检索结果-南通市图书馆

Symbology of Feynman integrals from twistor geometries

在线全文

学校读者我要写书评

暂无评论

Science China(Physics,Mechanics & Astronomy) 2024年第3期67卷 44-59页

作者： song He Jiahao Liu Yichao Tang Qinglin Yang School of Fundamental Physics and Mathematical Sciences Hangzhou Institute for Advanced StudyUCASHangzhou 310024China CAS Key Laboratory of Theoretical Physics Institute of Theoretical PhysicsChinese Academy of SciencesBeijing 100190China International Centre for Theoretical Physics Asia-Pacific Beijing 100049 Peng Huanwu Center for Fundamental Theory Hefei 230026China School of Physical Sciences University of Chinese Academy of SciencesBeijing 100049China

We study the symbology of planar Feynman integrals in dimensional regularization by considering geometric configurations in momentum twistor space corresponding to their leading singularities(LS). Cutting propagators in momentum twistor space amounts to intersecting lines associated with loop and external dual momenta, including the special line associated with the point at infinity, which breaks dual conformal symmetry. We show that cross-ratios of intersection points on these lines, especially those on the infinity line, naturally produce symbol letters for Feynman integrals in D = 4-2., which include and generalize their LS. At one loop, we obtain all symbol letters using intersection points from quadruple cuts for integrals up to pentagon kinematics with two massive corners, which agree perfectly with canonical differential equation(CDE) results. We then obtain all two-loop letters, for up to four-mass box and one-mass pentagon kinematics, by considering more intersections arising from two-loop cuts. Finally we comment on how cluster algebras appear from this construction, and importantly how we may extend the method to non-planar integrals.

关键词： Feynman integrals symbol letters twistor geometry

Emerging interactively stretchable electronics with optical and electrical dual-signal feedbacks based on structural color materials

在线全文

学校读者我要写书评

暂无评论

Nano Research 2024年第3期17卷 1837-1855页

作者： Jialin Wang Kai Zhao Changqing Ye Yanlin song School of Materials Science and Engineering Suzhou University of Science and TechnologySuzhou 215009China Key Laboratory of Green Printing Institute of ChemistryChinese Academy of SciencesBeijing 100190China

The booming development of wearable devices has aroused increasing interests in flexible and stretchable *** mechanosensory functionality,these devices are highly desirable on account of their wide range of applications in electronic skin,personal healthcare,human–machine interfaces and ***,they are mostly limited by single electrical signal feedback,restricting their diverse applications in visualized mechanical *** by the mechanochromism of structural color materials,interactively stretchable electronics with optical and electrical dual-signal feedbacks are recently emerged as novel sensory platforms,by combining both of their sensing mechanisms and ***,recent studies on interactively stretchable electronics based on structural color materials are *** a brief introduction of their basic components(i.e.,stretchable electronics and mechanochromic structural color materials),two types of interactively stretchable electronics with respect to the nanostructures of mechanochromic materials are outlined,focusing primarily on their design considerations and fabrication ***,the main challenges and future perspectives of these emerging devices are discussed.

关键词： stretchable electronics structural color materials interactive sensing mechanochromism dual-signal feedbacks

Finely regulated luminescent Ag-In-Ga-S quantum dots with green-red dual emission toward white light-emitting diodes

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Opto-Electronic Advances 2024年第9期7卷 54-63页

作者： Zhi Wu Leimeng Xu Jindi Wang Jizhong song Key Laboratory of Materials Physics of Ministry of Education Laboratory of Zhongyuan LightSchool of PhysicsZhengzhou UniversityDaxue Road 75Zhengzhou 450052China

Ag-In-Ga-S(AIGS)quantum dots(QDs)have recently attracted great interests due to the outstanding optical properties and eco-friendly components,which are considered as an alternative replacement for toxic Pb-and Cd-based ***,enormous attention has been paid to how to narrow their broadband spectra,ignoring the application advantages of the broadband *** this work,the AIGS QDs with controllable broad green-red dual-emission are first reported,which is achieved through adjusting the size distribution of QDs by controlling the nucleation and growth of AIGS ***,the AIGS QDs exhibit broad dual-emission at green-and red-band evidenced by photoluminescence(PL)spectra,and the PL relative intensity and peak position can be finely ***,the dual-emission is the intrinsic characteristics from the difference in confinement effect of large particles and tiny particles confirmed by temperature-dependent PL ***,the AIGS QDs(the size consists of 17 nm and 3.7 nm)with 530 nm and 630 nm emission could successfully be synthesized at 2.0°*** combining the blue light-emitting diode(LED)chips and dual-emission AIGS QDs,the constructed white light-emitting devices(WLEDs)exhibit a continuous and broad spectrum like natural sunlight with the Commission Internationale de l’Eclairage(CIE)chromaticity coordinates of(0.33,0.31),a correlated color temperature(CCT)of 542. K,color rendering index(CRI)of 90,and luminous efficacy of radiation(LER)of 12. lm/W,which indicates that the AIGS QDs have huge potential for lighting applications.

