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Polarized photoluminescence spectroscopy in WS_(2),WSe_(2) atomic layers and heterostructures by cylindrical vector beams
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作者 Lijun Wu Cuihuan Ge +5 位作者 Kai Braun Mai He Siman Liu Qingjun Tong Xiao Wang Anlian Pan 《Chinese Physics B》 SCIE EI CAS CSCD 2021年第8期42-48,共7页
Due to the large exciton binding energy,two-dimensional(2D)transition metal dichalcogenides(TMDCs)provide an ideal platform for studying excitonic states and related photonics and optoelectronics.Polarization states l... Due to the large exciton binding energy,two-dimensional(2D)transition metal dichalcogenides(TMDCs)provide an ideal platform for studying excitonic states and related photonics and optoelectronics.Polarization states lead to distinct light-matter interactions which are of great importance for device applications.In this work,we study polarized photoluminescence spectra from intralayer exciton and indirect exciton in WS_(2) and WSe_(2) atomic layers,and interlayer exciton in WS_(2)/WSe_(2) heterostructures by radially and azimuthally polarized cylindrical vector laser beams.We demonstrated the same in-plane and out-of-plane polarization behavior from the intralayer and indirect exciton.Moreover,with these two laser modes,we obtained interlayer exciton in WS_(2)/WSe_(2) heterostructures with stronger out-of-plane polarization,due to the formation of vertical electric dipole moment. 展开更多
关键词 two-dimensional transition metal dichalcogenides optical polarization interlayer exciton cylindrical vector beams
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Enzyme‐powered micromotors based on hierarchical porous MOFs
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作者 Lei Gan Paolo Falcaro Christian Doonan 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 2022年第3期584-585,共2页
Bioinspired micro‐/nano‐motors are artificial micro‐/nano‐machines that can convert various forms of energy to propel their movement[1].For example,the motion of some of these micromachines can be precisely contro... Bioinspired micro‐/nano‐motors are artificial micro‐/nano‐machines that can convert various forms of energy to propel their movement[1].For example,the motion of some of these micromachines can be precisely controlled by application of external physical stimuli including magnetic,electric and acoustic fields[2,3].Inspired by the study of microorganisms,researchers have been exploring also the use of available chemical energy from the local environment to trigger and sustain self‐propulsion[4].Within this research direction,Metal‐organic frameworks(MOFs)—a class of extended materials synthesized via a modular approach from inorganic(metal clusters or ions)and organic linkers[5]—offer excellent opportunities for the design and synthesis of self‐propelled micromotors.MOFs typically possess ultra‐high surface areas that allow facile access to densely populated catalytically active sites imbedded within their pore networks.Through careful design these catalytic sites can be exploited to convert chemical energy into kinetic energy resulting in self‐propulsion of the MOF crystal[6].In addition,rigidity,density,crystalline pore organization and pore size of MOFs can be optimized to carry out a swimming‐type motion[7]. 展开更多
关键词 CONVERT POROUS RIGIDITY
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Fluorescence Intensity Decay Shape Analysis Microscopy (FIDSAM) for Quantitative and Sensitive Live-Cell Imaging: A Novel Technique for Fluorescence Microscopy of Endogenously Expressed Fusion-Proteins 被引量:2
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作者 Frank Schleifenbaum Kirstin Elgass +4 位作者 Marcus Sackrow Katharina Caesar Kenneth Berendzen Alfred J. Meixner Klaus Hatter 《Molecular Plant》 SCIE CAS CSCD 2010年第3期555-562,共8页
Fluorescent studies of living plant cells such as confocal microscopy and fluorescence lifetime imaging often suffer from a strong autofluorescent background contribution that significantly reduces the dynamic image c... Fluorescent studies of living plant cells such as confocal microscopy and fluorescence lifetime imaging often suffer from a strong autofluorescent background contribution that significantly reduces the dynamic image contrast and the quantitative access to sub-cellular processes at high spatial resolution. Here, we present a novel technique--fluorescence intensity decay shape analysis microscopy (FIDSAM) to enhance the dynamic contrast of a fluorescence image of at least one order of magnitude. The method is based on the analysis of the shape of the fluorescence intensity decay (fluorescence lifetime curve) and benefits from the fact that the decay patterns of typical fluorescence label dyes strongly differ from emission decay curves of autofluorescent sample areas. Using FIDSAM, we investigated Arabidopsis thaliana hypocotyl cells in their tissue environment, which accumulate an eGFP fusion of the plasma membrane marker protein LTI6b (LTI6b-eGFP) to low level. Whereas in conventional confocal fluorescence images, the membranes of neighboring cells can hardly be optically resolved due to the strong autofluorescence of the cell wall, FIDSAM allows for imaging of single, isolated membranes at high spatial resolution. Thus, FIDSAM will enable the sub-cellular analysis of even low-expressed fluorophoretagged proteins in living plant cells. Furthermore, the combination of FIDSAM with fluorescence lifetime imaging provides the basis to study the local physico-chemical environment of fluorophore-tagged biomolecules in living plant cells. 展开更多
关键词 Cell structure cell walls membrane proteins high-resolution fluorescence microscopy.
