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High-speed silicon photonic electro-optic Kerr modulation

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Photonics Research 2024年第1期12卷 51-60页

作者： JONATHAN PELTIER WEIWEI ZHANG LEOPOLD VIROT CHRISTIAN LAFFORGUE LUCAS DENIEL DELPHINE MARRIS-MORINI GUY AUBIN FARAH AMAR DENH TRAN XINGZHAO YAN CALLUM G.LITTLEJOHNS CARLOS ALONSO-RAMOS KE LI DAVID J.THOMSON GRAHAM REED LAURENT VIVIEN University Paris-Saclay CNRSCentre for Nanoscience and Nanotechnology(C2N)Palaiseau 91120France University Grenoble Alpes CEALETIGrenoble 38000France Optoelectronics Research centre Zepler Institute for Photonics and NanoelectronicsFaculty of Engineering and Physical SciencesUniversity of SouthamptonSouthampton SO171BJUK

Silicon-based electro-optic modulators contribute to easing the integration of high-speed and low-power consumption circuits for classical optical communications and data *** the plasma dispersion modulation,an alternative solution in silicon is to exploit the DC Kerr effect,which generates an equivalent linear electro-optical effect enabled by applying a large DC electric *** some theoretical and experimental studies have shown its existence in silicon,limited contributions relative to plasma dispersion have been achieved in high-speed modulation so *** paper presents high-speed optical modulation based on the DC Kerr effect in silicon PIN *** contributions of both plasma dispersion and Kerr effects have been analyzed in different waveguide configurations,and we demonstrated that the Kerr induced modulation is dominant when a high external DC electric field is applied in PIN ***-speed optical modulation response is analyzed,and eye diagrams up to 80 Gbit/s in NRZ format are obtained under a *** of 30 *** work paves the way to exploit the Kerr effect to generate high-speed Pockels-like optical modulation.

关键词： waveguide dispersion effect

Knotting ligands to control metal coordination geometry

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Science China Chemistry 2024年

作者： Fabien B.L.Cougnon Department of Chemistry and nanoscience centre University of Jyv?skyl?

Zinc is a metal of particular importance for life [1]. It is the most abundant transition metal in biological systems after iron and contributes both structural and catalytic roles to many cellular processes. The properties of ZnII, unlike those of any other first-row transition metal ions, explain its biological relevance. Due to its filled d-shell orbitals, ZnIIis redox-stable, has a ligand-field energy stabilization of zero and, consequently, no typical coordination number and geometry. Zinc metalloproteins exploit these features to carry a broad range of chemical reactions in mild *** metalloenzymes, unsaturated ZnIIcentres often act as redox-stable Lewis acids. The protein backbone provides a highly preorganized environment around the metal centre and accompanies the changes in coordination geometry occurring as substrate transformation proceeds, thereby modulating the metal reactivity.

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Visible light-driven photo remediation of hazardous cationic dye via Ce-doped WO_(3) nanostructures

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Journal of Rare Earths 2024年第5期42卷 869-878,I0003页

作者： Azra Haroon Kaseed Anwar Arham S.Ahmed Department of Physics Aligarh Muslim University202002AligarhIndia Interdisciplinary nanotechnology centre Aligarh Muslim University202002AligarhIndia

Ce-doped WO_(3) nanoparticles were successfully synthesized by the sol-gel method and characterized through advanced characterization *** high resolution transmission electron microscopy(HRTEM)and scanning electron microscopy(SEM)results show a reduction in the agglomeration of nanoparticles upon *** energy dispersive X-ray(EDX)analysis validates the existence of the Ce element in all the doped samples.X-ray photoelectron spectroscopy(XPS)and Raman spectra justify the presence of structural defects(oxygen vacancies)and successful formation of the monoclinic WO_(3) phase,*** Kubelka-Munk function indicates a decrease in band gap with doping,while photoluminescence(PL)spectra show intense visible and UV emissions,Significantly,all doped samples exhibit higher photocatalytic performance than pure WO_(3) nanoparticles,with the 6 wt%Ce-doped sample displaying the highest degradation *** with Ce can help to increase the surface area of WO_(3),thereby improving its photoactivity,Moreover,a correlation between PL and photocatalysis is established in the light of oxygen vacancies suggesting a direct dependence of high photocatalytic activity on strong PL signals of WO_(3) *** experiments further reveal that the degradation process is primarily driven by active species,providing insight into a plausible photocatalytic mechanism.

