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Wafer-scale quasi-layered tungstate-doped polypyrrole film with high volumetric capacitance

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Nano Research 2023年第4期16卷 4895-4900页

作者： Huabo Liu Jiaxing Liang john Watt richard D.Tilley Rose Amal Da-Wei Wang School of Chemical Engineering University of New South WalesSydneyNSW 2052Australia 2 Center for Integrated NanotechnologiesLos Alamos National LaboratoryLos AlamosNW 87545USA 3 School of ChemistryUniversity of New South WalesSydneyNSW 2052Australia

Layered materials are particularly attractive for supercapacitors because of their unique physical,electrical and chemical ***,we demonstrate a facile and scalable electrochemical deposition method for wafer-scale synthesis of quasilayered tungstate-doped polypyrrole films(named TALPy)with controllable thickness and *** as-prepared TALPy film exhibits a high gravimetric density and excellent volumetric capacitance,exceeding many high-performing carbon-and polymerbased film *** on combined results of ex-situ X-ray diffraction(XRD),Raman and X-ray photoelectron spectroscopy(XPS),it is determined that TALPy stores charge through an ion intercalation process accompanied by change in oxidation states of polypyrrole backbone,which is referred as intercalation *** these results suggest the great promise of electrochemical deposition as a scalable and controllable bottom-up approach for synthesizing quasi-layered conductive organic-inorganic hybrid films for electrochemical energy storage applications with high volumetric performance.

关键词： electrochemical deposition conductive polymer polypyrrole organic-inorganic hybrid supercapacitor intercalation pseudocapacitance

Polarization variability arising from clumps in the winds of Wolf-Rayet stars

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Chinese Journal of Astronomy and Astrophysics 2009年第5期9卷 558-576页

作者： Qing-Kang Li Joseph E Cassinelli john C. Brown richard Ignace Department of Astronomy Beijing Normal University Beijing 100875 China Department of Astronomy University of Wisconsin-Madison 53711 USA Department of Physics and Astronomy University of Glasgow Glasgow G12 8QQ Scotland UK Department of Physics and Astronomy Eastern Tennessee State University USA

Polarimetric and photometric variability of Wolf-Rayet （WR） stars as caused by clumps in the winds is revisited. In our model, which is improved from Li et al., radial expansion of the thickness is accounted for, but we retain dependence on the β velocity law and stellar occultation effects. We again search for parameters that can yield results consistent with observations in regards to the mean polarization p, the ratio R = σp/σphot of polarimetric to photometric variability and the volume filling factor fV. Clump generation and spatial distribution are randomized by the Monte Carlo method so as to produce clumps which are, in the mean, distributed uniformly in space and have time intervals that obey a Gaussian distribution. The generated clumps move radially outward with a velocity law determined by a β index, and the angular size of clumps is assumed to be fixed. By fitting the observed σp/σphot and the volume filling factor fv, clump velocity taw index β （- 2） and clump ejection rate .N （- 1） are inferred, and are found to be well constrained. In addition, the subpeak features of broad emission lines seem to support the clump ejection rate. Meanwhile, the fraction of total mass loss rate that is contained in clumps is obtained by fitting observed polarization. We conclude that this picture of the clumps＇ properties produces a valuable diagnostic of WR wind structure.

关键词： stars mass loss -- stars Wolf-Rayet -- stars winds, outflows

Explicit and Parameterized Episodes of Warm-Season Precipitation over the Continental United States

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Advances in Atmospheric Sciences 2006年第1期23卷 91-105页

作者： Mitchell W. MONCRIEFF john D. TUTTLE richard E. CARBONE National Center for Atmospheric Research BoulderColorado 80307-3000U. S. A.

