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Galaxy formation in the reionization epoch as hinted by WideField Camera 3 observations of the Hubble Ultra Deep Field

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Research in Astronomy and Astrophysics 2010年第9期10卷 867-904页

作者： Hao-Jing Yan Rogier A. Windhorst Nimish E Hathi Seth H. Cohen Russell E.Ryan Robert W. o＇Connell Patrick J. McCarthy Center for Cosmology and AstroParticle Physics The Ohio State University 191 West Woodruff Avenue Columbus OH 43210 USA School of Earth and Space Exploration Arizona State University Tempe AZ 85287 USA Department of Physics ＆ Astronomy University of California Riverside CA 92521 USA Department of Physics University of California One Shields Avenue Davis CA 95616 USA Astronomy Department University of Virginia P.O. Box 3818 Charlottesville VA 22903 USA observatories of the Carnegie Institution of Washington 813 Santa Barbara Street Pasadena CA 91101 USA

We present a large sample of candidate galaxies at z ≈ 7 - 10, selected in the Hubble Ultra Deep Field using the new observations of the Wide Field Camera 3 that was recently installed on the Hubble Space Telescope. our sample is composed of 20 z850-dropouts （four new discoveries）, 15 Y105-dropouts （nine new discoveries） and 20 J125-dropouts （all new discoveries）. The surface densities of the Z850-dropouts are close to what was predicted by earlier studies, however, those of the Y105- and J125-dropouts are quite unexpected. While no Y105- or J125-dropouts have been found at AB ≤ 28.0 mag, their surface densities seem to increase sharply at fainter levels. While some of these candidates seem to be close to foreground galaxies and thus could possibly be gravitationally lensed, the overall surface densities after excluding such cases are still much higher than what would be expected if the luminosity function does not evolve from z ～ 7 to 10. Motivated by such steep increases, we tentatively propose a set of Schechter function parameters to describe the luminosity functions at z ≈8 and 10. As compared to their counterpart at z ≈ 7, here L^＊ decreases by a factor of ～ 6.5 and Ф^＊ increases by a factor of 17-90. Although such parameters are not yet demanded by the existing observations, they are allowed and seem to agree with the data better than other alternatives. If these luminosity functions are still valid beyond our current detection limit, this would imply a sudden emergence of a large number of low-luminosity galaxies when looking back in time to z ≈ 10, which, while seemingly exotic, would naturally fit in the picture of the cosmic hydrogen reionization. These early galaxies could easily account for the ionizing photon budget required by the reionization, and they would imply that the global star formation rate density might start from a very high value at z ≈ 10, rapidly reach the minimum at z≈ 7, and start to rise again towards z ≈ 6. In this scenario, the maj

关键词： cosmology observations -- cosmology early universe -- galaxies evolution -- galaxies luminosity function, mass function -- infrared galaxies

Leaching and Redistribution of Nutrients in Surface Layer of Red Soils in Southeast China

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Pedosphere 2000年第2期10卷 135-142页

作者： SUN Bo ZHANG TAoLIN and ZHAo QIGUo(Institute of Soil Science, the Chinese Academy of Sciences, P.o. Box 821, Naniing 210008 China) 中科院南京土壤所江苏南京 210008

The leaching and redistribution of nutrients in the surface layer of 4 types of red soils in SoutheastChina were studied with a lysimeter experiment under field conditions. Results showed that the leachingconcentrated in the rainy season (from April to June). Generaily, the leaching of soil nutrients from thesurface layer of red soils was in the order of Ca > Mg > K > No3-N. In fertilization treatment, the totalamount of soil nutrients leached out of the surface layer in a red soil derived from granite was the highest inall soils. The uptake by grass decreased the leaching of fertilizer ions in surface layer, particularly for *** total N and exchangeable K, Ca and Mg in the surface layer decreased with leaching and grass uptakeduring the 2 years without new fertilization of urea, Ca(H2Po4)2, KCl, CaCo3 and MgCo3. Ca movedfrom the application layer (0~5 cm) of fertilizer and accumulated in the 10~30 cm depth in the soils studiedexcept that derived from Quaternary red clay. The deficiency of soil exchangeable K will become a seriousdegradation process facing the Southeast China.

