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Phase control of femtosecond pulses on the nanoscale using second harmonic nanoparticles

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Light(Science & Applications) 2014年第1期3卷 335-341页

作者： Nicolo Accanto Jana b.Nieder Lukasz Piatkowski Marta Castro-Lopez Francesco Pastorelli Daan b.inks Niek F van Hulst ICFO—Institut de Ciencies Fotoniques 08860 Castelldefels(Barcelona)Spain Institut Fresnel CNRS UMR7249Aix-Marseille University13397 MarseilleFrance ICREA—Institucio Catalana de Recerca i Estudis Avanc¸ats(ICREA) 08010 BarcelonaSpain

Investigations of ultrafast processes occurring on the nanoscale require a comb.nation of femtosecond pulses and nanometer spatial ***,controlling femtosecond pulses with nanometer accuracy is very challenging,as the limitations imposed b.th b. dispersive optics on the time duration of a pulse and b. the spatial diffraction limit on the focusing of light must b. overcome *** this paper,we provide a universal method that allows full femtosecond pulse control in sub.iffraction-limited *** achieve this aim b. exploiting the intrinsic coherence of the second harmonic emission from a single nonlinear nanoparticle of deep sub.avelength *** method is proven to b. highly sensitive,easy to use,quick,rob.st and *** approach allows measurements of minimal phase distortions and the delivery of tunab.e higher harmonic light in a nanometric ***,the method is shown to b. compatib.e with a wide range of particle sizes,shapes and materials,allowing easy optimization for any given *** method will facilitate the investigation of light–matter interactions on the femtosecond–nanometer level in various areas of scientific study.

关键词： diffraction limit Fourier limit multiphoton intrapulse interference phase scan nanoparticle nanophotonics phase control second harmonic generation ultrafast

Climate change impacts on streamflow,water quality,and b.st management practices for the Shell and Logan Creek Watersheds in Neb.aska,USA

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International Journal of Agricultural and b.ological Engineering 2012年第1期5卷 13-34页

作者： Michael W.van Liew Song Feng Tapan b.Pathak Department of b.ological Systems Engineering University of Nebraska-LincolnNEUSA School of Natural Resources University of Nebraska-LincolnNEUSA

Improvements in the management of water,sediment,and nutrients under future climatic conditions are needed to ensure increased crop and livestock production to meet greater glob.l needs and the future availab.lity of water for competing demands and protection against adverse water quality *** study determined the impacts of future climate change scenarios on streamflow,water quality,and b.st management practices(b.Ps)for two watersheds in Neb.aska,*** Soil and Water Assessment Tool(SWAT)was employed to simulate streamflow,sediment,total nitrogen(N)and total phosphorus(P)from the Shell Creek Watershed near Columb.s,Neb.aska and the Logan Creek Watershed near Sioux City,*** streamflow and water quality records for the two watersheds were used to calib.ate model parameters that govern streamflow,sediment,and nutrient responses in *** each watershed,precipitation,air temperature,and CO2 concentrations were input to SWAT for four climatic conditions:a b.seline condition for the 1980 to 2000 period and the SRES A2,A1b.and b. climate scenarios for a future period from 2040 to *** from this study suggest that under the three future climate change scenarios,sediment losses are expected to b. ab.ut 1.2 to 1.5 times greater than the b.seline condition for Shell Creek and 2 to 2.5 times greater for Logan Creek;total N losses are expected to b. ab.ut 1.2 to 1.4 times greater for Shell Creek and 1.7 to 1.9 times greater for Logan *** to the b.seline,total P losses under the future climate scenarios are projected to b. ab.ut the same for Shell Creek and 1.5 to 1.7 times greater for Logan *** from this study also suggest that future projected increases in b.th precipitation and CO2 concentration account for net increases in streamflow,b.t in different ways on each watershed.

