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Sex ratio variation and sex determination in the mallee dragon Ctenophorus fordi

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Integrative Zoology 2008年第3期3卷 157-165页

作者： tobias ULLER Gaetano ODIERNA Mats OLSSON School of Biological Sciences University of WollongongWollongongNew South WalesAustralia Department of Structural and Functional Biology University of Naples Federico IINaplesItaly

Recent evidence suggests that many Australian agamids show temperature-dependent sex determination(TSD)with variation in sex determining mechanisms among closely related ***,as shown in other vertebrates,sex ratios can also be influenced by genetic or phenotypic differences among females in their propensity to produce sons or daughters,and these influences might confound any thermal effects of incubation per *** address these issues,we investigated the determinants of sex ratios in the mallee dragon Ctenophorus fordi,together with a detailed analysis of *** was no detectable variation in sex ratios arising from variation among females,clutches or incubation temperatures,which might indicate genetic sex determination for this ***,there was no evidence of cytologically distinct sex chromosomes using standard banding *** sex ratio pattern in *** strongly contrasts with the results for the congener Ctenophorus pictus,where sex ratios show variation among ***,Australian agamids offer promising opportunities to address fundamental issues in sex ratio biology.

关键词： genetic-dependent sex determination lizard sex ratio sex allocation temperature-dependent sex determination.

Chirality-Induced Giant Unidirectional Magnetoresistance in Twisted Bilayer Graphene

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The Innovation 2021年第1期2卷 56-62页

作者： Yizhou Liu tobias Holder Binghai Yan Department of Condensed Matter Physics Weizmann Institute of ScienceRehovot 76100Israel

Twisted bilayer graphene(TBG)exhibits fascinating correlation-driven phenomena like the superconductivity and Mott insulating state,with flat bands and a chiral lattice *** find by quantum-transport calculations that the chirality leads to a giant unidirectional magnetoresistance(UMR)in TBG,where the unidirectionality refers to the resistance change under the reversal of the direction of current or magnetic *** point out that flat bands significantly enhance this *** UMR increases quickly upon reducing the twist angle,and reaches about 20%for an angle of 1.5in a 10 T in-plane magnetic *** propose the band structure topology(asymmetry),which leads to a direction-sensitive mean free path,as a useful way to anticipate the UMR *** UMR provides a probe for chirality and band flatness in the twisted bilayers.

关键词： twisted bilayer graphene unidirectional magnetoresistance nonreciprocal transport chirality flat bands topology nonlinear phenomena

Extension of Flow Behaviour and Damage Models for Cast Iron Alloys with Strain Rate Effect

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Chinese Journal of Mechanical Engineering 2024年第3期37卷 297-310页

作者： Chuang Liu Dongzhi Sun Xianfeng Zhang Florence Andrieux tobias Gersterc School of Mechanical Engineering Nanjing University of Science and TechnologyNanjing 210094China Fraunhofer Institute for Mechanics of Materials(IWM) 79108 FreiburgGermany Fraunhofer Institute for High Speed Dynamics Ernst-Mach-Institute(EMI)79104 FreiburgGermany

Cast iron alloys with low production cost and quite good mechanical properties are widely used in the automotive *** study the mechanical behavior of a typical ductile cast iron(GJS-450)with nodular graphite,uni-axial quasi-static and dynamic tensile tests at strain rates of 10^(-4),1,10,100,and 250 s^(-1)were carried *** order to investigate the influence of stress state on the deformation and fracture parameters,specimens with various geometries were used in the *** strain curves and fracture strains of the GJS-450 alloy in the strain rate range of 10^(-4)to 250 s^(-1)were obtained.A strain rate-dependent plastic flow model was proposed to describe the mechanical behavior in the corresponding strain-rate *** available damage model was extended to take the strain rate into account and calibrated based on the analysis of local fracture *** with the proposed plastic flow model and the damage model were conducted to observe the deformation and fracture *** results show that the strain rate has obviously nonlinear effects on the yield stress and fracture strain of GJS-450 *** predictions with the proposed plastic flow and damage models at various strain rates agree well with the experimental results,which illustrates that the rate-dependent plastic flow and damage models can be used to describe the mechanical behavior of cast iron alloys at elevated strain *** proposed plastic flow and damage models can be used to describe the deformation and fracture analysis of materials with similar properties.

