检索结果-南通市图书馆

Acta Metallurgica Sinica(English Letters) 2022年第1期35卷 49-66页

作者： Guang Zeng Shiqian Liu Qinfen Gu Zebang Zheng Hideyuki Yasuda stuart D.McDonald Kazuhiro Nogita School of Materials Science and Engineering Central South UniversityChangsha 410083China Nihon Superior Centre for the Manufacture of Electronic Materials(NS CMEM) School of Mechanical and Mining EngineeringThe University of QueenslandBrisbaneQLD 4072Australia Graduate School Shenzhen Technology UniversityShenzhen 515118China Australian Synchrotron ANSTO.800 Blackburn RdClaytonVIC 3168Australia State Key Laboratory of Solidification Processing School of Materials Science and EngineeringNorthwestern Polytechnical UniversityXi’an 710072China Department of Materials Science and Engineering Kyoto UniversitySakyo‑kuKyoto 606‑8501Japan

It is widely accepted that further development of Pb-free solder alloys for improved processing and in-service properties of next-generation electronics,can be accelerated through a fundamental understanding of phase transformation and microstructure control in Pb-free solder *** characterization techniques including synchrotron radiation provide a comprehensive toolset to measure the composition,crystallography,morphology,and properties of the major components of solder *** research using such techniques is reviewed in detail including the characterization of the eff ects of microalloy additions on the microstructure and properties of Pb-free solder joints,especially those on the intermetallic *** discoveries outlined are of scientific and industrial relevance and have implications for new solder alloy composition design and the reliability of lead-free solder joints.

关键词： Cu_(6)Sn_(5)intermetallic Synchrotron radiation Solidification Phase transformation

“My ADHD Hellbrain”: A Twitter Data Science Perspective on a Behavioural Disorder

在线全文

学校读者我要写书评

暂无评论

Journal of Data and Information Science 2021年第1期6卷 13-34页

作者： Mike Thelwall Meiko Makita Amalia Mas-Bleda Emma stuart Statistical Cybermetrics Research Group University of WolverhamptonUK

Purpose: Attention deficit hyperactivity disorder(ADHD) is a common behavioural condition. This article introduces a new data science method, word association thematic analysis, to investigate whether ADHD tweets can give insights into patient concerns and online communication needs. Design/methodology/approach: Tweets matching "my ADHD"(n=58,893) and 99 other conditions(n=1,341,442) were gathered and two thematic analyses conducted. Analysis 1: A standard thematic analysis of ADHD-related tweets. Analysis 2: A word association thematic analysis of themes unique to ***: The themes that emerged from the two analyses included people ascribing their brains agency to explain and justify their symptoms and using the concept of neurodivergence for a positive self-image. Research limitations: This is a single case study and the results may differ for other *** implications: Health professionals should be sensitive to patients' needs to understand their behaviour, find ways to justify and explain it to others and to be positive about their ***/value: Word association thematic analysis can give new insights into the(self-reported) patient perspective.

关键词： ADHD Word association thematic analysis Social behaviour Social web Twitter

Search-Based Software Test Data Generation for Path Coverage Based on a Feedback-Directed Mechanism

在线全文

学校读者我要写书评

暂无评论

Complex System Modeling and Simulation 2023年第1期3卷 12-31页

作者： stuart Dereck Semujju Han Huang Fangqing Liu Yi Xiang Zhifeng Hao School of Software Engineering South China University of TechnologyGuangzhou 510006China College of Science Shantou UniversityShantou 515063China

