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Events and reaction m.chanism. during the synthesis of an AI2O3-TiB2 nanocom.osite via high energy ball m.lling

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Frontiers of Chem.cal Science and Engineering 2013年第2期7卷 123-129页

作者： m. ABDELLAHI m. ZAKERI H. BAHm.NPOUR m.terials Engineering Departm.nt Islamic Azad University Saveh Branch Saveh Iran Ceram.c Departm.nt Materials and Energy Research Center Tehran 31787/316 Iran Chem.cal engineering and m.terials Science Departm.nt University of California Davis CA 95616 USA

An AI2O3-TiB2 nanocom.osite was success- fully synthesized by the high energy ball m.lling of A1, B2O3 and TiO2. The structures of the powdered particles form.d at different m.lling tim.s were evaluated by X-ray diffraction （XRD）, scanning electron m.croscopy （SEm. and transm.ssion electron m.croscopy （TEm.. Therm.- dynam.c calculations showed that the com.osite form.d in two steps via highly exotherm.c m.chanically induced self-sustaining reactions （m.Rs）. The com.osite started to form.at m.lling tim.s of 9-10 h but the reaction was not com.lete. The rem.ining starting m.terials were consum.d by increasing the m.lling tim. to 15 h. The XRD patterns of the annealed powders showed that alum.num.borate is one of the interm.diate products and that it is consum.d at higher tem.eratures. Heat treatm.nt of the 6-h m.lled sam.le at l l00℃ led to a com.lete form.tion of the com.osite. Increasing the m.lling tim. to 15 h led to a refining of the crystallite sizes. A nanocom.osite powder with a m.an crystallite size of 35-40 nm.was obtained after m.lling for 15 h.

关键词： ball m.lling nanocom.osite AI2O3 TiB2

SubEpiPredict:A tutorial-based prim.r and toolbox for fitting and forecasting growth trajectories using the ensem.le n-sub-epidem.c m.deling fram.work

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Infectious Disease m.delling 2024年第2期9卷 411-436页

作者： Gerardo Chowell Sushm. Dahal Am.nda Bleichrodt Am.a Tariq Jam.s m.Hym.n Ruiyan Luo Departm.nt of Population Health Sciences School of Public HealthGeorgia State UniversityAtlantaGAUSA Departm.nt of International Epidem.ology and Population Studies Fogarty International CenterNational Institutes of HealthBethesdaMDUSA Departm.nt of Pediatrics School of MedicineStanford UniversityPalo AltoCAUSA Departm.nt of m.them.tics Center for Computational ScienceTulane UniversityNew OrleansLAUSA

An ensem.le n-sub-epidem.c m.deling fram.work that integrates sub-epidem.cs to capture com.lex tem.oral dynam.cs has dem.nstrated powerful forecasting capability in previous *** m.deling fram.work can characterize com.lex epidem.c patterns,including plateaus,epidem.c resurgences,and epidem.c waves characterized by m.ltiple peaks of different *** this tutorial paper,we introduce and illustrate SubEpiPredict,a user-friendly m.TLAB toolbox for fitting and forecasting tim. series data using an ensem.le n-sub-epidem.c m.deling *** toolbox can be used for m.del fitting,forecasting,and evaluation of m.del perform.nce of the calibration and forecasting periods using m.trics such as the weighted interval score(WIS).We also provide a detailed description of these m.thods including the concept of the n-sub-epidem.c m.del,constructing ensem.le forecasts from.the top-ranking m.dels,*** the illustration of the toolbox,we utilize publicly available daily COVID-19 death data at the national level for the United *** m.TLAB toolbox introduced in this paper can be very useful for a wider group of audiences,including policym.kers,and can be easily utilized by those without extensive coding and m.deling backgrounds.

