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Shaping attosecond pulses by controlling the minima in high-order harmonic generation through alignment of CO2 molecules

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Physical Review A 2020年第1期101卷 013429-013429页

作者： Cheng Jin Su-Ju Wang Xi Zhao Song-Feng Zhao C. D. Lin Department of Applied Physics Nanjing University of Science and Technology Nanjing 210094 China State Key Laboratory of Transient Optics and Photonics Xi'an Institute of Optics and Precision Mechanics Chinese Academy of Sciences Xi'an 710119 China J. R. Macdonald Laboratory Department of Physics Kansas State University Manhattan Kansas 66506 USA Key Laboratory of Atomic and Molecular Physics and Functional Materials of Gansu Province College of Physics and Electronic Engineering Northwest Normal University Lanzhou 730070 China

We report a simple method for generating shaped attosecond pulses by using a CO2 molecule. Unlike most other molecules, owing to its unique energy and angle dependence and the presence of deep minima in the photoionization transition dipole moment, the shape of harmonic spectra, especially the position and depth of minima, can be readily controlled by tuning the degree of alignment. The sensitive alignment dependence of the minima is due to the coherent interference of a laser-induced dipole from each molecule when CO2 molecules are moderately aligned, but not when they are well aligned or when they are isotropically distributed. Such a sensitivity offers a simple way of controlling the spectral amplitude and phase of the generated harmonics and thus shaping the generated attosecond pulses, for example, producing structured attosecond pulses by splitting a single burst into two. We illustrate how such pulses are generated and how to characterize them. This method offers a simple way to shape attosecond pulses at the generation step. It can be easily implemented experimentally to generate attosecond pulses with strong phase variations for unique applications.

关键词： High-order harmonic generation Multiphoton or tunneling ionization & excitation Ultrashort pulses

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Nanoscale Deformation Processes Revealed in Nacre of Pinna nobilis Mollusk Shells

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Microscopy and Microanalysis 2019年第S2期25卷 1880-1881页

作者： Jiseok Gim Noah Schnitzer Yuchi Cui Laura M. Otter Stephan E. Wolf Dorrit E. Jacob Amit Misra Robert Hovden Department of Materials Science & Engineering University of Michigan Ann Arbor MI USA. Department of Earth and Planetary Sciences Macquarie University Sydney Australia. Department of Materials Science & Engineering Friedrich-Alexander-University Erlangen-Nürnberg Erlangen Germany. Applied Physics Program University of Michigan Ann Arbor MI USA.

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Polyfunctional perovskite oxides optimized for efficient CO2 splitting against oxidative impurity via chemical looping

Research Square

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Research Square 2020年

作者： Liao, Xiangbiao Long, Yanhui Chen, Yan Zangiabadi, Amirali Wang, Hua Liu, Qinggang Li, Kongzhai Chen, Xi Earth Engineering Center Center for Advanced Materials for Energy and Environment Department of Earth and Environmental Engineering Columbia University New YorkNY10027 United States State Key Laboratory of Complex Nonferrous Metal Resources Clean Utilization Engineering Faculty of Chemical Engineering Kunming University of Science and Technology Kunming650093 China International Center for Applied Mechanics State Key Laboratory for Strength and Vibration of Mechanical Structures School of Aerospace Xi’an Jiaotong University Xi’an710049 China Department of Applied Physics and Applied Mathematics Columbia University New YorkNY10027 United States Department of Chemistry Tsinghua University Beijing China Faculty of Metallurgical and Energy Engineering Kunming University of Science and Technology Kunming650093 China School of Chemical Engineering Northwest University Xi’an710069 China

