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Responses of Lowland, Upland and Aerobic Rice Genotypes to Water Limitation During Different Phases

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Rice science 2020年第4期27卷 345-354页

作者： Preethi VIJAYARAGHAVAREDDY YIN Xinyou Paul CSTRUIK Udayakumar MakARLA Sheshshayee SREEMAN Department of Crop Physiology University of Agricultural SciencesBengaluru 560065India Centre for Crop Systems Analysis Wageningen University&ResearchPO Box 4306700AK Wageningenthe Netherlands

Rice yield reduction due to water limitation depends on its severity and duration and on the phenological stage of its *** exposed three contrasting rice genotypes,IR64,UPLRi7 and Apo(adapted to lowland,upland and aerobic conditions,respectively),to three water regimes(puddle,100%and 60%field capacity)in pots during the vegetative(GSI),flowering(GSII)and grain filling(GSIII)*** at all the three stages significantly reduced yield especially in lowland genotype *** of water limitation was more severe at GSII than at the other two *** at GSI stage reduced both source activity(leaf area and photosynthetic rate)and sink capacity(tiller number or panicle number per pot).When stress was imposed at GSII,spikelet fertility was most affected in all the three *** both GSII and GSIII,although leaf area was constant in all the three water regimes,estimated relative whole-plant photosynthesis was strongly associated with yield *** photosynthesis due to stress at any given stage was found to have direct impact on *** to the other genotypes,Apo had deeper roots and maintained a better water relation,thus,higher carbon gain and spikelet viability,and ultimately,higher biomass and productivity under water-limited ***,screening for these stage-dependent adaptive mechanisms is crucial in breeding for sustained rice production under water limitation.

关键词： water limitation phenology upland aerobic Oryza sativa yield

Ocean Mixing with Lead-Dependent Subgrid Scale Brine Rejection Parameterization in a Climate Model

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Journal of Ocean University of China 2012年第4期11卷 473-480页

作者： Meibing Jin Jennifer Hutchings Yusuke Kawaguchi Takashi Kikuchi International Arctic Research Center University of Alaska Fairbanks AK 99709 USA Japan Agency for Marine-Earth Science and Technology Yokosuka 237-0061 Japan

Sea ice thickness is highly spatially variable and can cause uneven ocean heat and salt flux on subgrid scales in climate *** studies have demonstrated improvements in ocean mixing simulation using parameterization schemes that distribute brine rejection directly in the upper ocean mixed *** this study,idealized ocean model experiments were conducted to examine modeled ocean mixing errors as a function of the lead fraction in a climate model *** the lead is resolved by the grid,the added salt at the sea surface will sink to the base of the mixed layer and then spread *** averaged at a climate-model grid size,this vertical distribution of added salt is lead-fraction *** the lead is unresolved,the model errors were systematic leading to greater surface salinity and deeper mixed-layer depth(MLD).An empirical function was developed to revise the added-salt-related parameter n from being fixed to lead-fraction *** of this new scheme in a climate model showed significant improvement in modeled wintertime salinity and MLD as compared to series of CTD data sets in 1997/1998 and 2006/*** results showed the most evident improvement in modeled MLD in the Arctic Basin,similar to that using a fixed n=5,as recommended by the previous Arctic regional model study,in which the parameter n obtained is close to 5 due to the small lead fraction in the Arctic Basin in winter.

关键词： climate model sea ice brine rejection ocean mixing parameterization

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ak微博控收藏二手车

汽车知识 2012年第3期 74-78页

收藏汽车无论在国外还是国内都不算什么新鲜事,国内的汽车文化虽然刚刚兴起,但汽车收藏也算有了一段时间。与以往我们认识到的汽车收藏不同,80后们创建了一个全新的汽车收藏流派,他们收藏的汽车大多都是在他们幼年生长时期盛行的车型,... 详细信息

收藏汽车无论在国外还是国内都不算什么新鲜事,国内的汽车文化虽然刚刚兴起,但汽车收藏也算有了一段时间。与以往我们认识到的汽车收藏不同,80后们创建了一个全新的汽车收藏流派,他们收藏的汽车大多都是在他们幼年生长时期盛行的车型,或者是和他们同年诞生的车型。本期ak微博控就讨论二手车收藏的话题。

关键词：微博控张伟平二手车 ak

Analysis of a Simple Probe for <i>In-Situ</i>Resistivity Measurements

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Journal of Water Resource and Protection 2017年第1期9卷 1-10页

作者： Jens Munk Todd Petersen Matt Cullin William Schnabel Department of Electrical Engineering University of Alaska Anchorage Anchorage AK USA Department of Mechanical Engineering University of Alaska Anchorage Anchorage AK USA University of Alaska Fairbanks Fairbanks AK USA

We present a probe factor for a simple measurement device, which can be used to determine in-situ electrical resistivity in soils or other penetrable bodies. The probe is primarily sensitive to the material immediately surrounding it and therefore is ideal for determining localized conductivities. The geometry of the probe can be scaled to effectively adjust the region of interest. The calibration, or “probe factor” is a function of the geometry, as well as the electrode configuration. Results are presented assuming a Wenner array configuration, however they can easily be extended to other geometries, such as the Schlumberger or dipole-dipole array.

