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Knotting ligands to control metal coordination geometry

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Science China Chemistry 2025年第2期68卷 403-404页

作者： Fabien b.l.Cougnon Department of Chemistry and Nanoscience Centre University of JyväskyläJyväskyläFinland

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 *** properties of Zn^(Ⅱ),unlike those of any other first-row transition metal ions,explain its biological *** to its filled d-shell orbitals,Zn^(Ⅱ) is redox-stable,has a ligand-field energy stabilization of zero and,consequently,no typical coordination number and *** metalloproteins exploit these features to carry a broad range of chemical reactions in mild *** metalloenzymes,unsaturated ZnII centres often act as redox-stable lewis *** 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.

关键词： coordination geometry centre

Atmospheric chemistry of trifluorodicarbonyls initiated by Cl atoms:Reactivity trends,mechanism,and acid formation yields

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Journal of Environmental Sciences 2025年第5期151卷 12-25页

作者： Pedro l.lugo Vianni G.Straccia Cynthia b.Rivela Mariano A.Teruel María b.blanco laboratorio Universitario de Química y Contaminación del Aire(l.U.Q.C.A) Instituto de Investigaciones en Fisicoquímica de Córdoba(I.N.F.I.Q.C.)Dpto.de Fisicoquímica.Facultad de Ciencias QuímicasUniversidad Nacional de Córdoba.Ciudad Universitaria5000 CórdobaArgentina Institute for Atmospheric and Environmental Research University of WuppertalDE-42097 WuppertalGermany

Rate coefficients of the gas-phase reactions of Cl atoms with a series of fluorinated diketones(FDKs):CF_(3)C(O)CH_(2)C(O)CH_(3)(TFP),CF_(3)C(O)CH_(2)C(O)CH_(2)CH_(3)(TFH)and CF_(3)C(O)CH_(2)C(O)CH(CH_(3))2(TFMH),have been measured at(298±2)K and under atmospheric *** experiments were performed using the relative-rate method with a GC-FID detection *** different determinations and references used,the following rate coefficients were obtained(in cm3/(molecule·sec)):k_(4)(TFP+Cl)=(1.75±0.21)×10^(−10),k_(5)(TFH+Cl)=(2.05±0.23)×10^(−10),k_(6)(TFMH+Cl)=(2.71±0.34)×10^(−10).Reactivity trends of FDKs were discussed and Free Energy Relationships analysis was *** expression lgkOH=1.68 lgkCl+5.71 was obtained for the reactivity of the studied FDKs together with similar unsaturated VOCs with Cl and OH radicals Additionally,acetic acid(CH_(3)C(O)OH)and trifluoroacetic acid(CF_(3)C(O)OH)were positively identified and quantified as degradation products using in situ FTIR *** to the identified products,atmospheric chemical mechanisms were *** atmospheric implications of the studied reactions were assessed by the estimation of the tropospheric lifetimes of TFP,TFH,and TFMH concerning their reaction with Cl atoms to be 48,41,and 31 hours,*** relatively short residence in the atmosphere of the fluorocarbons studied will have a local/regional impact with restricted *** warming potential(GWP(20 yr))calculated for the studied fluoro diketones were 0.014,0.003 and 0.001 for TFP,TFH and TFMH,respectively with a negligible contribution to the greenhouse effect.

关键词： Fluorinated diketones Kinetics SPME-GC-FID FTIR in situ SAR Free energy relationships

Kinetics of the reaction of OH radical with ethylfluoroacetate,ethyl 4,4,4-trifluorobutyrate,and butylfluoroacetate

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Journal of Environmental Sciences 2025年第5期151卷 273-283页

作者： Pedro l.lugo Vianni Straccia Mariano A.Teruel María b.blanco laboratorio Universitario de Química y Contaminación del Aire(l.U.Q.C.A) Institute for Research in Physical Chemistry of Córdoba(I.N.F.I.Q.C.)Department of Physical ChemistryFaculty of Chemical SciencesNational University of CórdobaUniversity CityCórdoba 5000Argentina Institute for Atmospheric and Environmental Research University of WuppertalWuppertal DE-42097Germany