Via redox chemistry, chemical looping reduction of CO2 to CO provides a promising strategy for mitigating carbon emissions. However, it’s still challenging to directly reduce CO2/O2 mixture gas due to lack of effective oxygen carriers towards reductive C–O bond scission in the presence of strongly oxidative gas. Here, we report an autocatalytic strategy of polyfunctional perovskite oxides to achieve enhanced C–O bond activation and superior performance of methane driven syngas generation. The self-generated Ni nanoparticles, through Ni cations migrating from the bulk lattice to the surface of LaFeO3 perovskite under fast methane reduction, are identified as catalytically active sites for enhancing C-H activation in the methane oxidation step. The reduced Ni-LaFeO3 oxygen carrier features multifunctional active sites with Ni species for accelerating C–O activation and oxygen vacancies for O2 adsorption in the step of CO2 splitting with the presence of abundant O2. At 800℃, the 5 at.% Ni-LaFeO3 perovskite stably exhibited high performances during 100 redox cycles: 98% CO selectivity in the methane oxidation step, and 98.5% CO2 conversion in the step of CO2 splitting even with the presence of 25 at.% O2. This efficient and durable perovskite underpins an economic utilization of impure CO2 from various carbon sources with no requirement for energy-costing purifications. © 2020, CC BY.

关键词： Carbon dioxide

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On the composite design of wood branches leading to improved bending strength

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IOP Conference Series: materials science and engineering 2020年第1期942卷

作者： M Hartwig E K Gamstedt Uppsala University Division of Applied Mechanics Department of Materials Science and Engineering Box 534 SE-751 21 Uppsala Sweden

Wooden branches are designed to carry large bending moments, and so are longer composite structures, e.g. rotor blades for wind turbines. Being a natural fibrous composite material, wood is made from relatively simple biopolymer building blocks. In this preliminary work, we describe the composition and structure of softwood branches, including 3D images from X-ray computed tomography. The main difference in branch structure compared with other wood tissues is the reaction wood formed on the compressive side in e.g. spruce and pine. A simple beam is used to show that maximum bending moment is multiplied several times solely from the reaction wood. This is noteworthy, since chemical composition of the reaction wood does not differ significantly from the rest of the wood. The tissue gradients in the branch resulting from variation in density, microfibrillar angle and cell geometry contribute to the strength improvements. In composite structures, sandwich design is used to improve the load carrying capacity. From a general perspective, also local features as found in wood, such as smooth gradients and controlled cellular structure, could be further explored to improve bending strength in engineered composite materials.

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High-Energy-Density Foldable Battery Enabled by Zigzag-Like Design

High-Energy-Density Foldable Battery Enabled by Zigzag-Like ...

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中国力学大会（CCTAM 2019）

作者： Xiangbiao Liao Changmin Shi Tianyang Wang Boyu Qie Youlong Chen Pengfei Yang Qian Cheng Haowei Zhai Meijie Chen Xue Wang Xi Chen Yuan Yang Yonghong Zhang Family Center for Advanced Materials for Energy and Environment Department of Earth and Environmental Engineering Columbia University Program of Materials Science and Engineering Department of Applied Physics and Applied Mathematics Columbia University School of Aerospace Xi’an Jiaotong University School of Energy Science and Engineering Harbin Institute of Technology School of Astronautics Harbin Institute of Technology

Flexible batteries, seamlessly compatible with flexible and wearable electronics, attract a great deal of research attention. Current designs of flexible batteries struggle to meet one of the most extreme yet common d... 详细信息

关键词： energy density flexible foldable lithium ion batteries nonflammable

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Correction to: Understanding the carbonation of concrete with supplementary cementitious materials: a critical review by RILEM TC 281-CCC

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materials and Structures 2020年第1期54卷 1-2页

