检索结果-南通市图书馆

Response of nephelometric turbidity to hydrodynamic particle size of fine suspended sediment

在线全文

学校读者我要写书评

暂无评论

International Journal of Sediment Research 2020年第5期35卷 444-454页

作者： Christina Bright Sarah Mager Sophie horton School of Geography University of Otago

Turbidity is used as a surrogate for suspended sediment concentration(SSC),and as a regulatory tool for indicating land use disturbance and environmental *** relates linearly to suspended material,however,can show non-linear responses to particulate organic matter(POM),concomitant with changes in particle size distribution(PSD).In the paper the influence of ultra-fine particulate matter(UFPM) on specific turbidity and its association with POM in suspended sediment are shown for alpine rivers in the Southern Alps of New *** approach was two-fold:a field-based investigation of the relations between SSC,POM,and turbidity sampled during event flow;and experimental work on hydrodynamic particle size effects on SSC POM,PSD,and *** turbidity changes over event flow and are sensitive to increasing proportional amounts of sand,UFPM,and POM in ***,the UFPM is the size fraction(<6 μm) where POM *** implications of the current study are that the slopes of turbidity-SSC relations are undesirable in locations that may be dominated by cyclic release of POM or distinct pulses of fine-grained *** locations where the turbidity-SSC slopes approximate 2,the POM proportion is usually <10% of the total suspended ***,when turbidity-SSC slopes are <1 this is likely caused by high amounts of side-scatter from UFPM concomitant with higher proportions of ***,the use of turbidity as a proxy for determining SSC may have serious consequences for the measurement of representative suspended sediment data,particularly in locations where POM may be a significant contributor to overall suspended load.

关键词： Turbidity Nephelometry Suspended sediment concentration Particle size distribution Particulate organic matter

Single and Joint Multifractal Analysis of Soil Particle Size Distributions

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Pedosphere 2011年第1期21卷 75-83页

作者： LI Yi LI Min R. horton Northwest Agriculture and Forestry Sci-Tech University Yangling 712100 (China) Department of Soil Science University of Saskatchewan Saskatoon SK STN 5A8 (Canada) Department of Agronomy Iowa State University Ames IA 50011 (USA)

It is noted that there has been little research to compare volume-based and number-based soil particle size distributions （PSDs）. Our objectives were to characterize the scaling properties and the possible connections between volume-based and number-based PSDs by applying single and joint multifractal analysis. Twelve soil samples were taken from selected sites in Northwest China and their PSDs were analyzed using laser diffractometry. The results indicated that the volume-based PSDs of all 12 samples and the number-based PSDs of 4 samples had multifractal scalings for moment order -6 〈 q 〈： 6. Some empirical relationships were identified between the extreme probability values, maximum probability （Pmax）, minimum probability （Pmin）, and Pmax/Pmin, and the multifractal indices, the difference and the ratio of generalized dimensions at q = 0 and 1 （Do - D1 and D1/Do）, maximum and minimum singularity strength （αmax and OZmin） and their difference （αmax - αmin, spectrum width）, and asymmetric index （RD）. An increase in Pmax generally resulted in corresponding increases of Do - D1, αmax, αmax - αmin, and RD, which indicated that a large Pmax increased the multifractality of a distribution. Joint multifractal analysis showed that there was significant correlation between the scaling indices of volume-based and number-based PSDs. The multifractality indices indicated that for a given soil, the volume-based PSD was more homogeneous than the number-based PSD, and more likely to display monofractal rather than multifractal scaling.

关键词： distribution probability generalized dimensions laser diffractometry scaling singularity strength

Impact of Gully on Soil Moisture of Shrubland in Wind-Water Erosion Crisscross Region of the Loess Plateau

在线全文

学校读者我要写书评

暂无评论

Pedosphere 2008年第5期18卷 674-680页

作者： HUO Zhu SHAO Ming-An R. horton Key Laboratory of Water Cycle and Related Land Surface Processes Institute of Geographical Sciences and Natural Resources Research Chinese Academy of Sciences Beijing 100101 （China）. Graduate University of the Chinese Academy of Sciences Beijing 100049 （China） Agronomy Department of Iowa State University Ames IA 50011-1010 （USA）