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从电子鼻到生物电子鼻—人鼻和 MOSES 人工鼻的嗅觉感受 被引量:1
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作者 Wolfgang Gpel 《化学传感器》 CAS 1998年第4期2-20,共19页
模拟生物体嗅觉感受功能的电子鼻及生物电子鼻研究开发工作在近年来得到较大进展。德国T(?)bingen大学界面分析和传感器研究中心G(?)pel教授及意大利罗马大学电子工程系 D’Amico教授以及他们所领导的研究集体在这一领域中取得了不少开... 模拟生物体嗅觉感受功能的电子鼻及生物电子鼻研究开发工作在近年来得到较大进展。德国T(?)bingen大学界面分析和传感器研究中心G(?)pel教授及意大利罗马大学电子工程系 D’Amico教授以及他们所领导的研究集体在这一领域中取得了不少开创性的成果。他们在第七届国际化学传感器学术会议上的大会报告引起了与会学者的普遍兴趣与高度关注。应章宗穰教授的约请,G(?)pel教授为本刊提供了介绍T(?)bingen大学传感器研究中心研究成果的长篇专稿,内容极为丰富,并附有十余幅插图。现由章宗穰教授将其全文译出,在本期刊出。因篇幅所限,本文较为概括。读者如需对G(?)pel教授及其研究组的工作进展作进一步了解,可参阅文末所附参考文献,或依据文献5所提供的T(?)bingen大学传感器研究中心的网络地址直接查阅相关资料。在本文刊出之际,本刊编委会谨向G(?)pel教授表示深切谢意。 展开更多
关键词 电子鼻 传感器 MOSES 嗅觉
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IAG成员对扩展照相明胶知识领域的贡献
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作者 Adam Zaleski 周艳军 《明胶科学与技术》 CAS 2002年第2期90-96,共7页
1961年在苏黎世召开的国际照相科学会议上,由Borginon博士提议建立照相明胶国际工作组织,这一组织IAG于1962年正式成立(IAG这一缩写形式来源于德文Internationale Arbeitsgemainschaft fúr Forschung der Photo-Gelatine),尊敬的H.... 1961年在苏黎世召开的国际照相科学会议上,由Borginon博士提议建立照相明胶国际工作组织,这一组织IAG于1962年正式成立(IAG这一缩写形式来源于德文Internationale Arbeitsgemainschaft fúr Forschung der Photo-Gelatine),尊敬的H.Ammann-Brass教授任第一任主席。1983年,J.Pouradier教授继任主席直至1998年去世。在随后的两年里,M.De Clercq博士担任领导并使IAG的活动得以延续。 在1965~1994年间,IAG成员已经发表了由232位作者撰写的270篇论文。M.De Clercq和F.Moll在专论《照相研究领域30年的进展》中列举了这方面大量的工作。 在这篇论文中,我想展现IAG成员的主要研究成果,这些成果大大地扩展了我们在照相化学领域的知识。特别要注意的是下列这些方面的有关明胶的研究:卤化银在明胶溶液中的稀悬浮液浊度的测定以确定明胶的抑制或成熟性质;明胶的抑制能力;惰胶;明胶分子量的测定在照相乳剂制备中的作用,以及明胶众多的分析数据。对这些问题进行了讨论。毫无疑问,IAG的活动对照相化学的进步作出了重要的贡献。 展开更多
关键词 知识领域 论文 博士 疑问 活动 国际 教授 成员 继任 主席
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Two Types of Liquid Phase Separation Induced by Soft Centrifugation in Aqueous Ethyl Acetate Using Ethanol as Cosolvent
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作者 Helmut Cölfen Rose Rosenberg +3 位作者 Dirk Haffke Simon Stemplinger Thomas Zemb Dominik Horinek 《Research》 SCIE EI CSCD 2023年第3期451-460,共10页
Water/ethyl acetate/ethanol is widely used as a“green”extractant system.We show that 2 different types of phase separation can be induced upon centrifugation in this ternary system using ethanol as a cosolvent of wa... Water/ethyl acetate/ethanol is widely used as a“green”extractant system.We show that 2 different types of phase separation can be induced upon centrifugation in this ternary system using ethanol as a cosolvent of water and ethyl acetate:centrifuge-induced criticality and centrifuge-induced emulsification.The expected composition profiles of samples after centrifugation can be represented by bent lines in a ternary phase diagram when gravitational energy is added to the free energy of mixing.The experimental equilibrium composition profiles behave qualitatively as expected and can be predicted using a phenomenological theory of mixing.The concentration gradients are small except near the critical point,as expected for small molecules.Nevertheless,they are usable when accompanied by temperature cycles.These findings open new possibilities of centrifugal separation,even if control is delicate during temperature cycles.These schemes are accessible even at relatively low centrifugation speed for molecules that float and sediment with apparent molar masses several hundred times larger than the molecular mass. 展开更多
关键词 separation TERNARY APPARENT
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Special issue on a 90-year journey towards light from the intramolecular universe
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作者 Dai Zhang Hai Bi 《Light(Advanced Manufacturing)》 2024年第1期1-2,共2页
Over the past nearly 90 years,scientists have gradually revealed the mysteries of intramolecular motion and chemical bonds through continuous research and innovation.In 1928,Irish scientist E.Synge proposed a method t... Over the past nearly 90 years,scientists have gradually revealed the mysteries of intramolecular motion and chemical bonds through continuous research and innovation.In 1928,Irish scientist E.Synge proposed a method to overcome the limit of classical optical resolution,which laid the foundation for the subsequent development of scanning near-field optical microscopes.Near-field optical microscopy continues to push optical resolution to new records,well beyond the diffraction limit of traditional optical microscopy. 展开更多