作者： von Greve-Dierfeld, Stefanie Lothenbach, Barbara Vollpracht, Anya Wu, Bei Huet, Bruno Andrade, Carmen Medina, César Thiel, Charlotte Gruyaert, Elke Vanoutrive, Hanne Saéz del Bosque, Isabel F. Ignjatovic, Ivan Elsen, Jan Provis, John L. Scrivener, Karen Thienel, Karl-Christian Sideris, Kosmas Zajac, Maciej Alderete, Natalia Cizer, Özlem Van den Heede, Philip Hooton, Robert Douglas Kamali-Bernard, Siham Bernal, Susan A. Zhao, Zengfeng Shi, Zhenguo De Belie, Nele TFB Technology and Research for Concrete Structures Wildegg Switzerland Swiss Federal Laboratories for Materials Science and Technology (Empa) Laboratory for Concrete and Construction Chemistry Dübendorf Switzerland Faculty of Civil Engineering Institute of Building Materials Research RWTH Aachen University Aachen Germany Microlab Faculty of Civil Engineering and Geosciences Delft University of Technology Delft The Netherlands LafargeHolcim Innovation Center Saint-Quentin-Fallavier Cedex France International Centre for Numerical Methods in Engineering (CIMNE) Barcelona Spain Department of Construction Institute for Sustainable Regional Development (INTERRA) University of Extremadura Cáceres Spain Technical University of Munich Center for Building Materials Munich Germany Department of Civil Engineering Structural Mechanics and Building Materials KU Leuven Ghent Belgium Department of Materials and Structures Faculty of Civil Engineering Institute of Materials and structures University of Belgrade Belgrade Serbia Department of Earth and Environmental Sciences KU Leuven Louvain Belgium Department of Materials Science and Engineering University of Sheffield Sheffield UK Construction Materials Laboratory École polytechnique fédérale de Lausanne Lausanne Switzerland Department of Civil Engineering and Environmental Sciences University of the Bundeswehr Munich Neubiberg Germany Department of Civil Engineering Democritus University of Thrace Xanthi Greece Global R&D HeidelbergCement AG Leimen Germany Department of Structural Engineering and Building Materials Ghent University Ghent Belgium Departement of Civil Engineering KU Leuven Louvain Belgium Department of Civil and Mineral Engineering University of Toronto Toronto Canada National Institute of Applied Sciences of Rennes Rennes France School of Civil Engineering University of Leeds Leeds UK Building Materials Urban and Environment Research University of Liège Liège Belgium

Dr. Isabel Martins was missing from the RILEM membership list that was published in the original article. The original article has been corrected.

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Nanostructure formation during electrospark alloying

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AIP Conference Proceedings 2024年第1期3130卷

作者： Oksana P. Haponova Viacheslav B. Tarelnyk Bogdan Antoszewski Nataliia V. Tarelnyk Applied Material Science and Technology of Constructional Materials Department Sumy State University Rymskogo-Korsakova st. 2 40007 Sumy Ukraine Department of Experimental Mechanics Institute of Fundamental Technological Research Polish Academy of Sciences Pawińskiego St. 5B 02-106 Warsaw Poland Technical Service Department Sumy National Agrarian University H. Kondratiieva Str. 160 40021 Sumy Ukraine Laser Research Centre Faculty of Mechatronics and Mechanical Engineering Kielce University of Technology Al. Tysiąclecia P.P. 7 Kielce 25-314 Poland

There have been considered the coating structure modification after electrospark alloying (ESA) by the Mo-electrode using a paste with carbon nanotubes. It was showed that the regimes and composition of the paste influenced the microstructure, continuity, roughness, and hardness of the coatings. The microstructures after the ESA of the Armco iron were studied. The use of higher discharge energy in ESA leads to an increase in surface roughness, coating thickness, and coating continuity. The use of higher discharge energy during ESA results in an increase in surface roughness, coating thickness, and coating continuity. The microstructures reveal nanoscale phases from 40 to 60 nm, which are evenly distributed in the coatings. The addition of ARKEMA nanotubes increases the hardness to 608 HV. The results of local X-ray diffraction analysis showed that carbon is concentrated on the surface, while molybdenum is distributed homogeneously in the coating. The addition of nanotubes to the paste before ESA improves hardness and continuity. The effect of nanotubes on the structure and properties of coatings is positive.

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Isolated Electron Trap-Induced Charge Accumulation for Efficient Photocatalytic Hydrogen Production

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Angewandte Chemie 2023年第25期135卷

