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偏心树木圆盘半径的矫正

华东森林经理 1988年第2期 34-36页

作者： c.j.刘廖为明

生长锥钻入树干,特别是较大树干,常常会错过髓心,因此需要估计树木髓心的位置。在林业文献中尚没有论述过偏心生长年轮宽度的计算方法。本文就偏心生长圆盘的半径计算,提供一种简便的方法。阿卜里魁斯特于1958年曾利用一种叫做“髓心位... 详细信息

生长锥钻入树干,特别是较大树干,常常会错过髓心,因此需要估计树木髓心的位置。在林业文献中尚没有论述过偏心生长年轮宽度的计算方法。本文就偏心生长圆盘的半径计算,提供一种简便的方法。阿卜里魁斯特于1958年曾利用一种叫做“髓心位置标定”的装置估计偏心树干究竟

关键词：方程树干年轮宽度圆盘髓心

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近二十年的农业机械化

世界农业 1979年第8期 58-61页

作者： j.A.c.吉布雷丁大学农业工程学高级讲师

回顾近二十年来农业机械化发展的全景,令人惊异的是几乎看不到有什么突出的高峰。同前二十五年相比,近二十年来实在并没有太激动人心的东西,这是因为在前二十五年里,农业机械出现了一些带根本性的发展:如拖拉机和农用车辆采用了充气轮胎,

关键词：农业机械化机具拖拉机近二十年

Selective Adsorption of Molecules on Metal Surfaces

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Selective Adsorption of Molecules on Metal Surfaces

MAKING DUcTILE cAST IRON WITH ESR PROcESS

中国化学会第九届全国量子化学学术会议

作者： c．Seidel H．Kopf H．Fuchs S．j．Pennycook S．Pantelides Physics Institute uenster University MuensterGermany Physics Institute uenster University MuensterGermany Physics Institute uenster University MuensterGermany condensed Matter Sciences Division ak Ridge National Laboratory Oak Ridge 37831USA Department of PhysicsVanderbilt UniversityNashvilleTN38845USA condensed Matter Sciences Division ak Ridge National Laboratory Oak Ridge 37831USA Department of PhysicsVanderbilt UniversityNashvilleTN38845USA

＜正＞Selective adsorption of different molecules on the same surfaces is an effective technique of controllable design of multifunctional molecular devices. To study the mechanism of selective adsorption, two organic molecules with different sizes and different functional groups, 3,4,9,10-perylene-tetracarboxylicacid-dianhydride （PTcDA） and 2, 5-dimethyl-N, N’-dicyano-quinonediimine （DMe-DcNQI）, are evaporated on a designed Ag（775） substrate with two facets

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Acta Metallurgica Sinica(English Letters) 1998年第3期11卷 169-174页

作者： S.j.chu H.H.Lou Q.Niu Univ of Science and Technology Beijing Beijing China

Making ductile cast iron with ESR process under D.c. condition without adding spheroidizing inoculant alloys has been studied in laboratory. The key operation of ESR for cast iron is increasing the silicon content in unrefined consumable electrodes of flake graphite cast iron and using caF2-based slags containing rare-earth or basic oxides and magnesium fluoride. The samples excel ductile cast iron produced by general technological process in fatigue strength and sealing performance.

关键词： ductile cast iron electroslag remelting nodulizing element

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Brain-targeting,acid-responsive antioxidant nanoparticles for stroke treatment and drug delivery

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Bioactive Materials 2022年第10期7卷 57-65页

作者： Shenqi Zhang Bin Peng Zeming chen jiang Yu Gang Deng Youmei Bao chao Ma Fengyi Du Wendy c.Sheu W.Taylor Kimberly j.Marc Simard Daniel coman Qianxue chen Fahmeed Hyder jiangbing Zhou Kevin N.Sheth Department of Neurosurgery USA Department of Biomedical Engineering USA Department of Radiology and Biomedical Imaging USA Department of Neurology Yale UniversityNew HavenCT06510USA Department of Neurosurgery Renmin Hospital of Wuhan UniversityWuhanHubei430060China Department of Neurology Division of Neurocritical CareMassachusetts General HospitalBostonMAUSA Department of Neurosurgery University of Maryland School of MedicineBaltimoreMD21201USA

Stroke is the leading cause of death and ***,there is no effective pharmacological treatment for this disease,which can be partially attributed to the inability to efficiently deliver therapeutics to the *** we report the development of natural compound-derived nanoparticles(NPs),which function both as a potent therapeutic agent for stroke treatment and as an efficient carrier for drug delivery to the ischemic ***,we screened a collection of natural nanomaterials and identified betulinic acid(BA)as one of the most potent antioxidants for stroke ***,we engineered BA NPs for preferential drug release in acidic ischemic tissue through chemically converting BA to betulinic amine(BAM)and for targeted drug delivery through surface conjugation of AMD3100,a cXcR4 *** resulting AMD3100-conjugated BAM NPs,or A-BAM NPs,were then assessed as a therapeutic agent for stroke treatment and as a carrier for delivery of NA1,a neuroprotective *** show that intravenous administration of A-BAM NPs effectively improved recovery from stroke and its efficacy was further enhanced when NA1 was *** to their multifunctionality and significant efficacy,we anticipate that A-BAM NPs have the potential to be translated both as a therapeutic agent and as a drug carrier to improve the treatment of stroke.