关键词： leaching nutrients red soils redistribution Southeast China

Mitochondrial phylogeography and molecular evolution of the rhodopsin visual pigment in troglobitic populations of Astyanax mexicanus(De Filippi,1853)

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Zoological Research 2023年第4期44卷 761-775页

作者： Marco A.A.Garduño-Sánchez Vladimir de Jesus-Bonilla Silvia Perea Ramses Miranda-Gamboa Andrea Herrera-García Mauricio de la Maza Benignos Claudia Patricia ornelas-García Colección Nacional de Peces Departamento de ZoologíaInstituto de BiologíaUniversidad Nacional Autónoma de MéxicoCiudad de MéxicoC.P.04510México Posgrado en Ciencias Biológicas Colección Nacional de PecesDepartamento de ZoologíaInstituto de BiologíaUniversidad Nacional Autónoma de MéxicoCiudad de MéxicoC.P.04510México Licenciatura en Ciencias Forenses Facultad de MedicinaUniversidad Nacional Autónoma de MéxicoCiudad UniversitariaCoyoacánMéxico CityC.P.04510México Instituto de Energías Renovables Universidad Nacional Autónoma de MéxicoTemixcoMorelos C.P.62580Mexico Facultad de Ciencias Biológicas Universidad Autónoma de Nuevo LeónCiudad UniversitariaSan Nicolás de los GarzaNuevo LeónC.P.66450México

Cave-adapted animals provide a unique opportunity to study the evolutionary mechanisms underlying phenotypic,metabolic,behavioral,and genetic evolution in response to cave *** Mexican tetra(Astyanax mexicanus)is considered a unique model system as it shows both surface and cave-dwelling *** date,at least 33 different cave populations have been identified,with phylogenetic studies suggesting an origin from at least two independent surface lineages,thereby providing a unique opportunity to study parallel *** the present study,we carried out the most exhaustive phylogeographic study of *** to date,including cave and surface localities,using two mitochondrial markers(cytochrome b(cyt b)and cytochrome c oxidase subunit I(CoI))and nuclear rhodopsin visual pigment(rho).Additionally,we inferred the molecular evolution of rho within the two contrasting environments(cave and surface)and across three geographic regions(Sierra de El Abra,Sierra de Guatemala,and Micos).In total,267 individuals were sequenced for the two mitochondrial fragments and 268 individuals were sequenced for the rho visual pigment from 22 cave and 46 surface *** results based on the mitochondrial data supported the two-lineage hypothesis,except for the Pachón and Chica caves,whose introgression has been largely *** Sierra de El Abra region depicted the largest genetic diversity,followed by the Sierra de Guatemala *** the phylogeographic patterns of rho,we recovered exclusive haplogroups for the Sierra de El Abra(Haplogroup I)and Sierra de Guatemala regions(Haplogroup IV).Moreover,a 544 bp deletion in the rho gene was observed in the Escondido cave population from Sierra de Guatemala,reducing the protein from seven to three intramembrane *** change may produce a loss-of-function(LoF)but requires further *** nonsynonymous(dN)and synonymous(dS)substitution rates(omega valuesω),our results revealed

关键词： Visual pigments Selection Cavefish Vision loss Loss of function

How Safe Are America's Schools?

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英语学习 1999年第2期 7-8页

作者： Kelly o'Donnell 刘相东

美国的中、小学校暴力事件层出不穷,很让教育专家、教师和学生家长头痛。有没有治疗学校暴力的良方?An issue front and center at the white house

关键词：宾语从句过去分词 How Safe Are America’s Schools

Review of deep learning and artificial intelligence models in fetal brain magnetic resonance imaging

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World Journal of Clinical Cases 2023年第16期11卷 3725-3735页

作者： Farzan Vahedifard Jubril o Adepoju Mark Supanich Hua Asher Ai Xuchu Liu Mehmet Kocak Kranthi K Marathu Sharon E Byrd Department of Diagnostic Radiology and Nuclear Medicine Rush Medical CollegeChicagoIL 606012United States Division for Diagnostic Medical Physics Department of Radiology and Nuclear MedicineRush University Medical CenterChicagoIL 606012United States

Central nervous system abnormalities in fetuses are fairly common,happening in 0.1%to 0.2%of live births and in 3%to 6%of *** initial detection and categorization of fetal Brain abnormalities are *** detecting and segmenting fetal brain magnetic resonance imaging(MRI)could be timeconsuming,and susceptible to interpreter *** intelligence(AI)algorithms and machine learning approaches have a high potential for assisting in the early detection of these problems,improving the diagnosis process and follow-up *** use of AI and machine learning techniques in fetal brain MRI was the subject of this narrative review *** AI,anatomic fetal brain MRI processing has investigated models to predict specific landmarks and segmentation *** gestation age weeks(17-38 wk)and different AI models(mainly Convolutional Neural Network and U-Net)have been *** models'accuracy achieved 95%and *** could help preprocess and postprocess fetal images and reconstruct ***,AI can be used for gestational age prediction(with one-week accuracy),fetal brain extraction,fetal brain segmentation,and placenta *** fetal brain linear measurements,such as Cerebral and Bone Biparietal Diameter,have been *** of brain pathology was studied using diagonal quadratic discriminates analysis,Knearest neighbor,random forest,naive Bayes,and radial basis function neural network *** learning methods will become more powerful as more large-scale,labeled datasets become *** shared fetal brain MRI datasets is crucial because there aren not many fetal brain pictures ***,physicians should be aware of AI's function in fetal brain MRI,particularly neuroradiologists,general radiologists,and perinatologists.

