检索结果-南通市图书馆

Frontiers of Materials Science 2019年第4期13卷 389-398页

作者： Kaushik DAS C.A.KUMAR leonardo MIRANDOLA Maurizio CHIRIVAJNTERNATI Jharna CHAUDHURI Department of Mechanical Engineering Texas Tech UniversityLubbockTX 79409USA Department of Physics and Astronomy University of Texas at San AntonioSan AntonioTX 78249USA Department of Atomic and Molecular Physics Manipal UniversityManipal 576104KarnatakaIndia Department of Natural and Physical Sciences Northwest Vista College3535 N Ellison DrSan AntonioTX 78251USA Kiromic BioPharma 7707 Fannin St.Suite 140Houston.TX 77054USA Department of Gastroenterology Hepatology and NutritionUniversity of Texas MD Anderson Cancer CenterHoustonTX 77030USA Department of Mechanical and Materials Engineering PO Box 751Portland State UniversityPortlandOR 97207-0751USA

Upconversion nanoparticles(UC NPs)in combination with plasmonic materials have great potential for cancer photothermal ***,sodium holmium fluoride(NaHoF4)is being investigated for luminescence and magnetic resonance imaging(MRI)contrast ***,we present successful synthesis of excellent quality doped NaHoF4 NPs for possible UC luminescence application and coated for possible photothermal therapy *** NaHoF4 nanocrystals were doped with Yb/Er and coated with gold,gold/silica,silver and polypyrrole(PPy).XRD,XPS and TEM were used to determine structure and morphology of the *** UC photoluminescence(PL)emission spectra were obtained from the NPs when excited by near-infrared(NIR)light at 980 *** viability and toxicity of the NPs were characterized using pancreatic and ovarian cancer cells with results showing that gold/silica coating produced least toxicity followed by gold coating.

关键词： photothermal therapy upconversion photoluminescence nanoparticle sodium holmium fluoride

Effect of Sn precursor on the synthesis of SnO2 and Sb-doped SnO2 particles via polymeric precursor method

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Frontiers of Materials Science 2013年第4期7卷 387-395页

作者： Francisco LOPEZ MORALES Teresa ZAYAS Oscar E. CONTRERAS leonardo SALGADO Department of Chemistry Metropolitan Autonomous University- Iztapalapa P.O. Box 55-534 C.P. 09340 Mexico D.F. Mexico Postgraduate in Environmental Sciences and Center of Chemistry of the Science Institute Meritorious Autonomous University of Puebla P.O. Box 1613 C.P. 72000 Puebla Mexico Center of Nanoscience and Nanotechnology Department of Nanostructures P.O. Box 14 C.P. 22800 Ensenada B.C. Mexico

SnO2 and Sb-doped SnO2 particles were synthesized using the polymeric precursor method with different Sn salt precursors： SnCl2.2H2O, SnCl4.5H20, or Sn citrate. Sb2O3 was used as the precursor of Sb, and the molar ratio of nsn：nsb was held constant. FTIR and TGA/DTA were used to examine the influence of the Sn precursor on the formation and thermal decomposition of the Sn and Sn-Sb complexes. The calcination products obtained from heating the Sn and Sn-Sb complexes at 500℃ in air were analyzed using XRD and TEM analysis. The results revealed that the SnO2 and Sb-doped SnO2 formation temperatures depended on the nature of the Sn precursor. The calcination products were found to be SnO2 and Sb-doped SnO2 particles, which crystallized in a tetragonal cassiterite structure with a highly preferred （110） planar orientation. The Sn precursor and the presence of Sb in the SnO2 matrix strongly influenced the crystallinity and lattice parameters.

关键词： SnO2 and Sb-doped SnO2 Sn precursor Pechini method thermal decomposition nanoparticle

维普期刊数据库

Learning the Mapping x→Σi=1^d xi^(2):the Cost of Finding the Needle in a Haystack

在线全文

学校读者我要写书评

暂无评论

Communications on Applied Mathematics and Computation 2021年第2期3卷 313-335页

作者： Jiefu Zhang leonardo Zepeda-Nunez Yuan Yao Lin Lin Department of Mathematics University of CaliforniaBerkeleyBerkeleyCA 94720USA Department of Mathematics University of Wisconsin-MadisonMadisonWI 53706USA Department of Mathematics Hong Kong University of Science and TechnologyClear Water BayKowloonHong KongChina Computational Research Division Lawrence Berkeley National LaboratoryBerkeleyCA 94720USA