关键词 INTRAMOLECULAR LIMIT BONDS
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Cesium lead halide perovskite triangular nanorods as high-gain medium and effective cavities for multiphoton- pumped lasing 被引量:12
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作者 Xiaoxia Wang Hong Zhou +8 位作者 Shuangping Yuan Weihao Zheng Ying Jiang Xiujuan Zhuang Hongjun Liu Qinglin Zhang Xiaoli Zhu Xiao Wang Anlian Pan 《Nano Research》 SCIE EI CAS CSCD 2017年第10期3385-3395,共11页
High-performance multiphoton-pumped lasers based on cesium lead halide perovskite nanostructures are promising for nonlinear optics and practical frequency upconversion devices in integrated photonics. However, the pe... High-performance multiphoton-pumped lasers based on cesium lead halide perovskite nanostructures are promising for nonlinear optics and practical frequency upconversion devices in integrated photonics. However, the performance of such lasers is highly dependent on the quality of the material and cavity, which makes their fabrication challenging. Herein, we demonstrate that cesium lead halide perovskite triangular nanorods fabricated via vapor methods can serve as gain media and effective cavities for multiphoton-pumped lasers. We observed blue-shifts of the lasing modes in the excitation fluence-dependent lasing spectra at increased excitation powers, which fits well with the dynamics of Burstein-Moss shifts caused by the band filling effect. Moreover, efficient multiphoton lasing in CsPbBr3 nanorods can be realized in a wide excitation wavelength range (700-1,400 nm). The dynamics of multiphoton lasing were investigated by time-resolved photoluminescence spectroscopy, which indicated that an electron-hole plasma is responsible for the multiphoton-pumped lasing. This work could lead to new opportunities and applications for cesium lead halide perovskite nanostructures in frequency upconversion lasing devices and optical interconnect systems. 展开更多
关键词 cesium lead halide perovskite NANORODS triangular cross-section multiphoton-pumped laser time-resolved photoluminescence
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Pentacene-based nanorods on Au(111) single crystals: Charge transfer, diffusion, and step-edge barriers
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作者 Sabine-Antonia Savu Sabine Abb +7 位作者 Simon Schundelmeier Jonathan D. Saathoff James M. Stevenson Christina Tonshoff Holger F. Bettinger Paulette Clancy M. Benedetta Casu Thomas Chasse 《Nano Research》 SCIE EI CAS CSCD 2013年第6期449-459,共11页
We investigate nanorod assemblies of two 64-substituted pentacenes, namely (2,3-X2-9,10-Y2)-substituted pentacenes with X -- Y = OCH3 (MOP) and with X = F, Y-- OCH3 (MOPF), grown on Au(111) single crystals. By... We investigate nanorod assemblies of two 64-substituted pentacenes, namely (2,3-X2-9,10-Y2)-substituted pentacenes with X -- Y = OCH3 (MOP) and with X = F, Y-- OCH3 (MOPF), grown on Au(111) single crystals. By using a multi-technique approach based on ultraviolet photoelectron spectroscopy X-ray photoelectron spectroscopy; and X-ray absorption, we find evidence for charge transfer screening at the interface with gold. Furthermore, the MOP and MOPF nanorods show a rough surface morphology, which was investigated with atomic force microscopy. We use molecular simulation techniques to investigate the energetic barriers to diffusion and to traverse step-edges to estimate their influence on the nanorod roughness. We find that barriers to surface diffusion on a terrace are anisotropic and that their direction favors the formation of nanorods in these materials. 展开更多
关键词 nanorod assembly substituted pentacene electronic structures/ processes/mechanisms organic electronics charge transfer diffusion and step-edge barrier
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Unraveling the mark of surface defects on a spinterface: The nitronyl nitroxide/TiO2(110) interface
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作者 Reza Kakavandi Arrigo Calzolari +4 位作者 Yulia B. Borozdina Prince Ravat Thomas Chasse Martin Baumgarten M. Benedetta Casu 《Nano Research》 SCIE EI CAS CSCD 2016年第11期3515-3527,共13页
