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Sexual selection and hermaphroditic organisms： Testing theory

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Current Zoology 2013年第4期59卷 579-588页

作者： Janet L. LEONARD Joseph M. Long Marine Laboratory University of California-Santa Cruz Santa Cruz CA 94019 USA

Sexual selection is widespread if not ubiquitous in hermaphroditic organisms. Although many phenomena that have been described as sexual selection in gonochores, （e.g. harem polygamy, multiple mating, elaborate courtship, even secondary sexual characters） can be found in some hermaphrodites, what is more interesting is the ways in which sexual selection in her- maphrodites may differ from dioecious taxa. In hermaphrodites, an individual＇s mating success includes its success from both sexual roles. Secondly, in many simultaneously hermaphroditic taxa there is strong evidence of sexual selection and yet the ope- rational sex ratio is 1：1, by definition. Many simultaneous hermaphrodites have elaborate courtship and genital anatomy, suggest- ing sexual selection plays an important role in reproductive success. Sperm competition and cryptic female choice mean that the number of mates acquired is not necessarily a predictor of reproductive success. Even in simultaneous hermaphrodites with re- ciprocal mating, variance in reproductive success through the male role and through the female role may differ in a population. Moreover hermaphrodites may choose to emphasize one sexual role over the other. Data suggest that the preferred role varies in hermaphrodites, which creates an opportunity to test fundamental predictions and assumptions of sexual selection theory. Hermaphrodites may vary their emphasis on one sexual role over the other either developmentally or behaviorally in response to environmental or social parameters. How they use this capability in acquiring more or higher quality mates still requires study

关键词： Sexual selection Hermaphrodites Mate choice Reproductive success

Permutation orbifolds of vertex operator superalgebras and associative algebras

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Science China Mathematics 2025年第1期 19-38页

作者： Chongying Dong Feng Xu Nina Yu Department of Mathematics University of California at Santa Cruz Department of Mathematics Huzhou University Department of Mathematics University of California at Riverside School of Mathematical Sciences Xiamen University

Let V be a vertex operator superalgebra and g =（1 2 ···k） be a k-cycle which is viewed as an automorphism of the tensor product vertex operator superalgebra V■*** this paper,we construct an explicit isomorphism from Ag(V■k) to A（V） if k is odd and to Aσ（V） if k is even where σ is the canonical automorphism of V of order 2 determined by the superspace structure of *** recover previous results by Barron（2016）and Barron and Vander Werf（2014） that there is a one-to-one correspondence between irreducible g-twisted V■k-modules and irreducible V-modules（*** σ-twisted V-modules） when k is odd（***）.This explicit isomorphism is expected to be useful in our further study on the Zhu algebra of the fixed point subalgebra.

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Intersystem crossing and exciton–defect coupling of spin defects in hexagonal boron nitride

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npj Computational Materials 2021年第1期7卷 537-544页

作者： Tyler JSmart Kejun Li Junqing Xu Yuan Ping Department of Physics University of CaliforniaSanta CruzCAUSA Lawrence Livermore National Laboratory LivermoreCAUSA Department of Chemistry and Biochemistry University of CaliforniaSanta CruzCAUSA

Despite the recognition of two-dimensional(2D)systems as emerging and scalable host materials of single-photon emitters or spin qubits,the uncontrolled,and undetermined chemical nature of these quantum defects has been a roadblock to further *** the design of extrinsic defects can circumvent these persistent issues and provide an ultimate ***,we established a complete theoretical framework to accurately and systematically design quantum defects in wide-bandgap 2D *** this approach,essential static and dynamical properties are equally considered for spin qubit *** particular,many-body interactions such as defect–exciton couplings are vital for describing excited state properties of defects in ultrathin 2D ***,nonradiative processes such as phonon-assisted decay and intersystem crossing rates require careful evaluation,which competes together with radiative *** a thorough screening of defects based on firstprinciples calculations,we identify promising single-photon emitters such as SiVV and spin qubits such as TiVV and MoVV in hexagonal boron *** work provided a complete first-principles theoretical framework for defect design in 2D materials.

关键词： defect hexagonal boron

3D printing of living bacteria electrode

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Nano Research 2020年第5期13卷 1318-1323页

作者： Megan C.Freyman Tianyi Kou Shanwen Wang Yat Li Department of Chemistry and Biochemistry University of CaliforniaSanta Cruz CA 95064USA

The capability of preparing three-dimensional(3D)printable living inks provides a unique way to harness the activity of microbes and use them in functional *** we demonstrate the incorporation of the living bacteria Shewanella Oneidensis MR-1(*** MR-1)directly into an ink used for creating 3D printed ***,*** MR-1 survives the 3D printing process by showing prominent activity in degrading the methyl orange azo *** the addition of carbon black to this ink,we further demonstrate the direct printing of a living microbial fuel cell(MFC)*** our knowledge,this is the first report on implementing 3D printed bacteria structure as a living electrode for an MFC *** capability of printing living and functional 3D bacterial structure could open up new possibilities in design and fabrication of microbial devices as well as fundamental research on the interaction between different bacterial strains,electrode materials,and surrounding environments.