Automatically generating test cases by evolutionary algorithms to satisfy the path coverage criterion has attracted much research attention in software *** the context of generating test cases to cover many target paths,the efficiency of existing methods needs to be further improved when infeasible or difficult paths exist in the program under *** is because a significant amount of the search budget(i.e.,time allocated for the search to run)is consumed when computing fitness evaluations of individuals on infeasible or difficult *** this work,we present a feedback-directed mechanism that temporarily removes groups of paths from the target paths when no improvement is observed for these paths in subsequent *** fulfill this task,our strategy first organizes paths into ***,in each generation,the objective scores of each individual for all paths in each group are summed *** each group,the lowest value of the summed up objective scores among all individuals is assigned as the best aggregated score for a group.A group is removed when no improvement is observed in its best aggregated score over the last two *** experimental results show that the proposed approach can significantly improve path coverage rates for programs under test with infeasible or difficult paths in case of a limited search *** particular,the feedback-directed mechanism reduces wasting the search budget on infeasible paths or on difficult target paths that require many fitness evaluations before getting an improvement.

关键词： automated test case generation software testing path coverage many-objective optimization

Developing Extensible Lattice-Boltzmann Simulators for General-Purpose Graphics-Processing Units

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

Communications in Computational Physics 2013年第3期13卷 867-879页

作者： stuart D.C.Walsh Martin O.Saar Lawrence Livermore National Laboratory LivermoreCaliforniaUSA Department of Earth Sciences University of MinnesotaMinneapolisMinnesotaUSA

Lattice-Boltzmann methods are versatile numerical modeling techniques capable of reproducing a wide variety of fluid-mechanical *** methods are well suited to parallel implementation,particularly on the single-instruction multiple data(SIMD)parallel processing environments found in computer graphics processing units(GPUs).Although recent programming tools dramatically improve the ease with which GPUbased applications can be written,the programming environment still lacks the flexibility available to more traditional CPU *** particular,it may be difficult to develop modular and extensible programs that require variable on-device functionality with current GPU *** paper describes a process of automatic code generation that overcomes these difficulties for lattice-Boltzmann *** details the development of GPU-based modules for an extensible lattice-Boltzmann simulation *** performance of the automatically generated code is compared to equivalent purpose written codes for both single-phase,multiphase,and multicomponent *** flexibility of the new method is demonstrated by simulating a rising,dissolving droplet moving through a porous medium with user generated lattice-Boltzmann models and subroutines.

关键词： Lattice-Boltzmann methods graphics processing units computational fluid dynamics

Two species of microcracks

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

Applied Geophysics 2014年第1期11卷 1-8,115页

作者： stuart Crampin 高原 British Geological Survey School of GeoSciences University of Edinburgh Institute of Earthquake Science China Earthquake Administration

We identify two interrelated but independent species of microcracks with different origins and different distributions. One species is the classic high-stress microcracks identified in laboratory stress-cells associated with acoustic emissions as microcracks open with increasing stress. The other species is the low-stress distributions of closely-spaced stress-aligned fluid-saturated microcracks that observations of shear-wave splitting(SWS) demonstrate pervade almost all in situ rocks in the upper crust, the lower crust, and the uppermost 400 km of the mantle. On some occasions these two sets of microcracks may be interrelated and similar(hence ‘species') but they typically have fundamentally-different properties, different distributions, and different implications. The importance for hydrocarbon exploration and recovery is that SWS in hydrocarbon reservoirs monitors crack alignments and preferred directions of fluid-flow. The importance for earthquake seismology is that SWS above small earthquakes monitors the effects of increasing stress on the pervasive low-stress microcrack distributions so that stress-accumulation before, possibly distant, earthquakes can be recognised and impending earthquakes stress-forecast.

关键词： crack-induced anisotropy fluid-saturate microcracks shearwave splitting stressforecasting earthquakes two species of microcracks

Concept development and testing of the UK’s first hydrogenhybrid train(HydroFLEX)

在线全文

学校读者我要写书评

暂无评论

Railway Engineering Science 2021年第3期29卷 248-257页

作者： Charles Calvert Jeff Allan Peter Amor stuart Hillmansen Clive Roberts Paul Weston Birmingham Centre for Railway Research and Education School of EngineeringUniversity of BirminghamEdgbastonBirmingham B152TTUK Jeff Vehicles Ltd BeavercreekUSA