关键词： Artificial intelligence Fetal brain Magnetic resonance imaging Neuroimaging

Analysis of Growth and Productivity of Green Chickpea Using Nitrogen and Phosphorus Fertilization

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Phyton-International Journal of Experimental Botany 2021年第4期90卷 1193-1203页

作者： Maricela Apáez-Barrios JoséAlberto Salvador Escalante-Estrada Patricio Apáez-Barrios Yurixhi Atenea Raya-Montaño Juan CarlosÁlvarez-Hernández Facultad de Ciencias Agropecuarias-Universidad Michoacana de San Nicolás de Hidalgo Apatzingán60670México Colegio de Postgraduados-Campus Montecillo Texcoco56230México Facultad de Agrobiología“Presidente Juárez” Universidad Michoacana de San Nicolás de HidalgoUruapan60190México

Chickpea contains high levels of protein,vitamins and *** chickpea yield is the result of meeting nitrogen and phosphorus *** effect of appropriately meeting such requirements reflects on growth and can easily be evaluated using growth *** research determined:(a)The effect of nitrogen and phosphorus fertilization on phenology,net assimilation rate,number of green leaves,leaf area,leaf area index and leaf area duration;(b)Green chickpea yield and number of pods due to fertilization;and(c)The combination of nitrogen and phosphorus fertilization that yields the most net *** and phosphorus fertilization was evaluated;each at the doses of 0,75 and 150 kg ha–1(N0,N75,N150;P0,P75 and P150,respectively).The combination of the levels of both nutrients generated nine combinations of treatments which were distributed in the field in a randomized complete block design in an arrangement of divided plots with four *** of phenological phases were similar among *** and phosphorus fertilization increased number of leaves,leaf area index,and leaf area duration that translated into increased green chickpea yield(GCY).Combinations N150-P75 and N150-P150 produced the highest *** highest net revenue and revenue per peso invested was obtained with N150-P75.

关键词： Cicer arietinum economic analysis leaf area number of leaves yield

The Last Leaf(continued)

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大学英语 1984年第5期 24-25页

作者： o.Henry 杨芳林

PART ⅡSue found Behrman in his poorly-lighted studio. In one corner ofthe room stood a blank canvas which had been waiting for twenty-fiveyears to receive the first line of the promised masterpiece. Sue told himof th... 详细信息

关键词： continued The Last Leaf

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The Last Leaf

大学英语 1984年第4期 21-24页

作者： o.Henry 杨芳林

PART ⅠMany people who areintetested in art cometo Greenwich Village,which is a section of NewYork City. They like thebohemian life of the vil-lage, and they enjoy livingamong so many *** buildings and apart-ments are... 详细信息

关键词： The Last Leaf

Effect of Sulphur in Rainfall, Irrigation Waterand Perco colating Water on Soil Sulphur in Jiangxi Province

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Pedosphere 2000年第2期10卷 177-182页

作者： LIU CHoNGQUN CAo SHUQING and XU JUNXIANG(Institute of Soil Science, the Chinese Academy of Sciences, P.o. Box 821, Narolng 210008 China) 中科院南京土壤所江苏南京 210008

Ten rainfall and irrigation water-collecting posts were set up in different ecotype districts of JiangxiProvince, China, to quarterly measure S content in rainfall and irrigation water. A rainwater chemicalcomposition- collecting device was used to collect the sulphur in rainfall land the amount of sulphur adsorbedon the resin column in the device was determined. The soil percolating water was gathered using 6 lysimeters,built up according to the profile sequence of the red soil derived from red sandstone and the red soil derivedfrom Quaternary red clay, separately. on the lysimeters peanuts, soybean and radish were grown in *** treatments were designed: without S addition and with S addition at a rate of 14 kg S ha-1. The So24contents in rainfall, irrigation water and soil percolating water were determined by the *** results in 1997 showed that the average annual S content in rainwater was 28.13 kg S ha-1, theaverage S content in irrigation water was 1.7 mg S L-1 , and the average content of in soil percolationwater was 2.30 kg S ha-1 year-1 and 4.70 kg S ha-l year-1 in treatments without and with sulphurapplication, respectively. In Jiangxi Province, apart from the losses by runoff and leaching, the sulphur inrainfall available to crops is 7.3 kg S ha-1 year-1 and additional S application is required. When rice isgrown , however, irrigation water can supply 6.9 kg S ha-1, which, along with the sulphur in rainfall, canalmost meet the S requirement of one cropping of rice.

关键词： irrigation water Jiangxi Province rainfall soil percolation water sulphur