关键词： Electrical Resistivity Measurements Soil Moisture Electrical Conductivity Geophysical Measurement

Kuo-Hua Sun:The founder of physiologic psychology and child psychology in China

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Protein & Cell 2021年第8期12卷 593-595页

作者： Yimeng Wang Yanyan Qian School of Psychology Nanjing Normal UniversityNanjing 210097China Social and Behavioral Sciences Facility Leiden University2333AK LeidenThe Netherlands

Kuo-Hua Sun(孙国华,1902-1958,courtesy name—Xiao Meng)(Fig.1)was a Chinese psychologist mainly engaged in Physiological Psychology and Child ***-Hua Sun was born on March 6th,1902,in Weixian,Shandong *** studied in Tsinghua School from 1914 to *** the same year,Sun attended the education school of Ohio State University,and then received a Bachelor of Psychology(1928)and a Doctor of Philosophy(1929)from Ohio State *** this period,Sun studied in the Department of Physiology at Chicago University(1925-1926)(Fig.2).

关键词：孙国华 Chicago education

Obtaining the best possible predictions of habitat selection for wintering Great Bustards in Cangzhou, Hebei Province with rapid machine learning analysis

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Chinese Science Bulletin 2014年第32期59卷 4323-4331页

作者： Chunrong Mi Falk Huettmann Yumin Guo College of Nature Conservation Beijing Forestry University EWHALE Laboratory Department of Biology and WildlifeInstitute of Arctic Biology University of Alaska Fairbanks Biology Fairbanks AK 99775 USA

Great Bustards(Otis tarda dybowskii)are one of the world’s heaviest flying birds,occupying grassland habitats in Eastern *** study is located at the most eastern Chinese wintering site in Cangzhou,Hebei Province,where approximately 100 individuals are concentrated in a small area(17.53 km2).Solid information is still lacking about the wintering areas for this subspecies in its eastern range and specifically for *** study area consists of intensely used farmland in proximity to humans and is lacking conservation areas and wild,open ***,we present our results from two years of field data collection on habitat *** choose a machine learning model approach based on a rapid assessment methodology for the winter habitat of the Great *** is based on a spatial analysis of the best available environmental data,which were collected relatively *** relatively new methods in ecology are based on an ensemble of decision trees and include algorithms such as TreeNet,Random Forest and CART used in *** this study,we collected bustard droppings(presence only)from 48 locations between December 2011 and January 2012 and used the sites as training *** from 23 locations were collected in November 2012,and those sites were used as test *** used eight environmental variables as predictor layers for the response variable of bustard presence/*** employed a Geographic Information System(ArcGIS 10.1and Geospatial Modelling Environment)and Google *** with the other three models,we found that predictions from Random Forest obtained a significant difference between presence and *** to this model,the three most important factors for wintering Great Bustards are distance to residential area,distance to water pools,and farmland *** model shows that wintering Great Bustards prefer locations that are over 400 m away from residential areas,within 900 m of water pools and on areas of farmland smal

关键词：河北省沧州市栖息地选择机器学习越冬地大鸨预测地理信息系统野外数据采集

Climatology of Air Quality in Arctic Cities—Inventory and Assessment

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Open Journal of Air Pollution 2018年第1期7卷 48-93页

作者： Nicole Molders Gerhard Kramm Department of Atmospheric Sciences Geophysical InstituteUniversity of Alaska FairbanksFairbanksAKUSA Engineering-Meteorology-Consulting FairbanksAKUSA

Freely available data of sulfur dioxide (SO2), ammonia (NH3), nitrogen dioxide (NO2), ozone (O3), and particulate matter (PM) observed in Arctic cities (north of 59.99 N) between 1972 and 2016 were compiled into an air-quality inventory of samples taken for limited periods. For cities with multiple years of data, air-quality climatology was determined in terms of daily means in the annual course. Mean urban air-quality climatology was calculated for regions of similar insolation, emission standards, topography, Köppen-Geiger classification, and city size. Urban concentrations of PM precursors (SO2, NH3, NO2), PM2.5 and PM10 (PM with diameter less than 2.5 and 10 μm) were assessed in the sense of climatology with evidence from current knowledge. Typically, annual SO2 and NO2 means were lower for small than large Arctic cities, but can vary more than an order of magnitude over short distance. Cities seeing seasonal sea-ice had W-shaped mean annual courses of daily O3, while other cities had a spring maximum. Typically, annual means of urban pollutants in North America exceeded those in Scandinavia except for O3, where the opposite was true. Annual mean urban PM2.5 and PM10 concentrations varied from 1.6 to 21.2 μg·m-3 and 2 to 18.2 μg·m-3, respectively. Since PM10 encompasses PM2.5, annual PM10 means must be at least 21.2 μg·m-3. According to rural-to-urban ratios of species, seasonal transport of pollutants from wildfires, shipping, and the Kola Peninsula mining area occurred at some sites in Interior Alaska, western and northern Norway, respectively. Concurrent SO2 and PM or NO2 and PM measurements revealed combustion or traffic as major contributors to urban concentrations. Recommendations for potential future measurements of Arctic urban air quality were given based on the assessments of climatology and inventory.

