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Increased Drying Rate Lowers the Critical water Content for Survival in Embryonic Axes of English Oak (Quercus robur L.) Seeds

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Journal of Integrative Plant Biology 2011年第4期53卷 270-280页

作者： Tobias M.Ntuli william E.Finch-Savage Patricia Berjak norman w.pammenter Plant Germplasm Conservation Research School of Biological and Conservation SciencesUniversity of KwaZulu-NatalWestville CampusPrivate Bag X54001Durban 4000South Africa Department of Life and Consumer Sciences University of South AfricaPrivate Bag X6Florida 1710JohannesburgSouth Africa warwick HRI Warwick UniversityWellesbourneWarwick CV35 9EFUK Plant Germplasm Conservation Research School of Biological and Conservation SciencesUniversity of KwaZulu-NatalWestville

The potential to cryopreserve embryonic axes of desiccation-sensitive（recalcitrant） seeds is limited by damage during the desiccation necessary for low temperature survival,but the basis of this injury and how to reduce it is not well *** effects of drying rate on the viability,respiratory metabolism and free radical-mediated processes were therefore investigated during dehydration of Quercus robur L embryonic ***,assessed by evidence of germination and tetrazolium staining,showed a sharp decline at 0.27 and 0.8 g/g during rapid（〈12 h） or slow（3d） dehydration,*** dehydration therefore lowered the critical water content for *** any given water content rapid dehydration was associated with higher activities of the free radical processing enzymes,superoxide dismutase,catalase and glutathione reductase and lower levels of hydroperoxide and membrane *** dehydration was also associated with lower malate dehydrogenase activity,and a reduced decline in phosphofructokinase activity and in levels of the oxidized form of nicotinamide *** may have contributed to increased damage during slow dehydration,since viability declined even in hydrated storage after 3 *** results presented are consistent with rapid dehydration reducing the accumulation of damage resulting from desiccation induced aqueous-based deleterious reactions.

关键词： Quercus robur L Seeds Figure NADH

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豌豆种子吸胀过程中脱水耐性变化的时间模式(英文)

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云南植物研究 2009年第3期31卷 239-246页

作者：宋松泉 Patricia BERJAK norman w.pammenter 中国科学院植物研究所北京100093 School of Biological and Conservation Sciences University of KwaZulu-Natal

研究了豌豆种子吸胀过程中脱水耐性的变化模式。种子在吸胀初期迅速吸收水分,然后缓慢吸收直到平台期。电解质渗漏速率在吸胀初期增加直到11h,然后随着吸胀下降。在吸胀过程中,种子的萌发率逐渐增加,种子和胚轴的脱水耐性逐渐丧失,10%和... 详细信息

研究了豌豆种子吸胀过程中脱水耐性的变化模式。种子在吸胀初期迅速吸收水分,然后缓慢吸收直到平台期。电解质渗漏速率在吸胀初期增加直到11h,然后随着吸胀下降。在吸胀过程中,种子的萌发率逐渐增加,种子和胚轴的脱水耐性逐渐丧失,10%和50%的种子和胚轴被脱水致死的含水量明显增加。赤霉素和脱落酸处理改变豌豆种子的萌发特性,提高胚轴的脱水耐性。研究结果表明,吸胀的豌豆种子脱水耐性的丧失是一种数量性状,正常性种子吸胀后脱水耐性的变化能够作为种子顽拗性研究的模式系统。

关键词：豌豆脱落酸脱水脱水耐性吸胀作用萌发正常性顽拗性

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Dehydration Kinetics of Embryonic Axes from Desiccation-sensitive Seeds:An Assessment of Descriptive Models

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Journal of Integrative Plant Biology 2009年第11期51卷 1002-1007页

作者： Tobias M. Ntuli norman w. pammenter School of Biological and Conservation Sciences University of KwaZulu-NatalWestville Campus

The response of desiccation-sensitive plant tissues to dehydration is significantly affected by dehydration conditions, particularly the rate of drying. Consequently it is important to be able to quantify drying rate. The aim of the study was to assess two models that have been proposed to describe drying kinetics, and thus to provide a quantification of non-linear drying rates, of embryonic axes excised from recalcitrant seeds. These models are an exponential drying time course, and a modified inverse relationship, respectively. For the six species investigated here the inverse function was generally found to fit drying data better than the exponential function under both rapid and slow drying conditions, and so is recommended. The rate of drying, under the conditions used here, was determined by axis size and possibly the nature of the axis outer coverings, rather than the water activity difference between the tissue and surrounding air.

