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Growth at the microscale:long term thinning effects on patterns and timing of intra-annual stem increment in radiata pine

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Forest Ecosystems 2018年第4期5卷 438-450页

作者： David m.Drew geoffrey m.downes Department of Forest and Wood Science Stellenbosch UniversityPrivate Bag X1Matieland 7800South Africa Forest Quality Pty Ltd PO Box 293 HuonvilleTASAustralia.

Background: Stem radial growth in forests is not uniform. Rather, it is characterized by periods of relatively fast or slow growth, or sometimes no growth at all. These fluctuations are generally a function of varying environmental conditions(e.g. water availability) and, importantly, will also be associated with adjustments in proprties in the wood formed. Stand level conditions and forest management, particularly thinning and stand density will, thowever, also have a major influence on patterns of growth variation. We explore how different thinning histories and/or stand densities influence these dynamics of tree growth in the important commercial plantation species Pinus radiata D. ***: Daily stem size change was measured using electronic point dendrometers over two growing seasons on P. radiata trees at two sites, subjected to different thinning regimes. Timing, rates and periodicity of annual growth were calculated from these ***: Greater overall cross-sectional growth in thinned plots was driven mainly by two dynamics. First, the cessation of seasonal growth occurred at least 3 weeks later in the stands in which thinning had taken place. There was no difference between thinned/unthinned stands, however, in the timing of growth onset. Second, within the longer season, trees in thinned plots had more growth days(as much as 20% more) than unthinned plots. The rates of growth on days when growth occurred were not different, however. In this context, it is notable that in trees in the unthinned plots experiencing the most severe competition there were strong "pulses" of growth following drought-breaking rainfall events. Unthinned plots at high stand densities also maintained a smaller(but consistent) zone of dividing cells throughout the season than thinned ***: In Pinus radiata growing under conditions as in our study, conditions late in summer, particularly drought, have an important effect on the timing of cessation of growth. Earl

关键词： monterey pine Dendrometer Intra-annual growth Drought Thinning

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桉树人工林木材密度的变化

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桉树科技 1999年第1期16卷 48-57页

作者： geoffrey m.downes Carolyn A.Raymond 彭彦桉树研究中心

关于木材密度的各种调查数据之间存在着明显的矛盾,每个人都认为自己的数据是精确的,他们之间的矛盾是可以理解的,因为我们没有必需的资料来充分地解释这种差异,所以这些数据在所发表的不同的论文中有着明显的差异。从子代试验的结果来... 详细信息

关于木材密度的各种调查数据之间存在着明显的矛盾,每个人都认为自己的数据是精确的,他们之间的矛盾是可以理解的,因为我们没有必需的资料来充分地解释这种差异,所以这些数据在所发表的不同的论文中有着明显的差异。从子代试验的结果来看,似乎在树木家系中生长得越快的树反而木材密度愈低。因此,在比较家系的生长率与木材密度的关系时,常常表现出弱的负相关关系。然而,也有几份研究报告指出,通过营林措施可以在提高树木生长率的同时,提高木材的密度。为了更进一步了解这种关系,必须知道有关木材的构造,特别是关于导管的尺寸和分布频度。关于这种矛盾的另外一个解释是:各种措施对木材密度的巨大影响对于自然条件的变化所产生的影响来说还是较小的,所以,试图建立各种变化趋势是困难的。现在,似乎能得出的结论是任何关于生长率对木材密度的影响在平衡地考虑营林和育种的影响力之内都被谨慎地认为是极小的和可能的。

关键词：桉树人工林生长率木材密度相关关系

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Reducing Value Chain Vulnerability to Terrorist Attacks

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化工进展 2005年第6期24卷 697-702页

作者： A.m.(Tony) downes FmC Corporation Princeton NJ 08543

Like most U.S. chemical companies, you probably know where your security-sensitive inventories are located within your sites and have assured yourself that you have taken reasonable precautions to reduce the risk of their being used in a terrorist attack. What about when you ship them? How secure are the various parts of your value chain-offsite storage and transportation of your products, raw materials, intermediates, and wastes, and processing of ordering and invoicing transactions? Value chain security focuses on tampering and misuse of materials handled outside the plant *** FmC, we took a three-stage approach to identifying and dealing with potential security issues posed by materials in transit. Stage 1 was a quick review to determine which of our products, intermediates, or raw materials might be potentially useful to terrorists. In Stage 2 we looked for specific security-emergency scenarios that might involve those chemicals, estimated the risk of those scenarios, and made recommendations to reduce the vulnerability to terrorist attack. In Stage 3 we are implementing the plans we ***’s approach has successfully focused our efforts and used familiar techniques to break down complex Value Chains into manageable sections and then to identify the possible scenarios and (relative) risks at each section. We were able to do this with minimal travel *** paper describes the general organization of FmC’s value chain security efforts and our analysis technique, and discusses lessons (including a few surprises) that we have learned from the analyses. 2005 American Institute of Chemical Engineers Process Saf Prog 24: 6-11, 20051. ORGANIZATION (FORmAL AND INFORmAL) OF SECURITY ACTIVITIESShortly after the terrorist attack on September 11, 2001, FmC Corporation formed a Transportation Secu-