关键词： Air Pollution in Arctic Cities Urban Air Quality in the Arctic Air-Quality Climatology in the Arctic Arctic Air-Quality Inventory Arctic Cities

土壤的冷生构造及其对阿拉斯加土地利用的意义(英文)

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冰川冻土 2004年第S1期26卷 1-7页

作者： C.L Ping M.T. Jorgeson Y.L. Shur Agricultural and Forestry Experiment Station University of Alaska Fairbanks Palmer AK 99645 USAABR Inc. Fairbanks AK USADepartment of Civil and Environmental Engineering University of Alaska Fairbanks Fairbanks AK USA

Cryogenic structure (patterns made by ice inclusions) in seasonally frozen and permafrost-affected soils result from ice formation during freezing. Analysis of cryogenic structures in soils is essential to our understanding of the cryogenic processes in soils and to formulating land use management interpretations. When soils freeze, the freezing front moves downward and attracts water moving upward resulting in mainly horizontal lenticular ice formation. Platy and lenticular soil structures form between ice lenses in upper active layer. The reticular soil structure usually forms above the permafrost table caused by freeze-back of the permafrost. The upward freeze-back resulted in platy soil structure and the volume changes following the annual freeze-thaw cycle resulted in vertical cracks. The combined result is an ice-net formation with mineral soils embedded in the ice net. The upper permafrost layer that used to be a part of the active layer has an ice content exceeding 50% due to repeated freeze-thaw cycles over time. The mineral soils appear in blocks embedded in an ice matrix. The permafrost layer that never experienced the freeze-thaw cycle often consists of alternate layers of thin ice lens and frozen soils with extreme hard consistence and has relatively lower ice content than the ice-rich layer of the upper permafrost. Ice contents and thaw settling potentials associated with each cryogenic structure should be considered in engineering and land use interpretations.

关键词： cryogenic structure cryogenic processes in soils ice layer land use Alaska

Near-field surface displacement and permanent deformation induced by the Alaska Mw 7.5 earthquake determined by high-rate real-time ambiguity-fixed PPP solutions

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Chinese Science Bulletin 2014年第34期59卷 4781-4789页

作者： Gang Chen Qile Zhao Faculty of Information Engineering Department of Surveying Engineering China University of Geosciences Geophysical Institute University of Alaska FairbanksFairbanks AK 99775-7320 USA GNSS Research Center Wuhan University

High-rate GPS data from the United States continuously operating reference stations in the Alaska region are processed using the recently developed precise point positioning(PPP) technique. The traditional PPP technique does not fix ambiguities into their integers because these ambiguities do not have an integer nature when data from a single receiver, as well as precise orbit and clock corrections, are used. Additional corrections, i.e.,uncalibrated phase delay(UPD), are needed to fix integer ambiguities and consequently improve positioning accuracy. This study proposes a methodology to compute for wide-lane and L2(the second L-band frequency) UPDs using the geometry-based model and subsequently applies these parameters to the computation for ambiguity-fixed solutions. The instantaneous displacements of near-field sites, as well as the permanent deformations after the earthquake, are therefore obtained for the January 5, 2013,Alaska earthquake. The real-time performance of PPP solutions are assessed by considering realistic data latency and data interval of corrections. Ambiguity-fixed solutions are compared with ambiguity-float ones. The comparison shows that the positioning accuracy can be improved significantly when the ambiguities are fixed correctly. Thesolutions using the real-time corrections are also compared with those using post-processing corrections, i.e., Center for Orbit Determination in Europe final orbit and *** the accuracy is somehow degraded because of the data latency and data interval, the real-time results are satisfactory for use in monitoring the small-scale deformation(1–2 cm) caused by the Alaska earthquake. In addition, the kinematic ambiguity-fixed PPP solutions for7 days around the earthquake are calculated to obtain permanent pre- and post-earthquake deformations. The deformations computed from real-time and post-processing corrections do not appear to be significantly different.

关键词：整数模糊度永久变形阿拉斯加实时性能地表位移 PPP 地震后近场