关键词： quantum dots Ag-In-Ga-S dual emission white light-emitting diodes

A Novel Scalable Fault-Tolerant Control Design for DC Microgrids With Nonuniform Faults

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

IEEE/CAA Journal of Automatica Sinica 2024年第8期11卷 1886-1888页

作者： Aimin Wang Minrui Fei Dajun Du Yang song Shanghai Key Laboratory of Power Station Automation Technology the School of Mechatronic Engineering and AutomationShanghai UniversityShanghai 200072China

Dear Editor,The existing control schemes for microgrids(MGs)face challenges in effectively addressing plugging in/out operations under uncertain power lines and *** tackle this issue,this letter proposes a novel scalable fault-tolerant control(FTC)strategy for DC *** developing a structured Lyapunov matrix(SLM),a decoupled FTC method is introduced to mitigate the adverse effects of uncertain lines and nonuniform ***,global stability is ensured by deriving local rules expressed as linear matrix inequalities(LMIs)that solely depend on local *** new distributed generation unit(DGU)introduces only one additional condition of this nature,allowing the stability rules to scale with topology ***,the effectiveness of the proposed scheme is illustrated through simulations conducted using the MATLAB/SimPowerSystems toolbox.

关键词： stability letter operations

Modular synthesis of β-amino acids from alkenes,amines,and CO_(2. via photoredox/copper dual catalysis

在线全文

学校读者我要写书评

暂无评论

Science China Chemistry 2024年第6期67卷 1756-1757页

作者： Lei song Jie Wu Department of Chemistry National University of SingaporeSingapore117543Singapore National University of Singapore(Chongqing)Research Institute Chongqing401120China

The conversion of industrial waste into value-added chemicals represents a compelling approach to bolster sustainability *** the primary components of greenhouse gases,carbon dioxide(CO_(2.)stands as an ideal C_(1) so... 详细信息

关键词： catalysis synthesis amines

New Benthic Fossils from the Late Ediacaran Strata of Southwestern China

在线全文

学校读者我要写书评

暂无评论

Acta Geologica Sinica(English Edition) 2024年第2期98卷 311-323页

作者： LIU Junping LI Ming TANG Feng ZHAO Jiangtai song Sicun ZHOU Ying song Xiaohan REN Liudong School of Earth Science and Resources China University of GeosciencesBeijing 10083China Yunnan Institute of Geological Survey Kunming 650216China Chinese Academy of Geological Sciences Beijing 10037China Key Laboratory for Stratigraphy and Paleontology MNRCBeijing 10037China School of Earth Science and Engineering Nanjing UniversityNanjing 210093China Department of Earth Sciences University College LondonLondon WC1E 6BTU.K. CAS and Shandong Province Key Laboratory of Experimental Marine Biology Center for Ocean Mega-ScienceInstitute of OceanologyChinese Academy of SciencesQingdaoShandong 266071China Institute of Geology Chinese Academy of Geological SciencesBeijing 10037China

The Jiangchuan Biota from the Jiucheng Member(Mb.)of the Dengying Formation(Fm.),discovered in Jiangchuan,eastern Yunnan,China,is marked by copious macrofossils at the apex of the Ediacaran *** fauna features benthic algae with varied holdfasts and other fossils of indeterminate taxonomic affinity and is compositionally unique compared to the Shibantan and Gaojiashan biotas of the Dengying *** the Miaohe and Wenghui biotas of the Doushantuo Fm.,elsewhere in *** novel benthic saccular macroalgal fossil,named here Houjiashania yuxiensis *** ***.,from the Jiangchuan Biota is based on fossils that are sausage-shaped,elongate,tubular,ranging from 0.3 to 4 cm in length,and up to 0.8 cm in *** terminus is blunt and rounded to an obtuse angle,the other is bent with a spread-out surface resembling a holdfast,suggesting a three-dimensional ***,stipe-shaped outgrowths,likely vestiges of sessile saccular life forms,are prevalent in macroalgal fossils of analogous size and shape,as well as present brown algae Scytosiphonaceae,such as Colpomenia and *** new findings augment the diversity of benthic algae,such as those known from the Early Neoproterozoic Longfengshan Biota in North *** benthic algal macrofossils in the Jiucheng *** to knowledge of Late Ediacaran metaphyte diversification and offer more clues about the evolutionary positioning of primitive *** co-occurrence of numerous planktonic and benthic multicellular algae and planktonic microbes might have facilitated ecologically the more extensive later Cambrian explosion evidenced by the Chengjiang Biota in Yunnan.

