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China Foundry 2009年第4期6卷 343-351页

作者： richard Larker Indexator AB Box 11 S-922 21 Vindeln Sweden

Consistent mechanical and machining properties are essential in many applications where ductile irons offer the most cost-effective way to produce structural *** the production of hydraulic rotators,dimensional tolerances are typically 20μm to obtain designated *** castings where intermediate strength and ductility is required,it is common knowledge that conventional ferritic-pearlitic ductile irons such as ISO 1083/500-7 show large hardness *** are mainly caused by the notoriously varying pearlite content,both at different locations within a part and between parts in the same or different *** rate variations due to different wall thickness and position in the molding box,as well as varying amounts of pearlite-stabilizing elements,all contribute to detrimental hardness *** obvious remedy is to avoid pearlite formation,and instead obtain the necessary mechanical properties by solution strengthening of the ferritic matrix by increasing silicon content to 3.7wt%-3.8wt%.The Swedish development in this field 1998 resulted in a national standardization as SS 140725,followed in 2004 by ISO 1083/ JS/*** AB decided 2005 to specify JS/500-10 for all new ductile iron parts and to convert all existing *** include reduction by 75%in hardness variations and increase by 30%in cutting tool life,combined with consistently better mechanical properties.

关键词： ferritic ductile irons ferritic-pearlitic ductile irons properties hydraulic rotators solutionstrengthening

The role of sphingosine-1-phosphate in bone remodeling and osteoporosis

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Bone Research 2022年第2期10卷 265-273页

作者： Justus m.Grewe Paul-richard Knapstein Antonia Donat Shan Jiang Daniel JSmit Weixin Xie Johannes Keller Department of Trauma and Orthopedic Surgery University Medical Center Hamburg-Eppendorf20246 HamburgGermany Clinic and Polyclinic for Vascular medicine University Heart Center Hamburg-Eppendorf20246 HamburgGermany Institute of Biochemistry and Signal Transduction University Medical Center Hamburg-Eppendorf20246 HamburgGermany

Osteoporosis is a systemic bone disease that affects more than 200 million people worldwide and is caused by the disruption of the equilibrium between osteoclastic bone resorption and osteoblastic bone formation. Sphingosine-1-phosphate(S1 P) is a natural,bioactive sphingolipid that has been shown to play a major role in cardiovascular and immunological pathologies by regulating biological and cellular processes, including migration, differentiation, proliferation and survival. Recent studies also suggest a central role for S1 P in bone diseases, including osteoporosis;however, the effects of S1 P, particularly in bone metabolism, remain to be further elucidated. In this review, we summarize the available literature on the role of S1 P in bone metabolism with a focus on osteoporosis. On the cellular level, S1 P acts as an osteoclast-osteoblast coupling factor to promote osteoblast proliferation and bone formation. moreover, the recruitment of osteoclast precursors to resorption sites is regulated by the interplay of S1 P gradients and S1 P receptor expression. From a clinical perspective, increasing evidence suggests that systemically elevated S1 P blood levels may serve as an independent risk factor for osteoporosis-related fractures. Taken together, S1 P signaling is a potential therapeutic target and may serve as a novel biomarker in patients with systemic bone disease.

关键词： osteoporosis metabolism expression.

Orientation of larval and juvenile horseshoe crabs Limulus polyphemus to visual cues: Effects of chemical odors

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Current Zoology 2010年第5期56卷 618-633页

作者： Julie m.mEDINA richard A.TANKERSLEY Department of Biological Sciences Florida Institute of Technology

Adult horseshoe crabs Limulus polyphemus have long served as models for the study of vision in marine arthropods. Yet, little is known about the ability of early life history stages to detect and respond to visual cues. We examined the visually directed movements of larvae and first stage juveniles to horizons containing dark visual targets of different sizes. The study tested the hypotheses that （1） larval and juvenile crabs can detect and respond to visual targets and （2） the direction of orientation varies with the presence of chemical cues associated with settlement habitats. Orientation of larval and juvenile crabs to rectangles subtending angles from 30--330~ was tested in a circular arena containing water that either lacked estuarine chemical cues （offshore water） or contained odors from aquatic vegetation or known predators. In the absence of chemical odors, larvae oriented toward and juveniles moved away from dark horizons subtending angles 〉 60~. When placed in water containing chemical odors from potential nursery habitats, including the seagrasses Halodule wrightii and Syringodium filiforme, crabs reversed their direction of orientation relative to their responses in offshore water. Odors from two known predators, the mummichug Fundulus grandis and blue crab Callinectes sapidus, had no affect on the orientation of larvae. Yet, juveniles responded to both odors by moving toward the visual target. Results support the hypothesis that the visual orientation of larval and juvenile horseshoe crabs changes upon exposure to habitat and predator cues and that the direction of the response undergoes an ontogenetic shift following metamorphosis