The most serious erosion on the Loess Plateau of China exists in the wind-water erosion crisscross region where the annual precipitation is about 400 mm,the ecological environment is very fragile,and water is the key limiting factor for improving the environment. In this study,changes of soil moisture content for Caragana korshinskii Kom. shrubland in the gully bank of the Loess Plateau were studied using the methods of soil sampling and neutron probe. A typical gully(75 m long,28 m wide,and 10 m deep) was selected,and six neutron probe access tubes(6 m long) were installed at points 50,100,200,300,400,and 500 cm from the gully border for obtaining soil moisture data from July to October 2004 at approximately 10 d intervals. Soil samplings were simultaneously carried out for moisture determination at the six points. Results showed that the soil moisture of the shrubland in the gully bank significantly varied between 300 and 400 cm in the horizontal direction and up to 600 cm in vertical direction of the gully. Seasonal changes in soil moisture revealed a curve with a single peak that occurred at the end of August or early September. A linear regression equation was fit for soil water storage and the distance from the gully border,with coefficients depending on rainfall characteristics,sampling point,and time of measurement.

关键词： erosion gully shrubland soil moisture

A charge-density-based general cation insertion algorithm for generating new Li-ion cathode materials

在线全文

学校读者我要写书评

暂无评论

npj Computational Materials 2020年第1期6卷 336-342页

作者： Jimmy-Xuan Shen Matthew horton Kristin A.Persson Department of Materials Science and Engineering University of CaliforniaBerkeleyBerkeleyCA 94720USA Energy Technologies Area Lawrence Berkeley National LaboratoryBerkeley 94720USA

Future lithium(Li)energy storage technologies,in particular solid-state configurations with a Li metal anode,opens up the possibility of using cathode materials that do not necessarily contain Li in its as-made *** accelerate the discovery and design of such materials,we develop a general,chemically,and structurally agnostic methodology for identifying the optimal Li sites in any crystalline *** a given crystal structure,we attempt multiple Li insertions at symmetrically in-equivalent positions by analyzing the electronic charge density obtained from first-principles density functional *** this report,we demonstrate the effectiveness of this procedure in successfully identifying the positions of the Li ion in well-known cathode materials using only the empty host(charged)material as ***,applying the algorithm to over 2000 candidate cathode empty host materials we obtain statistics of Li site preferences to guide future developments of novel Li-ion cathode materials,particularly for solid-state applications.

关键词： charge insertion algorithm

An Analytical Solution for One-Dimensional Water Infiltration and Redistribution in Unsaturated Soil

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Pedosphere 2009年第1期19卷 104-110页

作者： WANG Quan-Jiu R. horton FAN Jun Institute of Water Resources Research Xi＇an University of Technology Xi＇an 710048 （China） State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau Institute of Soil and Water Conservation Chinese Academy of Sciences and Ministry of Water Resources Yangling 712100 （China） Department of Agronomy Iowa State University Ames IA 50011 （USA）

Soil infiltration and redistribution are important processes in field water cycle, and it is necessary to develop a simple model to describe the processes. In this study, an algebraic solution for one-dimensional water infiltration and redistribution without evaporation in unsaturated soil was developed based on Richards equation. The algebraic solution had three parameters, namely, the saturated water conductivity, the comprehensive shape coefficient of the soil water content distribution, and the soil suction allocation coefficient. To analyze the physical features of these parameters, a relationship between the Green-Ampt model and the algebraic solution was established. The three parameters were estimated based on experimental observations, whereas the soil water content and the water infiltration duration were calculated using the algebraic solution. The calculated soil water content and infiltration duration were compared with the experimental observations, and the results indicated that the algebraic solution accurately described the unsaturated soil water flow processes.

关键词： algebraic solution Green-Ampt model soil water infiltration and redistribution unsaturated soil

WoRMS needs YOU!A Reply to Collareta et al.2020

在线全文

学校读者我要写书评

暂无评论

Integrative Zoology 2022年第2期17卷 326-327页

作者： Tammy horton Andreas KROH Leen VANDEPITTE National Oceanography Centre SouthamptonUK Natural History Museum Vienna Austria Flanders Marine Institute(VLIZ) Wandelaarkaai 7OostendeBelgium

Editorial Note:“This response to Collareta et al.(2020)was reviewed by several taxonomists,all who expressed a degree of misgiving about the editorial processes and protocols involved in the revision of the Thoracica and publication of this revision in *** is critical that future editors ensure that any taxonomic revision is supported by peer-reviewed publication.”

