检索结果-南通市图书馆

A comparison of approaches in fitting continuum SEDs

Research in Astronomy and Astrophysics 2013年第4期13卷 420-434页

作者： Yao Liu David Madlener sebastian wolf Hong-Chi Wang Purple Mountain Observatory and Key Laboratory for Radio Astronomy Chinese Academy of Sciences Graduate University of Chinese Academy of Sciences Institut fr Theoretische Physik und Astrophysik Universitt zu Kiel

We present a detailed comparison of two approaches, the use of a precalculated database and simulated annealing （SA）, for fitting the continuum spectral energy distribution （SED） of astrophysical objects whose appearance is dominated by surrounding dust. While pre-calculated databases are commonly used to model SED data, only a few studies to date employed SA due to its unclear accuracy and convergence time for this specific problem. From a methodological point of view, different approaches lead to different fitting quality, demand on computational resources and calculation time. We compare the fitting quality and computational costs of these two approaches for the task of SED fitting to provide a guide to the practitioner to find a compromise between desired accuracy and available resources. To reduce uncertainties inherent to real datasets, we introduce a reference model resembling a typical circumstellar system with 10 free parameters. We derive the SED of the reference model with our code MC3 D at 78 logarithmically distributed wavelengths in the range [0.3 μm, 1.3 mini and use this setup to simulate SEDs for the database and SA. Our result directly demonstrates the applicability of SA in the field of SED modeling, since the algorithm regularly finds better solutions to the optimization problem than a precalculated database. As both methods have advantages and shortcomings, a hybrid approach is preferable. While the database provides an approximate fit and overall probability distributions for all parameters deduced using Bayesian analysis, SA can be used to improve upon the results returned by the model grid.

关键词： methods numerical - radiative transfer - protoplanetary disks

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Radiative transfer modeling of three T Tauri stars: selecting candidates for studying circumstellar disk evolution

引用

Research in Astronomy and Astrophysics 2013年第7期13卷 841-848页

作者： Yao Liu Hong-Chi Wang sebastian wolf David Madlener Purple Mountain Observatory&Key Laboratory for Radio Astronomy Chinese Academy of Sciences Graduate University of Chinese Academy of Sciences Institut für Theoretische Physik und Astrophysik Universitt zu Kiel

We present modeling work on three young stellar objects that are promis-ing targets for future high-resolution observations to investigate circumstellar disk evolution. The currently available data comprise the spectral energy distribution from optical to millimeter wavelengths which allow constraining the structure of the cir-cumstellar disk using self-consistent radiative transfer models. The results suggest that the assumption of well-mixed dust and gas leads to overestimation of flux in the far-infrared. Observational and theoretical arguments suggest that an overall decrease in far-infrared excess can be explained by dust settling towards the midplane. A new disk model is hence employed to take the effect of dust sedimentation into account. The extended model satisfactorily reproduces all existing observations. The three tar-gets studied here therefore deserve follow-up observations to reveal the evolutionary state of their protoplanetary disks.

关键词： circumstellar matter - planetary systems: protoplanetary disks - ra-diative transfer

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

The debris disk candidates:eleven 24μm excess stars in the Spitzer SWIRE fields

引用

Research in Astronomy and Astrophysics 2012年第5期12卷 513-528页

作者： Hong Wu Chao-Jian Wu Chen Cao sebastian wolf Jing-Yao Hu Key Laboratory of Optical Astronomy National Astronomical Observatories Chinese Academy of Sciences Beijing 100012 China Department of Astronomy Beijing Normal University Beijing 100875 China Institute of Space Science and Physics Shandong University at Weihai Weihai 264209 China Shandong Provincial Key Laboratory of Optical Astronomy ＆ Solar-Terrestrial Environment Weihai 264209 China Max Planck Institute for Astronomy K6nigstuhl 17 69117 Heidelberg Germany

