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npj Computational Materials 2023年第1期9卷 1023-1038页

作者： Dongil Shin ryan Alberdi Ricardo A.Lebensohn Rémi Dingreville Center for Integrated Nanotechnologies Sandia National LaboratoriesAlbuquerqueNM 87185USA Simulation Modeling Sciences Sandia National LaboratoriesAlbuquerqueNM 87185USA Theoretical Division Los Alamos National LaboratoryLos AlamosNM 87845USA

Recent developments integrating micromechanics and neural networks offer promising paths for rapid predictions of the response of heterogeneous materials with similar accuracy as direct numerical *** deep material network is one such approaches,featuring a multi-layer network and micromechanics building blocks trained on anisotropic linear elastic *** trained,the network acts as a reduced-order model,which can extrapolate the material’s behavior to more general constitutive laws,including nonlinear behaviors,without the need to be ***,current training methods initialize network parameters randomly,incurring inevitable training and calibration ***,we introduce a way to visualize the network parameters as an analogous unit cell and use this visualization to“quilt”patches of shallower networks to initialize deeper networks for a recursive training *** result is an improvement in the accuracy and calibration performance of the network and an intuitive visual representation of the network for better explainability.

关键词： networks Deep network

A comparison of centrifugation and tangential flow filtration for nanoparticle purification: A case study on acetalated dextran nanoparticles

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Particuology 2020年第3期18卷 189-196页

作者： Nishan K.Shah ryan Ivone Jie Shen Samantha A.Meenach University of Rhode Island College of PharmacyDepartment of Biomedical and Pharmaceutical SciencesKingstonRI 02881USA University of Rhode Island College of EngineeringDepartment of Chemical EngineeringKingstonRI 02881USA

Tangential fiow filtration (TFF) is a purification method commonly used in a multitude of fields,including particle ***,there is still a lack of comprehensive understanding of the effects of key TFF parameters on nanoparticle (NP) characteristics (purification outcomes).The present study aimed to investigate the influence of various factors on the characteristics of TFF-purified *** most commonly used NP purification method,centrifugation,was studied as a control.A design of experiment approach was implemented to investigate the influence of transmembrane pressure,flow rate,and initial drug loading on NP characteristics using paclitaxel as a model small *** the determination of optimized TFF parameters,the two purification methods were assessed using other model small molecules (*** and resveratrol).The results indicated that the TFF parameters and initial loading of the drug played important roles in the purified NP *** with the centrifugation method,TFF resulted in smaller NP with higher drug *** was able to circumvent issues associated with conventional centrifugation,while yielding similar results,and can potentially serve as a suitable large-scale purification method for polymeric NP.

关键词： Tangential flow filtration Nanoparticle purification Box-Behnken design Acetalated dextran Drug delivery

Getting started in endoscopic ear surgery

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Journal of Otology 2020年第1期15卷 6-16页

作者： Peter ryan Carolina Wuesthoff Nirmal Patel Department of Otolaryngology and Head and Neck Surgery Royal North Shore HospitalSt LeonardsNSWAustralia Kolling Deafness Research Centre Macquarie University and University of SydneyNSWAustralia cSydney Endoscopic Ear Surgery Research Group Department of Otolaryngology-Head&Neck SurgeryFaculty of Medicine and Health SciencesMacquarie UniversitySydneyAustralia Discipline of Surgery Sydney Medical SchoolUniversity of SydneyAustralia

Endoscopic ear surgery(EES) is an exciting, rapidly developing and innovative field of otologic *** and conceptually, EES is a significant departure from traditional microscopic transcanal approaches to the middle ear and canal that has shown very positive results with respect to patient outcomes. This review serves as a primer for the otologist and otology resident embarking on EES and discusses the theory surrounding the learning process, the optical chain for endoscopic surgery as well as other important underlying principles.

关键词： Endoscopic Endoscopic Ear Surgery Optical Chain

Nitrogen further promotes a dominant salt marsh plant in an increasingly saline environment

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Journal of Plant Ecology 2012年第4期5卷 429-441页

作者： Amelia Byrd ryan Katharyn E.Boyer Romberg Tiburon Center for Environmental Studies San Francisco State University3152 Paradise DriveTiburonCA 94920USA Department of Biology San Francisco State University1600 Holloway AvenueSan FranciscoCA 94132 USA

