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Azobenzene-based ultrathin peptoid nanoribbons for the potential on highly efficient artificial light-harvesting

Science China Chemistry 2024年第5期67卷 1680-1686页

作者： Zichao Sun Lingrong Zhu Jingze Liu Fan Liu Pengchao Wu Pengliang Sui Haibao Jin Shaoliang Lin Shanghai Key Laboratory of Advance Polymeric Materials Frontiers Science Center for Materiobiology and Dynamic ChemistrySchool of Materials Science and EngineeringEast China University of Science and TechnologyShanghai 200237China

The development of artificial light-harvesting systems based on long-range ordered ultrathin organic nanomaterials(i.e., below3 nm), which were assembled from stimuli-responsive sequence-controlled biomimetic polymers, remains challenging. Herein,we report the self-assembly of azobenzene-containing amphiphilic ternary alternating peptoids to construct photo-responsive ultrathin peptoids nanoribbons(UTPNRs) with a thickness of ~2.3 nm and the length in several micrometers. The pendants hydrophobic conjugate stacking mechanism explained the formation of one-dimensional ultrathin nanostructures, whose thickness was highly dependent on the length of side groups. The photo-isomerization of azobenzene moiety endowed the aggregates with a reversible morphology transformation from UTPNRs to spherical micelles(46.5 nm), upon the alternative irradiation with ultraviolet and visible light. Donor of 4-(2-hydroxyethylamino)-7-nitro-2,1,3-benzoxadiazole(NBD) and acceptor of rhodamine B(RB) were introduced onto the hydrophobic and hydrophilic regions, respectively, to generate photocontrollable artificial light-harvesting systems. Compared with the spheres-based systems, the obtained NBD-UTPNRs@RB composite proved a higher energy transfer efficiency(90.6%) and a lower requirement of RB acceptors in water. A proof-ofconcept use as fluorescent writable ink demonstrated the potential of UTPNRs on information encryption.

关键词： azobenzene-based peptoid ultrathin nanoribbon photo-responsive light-harvesting information encryption

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Regulation of pseudographitic carbon domain to boost sodium energy storage

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Nano Research 2024年第6期17卷 5188-5196页

作者： Zhidong Hou Mingwei Jiang Da Lei Xiang Zhang Yuyang Gao Jian-Gan Wang State Key Laboratory of Solidification Processing Center for Nano Energy MaterialsSchool of Materials Science and EngineeringNorthwestern Polytechnical University and Shaanxi Joint Lab of Graphene(NPU)Xi’an 710072China

Hard carbon anode has shown extraordinary potentials for sodium-ion batteries(SIBs)owing to the cost-effectiveness and advantaged ***,the widespread application of hard carbon is still hindered by the insufficient sodium storage capacity and depressed rate property,which are mainly induced by the undesirable pseudographitic ***,we develop a molten-salt-mediated strategy to regulate the pseudographitic structure of hard carbon with suitable interlayer spacing and enlarged pseudographitic domain,which is conducive to the intercalation capacity and diffusion kinetics of sodium ***,the optimized hard carbon anode delivers a high reversible capacity of 320 mAh·g^(−1),along with superior rate property(138 mAh·g−1 at 2 A·g^(−1))and stable cyclability over 1800 ***,the in situ Raman spectroscopic study and full-cell assembly further investigate the sodium storage mechanism and practical implement of obtained hard *** work pioneers a low-cost and effective route to regulate the pseudographitic structure of hard carbon materials for advanced SIBs.

关键词： pseudographitic structure molten salt hard carbon anode sodium-ion batteries

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Direction finding for two-dimensional incoherently distributed sources with Hadamard shift invariance in non-uniform orthogonal arrays

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Chinese Journal of Aeronautics 2018年第12期31卷 2260-2269页

作者： Zhengliang DAI Weijia CUI Daming WANG Bin BA Chao WANG Yankui ZHANG National Digital Switching System Engineering&technological Research center Zhengzhou 450001China

This paper proposes a novel algorithm for Two-Dimensional(2D) central Directionof-Arrival(DOA) estimation of incoherently distributed sources. In particular, an orthogonal array structure consisting of two Non-uniform Linear Arrays(NLAs) is considered. Based on first-order Taylor series approximation, the Generalized Array Manifold(GAM) model can first be established to separate the central DOAs from the original array manifold. Then, the Hadamard rotational invariance relationships inside the GAMs of two NLAs are identified. With the aid of such relationships, the central elevation and azimuth DOAs can be estimated through a search-free polynomial rooting method. Additionally, a simple parameter pairing of the estimated 2D angular parameters is also accomplished via the Hadamard rotational invariance relationship inside the GAM of the whole array. A secondary but important result is a derivation of closed-form expressions of the Cramer-Rao lower bound. The simulation results show that the proposed algorithm can achieve a remarkably higher precision at less complexity increment compared with the existing low-complexity methods, which benefits from the larger array aperture of the NLAs. Moreover, it requires no priori information about the angular distributed function.