关键词： Dynamic behavior of materials Strain rate dependency Damage model Voce model Cast iron

Inkjet printing of epitaxially connected nanocrystal superlattices

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Nano Research 2022年第5期15卷 4536-4543页

作者： Daniel M.Balazs NDeniz Erkan Michelle Quien tobias Hanrath School of Chemical and Biomolecular Engineering Cornell UniversityIthacaNYUSA Institute of Science and Technology Austria Am Campus 1Klosterneuburg 3400Austria

Access to a blossoming library of colloidal nanomaterials provides building blocks for complex assembled *** journey to bring these prospects to fruition stands to benefit from the application of advanced processing *** connected nanocrystal(or quantum dot)superlattices present a captivating model system for mesocrystals with intriguing emergent *** conventional processing approach to creating these materials involves assembling and attaching the constituent nanocrystals at the interface between two immiscible *** small liquid volumes of the colloidal nanocrystal solution involves several complexities arising from the concurrent spreading,evaporation,assembly,and *** ability of inkjet printers to deliver small(typically picoliter)liquid volumes with precise positioning is attractive to advance fundamental insights into the processing science,and thereby potentially enable new routes to incorporate the epitaxially connected superlattices into technology *** this study,we identified the processing window of opportunity,including nanocrystal ink formulation and printing approach to enable delivery of colloidal nanocrystals from an inkjet nozzle onto the surface of a sessile droplet of the immiscible *** demonstrate how inkjet printing can be scaled-down to enable the fabrication of epitaxially connected superlattices on patterned sub-millimeter *** anticipate that insights from this work will spur on future advances to enable more mechanistic insights into the assembly processes and new avenues to create high-fidelity superlattices.

关键词： interfacial assembly colloidal nanocrystal superlattice inkjet printing

Current medical management of endocrine-related male infertility

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Asian Journal of Andrology 2016年第3期18卷 357-363,I0007页

作者： Joshua D Ring Aye A Lwin tobias S Kohler Division of Urology Department of Surgery Southern Illinois University Springfield IL 62794 USA.

Male factor contributes to 50%-60% of overall infertility but is solely responsible in only 20% of couples. Although most male factor infertility is ascertained from an abnormal semen analysis, other male factors can be contributory especially if the sample returns normal. Male infertility can be due to identifiable hormonal or anatomical etiologies that may be reversible or irreversible. This manuscript will highlight existing guidelines and our recommendations for hormone evaluation for male infertility and empiric therapies including multivitamins, estrogen receptor modulators （clomiphene）, estrogen conversion blockers （anastrozole）, and hormone replacement.

关键词： anastrazole clomid human chorionic gonadotropin male infertility sex hormone-binding globulin

Plasma-assisted molecular beam epitaxy of ZnO on in-situ grown GaN/4H-SiC buffer layers

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Frontiers of Materials Science 2015年第2期9卷 185-191页

作者： David ADOLPH tobias TINGBERG Thorvald ANDERSSON Tommy IVE Department of Microtechnology and Nanoscience (MC2) Chalmers University of Technology GSteborg Sweden

Plasma-assisted molecular beam epitaxy （MBE） was used to grow ZnO （0001） layers on GaN（0001）/4H-SiC buffer layers deposited in the same growth chamber equipped with both N- and O-plasma sources. The GaN buffer layers were grown immediately before initiating the growth of ZnO. Using a substrate temperature of 440℃- 445℃ and an 02 flow rate of 2.0-2.5 sccm, we obtained ZnO layers with smooth surfaces having a root-mean-square roughness of 0.3 nm and a peak-to-valley distance of 3 nm shown by AFM. The FWHM for X-ray rocking curves recorded across the ZnO（0002） and ZnO（1015） reflections were 200 and 950 arcsec, respectively. These values showed that the mosaicity （tilt and twist） of the ZnO film was comparable to corresponding values of the underlying GaN buffer. It was found that a substrate temperature 〉 450℃ and a high Zn-flux always resulted in a rough ZnO surface morphology. Reciprocal space maps showed that the in-plane relaxation of the GaN and ZnO layers was 82.3% and 73.0%, respectively and the relaxation occurred abruptly during the growth. Room-temperature Hall-effect measurements showed that the layers were intrinsically n-type with an electron concentration of 10^19 cm-3 and a Hall mobility of 50 cm2.V-1 .s-1.