In October 2018,Porterbrook and the University of Birmingham announced the HydroFLEX project,to demonstrate a hydrogen-hybrid modified train atRail Live *** concept of modifying a Class 319 Electric Multiple Unit was developed,with equipment including a fuel cell stack,traction battery,24 V control system and hydrogen storage elements to be mounted inside one of the *** was followed by procurement of a fuel cell stack,traction batteries,and control equipment,which was then installed inside the train,being fixed to the seat *** substantial change from the concept was the provision of considerably more hydrogen storage than the minimum necessary,providing the train with more potential to be further modified to allow for higher speed mainline *** the Rail Live exhibition where HydroFLEX was demonstrated,numerous modifications were performed to increase the reliability and power of the HydroFLEX train,primarily concerned with modifying the base train logic,with the aim of a successfulmainline *** this effort was a multitude of documentation concerning safety,operations,and approvals to gain approvals from the relevant approvals *** project demonstrated the feasibility of using hydrogen fuel cells as an autonomous fuel for railway propulsion systems,which has the potential for full decarbonisation.

关键词： Hydrogen Fuel cell Hybrid Systems engineering

The Sherlock Holmes book

在线全文

学校读者我要写书评

暂无评论

Structural integrity and damage of ZrB_(2) ceramics after 4 MeV Au ions irradiation

作者： (author.)Davies David stuart

来源：南通市图书馆图书评论

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2021年第13期72卷 223-230页

作者： Weichao Bao stuart Robertson Jia-Wei Zhao Ji-Xuan Liu Houzheng Wu Guo-Jun Zhang Fangfang Xu State Key Laboratory of High Performance Ceramics and Superfine Microstructure Shanghai Institute of CeramicsShanghai 200050China State Key Laboratory for Modification of Chemical Fibers and Polymer Materials Institute of Functional MaterialsDonghua UniversityShanghai 201620China Department of Materials Loughborough UniversityLeicestershire LE113TUUnited Kingdom

Ultra-high temperature ceramics have been considered as good candidates for plasma facing materials due to their combination of high melting point,high strength and hardness,high thermal conductivity as well as good chemical *** this study,zirconium diboride has been chosen to investigate its irradiation damage *** by 4 MeV Au^(2+)with a total fluence of 2.5×10^(16)cm^(-2),zirconium diboride ceramic shows substantial resilience to irradiation-induced damage with its structural integrity well maintained but mild damage at lattice *** incident X-ray diffraction evidences no change of the hexagonal structure in the irradiated region but its lattice parameter a increased and c decreased,giving a volume shrinkage of 0.46%.Density functional theory calculation shows that such lattice shrinkage corresponds to a non-stoichiometric compound as *** energy-loss spectroscopy in a transmission electron microscope revealed an increase of valence electrons in zirconium,suggesting boron vacancies were indeed developed by the *** ng the irradiation depth,long dislocations were observed inside top layer with a depth of 750 nm where the implanted Au ions reached the peak *** the top layer,a high density of Frank dislocations is formed by the cascade collision down to a depth of 1150 *** the features show the potential of ZrB_(2) to be used as structural material in nuclear system.

关键词： Zirconium diboride Heavy ion irradiation Boron vacancy Dislocation Structure integration

Establishment of Beauveria bassiana as a fungal endophyte in potato plants and its virulence against potato tuber moth, Phthorimaea operculella (Lepidoptera: Gelechiidae)

在线全文

学校读者我要写书评

暂无评论

Insect Science 2023年第1期30卷 197-207页

作者： Meng-Di Zhang Sheng-Yong Wu Jun-Jie Yan stuart Reitz Yu-Lin Gao State Key Laboratory for Biology of Plant Diseases and Insect Pests Institute of Plant ProtectionChinese Academy of Agricultural SciencesBejingChina Department of Crop and Soil Sciences Malheur Experiment StationOregon State UniversityOntarioORUSA National Center of Excellence for Tuber and Root Crop Research Chinese Academy of Agricultural SciencesBeijingChina