关键词： Drug delivery Acid-triggered release Antioxidant nanoparticles NA1 Ischemic stroke

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研究景观地面特征的工具——机载激光仪

水土保持科技情报 1993年第3期11卷 59-62页

作者： j.c.Ritchie 孙桐

利用机载激光断面仪可测出与侵蚀、水文有关的景观地面特征.断面仪每秒4000测次,单次测量记录精度为5cm.激光器获取的数字数据用微机记录并分析.这些机载激光断面仪可提供景观地面特征方面的信息.在南得克萨斯的研究中测定了地形和自然... 详细信息

利用机载激光断面仪可测出与侵蚀、水文有关的景观地面特征.断面仪每秒4000测次,单次测量记录精度为5cm.激光器获取的数字数据用微机记录并分析.这些机载激光断面仪可提供景观地面特征方面的信息.在南得克萨斯的研究中测定了地形和自然植被的覆盖高度、覆盖率及分布.沿航线灌木覆盖的激光航测值同设线截距取样法获取的地面测量值密切相关(R^2=0.98).利用激光航测数据可迅速准确求出河流的河槽断面图,还可测出休闲平地和成熟大豆地中的小切沟.传统地面技术也能完成上述测量,但激光航测技术却能快速地高密度采集数据,特别是在地面勘测难以实施之处更为有用.激光航测断面数据可定量描述有关侵蚀、径流的景观特征,因此激光断面仪有可能成为一种为研究和管理自然资源提供更多数据的有效工具.

关键词：机载激光仪测定景观

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平面回波扩散加权MR成像和PROPELLER扩散加权MR成像评估涎腺的ADc值

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国际医学放射学杂志 2009年第6期 585-586页

作者： c.j.Hsueh 杨栋 Department of Radiology National Defense Medical CenterTaipeiTaiwanRepublic of China

目的应用螺旋桨(PROPELLER)技术与平面回波技术对腮腺进行扩散加权MR成像(DWI),比较两种技术DWI影像的失真度并进行ADc定量分析,同时探讨腮腺ADc值与腮腺脂肪含量的关系。材料与方法本研究经伦理委员会批准并获得病人知情同意。33例

关键词：扩散加权 PROPELLER 回波脂肪饱和 MR ADc

The carbon fluxes in different successional stages:modelling the dynamics of tropical montane forests in South Ecuador

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Forest Ecosystems 2017年第2期4卷 143-153页

作者： sebastian paulick claudia dislich jürgen homeier rico fischer andreas huth Department of Ecological Modelling Helmholtz Centre for Environmental Research-UFZPermoserstr1504318 LeipzigGermany Georg-August-University Gottingen Plant EcologyUntere KarspOle 237073 GottingenGermany University of Osnabriick Institute of Environmental Systems ResearchBarbarastr1249076 OsnabruckGermany iDiv German Centre for Integrative Biodiversity Research(iDiv)Halle-Jena-LeipzigDeutscher Platz 5e04103 LeipzigGermany

Background： Tropical forests play an important role in the global carbon（c） ***, tropical montane forests have been studied less than tropical lowland forests, and their role in carbon storage is not well *** forests are highly endangered due to logging, land-use and climate *** objective was to analyse how the carbon balance changes during forest ***： In this study, we used a method to estimate local carbon balances that combined forest inventory data with process-based forest *** utilised such a forest model to study the carbon balance of a tropical montane forest in South Ecuador, comparing two topographical slope positions（ravines and lower slopes vs upper slopes and ridges）.Results： The simulation results showed that the forest acts as a carbon sink with a maximum net ecosystem exchange（NEE） of 9.3 Mg c？（ha？yr）-1during its early successional stage（0–100 years）.In the late successional stage, the simulated NEE fluctuated around zero and had a variation of 0.77 Mg c？（ha？yr）–*** simulated variability of the NEE was within the range of the field *** discovered several forest attributes（e.g., basal area or the relative amount of pioneer trees） that can serve as predictors for NEE for young forest stands（0–100 years） but not for those in the late successional stage（500–1,000 years）.In case of young forest stands these correlations are high, especially between stand basal area and ***： In this study, we used an Ecuadorian study site as an example of how to successfully link a forest model with forest inventory data, for estimating stem-diameter distributions, biomass and aboveground net primary *** conclude, this study shows that process-based forest models can be used to investigate the carbon balance of tropical montane *** this model it is possible to find hidden relationships between forest attributes and forest carbon *** relationships promote a better understandin

关键词： Forest model Tropical montane forest Forest succession carbon balance Forest productivity FORMIND

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comparative water relations of co-occurring trees in a mixed podocarp-broadleaf forest

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journal of Plant Ecology 2019年第1期12卷 163-175页

作者： julia Kaplick Michael j.clearwater cate Macinnis-Ng School of Biological Sciences University of AucklandPrivate Bag 92019Auckland 1142New Zealand School of Science University of WaikatoPrivate Bag 3105Hamilton 3240 New Zealand

Aims As extreme climatic events including droughts and heat waves become more common in a changing climate,tree mortality has increased across the *** order to determine whether certain species have a competitive advantage over others,we explored the water-relations and leaf-gas exchange of four co-occurring spe-cies in a forest in northern Aotearoa-New *** studied the ecologically and culturally significant foundation species,Agathis australis(a conifer),two additional conifers,Phyllocladus tricho-manoides and Podocarpus totara and the angiosperm Knightia *** We measured sap flow,leaf-gas exchange and xylem water poten-tials of leaves and terminal branches with concurrent measures of micrometeorological data on days with very few *** derived whole tree hydraulic conductance and instantaneous water-use efficiency(WUEi)at our remnant forest in west Auckland during February 2015(southern hemisphere summer).Important Findings The four species behaved similarly in their diurnal curves of gas exchange and water *** of assimilation,stomatal con-ductance and WUEi were similar among trees of different *** tree hydraulic conductance was also similar among *** results indicate functional convergence in water relations,possibly driven by low nutrient soils at the *** results suggest that there is no species with a clear adaptive advantage over the others in the context of climate change.

关键词： southern conifers sap flow water potential hydraulic conductance leaf-gas exchange functional convergence