关键词：化工企业安全管理安全生产价值链

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Nonlinear forced vibration in a subcritical regime of a porous functionally graded pipe conveying fluid with a retaining clip

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Applied mathematics and mechanics(English Edition) 2025年第1期46卷 101-122页

作者： m.GHOLAmI m.EFTEKHARI Department of mechanical Engineering Shahid Bahonar University of Kerman

This study examines the nonlinear behaviors of a clamped-clamped porous pipe made of a functionally graded material(FGm) that conveys fluids and is equipped with a retaining clip, focusing on primary resonance and subcritical dynamics. The nonlinear governing equations for the FGm pipe are derived by the extended Hamilton's principle, and subsequently discretized through the application of the Galerkin *** direct method of multi-scales is then used to solve the derived equations. A thorough analysis of various parameters, including the clip stiffness, the power-law index, the porosity, and the clip location, is conducted to gain a comprehensive understanding of the system's nonlinear dynamics. Through the analysis of the first natural frequency, the study highlights the influence of the flow velocity and the clip stiffness, while the comparisons with metallic pipes emphasize the role of FGm composition. The examination of the forced response curves reveals saddle-node bifurcations and their dependence on parameters such as the detuning parameter and the power-law index, offering valuable insights into the system's nonlinear resonant behavior. Furthermore, the frequency-response curves illustrate the hardening nonlinearities influenced by factors such as the porosity and the clip stiffness, revealing nuanced effects on the system response and resonance characteristics. This comprehensive analysis enhances the understanding of nonlinear behaviors in FGm porous pipes with a retaining clip, providing key insights for practical engineering applications in system design and optimization.

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Grain production trends in Russia, Ukraine and Kazakhstan： New opportunities in an increasingly unstable world？

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Frontiers of Earth Science 2012年第2期6卷 157-166页

作者： Elena LIOUBImTSEVA geoffrey m. HENEBRY2 Geography and Planning Department and Environmental Studies Program Grand Valley State University Allendale MI 49401-9403 USA Geographic Information Science Center of Excellence South Dakota State University Brookings SD 57007-3510 USA

Grain production in the countries of the former USSR sharply declined during the past two decades and has only recently started to recover. In the context of the current economic and food-price crisis, Russia, Ukraine, and Kazakhstan might be presented with a window of opportunity to reemerge on the global agricultural market, if they succeed in increasing their productivity. The future of their agriculture, however, is highly sensitive to a combination of internal and external factors, such as institutional changes, land-use changes, climate variability and change, and global economic trends. The future of this region＇s grain production is likely to have a significant impact on the global and regional food security over the next decades.

关键词： Russia Ukraine Kazakhstan food security,global change grain production

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Evolving paradigms for natural-product drug discovery

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National Science Review 2022年第11期9卷 10-11页

作者： geoffrey A.Cordell College of Pharmacy University of Florida Natural Products Inc.

Natural products are an essential aspect of global human health. Integration of contemporary technologies based on the Fourth Industrial Revolution (4IR) and the Quintuple Helix is needed to discover additional metabo...

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Neurogenesis dynamics in the olfactory bulb:deciphering circuitry organization, function, and adaptive plasticity

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Neural Regeneration Research 2025年第6期20卷 1565-1581页

作者： moawiah m.Naffaa Department of Psychology and Neuroscience Duke UniversityDurhamNCUSA Department of Cell Biology Duke University School of MedicineDurhamNCUSA

Adult neurogenesis persists after birth in the subventricular zone, with new neurons migrating to the granule cell layer and glomerular layers of the olfactory bulb, where they integrate into existing circuitry as inhibitory interneurons. The generation of these new neurons in the olfactory bulb supports both structural and functional plasticity, aiding in circuit remodeling triggered by memory and learning processes. However, the presence of these neurons, coupled with the cellular diversity within the olfactory bulb, presents an ongoing challenge in understanding its network organization and function. moreover,the continuous integration of new neurons in the olfactory bulb plays a pivotal role in regulating olfactory information processing. This adaptive process responds to changes in epithelial composition and contributes to the formation of olfactory memories by modulating cellular connectivity within the olfactory bulb and interacting intricately with higher-order brain regions. The role of adult neurogenesis in olfactory bulb functions remains a topic of debate. Nevertheless, the functionality of the olfactory bulb is intricately linked to the organization of granule cells around mitral and tufted cells. This organizational pattern significantly impacts output, network behavior, and synaptic plasticity, which are crucial for olfactory perception and memory. Additionally, this organization is further shaped by axon terminals originating from cortical and subcortical regions. Despite the crucial role of olfactory bulb in brain functions and behaviors related to olfaction, these complex and highly interconnected processes have not been comprehensively studied as a whole. Therefore, this manuscript aims to discuss our current understanding and explore how neural plasticity and olfactory neurogenesis contribute to enhancing the adaptability of the olfactory system. These mechanisms are thought to support olfactory learning and memory, potentially through increased