The task of using the machine learning to approximate the mapping x→Σi=1^d xi^(2)with Xi∈[-1,1]seems to be a trivial *** the knowledge of the separable structure of the function,one can design a sparse network to represent the function very accurately,or even *** such structural information is not available,and we may only use a dense neural network,the optimization procedure to find the sparse network embedded in the dense network is similar to finding the needle in a haystack,using a given number of samples of the *** demonstrate that the cost(measured by sample complexity)of finding the needle is directly related to the Barron norm of the *** only a small number of samples are needed to train a sparse network,the dense network trained with the same number of samples exhibits large test loss and a large generalization *** control the size of the generalization gap,we find that the use of the explicit regularization becomes increasingly more important as d *** numerically observed sample complexity with explicit regularization scales as G(d^(2.5)),which is in fact better than the theoretically predicted sample complexity that scales as 0(d^(4)).Without the explicit regularization(also called the implicit regularization),the numerically observed sample complexity is significantly higher and is close to 0(d^(4.5)).

关键词： Machine learning Sample complexity Generalization error

Quantitative estimation of bubble volume fraction of submarine seep plumes by modeling seismic oceanography data

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Oceanology and Limnology 2023年第2期41卷 673-686页

作者： Tonggang HAN Jiangxin CHEN leonardo AZEVEDO Bingshou HE Huaning XU Rui YANG Key Lab of Submarine Geosciences and Prospecting Techniques Ministry of EducationOcean University of ChinaQingdao 266100China Key Laboratory of Gas Hydrate Ministry of Natural ResourcesQingdao Institute of Marine GeologyQingdao 266071China Laboratory for Marine Mineral Resources Pilot National Laboratory for Marine Science and Technology(Qingdao)Qingdao 266237China CERENA DECivilInstituto Superior TécnicoUniversidade de LisboaAv.Rovisco PaisLisbon 1049-001Portugal

Submarine seep plumes are a natural phenomenon in which different types of gases migrate through deep or shallow subsurface sediments and leak into seawater in pressure *** detected using acoustic data,the leaked gases frequently exhibit a flame-like *** numerically modelled the relationship between the seismic response characteristic and bubble volume fraction to establish the bubble volume fraction in the submarine seep *** show that our models are able to invert and predict the bubble volume fraction from field seismic oceanography data,by which synthetic seismic sections in different dominant frequencies could be numerically simulated,seismic attribute sections(e.g.,instantaneous amplitude,instantaneous frequency,and instantaneous phase)extracted,and the correlation between the seismic attributes and bubble volume fraction be quantitatively determined with functional *** instantaneous amplitude is positively correlated with bubble volume fraction,while the instantaneous frequency and bubble volume fraction are negatively *** addition,information entropy is introduced as a proxy to quantify the relationship between the instantaneous phase and bubble volume *** the bubble volume fraction increases,the information entropy of the instantaneous phase increases rapidly at the beginning,followed by a slight upward trend,and finally ***,under optimal noise conditions,the bubble volume fraction of submarine seep plumes can be inverted and predicted based on seismic response characteristics in terms of seismic attributes.

关键词： seismic oceanography submarine seep plumes bubble volume fraction seismic response characteristics seismic attribute analysis quantitative analysis

维普期刊数据库

First record of Odontaster penicillatus populations(Philippi,1870)(Echinodermata:Asteroidea)in the Atacama and Antofagasta regions,Chile(Southeast Pacific)

在线全文

学校读者我要写书评

暂无评论

Acta Oceanologica Sinica 2022年第12期41卷 152-155页

作者： leonardo Campos Fernando Berrios Brenda BHermosillo-Núñez Marco Ortiz Departamento de Ciencias Acuáticas y Ambientales Universidad de Antofagasta ChileAntofagasta 1240000Chile Centro de Investigaciones Costeras Universidad de Atacama(CIC-UDA) Avenida Copayapu 485Copiapó1530000Chile Laboratorio de Modelamiento de Sistemas Ecológicos Complejos(LAMSEC) Instituto AntofagastaUniversidad de AntofagastaAntofagasta 1240000Chile Instituto de Ciencias Naturales AvH Facultad de Ciencias del Mar y Recursos BiológicosUniversidad de AntofagastaAntofagasta 1240000Chile Centro de Investigación y Estudios Avanzados del Maule Vicerrectoría de Investigación y PosgradoUniversidad Católica Del MauleCampus San MiguelTalca 3480094Chile

We report for the first time the presence of local populations of the starfish Odontaster penicillatus in the regions of Atacama and Antofagasta,*** finding indicates an extension of the distribution limit of 500 km with respect to the last observation made in 2007 in Isla Grande de Atacama.A total of 121 specimens of *** were recorded at depths of between 8 m and 24 *** were associated with rocky substrate and with different species of barnacles,sponges and *** presence of *** expands the knowledge of the benthic biodiversity of the region,and the development of studies on its ecological importance will be promoted.