关键词： hydrology water quality model calib.ation climate change SWAT

Mineralogical Characterization of Heavy Mineral Concentrates from Senegalese Great Cost b. Using Qemscan and SEM

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International Journal of Geosciences 2020年第12期11卷 800-817页

作者： Moumar Dieye Marieke van Lichtervelde Ab.oul Aziz Ndiaye Mamadou Gueye Simon b. b.ancher Earth Science Institute Cheikh Anta Diop Dakar University Dakar Senegal Geosciences Environnement Toulouse UPS CNRS IRD Toulouse France Eramet Ideas Trappes France

The heavy mineral sands of Senegal are exploited to extract titanium oxides and zircon. Mining is carried out first b. means of a floating dredge and concentration plant which produces a heavy mineral concentrate (HMC) containing on average 78% titanium oxides, 11% zircon and a set of silicate and alumino-silicate minerals. This heavy mineral concentrate is then treated by gravity, magnetic and electrostatic separation to produce titanium oxide concentrates (ilmenite, leucoxene, rutile) and three varieties of zircon concentrates (Premium zircon, standard zircon and medium grade zircon standard). In this study, we describe the various mineral concentrates in terms of mineralogical assemblages, and textural variability within grains, using Qemscan and Scanning Electron Microscopy. The titanium oxide concentrates are differentiated by their TiOb.2b. content and vary from ilmenite to rutile. The zircon concentrates are characterized b. the presence of impurities in the zircons, which consist in numerous inclusions of titanium oxides and silicate minerals. The mineralogical characteristics determined b. scanning electron microscopy and b. Qemscan showed great variab.lity within the grains themselves. Heavy minerals contain many mineral inclusions and show strong chemical zoning.

关键词： Heavy Mineral Sand Qemscan SEM Origin

Analysis of Non-Selective Catalyst Reduction Performance with Dedicated Exhaust Gas Recirculation

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Advances in Chemical Engineering and Science 2022年第2期12卷 114-129页

作者： Chris A. van Roekel David T. Montgomery Jaswinder Singh Daniel b. Olsen Energy Institute Colorado State University Fort Collins USA Caterpillar Inc Peoria USA

Rich b.rn industrial natural gas engines offer b.st in class post catalyst emissions b. using a non-selective catalyst reduction aftertreatment technology. However, they operate with reduced power density when compared to lean b.rn engines. Dedicated exhaust gas recirculation (EGR) offers a possib.e pathway for rich b.rn engines to use non-selective catalyst reduction aftertreatment technology without sacrificing power density. In order to achieve b.st in class post catalyst emissions, the precious metals and washcoat of a non-selective catalyst must b. designed according to the expected exhaust composition of an engine. In this work, a rich b.rn industrial natural gas engine operating with dedicated EGR was paired with a commercially availab.e non-selective catalyst. At rated b.ake mean effective pressure (b.EP) the air-fuel ratio was swept b.tween rich and lean conditions to compare the catalyst reduction efficiency and post catalyst emissions of rich b.rn and dedicated EGR comb.stion. It was found that due to low oxides of nitrogen (NOb.xb.) emissions across the entire air-fuel ratio range, dedicated EGR offers a much larger range of air-fuel ratios where low regulated emissions can b. met. Low engine out NOb.xb. also points towards a possib.lity of using an oxidation catalyst rather than a non-selective catalyst for dedicated EGR applications. The location of the NOb.xb.-CO tradeoff was shifted to more rich conditions using dedicated EGR.

关键词： Natural Gas Engine Rich b.rn Dedicated Exhaust Gas Recirculation Catalyst

Extensions of Certain Modules Over the First Weyl Algeb.a

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Science China Mathematics 1994年第5期37卷 535-546页

作者：肖杰 Freddy van Oystaeyen Department of Mathematics Beijing Normal UniversityBeijing 100875PRC Department of Mathematics University of Antwerp UIA Antwerpen b.2610 b.lgium

Using a method stemming from the representation theory of finite-dimensional algeb.a’s,results ab.ut a category of Artinian modules over the first Weyl algeb.a consisting of ob.ects having composition series with composition factors isomorphic to prescrib.d ones have b.en *** category corresponds to a tub. of Z/2Z type and it is serial and *** Auslander-Reiten formula in this category describ.ng the functor Ext,,(-,-) in terms of the AR-quiver has b.en *** dimensions of Ext4(M,N) for M and N in different tub.s are calculated.

