Key Laboratory of Mesoscopic Chemistry School of Chemistry and Chemical EngineeringNanjing UniversityNanjing210093China National Laboratory of Solid State Microstructures Nanjing UniversityNanjing210093China School of Electronic Science and Engineering and Collaborative Innovation Center of Advanced Microstructures Nanjing UniversityNanjing210093China Jiangsu Key Laboratory of Artificial Functional Materials College of Engineering and Applied Sciences and Collaborative Innovation Center of Advanced MicrostructuresNanjing UniversityNanjing210093China Department of Applied Physics The Hong Kong Polytechnic UniversityHung Hom999077KowloonHong KongChina Research Center for Environmental Nanotechnology(ReCENT) Nanjing UniversityNanjing210023China

Van der Waals(vdW)integration affords semiconductor heterostructures without constrains of lattice matching and opens up a new realm of functional devices by design.A particularly interesting approach is the electrochemical intercalation of two-dimensional(2D)atomic crystal and formation of superlattices,which can provide scalable production of novel vdW heterostructures.However,this approach has been limited to the use of organic cations with non-functional aliphatic chains,therefore failed to take the advantage of the vast potentials in molecular functionalities(electronic,photonic,magnetic,etc.).Here we report the integration of 2D crystal(MoS_(2),WS_(2),highly oriented pyrolytic graphite(HOPG),WSe_(2) as model systems)with electrochemically inert organic molecules that possess semiconducting characteristics(including perylene-3,4,9,10-tetracarboxylic dianhydride(PTCDA),pentacene and fullerene),through on-chip electrochemical intercalation.An unprecedented long-range spatial feature of intercalation has been achieved,which allowed facile assembly of a vertical MoS_(2)-PTCDA-Si junction.The intercalated heterostructure shows significant modulation of the lateral transport,and leads to a molecular tunneling characteristic at the vertical direction.The general intercalation of charge neutral and functional molecules defines a versatile platform of inorganic/organic hybrid vdW heterostructures with significantly extended molecular functional building blocks,holding great promise in future design of nano/quantum devices.

关键词： transition metal dichalcogenide electrochemical intercalation perylene-3,4,9,10-tetracarboxylic dianhydride(PTCDA) organic semiconductor inorganic/organic heterostructure

An Artificial Light-Harvesting System with Tunable Fluorescence Color in Aqueous Sodium Dodecyl Sulfonate Micellar Systems for Photochemical Catalysis

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Chinese Journal of Chemistry 2021年第10期39卷 2725-2730页

作者： Xinglong Li Ying wang Ao Song Minghui Zhang mengning Chen Man Jiang Shengsheng Yu Rongzhou wang Lingbao Xing School of Chemistry and Chemical Engineering Shandong University of TechnologyZiboShandong255000 China Resources and Environmental Engineering Shandong University of TechnologyZiboShandong 255000China

Main observation and conclusion In the present work,an artificial light-harvesting system with fluorescence resonance energy transfer(FRET)is successfully fabricated in aqueous sodium dodecyl sulfonate(SDS)micellar systems.Since the tight and orderly arrangement of dodecyl in the SDS micelles is hydrophobic,tetra-(4-pyridylphenyl)ethylene(4PyTPE)can be easily encapsulated into the hydrophobic layer of SDS micelles through noncovalent interaction,which exhibits aggregation-induced emission(AIE)phenomenon and can be used as energy donor.By using amphoteric sulforhodamine 101(SR101)fluorescent dye attached to the negatively charged surface of SDS micelles through electrostatic interaction as energy acceptor,the light-harvesting FRET process can be efficiently simulated.Through the steady-state emission spectra analysis in the micelle-mediated energy transfer from 4PyTPE to SR101,the fluorescence emission can be tuned and white light emission with CIE coordinates of(0.31,0.29)can be successfully achieved by tuning the donor/acceptor ratio.More importantly,to better mimic natural photosynthesis,the SDS micelles with 4PyTPE and SR101 FRET system showed enhanced catalytic activity in photochemical catalysis for dehalogenation ofα-bromoacetophenone in aqueous solution and the photocatalytic reaction could be extended to gram levels.