Aims Human alterations of the environment are combining in unprecedented ways,making predictions of alterations to natural communities a difficult and pressing *** systems have been subject to a high degree of modification,including increased nitrogen(N)inputs and altered salinity,factors important in shaping estuarine plant *** human populations increase and the climate changes,both N and salinity levels are likely to increase in these coastal *** objective was to evaluate the interactive effects of N and salinity on USWest Coast salt marsh species;in particular,the performance of the dominant species Sarcocornia pacifica(pickleweed)alone and in mixed species *** expected increased salinity to favor *** but that N enrichment could help maintain greater species richness through use of N in salinity tolerance *** We crossed treatments of N(added or not)and salinity(salt added or not)in a field experiment at a salt marsh in the San Francisco Estuary,California,USA,in each of three habitats:(i)monotypic pickleweed on the marsh plain,(ii)monotypic pickleweed along channels and(iii)mixed assemblages along *** a greenhouse experiment,we crossed treatments of N(added or not)and salinity(at three levels to simulate brackish to saline conditions)in(i)pots of pickleweed only and(ii)the same species mix as in the *** Findings Naddition doubled *** biomass and branching in both channel and marsh plain habitats regardless of salinity and greatly increased its dominance over Distichlis spicata and Jaumea carnosa in mixed assemblages along *** the greenhouse,*** biomass increased 6-to 10-fold with N addition over the range of salinities,while *** and *** biomass increased with N addition only at lower salinity ***,while localized management could influence outcomes,expected overall increases in both N and salinity with human population growth and climat

关键词： Distichlis eutrophication Jaumea salinity Sarcocornia

Optimal Control of Nonlinear Switched Systems:Computational Methods and Applications

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Journal of the Operations Research Society of China 2013年第3期1卷 275-311页

作者： Qun Lin ryan Loxton Kok Lay Teo Department of Mathematics and Statistics Curtin UniversityPerthAustralia

A switched system is a dynamic system that operates by switching between different subsystems or *** systems exhibit both continuous and discrete characteristics—a dual nature that makes designing effective control policies a challenging *** purpose of this paper is to review some of the latest computational techniques for generating optimal control laws for switched systems with nonlinear dynamics and continuous inequality *** discuss computational strategies for optimizing both the times at which a switched system switches from one mode to another(the so-called switching times)and the sequence in which a switched system operates its various possible modes(the so-called switching sequence).These strategies involve novel combinations of the control parameterization method,the timescaling transformation,and bilevel programming and binary relaxation *** conclude the paper by discussing a number of switched system optimal control models arising in practical applications.

关键词： Switched system Nonlinear system Optimal control Nonlinear optimization

A New Method for Determining Fluid Compositions in the H_2O-NaClCaCl_2 System with Cryogenic Raman Spectroscopy

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Acta Geologica Sinica(English Edition) 2014年第4期88卷 1169-1182页

作者： CHI Guoxiang CHU Haixia ryan SCOTT CHOU I-Ming Department of Geology University of Regina Laboratory for Experimental Study Under Deep-sea Extreme Conditions Sanya Institute of Deep-sea Science and EngineeringChinese Academy of Sciences

Raman peaks of various hydrates in the H20-NaCl-CaCl2 system have been previously identified, but a quantitative relationship between the Raman peaks and XNaCl （i.e.,NaCl/ （NaCl＋CaCl2）） has not been established, mainly due to the difficulty to freeze the solutions. This problem was solved by adding alumina powder to the solutions to facilitate nucleation of crystals. Cryogenic （-185℃） Raman spectroscopic studies of alumina-spiced solutions indicate that XNaCl is linearly correlated with the total peak area fraction of hydrohalite. Capsules of solutions made from silica capillary were prepared to simulate fluid inclusions. Most of these artificial fluid inclusions could not be totally frozen even at temperatures as low as -185℃, and the total peak area fraction of hydrohalite is not correlated linearly with XNaCI. However, the degree of deviation （△XNaCl） from the linear correlation established earlier is related to the amount of residual solution, which is reflected by the ratio （r） of the baseline ＂bump＂ area, resulting from the interstitial unfrozen brine near 3435 cm^-1, and the total hydrate peak area between 3350 and 3600 cm^-1. A linear correlation between △XNaCl and r is established to estimate XNaCl from cryogenic Raman spectroscopic analysis for fluid inclusions.

关键词： cryogenic Raman H20-NaCl-CaCl2 XNaCI fluid inclusion

In-situ probing of thermal desorption of vapor molecules on a nanowire via work function variance

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Nano Research 2016年第11期9卷 3334-3345页

作者： Kovur Prashanthi John Eric Hawk ryan McGee Ravi Gaikwad Thomas Thundat Ingenuity Lab Department of Chemical and Materials Engineering University of Alberta Edmonton AB T6G 2V4 Canada

Nanowire sensors based on variations of their electrical properties show great potential for real-time, in situ monitoring of molecular adsorption and desorption. Although the molecular adsorption-induced change in the electronic work function is very sensitive, it does not have any specificity. However, the temperature dependency of the adsorption-induced work function variation can provide limited selectivity based on the desorption temperature. In this study, we report the in situ probing of molecular desorption by monitoring the work function variations of a single Pt nanowire as a function of temperature. The work function of a clean Pt nanowire shows a significant variation due to vapor adsorption at room temperature. Increasing the temperature of the nanowire results in a variation of the work function due to molecular desorption. Experimentally measured differential work function as a function of temperature shows desorption peaks at 36 and 44 ℃ for methanol and ethanol molecules respectively. Adsorption-induced variation of the Pt nanowire work function was further confirmed using ultraviolet photoelectron spectroscopy before and after exposure to methanol vapor. These results show that the molecular adsorption/desorption-induced variation of the work function and its temperature dependency can be used for developing nanoscale electro-calorimetric sensors.