作者： Prof. Dr. Wenhuan Huang Chenyang Su Dr. Chen Zhu Dr. Tingting Bo Dr. Shouwei Zuo Prof. Wei Zhou Yuanfu Ren Prof. Yanan Zhang Prof. Jing Zhang Prof. Magnus Rueping Prof. Huabin Zhang Key Laboratory of Chemical Additives for China National Light Industry College of Chemistry and Chemical Engineering Shaanxi University of Science and Technology Xi'an 710021 P. R. China KAUST Catalysis Center (KCC) King Abdullah University of Science and Technology (KAUST) Thuwal 23955-6900 Saudi Arabia Contribution: Conceptualization (lead) Department of Applied Physics Tianjin Key Laboratory of Low Dimensional Materials Physics and Preparing Technology Faculty of Science Tianjin University Tianjin 300072 P. R. China Contribution: Conceptualization (supporting) Chemistry Program Physical Science and Engineering Division King Abdullah University of Science and Technology (KAUST) Thuwal 23955-6900 Saudi Arabia Beijing Synchrotron Radiation Facility Institute of High Energy Physics Chinese Academy of Sciences Beijing 100049 P. R. China Contribution: Conceptualization (equal)

The solar-driven evolution of hydrogen from water using particulate photocatalysts is considered one of the most economical and promising protocols for achieving a stable supply of renewable energy. However, the efficiency of photocatalytic water splitting is far from satisfactory due to the sluggish electron-hole pair separation kinetics. Herein, isolated Mo atoms in a high oxidation state have been incorporated into the lattice of Cd 0.5 Zn 0.5 S (CZS@Mo) nanorods, which exhibit photocatalytic hydrogen evolution rate of 11.32 mmol g −1 h −1 (226.4 μmol h −1 ; catalyst dosage 20 mg). Experimental and theoretical simulation results imply that the highly oxidized Mo species lead to mobile-charge imbalances in CZS and induce the directional photogenerated electrons transfer, resulting in effectively inhibited electron-hole recombination and greatly enhanced photocatalytic efficiency.

关键词： Electron Pump High-Oxidation State Photocatalysis Single-Atom Catalysts Water Splitting

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Overcoming small-bandgap charge recombination in visible and NIR-light-driven hydrogen evolution by engineering the polymer photocatalyst structure

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Nature communications 2024年第1期15卷 707页

作者： Mohamed Hammad Elsayed Mohamed Abdellah Ahmed Zaki Alhakemy Islam M A Mekhemer Ahmed Esmail A Aboubakr Bo-Han Chen Amr Sabbah Kun-Han Lin Wen-Sheng Chiu Sheng-Jie Lin Che-Yi Chu Chih-Hsuan Lu Shang-Da Yang Mohamed Gamal Mohamed Shiao-Wei Kuo Chen-Hsiung Hung Li-Chyong Chen Kuei-Hsien Chen Ho-Hsiu Chou Department of Chemistry Faculty of Science Al-Azhar University Nasr City 11884 Cairo Egypt. Institute of Atomic and Molecular Sciences Academia Sinica Taipei 10617 Taiwan. Center for Condensed Matter Sciences National Taiwan University Taipei 10617 Taiwan. Department of Chemical Engineering National Tsing Hua University Hsinchu 300044 Taiwan. Department of Chemistry United Arab Emirates University Al Ain P.O. Box 15551 United Arab Emirates. Department of Chemistry Qena Faculty of Science South Valley University 83523 Qena Egypt. Chemical Physics and NanoLund Lund University 22100 Lund Sweden. Chemistry Department Faculty of Science Al-Azhar University Assiut 71542 Egypt. Sustainable Chemical Science and Technology Taiwan International Graduate Program Taipei Taiwan. Department of Applied Chemistry National Yang Ming Chiao Tung University Hsinchu 30010 Taiwan. Institute of Chemistry Academia Sinica 128 Sec 2 Academia Rd. Nankang Taipei 11529 Taiwan. Institute of Photonics Technologies National Tsing Hua University Hsinchu 300044 Taiwan. Center of Atomic Initiative for New Materials National Taiwan University Taipei 10617 Taiwan. Department of Chemical Engineering National Chung Hsing University Taichung 40227 Taiwan. Department of Materials and Optoelectronic Science Center for Functional Polymers and Supramolecular Materials National Sun Yat-Sen University Kaohsiung 804 Kaohsiung Taiwan. Department of Physics National Taiwan University Taipei 10617 Taiwan. Department of Chemical Engineering National Tsing Hua University Hsinchu 300044 Taiwan. hhchou@mx.nthu.edu.tw.