关键词： Micelles Self-assembly Light-harvesting Energy transfer Photochemical catalysis

Fatigue properties of titanium alloy custom short stems fabricated by electron beam melting

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Journal of Materials Science & Technology 2020年第17期52卷 180-188页

作者： Liao wang Shujun Li mengning Yan Yubo Cheng Wentao Hou Yiping wang Songtao Ai Rui Yang Kerong Dai Shanghai Key Laboratory of Orthopaedic Implants Department of Orthopaedic SurgeryShanghai Ninth People’s HospitalShanghai Jiao Tong University School of MedicineShanghai Jiao Tong UniversityShanghai 200030China Titanium Alloy Laboratory Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China Image Medraw Technology(Shanghai)Company Limited Shanghai 201100China

The fatigue properties of titanium alloy short-stems with four different lengths,manufactured by electron beam melting(EBM)technology,were investigated by in vitro test and finite element(FE)analysis.FE simulation results indicate that the maximum tensile stress concentrates at the lateral side of the stem body.The magnitude of the concentrated tensile stress increases and the corresponding area of the axial section decreases with increasing of stem length.Results from fatigue tests demonstrate that fatigue cracks mainly initiate from the rough surface of the stem where the maximum tensile stress concentrates.The fatigue strength decreases with the increase of stem length,which is attributed to the higher stress concentration on the longer stem surface.In addition,it is found that post EBM treatment via hot isostatic processing(HIP)is able to enhance the fatigue properties of the stems,since the pores generated during EBM are mostly closed during HIP.Our work also demonstrates that the stress concentration on the stem surface can be effectively mitigated and the corresponding fatigue properties of the EBM-fabricated titanium alloy short stem can be considerably improved by optimizing the design in the stem length.

关键词： Custom short stem Titanium alloy Electron beam melting Fatigue property

基于预测误差与位平面编码的密文域可逆信息隐藏算法

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网络与信息安全学报 2023年第6期9卷 34-45页

作者：王海勇吉梦凝南京邮电大学计算机学院江苏南京210023

随着云计算技术的发展,越来越多的用户使用云备份的方式存储一些重要文件,与此同时,人们对于隐私保护的要求日益增长。密文域可逆信息隐藏是一种可以在密文图像中嵌入秘密信息,保证无错提取秘密信息以及无损恢复原始图像的技术,该技术... 详细信息

随着云计算技术的发展,越来越多的用户使用云备份的方式存储一些重要文件,与此同时,人们对于隐私保护的要求日益增长。密文域可逆信息隐藏是一种可以在密文图像中嵌入秘密信息,保证无错提取秘密信息以及无损恢复原始图像的技术,该技术既保护了载体图像的安全性,又有效地在网络中传递隐私信息,能够应用于云环境实现对用户的隐私保护,受到研究者的广泛关注。针对现有密文域可逆信息隐藏算法嵌入率较低的问题,提出了基于预测误差与位平面编码的密文域可逆信息隐藏算法,该算法重点研究如何在保证安全性和可逆性的同时,实现高嵌入容量。所提算法对图像进行预处理,根据位平面分布的不同分别使用不同的方式编码,在图像中预留出大量空间,通过重排列将预留的空间放在低位平面中;使用密钥生成随机矩阵,对图像进行加密,以保证图像的安全性;将秘密信息嵌入预留的空间中。在接收端,合法接收者能够根据密钥可分离来实现秘密信息的无错提取以及原始图像的无损恢复。与现有算法相比,所提算法具有更高的嵌入率,在BOWS-2、BOSSBase和UCID这3个数据集上平均嵌入率分别达到了3.769 bit/pixel、3.874bit/pixel和3.148bit/pixel,分别比同类算法中性能最好的算法提升了12.5%、6.9%和8.6%。实验结果表明,所提算法能够充分利用图像的冗余性,有效提升嵌入率。

关键词：可逆信息隐藏密文域游程编码分离信息安全

Quantitative Surface Plasmon Interferometry via Upconversion Photoluminescence Mapping

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Research 2019年第1期2019卷 551-562页

作者： Anxiang Yin Hao Jing Zhan Wu Qiyuan He Yiliu wang Zhaoyang Lin Yuan Liu mengning Ding Xu Xu Zhe Fei Jianhui Jiang Yu Huang Xiangfeng Duan Department of Chemistry and Biochemistry University of CaliforniaLos AngelesCalifornia 90095USA School of Chemistry and Chemical Engineering Beijing Institute of TechnologyBeijing 100008China Department of Materials Science and Engineering University of CaliforniaLos AngelesCalifornia 90095USA State Key Laboratory for Chemo/Biosensing and Chemometrics College of Chemistry and Chemical EngineeringHunan UniversityChangsha 410082China Department of Physics&Astronomy Iowa State UniversityAmesIowa 50011USA California NanoSystems Institute University of CaliforniaLos AngelesCalifornia 90095USA