关键词： WO_(3) Rare-earth element Environmental crisis Oxygen vacancies Luminescence Photocatalysis

Defect mediated losses and degradation of perovskite solar cells:Origin impacts and reliable characterization techniques

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Journal of Energy Chemistry 2024年第7期94卷 217-253页

作者： Himangshu Baishy Ramkrishna Das Adhikari Mayur Jagdishbhai Patel Deepak Yadav Tapashi Sarmah Mizanur Alam Manab Kalita Parameswar Krishnan lyer centre for nanotechnology Indian Institute of Technology GuwahatiGuwahati 781039AssamIndia Department of Chemistry Indian Institute ofTechnology GuwahatGuwahati739AssamIndi

The rapid advancement of halide-based hybrid perovskite materials has garnered significant research attention,particularly in the domain of photovoltaic *** to their exceptional optoelec-tronic properties,they demonstrated power conversion efficiency(PcE)of over 25%in single junction solar *** the notable progress in PCE over the past decade,the inherent high defect density pre-senting in perovskite materials gives rise to several loss mechanisms and associated ion migration in per-ovskite solar cells(PsCs)during operational *** factors collectively contribute to a significant stability challenge in PsCs,placing their longevity far behind for *** numerous reports have explored defects,ion migration,and their impacts on device performance,a com-prehensive correlation between the types of defects and the degradation kinetics of perovskite materials and PsCs has been *** this context,this review aims to provide a comprehensive overview of the origins of defects and ion migration,emphasizing their correlation with the degradation kinetics of per-ovskite materials and PsCs,leveraging reliable characterization ***,these charac-terization techniques are intended to comprehend loss mechanisms by different passivation approaches to enhance the durability and PCE of PSCs.

关键词： Perovskite solar cells Defects lon migration Degradation Stability

Interwoven grain boundary makes homoporous and crystalline polymer membrane with high mechanical stability

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Science China Chemistry 2024年

作者： Lianshan Li Zhiyong Tang CAS Key Laboratory of Nanosystem and Hierarchical Fabrication CAS Center for Excellence in Nanoscience National Centre for Nanoscience and Technology University of Chinese Academy of Sciences

Membrane separation is widely used in industry to recover and capture gases or to purify liquids. Compared with conventional separation methods, such as cryogenic and adsorptive or absorptive separation, membrane separation is an energy-efficient and environment-friendly technique that occupies less space and can be operated in a continuous mode [1].

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Heterostructure Cu_(3)P-Ni_(2)P/CP catalyst assembled membrane electrode for high-efficiency electrocatalytic nitrate to ammonia

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Nano Research 2024年第6期17卷 4872-4881页

作者： Meng Jin Jiafang Liu Xian Zhang Shengbo Zhang Wenyi Li Dianding Sun Yunxia Zhang Guozhong Wang Haimin Zhang Laboratory of Materials Physics Centre for Environmental and Energy NanomaterialsAnhui Key Laboratory of Nanomaterials and NanotechnologyCAS Center for Excellence in NanoscienceInstitute of Solid State PhysicsHefei Institutes of Physical ScienceChinese Academy of SciencesHefei 230031China University of Science and Technology of China Hefei 230026China Anhui Contango New Energy Technology Co. Ltd.Hefei 230031China

Electrochemical nitrate reduction reaction(NO_(3)RR)is a promising means for generating the energy carrier ***,we report the synthesis of heterostructure copper-nickel phosphide electrocatalysts via a simple vapor-phase hydrothermal *** resultant catalysts were evaluated for electrocatalytic nitrate reduction to ammonia(NH_(3))in three-type electrochemical *** detail,the regulation mechanism of the heterogeneous Cu_(3)P-Ni_(2)P/CP-x for NO_(3)RR performance was systematically studied through the H-type cell,rotating disk electrode setup,and membrane-electrode-assemblies(MEA)*** a result,the Cu_(3)P-Ni_(2)P/CP-0.5 displays the practicability in an MEA system with an anion exchange membrane,affording the largest ammonia yield rate(RNH_(3))of 1.9 mmol·h^(−1)·cm^(−2),exceeding most of the electrocatalytic nitrate reduction electrocatalysts reported to *** theoretical calculations and in-situ spectroscopy characterizations uncover that the formed heterointerface in Cu_(3)P-Ni_(2)P/CP is beneficial for promoting nitrate adsorption,activation,and conversion to ammonia through the successive hydrodeoxygenation pathway.

关键词： electrocatalytic nitrate reduction to ammonia three-type reactors membrane-electrode-assemblies system operando ATR-IRRAS successive hydrodeoxygenation pathway

Tensile deformation of fine-grained Mg at 4K,78K and 298K

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Journal of Magnesium and Alloys 2024年第6期12卷 2534-2556页

作者： M.Walag A.Kula P.Noga T.Tokarski G.Cios M.Niewczas AGH University of Krakow Faculty of Non-Ferrous MetalsKrakowPoland AGH University of Krakow Academic Centre for Materials and NanotechnologyKrakowPoland Materials Science and Engineering McMaster UniversityHamiltonCanada

