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Scale Effects of Geographical Soil Datasets on Soil Carbon Estimation in Louisiana,USA:A Comparison of STATSGO and SSURGO

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Pedosphere 2011年第4期21卷 491-501页

作者： B. ZHONG y. J. XU School of Renewable Natural Resources Louisiana State University Agricultural Center Baton Rouge LA 70803 (USA)

Estimation of soil organic carbon （SOC） pools and fluxes bears large uncertainties because SOC stocks vary.greatly.over geographical space and through time. Although development of the U.S. Soil Survey.Geographic Database （SSURGO）, currently.the most detailed level with a map scale ranging from 1：12 000 to 1：63 360, has involved substantial government funds and coordinated network efforts, very.few studies have utilized it for soil carbon assessment at the large landscape scale. The objectives of this study.were to 1） compare estimates in soil organic matter among SSURGO, the State Soil Geographic Database （STATSGO）, and referenced field measurements at the soil map unit; 2） examine the influence of missing data on SOC estimation by.SSURGO and STATSGO; 3） quantify.spatial differences in SOC estimation between SSURGO and STATSCO, specifically.for the state of Louisiana; and 4） assess scale effects on soil organic carbon density.（SOCD） estimates from a soil map unit to a watershed and a river basin scale. SOC was estimated using soil attributes of SSURGO and STATSGO including soil organic matter （SOM） content, soil lay.r depth, and bulk density. Paired t-test, correlation, and regression analy.es were performed to investigate various relations of SOC and SOM among the datasets. There were positive relations of SOC estimates between SSURGO and STATSGO at the soil map unit （R2 = 0.56, n = 86, t = 1.65, P = 0.102; depth： 30 cm）. However, the SOC estimated by.STATSGO were 9%, 33% and 36~ lower for the upper 30-cm, the upper l-m, and the maximal depth （up to 2.75 m） soils, respectively. than those from SSURGO. The difference tended to increase as the spatial scale changes from the soil map unit to the watershed and river basin scales. Compared with the referenced field measurements, the estimates in SOM by.SSURGO showed a closer match than those of STATSCO, indicating that the former was more accurate than the latter in SOC estimation, both in spatial and temporal resoluti

关键词： carbon accounting climate change GIS soil organic carbon soil organic matter

Forest biodiversity. relationships to structural and functional attributes, and stability.in New England forests

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Forest Ecosy.tems 2018年第2期5卷 177-188页

作者： y.de Pan Kevin McCullough David y. Hollinger USDA Forest Service Durham NH USA USDA Forest Service Madison WI USA

Background： Forest biodiversity.is the foundation of many.ecosy.tem services, and the effect of biodiversity.on ecosy.tem functioning and processes （BEF） has been a central issue in biodiversity.studies. Although many.hy.otheses have been developed to interpret global gradients of biodiversity. there has not been complete agreement on mechanisms controlling biodiversity.patterns and distributions. Differences may.be due to limited observation data and inconsistencies of spatial scales in analy.is. Methods： In this study. we take advantage of USDA Forest Service forest inventory.and analy.is （FIA） data for exploring regional forest biodiversity.and BEF in New England forests. The FIA data provide detailed information of sampled plots and trees for the region, including 6000 FIA plots and more than 33,000 individual trees. Biodiversity.models were used to analy.e the data. Results： Tree species diversity.increases from the north to the south at a rate about 2-3 species per latitudinal degree. Tree species diversity.is better predicted by.tree height than forest age or biomass. Very.different distribution patterns of two common maple species, sugar maple （Acer sdcchorum） and red maple （Acer rubrum）, highlight the vulnerability.of sugar maple and its potential replacement by.red maple on New England landscapes. Red maple generally.already.outperforms sugar maple, and will likely.and continuously.benefit from a changing climate in New England. Conclusions： We conclude that forest structure （height） and resources （biomass） are more likely.foundational characteristics supporting biodiversity.rather than biodiversity.determining forest productivity.and/or biomass. The potential replacement of red maple for sugar maple in the New England areas could affect biodiversity.and stability.of forest ecosy.tem functioning because sugar maple play. important ecological roles distinct from red maple that are beneficial to other tree species in northern hardwood forests. Such a change

关键词： Forest biodiversity Biodiversity.effect on function (BEF) New England Forest inventory.data Species diversity Latitudinal diversity.gradient Forest stability.of ecosy.tem functioning Forest resilience Sugar maple Red maple Changing climate