关键词： al. revision Col

Age at reproductive maturity and effect of age and time of day on sex attraction in the potato psyllid Bactericera cockerelli

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Insect Science 2012年第5期19卷 585-594页

作者： Christelle Guedot David R. horton Peter J. Landolt U.S. Department of Agriculture Agricultural Research Service 5230 Konnowac Pass Road Wapato WA 98951 USA

The potato psyllid, Baetericera （= Paratrioza） cockerelli （gulc）（Hemiptera： Triozidae）, is a major pest of potato. Studies were conducted to determine the age at which both males and females reach reproductive maturity and the effect of age and time of day on sex attraction. Adult B. cockerelli reach reproductive maturity within 48 h post-eclosion, with females being mature on the day of eclosion and males at 1 day post-eclosion. Oviposition generally began 2 days after mating but was delayed when females mated within 2 days post-eclosion. In laboratory olfactometer assays, the age of females used as odor sources and the age of males assayed to these odors did not affect sex attraction, with both younger （1-4-day-old） and older （8-10-day-old） males being attracted to females, regardless of female age （1-4-day-old or 8-10-day-old）. Males assayed to live females at different times during the photophase （between 8：00 and 20：00 hours） were attracted to females between 11：00 and 17：00 hours, showing a temporal periodicity in sex attraction with B. cockerelli at least during the photophase.

关键词： mate attraction olfactometer oviposition periodicity potato preference,Triozidae

High-throughput prediction of the ground-state collinear magnetic order of inorganic materials using Density Functional Theory

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

npj Computational Materials 2019年第1期5卷 588-598页

作者： Matthew Kristofer horton Joseph Harold Montoya Miao Liu Kristin Aslaug Persson Energy Technologies Area Lawrence Berkeley National LaboratoryBerkeleyCAUSA Institute of Physics Chinese Academy of SciencesBeijingChina Department of Materials Science University of California BerkeleyBerkeleyCA 94720USA

We present a robust,automatic high-throughput workflow for the calculation of magnetic ground state of solid-state inorganic crystals,whether ferromagnetic,antiferromagnetic or ferrimagnetic,and their associated magnetic moments within the framework of collinear spin-polarized Density Functional *** is done through a computationally efficient scheme whereby plausible magnetic orderings are first enumerated and prioritized based on symmetry,and then relaxed and their energies determined through conventional DFT+U *** automated workflow is formalized using the atomate code for reliable,systematic use at a scale appropriate for thousands of materials and is fully *** performance of the workflow is evaluated against a benchmark of 64 experimentally known mostly ionic magnetic materials of non-trivial magnetic order and by the calculation of over 500 distinct magnetic orderings.A non-ferromagnetic ground state is correctly predicted in 95% of the benchmark materials,with the experimentally determined ground state ordering found exactly in over 60% of *** of the ground state magnetic order at scale opens up the possibility of high-throughput screening studies based on magnetic properties,thereby accelerating discovery and understanding of new functional materials.

关键词： state ground ferromagnetic

Engineering the atomic interface of porous ceria nanorod with single palladium atoms for hydrodehalogenation reaction

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Nano Research 2022年第2期15卷 1338-1346页

作者： Zhijun Li Mingyang Zhang Lili Zhang Xiuli Dong Leipeng Leng JHugh horton Jun Wang Joint International Research Laboratory of Advanced Chemical Catalytic Materials&Surface Science College of Chemistry and Chemical EngineeringNortheast Petroleum UniversityDaqing 163318China Shenyang National Laboratory for Materials Science Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China Department of Chemistry Queens UniversityKingstonK7L 3N6Canada

Tuning the electronic properties of single atom catalysts(SACs)between the central metal and the neighboring surface atoms has emerged as an efficient strategy to boost catalytic efficiency and metal *** we describe a simple and efficient approach to create atomically dispersed palladium atoms supported over defect-containing porous ceria nanorod containing palladium up to 0.26 wt.%.The existence of singly dispersed palladium atoms is confirmed by spherical aberration correction electron microscopy and extended X-ray absorption fine structure *** catalyst shows excellent efficiency in hydrodehalogenation reactions at low H2 pressure under mild conditions,along with satisfactory recyclability and *** functional theory(DFT)calculations reveal that the high activity stems from the spatial isolation of palladium atoms and the modified electronic structure of palladium confined in defect-containing ceria *** work may lay the foundation for the facile creation of single atom catalysts within the synthetic community and shed light on the possibility for scale-up production.

关键词： heterogeneous catalysis palladium single atom catalyst porous ceria nanorod hydrodehalogenation catalytic activity