检索结果-南通市图书馆

The CCD instrument background of the SMILE SXI

在线全文

学校读者我要写书评

暂无评论

Earth and Planetary Physics 2024年第1期8卷 15-24页

作者： M.W.J.hubbard O.Hetherington D.J.Hall T.W.Buggey S.Parsons T.Arnold A.Holland C.Pagani S.Sembay Centre for Electronic Imaging The Open UniversityMilton KeynesMK76AAUK X-ray and Observational Astronomy Group Department of Physics&AstronomyUniversity of LeicesterLE17RHUK

The ESA and CAS SMILE mission orbit is highly elliptical and will pass through multiple radiation *** Soft X-ray Imager(SXI)instrument aboard has a radiation shutter door designed to close when the surrounding radiation flux is *** shutter door will close when passing below an altitude threshold to protect against trapped particles in the Earth’s Van Allen ***,two radiation environments can be approximated based on the shutter door position:open and *** instrument background for the CCDs(Charge-Coupled Devices)that form the focal plane array of the SXI were evaluated for the two *** to the correlation of the space environment with the solar cycle,the solar minima and maxima,the background was also evaluated at these two *** results demonstrated that the highest instrument background will occur during solar minima due to the main contributing source being Galactic Cosmic Rays(GCRs).It was also found that the open background was highest for solar minima and that the closed background was highest during solar *** is due to the radiation shutter door acting as a scattering centre and the changes in the energy flux distribution of the GCRs between the two solar extremes.

关键词： instrument background X-ray astronomy space radiation

Acknowledgment of Libraries in the Journal Literature: An Exploratory Study

在线全文

学校读者我要写书评

暂无评论

Journal of Data and Information Science 2020年第3期5卷 178-186页

作者： David E.hubbard Sierra Laddusaw Texas A&M University University LibrariesTAMU 5000 College StationTexas 77843USA

Purpose: This study examines acknowledgments to libraries in the journal literature, as well as the efficacy of using Web of Science(WoS) to locate general acknowledgment ***/methodology/approach: This mixed-methods approach quantifies and characterizes acknowledgments to libraries in the journal literature. Using WoS's Funding Text field, the acknowledgments for six peer universities were identified and then characterized. The efficacy of using WoS to locate library acknowledgments was assessed by comparing the WoS Funding Text search results to the actual acknowledgment text found in the ***: Acknowledgments to libraries were found in articles at all six peer universities, though the absolute and relative numbers were quite low(< 0.5%). Most of the library acknowledgments were for resources(collections, funding, etc.), and many were concentrated in natural history(e.g. zoology). Examination of Texas A&M University zoology articles found that 91.7% of the funding information came from "acknowledgments" and not specifically a funding acknowledgment section. The WoS Funding Text search found 56% of the library acknowledgments compared to a search of the actual acknowledgment text in the *** limitations: Limiting publications to journals, using a single truncated search term, and including only six research universities in the United *** implications: This study examined library acknowledgments, but the same approach could be applied to searches of other keywords, institutions/organizations, individuals, etc. While not specifically designed to search general acknowledgments, WoS's Funding Text field can be used as an exploratory tool to search acknowledgments beyond funding. Originality/value: There are a few studies that have examined library acknowledgments in the scholarly literature, though to date none of those studies have examined the efficacy of using the WoS Funding Text field to locate those library acknowledg

关键词： Acknowledgment Bibliometric analysis Libraries Web of Science

A Comparison of Elementary Foreign Language Programs in China and the USA

在线全文

学校读者我要写书评

暂无评论

Fudan Journal of the Humanities and Social Sciences 2021年第3期14卷 319-344页

作者： Qi Si Janie hubbard Department of Curriculum and Instruction The University of AlabamaBox 870232TuscaloosaAlabama 35487USA

This study presents comparisons regarding current elementary foreign language programs in China and the *** design features a comparative analysis approach combined with deductive thematic analysis to collect,analyze,and compare relevant *** were collected from samples such as governmental documents,organizational guidelines,national statistical reports,published scholarly works,audiovisual materials,and *** the research,primary categories were identified,used to group data,and then look for similarities and *** for comparison were:(a)program types,(b)curriculum standards,(c)instructional methods,and(d)*** indicated US programs could benefit from consistency,widespread support and demand,state-to-state organization and/or alignment,equitable teaching materials,and attention to all student ***'s program,while organized,could benefit from more authentic,real-life-context,other-culture-oriented practices,flexibility,and deeper,genuine information about English-speaking countries’*** research contributes to scholarly conversations regarding comparisons of elementary foreign language teaching in China and the USA,while also supporting worldwide comparisons and exchange of ideas.