关键词： desiccation drying rate recalcitrant seeds.

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A note on a boundary condition for spouted beds

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Particuology 2010年第6期8卷 536-538页

作者： norman Epstein Department of Chemical&Biological Engineering The University of British Columbia2216 Main MallVancouverB.C.Canada V6T 1Z3

The boundary condition, zero solids pressure at the top of a particle bed of maximum spoutable height, Hm, is shown to eliminate any resort to empiricism in the derivation of the fluid velocity in the annulus of a spouted bed for which both viscous and inertial effects are taken into account. The same boundary condition fails when applied to a spouted bed for which the bed height H 〈 Hm, especially when H 〈 0.8Hm.

关键词： Spouted beds Annulus flow Boundary condition Particle-fluid hydrodynamics

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Transitioning from paternalism to empowerment of farmers in lowincome countries: Farming components to systems

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Journal of Integrative Agriculture 2015年第8期14卷 1490-1499页

作者： David norman Agricultural Economics Department Kansas State University

Reasons for the initiation of farming systems/participatory approaches in non-Green Revolution（i.e., in more heterogeneous and less favourable production environments） areas in low-income countries is followed by a discussion of their *** phases are described along, with a brief description of some of the significant methods in which farmer participation has been sought, accessed and *** enabled/facilitated the evolutionary ***, over the last 40 years there has been a progress in making small-scale farmers much more visible in driving the agricultural research/development agenda through using the four basic stages embodied in the farming systems approach（i.e., descriptive, diagnosis, testing/evaluation and finally dissemination）, much still needs to be *** leads on to a discussion as to some of the barriers still inhibiting true farmer empowerment and why further, such empowerment is imperative, if the agricultural challenges of this century are to be addressed successfully, namely substantially increasing agricultural productivity in an ecologically sustainable *** the heterogeneity of the production environments and that many identified improvements are likely to be incremental rather than revolutionary in nature, this will require farmers＇ intimate involvement in their identification, evaluation and *** in the paper recognizes that there is increasing globalization/commercialization of agriculture and is predicated on the need to consider the whole farmer-research-development continuum involving multiple stakeholders（i.e., farmers, scientists, extension workers, input/output service providers and policymakers）.Such a continuum has been explicitly recognized in the operational plans for the recently reformed international agricultural research（i.e., CGIAR） *** paper concludes with a short discussion on the potential role of formal modelling.

关键词： farming systems research farmer empowerment farmer participatory approaches/techniques globalisation commercialisation conservat

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Speciation:genomic sequence data and the biogeography of speciation

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National Science Review 2022年第12期9卷 13-14页

作者： norman A.Johnson Department of Biology University of Massachusetts–Amherst

Two papers in this issue show how the use of genomic sequence data can illuminate the biogeography of the speciation ***,I provide a backdrop to these studies,with a brief history of the use of markers and the biogeog... 详细信息

关键词： Speciation:genomic sequence data and the biogeography of speciation

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Resistive Switching Memory of TiO2 Nanowire Networks Grown on Ti Foil by a Single Hydrothermal Method

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Nano-Micro Letters 2017年第2期9卷 23-31页

作者： Ming Xiao Kevin P.Musselman walter w.Duley norman Y.Zhou Centre for Advanced Materials Joining University of WaterlooWaterlooON N2L 3G1Canada waterloo Institute of Nanotechnology University of WaterlooWaterlooON N2L 3G1Canada Department of Mechanics and Mechatronics Engineering University of WaterlooWaterlooON N2L 3G1Canada Department of Physics and Astronomy University of WaterlooWaterlooON N2L 3G1Canada

The resistive switching characteristics of TiO_2 nanowire networks directly grown on Ti foil by a single-step hydrothermal technique are discussed in this paper. The Ti foil serves as the supply of Ti atoms for growth of the TiO_2 nanowires, making the preparation straightforward. It also acts as a bottom electrode for the device. A top Al electrode was fabricated by e-beam evaporation process. The Al/TiO_2 nanowire networks/Ti device fabricated in this way displayed a highly repeatable and electroforming-free bipolar resistive behavior with retention for more than 10~4 s and an OFF/ON ratio of approximately 70. The switching mechanism of this Al/TiO_2 nanowire networks/Ti device is suggested to arise from the migration of oxygen vacancies under applied electric field. This provides a facile way to obtain metal oxide nanowire-based Re RAM device in the future.