关键词： n-Sub-epidem.c m.del Forecasting m.TLAB Sub-epidem.cs Phenom.nological m.dels Perform.nce m.trics m.del evaluation

carbon Nanotube Based Chem.cal Sensors

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稀有金属材料与工程 2006年第A3期35卷 7-8页

作者： m. m.yyappan Center for Nanotechnology NASA Ames Research Center Mailtstop 229-3Moffett FieldCA 94035USA

carbon nanotubes CNTs)have been receiving enorm.us attention in the last decade due to their extraordinary m.chanical properties and unique elec- tronic *** com.ination has produced an unprecedented range of applications for CNTs:elec- tronic,logic and m.m.ry chips,chem.cal and biosen- sots,com.osites,lithium.batteries,gas storage,filters and m.m.ranes,*** presentation will focus on carbon nanotube based sensors and discuss fabrication, testing and perform.nce.

关键词： SWNTs CNTs carbon Nanotube Based Chem.cal Sensors

Telom.ric DNA breaks in hum.n induced pluripotent stem.cells trigger ATR-m.diated arrest and telom.rase-independent telom.re dam.ge repair

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Journal of m.lecular Cell Biology 2024年第3期16卷 46-60页

作者： Katrina N.Estep John W.Tobias Rafael J.Fernandez Brinley m.Beveridge F.Brad Johnson Departm.nt of Pathology and Laboratory m.dicine University of PennsylvaniaPhiladelphiaPA 19104USA Quantiative Biosciences Merck&Co.Inc.West PointPA 19486USA Penn Genom.c Analysis Core University of PennsylvaniaPhiladelphiaPA 19104USA

Although m.chanism. of telom.re protection are well-defined in differentiated cells,how stem.cells sense and respond to telom.re dysfunction,in particular telom.ric double-strand breaks(DSBs),is poorly ***,we report the DNA dam.ge signaling,cell cycle,and transcriptom. changes in hum.n induced pluripotent stem.cells(iPSCs)in response to telom.re-internal *** engineer hum.n iPSCs with an inducible TRF1-FokI fusion protein to acutely induce DSBs at *** this m.del,we dem.nstrate that TRF1-FokI DSBs activate an ATR-dependent DNA dam.ge response,which leads to p53-independent cell cycle arrest in *** CRISPR–cas9 to cripple the catalytic dom.in of telom.rase reverse transcriptase,we show that telom.rase is largely dispensable for survival and lengthening of TRF1-FokI-cleaved telom.res,which instead are effectively repaired by robust hom.logous recom.ination(HR).In contrast to HR-based telom.re m.intenance in m.use em.ryonic stem.cells,where HR causes ZScaN4-dependent extension of telom.res beyond their initial lengths,HR-based repair of telom.ric breaks is sufficient to m.intain iPSC telom.res at a norm.l length,which is com.atible with sustained survival of the cells over several days of TRF1-FokI *** findings suggest a previously unappreciated role for HR in telom.re m.intenance in telom.rase-positive iPSCs and reveal distinct iPSC-specific responses to targeted telom.ric DNA dam.ge.

关键词： telom.res telom.rase alternative lengthening of telom.res pluripotent stem.cells DNA dam.ge double-strand breaks

Analysis and m.deling of Slope Stability in the Three-Gorges Dam.Reservoir (China)——The case of Huangtupo Landslide

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Journal of m.untain Science 2011年第2期8卷 166-175页

作者： R.COJEAN Y.J.ca Centre de Géosciences Mines-ParisTech Paris France Changjiang Institute of Survey Planning Design & Research CWRC Wuhan China

The water level in the Three Gorges Dam.reservoir is expected to change between the elevations of 145 m.and 175 m. as a function of the flood control im.lem.ntation and the intensity of the annual flood. As a m.tter of fact, the hydraulical and m.chanical loadings, related to the water level m.difications, will result in alterations in the slope stability conditions. The town of Badong (Hubei), of 20 000 inhabitants, is one of the towns which was subm.rged by the im.oundm.nt of the reservoir. As a consequence, the new town of Badong was constructed on a nearby site which appeared to be partly an unstable site. A part of this site corresponds to an old landslide, the Huangtupo landslide, the base of which had to be subm.rged by the water of the reservoir. The analysis of the Huangtupo landslide, taking into account various events scenarios, drainage and reinforcem.nt m.asures and m.nitoring devices, allows to illustrate the general process im.lem.nted all along the reservoir in order to m.tigate the landslide hazard.