The potato tuber moth,Phthorimaea operculella,is the most damaging potato pest in the world and is difficult to control as the larvae are internal feeders in the foliage and *** fungi that colonize plants as endophytes have lethal and sublethal pathological effects on insect *** show that Beauveria bassiana colonizes the aerial parts of potato plants endophytically after inoculation through soil *** *** persisted in potato foliage for more than 50 days *** indicated that foliage of ***-inoculated potato plants were pathogenic against larvae of P *** experiments indicated that *** negatively affected the growth,development,and reproduction of P *** experiments showed that the weight of *** pupae reared on *** potato plants(4.25 mg)was significantly less than that of those reared on uninoculated control plants(8.89mg).Compared with newly eclosed larvaefed on control plants,those fed on ***-inoculated plants had significantly lower survivorship,with only 17.8%developing to the adult *** of P operculella females reared on *** endophytically colonized plants was significantly lower(35 eggs/female)than of those reared on uninoculated plants(115 eggs/female).This study demonstrates that endophytic *** can be a potential biological control agent for the control and management of P *** pupal weights of P operculella reared on potato plants inoculated with the *** strain GZGY-1-3 and on untreated control plants,pupae from the control plants were significantly heavier than those from treated plants.

关键词： Beauveria bassiana biological control colonization Phthorimaea operculella

The performance of the Noblesse multi-collector noble gas mass spectrometer for ^(40)Ar/^(39)Ar geochronology

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

Acta Geochimica 2018年第5期37卷 734-745页

作者： Defeng He Finlay M.stuart Dan N.Barfod Fang Xiao Hong Zhong State Key Laboratory of Ore Deposit Geochemistry Institute of Geochemistry Chinese Academy of Sciences Isotope Geoscience Unit Scottish Universities Environmental Research Centre NERC Argon Isotope Facility Scottish Universities Environmental Research Centre

Noblesse multi-collector noble gas mass spec- trometer is specially designed for multi-collection of Ar isotopes with different beam sizes, especially for small ion beams, precisely, and hence is perfectly suitable for ^40Ar/^39Ar geochronology. We have analyzed widely used sanidine, muscovite, and biotite standards with recom- mended ages of - 1.2-133 Ma, with the aim to assess the reliability of Noblesse for ^40Ar/^39Ar dating. An ESI MIR10 30W CO2 laser was used for total fusion or incremental heating samples. Extracted gases were routinely purified by four SAES NP10 getters （one at - 400 ℃ and others at room temperature）. A GP50 getter and a metal cold finger cooled by liquid N （- 196 ℃） were also attached for additional purification if necessary. The Ar isotopes were then measured by Noblesse using Faraday or multiplier according to the signal intensities. Over a period of 1.5 months 337 air calibrations produced a weighted mean ^40Ar/^36Ar of 296.50 ± 0.08 （2σ, MSWD = 4.77）. Fish Canyon sanidine is used to calculate J-values, which show good linear relationship with position in irradiation. The age of four mineral standards （Alder Creek sanidine, Brione muscovite, Yabachi sanidine, and Fangshan biotite） are within error of the accepted ages. Five Alder Creek sanidine aliquots yielded an age range of 1.174-1.181 ± 0.013 Ma （2σ） which broadly overlaps the established age of the standard and the uncertainty approaches those of the foremost Ar/Ar laboratories in the world. The weighted mean ages of four Brione muscovite aliquots （18.75 i 0.16 Ma, 2σ）, five Yabachi sanidine aliquots （29.50 ± 0.19 Ma, 2σ）, and three Fangshan bio- tite aliquots （133.0 ± 0.76 Ma, 2σ） are consistent with the recommended values of these standards, and the uncer- tainties are typical of modem Ar/Ar laboratories world- wide.

关键词： Ar/Ar geochronology Multi-collector Highprecision Noblesse Age standard