Publications

Beam-induced back-streaming electron suppression analysis for an accelerator type neutron generator designed for 40Ar/39Ar geochronology

Nanocomposites of Titanium Dioxide and Polystyrene-Poly(ethylene oxide) Block Copolymer as Solid-State Electrolytes for Lithium Metal Batteries

There is considerable interest in developing solid electrolytes for rechargeable lithium batteries as they have the potential to increase both energy density due to incorporation of a lithium metal anode and safety of batteries due to the fact that they are nonflammable. Block copolymers with a mechanically hard non-conducting block and a soft ion-conducting block provide an avenue for obtaining highly conducting rigid solids. In this study we add surface-modified TiO2 nanoparticles to a mixture of polystyrene-block-poly(ethylene oxide) and bis(trifluoromethane)sulfonimide lithium salt. The presence of BF4− moieties on the surface of the particles was essential for obtaining macroscopically homogeneous electrolytes; macrophase separation was observed with the same nanoparticles with surfaces covered with oleic acid. The stability of these composite electrolytes against lithium metal electrodes was tested in symmetric lithium-composite electrolyte-lithium cells. The surprising result was that electrolytes with 24 wt% nanoparticles exhibited optimum stability; the amount of charge passed before dendrite formation observed in the optimized composite electrolyte was a factor of 4.7 larger than that of the neat block copolymer electrolyte. Both tensile and shear moduli of the electrolytes were non-monotonic functions of particle concentration with peaks in the vicinity of 17 to 20 wt%.

Author response for "Extracting structured seed-mediated gold nanorod growth procedures from scientific text with LLMs"

Chaos from two-coupled phase-locked loops

It is shown by experiment and by computer simulation that two mutually coupled PLLs (phase-locked loops) can become chaotic when they are operating in a marginal out-of-lock condition. i.e. when they are out-of-lock but very close to lock-in. The system is described by a fourth-order nonlinear autonomous equation. The power spectrum of the out-of-lock solution (close to lock-in) is observed to be a continuous broadband similar to that of a random signal. Moreover, the largest Lyapunov exponent is found to be positive. This chaotic regime has been observed over a large area of typical damping coefficients used in practical coupled PLL systems.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

Determination of kinetic parameters in the point defect model (PDM) for iron using electrochemical impedance spectroscopy and first-principles calculations

Exploring the Optical Transient Sky with the Palomar Transient Factory

The Palomar Transient Factory (PTF) is a wide-field experiment designed to investigate the optical transient and variable sky on time scales from minutes to years. PTF uses the CFH12k mosaic camera, with a field of view of 7.9 deg^2 and a plate scale of 1″ pixel^(-1), mounted on the Palomar Observatory 48 inch Samuel Oschin Telescope. The PTF operation strategy is devised to probe the existing gaps in the transient phase space and to search for theoretically predicted, but not yet detected, phenomena, such as fallback supernovae, macronovae, .Ia supernovae, and the orphan afterglows of gamma-ray bursts. PTF will also discover many new members of known source classes, from cataclysmic variables in their various avatars to supernovae and active galactic nuclei, and will provide important insights into understanding galactic dynamics (through RR Lyrae stars) and the solar system (asteroids and near-Earth objects). The lessons that can be learned from PTF will be essential for the preparation of future large synoptic sky surveys like the Large Synoptic Survey Telescope. In this article we present the scientific motivation for PTF and describe in detail the goals and expectations for this experiment.

Ge₂ZrO₆F₂·(H₂DAB)H₂O:¹  A 4-Connected Microporous Material with “Bow Tie” Building Units and an Exceptional Proportion of 3-Rings

ADVERTISEMENT RETURN TO ISSUEPREVCommunicationNEXTGe2ZrO6F2·(H2DAB)H2O:1 A 4-Connected Microporous Material with "Bow Tie" Building Units and an Exceptional Proportion of 3-RingsHailian Li, Mohamed Eddaoudi, Jacques Plévert, M. O'Keeffe, and O. M. YaghiView Author Information Materials Design and Discovery Group Department of Chemistry and Biochemistry Arizona State University, Tempe, Arizona 85287-1604 Department of Chemistry, University of Michigan 930 North University, Ann Arbor, Michigan 48109-1055 Cite this: J. Am. Chem. Soc. 2000, 122, 49, 12409–12410Publication Date (Web):November 23, 2000Publication History Received31 August 2000Published online23 November 2000Published inissue 1 December 2000https://pubs.acs.org/doi/10.1021/ja003228vhttps://doi.org/10.1021/ja003228vrapid-communicationACS PublicationsCopyright © 2000 American Chemical SocietyRequest reuse permissionsArticle Views641Altmetric-Citations54LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access optionsGet e-AlertscloseSupporting Info (1)»Supporting Information Supporting Information SUBJECTS:Ions,Materials,Metals,Porosity,Zeolites Get e-Alerts