Metal-free organic radicals are fascinating materials owing to their unique properties. Having a stable magnetic moment coupled to light elements makes these materials central to develop a large variety of application... Metal-free organic radicals are fascinating materials owing to their unique properties. Having a stable magnetic moment coupled to light elements makes these materials central to develop a large variety of applications. We investigated the magnetic spinterface coupling between the surface of a single rutile TiO2(110) crystal and a pyrene-based nitronyl nitroxide radical, using a combination of thickness-dependent X-ray photoelectron spectroscopy and ab initio calculations. The radicals were physisorbed, and their magnetic character was preserved on the (almost) ideal surface. The situation changed completely when the molecules interacted with a surface defect site upon adsorption. In this case, the reactivity of the defect site led to the quenching of the molecular magnetic moment. Our work elucidates the crucial role played by the surface defects and demonstrates that photoemission spectroscopy combined with density functional theory calculations can be used to shed light on the mechanisms governing complex interfaces, such as those between magnetic molecules and metal oxides. 展开更多
关键词 organic spinterface photoemission spectroscop density functional theory calculations
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Tuning red-green-white up-conversion color in nano NaYF_4:Er/Yb phosphor 被引量:3
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作者 A.Bednarkiewicz D.Wawrzynczyk +1 位作者 M.Nyk M.Samo 《Journal of Rare Earths》 SCIE EI CAS CSCD 2011年第12期1152-1156,共5页
The possibility of ttming between red, green and broadband white color of up-conversion was demonstrated in thermally 450 ℃ treated Yb/Er co-doped nano NaYF4 phosphor. The color variability was studied by means of po... The possibility of ttming between red, green and broadband white color of up-conversion was demonstrated in thermally 450 ℃ treated Yb/Er co-doped nano NaYF4 phosphor. The color variability was studied by means of power dependence of luminescence, which exhibited unusual behavior. Large hysteresis, as well as discrepancy from a power law indicated the important role the increased heating played during the up-conversion in nano-sized materials. 展开更多
关键词 LANTHANIDES UP-CONVERSION white up-conversion emission nanphosphors rare earths
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Novel highly active carbon supported ternary PdNiBi nanoparticles as I anode catalyst for the alkaline direct ethanol fuel cell 被引量:1
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作者 Bernd Cermenek Johanna Ranninger +4 位作者 Birgit Feketefoldi Ilse Letofsky-Papst Norbert Kienzl Brigitte Bitschnau Viktor Hacker 《Nano Research》 SCIE EI CAS CSCD 2019年第3期683-693,共11页
The study focuses on the in flue nee of Ni and Bi on alkali me etha nol oxidati on reacti on (EOR) activities, stabilities and structure characteristics of carb on supported Pd-based nano catalysts (Pd/C, Pd6oNi4o/C, ... The study focuses on the in flue nee of Ni and Bi on alkali me etha nol oxidati on reacti on (EOR) activities, stabilities and structure characteristics of carb on supported Pd-based nano catalysts (Pd/C, Pd6oNi4o/C, Pd6oBi4o/C, Pd6oNi2oBi2o/C) by cyclic voltammetry/chr ono amperometry using rotating disk electrode and various physico-chemical methods such as X-ray powder diffraction, X-ray photoelectron spectroscopy, transmission electron microscopy coupled with energy dispersive X-ray spectroscopy and inductively coupled plasma optical emission spectrometry. Nickel generates more adsorbed OH on the Pd catalyst surface than Bi and promotes the oxidation of adsorbed ethanol species. This results in a low onset potential toward ethanol oxidation with high current density. The presenee of Bi facilitates high toleranee toward various reaction in termediates resulting from the incomplete etha nol oxidation, but might also initiate the agglomerati on of Pd nano particles. The no vel Pd60Ni20Bi20/C nanocatalyst displays exceptional byproduct toleranee, but only satisfying catalytic