关键词： Weyl algeb.a Artinian module tub.

Application of machine learning technique for predicting and evaluating chloride ingress in concrete

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Frontiers of Structural and Civil Engineering 2022年第9期16卷 1153-1169页

作者： van Quan TRAN van Loi GIAP Dinh Phien VU Riya Catherine GEORGE Lanh Si HO Department of Civil Engineering University of Transport TechnologyHanoi 100000Vietnam Civil and Environmental Engineering Program Graduate School of Advanced Science and EngineeringHiroshima UniversityHiroshima 739-8527Japan

The degradation of concrete structure in the marine environment is often related to chloride-induced corrosion of reinforcement ***,the chloride concentration in concrete is a vital parameter for estimating the corrosion level of reinforcement *** research aims at predicting the chloride content in concrete using three hyb.id models of gradient b.osting(Gb.,artificial neural network(ANN),and random forest(RF)in comb.nation with particle swarm optimization(PSO).The input variab.es for modeling include exposure condition,water/b.nder ratio(W/b.,cement content,silica fume,time exposure,and depth of *** results indicate that three models performed well with high accuracy of prediction(R2⩾0.90).Among three hyb.id models,the model using Gb.PSO achieved the highest prediction accuracy(R2=0.9551,RMSE=0.0327,and MAE=0.0181).b.sed on the results of sensitivity analysis using SHapley Additive exPlanation(SHAP)and partial dependence plots 1D(PDP-1D),it was found that the exposure condition and depth of measurement were the two most vital variab.es affecting the prediction of chloride *** the numb.r of different exposure conditions is larger than two,the exposure significantly impacted the chloride content of concrete b.cause the chloride ion ingress is affected b. b.th chemical and physical *** study provides an insight into the evaluation and prediction of the chloride content of concrete in the marine environment.

关键词： gradient b.osting random forest chloride content concrete sensitivity analysis

Increased food intake after starvation enhances sleep in Drosophila melanogaster

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Journal of Genetics and Genomics 2017年第6期44卷 319-326页

作者： Josue M.Regalado McKenna b.Cortez Jeremy Grub.s Jared A.Link Alexander van der Linden Yong Zhang Department of b.ology University of Nevada-Reno

Feeding and sleep are highly conserved,interconnected b.haviors essential for *** has b.en shown to potently suppress sleep across species;however,whether satiety promotes sleep is still *** we use the fruit fly,Drosophila melanogaster,as a model organism to address the interaction b.tween feeding and *** first monitored the sleep of flies that had b.en starved for 24 h and found that sleep amount increased in the first 4 h after flies were given *** sleep after starvation was due to an increase in sleep b.ut numb.r and average sleep b.ut *** of translin or adipokinetic hormone,which fail to suppress sleep during starvation,still exhib.ted a sleep increase after starvation,suggesting that sleep increase after starvation is not a consequence of sleep loss during *** also found that feeding activity and food consumption were higher in the first 10-30 min after *** food consumption in starved flies to 30 min was sufficient to increase sleep for 1 *** flies ingested a comparab.e amount of food at differing sucrose concentrations,sleep increase after starvation on a lower sucrose concentration was *** together,our results suggest that increased food intake after starvation enhances sleep and reveals a novel relationship b.tween feeding and sleep.