关键词： Odontaster penicillatus new record Antofagasta Atacama South Pacific Ocean

维普期刊数据库

Self-healing and SDN:bridging the gap

在线全文

学校读者我要写书评

暂无评论

Digital Communications and Networks 2020年第3期6卷 354-368页

作者： leonardo Ochoa-Aday Cristina Cervell o-Pastor Adriana Fernaandez-Fernaandez Department of Network Engineering Universitat Politecnica de Catalunya(UPC)Esteve Terradas708860CastelldefelsSpain

Achieving high programmability has become an essential aim of network research due to the ever-increasing internet ***-Defined Network(SDN)is an emerging architecture aimed to address this ***,maintaining accurate knowledge of the network after a failure is one of the largest challenges in the *** by this reality,this paper focuses on the use of self-healing properties to boost the SDN *** approach,unlike traditional schemes,is not based on proactively configuring multiple(and memory-intensive)backup paths in each switch or performing a reactive and time-consuming routing computation at the controller ***,the control paths are quickly recovered by local switch actions and subsequently optimized by global controller *** results show that the proposed approach recovers the control topology effectively in terms of time and message load over a wide range of generated ***,scalability issues of traditional fault recovery strategies are avoided.

关键词： Software-defined network Autonomic network management Protocol design Fault tolerance Network management

Unveiling the detection dynamics of semiconductor nanowire photodetectors by terahertz near-field nanoscopy

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Light(Science & Applications) 2020年第1期9卷 184-195页

作者： Eva A.A.Pogna Mahdi Asgari Valentina Zannier Lucia Sorba leonardo Viti Miriam S.Vitiello NEST CNR-Istituto Nanoscienze and Scuola Normale SuperiorePiazza San Silvestro 1256127 PisaItaly

Semiconductor nanowire field-effect transistors represent a promising platform for the development of roomtemperature(RT)terahertz(THz)frequency light detectors due to the strong nonlinearity of their transfer characteristics and their remarkable combination of low noise-equivalent powers(100 V/W).Nano-engineering an NW photodetector combining high sensitivity with high speed(subns)in the THz regime at RT is highly desirable for many frontier applications in quantum optics and nanophotonics,but this requires a clear understanding of the origin of the *** electrical and optical measurements,however,cannot unambiguously determine the dominant detection mechanism due to inherent device asymmetry that allows different processes to be simultaneously ***,we innovatively capture snapshots of the photo-response of individual InAs nanowires via high spatial resolution(35 nm)THz photocurrent *** coupling a THz quantum cascade laser to scattering-type scanning near-field optical microscopy(s-SNOM)and monitoring both electrical and optical readouts,we simultaneously measure transport and scattering *** spatially resolved electric response provides unambiguous signatures of photo-thermoelectric and bolometric currents whose interplay is discussed as a function of photon density and material doping,therefore providing a route to engineer photo-responses by design.

关键词： scattering quantum frontier

Novel protective penile collar following inflatable penile prosthesis placement: the “Wang Collar”

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Asian Journal of Andrology 2020年第5期22卷 481-484页

作者： leonardo D Borregales Jose Saavedra-Belaunde Run Wang Jonathan Clavell-Hernandez Division of Urology The University of Texas Health Science CenterHoustonTX 77030US A MD Anderson Cancer Center HoustonTX 77030U S A St.Joseph Medical Center HoustonTX 77002USA.