We present the optical to mid-infrared SEDs of 11 debris disk candidates from Spitzer SWIRE fields. All the candidates are selected from SWIRE 24 μm sources matched with both the SDSS star catalog and the 2MASS point source catalog. They show an excess in the mid-infrared at 24 μm （Ks-[24]vega 〉 0.44）, indicating the presence of a circumstellar dust disk. The observed optical spectra show that they are all late-type main-sequence stars covering the spectral types of FGKM. Their fractional luminosities are well above 5× 10-5, even up to the high fractional luminosity of 1×10-3. The high galactic latitudes of SWIRE fields indicate that most of these candidates could belong to the oldest stars in the thick disk. Our results indicate that high fractional luminosity debris disks could exist in old solar-like star systems, though they are still quite rare. Their discovery at high galactic latitudes also provides an exellent opportunity for further study of the properties and evolution of debris disks in regions of the Galaxy with low densities of ISM, called ISM poor environments.

关键词： infrared stars -- planetary systems protoplanetary disks - stars for marion

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Homogalacturonan MethyI-Esterification and Plant Development

引用

Molecular Plant 2009年第5期2卷 851-860页

作者： sebastian wolf Gregory Mouille Jerome Pelloux Heidelberg Institute for Plant Science Im Neuenheimer Feld 360 69120 Heidelberg Germany Laboratoire de Biologie Cellulaire Institut Jean-Pierre Bourgin INRA Centre de Versailles-Grignon Route de St Cyr 78026 Versailles France EA3900-BioPI Biologie des Plantes et contrble des Insectes ravageurs Universite de Picardie 33 Rue St Leu 80039 Amiens France

The ability of a plant cell to expand is largely defined by the physical constraints imposed by its cell wall. Accordingly, cell wall properties have to be regulated during development. The pectic polysaccharide homogalacturonan is a major component of the plant primary walls. Biosynthesis and in muro modification of homogalacturonan have recently emerged as key determinants of plant development, controlling cell adhesion, organ development, and phyllotactic patterning. This review will focus on recent findings regarding impact of homogalacturonan content and methylesterification status of this polymer on plant life. Demethyl-esterification of homogalacturonan occurs through the action of the ubiquitous enzyme ＇pectin methyl-esterase＇. We here describe various strategies developed by the plant to finely tune the methyl-esterification status of homogalacturonan along key events of the plant lifecycle.

关键词： Carbohydrate metabolism cell walls Arabidopsis Pectin.

来源：

维普期刊数据库评论

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 regeneration factors ERF114 and ERF115 regulate auxin-mediated lateral root development in response to mechanical cues

引用

Molecular Plant 2022年第10期15卷 1543-1557页

作者： Balkan Canher Fien Lanssens Ai Zhang Anchal Bisht Shamik Mazumdar Jefri Heyman sebastian wolf Charles W.Melnyk Lieven De Veylder Department of Plant Biotechnology and Bioinformatics Ghent UniversityGhent B-9052Belgium VIB Center for Plant Systems Biology Ghent B-9052Belgium Department of Plant Biology Linnean Center for Plant BiologySwedish University of Agricultural SciencesAlmas alle 575651 UppsalaSweden Department of Plant Biochemistry Center for Plant Molecular Biology(ZMBP)University of Tubingen72076 TubingenGermany

Plants show an unparalleled regenerative capacity,allowing them to survive severe stress conditions,such as injury,herbivory attack,and harsh weather *** potential not only replenishes tissues and restores damaged organs but can also give rise to whole plant *** the intertwined nature of development and regeneration,common upstream cues and signaling mechanisms are largely ***,we demonstrate that in addition to being activators of regeneration,ETHYLENE RESPONSE FACTOR 114(ERF114)and ERF115 govern developmental growth in the absence of wounding or *** ERF114 and ERF115 activity enhances auxin sensitivity,which is correlated with enhanced xylem maturation and lateral root formation,whereas their knockout results in a decrease in lateral ***,we provide evidence that mechanical cues contribute to ERF114 and ERF115 expression in correlation with BZR1-mediated brassinosteroid signaling under both regenerative and developmental ***,cell wall integrity surveillance via mechanosensory FERONIA signaling suppresses their expression under both *** together,our data suggest a molecular framework in which cell wall signals and mechanical strains regulate organ development and regenerative responses via ERF114-and ERF115-mediated auxin signaling.