关键词： Orientation Visual cues Chemical odors

Chemo-dynamical modelling with Schwarzschild's method

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Research in Astronomy and Astrophysics 2018年第12期18卷 1-8页

作者： richard John Long Shude mao National Astronomical Observatories Chinese Academy of Sciences Jodrell Bank Centre for Astrophysics School of Physics and Astronomy The University of Manchester Physics Department and Tsinghua Centre for Astrophysics Tsinghua University

We extend Schwarzschild’s dynamical modelling method to model absorption line strength data as well as the more usual luminosity and kinematic *** approach draws on earlier published work by the first author with the Syer & Tremaine made-to-measure(m2m) dynamical modelling method and uses similar ideas to create a chemo-Schwarzschild *** apply our extended Schwarzschild method to the same four early type galaxies(NGC 1248, NGC 3838, NGC 4452,NGC 4551) as the chemo-m2m work, and are able to recover successfully the 2D absorption line strength for the three lines we model(Hβ, Fe5015, mg b).We believe that this is the first time Schwarzschild’s method has been used in this *** techniques developed can be applied to modelling other aspects of galaxies, for example age and metallicity data coming from stellar population modelling, and are not specific to absorption line strength data.

关键词： galaxies:abundances galaxies:formation galaxies:individual(NGC 1248,NGC 3838,NGC 4452,NGC 4551) galaxies:kinematics and dynamics galaxies:structure methods:numerical

Diverse outcomes of species interactions in an invaded annual plant community

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Journal of Plant Ecology 2017年第6期10卷 918-926页

作者： Claire E.Wainwright John m.Dwyer richard J.Hobbs margaret m.mayfield The Ecology Centre School of Biological SciencesBuilding 8The University of QueenslandSt LuciaQueensland 4072Australia Commonwealth Scientific and Industrial Research Organisation Land and WaterEcoSciences PrecinctDutton ParkQueensland 4001Australia School of Plant Biology The University of Western Australia35 Stirling HighwayCrawleyWestern Australia 6009Australia

Aims Despite acknowledgement that interactions among native and exotic species are important for determining the structure and diversity of novel communities,directed experiments using mul-tiple exotics from the same system are *** observational studies have highlighted distinct ways that exotic species interface with resident natives across invaded *** correlative nature of these studies,however,has provided few details about the mechanisms driving distinct interaction outcomes within the same *** aim was to determine how three exotic annual plant species with distinct relationships with local plant diversity impact the performance of a co-occurring native annual in the York gum-jam woodlands of Western *** We grew species in experimental communities in growth chambers at varying total planting densities to assess how interaction out-comes varied among natives and exotics across a gradient of com-petition *** measured a variety of performance responses,including survival,biomass and population-level and individual-level reproductive *** Findings Overall,the effects of interspecific versus intraspecific competi-tion on performance varied with the identity and density of exotic *** exploitative exotic grass Bromus madritensis was dominant in polyculture,whereas the diminutive grass Pentameris airoides conferred weak intraspecific competition and interspe-cific facilitation on native Waitzia *** exotic broadleaf forb,Hypochaeris glabra,suppressed growth and survival of ***,while *** had weakly negative,neutral or positive effects on all *** outcomes highlight the complexity of interac-tions impacting the diversity,stability and structure of novel plant *** few of these communities contain a single exotic species,understanding the competitive dynamics occurring in diverse novel communities is critical for their conservation and restoration.

关键词： annual plants biotic interactions competition invasion novel ecosystems

AC Impedance Behaviour of Black Diamond Films

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Journal of materials Science & Technology 2005年第6期21卷 879-882页

作者： Olivier GAUDIN richard B.JACKmAN Electronic and Electrical Engineering University College London Torrington Place London WC1E 7JE UK

The first measurement of impedance on free-standing diamond films from 0.1 Hz to 10 mHz up to 300℃ were reported. A wide range of chemical vapour deposition （CVD） materials were investigated, but here we concentrate on ‘black＇ diamond grown by microwave plasma enhanced CVD （mWPECVD）. The Cole-Cole （Z′ via Z″） plots are well fitted to a RC parallel circuit model and the equivalent resistance and capacitance for the diamond films have been estimated using the Zview curve fitting. The results show only one single semicircle response at each temperature measured. It was found that the resistance decreases from 62 mΩ at room temperature to 4 kΩ at 300℃, with an activation energy around 0.51 eV. The equivalent capacitance is maintained at the level of 100 pF up to 300℃ suggesting that the diamond grain boundaries are dominating the conduction. At 400℃, the impedance at low frequencies shows a linear tail, which can be explained that the AC polarization of diamond/Au interface occurs.