Penile rehabilitation after inflatable penile prosthesis(IPP)implantation for the treatment of erectile dysfunction includes leaving the device partially inflated so as to preserve the penile length and to maintain *** a partially inflated device,the penis becomes more sensitive and more susceptible to unintended insults during the immediate postoperative ***“Wang Collar,”a device intended to protect the penis in the early postoperative period,is hereby *** hundred and forty-eight patients had the 44Wang Collar"included as part of their post-1 PP management from August 2014 to February *** protective collar,devised from a polystyrene cup with the bottom removed,is secured with a tape over the previously dressed and partially inflated *** order to evaluate the effectiveness of this device,we conducted surveys on the perioperative staff at three different ***“Wang Collar”has been found to be beneficial in the early postoperative care of *** on the answers to our questionnaire,the perioperative personnel found this device to be highly protective,especially when transporting the patient after IPP surgery,easy to work with,and almost never bothersome or irritative to the *** present a novel penile device after IPP placement,which we have found to improve patient satisfaction in the postoperative *** addition,it eases the care of the patient by the perioperative *** is now our routine to use this device after IPP *** research is necessary to evaluate whether this device can decrease postoperative wound complications.

关键词： erectile dysfunction inflatable penile prosthesis postoperative dressing

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

The MPEG-4 Standard

通信学报 1998年第9期 55-68页

作者： leonardo Chiariglioneleonardo Chiariglione:MPEG Convener CSELT-Italy

１ＩｎｔｒｏｄｕｃｔｉｏｎＩｎｔｈｅｌａｓｔ２０ｙｅａｒｓｔｈｅｗｏｒｌｄｏｆａｕｄｉｏａｎｄｖｉｄｅｏｈａｓｕｎｄｅｒｇｏｉｎｇｒａｐｉｄｃｈａｎｇｅｓ．Ｔｈｅｆｉｒｓｔｖｉｄｅｏｃｏｎｆｅｒｅｎｃｅｓｙｓｔｅｍ（... 详细信息

１ＩｎｔｒｏｄｕｃｔｉｏｎＩｎｔｈｅｌａｓｔ２０ｙｅａｒｓｔｈｅｗｏｒｌｄｏｆａｕｄｉｏａｎｄｖｉｄｅｏｈａｓｕｎｄｅｒｇｏｉｎｇｒａｐｉｄｃｈａｎｇｅｓ．Ｔｈｅｆｉｒｓｔｖｉｄｅｏｃｏｎｆｅｒｅｎｃｅｓｙｓｔｅｍ（ＩＴＵ－ＴＲｅｃｏｍｍｅｎｄａｔｉ...

关键词： MPEG-4 Standard The

Spatial and temporal distribution of American cutaneous leishmaniasis in Acre state,Brazil

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Infectious Diseases of Poverty 2017年第1期6卷 891-899页

作者： leonardo Augusto Kohara Melchior Andreia Fernandes Brilhante Francisco Chiaravalloti-Neto Biological and Nature Science Center Federal University of AcreRio BrancoACBrazil School of Public Health University of Sao PauloSao PauloSPBrazil Department of Epidemiology School of Public HealthUniversity of Sao PauloSao PauloSPBrazil Departamento de Epidemiologia Faculdade de Saude PublicaUniversidade de Sao PauloAv.Dr.Arnaldo715CEP 01246-904Sao PauloSPBrazil

Background:Acre has reported the highest incidence of American cutaneous leishmaniasis(ACL)in Brazil in recent *** present study seeks to identify high and low risk agglomerations of ACL in space and space-time during the period from 2007 to 2013 in Acre,and also to characterize the occurrence of the disease in time and according to sociodemographic ***:This is an ecological study,the study population of which consisted of autochthonous ACL cases notified in the municipalities of Acre by an epidemiological surveillance *** statistics of SaTScan^(TM)software were used to identify spatial and space-time *** addition,the cases were characterized by sex,age,home situation(in a rural or urban area),and temporal ***:Acre reported an incidence rate of 12.4 cases per 10000 inhabitant-years in the study period,with the rates varied greatly(standard deviation of 21.8)among their 22 *** agglomeration of high risk and three of low risk were detected in space and *** of the five micro-regions of Acre presented a stationary temporal *** profile of transmission varied according to the *** speaking,the disease occurred more often among young people,those of male gender,and those living in rural ***:Acre has stood out within the Brazilian national context due to its high rates of ACL incidence in the central region of the Acre *** high rates in the micro-region of Brasileia are related to the disease’s intra/peridomiciliary occurrence,and it would seem that the municipality of Sena Madureira is approaching a transmission pattern similar to that of *** other micro-regions,the profile of the disease’s transmission is mainly related to the forest/sylvatic cycle of ACL.

关键词： Cutaneous leishmaniasis Geographical information system Spatial analysis Scan statistics Acre Brazil