关键词： Shewanella Oneidensis MR-1 microbial fuel cells 3D printing bacteria ink living electrode

Structural and Optical Properties and Emerging Applications of Metal Nanomaterials

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Journal of Materials Science & Technology 2008年第4期24卷 433-446页

作者： Tammg Y.Olson Department of Chemistry and Biochemistry University of CaliforniaSanta CruzCA 95064USA

Nanomaterials possess intriguing optical properties that depend sensitively on size, shape, and material content of the structures. Controlling such structural characteristics of the nanostructures allows the tailoring of their physical and chemical properties, e.g. optical, electronic, and catalytic, to achieve what is desired lot specific applications of interest. This review will cover the development of various shapes for silver and gold nanomaterials with emphasis on their relation to optical properties. Examples of various modern synthetic methods and characterization techniques are highlighted. The influence of the metal nanomaterial＇s shape and optical absorption on surface enhanced Raman scattering （SERS） and a final note on new emerging applications of metal nanostructures are also discussed.

关键词： Nanomaterial Metal nanostructure Optical properties Size and shape effect

Substrate effects on spin relaxation in two-dimensional Dirac materials with strong spin-orbit coupling

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npj Computational Materials 2023年第1期9卷 1880-1889页

作者： Junqing Xu Yuan Ping Department of Chemistry and Biochemistry University of CaliforniaSanta CruzCA 95064USA

Understanding substrate effects on spin dynamics and relaxation is of key importance for spin-based information ***, the key factors that determine such effects, in particular for materials with strong spin-orbit coupling (SOC), have notbeen well understood. Here we performed first-principles real-time density-matrix dynamics simulations with SOC and the electron-phonon and electron-impurity scattering for spin lifetimes (τ_(s)) of supported/free-standing germanene, a prototypical strong SOC 2DDirac material. We show that the effects of different substrates on τ_(s) can surprisingly differ by two orders of magnitude. We find thatsubstrate effects on τs are closely related to substrate-induced modifications of the SOC-field anisotropy, which changes the spin-flip scattering matrix elements. We propose a new electronic quantity, named spin-flip angle θ↑↓, to characterize spin relaxationthrough intervalley spin-flip scattering. We find that T_(s)^(-1) is approximately proportional to the averaged value of sin^(2)( θ↑↓/2 ) , whichserves as a guiding parameter of controlling spin relaxation.

关键词： material relaxation coupling

Rapid preparation of carbon-supported ruthenium nanoparticles by magnetic induction heating for efficient hydrogen evolution reaction in both acidic and alkalinemedia

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SusMat 2022年第3期2卷 335-346页

作者： Qiming Liu Bingzhang Lu Forrest Nichols Jeffrey Ko Rene Mercado Frank Bridges Shaowei Chen Department of Chemistry and Biochemistry University of CaliforniaSanta CruzCaliforniaUSA Department of Physics University of CaliforniaSanta CruzCaliforniaUSA

Ruthenium has been hailed as a competitive alternative for platinum toward hydrogen evolution reaction(HER),a critical process in electrochemical water *** this study,we successfully prepare metallic Ru nanoparticles supported on carbon paper by utilizing a novel magnetic induction heating(MIH)*** samples are obtained within seconds,featuring a Cl-enriched surface that is unattainable via conventional thermal *** best sample within the series shows a remarkable HER activity in both acidic and alkaline media with an overpotential of only-23 and-12 mV to reach the current density of 10 mA/cm^(2),highly comparable to that of the Pt/C *** studies based on density functional theory show that the excellent electrocatalytic activity is accounted by the surface metal-Cl species that facilitate charge transfer and downshift the d-band *** from this study highlight the unique advantages of MIH in rapid sample preparation,where residual anion ligands play a critical role in manipulating the electronic properties of the metal surfaces and the eventual electrocatalytic activity.

关键词： Cl-enriched surface density functional theory hydrogen evolution reaction magnetic induction heating ruthenium

The Scholar＇s Robe： Material Culture and Political Power in Early Modern China

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Frontiers of History in China 2016年第3期11卷 339-375页

作者： Minghui Hu Department of History University of California Santa Cruz Santa Cruz CA 95064 USA

This essay explores the history of the scholar＇s robe as a nexus of material culture and political power. It focuses on the controversial garment --called ren 衽-found pervasively in the Confucian canon and confirmed in archaeological findings. But for hundreds of years there have been disagreements and changes concerning which specific term is identified with which part of the robe, especially involving the use of ren in the scholar＇s robe. The bulk of my analysis deals with two prominent scholars＇ monographs on the robe： Huang Zongxi＇s Investigation of the Robe （Shenyi kao） and Jiang Yong＇s pointed rebuttal titled Mistakes in ＂Investigation of the R obe＂（ Shenyi kao wu）. The intellectual and political configurations of both works are analyzed in depth in order to contrast two options of cultural identity： Chinese superiority versus cosmopolitan universalism.

关键词： scholar's robe long garment Huang Zongxi Jiang Yong cultural identity

JWST’s eyes on an alien world

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The Innovation 2023年第3期4卷 81-82页

作者： Xi Zhang Department of Earth and Planetary Sciences University of California Santa CruzSanta CruzCA 95064USA

Our galaxy is believed to have more than a hundred billion planets,with over 5,000 of them discovered so *** these,only around 50 have unveiled their composition beyond the most prevalent hydrogen and *** is it so difficult?Unlike the exploration of planets within our Solar System where we can send probes to gather samples,studying exoplanets is more akin to wine tasting—we must rely on our sense of *** sensing is currently the only approach available for characterizing ***,planets are usually small and faint compared with their big and bright host *** a firefly in the presence of a campfire is always challenging.

关键词： galaxy stars Solar