Kinetics of the gas-phase reactions of•OH radicals with a series of fluoroesters were studied for the first time at 298±3 K and atmospheric *** rate coefficients were determined by in situ FTIR spectroscopy in nitrogen and GC-FID in air to monitor the decay of reactants and *** following coefficient values(in 10^(−12)cm^(3)/(molecule•sec))were obtained for ethyl fluoroacetate(EFA),ethyl 4,4,4-trifluorobutyrate(ETb),and butyl fluoroacetate(bFA),respectively:k_(1)(EFA+OH)=1.15±0.25 by FTIR and 1.34±0.23 by GC-FID;k_(2)(ETb+OH)=1.61±0.36 by FTIR and 2.02±0.30 by GC-FID;k_(3)(bFA+OH)=2.24±0.37 by *** trends were developed and correlated with the number of CH_(3)and F substituents in the fluoroester,and structure-activity relationships(SARs)calculations were *** addition,the tropospheric lifetimes of EFA,ETb,and bFA upon degradation by OH radicals were calculated to be 9,6,and 5 days,respectively,indicating that these fluorinated compounds could have a possible regional effect from the emission *** small photochemical ozone creation potentials of 9,7,and 19 were estimated for EFA,ETb,and bFA,*** GlobalWarming Potentials(GWPs)for EFA,ETb,and bFA were calculated for different time *** a 20-year time horizon,the GWPs were 1.393,0.063,and 0.062,*** the case of a 100-year time horizon,the GWPs were 0.379,0.017,and 0.017,and for a 500-year time horizon,the GWPs were 0.108,0.005,and 0.005 for EFA,ETb,and bFA.

关键词： CFC replacements sinks in situ FTIR SAR Acidification potentials Greenhouse gases

ECHOS OF THE STEINER-lEHMUS EQUAl bISECTORSSTHEOREM

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Acta Mathematica Scientia 2025年第1期45卷 257-263页

作者： Christoph bÖRGERS Eric l.GRINbERG Mehmet ORHON Junhao SHEN Department of Mathematics Tufts UniversityMedfordMA02155USA Department of Mathematics University of Massachusetts BostonBostonMA02125USA Department of Mathematics&Statistics University of New HampshireDurhamNH03824USA

The Steiner-lehmus equal bisectors theorem originated in the mid 19th *** its age,it would have been accessible to Euclid and his *** theorem remains evergreen,with new proofs continuing to appear *** theorem has fostered discussion about the nature of proof itself,direct and *** we continue the momentum by providing a trigonometric proof,relatively short,based on an analytic estimate that leverages algebraic trigonometric *** proofs of the theorem exist in the *** of these contain key ideas that already appeared in ***’1850 proofs,not always with *** the aim of increasing awareness of and making more accessible lehmus’proofs,we provide an annotated *** conclude with remarks on different proofs and relations among them.

关键词： Steiner-lehmus theorem equal bisectors

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Schwarzschild black hole surrounded by a cloud of strings in the background of perfect fluid dark matter

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Chinese Physics C 2025年第02期 224-240页

作者： b.Hamil b.C.lütfüo?lu laboratoire de Physique Mathématique et Subatomique Faculté des Sciences ExactesUniversité Constantine 1 Department of Physics Faculty of ScienceUniversity of Hradec Kralove

This manuscript investigates a Schwarzschild black hole surrounded by perfect fluid dark matter embedded in a cloud of strings. The effects of its surroundings on thermodynamics, timelike and null geodesics, shadows,and quasinormal modes are analyzed. It is demonstrated that changes in spacetime, induced by the surrounding environment, significantly influence the stability, thermal phases, energy dynamics, particle trajectories, and observable features of the black hole's shadow, as well as its oscillation frequency and decay rate.

关键词：

A Search on Dirac Equation

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Chinese Physics letters 2007年第11期24卷 3024-3027页

作者： M. Kocak, b. gonül Department of Engineering Physics Faculty of Engineering University of Gaziantep 27310 Gaziantep Turkey

The solutions, in terms of orthogonal polynomials, of Dirac equation with analytically solvable potentials are investigated within a novel formalism by transforming the relativistic equation into a Schrodinger-like one. Earlier results are discussed in a unified framework, and some solutions of a large class of potentials are given.

关键词： coated conductor buffer layer self-epitaxy CeO2

Morphology and phylogeny of two species of bathypathes from the tropical western Pacific,with description of a new species

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Journal of Oceanology and limnology 2025年第1期43卷 248-260页

作者： Ting lÜ Zifeng ZHAN Kuidong XU laboratory of Marine Organism Taxonomy and Phylogeny Qingdao Key Laboratory of Marine Biodiversity and ConservationInstitute of OceanologyChinese Academy of SciencesQingdao 266071China laboratory for Marine biology and biotechnology Laoshan LaboratoryQingdao 266237China University of Chinese Academy of Sciences Beijing 100049China

