检索结果-南通市图书馆

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

A CARBON CLOUD WITH PLATINUM LINING

在线全文

学校读者我要写书评

暂无评论

Journal of Green Building 2010年第3期5卷 69-82页

作者： richard Stott Steelbone Design Company

Picture *** a freezing December day,a few days before Christmas,2008 an electrical fire started in the basement utility *** burn damage was so severe at the origin site that the exact cause could not be determined,but the theory is that a transfer switch connected to an emergency power generator started the fire when an auto test series was *** fire quickly spread to the ceiling of the basement utility room,which was not fire rated,and burned the floor out of the kitchen above,at the center of the two-story *** a very short time,the kitchen collapsed into the *** fire began shortly after the five family members left for work and school and was discovered by a worker who arrived to complete a bathroom *** black smoke poured through every vent to the *** the time firefighters gained control of the blaze,the 3,000-sq-ft house and everything in it was *** this image conjures a big black carbon cloud for you,imagine what the family was going *** they owned was burned or covered with black soot and *** was a devastating blow to a smart young family going about their daily *** was the epitome of a dark cloud,and a silver lining seemed only like a *** the same time,a group of local tradesmen called the Hamptons Green Alliance(HGA),who organized a few months earlier,were busy soliciting local *** the AIA Peconic,the HGA sent an e-mail blast to all members in order to find a project they could initiate in order to exercise their old and new sustainable building *** goals were to apply their cumulative knowledge and expertise in sustainable practices and integrate them into a sum greater than the *** individual company had experience,but never before had they consciously collaborated on a design that integrated all their systems at *** would share the benefit and help the HGA raise the bar on sustainable building so they could offer experience,expertise,

关键词： LEED for Homes LEED Platinum solar thermal evacuated tubes geo-thermal USGBC Solatube high/low density spray foam insulation rainwater harvesting photovoltaic carbon neutral wind turbine Energy Star

The NGC 7742 star cluster luminosity function： a population analysis revisited

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

Research in Astronomy and Astrophysics 2018年第2期18卷 1-6页

作者： richard de Grijs Chao Ma Kavli Institute for Astronomy & Astrophysics Peking University Beijing 100871 China Department of Astronomy Peking University Beijing 100871 China International Space Science Institute-Beijing Beijing 100190 China

We re-examine the properties of the star cluster population in the circumnuclear starburst ring in the face-on spiral galaxy NGC 7742, whose young cluster mass function has been reported to exhibit significant deviations from the canonical power law. We base our reassessment on the clusters＇ luminosi- ties （an observational quantity） rather than their masses （a derived quantity）, and confirm conclusively that the galaxy＇s starburst-ring clusters--and particularly the youngest subsample, log（t yr-1） ≤7.2- show evidence of a turnover in the cluster luminosity function well above the 90% completeness limit adopted to ensure the reliability of our results. This confirmation emphasizes the unique conundrum posed by this unusual cluster population.

关键词： globular clusters: general - galaxies: evolution - galaxies: individual (NGC 7742)--galaxies: star clusters: general -- galaxies: star formation

A critical review of the fatigue life prediction of asphalt mixtures and pavements

在线全文

学校读者我要写书评

暂无评论

Journal of Traffic and Transportation Engineering(English Edition) 2022年第5期9卷 808-835页

作者： Nithin Sudarsanan Youngsoo richard Kim Department of Civil Constructionand Environmental EngineeringNorth Carolina State UniversityRaleighNC 27695USA

New pavement construction techniques and the increased use of recycled materials have led to unexpected and premature pavement failure in recent *** pavement’s exposure to daily and seasonal extreme temperature and repeated vehicular loads accumulate *** cracking occurs once the cumulative damage surpasses the material’s cracking *** crack is the most common pavement cracking *** the past four decades,researchers have carried out numerous experiments and analyses to understand pavement *** paper aims to provide an overview of fatigue cracking and discuss various fatigue test methods for characterizing asphalt concrete *** article also discusses the most common phenomenological and mechanistic models for predicting the fatigue life of asphalt concrete pavements based on different fatigue test *** paper details the implementation of the commonly used numerical models found in numerical simulation software and their prediction ability for the fatigue life of a pavement *** major flaws in current evaluation methods are the sensitivity of experimental results and the lack of reliability of some predictive *** asphalt material characterization is the ongoing practice for determining the most appropriate performance evaluation ***,proceeding with future research objectives is unrealistic until the accuracy of the tests and reliability of the predictions can be verified against actual field *** critical review of the fatigue life predictions of asphalt mixtures and pavements should help to refine or redefine the right course of action for future research.

关键词： Fatigue cracking Failure criteria Fracture mechanics Simplified viscoelastic continuum damage(S-VECD)model Mechanistic-Empirical Pavement Design Guideline(MEPDG)

A composite particle swarm algorithm for global optimization of multimodal functions

在线全文

学校读者我要写书评

暂无评论

Journal of Central South University 2014年第5期21卷 1871-1880页

作者：谭冠政鲍琨 richard Maina Rimiru School of Information Science and Engineering Central South University

During the last decade, many variants of the original particle swarm optimization （PSO） algorithm have been proposed for global numerical optimization, hut they usually face many challenges such as low solution quality and slow convergence speed on multimodal function optimization. A composite particle swarm optimization （CPSO） for solving these difficulties is presented, in which a novel learning strategy plus an assisted search mechanism framework is used. Instead of simple learning strategy of the original PSO, the proposed CPSO combines one particle＇s historical best information and the global best information into one learning exemplar to guide the particle movement. The proposed learning strategy can reserve the original search information and lead to faster convergence speed. The proposed assisted search mechanism is designed to look for the global optimum. Search direction of particles can be greatly changed by this mechanism so that the algorithm has a large chance to escape from local optima. In order to make the assisted search mechanism more efficient and the algorithm more reliable, the executive probability of the assisted search mechanism is adjusted by the feedback of the improvement degree of optimal value after each iteration. According to the result of numerical experiments on multimodal benchmark functions such as Schwefel, Rastrigin, Ackley and Griewank both with and without coordinate rotation, the proposed CPSO offers faster convergence speed, higher quality solution and stronger robustness than other variants of PSO.

