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中国陆地水元素组成的中子活化分析试验

水科学进展 2003年第5期14卷 535-541页

作者：顾慰祖陆家驹陈廷扬徐其高 norman e.peters 南京水利科学研究院南京大学物理系江苏南京210093 U.S.Geological Survey atlantaga30360

对同期降水、江河水和地下水的元素组成,使用中子活化分析方法作了对比试验。降水取自分布于8个气候带的11个站,其海拔高程为5～3659m,年平均降水量为50～1571mm。河水取自各主要江河包括内陆河和海岛的12个测站以及3个实验流域,并在其... 详细信息

对同期降水、江河水和地下水的元素组成,使用中子活化分析方法作了对比试验。降水取自分布于8个气候带的11个站,其海拔高程为5～3659m,年平均降水量为50～1571mm。河水取自各主要江河包括内陆河和海岛的12个测站以及3个实验流域,并在其附近采集地下水。降水中共检出35种元素,各站有19～31种元素,同期均有空间分布。河水中共检出39种元素,各河分别有21～31种元素。地下水中共检出35种元素,各站有30～32种元素。对其浓度组成作了由大于1000μg/L至小于0 01μg/L的分级综合。有些元素含量超出所报道的世界淡水浓度范围,小于其最低值,甚或远大于其最高值。

关键词：陆地水元素组成中子活化分析试验降水江河水地下水中国

Critiquing and Joining Intersections of Disaster,Conflict,and Peace Research

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International Journal of Disaster Risk Science 2020年第5期11卷 555-567页

作者： Laura e.R.peters Ilan Kelman College of earth.Ocean and Atmospheric SciencesOregon State UniversityCorvallis.OR 97331USA Institute for Risk and Disaster Reduction and Institute for Global HealthUniversity College LondonLondon WC1E 6BT.UK University of Agder.4630 Kristiansand Norway

Disaster research,conflict research,and peace research have rich and deep histories,yet they do not always fully intersect or learn from each other,even when they investigate if and how disasters lead to conflict or *** has tended to focus on investigating causal linkages between disaster(including those associated with climate change)and conflict,and disaster diplomacy emerged as a thread of explanatory research that investigates how and why disaster-related activities do and do not in fluence peace and ***,definitive conclusions on the disaster-conflict-peace nexus have evaded scientific consensus,in part due to conceptual,methodological,and interpretive differences among *** article highlights that this nexus would benefit from a more robust engagement with each field's foundational research that explores beyond binary and crude *** are concepts of destructive and constructive conflict;direct,structural,and cultural violence,and their relationships to vulnerability;negative and positive peace;and the ideals and realities of peacebuilding and conflict *** article demonstrates how integrated scholarship could open up and advance new lines of questioning,with implications for developing cohere nt research,policy,and *** article concludes by offering recommendations for how to better connect disaster,conflict,and peace research.

关键词： Climate change Conflict research Disaster diplomacy Disaster risk reduction Peace research

Advanced biomedical hydrogels:molecular architecture and its impact on medical applications

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Regenerative Biomaterials 2021年第6期8卷 297-317页

作者： Jonathan T.peters Marissa e.Wechsler Nicholas A.Peppas McKetta Department of Chemical engineering The University of Texas at AustinAustin200 E.Dean KeetonAustinTX 78712USA Institute for Biomaterials Drug Deliveryand Regenerative MedicineThe University of Texas at Austin107 W.Dean KeetonAustinTX 78712USA Department of Biomedical engineering and Chemical engineering The University of Texas at San AntonioOne UTSA CircleSan AntonioTX78249USA Department of Biomedical engineering The University of Texas at Austin107 W.Dean KeetonAustinTX 78712USA Division of Molecular Pharmaceutics and Drug Delivery College of PharmacyThe University of Texas at Austin107 W.Dean KeetonAustinTX 78712USA Department of Surgery and Perioperative Care and Department of PediatricsDell Medical SchoolThe University of Texas at Austin1601 Trinity St.Bldg.BAustinTX 78712USA

Hydrogels are cross-linked polymeric networks swollen in water,physiological aqueous solutions or biological *** are synthesized by a wide range of polymerization methods that allow for the introduction of linear and branched units with specific molecular *** addition,they can be tuned to exhibit desirable chemical characteristics including hydrophilicity or *** synthesized hydrogels can be anionic,cationic,or amphiphilic and can contain multifunctional crosslinks,junctions or tie *** these characteristics,hydrogels exhibit compatibility with biological systems,and can be synthesized to render systems that swell or collapse in response to external *** versatility and compatibility have led to better understanding of how the hydrogel’s molecular architecture will affect their physicochemical,mechanical and biological *** present a critical summary of the main methods to synthesize hydrogels,which define their architecture,and advanced structural characteristics for macromolecular/biological applications.