Tuning periodicity.of poly.er-decorated carbon nanotubes

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Science China Chemistry 2012年第5期55卷 802-807页

作者： LAIRD Eric D. LI Christopher y. A. J. Drexel Nanotechnology.Institute and Department of Materials Science and Engineering Drexel University Philadelphia Pennsylvania 19104 USA

Carbon nanotube (CNT) is one of the most extensively.investigated nanomaterials. Patterning soft matter such as liquid cry.tals and poly.ers on CNTs could potentially.enable various applications for CNTs. We have demonstrated that controlled poly.er cry.tallization using CNTs as the 1D nucleation sites can lead to periodically.functionalized CNTs. Here we show that selected cry.talline block copoly.ers can be periodically.decorated along CNTs. This facile technique opens a gateway.to periodic patterning on 1-D nanomaterials.

关键词： poly.er cry.tallization carbon nanotube block copoly.ers

Topological Poly.er Chemistry.for Designing New Macromolecular Architectures

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复旦学报（自然科学版） 2005年第5期44卷 844-845页

作者： y. Tezuka Department of Organic and Poly.eric Materials Tokyo Institute of Technology Tokyo 152-8552 Japan

The precise control in poly.er architectures has been an ongoing challenge in sy.thetic poly.er chemistry. since new poly.er topologies will realize unprecedented properties and functions in poly.eric *** particular, topologically.unique macromolecules comprising single cy.lic and multicy.lic poly.er units have gained growing interests due to their distinctive behaviors from linear and branched counterparts[1-4]. See Fig. 1.

关键词：遥爪聚合体拓扑结构静电自组合大分子结构合成方法

Asy.metry.aware load balancing for parallel applications in single-ISA multi-core sy.tems

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Journal of Zhejiang University.Science C(Computers and Electronics) 2012年第6期13卷 413-427页

作者： Eunsung KIM Hy.onsang EOM Heon y. y.OM School of Computer Science and Engineering Seoul National University Seoul 151-744 Korea

Contemporary.operating sy.tems for single-ISA （instruction set architecture） multi-core sy.tems attempt to distribute tasks equally.among all the CPUs. This approach works relatively.well when there is no difference in CPU capability. However, there are cases in which CPU capability.differs from one another. For instance, static capability.asy.metry.results from the advent of new asy.metric hardware, and dy.amic capability.asy.metry.comes from the operating sy.tem （OS） outside noise caused from networking or I/O handling. These asy.metries can make it hard for the OS scheduler to evenly.distribute the tasks, resulting in less efficient load balancing. In this paper, we propose a user-level load balaneer for parallel applications, called the ＇capability.balancer＇, which recognizes the difference of CPU capability.and makes subtasks share the entire CPU capability.fairly. The balancer can coexist with the existing kemel-level load balancer without detrimenting the behavior of the kernel balancer. The capability.balancer can fairly.distribute CPU capability.to tasks with very.little overhead. For real workloads like the NAS Parallel Benchmark （NPB）, we have accomplished speedups of up to 9.8% and 8.5% in dy.amic and static asy.metries, respectively. We have also experienced speedups of 13.3% for dy.amic asy.metry.and 24.1% for static asy.metry.in a competitive environment. The impacts of our task selection policies, FIFO （first in, first out） and cache, were compared. The use of the cache policy.led to a speedup of 5.3% in overall execution time and a decrease of 4.7% in the overall cache miss count, compared with the FIFO policy. which is used by.default.

关键词： Scheduler Load balancing Capability.asy.metry OS noise Multi-core

Sy.thesis and Thermal Property.of the Poly.silpheny.lenesiloxane)s with Functional Groups

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复旦学报（自然科学版） 2005年第5期44卷 798-799页

作者： y. Kawakami Japan Advanced Institute of Science and Technology.(JAIST) 1-1 Asahidai Nomi Ishikawa 923-1292 Japan

Silicon-containing poly.ers have been intensively.studied in the past half-century. and a great number of papers, patents and books have been published on the sy.thesis, properties and applications. Silicon-containing poly.ers, especially.poly.ers containing silicon atoms in the backbone, including some major species as poly.iloxane, poly.ilane, poly.ilazane, etc. have chains constructed of alternately.arranged silicon and oxy.en atoms with organic groups attached to the silicon atoms, which are the most important silicon-containing poly.ers so far.