关键词： network adaptability neurogenesis neuronal communication olfactory bulb olfactory learning olfactory memory synaptic plasticity

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modeling limit force capacities of high force to volume lead extrusion dampers

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Frontiers of Structural and Civil Engineering 2021年第3期15卷 609-622页

作者： V.VISHNUPRIYA geoffrey.W.RODGERS J.geoffrey CHASE Department of mechanical Engineering University of CanterburyChristchurch8140New Zealand QuakeCoRE NZ Centre for Earthquake Resilience Christchurch8041New Zealand

Lead extrusion dampers are supplemental energy-dissipation devices that are used to mitigate seismic structural *** volumetric sizes and high force capacities define high-force-to-volume(HF2V)devices,which can absorb significant response energy without sacrificial ***,the design of such devices for specific force capacities has proven difficult based on the complexities of their internal reaction mechanisms,leading to the adoption of empirical *** study developed upper-and lower-bound force capacity estimates from analytical mechanics based on direct and indirect metal extrusion for guiding *** derived equations are strictly functions of HF2V device geometric parameters,lead material properties,and extrusion *** upper-bound estimates from direct and indirect extrusion are denoted as(F_(UB,1),F_(UB,2))and(F_(UB,3),F_(UB,4)),respectively,and the lower-bound estimates are denoted as(F_(LB),F_(LB,1))based on the combination of extrusion and friction *** proposed models were validated by comparing the predicted bounds to experimental force capacity data from 15 experimental HF2V device *** experimental device forces all lie above the lower-bound estimates(F_(LB),F_(LB,1))and below the upper-bound estimates(F_(UB,1),F_(UB,2),F_(UB,4)).Overall,the(F_(LB),F_(UB,2))pair provides wider bounds and the(F_(LB,1),F_(UB,4)/F_(UB,1))pair provides narrower ***(F_(LB,1),F_(UB,1))pair has a mean lower-bound gap of 36%,meaning the lower bound was 74%of the actual device force on *** mean upper-bound gap was 33%.The bulge area and cylinder diameter of HF2V devices are key parameters affecting device *** relatively tight bounds provide useful mechanics-based predictive design guides for ensuring that device forces are within the targeted design range after manufacturing.

关键词： extrusion lead dampers upper and lower bound analytical modelling limit force

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mitochondria–cGAS–STING axis is a potential therapeutic target for senescence-dependent inflammaging-associated neurodegeneration

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Neural Regeneration Research 2025年第3期20卷 805-807页

作者： Josém.Izquierdo Centro de Biología molecular Severo Ochoa(CBm) Consejo Superior de Investigaciones Científicas-Universidad Autónoma de Madrid(CSIC-UAM)MadridSpain

The word “senescence” comes from the Latin senescens, meaning “to begin to age”, and is characterized by a long-lasting but reversible block in proliferation, resulting from stress-induced cell cycle arrest of pre... 详细信息

关键词： Latin potential lasting

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Combined analysis of land cover change and NDVI trends in the Northern Eurasian grain belt

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Frontiers of Earth Science 2012年第2期6卷 177-187页

作者： Christopher K. WRIGHT Kirsten m. de BEURS geoffrey m. HENEBRY South Dakota State University Geographic Information Science Center of Excellence (GIScCE) Brookings South Dakota 57007 USA The University of Oklahoma Department of Geography and Environmental Sustainability Norman OK 73019 USA

We present an approach to regional environ- mental monitoring in the Northern Eurasian grain belt combining time series analysis of mODIS normalized difference vegetation index （NDVI） data over the period 2001-2008 and land cover change （LCC） analysis of the 2001 and 2008 mODIS Global Land Cover product （mCD 12Q 1）. NDVI trends were overwhelmingly negative across the grain belt with statistically significant （p ≤0.05） positive trends covering only 1% of the land surface. LCC was dominated by transitions between three classes; cropland, grassland, and a mixed cropland/natural vegeta- tion mosaic. Combining our analyses of NDVI trends and LCC, we found a pattern of agricultural abandonment （cropland to grassland） in the southern range of the grain belt coinciding with statistically significant （p≤0.05） negative NDVI trends and likely driven by regional drought. In the northern range of the grain belt we found an opposite tendency toward agricultural intensification; in this case, represented by LCC from cropland mosaic to pure cropland, and also associated with statistically significant （p≤0.05） negative NDVI trends. Relatively small clusters of statistically significant （p ≤ 0.05） positive NDVI trends corresponding with both localized land abandonment and localized agricultural intensification show that land use decision making is not uniform across the region. Land surface change in the Northern Eurasian grain belt is part of a larger pattern of land cover land use change （LCLUC） in Eastern Europe, Russia, and former territories of the Soviet Union following realignment of socialist land tenure and agricultural markets. Here, we show that a combined analysis of LCC and NDVI trends provides a more complete picture of the complex- ities of LCLUC in the Northern Eurasian grain belt,involving both broader climatic forcing, and narrower anthropogenic impacts, than might be obtained from either analysis alone.

关键词： land cover change mODIS NDVI NorthernEurasian grain belt Kazakhstan Russia time seriesanalysis Ukraine

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