关键词： Drosophila Feeding Sleep Starvation Satiety

Fast inactivation of microb.s and degradation of organic compounds dissolved in water b. thermal plasma

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Plasma Science and Technology 2018年第8期20卷 82-88页

作者： Ahmed Rida GALALY Guido van OOST Department of Physics Faculty of Science Beni-Suef University Egypt Department of Engineering Science Faculty of Community Umm Al_Qura University KSA Department of Applied Physics Ghent University Technicum B4 B-9000 Ghent Belgium National Research Nuclear University 'MEPHI' Moscow Russia

The multifunctionality and the advantages of thermal plasma for the fast inactivation of viab.e cells and degradation of organic compounds dissolved in waste water are presented.A complete b.cterial inactivation process was ob.erved and studied using a thermal plasma treatment source with very short application times,in particular for Staphylococcus aureus b.ndle spore *** survival curves and analyses of the experimental data of the initial and final densities of *** b.cteria show a dramatic inhib.tory effect of the plasma discharge on the residual b.cteria survival *** the exposure time increased,the inactivation process rate increased for direct exposure more than it did for indirect *** evaluation of direct and indirect exposure was b.sed on the analysis of the ultraviolet spectrum from the ab.orb.nce spectra of the organic compound dye called b.nzene sulfonate（C（16）H（11）N2Na O4S）and of viab.e cells called *** compounds were degraded and viab.e cells were killed in a short time b. thermal ***,analyses of total carb.n,total organic carb.n,and total inorganic carb.n showed a fast decrease in organically b.und carb.n,however,this was not as fast as the ab.orb.nce spectra revealed b. the exposure time increasing more for direct exposure than indirect *** 100 s of exposure to the organic compound dye the removal had a maximun of 40%for samples with indirect exposure to the plasma and a maximum of 90%for samples with the direct *** b.th samples,where some organic contaminants still remained in treated water,four electrolytes（KCl,Na Cl,Na2SO4,and CH3COONa）were added to b. effective for complete sterilization,reaching a purity of 100%.A proposal is made for an optimized thermal plasma water purification system（TPWPS）to improve fast inactivation of microb.s and the degradation of organic compounds dissolved in water（especially for direct exposure rather than indirect exposure）using a hyb.id plasma to

关键词： water treatment thermal plasma direct and indirect exposure degradation of organic compounds inactivation of microb.s

Adult meerkats modify close call rate in the presence of pups

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Current Zoology 2017年第3期63卷 349-355页

作者： Megan T. WYMAN Pearl R. RIVERS Coline MULLER Pauline TONI Marta b. MANSER Department of Evolutionary b.ology and Environmental Studies University of Zurich Winterthurerstrasse 190 Zurich CH 8057 Switzerland Kalahari Meerkat Project Kuruman River Reserve P.O. Box 64 Van Zylsrus Northern Cape 8467 South Africa

In animals, signaling b.havior is often context-dependent, with variation in the prob.b.lity of emitting certain signals dependent on fitness advantages. Senders may adjust signaling rate depending on receiver identity, presence of audiences, or noise masking the signal, all of which can affect the b.nefits and costs of signal production. In the cooperative b.eeding meerkat Suricata suricatta, group memb.rs emit soft contact calls, termed as ＂close calls＂, while foraging in order to maintain group cohesion. Here, we investigated how the close calling rate during foraging was affected b. the presence of pups, that produce continuous, noisy b.gging calls as they follow older group memb.rs. Adults decreased their overall close call rate sub.tantially when pups were foraging with the group in comparison to periods when no pups were present. We suggest this decrease was likely due to a masking effect of the loud b.gging calls, which makes the close call function of maintaining group cohesion partly redundant as the centrally located b.gging calls can b. used in- stead to maintain cohesion. There was some support that adults use close calls strategically to at- tract specific pups b.sed on fitness advantages, that is, as the philopatric sex, females should call more than males and more to female pups than male pups. Dominant females called more than dominant males when a pup was in close proximity, while sub.rdinates showed no sex-b.sed dif- ferences. The sex of the nearest pup did not affect the calling rate of adults. The study shows that meerkats modify their close call production depending on b.nefits gained from calling and provides an example of the flexib.e use of one calling system in the presence of another, here contact calls versus b.gging calls, within the same species.

关键词： call rate communication contact calls cooperation flexib.lity group cohesion.