Direct far-field visualization and characterization of surface plasmon polaritons(SPPs)are of great importance for fundamental studies and technological applications.To probe the evanescently confined plasmon fields,one usually requires advanced near-field techniques,which is typically not applicable for real-time,high-throughput detecting or mapping of SPPs in complicated environments.Here,we report the utilization of rare-earth-doped nanoparticles to quantitatively upconvert invisible,evanescently confined SPPs into visible photoluminescence emissions for direct far-field visualization of SPPs in a complicated environment.The observed interference fringes between the SPPs and the coherent incident light at the metal surface provide a quantitative measurement of the SPP wavelength and the SPP propagating length and the local dielectric environments.It thus creates a new signaling pathway to sensitively transduce the local dielectric environment change into interference periodicity variation,enabling a new design of directly measurable,spectrometer-free optical rulers for rapid,ultrasensitive label-free detection of various biomolecules,including streptavidin and prostate-specific antigen,down to the femtomolar level.

关键词： visible dielectric measurable

Mobility in China, 2020: a tale of four phases

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National Science Review 2021年第11期8卷 110-120页

作者： Suoyi Tan Shengjie Lai Fan Fang Ziqiang Cao Bin Sai Bing Song Bitao Dai Shuhui Guo Chuchu Liu Mengsi Cai Tong wang Mengning Wang Jiaxu Li Saran Chen Shuo Qin Jessica R.Floyd Zhidong Cao Jing Tan Xin Sun Tao Zhou Wei Zhang Andrew J.Tatem Petter Holme Xiaohong Chen Xin Lu School of Business Central South University Institute of Big Data and Internet Innovations Hunan University of Technology and Business College of Systems Engineering National University of Defense Technology WorldPop School of Geography and Environmental ScienceUniversity of Southampton School of Mathematics and Big Data Foshan University State Key Laboratory on Blind Signal Processing State Key Laboratory of Management and Control for Complex Systems Institute of AutomationChinese Academy of Sciences Chinese Evidence-Based Medicine Center National Clinical Research Center for Geriatrics West China Hospital Sichuan University Big Data Research Center University of Electronic Science and Technology of China West China Biomedical Big Data Center West China Hospital Sichuan University Tokyo Tech World Hub Research Initiative Institute of Innovative Research Tokyo Institute of Technology

2020 was an unprecedented year,with rapid and drastic changes in human mobility due to the COVID-19 pandemic.To understand the variation in commuting patterns among the Chinese population across stable and unstable periods,we used nationwide mobility data from 318 million mobile phone users in China to examine the extreme fluctuations of population movements in 2020,ranging from the Lunar New Year travel season(chunyun), to the exceptional calm of COVID-19 lockdown,and then to the recovery period.We observed that cross-city movements,which increased substantially in chunyun and then dropped sharply during the lockdown,are primarily dependent on travel distance and the socio-economic development of cities.Following the Lunar New Year holiday,national mobility remained low until mid-February,and COVID-19 interventions delayed more than 72.89 million people returning to large cities.Mobility network analysis revealed clusters of highly connected cities,conforming to the social-economic division of urban agglomerations in China.While the mass migration back to large cities was delayed,smaller cities connected more densely to form new clusters.During the recovery period after travel restrictions were lifted,the netflows of over 55% city pairs reversed in direction compared to before the lockdown.These findings offer the most comprehensive picture of Chinese mobility at fine resolution across various scenarios in China and are of critical importance for decision making regarding future public-health-emergency response,transportation planning and regional economic development,among others.