关键词： hydrogels networks mesh size hydrogel reactions biological applications biomedical applications

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

A framework for quantifying properties of 3-dimensional movement-based signals

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Current Zoology 2010年第3期56卷 327-336页

作者： Shaun TD NeW Richard A peters ARC Centre of excellence in Vision Science Division of EvolutionEcology & GeneticsResearch School of BiologyThe Australian National University

Understanding how signal properties are optimized for the reliable transmission of information requires accurate de- scription of the signal in time and space. For movement-based signals where movement is restricted to a single plane, measure- ments from a single viewpoint can be used to consider a range of viewing positions based on simple geometric calculations. However, considerations of signal properties from a range of viewing positions for movements extending into three-dimensions （3D） are more problematic. We present here a new framework that overcomes this limitation, and enables us to quantify the extent to which movement-based signals are view-specific. To illustrate its application, a Jacky lizard tail flick signal was filmed with synchronized cameras and the position of the tail tip digitized for both recordings. Camera aligmnent enabled tl^e construction of a 3D display action pattern profile. We analyzed the profile directly and used it to create a detailed 3D animation. In the virtual environment, we were able to film the same signal from multiple viewing positions and using a computational motion analysis algorithm （gradient detector model） to measure local image velocity in order to predict view dependent differences in signal properties. This approach will enable consideration of a range of questions concerning movement-based signal design and evolu- tion that were previously out of reach [Current Zoology 56 （3）： 327-336, 2010].

关键词： Signal evolution Sensory ecology Movement-based signal 3D Display Action Pattern

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

Organic Gases in Fluid Inclusions of Ore Minerals and Their Constraints on Ore Genesis:A Case Study of the Changkeng Au-Ag Deposit,Guangdong,China

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Acta Geologica Sinica(english edition) 2003年第1期77卷 86-94页

作者： DavidI.norman Department of earth & environmental Sciences New Mexico Institute of Mining and Technology (NMT) Socorro NM87801 USA

The newly discovered Changkeng Au-Ag deposit is a new type of sediment-hostedprecious metal deposit. Most of the previous researchers believed that the deposit was formed bymeteoric water convection. By using a high vacuum quadrupole gas mass spectrometric system, ninelight hydrocarbons have been recognized in the fluid inclusions in ore minerals collected from theChangkeng deposit. The hydrocarbons are composed mainly of saturated alkanes C_(1-4) and unsaturatedalkenes C_(2-4) and aromatic hydrocarbons, in which the alkanes are predominant, while the contentsof alkenes and aromatic hydrocarbons are very low. The sum alka/sum alke ratio of most samples ishigher than 100, suggesting that those hydrocarbons are mainly generated by pyrolysis of kerogens insedimentary rocks caused by water-rock interactions at medium-low temperatures, and themetallogenic processes might have not been affected by magmatic activity. A thermodynamiccalculation shows that the light hydrocarbons have reached chemical equilibrium at temperatureshigher than 200 deg C, and they may have been generated in the deep part of sedimentary basins(e.g., the Sanzhou basin) and then be transported by ore-forming fluids to a shallow position of thebasin via a long distance. Most of the organic gases are generated by pyrolysis of the type IIkerogens (kukersite) in sedimentary host rocks, only a few by microorganism activity. Thecompositions and various parameters of light hydrocarbons in gold ores are quite similar to those insilver ores, suggesting that the gold and silver ores may have similar metallogenic *** on the compositions of organic gases in fluid inclusions, the authors infer that the Changkengdeposit may be of a tectonic setting of continental rift. The results of this study support fromone aspect the authors' opinion that the Changkeng deposit is not formed by meteoric waterconvection, and that its genesis has a close relationship with the evolution of the Sanzhou basin,so it belon

关键词： ore mineral fluid inclusion organic gas Changkeng Au-Ag deposit

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

Small-scale convection beneath oceans and continents

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Science Bulletin 2011年第13期56卷 1292-1320页

作者： SLeeP norman H. Department of Geophysics Stanford University

Small-scale convection supplies heat flow of ～17 mW m-2 to the base of stable continents where xenolith studies resolve the ***,effects of small-scale convection are difficult to resolve in ocean *** first pass,most seafloor appears to subside to an asymptote compatible with ～40 mW m-2 convective heat *** common regions are tracked by hotspots so uplift associated with ponded mantle material is an attractive *** seafloor in the North and South Atlantic continues to subside with the square root of age as expected from pure *** theory of stagnant-lid convection provides good scaling relationships for heat *** linear viscosity,heat flow is proportional to the underlying "half-space" viscosity to the 1/3 power and the temperature to change viscosity by a factor of e to the 4/3 *** formalism is easily modified to represent convection beneath a lid of highly viscous and buoyant cratonal lithosphere and to represent transient convection beneath thickening oceanic *** mantle with linear,strongly temperature-dependent,and weakly depth-dependent viscosity is compatible with both oceanic and continental *** complicated rheology may allow vigorous small-scale convection under most but not all old ocean *** viable hypotheses require poorly understood global features,including lateral variations of asthenospheric *** studies have the potential to resolve the lithosphere-asthenosphere boundary,including local variations of its depth associated with small-scale convection.

关键词： lithosphere asthenosphere ocean depth-age small-scale convection craton mantle plume