关键词： Elementary education Foreign language programs Global comparison China and US education

Assessment of widely used methods to derive depositional ages from detrital zircon populations

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Geoscience Frontiers 2019年第4期10卷 1421-1435页

作者： Daniel S.Coutts William A.Matthews Stephen M.hubbard Department of Geoscience University of Calgary

The calculation of a maximum depositional age(MDA)from a detrital zircon sample can provide insight into a variety of geological ***,the impact of sample size and calculation method on the accuracy of a resulting MDA has not been *** use large populations of synthetic zircon dates(N≈25,000)to analyze the impact of varying sample size(n),measurement uncertainty,and the abundance of neardepositional-age zircons on the accuracy and uncertainty of 9 commonly used MDA calculation ***,a new method,the youngest statistical population is *** each method,500 samples of n synthetic dates were drawn from the parent population and MDAs were *** mean and standard deviation of each method ove r the 500 trials at each n-value(50-1000,in increments of 50)were compa red to the known depositional age of the synthetic population and used to compare the methods quantitatively in two simulation *** first simulation scenario varied the proportion of near-depositional-age grains in the synthetic *** second scenario varied the uncertainty of the dates used to calculate the *** sample size initially decreased the mean residual error and standard deviation calculated by each *** higher n-values(>~300 grains),calculated MDAs changed more slowly and the mean resid ual error increased or decreased depending on the method *** the p roportion of near-depositional-age grains and lowering measurement uncertainty decreased the number of measurements required for the calculated MDAs to stabilize and decreased the standard deviation in calculated MDAs of the 500 *** of the two simulation scenarios show that the most successful way to increase the accuracy of a calculated M DA is by acquiring a large number of low-uncertainty measurements(300300)approach is used if the calculation of accurate MDAs are key to research *** acquisition method s,such as high-to moderate-precision m

关键词： Detrital zircon Maximum depositional age Geochronology Basin chronology LA-ICP-MS

Velocity-Based Moving Mesh Methods for Nonlinear Partial Differential Equations

在线全文

学校读者我要写书评

暂无评论

Communications in Computational Physics 2011年第8期10卷 509-576页

作者： M.J.Baines M.E.hubbard P.K.Jimack Department of Mathematics The University of ReadingRG66AXUK. School of Computing University of LeedsLS29JTUK

This article describes a number of velocity-based moving mesh numerical methods for multidimensional nonlinear time-dependent partial differential equations(PDEs).It consists of a short historical review followed by a detailed description of a recently developed multidimensional moving mesh finite element method based on *** element algorithms are derived for both mass-conserving and non mass-conserving problems,and results shown for a number of multidimensional nonlinear test problems,including the second order porous medium equation and the fourth order thin film equation as well as a two-phase *** applications and extensions are referenced.

关键词： Time-dependent nonlinear diffusion moving boundaries finite element method Lagrangian meshes conservation of mass

Opportunities for Recruiting and Training Construction Workers in the Transportation Sector

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Civil Engineering and Architecture 2011年第7期5卷 576-584页

作者： Bryan John hubbard Sarah Marie Lillo hubbard Department of Building Construction Management Purdue University West Lafayette 47907 USA Department of Civil Engineering Purdue University West Lafayette 47907 USA

The recent slowdown in the residential and commercial building sectors has resulted in significant unemployment. Given the experience of these construction workers, it may be appropriate for transportation and public works agencies to assess the potential to retrain these workers for the transportation sector. This widens the pool of available workers, and brings workers with compatible skill sets to the transportation industry. This paper examines the pool of eligible workers, discusses the potential benefits and challenges of bringing these workers into the transportation sector, and identifies programs that have been undertaken to re-train workers for the transportation sector. A program to re-train construction workers from the residential and commercial sector for the transportation sector is presented, including specific training issues to facilitate the successful transition from residential and commercial construction to transportation construction.