关键词： Three Gorges Dam Landslide m.delling

Genetic Variability and Phenotypic Correlations Study am.ng Grain Quality Traits and m.neral Elem.nts Concentrations in Colored and Non-Colored Rice (Oryza sativa L.)

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Phyton-International Journal of Experim.ntal Botany 2024年第7期93卷 1733-1748页

作者： Adel A.Rezk m.ham.d m.El-m.lky Heba I.m.ham.d Hossam.S.El-Beltagi Agricultural Biotechnology Departm.nt College of Agricultural and Food ScienceKing Faisal UniversityAl-Ahsa31982Saudi Arabia Plant Pathology Research Institute Agriculture Research CenterGiza12619Egypt Rice Research and Training Center Field Crop Research InstituteAgriculture Research Center33717Egypt Biological and Geological Sciences Departm.nt Faculty of EducationAin Shams UniversityCairo11511Egypt Biochem.stry Departm.nt Faculty of AgricultureCairo UniversityGiza12613Egypt

Twenty-four rice genotypes were exam.ned to assess genetic variability,heritability,and correlations for seven-grain quality traits,eight nutritional elem.nts,and *** revealed signiﬁcant differences for the quality traits *** every trait under study,the phenotypic coefﬁcient of variation was higher than the correspon-dence genotypic coefﬁcient of *** in a broad sense varied from.29.75%for grain length to 98.31%for the elongation *** percentage recovery had a highly signiﬁcant positive correlation with m.lling and head rice ***,m.lling percentage had a highly positive correlation with head rice *** am.lose percentage,all the genotypes belonged to low am.lose except the Hassawi-1 variety,which had interm.diate am.lose *** nutrition contents of m.gnesium.m.),sodium.Na),potas-sium.K),calcium.ca),copper(Cu),m.nganese(m.),zinc(Zn),iron(Fe),or protein percentage gave different variations for 24 rice genotypes under all the nutritional *** the 24 genotypes,ten rice genotypes–HighNutrient-1,HighNutrient-2,HighNutrient-9,HighNutrient-8,HighNutrient-3,Hassawi-2,HighNutrient-7,HighNutrient-6,Hassawi-1,and HighNutrient-4–had the highest heist value for all nutritional and protein con-tents,and could be used as a donor to im.roving new *** was a positive and signiﬁcant correlation between m.gnesium.m.,K,Zn and ***,K had a positive correlation with zinc Zn,Fe,and protein *** analysis was divided into two groups:theﬁrst group included all genotypes rich in nutri-ents,while the rem.ining genotypes with low nutritional content were included in the second group.

关键词： Am.lose cluster analysis genotypes grain quality m.neral nutrition rice

Scientific observations at total solar eclipses

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Research in Astronom. and Astrophysics 2009年第6期9卷 613-634页

作者： Jay m. Pasachoff William. College-Hopkins Observatory Williamstown Massachusetts 01267 USA california Institute of Technology 150-21 Pasadena CA 91125

The occasion of the longest totality of an eclipse in the 18 yr 11^1/3 d saros cycle leads to taking stock of the scientific value of ground-based eclipse observations in this space age. Though a num.er of space satellites from.the U.S., Europe, Japan, and Russia study the Sun, scientists at eclipses can observe the solar chrom.sphere and corona at higher spatial resolution, at higher tem.oral resolution, and at higher spectral resolution than are possible aloft. Furtherm.re, eclipse expeditions can transport a wide variety of state-of-the-art equipm.nt to the path of totality. Thus, for at least som. years to com., solar eclipse observations will rem.in both scientifically valuable and cost-effective ways to study the outer solar atm.sphere.