关键词： TiO2 nanowire networks Resistive switching memory Ti foil Hydrothermal process Al electrode

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AN ANALYSIS oF THE SHEAR FAILURE OF RIGID-LINEAR HARDENING BEAMS UNDER IMPULSIVE LOADING

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Acta Mechanica Sinica 1996年第4期12卷 338-348页

作者：王礼立 norman Jones Ningbo University Ningbo 315211China and also University of Science and Technology of ChinaHefei 230026China Impact Research Centre Department of Mechanical EngineeringUniversity of Liverpool.P.O.Box 147Liverpool L69 3BXU.K.

A theoretical rigid-plastic analysis for the dynamic shear failure of beams under impulsive loading is presented when using a travelling plastic shear hinge model which tabes into account material strain hardening. The maximum dynamic shear strain and shear strain-rate can be predicted in addition to the permanent transverse deflections and other parameters. The conditions for the three modes of shear failure, i.e., excess deflection failure, excess shear strain failure and adiabatic shear failure are analyzed. The special case of an infinitesimally small plastic zone is discussed and compared with Nonaka's solution for a rigid, perfectly plastic material. The results can also be generalized to examine the dynamic response of fibre-reinforced beams.

关键词： shear failure rigid-linear hardening plastic beam dynamic response impulsive loading adiabatic shear

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Accuracy assessment of real-time kinematics(RTK)measurements on unmanned aerial vehicles(UAV)for direct geo-referencing

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Geo-Spatial Information Science 2020年第2期23卷 165-181页

作者： Desta Ekaso Francesco Nex norman Kerle Department of Earth Systems Analysis ITC-Faculty of Geo-Information Science and Earth Observation of the University of TwenteEnschedeThe NetherlandsDepartment of Earth Systems AnalysisITC-Faculty of Geo-Information Science and Earth Observation of the University of TwenteEnschedeThe NetherlandsDepartment of Earth Systems AnalysisITC-Faculty of Geo-Information Science and Earth Observation of the University of TwenteEnschedeThe Netherlands

Geospatial information acquired with Unmanned Aerial Vehicles(UAV)provides valuable decision-making support in many different domains,and technological advances coincide with a demand for ever more sophisticated data *** consequence is a research and development focus on more accurately referenced images and derivatives,which has long been a weakness especially of low to medium cost UAV systems equipped with relatively inexpensive inertial measurement unit(IMU)and Global Navigation Satellite System(GNSS)*** research evaluates the positional accuracy of the real-time kinematics(RTK)GNSS on the DJI Matrice 600 Pro,one of the first available and widely used UAVs with potentially surveying-grade *** a very high positional accuracy of the drone itself of 2 to 3 cm is claimed by DJI,the actual accuracy of the drone RTK for positioning the images and for using it for mapping purposes without additional ground control is not *** begin with,the actual GNSS RTK position of reference center(the physical point on the antenna)on the drone is not indicated,and uncertainty regarding this also exists among the professional user *** this study the reference center was determined through a set of experiments using the dual frequency static Leica GNSS with RTK *** RTK positioning data from the drone were then used for direct georeferencing,and its results were *** flights were carried out over a 70 x 70 m area with an altitude of 40 m above the ground,with a ground sampling distance of 1.3 *** against ground control points,the planimetric accuracy of direct georeferencing for the photogrammetric product ranged between 30 and 60 *** of direct georeferencing results showed a time delay of up to 0.28 seconds between the drone GNSS RTK and camera image acquisition affecting direct georeferencing results.

关键词： UAV GNSS RTK direct georeferencing aerial triangulation lever arm offset

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A fusion at the root of prostate cancer

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Asian Journal of Andrology 2013年第5期15卷 592-593页

作者： norman J Maitland YCR Cancer Research Unit Dept of Biology Universityof York York Y010 5DD UK

Many hematopoietic malignancies have oncogenic gene fusions, like BCR-ABL, in their tumor-initiating cells. This implicates the product of the fusion as a powerful cancer-initiating event. In human prostate cancers, d... 详细信息

关键词： A fusion the root prostate cancer

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