The black coral genus bathypathes brook,1889 represents a relatively diverse and ecologically important assemblage comprising the deep-sea hard substrate *** phylogenetic investigations have revealed the polyphyletic nature of bathypathes,urging further morphological analysis to understand its *** combing morphological and molecular data,we describe bathypathes multifurcata *** report *** Molodtsova,Opresko&Wagner,2022based on the specimens collected from the tropical western *** phylogenetic topology reconstructed using nuclear ITS1-5.8S-ITS2 and three mitochondrial fragments suggests the separation of bathypathes into four *** analysis of morphological characters,particularly the colony branch and pinnule patterns also roughly classify bathypathes into four morphological groups A–*** A is characterized by the unbranched colony and the subopposite arrangement of *** contrast to Group A,Groups b–D have the alternately arranged *** these,Group C exhibits a distinctly long unpinnulated stem compared to Groups b and *** b has unbranched colony,relatively short unpinnulated stem,and spines on pinnules have blunt *** Group D,large colonies(higher than 40 cm)have one or a few branches,small colonies(less than 40 cm)are unbranched,and spines on pinnules have acute *** data particularly those species without sequences are necessary to verify the classification of these groups.

关键词： Antipatharia black coral taxonomy phylogeny seamount western Pacific

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b2-CuZr reinforced amorphous alloy matrix composites:A review

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China Foundry 2025年第1期22卷 1-11页

作者： Wei Guo Run-hua Huang Zhen Zhang Mi Zhao Jin-cheng Wang Yan-qiang Qiao Shu-lin lü Shu-sen Wu State Key lab of Materials Processing and Die&Mould Technology School of Materials Science and EngineeringHuazhong University of Science and TechnologyWuhan 430074China State Key laboratory of Solidification Processing Northwestern Polytechnical UniversityXi’an 710072China School of Aerospace Engineering Huazhong University of Science and TechnologyWuhan 430074China Research Institute of Huazhong University of Science and Technology in Shenzhen Shenzhen 518057GuangdongChina

b2-CuZr phase reinforced amorphous alloy matrix composites has become one of the research hotspots in the field of materials science due to the“transformation-induced plasticity”phenomenon,which makes the composites show better macroscopic plastic deformability and obvious work-hardening behavior compared to the conventional amorphous alloy matrix composites reinforced with ductile ***,the in-situ metastable b2-CuZr phase tends to undergo eutectoid decomposition during solidification,and the volume fraction,size,and distribution of b2-CuZr phase are difficult to control,which limits the development and application of these *** date,much efforts have been made to solve the above problems through composition optimization,casting parameter tailoring,and post-processing *** this study,a review was given based on relevant studies,focusing on the predictive approach,reinforcing mechanism,and microstructure tailoring methods of b2-CuZr phase reinforced amorphous alloy matrix *** research focus and future prospects were also given for the future development of the present composite system.

关键词： amorphous alloy matrix composite b2-CuZr phase plasticity microstructure tailoring

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Intrumer:A Multi Module Distributed Explainable IDS/IPS for Securing Cloud Environment

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Computers, Materials & Continua 2025年第1期82卷 579-607页

作者： Nazreen banu A S.K.b.Sangeetha Department of Computer Science and Engineering SRM Institute of Science and TechnologyVadapalani CampusChennai600026Tamil NaduIndia

The increasing use of cloud-based devices has reached the critical point of cybersecurity and unwanted network *** environments pose significant challenges in maintaining privacy and *** approaches,such as IDS,have been developed to tackle these ***,most conventional Intrusion Detection System(IDS)models struggle with unseen cyberattacks and complex high-dimensional *** fact,this paper introduces the idea of a novel distributed explainable and heterogeneous transformer-based intrusion detection system,named INTRUMER,which offers balanced accuracy,reliability,and security in cloud settings bymultiplemodulesworking together within *** traffic captured from cloud devices is first passed to the TC&TM module in which the Falcon Optimization Algorithm optimizes the feature selection process,and Naie bayes algorithm performs the classification of *** selected features are classified further and are forwarded to the Heterogeneous Attention Transformer(HAT)*** this module,the contextual interactions of the network traffic are taken into account to classify them as normal or malicious *** classified results are further analyzed by the Explainable Prevention Module(XPM)to ensure trustworthiness by providing interpretable *** the explanations fromthe classifier,emergency alarms are transmitted to nearby IDSmodules,servers,and underlying cloud devices for the enhancement of preventive *** experiments on benchmark IDS datasets CICIDS 2017,Honeypots,and NSl-KDD were conducted to demonstrate the efficiency of the INTRUMER model in detecting network trafficwith high accuracy for different *** outperforms state-of-the-art approaches,obtaining better performance metrics:98.7%accuracy,97.5%precision,96.3%recall,and 97.8%*** results validate the robustness and effectiveness of INTRUMER in securing diverse cloud environments against sophisticated cyber threats.

关键词： Cloud computing intrusion detection system transformers and explainable artificial intelligence(XAI)