关键词： Black diamond Impedance spectroscopy Activation energy

Impact of bolus volume on small intestinal intra-luminal impedance in healthy subjects

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World Journal of Gastroenterology 2010年第17期16卷 2151-2157页

作者： Nam Q Nguyen Laura K Bryant Carly m Burgstad Robert J Fraser Daniel Sifrim richard H Holloway Department of Gastroenterology & Hepatology Royal Adelaide HospitalAdelaide 5000Australia Investigation and Procedures Unit Repatriation General HospitalDaw Park 5041Australia Department of medicine Centre for Gastroen-terological ResearchK.U.LeuvenLeuven 3000Belgium

AIm: To assess the impact of bolus volume on the characteristics of small intestinal (SI) impedance ***: Concurrent SI manometry-impedance measurements were performed on 12 healthy volunteers to assess the pattern of proximal jejunal fluid bolus movement over a 14 *** subject was given 34 boluses of normal saline (volume from 1 to 30 mL) via the feeding tube placed immediately above the proximal margin of the studied segment.A bolus-induced impedance event occurred if there was > 12% impedance drop from baseline,over ≥ 3 consecutive segments within 10 s of bolus injection.A minor or major imped-ance event was defined as a duration of impedance drop minimum volume required for a detectable SI impedance event was 2 mL.A direct linear relationship between the SI bolus volume and the occurrence of impedance events was noted until SI bolus volume reached 10 mL,a volume which always produced an impedance flow *** was a moderate correlation between the bolus volume and the duration of impedance drop (r = 0.63,P mber of propagated channels (r = 0.50,P me boluses were associated with more major impedance events (≥ 10 mL boluses = 63%,3 mL boluses = 17%,and mL boluses = 0%,P = 0.02).CONCLUSION: Bolus volume had an impact on the type and length of propagation of SI impedance events and a threshold of 2 mL is required to produce an event.

关键词： Bolus volume Health Impedance Luminal flow Small intestine

Linking uplift and mineralisation at the mount Novit Zn-Pb-Ag Deposit,Northern Australia:Evidence from geology,U-Pb geochronology and sphalerite geochemistry

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Geoscience Frontiers 2022年第2期13卷 333-350页

作者： Bradley Cave William Perkins richard Lilly Department of Earth Sciences University of AdelaideAdelaideSAAustralia Geological Survey of Queensland BrisbaneQLDAustralia

The subeconomic mount Novit Zn-Pb-Ag deposit is located approximately 20 km south of mount Isa,*** contrast to the nearby mount Isa,Hilton and George Fisher Zn-Pb-Ag deposits,mineralisation at mount Novit is situated to the west of the regional-scale mount Isa Fault and is hosted in the moondarra Siltstone as opposed to the Urquhart ***-grade(mineralisation primarily replaces pre-existing carbonate alteration and veining and consists of pyrrhotite,pyrite and sphalerite with lesser ***-grade(>10 wt.%Zn+Pb)mineralisation occurs as a matrix supported breccia dominated by sphalerite and pyrrhotite with galena,pyrite,and ***-situ U-Pb geochronology was completed on apatite and two textural varieties of ***-grained(m)subhedral to anhedral monazite is located within highly foliated biotite alteration directly adjacent Zn-Pb-Ag mineralisation and yields a mean weighted^(207)Pb/^(206)Pb age of 1527±18 ma(mSWD=1.06).This age is consistent with the formation of highly foliated biotite alteration during D;deformation of the Isan *** from the same fabric yields a lower intercept age of1443±29 ma(mSWD=1.30).Consistent with previous studies,this age is interpreted to represent the age of a major thrusting event along the mount Isa Fault that resulted in the cooling of the mount Novit area below~375℃.Coarse-grained monazite is coeval with Zn-Pb-Ag mineralisation and yields a mean weighted^(207)Pb/^(206)Pb age of 1457±11 ma(mSWD=0.28).Sphalerite from mount Novit has low concentrations(m)of Ge and Ga and a relatively high concentration of In(5 to>10 ppm),possibly reflecting the leaching of the metals from an underlying basement *** GGImFis geothermometer(Frenzel et al.,2016)produced a mean formation temperature of 345±52℃.The timing and temperature of Zn-Pb-Ag mineralisation is consistent with the age and cooling temperature of apatite presented in this *** on these correlations,we

关键词： mount Isa mount Novit Zn-Pb-Ag mineralisation monazite Apatite Geochronology