关键词： particle swarm algorithm global numerical optimization novel learning strategy assisted search mechanism feedbackprobability regulation

Chemo-dynamical modelling with Schwarzschild's method

在线全文

学校读者我要写书评

暂无评论

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

Quantifying Likelihood in Digital Forensic Investigations

在线全文

学校读者我要写书评

暂无评论

Journal of Harbin Institute of Technology(New Series) 2014年第6期21卷 1-4页

作者： richard E Overill Department of Informatics King's College LondonLondon WC2R 2LSUnited Kingdom

While the conventional forensic scientists routinely validate and express the results of their investigations quantitatively using statistical measures from probability theory,digital forensics examiners rarely if ever do *** this paper,we review some of the quantitative tools and techniques which are available for use in digital forensic investigations,including Bayesian networks,complexity theory,information theory and probability theory,and indicate how they may be used to obtain likelihood ratios or odds ratios for the relative plausibility of alternative explanations for the creation of the recovered digital *** potential benefits of such quantitative measures for modern digital forensics are also outlined.

关键词： likelihood ratio odds ratio Bayesian network power law statistics,probability theory complexity theory information theory

Cell transplantation to replace retinal ganglion cells faces challenges-the Switchboard Dilemma

在线全文

学校读者我要写书评

暂无评论

Neural Regeneration Research 2021年第6期16卷 1138-1143页

作者： Yuan Liu richard K.Lee Bascom Palmer Eye Institute University of Miami Miller School of MedicineMiamiFLUSA

The mammalian retina displays incomplete intrinsic regenerative capacities;therefore,retina degeneration is a major cause of irreversible blindness such as glaucoma,agerelated macular degeneration and diabetic *** diseases lead to the loss of retinal cells and serious vision loss in the late *** cell transplantation is a great promising novel treatment for these incurable retinal degenerative diseases and represents an exciting area of regenerative *** suitable stem cell sources for transplantation including human embryonic stem cells,induced pluripotent stem cells and adult stem cells have been identified as promising target ***,the retina is an elegant neuronal complex composed of various types of cells with different *** replacement of these different types of cells by transplantation should be addressed *** far,retinal pigment epithelium transplantation has achieved the most advanced stage of clinical trials,while transplantation of retinal neurons such as retinal ganglion cells and photoreceptors has been mostly studied in pre-clinical animal *** this review,we opine on the key problems that need to be addressed before stem cells transplantation,especially for replacing injured retinal ganglion cells,may be used practically for treatment.A key problem we have called the Switchboard Dilemma is a major block to have functional retinal ganglion cell *** use the public switchboard telephone network as an example to illustrate different difficulties for replacing damaged components in the retina that allow for visual *** ganglion cell transplantation is confronted by significant hurdles,because retinal ganglion cells receive signals from different interneurons,integrate and send signals to the correct targets of the visual system,which functions similar to the switchboard in a telephone network-therefore the Switchboard Dilemma.

关键词： cell transplantation optic nerve regeneration photoreceptors retina degeneration retinal ganglion cells stem cells

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

在线全文

学校读者我要写书评

暂无评论

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(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(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

Dynamic Scaling of the Generalized Complementary Relationship Improves Long-term Tendency Estimates in Land Evaporation

在线全文

学校读者我要写书评

暂无评论

Advances in Atmospheric Sciences 2020年第9期37卷 975-986页

作者： Jozsef SZILAGYI richard CRAGO Ning MA Department of Hydraulic and Water Resources Engineering Budapest University of Technology H-1111Budapest Hungary Conservation and Survey Division School of Natural ResourcesUniversity of Nebraska-LincolnLincolnNebraska 68583USA Department of Civil and Environmental Engineering Bucknell UniversityLewisburgPennsylvania 17837USA Key Laboratory of Water Cycle and Related Land Surface Processes Institute of Geographic Sciences and Natural Resources ResearchChinese Academy of SciencesBeijing 100101China

Most large-scale evapotranspiration(ET)estimation methods require detailed information of land use,land cover,and/or soil type on top of various atmospheric *** complementary relationship of evaporation(CR)takes advantage of the inherent dynamic feedback mechanisms found in the soil−vegetation−atmosphere interface for its estimation of ET rates without the need of such biogeophysical *** estimates over the conterminous United States by a new,globally calibrated,static scaling(GCR-stat)of the generalized complementary relationship(GCR)of evaporation were compared to similar estimates of an existing,calibration-free version(GCR-dyn)of the GCR that employs a temporally varying dynamic *** annual water balances of 327 medium and 18 large watersheds served as ground-truth ET *** long-term monthly mean forcing,GCR-stat(also utilizing precipitation measurements)outperforms GCR-dyn as the latter cannot fully take advantage of its dynamic scaling with such data of reduced temporal ***,in a continuous monthly simulation,GCR-dyn is on a par with GCR-stat,and especially excels in reproducing long-term tendencies in annual catchment ET rates even though it does not require precipitation *** same GCR-dyn estimates were also compared to similar estimates of eight other popular ET products and they generally outperform all of *** this reason,a dynamic scaling of the GCR is recommended over a static one for modeling long-term behavior of terrestrial ET.

关键词： land−atmosphere interactions land evaporation evapotranspiration complementary relationship of evaporation