关键词： ZnO molecular beam epitaxy (MBE) epitaxy

Process Characterization of the Transesterification of Rapeseed Oil to Biodiesel Using Design of Experiments and Infrared Spectroscopy

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Journal of Renewable Materials 2023年第4期11卷 1643-1660页

作者： tobias Drieschner Andreas Kandelbauer Bernd Hitzmann Karsten Rebner Lehr-und Forschungszentrum Process Analysis and Technology(PA&T)der Hochschule Reutlingen Reutlingen72762Germany Department of Process Analytics and Cereal Science Institute of Food Science and BiotechnologyUniversität HohenheimStuttgart70599Germany

For optimization of production processes and product quality,often knowledge of the factors influencing the process outcome is ***,process analytical technology(PAT)that allows deeper insight into the process and results in a mathematical description of the process behavior as a simple function based on the most important process factors can help to achieve higher production efficiency and *** present study aims at characterizing a well-known industrial process,the transesterification reaction of rapeseed oil with methanol to produce fatty acid methyl esters(FAME)for usage as biodiesel in a continuous micro reactor *** this end,a design of experiment approach is applied,where the effects of two process factors,the molar ratio and the total flow rate of the reactants,are *** optimized process target response is the FAME mass fraction in the purified nonpolar phase of the product as a measure of reaction *** quantification is performed using attenuated total reflection infrared spectroscopy in combination with partial least squares *** data retrieved during the conduction of the DoE experimental plan were used for statistical analysis.A non-linear model indicating a synergistic interaction between the studied factors describes the reactor behavior with a high coefficient of determination(R^(2))of ***,we applied a PAT approach to generate further insight into this established industrial process.

关键词： Process analytical technology transesterification design of experiment attenuated total reflection infrared spectroscopy partial least square regression

Determination of slug permeability factor for pressure drop prediction of slug flow pneumatic conveying

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Particuology 2008年第5期6卷 307-315页

作者： Kenneth C.Williams Mark G.Jones tobias Krull Centre for Bulk Solids and Particulate Technology The University of NewcastleCallaghanNSW 2308Australia

Current models for pressure drop prediction of slug flow pneumatic conveying in a horizontal pipeline system assume some type of steady state conditions for prediction, which limits their capability for increased predictive accuracy relative to experimental data. This is partly because of the nature of slug flow pneumatic conveying system, which, as a dynamic system, never becomes stable. By utilising conservation of mass （airflow）, a dynamic pressure analysis model is proposed on the basis of the derivative of the upstream pressure behaviour. The rate of air permeation through slug, one of the important factors in the conservation model, is expressed as a function of a slug permeability factor. Other factors such as slug velocity, slug length and the fraction of stationary layer were also considered. Several test materials were conveyed in single-slug tests to verify the proposed pressure drop model, showing good agreement between the model and experimental results.

关键词： Slug flow pneumatic conveying Pressure drop Air mass conversation Slug permeability factor

Do microsporidia function as ＂biological weapon＂ for Harmonia axyridis under natural conditions？

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Insect Science 2015年第3期22卷 353-359页

作者： tobias Gegner Oliver Otti Simon Tragust Heike Feldhaar Animal Population Ecology Department of Animal Ecology I Bayreuth Center of Ecology and Environmental Research (BayCEER) University of Bayreuth D-95440 Bayreuth Germany

Invasive alien species, such as the multicoloured Asian ladybird Harmonia axyridis, are often regarded as major drivers ofbiodiversity loss. Therefore understanding which characteristics or mechanisms contribute to their invasive success is important. Here the role of symbiotic microsporidia in the hemolymph of H. axyridis was investigated in the context of intraguild predation between wild-caught H. axyridis and the native ladybird species Coccinella septempunctata. The microsporidia were recently discussed to contribute to the unpalatability of Harmonia for other coccinellids during intraguild predation and to function as ＂biological weapons＂. In the present study, visual detection of microsporidia in hemolymph samples revealed that 73.5 % of H. axyridis were infected. Intraguild predation experiments between larvae of the two species showed a significant competitive advantage for H. axyridis, even against larger larvae of C. septempunctata. Adult C. septempunctata always killed and fed on H. axyridis larvae. However only 11.4 % （4 of 47） of C. septempunctata that fed on infected H. axyridis died within 4 months. In contrast to previous studies this suggests that microsporidia or harmonine, the chemical defense compound of H. axyridis, do not lead to death of C. septempunctata preying on larvae ofH. axyridis. Instead our results support the idea that competitive advantage during intraguild predation greatly facilitates the success of H. axyridis and that this may help this highly invasive species to outcompete native species. The impact of microsporidia on Harmonia itself as well as on interspecific interactions require further studies.

关键词： defensive symbiont endosymbiont Harmonia axyridis invasive species microsporidia