This paper describes explicit and parameterized simulations of midsummer precipitation over the continental United States for two distinct episodes： moderate large-scale forcing and weak forcing. The objective is to demonstrate the capability of explicit convection at currently affordable grid-resolution and compare it with parameterized realizations. Under moderate forcing, 3-kin grid-resolution explicit simulations represent rainfall coherence remarkably well. The observed daily convective generation near the Continental Divide and the subsequent organization and propagation are reproduced qualitatively. The propagation speed, zonal extent and duration of the rainfall streaks compare favorably with their observed counterparts, although the streak frequency is underestimated. The simulations at -10-km grid-resolution applying conventional convective parameterization schemes also replicate reasonably well the diurnal convective regeneration in moderate forcing. The performance of the 3-km grid-resolution model demonstrates the potential of -1-km-resolution explicit cloud-resolving models for the prediction of warm season precipitation for moderately forced environments. In weak forcing conditions, however, predictions of precipitation coherence and diurnal variability are much poorer. This suggests that an even finer resolution explicit model is required to adequately treat convective initiation and upscale organization typical of the warm season over the continental U.S.

关键词： warm-season precipitation explicit simulation convective parameterization

Low-loss microwave photonics links using hollow core fibres

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Light(Science & Applications) 2022年第8期11卷 1891-1902页

作者： Xi Zhang Zitong Feng David Marpaung Eric Numkam Fokoua Hesham Sakr john richard Hayes Francesco Poletti David john richardson Radan Slavík Optoelectronics Research Centre University of SouthamptonSouthamptonSO171BJUK Laser Physics and Nonlinear Optics Group Faculty of Science and TechnologyMESA+Institute for NanotechnologyUniversity of TwenteEnschede7500 AEThe Netherlands

There are a host of applications in communications, sensing, and science, in which analogue signal transmission is preferred over today’s dominant digital transmission. In some of these applications, the advantage is in lower cost, while in others, it lies in superior performance. However, especially for longer analogue photonics links (up to 10 s of km), the performance is strongly limited by the impairments arising from using standard single-mode fibres (SSMF). Firstly, the three key metrics of analogue links (loss, noise figure, and dynamic range) tend to improve with received power, but this is limited by stimulated Brillouin scattering in SSMF. Further degradation is due to the chromatic dispersion of SSMF, which induces radio-frequency (RF) signal fading, increases even-order distortions, and causes phase-to-intensity-noise conversion. Further distortions still, are caused by the Kerr nonlinearity of SSMF. We propose to address all of these shortcomings by replacing SSMFs with hollow-core optical fibres, which have simultaneously six times lower chromatic dispersion and several orders of magnitude lower nonlinearity (Brillouin, Kerr). We demonstrate the advantages in this application using a 7.7 km long hollow-core fibre sample, significantly surpassing the performance of an SSMF link in virtually every metric, including 15 dB higher link gain and 6 dB lower noise figure.

关键词： nonlinearity microwave shortcomings

Geomechanical properties will constrain CO_(2)injection into the lower Ordovician Rose Run sandstone deep saline reservoir,Appalachian Basin,Kentucky,USA

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Journal of Rock Mechanics and Geotechnical Engineering 2021年第5期13卷 947-960页

作者： john richard Bowersox Stephen F.Greb Junfeng Zhu David C.Harris Kentucky Geological Survey University of KentuckyLexingtonKY40506-0107USA

The Kentucky Geological Survey(KGS)1 Hanson Aggregates stratigraphic research well,Carter County,Kentucky,USA,was drilled to a total depth of 1474 m as a field-scale test of potential CO2 storage reservoir properties in the Central Appalachian *** properties of the Rose Run sandstone(upper Ordovician Knox group)were tested for its suitability as a storage reservoir.A 9.8-m thick section of the Rose Run was penetrated at 1000 m drilled depth and a whole-diameter core and rotary sidewall cores were *** porosity and permeability measured in core plugs were 9.1%and 44.6 mD,*** vertical stress gradient calculated in the wellbore was 26 MPa/*** fractures in dolomites underlying and overlying the Rose Run follow the contemporary N53E Appalachian Basin stress *** Rose Run elastic geomechanical properties were calibrated to values measured in core plugs to evaluate its fracturing risk as a CO2 storage *** Young’s modulus and Poisson’s ratio values of the Rose Run were 45 GPa and 0.23,respectively,whereas Young’s modulus and Poisson’s ratio values were 77.1 GPa and 0.28,respectively,in the overlying Beekmantown dolomite,suggesting the Rose Run may fracture if overpressured during CO2 injection but be confined by the *** compressive strength measured in core plugs found the Rose Run and Beekmantown fractured at mean axial stresses of 156.5 MPa and 282.2 MPa,respectively,confirming the Beekmantown as suitable for confining CO2 injected into the Rose Run.A step-rate test was conducted in a mechanically-isolated 18.6-m interval bracketing the Rose *** Rose Run reservoir pressure was 9.3 MPa,and fracture gradient under injection was 13.6 MPa/km,suggesting step-rate testing before CO2 injection,and subsequent pressure monitoring to ensure *** the region around the KGS 1 Hanson Aggregates well is underpressured and adjacent to faulted Precambrian basement,further research is neede