关键词： lateral root ERF114 mechanical stress cell wall integrity FERONIA auxin

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Millimeter gap contrast as a probe for turbulence level in protoplanetary disks

引用

Science China(Physics,Mechanics & Astronomy) 2022年第12期65卷 131-144页

作者： Yao Liu Gesa H.-M.Bertrang Mario Flock Giovanni P.Rosotti Ewine F.van Dishoeck Yann Boehler Stefano Facchini Can Cui sebastian wolf Min Fang Max-Planck-Institut für Extraterrestrische Physik Garching85748Germany Purple Mountain Observatory&Key Laboratory for Radio Astronomy Chinese Academy of SciencesNanjing210023China Max-Planck-Institut für Astronomie HeidelbergD-69117Germany Leiden Observatory Leiden UniversityLeidenNL-2300the Netherlands School of Physics and Astronomy University of LeicesterLeicesterLE17RHUK UniversitéGrenoble Alpes French National Centre for Scientific ResearchInstitute for Planetary Sciences and AstrophysicsGrenobleGrenobleF-38000France European Southern Observatory Garching85748Germany Department of Applied Mathematics and Theoretical Physics University of CambridgeCentre for Mathematical SciencesCambridgeCB3 OWAUK Institut für Theoretische Physik und Astrophysik Christian-Albrechts-Universität zu kielKiel24118Germany

Turbulent motions are believed to regulate angular momentum transport and influence dust evolution in protoplanetary *** the strength of turbulence is challenging through gas line observations because of the requirement for high spatial and spectral resolution data,and an exquisite determination of the *** this work,taking the well-known HD 163296 disk as an example,we investigated the contrast of gaps identified in high angular resolution continuum images as a probe for the level of *** self-consistent radiative transfer models,we simultaneously analyzed the radial brightness profiles along the disk major and minor axes,and the azimuthal brightness profiles of the B67 and B100 *** fitting all the gap contrasts measured from these profiles,we constrained the gas-to-dust scale height ratioΛto be 3.0^(+0.3)_(−0.8),1.2^(+0.1)_(−0.1),and≥6.5 for the D48,B67,and B100 regions,*** varying gas-to-dust scale height ratios indicate that the degree of dust settling changes with *** inferred values forΛtranslate into a turbulence level of α_(turb)<3×10^(−3) in the D48 and B100 regions,which is consistent with previous upper limits set by gas line ***,turbulent motions in the B67 ring are strong with α_(turb)∼1.2×10^(−2).Due to the degeneracy betweenΛand the depth of dust surface density drops,the turbulence strength in the D86 gap region is not constrained.

关键词： protoplanetary disks radiative transfer planet formation

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

A new oxidative pathway of nitric oxide production from oximes in plants

引用

Molecular Plant 2024年第1期17卷 178-198页

作者： Pedro Lopez-Gomez Javier Buezo Marina Urra Alfonso Cornejo Raquel Esteban Jorge Fernandez de los Reyes Estibaliz Urarte Estefania Rodriguez-Dobreva Alejandro Chamizo-Ampudia Alejandro Eguaras sebastian wolf Daniel Marino Victor Martinez-Merino Jose F.Moran Institute for Multidisciplinary Research in Applied Biology(IMAB) Department of SciencesPublic University of Navarre(UPNA)Avda.de Pamplona 12331192 MutilvaSpain Institute for Advanced Materials and Mathematics(INAMAT2) Department of SciencesPublic University of Navarre(UPNA)Campus de Arosadia31006 PamplonaSpain Department of Plant Biology and Ecology University of the Basque Country(UPV/EHU)Sarriena s/nApdo.64448080 BilbaoSpain Center for Plant Molecular Biology(ZMBP) University of TubingenGeschwister-Scholl-Platz72074 TubingenGermany Institute of Natural Resources and Agrobiology of Salamanca(IRNASA) Department of Plant-Microorganism InteractionsSpanish National Research Council(CSIC)Cordel de Merinas40-5237008SalamancaSpain Department of Biochemistry Area of Molecular BiologyVeterinary FacultyUniversity of LeonCampus de Vegazanas/n.24071 LeonSpain