activity toward ethanol oxidation in an alkaline medium. Therefore, the EOR performanee of the novel carbon supported ternary PdxNiyBiz anode catalyst with various atomic variations (Pd70Ni25Bi5/C, Pd70Ni20Bi10/C, Pd80Ni10Bi10/C and Pd40Ni20Bi40/C) using the common instant reduction synthesis method was further optimized for the alkaline direct ethanol fuel cell. The carbon supported Pd:Ni:Bi nano catalyst with atomic ratio of 70:20:10 displays outsta nding catalytic activity for the alkaline EOR compared to the other PdxNiyBiy/C nanocatalysts as well as to the benchmarks Pd/C, Pd60Ni40/C and Pd60Bi40/C. The synergy and the optimal content in consideration of the oxide species of Pd, Ni and Bi are crucial for the EOR kinetic enhancement in alkaline medium. 展开更多
关键词 ALKALINE direct ETHANOL fuel cell CATALYTIC activity ETHANOL OXIDATION reaction TERNARY PdNiBi nano CATALYSTS structure characteristics
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Tuning the fields focused by a high NA lens using spirally polarized beams(Invited Paper)
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作者 F.Wackenhut B.Zobiak +1 位作者 A.J.Meixner A.V.Failla 《Chinese Optics Letters》 SCIE EI CAS CSCD 2017年第3期51-54,共4页
We show the power of spirally polarized doughnut beams as a tool for tuning the field distribution in the focus of a high numerical aperture (NA) lens. Different and relevant states of polarization as well as field ... We show the power of spirally polarized doughnut beams as a tool for tuning the field distribution in the focus of a high numerical aperture (NA) lens. Different and relevant states of polarization as well as field distributions can be created by the simple turning of a λ/2 retardation wave plate placed in the excitation path of a micro- scope. The realization of such a versatile excitation source can provide an essential tool for nanotechnology investigations and biomedical experiments. 展开更多
关键词 Tuning the fields focused by a high NA lens using spirally polarized beams HIGH
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Picosecond electrical response in graphene/MoTe_(2) heterojunction with high responsivity in the near infrared region
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作者 Zhouxiaosong Zeng Kai Braun +12 位作者 Cuihuan Ge Martin Eberle Chenguang Zhu Xingxia Sun Xin Yang Jiali Yi Delang Liang Yufan Wang Lanyu Huang Ziyu Luo Dong Li Anlian Pan Xiao Wang 《Fundamental Research》 CAS 2022年第3期405-411,共7页
Understanding the fundamental charge carrier dynamics is of great significance for photodetectors with both high speed and high responsivity.Devices based on two-dimensional(2D)transition metal dichalcogenides can exh... Understanding the fundamental charge carrier dynamics is of great significance for photodetectors with both high speed and high responsivity.Devices based on two-dimensional(2D)transition metal dichalcogenides can exhibit picosecond photoresponse speed.However,2D materials naturally have low absorption,and when increasing thickness to gain higher responsivity,the response time usually slows to nanoseconds,limiting their photodetection performance.Here,by taking time-resolved photocurrent measurements,we demonstrated that graphene/MoTe_(2) van der Waals heterojunctions realize a fast 10 ps photoresponse time owing to the reduced average photocurrent drift time in the heterojunction,which is fundamentally distinct from traditional Dirac semimetal photodetectors such as graphene or Cd_(3)As_(2) and implies a photodetection bandwidth as wide as 100 GHz.Furthermore,we found that an additional charge carrier transport channel provided by graphene can ef-fectively decrease the photocurrent recombination loss to the entire device,preserving a high responsivity in the near-infrared region.Our study provides a deeper understanding of the ultrafast electrical response in van der Waals heterojunctions and offers a promising approach for the realization of photodetectors with both high responsivity and ultrafast electrical response. 展开更多
关键词 Two-dimension material Graphene/MoTe_(2)heterojunction Near infrared photodetector Scanning photocurrent microscopy Time-resolved photocurrent
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