Designing an organic polymer photocatalyst for efficient hydrogen evolution with visible and near-infrared (NIR) light activity is still a major challenge. Unlike the common behavior of gradually increasing the charge recombination while shrinking the bandgap, we present here a series of polymer nanoparticles (Pdots) based on ITIC and BTIC units with different π-linkers between the acceptor-donor-acceptor (A-D-A) repeated moieties of the polymer. These polymers act as an efficient single polymer photocatalyst for H2 evolution under both visible and NIR light, without combining or hybridizing with other materials. Importantly, the difluorothiophene (ThF) π-linker facilitates the charge transfer between acceptors of different repeated moieties (A-D-A-(π-Linker)-A-D-A), leading to the enhancement of charge separation between D and A. As a result, the PITIC-ThF Pdots exhibit superior hydrogen evolution rates of 279 µmol/h and 20.5 µmol/h with visible (>420 nm) and NIR (>780 nm) light irradiation, respectively. Furthermore, PITIC-ThF Pdots exhibit a promising apparent quantum yield (AQY) at 700 nm (4.76%).

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Immobilization of poly(hexamethylene biguanide) to cellulose acetate- and cellulose-based nanofiber membranes for antibacterial and cytotoxic studies

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Biochemical engineering Journal 2024年 205卷

作者： Dinh Thi My Huong Chi-Yun Wang Pin-Yi Chen Chien Wei Ooi Xue Er Crystal Thew Bing-Lan Liu Chen-Yaw Chiu Shen-Long Tsai Kuei-Hsiang Chen Yu-Kaung Chang Department Chemical Technology and Environment University of Technology and Education the University of Da Nang Da Nang City Viet Nam Department Chemical Engineering/ Graduate School of Biochemical Engineering Ming Chi University of Technology New Taipei City 243303 Taiwan Department Chemical Engineering National Taiwan University of Science and Technology Taipei City 10607 Taiwan International Ph.D. Program in Innovative Technology of Biomedical Engineering and Medical Devices Ming Chi University of Technology New Taipei City 243303 Taiwan Bone and Joint Research Centre Chang Gung Memorial Hospital Taoyuan City 333423 Taiwan Research Center for Intelligent Medical Devices Ming Chi University of Technology New Taipei City 243303 Taiwan Chemical Engineering Department School of Engineering Monash University Malaysia Jalan Lagoon Selatan Bandar Sunway Selangor 47500 Malaysia Advanced Engineering Platform School of Engineering Monash University Malaysia Jalan Lagoon Selatan 47500 Bandar Sunway Selangor Malaysia Department of Applied Chemistry Chaoyang University of Technology Taichung 413310 Taiwan Department of Chemical Engineering and Materials Science Yuan Ze University Zhongli Dist Taoyuan City 320315 Taiwan

To develop the environmental antibacterial membrane, the physical attachments of poly (hexamethylene biguanide) hydrochloride (PHMB) on the cellulose acetate (CA) and regenerated cellulose (RC) electrospun nanofiber membranes were employed. The immobilization of PHMB increased the antibacterial efficacy ( AE , %) of nanofiber membranes from 65.67% to approximately 86.13% for CA-PHMB and from 35.09% to approximately 100% for RC-PHMB. The results of the chemical and physical characteristics indicate that the degree of deacetylation of CA nanofiber, the surface charge of the nanofiber, and the density of PHMB immobilized onto the nanofiber primarily affect the antibacterial efficacy. The use of mathematical models, such as the Temkin equilibrium model for PHMB immobilization and the Monod-type model for the relationship between antibacterial activity and immobilization density of PHMB provides a deeper understanding of the interactions and kinetics involved. The rapid achievement of ∼100% AE after only 10 min of contact with Escherichia coli ( E. coli ) is a notable finding, indicating the quick and efficient antibacterial action of RC-PHMB nanofiber membranes. Furthermore, maintaining approximately 100% AE after 20 days of storage underscores the long-term stability of PHMB immobilized on RC nanofiber membranes. The findings suggest that RC-PHMB holds great promise as an antibacterial material for biomedical applications, food packaging industries, and filtration or treatment of water.

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