The impact of grain size,ranging from 0.9μm to 9μm,on the mechanical properties of commercially pure Mg is investigated at temperatures of 4K,78K,and *** mechanisms governing plastic flow are influenced by both grain size and *** 4K and 78K,dominant deformation modes in Mg involve dislocation glide and extension twinning,regardless of grain *** interactions between basal and non-basal dislocations and dislocations with grain boundaries promote an unusually high rate of work hardening in the plastic regime,leading to premature *** yield stress follows the Hall-Petch relationshipσ_(y)∼k/√d,with the slope k increasing with decreasing *** 298K,in addition to dislocation glide and twinning,grain boundary sliding(GBS)becomes significant in samples with grain sizes below 3μm,considerably enhancing the material’s *** activation provides an additional recovery mechanism for dislocations accumulating at grain boundaries,facilitating their absorption during sliding and *** ofσrelationship suggests that the basal slip is the dominant dislocation mode in Mg at *** grain size suppresses dislocation activity and twinning and increases GBS,resulting in lowerandσ*** conventional deformation modes coupled with enhanced GBS yields stress softening,breaking down the Hall-Petch relationship in Mg below 3μm grain size,leading to an inverse Hall-Petch *** work reports new data on the strength,ductility,work hardening and fracture behaviour,and their variations with Mg grain size across different temperature regimes.

关键词： Polycrystalline Mg Mechanical properties Deformation mechanisms Work-hardening Texture evolution Cryogenic temperatures Hall-Petch relationship

Praseodymium metal nanorods as a 5-fluorouracil carrier

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Journal of Rare Earths 2024年第7期42卷 1328-1336,I0005页

作者： Varnitha Manikantan Govindaraj Sri Varalakshmi Ujma Ashapak Tamboli Archana Sumohan Pillai Aleyamma Alexander Anushka Lucas Bose Allben Akash Israel V.M.V.Enoch centre for nanoscience and Genomics Karunya Institute of Technology and Sciences(Deemed University)Coimbatore641114Tamil NaduIndia Department of Applied Chemistry Karunya Institute of Technology and Sciences(Deemed University)Coimbatore641114Tamil NaduIndia

Interest in metal nanoparticles as nanoscale drug-carrying vehicles has been *** such an aspect,lanthanide metal nanoparticles are particularly ***,we report praseodymium nanoparticles as a novel anticancer therapeutic transporting *** material was made as a composite with the supramolecular host polymer,poly-β-*** praseodymium nanorods were characterized using standard analytical techniques,including X-ray diffraction(XRD),X-ray photoelectron spectroscopy(XPS),and thermogravimetric analysis(TGA).In addition,they were imaged using transmission electron *** nanostructures are a long rod-shaped material with 2.0±0.1μm in length and 230±10 nm in *** material shows a saturation magnetization value above 30 emu/g with a coercivity value of 130 *** nanocarrier is freighted with the drug 5-fluorouracil,and the encapsulation efficiency is 76.09%.The drug release is continuous from the nanocarrier(polymer-containing praseodymium nanoparticles)and proceeds for above 250 *** in vitro cytotoxicities of the blank nanocarrier and the 5-fluorouracil-loaded one are deduced by testing them on MCF-7 and Vero(non-cancerous)cell *** cytotoxicity on the cancerous cell lines is observed,whereas the non-cancerous cells are *** IC_(50)values on the cell lines are reported.

关键词： Metal nanoparticles Praseodymium Poly-cyclodextrin Drug delivery Anticancer activity Rare earths

Molecular Engineering of Naphthalimide Methylcyclohexane Luminogen:Unraveling J^(*)-Aggregation Pattern and Sensing Melamine in Aqueous Media

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CCS Chemistry 2024年第4期6卷 923-931页

作者： Kavita Narang Parameswar Krishnan Iyer Department of Chemistry Indian Institute of Technology GuwahatiGuwahati 781039Assam centre for nanotechnology Indian Institute of Technology GuwahatiGuwahati 781039Assam

Naphthalimide methylcyclohexane(NMICY)luminogen that features molecular conformation-directed aggregation-induced emission was prepared,and its pure equatorial conformer was isolated and wellcharacterized via various techniques,including single-crystal X-ray diffraction(SC-XRD)*** NMICY,the methyl cyclohexane substituent adapted the most stable chair conformation,preventing intermolecularπ-πinteractions among the naphthalimide *** analysis of the self-assembly behavior indicated that an uncommon J^(*)-aggregation pattern was predominant for NMICY that exhibited∼450 nm emission in crystal as well as in the aggregated state[λmax=455 nm,фPL=23.22%,fw=99.9%in water or water-dimethylformamide mixture].NMICY self-assembled into cube-shaped 2D-nanoarchitecture as characterized by fieldemission scanning electron microscopy,atomic force microscopy,and dynamic light scattering(Zavg=143 nm,∼20 nm height)studies while also displaying unique optical properties in the aggregated *** supramolecular self-assembly and aggregated state structure-property relationship in aqueous media of NMICY were optimized,and a facile strategy for the detection of melamine in milk and an aqueous solution of milk powder is reported with a limit of detection value of 0.184 ppm(milk)and 0.101 ppm(milk powder),achieved via the rare acceptor-excited photoinduced electron transfer ***,a smartphone-based,portable,and uncomplicated sensing platform was developed that simplifies the melamine detection process.

关键词： conformational isomers J^(*)-aggregation aggregation-induced emission supramolecular assembly melamine detection acceptor-excited photoinduced electron transfer mechanism