Nitric oxide(NO)is an essential reactive oxygen species and a signal molecule in *** several studies have proposed the occurrence of oxidative NO production,only reductive routes for NO production,such as the nitrate(NO_(3)^(-))-upper-reductase pathway,have been evidenced to date in land ***,plants grown axenically with ammonium as the sole source of nitrogen exhibit contents of nitrite and NO3−,evidencing the existence of a metabolic pathway for oxidative production of *** hypothesized that oximes,such as indole-3-acetaldoxime(IAOx),a precursor to indole-3-acetic acid,are intermediate oxidation products in NO *** detected the production of NO from IAOx and other oximes catalyzed by peroxidase(POD)enzyme using both 4-amino-5-methylamino-2′,7′-difluorescein fluorescence and *** stimulated the reaction,while superoxide dismutase inhibited ***,mouse NO synthase can also use IAOx to produce NO at a lower rate than *** provided a full mechanism for POD-dependent NO production from IAOx consistent with the experimental data and supported by density functional theory *** showed that the addition of IAOx to extracts from Medicago truncatula increased the in vitro production of NO,while in vivo supplementation of IAOx and other oximes increased the number of lateral roots,as shown for NO donors,and a more than 10-fold increase in IAOx dehydratase ***,we found that in vivo supplementation of IAOx increased NO production in Arabidopsis thaliana wild-type plants,while prx33-34 mutant plants,defective in POD33-34,had reduced *** data show that the release of NO by IAOx,as well as its auxinic effect,explain the superroot ***,our study reveals that plants produce NO utilizing diverse molecules such as oximes,POD,and flavins,which are widely distributed in the plant kingdom,thus introducing a long-awaited oxidative pathway to NO production in plants.T

关键词： ammonium oxidation auxin nitric oxide oxime peroxidase root phenotype

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

光动力治疗后的并发症

引用

美国医学会眼科杂志（中文版） 2006年第4期18卷 246-246页

作者： Ute E. K. Schnurrbusch Claudia Jochmann Wilma Einbock sebastian wolf 陈慧瑾（译）

目的：评价使用 verteporfin 行光动力疗法治疗年龄相关性黄斑变性和病理性近视继发黄斑中心凹下新生血管的并发症的发生率。

关键词：光动力疗法并发症年龄相关性黄斑变性黄斑中心凹下病理性近视新生血管发生率

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Hybrid multi-chip assembly of optical communication engines by in situ 3D nanolithography

引用

Light(Science & Applications) 2020年第1期9卷 1340-1350页

作者： Matthias Blaicher Muhammad Rodlin Billah Juned Kemal Tobias Hoose Pablo Marin-Palomo Andreas Hofmann Yasar Kutuvantavida Clemens Kieninger Philipp-Immanuel Dietrich Matthias Lauermann Stefan wolf Ute Troppenz Martin Moehrle Florian Merget sebastian Skacel Jeremy Witzens sebastian Randel wolfgang Freude Christian Koos Institute of Photonics and Quantum Electronics(IPQ) Karlsruhe Institute of Technology(KIT)Engesserstraße 576131 KarlsruheGermany Institute for Microstructure Technology(IMT) KITHermann-von-Helmholtz-Platz 176344 Eggenstein-LeopoldshafenGermany Institute for Automation and Applied Informatics(IAI) KITHermann-von-Helmholtz-Platz 176344 Eggenstein-LeopoldshafenGermany Vanguard Automation GmbH Gablonzer StraBe 1076185 KarlsruheGermany Fraunhofer Institute for Telecommunications Heinrich Hertz Institute(HHI)Einsteinufer 3710587 BerlinGermany Institute of Integrated Photonics(IPH) RWTH AachenSommerfeldstraße 18/2452074 AachenGermany