关键词： Array signal processing Cramer-Rao lower bound Direction-of-Arrival(DOA) estimation Hadamard rotational invariance Incoherently distributed sources Non-uniform orthogonal array

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An Aware-Scheduling Security Architecture with Priority-Equal Multi-Controller for SDN

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China Communications 2017年第9期14卷 144-154页

作者： Chao Qi Jiangxing Wu Guozhen Cheng Jianjian Ai Shuo Zhao National Digital Switching System Engineering & technological R&D center

Current SDN controllers suffer from a series of potential attacks. For example, malicious flow rules may lead to system disorder by introducing unexpected flow entries. In this paper, we propose Mcad-SA, an aware decision-making security architecture with multiple controllers, which could coordinate heterogeneous controllers internally as a "big" controller. This architecture includes an additional plane, the scheduling plane, which consists of transponder, sensor, decider and scheduler. Meanwhile it achieves the functions of communicating, supervising and scheduling between data and control plane. In this framework, we adopt the vote results from the majority of controllers to determine valid flow rules distributed to switches. Besides, an aware dynamic scheduling(ADS) mechanism is devised in scheduler to intensify security of Mcad-SA further. Combined with perception, ADS takes advantage of heterogeneity and redundancy of controllers to enable the control plane operate in a dynamic, reliable and unsteady state, which results in significant difficulty of probing systems and executing attacks. Simulation results demonstrate the proposed methods indicate better security resilience over traditional architectures as they have lower failure probability when facing attacks.

关键词： multi-controller security architec-ture aware scheduling

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Computer Analysis of Electromagnetic Transients in Grounding Systems Considering Variation of Soil Parameters with Frequency

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Journal of Electromagnetic Analysis and Applications 2012年第12期4卷 475-480页

作者： Marco A.O.Schroeder Marcio M.Afonso Tarcisio A.S.Oliveira Sandro C.Assis Department of Electrical Engineering Federal University of Sao Joao del-ReiLaboratory of Applied ElectromagnetismSao Joao del-ReiBrazil Department of Electrical Engineering Federal Center of Technological Education of Minas GeraisBelo HorizonteBrazil Energetic Company of minas gerais Belo HorizonteBrazil

This paper presents a mathematical model to calculate transients in grounding systems. The derived equations arise from direct application of basic electromagnetic equations in frequency domain, whose solution is obtained by the application of the Moment Methods. A formulation based on experimental measurements is applied to quantify the soil parameters for each frequency. The unified approach is applied in the calculation of the grounding impedance of horizontal electrodes. Results show that the inclusion of frequency dependence of the soil parameters leads to a reduction of the values of grounding impedance, in comparison with results for soils with parameters independent of frequency.

关键词： Grounding Electrodes Grounding Impedance Transient Response Frequency Response Electromagnetic Modeling

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Adjustment of Forest Ecosystem Root Respiration as Temperature Warms

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Journal of Integrative Plant Biology 2008年第11期50卷 1467-1483页

作者： Andrew J.Burton Jerry M.Melillo Serita D.Frey Ecosystem Science center Michigan Technological University School of Forest Resources and Environmental Science Michigan Technological University The Ecosystems center Marine Biological Laboratory Department of Natural Resources University of New Hampshire

Adjustment of ecosystem root respiration to warmer climatic conditions can alter the autotrophic portion of soil respiration and influence the amount of carbon available for biomass production. We examined 44 published values of annual forest root respiration and found an increase in ecosystem root respiration with increasing mean annual temperature （MAT）, but the rate of this cross-ecosystem increase （Q10 = 1.6） is less than published values for short-term responses of root respiration to temperature within ecosystems （Q10 = 2-3）. When specific root respiration rates and root biomass values were examined, there was a clear trend for decreasing root metabolic capacity （respiration rate at a standard temperature） with increasing MAT. There also were tradeoffs between root metabolic capacity and root system biomass, such that there were no instances of high growing season respiration rates and high root biomass occurring together. We also examined specific root respiration rates at three soil warming experiments at Harvard Forest, USA, and found decreases in metabolic capacity for roots from the heated plots. This decline could be due to either physiological acclimation or to the effects of co-occurring drier soils on the measurement date. Regardless of the cause, these findings clearly suggest that modeling efforts that allow root respiration to increase exponentially with temperature, with Q10 values of 2 or more, may over-predict root contributions to ecosystem CO2 efflux for future climates and underestimate the amount of C available for other uses, including net primary productivity.