Assessing the impact of conceptual mineral systems uncertainty on prospectivity predictions

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Geoscience Frontiers 2022年第6期13卷 182-207页

作者： mark D Lindsay Agnieszka m.Piechocka mark W Jessell richard Scalzo Jeremie Giraud Guillaume Pirot Edward Cripps Commonwealth Scientific and Industrial Research Organisation Mineral Resources Australian Resources Research CentreWA 6151Australia mineral Exploration Cooperative Research Centre Centre for Exploration TargetingSchool of Earth SciencesThe University of Western AustraliaPerthWA 6009Australia ARC Centre for Data Analytics for Resources and Environments(DARE) Perth and SydneyAustralia University of Sydney School of Mathematics and StatisticsSydneyAustralia Universitéde Lorraine GeoRessourcesCNRS54000 NancyFrance The University of Western Australia Department of Mathematics and StatisticsPerthAustralia

The past two decades have seen a rapid adoption of artificial intelligence methods applied to mineral exploration. more recently, the easier acquisition of some types of data has inspired a broad literature that has examined many machine learning and modelling techniques that combine exploration criteria,or ’features’, to generate predictions for mineral prospectivity. Central to the design of prospectivity models is a ’mineral system’, a conceptual model describing the key geological elements that control the timing and location of economic mineralisation. The mineral systems model defines what constitutes a training set, which features represent geological evidence of mineralisation, how features are engineered and what modelling methods are used. mineral systems are knowledge-driven conceptual models, thus all parameter choices are subject to human biases and opinion so alternative models are ***, the effect of alternative mineral systems models on prospectivity is rarely compared despite the potential to heavily influence final predictions. In this study, we focus on the effect of conceptual uncertainty on Fe ore prospectivity models in the Hamersley region, Western Australia. Four important considerations are tested.(1) Five different supergene and hypogene conceptual mineral systems models guide the inputs for five forest-based classification prospectivity models model.(2) To represent conceptual uncertainty, the predictions are then combined for prospectivity model comparison.(3)Representation of three-dimensional objects as two-dimensional features are tested to address commonly ignored thickness of geological units.(4) The training dataset is composed of known economic mineralisation sites(deposits) as ’positive’ examples, and exploration drilling data providing ’negative’sampling locations. Each of the spatial predictions are assessed using independent performance metrics common to AI-based classification methods and subjected to geological pl

关键词： Uncertainty modelling Prospectivity Economic geology Geological plausibility Forest-based classification

Luminescence of Er^(3+) in Oxyfluoride Transparent Glass-Ceramics

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Journal of Rare Earths 2006年第6期24卷 699-705页

作者： Akira Ueda Steven H morgan richard mu Department of Physics Fisk University NashvilleTN 37208 USA

Erbium doped silicate, germanate, and tellurium-germanate oxyfluoride glasses were prepared in a bulk form. Through appropriate heat treatment of the as-prepared glasses, transparent glass-ceramics （TGCs） were obtained with the formation of β-PbF2：Er^3＋ nanocrystals in the glass matrix were confirmed by X-ray ***-defined diffraction peaks were observed in the samples after heat-treatment. The average crystal diameter of these precipitated crystals from full-width at half-maximum （FWHm） of the diffraction peak was estimated to be between 8 and 13 nm. Optical absorption, photoluminescence, and upconversion luminescence were measured on as-prepared glass and glass-ceramics. Luminescence spectra in the TGC samples revealed well-resolved, sharp stark-splitting peaks, which indicates that a majority of Er^3＋ ions has been incorporated into the crystalline phase of the nanocrystals. The intensity of the visible and near infrared luminescence mostly increases in TSG compared to that in the as-prepared glass. In 1.53 μm absorption and emission bands, the maximum absorption peak is blue-shifted from 1531 to 1507 nm, whereas the maximum emission peak is redshifted from 1535 to 1543 nm in TGC, as compared with that in glass. The bandwidth at half-maximum （BWHm） of the emission band is significantly broader in TGC than in glass, which is beneficial to the erbium-doped fiber amplifier （EDFA）. Upconversion luminescence was measured using 800 nm near-infrared light excitation. Drastically increased upconversion 1 was observed from the TGC as compared to that from their corresponding as-prepared glasses. In addition to a strong green emission centered at 545 nm because of ^4S3/2→^4I15/2 transition and a weaker red emission centered at 662 nm because of ^4F9/2→^4I15/2 transition, generally seen from the Er^3＋ doped glasses, two violet emissions centered at 410 nm because of ^2H9/2→^4I15/2 transition and centered at 379 nm because of ^4G11/2→^4I15/2 transition were also o

关键词： luminescence transparent glass-ceramics rare earths