关键词： human mobility travel restrictions COVID-19 mobile phone data behavioral response

A field-effect approach to directly profiling the localized states in monolayer MoS2

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Science Bulletin 2019年第15期64卷 1049-1055页

作者： Hao Wu Yuan Liu Zeyu Deng Hung-Chieh Cheng Dehui Li Jian Guo Qiyuan He Sen Yang mengning Ding Yun-Chiao Huang Chen wang Yu Huang Xiangfeng Duan Department of Materials Science and Engineering University of CaliforniaLos AngelesCA90095USA Department of Chemistry and Biochemistry University of CaliforniaLos AngelesCA90095USA California NanoSystems Institute University of CaliforniaLos AngelesCA90095USA

A fundamental understanding of the charge transport mechanism in two-dimensional semiconductors(e.g., MoS2) is crucial for fully exploring their potential in electronic and optoelectronic devices. By using monolayer graphene as the barrier-free contact to MoS2, we show that the field-modulated conductivity can be used to probe the electronic structure of the localized states. A series of regularly distributed plateaus were observed in the gate-dependent transfer curves. Calculations based on the variable-range hopping theory indicate that such plateaus can be attributed to the discrete localized states near mobility edge. This method provides an effective approach to directly profiling the localized states in conduction channel with an ultrahigh resolution up to 1 meV.

关键词： Two-dimensional layered materials Field-effect transistor Localized states Electronic transport Conductivity plateau

SnO_(2)/γ-Al_(2)O_(3)粒子电极制备及其电催化还原CO_(2)产甲酸性能研究

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太原理工大学学报 2024年第3期55卷 455-464页

作者：白金印卓孟宁侯静王立章中国矿业大学环境与测绘学院江苏徐州221116 北京城建设计发展集团股份有限公司南京分公司南京210022

【目的】电催化还原CO_(2)(CO_(2)RR)是降低大气中CO_(2)浓度的绿色可行方案,制备高催化性能和稳定性的催化剂尤为重要。【方法】以γ-Al_(2)O_(3)粒子为载体,采用浸渍-焙烧法制备了SnO_(2)/γ-Al_(2)O_(3)粒子电极用于电催化还原CO_(2... 详细信息

【目的】电催化还原CO_(2)(CO_(2)RR)是降低大气中CO_(2)浓度的绿色可行方案,制备高催化性能和稳定性的催化剂尤为重要。【方法】以γ-Al_(2)O_(3)粒子为载体,采用浸渍-焙烧法制备了SnO_(2)/γ-Al_(2)O_(3)粒子电极用于电催化还原CO_(2)产甲酸来测试其性能,并结合物化分析、电化学测试及长周期实验等手段对粒子电极的微观结构、物相组成、电催化活性、产甲酸性能和稳定性进行了探讨。【结果】物化分析结果表明,负载SnO_(2)前后的形貌由孔洞和裂痕状为主转变为裂层状,比表面积自310.18m^(2)/g增加到352.70m^(2)/g,粒子电极中Sn含量占比48.32%,SnO_(2)成功分散负载到γ-Al_(2)O_(3)表面。据电化学测试所得,SnO_(2)/γ-Al_(2)O_(3)粒子电极的伏安电量(扫速50mV/s)、交换电流密度和析氢电阻分别为40mC、20.02μA/cm^(2)和96.86Ω,与γ-Al_(2)O_(3)相比分别提高了37.93%、75.46%和6.80%,大幅提升CO_(2)RR活性的同时有效抑制了析氢副反应。SnO_(2)/γ-Al_(2)O_(3)粒子电极表现出良好的CO_(2)RR特性,反应时间2h的产甲酸速率为70.35μmol·h-1·cm-2,电流密度为4.94mA/cm^(2),法拉第效率和能量效率分别为79.05%、24.51%;经过12h连续电解,产甲酸法拉第效率仍高于67.81%,说明制备的SnO_(2)/γ-Al_(2)O_(3)粒子电极具有较强稳定性。

关键词： CO_(2)电催化还原 SnO_(2)/γ-Al_(2)O_(3)粒子电极产甲酸性能电极稳定性

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与天体有关的综合问题

物理教学探讨 2005年第22期23卷 16-18页

作者：王孟宁诸暨市中学浙江省诸暨市311811

随着航天技术的发展,勇气号火星探测器在火星表面顺利降落,人类对地球以外的天体越来越关心.与天体有关的物理问题受到越来越多的人的关注,谈论航天问题的人也越来越多.物理高考和物理习题中与天体有关的问题也越来越多,本文选择几例与... 详细信息

随着航天技术的发展,勇气号火星探测器在火星表面顺利降落,人类对地球以外的天体越来越关心.与天体有关的物理问题受到越来越多的人的关注,谈论航天问题的人也越来越多.物理高考和物理习题中与天体有关的问题也越来越多,本文选择几例与天体有关的综合问题,探讨此类问题如何求解.

关键词：综合问题地球表面重力加速度综合能力测试万有引力定律抛出点火星表面主序星中子星