关键词： Kelvin probe microscopy nanowires thermal desorption work function

Molecular regulation of sucrose catabolism and sugar transport for development~ defence and phloem function

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Journal of Integrative Plant Biology 2017年第5期59卷 322-335页

作者： Jun Li Limin Wu ryan Foster Yong-Ling Ruan Australia-China Research Centre for Crop Improvement and School of Environmental and Life Sciences The University of NewcastleNSW 2308 Australia CSIRO Agriculture Canberra ACT 26oi Australia

Sucrose （Suc） is the major end product of photosynthesis in mesophyll cells of most vascular plants. It is loaded into phloem of mature leaves for long-distance translocation to non-photosynthetic organs where it is unloaded for diverse uses. Clearly, Suc transport and metabolism is central to plant growth and development and the functionality of the entire vascular system. Despite vast information in the literature about the physiological roles of individual sugar metabolic enzymes and transporters, there is a lack of systematic evaluation about their molecular regulation from transcriptional to post-translational levels. Knowledge on this topic is essential for understanding and improving plant development, optimizing resource distri- bution and increasing crop productivity. We therefore focused our analyses on molecular control of key players in Suc metabolism and transport, including：（i） the identifica- tion of promoter elements responsive to sugars and hormones or targeted by transcription factors and micro- RNAs degrading transcripts of target genes; and （ii） modulation of enzyme and transporter activities through protein-protein interactions and other post-translational modifications. We have highlighted major remaining questions and discussed opportunities to exploit current understanding to gain new insights into molecular control of carbon partitioning for improving plant performance.

关键词： William J. Lucas University of California Davis USA

The impact of attractants on pocket gopher trapping

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Current Zoology 2014年第4期60卷 472-478页

作者： Roger A. BALDWIN ryan MEINERZ Steve B. ORLOFF Department of Wildlife Fish and Conservation Biology University of California-Davis Davis CA 95616 USA University of California Cooperative Extension 1655 South Main Street Yreka CA 96097 USA

Pocket gophers （Geomyidae） have an extensive impact on both natural and agricultural systems. Trapping is a tech- nique often used to sample and manage these populations. The identification of an attractant that increases capture rates of pocket gophers would greatly assist researchers and pest management professionals alike. Therefore, we tested the attractiveness of four attractants （peanut butter, anise, grapefruit attractant, and carrot） plus a control （no attractant） using uncovered and covered trap sets to determine what impact they have on visitation and capture rates of pocket gophers. We also determined how the impact of cover status and attractants differ across varying weights and gender of pocket gophers. We found no direct effect of any attracrant on visitation and capture rates of pocket gophers, nor on the gender of captured individuals. However, when no attractant was used, the mtmber of pocket gophers captured per 100 trap nights was greater when trap sets were uncovered vs. when covered, and capture rates were generally high and consistent when using peanut butter as an attractant. Additionally, we noted that covered trap sets that were baited with peanut butter yielded heavier pocket gopher captures than uncovered trap sets using this same attractant. This is key, given the difficulty associated with capturing older, more experienced individuals. Combined with data from a previous investigation, this suggests that there is no advantage to using any attractant when utilizing uncovered trap sets, but there is likely some benefit to using peanut butter in covered trap sets [Current Zoology 60 （4）： 472-478, 2014].

关键词： Attractant Demographics Pocket gopher Thomomys bottae Thomomys talpoides Trapping

Superconvergence and the Numerical Flux: a Study Using the Upwind-Biased Flux in Discontinuous Galerkin Methods

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Communications on Applied Mathematics and Computation 2020年第3期2卷 461-486页

作者： Daniel J.Frean Jennifer K.ryan School of Mathematics University of East AngliaNorwichUK Applied Mathematics and Statistics Colorado School of MinesGoldenCOUSA

One of the beneficial properties of the discontinuous Galerkin method is the accurate wave propagation *** is,the semi-discrete error has dissipation errors of order 2k+1(≤Ch2k+1)and order 2k+2 for dispersion(≤Ch2k+2).Previous studies have concentrated on the order of accuracy,and neglected the important role that the error constant,C,plays in these *** this article,we show the important role of the error constant in the dispersion and dissipation error for discontinuous Galerkin approximation of polynomial degree k,where k=0,1,2,*** gives insight into why one may want a more centred flux for a piecewise constant or quadratic approximation than for a piecewise linear or cubic *** provide an explicit formula for these error *** is illustrated through one particular flux,the upwind-biased flux introduced by Meng et al.,as it is a convex combination of the upwind and downwind *** studies of wave propagation are typically done through a Fourier *** higher order Fourier information can be extracted using the smoothness-increasing accuracy-conserving(SIAC)*** SIAC filter ties the higher order Fourier information to the negative-order norm in physical *** show that both the proofs of the ability of the SIAC filter to extract extra accuracy and numerical results are unaffected by the choice of flux.

关键词： Discontinuous Galerkin Smoothness-increasing accuracy-conserving(SIAC)filtering Superconvergence