关键词： Construction training safety.

A Moving-Mesh Finite Element Method and its Application to the Numerical Solution of Phase-Change Problems

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 2009年第8期6卷 595-624页

作者： M.J.Baines M.E.hubbard P.K.Jimack R.Mahmood Department of Mathematics The University of ReadingUK School of Computing University of LeedsUK Computer Division Pakistan Institute of Nuclear Science and Technology(PINSTECH)IslamabadPakistan

A distributed Lagrangian moving-mesh finite element method is applied to problems involving changes of *** algorithm uses a distributed conservation principle to determine nodal mesh velocities,which are then used to move the *** nodal values are obtained from an ALE(Arbitrary Lagrangian-Eulerian)equation,which represents a generalization of the original algorithm presented in Applied Numerical Mathematics,54:450–469(2005).Having described the details of the generalized algorithm it is validated on two test cases from the original paper and is then applied to one-phase and,for the first time,two-phase Stefan problems in one and two space dimensions,paying particular attention to the implementation of the interface boundary *** are presented to demonstrate the accuracy and the effectiveness of the method,including comparisons against analytical solutions where available.

关键词： Moving mesh method finite elements multiphase flows interface tracking

A review of sustainability metrics for the construction and operation of airport and roadway infrastructure

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Frontiers of Engineering Management 2019年第3期6卷 433-452页

作者： Sarah M.L.hubbard Bryan hubbard School of Aviation and Transportation Technology Purdue UniversityWest LafayetteIN 47907USA School of Building Construction Management Technology Purdue UniversityWest LafayetteIN 47907USA

Sustainability has become increasingly important,however,relatively little attention has focused on metrics for the construction and operation of airport and roadway *** attention has focused on buildings,with high profile BREEAM and LEED projects taking center *** is also important in airport and roadway infrastructure projects,which have significant public impact but have a much lower profile than vertical construction when it comes to *** infrastructure is important in China and India where new infrastructure is under construction to meet growing and developing economies,and in the US,where infrastructure is in substandard condition and requires *** purpose of this paper is to provide an overview and discussion of sustainability rating systems for airport and roadway infrastructure,including both construction and *** projects that highlight both proven and innovative sustainable practices are included to illustrate the application of these ***,the relationship between sustainable transportation infrastructure and resilient transportation infrastructure is addressed since resiliency is of growing interest and there is overlap between these concepts.

关键词： sustainable construction infrastructure airport roadway resiliency sustainability

Male zebrafish(Danio rerio)odorants attract females and induce spawning

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Aquaculture and Fisheries 2018年第4期3卷 139-144页

作者： Jie Li Peter C.hubbard Adelino V.M.Canario College of Fisheries and Life Science Shanghai Ocean UniversityShanghai 201306China Centro de Ciencias do Mar Universidade do AlgarveCampus de Gambelas8005-139FaroPortugal

In zebrafish,the chemical identity and biological roles of reproductive pheromones have yet to be *** current study assessed the role(s)of male-released odorants in a reproductive context,and evaluated the possible involvement of steroids and their *** were placed in chemical and/or visual contact with *** chemical contact,females ovulated as frequently whether they could see the males or ***,females with visual contact alone with males ovulated as frequently as isolated ***-released odorants attracted females;visual contact with males attracted females,but to a lesser extent;the two effects were *** olfactory potency of solid-phase extraction of male-and female-conditioned water was assessed by the electro-olfactogram;males released more potent odorants than females,but the most potent extract came from water in which males and females interacted *** fractionation of these extracts revealed that,while in all samples some fractions contained odorants,male-specific activity was contained in the first four fractions,suggesting that the compounds involved are relatively ***,the olfactory potency of some steroids,previously suggested to have a pheromonal role,was ***,it is unlikely that these steroids contribute significantly to the odor of fish-conditioned water.

关键词： Pheromone Zebrafish Reproduction Behavior Olfaction Spawning