关键词： acclimation climatic warming root biomass root respiration soil warming.

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Initiation,organizational modes and environmental conditions of severe convective wind events during the warm season over North China

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Science China Earth Sciences 2024年第9期67卷 2876-2894页

作者： Yue HUANG Jianhua SUN Yuanchun ZHANG Ruoyun MA Xinlin YANG Fuyou TIAN Key Laboratory of Cloud-Precipitation Physics and Severe Storms(LACS) Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029China University of the Chinese Academy of Sciences Beijing 100049China Earth System Modeling and Prediction center China Meteorological AdministrationBeijing 100081China College of Aviation Meteorology Civil Aviation Flight University of ChinaGuanghan 618307China National Meteorological center China Meteorological AdministrationBeijing 100081China

Based on the significant weather report,CG lightning,composite radar reflectivity,and ERA5 reanalysis data,we first studied the spatiotemporal distribution characteristics of four types(only severe convective wind(SCW);SCW and hail;SCW and short-duration heavy rainfall(SDHR);and SCW,hail,and SDHR)of convective weather events related to SCW during the warm season(May to September)from 2011 to 2018 in North ***,severe convective cases producing SCW were selected to statistically analyze the initiation,decay,lifetime,and organizational characteristics of convective ***,using ERA5 reanalysis data and conventional surface observation data,preconvective soundings were constructed to explore the differences in environmental conditions for initiating convective systems between SCW and *** results indicate that mixed-type of SCW and SDHR events occur more frequently over plains,while other types of convective weather occur more frequently over *** frequency peak of SCW occurs in June,while mixed convective weather peaks in *** initiation time of convective systems is concentrated between 1000 and 1300 BST,with a peak at 1200 *** mountains,the daily peaks of ordinary and significant SCW generally occur at 1700-1800 BST and 1600-1700 BST,respectively,while over plains,the peak of ordinary SCW typically lags behind that of mountains by 1-2 ***,SCW systems are mainly initiated over mountains,with most lifetimes lasting 7–13 *** convective systems produce the most SCW events,followed by trailing-stratiform convective *** convective available potential energy(CAPE),downdraft convective available potential energy,and the temperature difference between 850 and 500 hPa can all distinguish between SCW systems and non-SCW systems occurring over *** to non-SCW convective systems,SCW convective systems over mountains are more likely to occur in environments with less precipitable water,while S

关键词： Severe convective wind Convective systems Initiation Organizational modes Environmental conditions

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Transformation optics applied to van der Waals interactions

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Science Bulletin 2016年第1期61卷 59-67页

作者： Rongkuo Zhao Yu Luo J.B.Pendry National Science foundation Nanoscale Science and Engineering center University of California Centre for Opto Electronics and Biophotonics (OPTIMUS) School of Electrical and Electronic Engineering Nanyang Technological University The Blackett Laboratory Department of Physics Imperial College London

The van der Waals force originates from the electromagnetic interaction between quantum fluctuationinduced charges. It is a ubiquitous but subtle force which plays an important role and has a wide range of applications in surface related phenomena like adhesion, friction,and colloidal stability. Calculating the van der Waals force between closely spaced metallic nanoparticles is very challenging due to the strong concentration of electromagnetic fields at the nanometric gap. Especially, at such a small length scale, the macroscopic description of the dielectric properties no longer suffices. The diffuse nonlocal nature of the induced surface electrons which are smeared out near the boundary has to be considered. Here,we review the recent progress on using three-dimensional transformation optics to study the van der Waals forces between closely spaced nanostructures. Through mapping a seemingly asymmetric system to a more symmetric counterpart, transformation optics enables us to look into the behavior of van der Waals forces at extreme length scales,where the effect of nonlocality is found to dramatically weaken the van der Waals interactions.