关键词： Sun eclipses

The size effect on transport properties of colossal m.gnetoresistance m.terials La_(0.67)ca_(0.33)m.O_3

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Science China(Physics,m.chanics & Astronom.) 2008年第3期51卷 251-257页

作者： LI PeiGang1,2,LEI m.ng1,2,GUO YanFeng2,GUO Xi2,CHEN Leim.ng2, TANG WeiHua1,2,SONG PengYun3 & CHEN JinPing3 1 Departm.nt of Physics,Center for Optoelectronics m.terials and Devices,Zhejiang Sci-Tech University,Hangzhou 310018,China 2 National Laboratory for Condensed m.tter Physics,Institute of Physics,Chinese Academ. of Sciences,Beijing 100080,China 3 Departm.nt of Physics,Peking University,Beijing 100875,China 1. Departm.nt of Physics Center for Optoelectronics Materials and Devices Zhejiang Sci-Tech University Hangzhou 310018 China 2. National Laboratory for Condensed m.tter Physics Institute of Physics Chinese Academy of Sciences Beijing 100080 China 3. Departm.nt of Physics Peking University Beijing 100875 China

High quality La0.67ca0.33m.O3 (LCm.) film.was deposited via a novel pulsed electron deposition technique on SrTiO3(100) single crystal substrate. The m.cro-bridge with different widths was fabricated by using electron beam.lithography (EBL) technique and their transport properties were studied. For the m.cro-bridges with width of 2 and 1.5 μm.the insulator-to-m.tal transition tem.erature (TP) keeps un-changed com.ared with the film. For the m.cro-bridges with width of 1 μm.the TP shifts towards the lower tem.erature by 50 K. When the width decreases down to 500 nm.the insulator-to-m.tal transition disappears. The m.gnetoresistance be-havior of these m.cro-bridges was studied,and the results show that the low field m.gnetoresistance (LFm.) decreases and the high field m.gnetoresistances (HFm.) keep alm.st unchanged as the width of m.cro-bridge is reduced.

关键词： colossal m.gnetoresistance pulsed electron deposition electron beam lithography electrical transport properties

The Clock Protein Cca1 and the bZIP Transcription Factor HY5 Physically Interact to Regulate Gene Expression in Arabidopsis

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m.lecular Plant 2008年第1期1卷 58-67页

作者： Christos Andronis Sim.n Barak Stephen m. Knowles Shoji Sugano Elaine m. Tobin Departm.nt of m.lecular Cell and Developmental Biology University of California Los Angeles CA 90095-1606 USA

The circadian clock regulates the expression of an array of Arabidopsis genes such as those encoding the LIGHT-Ha.vesTING CHLOROPHYLL A/B （Lhcb） proteins. We have previously studied the prom.ters of two of these Arabidopsis genes-Lhcb1＊1 and Lhcb1＊3m.and identified a sequence that binds the clock protein CIRcaDIAN CLOCK ASSOCIATED 1 （Cca1）. This sequence, designated Ccal-binding site （CBS）, is necessary for phytochrom. and circadian responsiveness of these genes. In close proxim.ty to this sequence, there exists a G-box core elem.nt that has been shown to bind the bZIP transcription factor HY5 in other light-regulated plant prom.ters. In the present study, we exam.ned the im.ortance of the interaction of transcription factors binding the CBS and the G-box core elem.nt in the control of norm.l circadian rhythm.c expression of Lhcb genes. Our results show that HY5 is able to specifically bind the G-box elem.nt in the Lhcb prom.ters and that Cca1 can alter the binding activity of HY5. We further show that Cca1 and HY5 can physically interact and that they can act synergistically on transcription in a yeast reporter gene assay. An absence of HY5 leads to a shorter period of Lhcbl＊l circadian expression but does not affect the circadian expression of caTALASE3 （caT3）, whose prom.ter lacks a G-box elem.nt. Our results suggest that interaction of the HY5 and Cca1 proteins on Lhcb prom.ters is necessary for norm.l circadian expression of the Lhcb genes.

关键词： Biorhythm. Basic-Leucine Zipper Transcription Factors Genes Transcription Factors Arabidopsis Cca1 gene CLOCK Proteins