关键词： paleophytology benthic saccular algae algal evolution Neoproterozoic Jiucheng Member Jiangchuan Biota Yunnan Province

Biochar-based composites for removing chlorinated organic pollutants: Applications, mechanisms, and perspectives

在线全文

学校读者我要写书评

暂无评论

Environmental Science and Ecotechnology 2024年第5期21卷 47-61页

作者： Qingqing song Fanying Kong Bing-Feng Liu Xueting song Hong-Yu Ren State Key Laboratory of Urban Water Resource and Environment School of EnvironmentHarbin Institute of TechnologyHarbin150090China School of Water Conservancy and Civil Engineering Northeast Agricultural UniversityHarbin150030China

Chlorinated organic pollutants constitute a significant category of persistent organic pollutants due to their widespread presence in the environment,which is primarily attributed to the expansion of agricultural and industrial *** pollutants are characterized by their persistence,potent toxicity,and capability for long-range dispersion,emphasizing the importance of their eradication to mitigate environmental *** conventional methods for removing chlorinated organic pollutants encompass advanced oxidation,catalytic oxidation,and bioremediation,the utilization of biochar has emerged as a prominent green and efficacious method in recent *** we review biochar's role in remediating typical chlorinated organics,including polychlorinated biphenyls(PCBs),triclosan(TCS),trichloroethene(TCE),tetrachloroethylene(PCE),organochlorine pesticides(OCPs),and chlorobenzenes(CBs).We focus on the impact of biochar material properties on the adsorption mechanisms of chlorinated *** review highlights the use of biochar as a sustainable and eco-friendly method for removing chlorinated organic pollutants,especially when combined with biological or chemical *** facilitates electron transfer efficiency between microorganisms,promoting the growth of dechlorinating bacteria and mitigating the toxicity of chlorinated organics through ***,biochar can activate processes such as advanced oxidation or nano zero-valent iron,generating free radicals to decompose chlorinated organic *** observe a broader application of biochar and bioprocesses for treating chlorinated organic pollutants in soil,reducing environmental ***,for water-based pollutants,integrating biochar with chemical methods proved more effective,leading to superior purification *** review contributes to the theoretical and practical application of biochar for removing environmental chlorinated organic pollutants.

关键词： Biochar Chlorinated organic pollutants Polychlorinated biphenyls Triclosan Trichloroethene

Toeplitz Operators and Carleson Measures for Weighted Bergman Spaces Induced by Regular Weights

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Acta Mathematica Sinica,English Series 2024年第5期40卷 1345-1359页

作者： Jun Tao DU song Xiao Hasi WULAN Department of Mathematics Guangdong University of Petrochemical TechnologyMaoming 525000P.R.China Department of Mathematics Shantou UniversityShantou 515063P.R.China

In this paper,we give a universal description of the boundedness and compactness of Toeplitz operator T_(μ)^(ω)between Bergman spaces A_(η)^(p)and A_(υ)^(q)whenμis a positive Borel measure,1 详细信息

In this paper,we give a universal description of the boundedness and compactness of Toeplitz operator T_(μ)^(ω)between Bergman spaces A_(η)^(p)and A_(υ)^(q)whenμis a positive Borel measure,1

关键词： Bergman space Carleson measure Toeplitz operator regular weight

Narrative as“legal tender”:the semiotic meanings of“exchange”in Malcolm Bradbury’s Rates of Exchange

在线全文

学校读者我要写书评

暂无评论

Language and Semiotic Studies 2024年第3期10卷 343-366页

作者： Yanfang song School of Foreign Languages Soochow UniversitySuzhouChina

Malcolm Bradbury’s novel Rates of Exchange,taking the economic term“rates of exchange”as a central metaphor,depicts various exchanges occurring in the socio-economic landscape of Britain during the 1970s and *** the context of governmental emphasis on economic development,the novel intricately explores exchanges among diverse entities,playing with multiple meanings of the term“exchange”.In this way,the novel itself becomes a form of“legal tender,”exchanged for reader comprehension,communication,and *** highlights the ubiquitous presence of exchange and the risks associated with the uncertain exchange rates between different ***,it invites readers to participate in the story-telling and the nostalgic journey back to British literary *** paper,drawing on Roland Barthes’s semiotic theory along with structuralist and poststructuralist concepts,investigates the multifaceted meanings of“exchange”in the *** this analysis,the paper aims to illuminate the semiotic significance of various narrative forms and the profound thematic concerns in Bradbury’s work.

关键词： Rates of Exchange narrative Roland Barthes semiotics