Three-dimensional(3D)nano-printing of freeform optical waveguides,also referred to as photonic wire bonding,allows for efficient coupling between photonic chips and can greatly simplify optical system *** a key advantage,the shape and the trajectory of photonic wire bonds can be adapted to the mode-field profiles and the positions of the chips,thereby offering an attractive alternative to conventional optical assembly techniques that rely on technically complex and costly high-precision ***,while the fundamental advantages of the photonic wire bonding concept have been shown in proof-of-concept experiments,it has so far been unclear whether the technique can also be leveraged for practically relevant use cases with stringent reproducibility and reliability *** this paper,we demonstrate optical communication engines that rely on photonic wire bonding for connecting arrays of silicon photonic modulators to InP lasers and single-mode *** a first experiment,we show an eight-channel transmitter offering an aggregate line rate of 448 Gbit/s by low-complexity intensity modulation.A second experiment is dedicated to a four-channel coherent transmitter,operating at a net data rate of 732.7 Gbit/s-a record for coherent silicon photonic transmitters with co-packaged *** dedicated test chips,we further demonstrate automated mass production of photonic wire bonds with insertion losses of(0.7±0.15)dB,and we show their resilience in environmental-stability tests and at high optical *** results might form the basis for simplified assembly of advanced photonic multi-chip systems that combine the distinct advantages of different integration platforms.

关键词： communication lithography bonding

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Pharmacological drug screening to inhibit uveal melanoma metastatic cells either via EGF-R, MAPK, mTOR or PI3K

引用

International Journal of Ophthalmology(English edition) 2022年第10期15卷 1569-1576页

作者： Stefan Kassumeh sebastian Arrow AndréKafka Nikolaus Luft Siegfried G.Priglinger Armin wolf Kirsten Eibl-Lindner Christian M.Wertheimer Department of Ophthalmology University HospitalLMU MunichMunich 80336Germany Department of Ophthalmology University HospitalUniversity UlmUlm 89075Germany

AIM: To screen five potential pharmacological substances specifically targeting EGF-R, MAPK, mTOR, or PI3K for their antiproliferative effects, possible impact on cell viability, as well as cell death rates on three different uveal melanoma metastasis cell lines in vitro. METHODS: Three different uveal melanoma metastasis cell lines(OMM2.5, OMM2.3, and OMM1), that originated from human hepatic and subcutaneous metastasis, were exposed to inhibitors of different targets: erlotinib(EGF-R), everolimus(mTOR), selumetinib(MAPK), trametinib(MAPK) or the alkylphosphocholine erufosine(PI3K). Cell viability was assessed with a 2,3-bis-(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide(XTT) dye reduction assay after 24 h of treatment. Antiproliferative effects were evaluated separately after a 72-hour incubation of the cells with the pharmacological substance. Subsequently, the IC_(50) was calculated. Tumor cell death was investigated using a double stain apoptosis detection assay. RESULTS: Selumetinib, trametinib, and erufosine significantly decreased cell viability of all OMM cell lines(P<0.04). In addition, selumetinib and trametinib showed a significant inhibition of cell proliferation(P<0.05). Everolimus and erlotinib solely inhibited cell proliferation at the used concentrations(P<0.05). Besides an increase of necrotic cells after erufosine treatment(P<0.001), no changes in the number of dead cells for the other substances were ***: The preliminary drug screening demonstrates five new candidates, successfully targeting the canonical MAPK/ERK and PI3K/AKT/m TOR pathways in uveal melanoma metastasis cells in vitro. Hence, these findings provide an experimental basis to explore future single or combined therapy strategies for metastatic uveal melanoma.

关键词： uveal melanoma selumetinib trametinib erufosine erlotinib

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：