关键词： Appalachian Basin Rose Run sandstone Geomechanics Carbon sequestration Step-rate testing

Analyzing biases of nitrogen contents and δ^(15)N values arising from acidified marine sediments with different CaCO_3 concentrations

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Acta Oceanologica Sinica 2018年第8期37卷 1-5页

作者： PENG Yajun LIU Dongyan WANG Yujue richard Pierre KEESING john K. Key Laboratory of Coastal Zone Environmental Processes and Ecological Remediation Yantai Institute of Coastal Zone Research Chinese Academy of Sciences School of Management Science Guizhou University of Finance and Economics State Key Laboratory of Estuarine and Coastal Research East China Normal University Littoral Environment et Sociétés UMR 7266 CNRS-Université de La Rochelle CSIRO Oceans and Atmosphere and University of Western Australia Oceans Institute Indian Ocean Marine Research Centre

In some studies, the researchers pretreated and measured organic carbon, nitrogen and their isotopes（δ^（13）C and δ^（15）N） of marine sediment together, to save costs and resources of analysis. However, the procedure of acidification to remove inorganic carbon for analysing δ^（13）C can affect the values of nitrogen and δ^（15）N, and the biases vary a lot depending on the CaCO_3 contents of sediments. In this study, the biases of total nitrogen（TN）and δ^（15）N values arising from acidified sediments were compared between the CaCO_3-poor（1%–16%） and CaCO_3-rich（20%–40%） samples. TN and δ^（15）N values were altered during acid treatment（without centrifugation） that possibly led to N-containing compounds volatilization. For CaCO_3-poor samples, acidification led to a range of 0%–40% TN losses and 0‰–2‰ shift in δ^（15）N values; and 10%–60% TN losses and 1‰–14‰ shift in δ^（15）N values for CaCO_3-rich samples. The biases from most samples exceeded the precision of the instrument（0.002% for TN and 0.08‰ for δ^（15）N）, and high biases could mislead our judgment for the environmental implication of the data. Thus,avoiding co-analysis of organic carbon, nitrogen and their isotopes（δ^（13）C and δ^（15）N） in sediments, even for CaCO_3-poor marine sediments, is necessary.

关键词： stable isotope nitrogen nitrogen CaCO3 acidification marine sediment

How to predict clinical relapse in inflammatory boweldisease patients

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World Journal of Gastroenterology 2016年第3期22卷 1017-1033页

作者： Elisa Liverani Eleonora Scaioli richard john Digby Matteo Bellanova Andrea Belluzzi Department of Medical and Surgical Sciences University of Bologna40138 BolognaItaly Department of Physiology Development and NeuroscienceUniversity of CambridgeCambridge CB2 3EGUnited Kingdom

Inflammatory bowel diseases have a natural course characterized by alternating periods of remission and relapse. Disease flares occur in a random way and are currently unpredictable for the most part. Predictors of benign or unfavourable clinical course are required to facilitate treatment decisions and to avoid overtreatment. The present article provides a literature review of the current evidence on the main clinical, genetic, endoscopic, histologic, serologic and fecal markers to predict aggressiveness of inflammatory bowel disease and discuss their prognostic role, both in Crohn's disease and ulcerative colitis. No single marker seems to be reliable alone as a flare predictor, even in light of promising evidence regarding the role of fecal markers, in particular fecal calprotectin, which has reported good results recently. In order to improve our daily clinical practice, validated prognostic scores should be elaborated, integrating clinical and biological markers of prognosis. Finally, we propose an algorithm considering clinical history and biological markers to intercept patients with high risk of clinical relapse.