The Experiment Data Depot: A Web-Based Software Tool for Biological Experimental Data Storage, Sharing, and Visualization

Although recent advances in synthetic biology allow us to produce biological designs more efficiently than ever, our ability to predict the end result of these designs is still nascent. Predictive models require large amounts of high-quality data to be parametrized and tested, which are not generally available. Here, we present the Experiment Data Depot (EDD), an online tool designed as a repository of experimental data and metadata. EDD provides a convenient way to upload a variety of data types, visualize these data, and export them in a standardized fashion for use with predictive algorithms. In this paper, we describe EDD and showcase its utility for three different use cases: storage of characterized synthetic biology parts, leveraging proteomics data to improve biofuel yield, and the use of extracellular metabolite concentrations to predict intracellular metabolic fluxes.

The Crisis and the Euro

This paper explores the different challenges that the financial crisis has posed to the Euro area and its governance. First, it examines the role of the Euro zone in the genesis of the financial crisis. Second, it critically analyzes the debates around the possibility that some euro zone members could be tempted to re establish their old national currencies. It then explores the prospects of new EU members adopting the euro. Fourth, it evaluates the ECB´s response to the crisis and the need for a single bank regulator. Finally, it speculates about the future of euro-dollar rivalry.

Multifunctional Silicon Surfaces: Reaction of Dichlorocarbene Generated from Seyferth Reagent with Hydrogen-Terminated Silicon (111) Surfaces

Insertion of dichlorocarbene (:CCl2), generated by decomposition of the Seyferth reagent PhHgCCl2Br, into the Si-H bond of a tertiary silane to form a Si-CCl2H group is an efficient homogeneous, molecular transformation. A heterogeneous version of this reaction, between PhHgCCl2Br and a silicon (111) surface terminated by tertiary Si-H bonds, was studied using a combination of surface-sensitive infrared and X-ray photoelectron spectroscopies. The insertion of dichlorocarbene into surface Si-H bonds parallels the corresponding reaction of silanes in solution, to produce surface-bound dichloromethyl groups (Si-CCl2H) covering ∼25% of the silicon surface sites. A significant fraction of the remaining Si-H bonds on the surface was converted to Si-Cl/Br groups during the same reaction, with PhHgCCl2Br serving as a halogen atom source. The presence of two distinct environments for the chlorine atoms (Si-CCl2H and Si-Cl) and one type of bromine atom (Si-Br) was confirmed by Cl 2p, Br 3d, and C 1s X-ray photoelectron spectroscopy. The formation of reactive, halogen-terminated atop silicon sites was also verified by reaction with sodium azide or the Grignard reagent (CH3MgBr), to produce Si-N3 or Si-Me functionalities, respectively. Thus, reaction of a hydrogen-terminated silicon (111) surface with PhHgCCl2Br provides a facile route to multifunctional surfaces possessing both stable silicon-carbon and labile silicon-halogen sites, in a single pot synthesis. The reactive silicon-halogen groups can be utilized for subsequent transformations and, potentially, the construction of more complex organic-silicon hybrid systems.

High titer methyl ketone production with tailored Pseudomonas taiwanensis VLB120

Efecto del Régimen de Flujos Alterado por Presas sobre la Supervivencia, Declinación Poblacional y Pérdidas en el Rango de Distribución de Ranas Reproductivas en Ríos de California