关键词： van der Waals forces Transformationoptics Nonlocality Plasmonics

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Construction Processes Paradigm and Reinforcement Alternatives for Tailings Dam Soil

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Journal of Environmental Protection 2023年第3期14卷 213-229页

作者： Magno André Oliveira Lucas Redoan Cecílio Campos Marcela Cristina Costa Branco Junia Lúcio de Castro Borges Gustavo Filemon Costa Lima Alan Rodrigues Teixeira Machado Augusto Cesar da Silva Bezerra School of Mines Geotechnics Nucleus Federal University of Ouro Preto Ouro Preto Brazil Institute of Geosciences Federal University of Pará Belém Brazil Transport Engineering Department Federal Center for Technological Education of Minas Gerais Belo Horizonte Brazil Department of Geography Federal University of Minas Gerais Belo Horizonte Brazil Department of Exact Sciences University of the State of Minas Gerais João Monlevade Brazil

In the last decade, Brazil was the scene of two of the world’s biggest disasters related to mining tailings dams. The collapse of the Mariana and Brumadinho dams was catastrophic event that brought to light major environmental and humanitarian crises. Facts like this incite debate on the safety of dam construction methods and highlight the need for a broad discussion of dam safety legislation in the country. From the above, this paper promotes a review of various forms of construction of tailings dams and their associated problems, as well as discusses the techniques for soil reinforcement and their construction methods. The work also brings an overview of the Brazilian dams from April to July 2019, tracing the context of the Brazilian tailings dams months after the tragedy of Brumadinho. The methodology includes a robust literature review and discourse analysis. In Brazil, the number of ruptured dams is alarming, especially in the state of minas gerais, in which more than 7 have broken in the last two decades. Among the damages, the deaths impact society abruptly and were cataloged 455 deaths, of which 216 correspond to the rupture of the dam of the Córrego do Feijão mine in Brumadinho. To evaluate and diagnose a dam, one should consider ordinance N ° 70,389, 2017 revoked by Resolution ANM n ° 95, of February 7, 2022. In this context, in March 2019, we experienced several disturbing situations regarding dam instability in the state of minas gerais, being categorized as risky structures. To exemplify, one can cite dams classified as level 2 risk that became level 3. Due to the above facts, several studies are being conducted to improve soil aspects. For example, we highlight the increase in soil resistance that can be done using commercial and alternative materials available in the environment.

关键词： Dams Reinforcement Rupture minas gerais

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Conditioning treatments mitigate the levels of fecal pollution indicators in soil during land-application of sewage sludge

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Science China technological Sciences 2024年第10期67卷 3091-3102页

作者： WANG YuHang LI Hua FANG WenHao WANG Ru WANG XinXin ZHENG GuanYu ZHOU LiXiang Department of Environmental Engineering College of Resources and Environmental SciencesNanjing Agricultural University College of Materials and Chemical Engineering Pingxiang University Jiangsu Collaborative Innovation center for Solid Organic Waste Resource Utilization

Sewage sludge is a major source of fecal pathogens in the environment, and its application to land can result in a significant release of these pathogens into the soil. While conditioning treatments are crucial for improving the dewatering process of sludge, their impact on the presence and behavior of fecal pathogens in soil remains unclear. This study aims to assess four extraction methods for recovering fecal pollution indicators from soil amended with unconditioned and conditioned sludge. The indicators include Escherichia coli(EC), human-specific HF183 Bacteroides(HF183), human adenovirus(HAdV), human BK polyomavirus(BKPyV), human JC polyomavirus(JCPyV), and cross-assembly phage(crAssphage). This study also examines how soil moisture content affects the decay of these fecal pollution indicators in soil amended with raw sludge and investigates the influence of conditioning treatments with cationic polyacrylamide(PAM), Fenton's reagents, Fe[Ⅲ]/CaO on their persistence in soil. The results indicated that the direct extraction method was the most effective and unbiased for recovering fecal pollution indicators from sludge-amended soil compared with the three elution-concentration methods. All fecal pollution indicators, except HAdV, remained stable under dry soil conditions, while high soil moisture content(48.39%-53.14%) slowed the decay rates of these indicators. During the application of sludge to soil, effective control of fecal pollution indicators was observed, with JCPyVand HAdV becoming undetectable within a short period. The log reduction values of HF183, BKPyV, and crAssphage ranged from 0.1 to 2.8 logs after 30 d of cultivation. The application of conditioned sludge, especially Fenton's reagent-conditioned sludge, resulted in a reduction in human fecal contamination in the receiving soil. Therefore, implementing appropriate conditioning methods, such as using Fenton's reagent, can effectively mitigate the health risks associated with fecal pathogens.

关键词： fecal pollution indicators sewage sludge conditioning treatment land application soil

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