关键词：聚乙烯热性质功能组氢化硅烷化

Closed-form solutions for free vibration of rectangular FGM thin plates resting on elastic foundation

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Acta Mechanica Sinica 2016年第6期32卷 1088-1103页

作者： T. F. Xu y. F. Xing Institute of Solid Mechanics Beihang UniversityBeijing 100191 China China Academy.of Launch Vehicle Technology.R&D Center Beijing 100076 China

This article presents closed-form solutions for the frequency.analy.is of rectangular functionally.graded material (FGM) thin plates subjected to initially.in-plane loads and with an elastic foundation. Based on classical thin plate theory. the governing differential equations are derived using Hamilton's principle. A neutral surface is used to eliminate stretching-bending coupling in FGM plates on the basis of the assumption of constant Poisson's ratio. The resulting governing equation of FGM thin plates has the same form as homogeneous thin plates. The separation-of-variables method is adopted to obtain solutions for the free vibration problems of rectangular FGM thin plates with separable boundary.conditions, including, for example, clamped plates. The obtained normal modes and frequencies are in elegant closed forms, and present formulations and solutions are validated by.comparing present results with those in the literature and finite element method results obtained by.the authors. A parameter study.reveals the effects of the power law index n and aspect ratio a/b on frequencies.

关键词： Functionally.graded material Free vibration Rectangular plate Close form solutions Neutral surface

New approaches to water purification for resource- constrained settings： Production of activated biochar by.chemical activation with diammonium hy.rogenphosphate

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Frontiers of Chemical Science and Engineering 2018年第1期12卷 194-208页

作者： Mohit Nahata Chang y. Seo Pradeep Krishnakumar Johannes Schwank Department of Chemical Engineering University of Michigan-Ann Arbor Ann Arbor MI 48109 USA

A significant portion of the world＇s population does not have access to safe drinking water. This problem is most acute in remote, resource-constrained rural settings in developing countries. Water filtration using activated carbon is one of the important steps in treating con- taminated water. Lignocellulosic biomass is generally.available in abundance in such locations, such as the African rain forests. Our work is focused on developing a simple method to sy.thesize activated biochar from locally.available materials. The preparation of activated biochar with diammonium hy.rogenphosphate （DAP） as the activating agent is explored under N2 flow and air. The study. carried out with cellulose as a model biomass, provides some insight into the interaction between DAP and biomass, as well as the char forming mechanism. Various characterization techniques such as N2 phy.isorption, X-ray.photoelectron spectroscopy. scanning electron microscopy. transmission electron microscopy.and Raman spectroscopy.are utilized to compare the properties between biochar formed under nitrogen and partial oxidative conditions. At a temperature of 450 ℃, the loading of DAP over cellulose is sy.tematically.varied, and its effect on activation is examined. The activated biochar samples are predominantly.microporous in the range of concentrations studied. The interaction of DAP with cellulose is investigated and the nature of bonding of the heteroatoms to the carbonaceous matrix is elucidated. The results indicate that the quality.of biochar prepared under partial oxidation condition is comparable to that ofbiochar prepared under nitrogen, leading to the possibility.of an activated biochar production scheme on a small scale in resource-constrained settings.

关键词： cellulose DAP activation heteroatom,microporous

A method for analy.ing on-line video images of cry.tallization at high-solid concentrations

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Particuology 2008年第1期6卷 9-15页

作者： Jian Wan Cai y. Ma Xue Z. Wang Institute of Particle Science and Engineering School of Process Environmental and Materials Engineering University of Leeds Leeds LS2 9JT UK

Recent research has demonstrated that on-line video imaging is a very.promising technique for monitoring cry.tallization processes. The bottleneck in apply.ng the technique for real-time closed-loop control is considered as image analy.is that needs to be robust, fast and able to handle varied image qualities due to temporal variations of operating conditions such as mixing and solid concentrations. Image analy.is at highsolid concentrations turns out to be extremely.challenging because cry.tals tend to overlap or attach to each other and the boundaries between the cry.tals are usually.ambiguous. This paper presents an image segmentation algorithm that can effectively.deal with images taken at high-solid concentrations. The method segments cry.tals attached to each other along the mostly.related concave points on the contours of cry.tal blocks. The detailed procedure is introduced with application to cry.tallization of L-glutamic acid in a hot-stage reactor.

关键词： Cry.tallization High-solid concentrations Image processing Multi-scale segmentation Watershed segmentation Cry.tal size distribution