Widespread alteration of natural hydrologic patterns by large dams combined with peak demands for power and water delivery during summer months have resulted in frequent aseasonal flow pulses in rivers of western North America. Native species in these ecosystems have evolved with predictable annual flood‐drought cycles; thus, their likelihood of persistence may decrease in response to disruption of the seasonal synchrony between stable low‐flow conditions and reproduction. We evaluated whether altered flow regimes affected 2 native frogs in California and Oregon (U.S.A.) at 4 spatial and temporal extents. We examined changes in species distribution over approximately 50 years, current population density in 11 regulated and 16 unregulated rivers, temporal trends in abundance among populations occupying rivers with different hydrologic histories, and within‐year patterns of survival relative to seasonal hydrology. The foothill yellow‐legged frog (Rana boylii), which breeds only in flowing water, is more likely to be absent downstream of large dams than in free‐flowing rivers, and breeding populations are on average 5 times smaller in regulated rivers than in unregulated rivers. Time series data (range = 8 − 19 years) from 5 populations of yellow‐legged frogs and 2 populations of California red‐legged frogs (R. draytonii) across a gradient of natural to highly artificial timing and magnitude of flooding indicate that variability of flows in spring and summer is strongly correlated with high mortality of early life stages and subsequent decreases in densities of adult females. Flow management that better mimics natural flow timing is likely to promote persistence of these species and others with similar phenology.

On the Mass of the Black Hole in GS 2000+25

We present J- and K'-band (1.95-2.35 μm) photometry of the quiescent X-ray nova GS 2000+25, obtained in an attempt to constrain the mass of the compact object (MX). Combined with the mass function of 4.97 M☉, the infrared light curves imply MX ≤ 11 M☉ (90% confidence level), regardless of the evolutionary state of the secondary, for a mass ratio q of 4 < q < 30. For a secondary mass in the range M2 = 0.4-0.9 M☉ (as expected for a K dwarf companion), and assuming a negligible contribution from the disk at these wavelengths, we find MX = 8.5 ± 1.5 M☉ and an inclination of 65° ± 9°. The observed infrared color is consistent with that expected of a K dwarf secondary. If the accretion disk continuum is given by fλ ∝ λ-1.8, as observed in other quiescent X-ray novae, we constrain the accretion disk contribution to the K' flux (independently of optical estimates) to ≤12%.

Supernova 2001ch in MCG -01-54-16

Effects of electron concentration on the optical absorption edge of InN

InN films with free electron concentrations ranging from mid-1017 to mid-1020 cm−3 have been studied using optical absorption, Hall effect, and secondary ion mass spectrometry. The optical absorption edge covers a wide energy range from the intrinsic band gap of InN of about 0.7 to about 1.7 eV which is close to the previously accepted band gap of InN. The electron concentration dependence of the optical absorption edge energy is fully accounted for by the Burstein–Moss shift. Results of secondary ion mass spectrometry measurements indicate that O and H impurities cannot fully account for the free electron concentration in the films.

Spectroscopic classification of the transient ZTF19aamdmcs/AT2020nef

Mono- and diprotonation of the [(.eta.5-C5H5)Ti(W5O18)]3- and [(.eta.5-C5Me5)Ti(W5O18)]3- anions

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTMono- and diprotonation of the [(.eta.5-C5H5)Ti(W5O18)]3- and [(.eta.5-C5Me5)Ti(W5O18)]3- anionsT. M. Che, V. W. Day, L. C. Francesconi, W. G. Klemperer, D. J. Main, A. Yagasaki, and O. M. YaghiCite this: Inorg. Chem. 1992, 31, 13, 2920–2928Publication Date (Print):June 1, 1992Publication History Published online1 May 2002Published inissue 1 June 1992https://pubs.acs.org/doi/10.1021/ic00039a047https://doi.org/10.1021/ic00039a047research-articleACS PublicationsRequest reuse permissionsArticle Views217Altmetric-Citations34LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access optionsGet e-AlertscloseSupporting Info (1)»Supporting Information Supporting Information Get e-Alerts

Learning Space-Time Semantic Correspondences

We propose a new task of space-time semantic correspondence prediction in videos. Given a source video, a target video, and a set of space-time key-points in the source video, the task requires predicting a set of keypoints in the target video that are the semantic correspondences of the provided source keypoints. We believe that this task is important for fine-grain video understanding, potentially enabling applications such as activity coaching, sports analysis, robot imitation learning, and more. Our contributions in this paper are: (i) proposing a new task and providing annotations for space-time semantic correspondences on two existing benchmarks: Penn Action and Pouring; and (ii) presenting a comprehensive set of baselines and experiments to gain insights about the new problem. Our main finding is that the space-time semantic correspondence prediction problem is best approached jointly in space and time rather than in their decomposed sub-problems: time alignment and spatial correspondences.

Convergence and Divergence in the EU: Lessons from Italy

The topic of the Intereconomics/CEPS conference for which this paper was written was framed as a question: convergence or divergence in the EU? I am prepared to give an unambiguous answer. That answer is yes.