关键词： Crohn's disease Ulcerative colitis Clinicalrelapse Clinical predictors Fecal calprotectin

Machine learning and price-based load scheduling for an optimal IoT control in the smart and frugal home

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Energy and AI 2021年第1期3卷 49-63页

作者： Rachneet Kaur Clara Schaye Kevin thompson Daniel C.Yee Rachel Zilz R.S.Sreenivas richard B.Sowers Department of Industrial and Enterprise Systems Engineering University of IllinoisUrbanaIL 61801USA Department of Electrical and Computer Engineering University of IllinoisUrbanaIL 61801USA Department of Mathematics and Department of Industrial and Enterprise Systems Engineering University of IllinoisUrbanaIL 61801USA

We pose and study a scheduling problem for an electric load to develop an Internet of Things(IoT)control system for power appliances,which takes advantage of real-time dynamic energy *** historical pricing data from a large *** supplier,we study and compare several dynamic scheduling policies,which can be implemented in a smart home to activate a major appliance(dishwasher,washing machine,clothes dryer)at an optimal time of the day,to minimize electricity *** formulate our scheduling task as a supervised machine learning classification problem which activates the load during one of two preferred time *** features used in the machine learning problem are hourly market,spot and day-ahead prices along with delayed label of the prior *** find that boosting tree-based algorithms outperform any other classification approach with measurable reduction of energy costs over certain types of naive and static *** observe that the delayed label has most predictive power across features,followed,on average,by spot,hourly market,and day-ahead energy *** further discuss implementation issues using a micro controller system coupled with cloud-based serverless computing and dynamic data *** test system includes an interactive voice interface via an intelligent personal assistant.

关键词： Power markets Load scheduling Machine learning Feature analysis Internet of Things Autonomous scheduling Serverless computing

Vegetation and Environment History for the Past 14 000 yr BP from Dingnan, Jiangxi Province, South China

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Journal of Integrative Plant Biology 2006年第9期48卷 1018-1027页

作者： john richard Dodson Shirene Hickson Rachel Khoo Xiao-Qiang Li Jemina Toia Wei-Jian Zhou Institute for the Environment Brunel University Uxbridge UB8 3PH England School of Earth and Geographical Sciences University of Western Australia Perth WA 6009 Australia State Key Laboratory of Loess and Quaternary Institute for Earth Environment the Chinese Academy of Sciences Xi＇an 710075 China

A Late Pleistocene-Holocene pollen, phosphorus, and charcoal record was reconstructed from a peatland in southern Jiangxi Province in southern China. The area today has a mountainous and rolling landscape with villages, small towns, and agriculture dominated by rice paddies, vegetable, and fruit gardens, as well as areas of secondary forest and pine re-afforestation. The record opens before 14 300 yr BP, with Alnus woodland dominating the wetland areas and with an open Quercus woodland on the surrounding slopes. The forest area becomes more complex from approximately 12 800 yr BP and further from 9 000 yr BP. At approximately 6 000 yr BP, there is evidence of clearing and, by 4 500-4 000 yr BP, a complete collapse in the wetland Alnus and terrestrial forest as the low-lying areas are converted to rice production. For much of the record, the occurrence of fire around the site was low, although there is evidence of regional fires. Fire was used as a tool in clearing and then used in the annual cycles of stubble burning after rice harvest. Nutrient levels, as reflected by total phosphorus in the sediment, seem to be closely related to forest changes and high values in the surface layers probably result from land-management techniques associated with agriculture. Therefore, human impact greatly altered forest cover, fire frequency, and nutrient dynamics; this has been evident for approximately 6 000 yr BP and then intensities towards the present day.

关键词： development of rice agriculture nutrient and fire history South China vegetation history