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Allometric models for estimating aboveground biomass in the tropical woodlands of Ghana, West Africa

Forest ecosystems 2020年第3期7卷 539-561页

作者： Raymond Aabeyir stephen Adu-Bredu Wilson Agyei Agyare Michael J.C.Weir Department of environment and Resource Studies UDS-Wa CampusWaGhana WASCAL Graduate Research Programme on Climate Change and Land Use KNUSTKumasiGhana Biodiversity Conservation and ecosystem Division CSIR-Forestry Research Institute of GhanaKumasiGhana Department of Agricultural and Biosystems engineering KNUSTKumasiGhana Department of Natural Resources Faculty of Geoinformation Science and Earth Observation(ITC)University of TwenteEnschedethe Netherlands

Background: Modelling aboveground biomass(AGB) in forest and woodland ecosystems is critical for accurate estimation of carbon stocks. However, scarcity of allometric models for predicting AGB remains an issue that has not been adequately addressed in Africa. In particular, locally developed models for estimating AGB in the tropical woodlands of Ghana have received little attention. In the absence of locally developed allometric models, Ghana will continue to use Tier 1 biomass data through the application of pantropic models. Without local allometric models it is not certain how Ghana would achieve Tier 2 and 3 levels under the United Nations programme for reducing emissions from deforestation and forest degradation. The objective of this study is to develop a mixedspecies allometric model for use in estimating AGB for the tropical woodlands in Ghana. Destructive sampling was carried out on 745 trees(as part of charcoal production) for the development of allometric equations. Diameter at breast height(dbh, i.e. 1.3 m above ground level), total tree height(H) and wood density(ρ) were used as predictors for the models. Seven models were compared and the best model selected based on model efficiency,bias(%) and corrected Akaike Information Criterion. The best model was validated by comparing its results with those of the pantropic model developed by Chave et al.(Glob Chang Biol 20:3177–3190, 2014) using equivalence test and conventional paired ***: The results revealed that the best model for estimating AGB in the tropical woodlands is AGB =0.0580ρ((dbh)2 H)0.999. The equivalence test showed that this model and the pantropic model developed by Chave et al.(Glob Chang Biol 20:3177–3190, 2014) were equivalent within ±10% of their mean predictions(p-values e-tailed t-tests for both lower and upper bounds at 5% significant level), while the paired t-test revealed that the mean(181.44 ± 18.25 kg) of the model predictions of the best model of this s

关键词： Charcoal Diameter at breast height Tree height Wood density Savannah woodland

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吴耀祖教授与我

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力学与实践 2025年第6期46卷 1129-1131页

作者：黄锷自然资源部第一海洋研究所山东青岛 266061

在吴耀祖教授的朋友中，我应该算是后来的。虽然早就听说过他的名字，但直到1995年底，我才在从当时的工作单位——美国NASA戈达德太空飞行中心赴加州理工学院访问时，第一次见到了吴教授。当时在他主持的学术报告会中报告我在波动融合... 详细信息

在吴耀祖教授的朋友中，我应该算是后来的。虽然早就听说过他的名字，但直到1995年底，我才在从当时的工作单位——美国NASA戈达德太空飞行中心赴加州理工学院访问时，第一次见到了吴教授。当时在他主持的学术报告会中报告我在波动融合方面的发现，即:短波变长并非是通过增大波长来实现的，而是由于短波通过局部和离散(非连续)将两个波动融合为一个，并推广到n个波动融合为(n-1)个波。报告结束后，吴教授把我带到他的办公室，除鼓励外还给了我两个建议：首先，建议我将在研究中使用的经验模态分解方法和希尔伯特变换申请专利；其次，访问加州理工学院一段时间，深入研究这些方法。

关键词：加州理工学院经验模态分解方法希尔伯特变换太空飞行戈达德学术报告会吴教授申请专利

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High risk cutaneous squamous cell carcinoma of the head and neck

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World Journal of Otorhinolaryngology-Head and Neck Surgery 2016年第2期2卷 -页

作者： stephen Y. Kang Amanda e. Toland Department of 0tolaryngology-Head and Neck Surgery The 0hio State University Wexner Medical Center The James Cancer Hospital and Solove Research Institute Columbus 0H USA Department of Molecular Virology Immunology&Medical Genetics Department of Internal Medicine The 0hio State University Wexner Medical Center Columbus 0H USA

The majority of patients with head and neck cutaneous squamous cell carcinoma (cSCC) are successfully treated with surgical treatment of the primary site. While only a minor-ity of patients is at risk for regional metastasis, these patients have significantly worse out-comes. Tumor and patient factors that place patients at high risk for development of regional metastasis have been identified. Advancing treatment of cSCC requires identifying and escalating treatment in this high risk patient population, while avoiding overtreatment of the majority of cSCC patients that do not develop regional metastasis. Sentinel lymph node biopsy has emerged as a promising technique in cSCC to detect micrometastasis and allow early surgical treatment of regional disease. Future directions involve genomic characteriza-tion of metastatic and nonmetastatic cSCC to identify genomic alterations causing metastasis that may be used to predict disease behavior. Copyright a 2016 Chinese Medical Association. Production and hosting by elsevier B.V. on behalf of KeAi Communications Co., Ltd. This is an open access article under the CC BY-NC-ND license (http://***/licenses/by-nc-nd/4.0/).

关键词： Squamous cell carcinoma Cutaneous Head and neck cancer

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Tanning capacityof Tessmannia burttii extracts:thepotentialeco-friendlytanning agents fortheleatherindustry

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Journal of Leather Science and engineering 2021年第1期3卷 149-157页

作者： Cecilia R.China stephen S.Nyandoro Joan J.e.Munissi Mihayo M.Maguta Michael Meyer Michaela Schroepfer Division of Textile and Leather Technologies Tanzania Industrial Research and Development OrganizationP.O.Box 2355Dar es SalaamTanzania Chemistry Department College of Natural and Applied SciencesUniversity of Dar es SalamP.O.Box 35061Dar es SalaamTanzania Department of environmental Planning Institute of Rural Development Planning(IRDP)P.O.Box 138DodomaTanzania FILK-Research Institute of Leather and Plastic Sheeting Meißner Ring 1-509599 FreibergGermany

In the present study,the tannins from stem and root barks of Tessmannia burttii Harms(Caesalpiniaceae),a plant species abundantly growing in Tanzania and other parts of Africa,were investigated for their suitability in hides *** powder was extracted at selected temperatures(30,50 and 80°C)and the influence of each temperature on the crosslinking capacity was *** interaction mechanism between hide powder collagen and the tannins was studied by Differential Scanning Calorimetry(DSC),trinitrobenzensulfonic(TNBS)acid assay and amino acid hydrolysis *** temperatures showed low influence on crosslinking capacity of the ***,extract obtained at 50°C exhibited best performance in terms of gap size between T onset and T *** stem bark extract yield was higher than that from the root bark,but both were within the recommended *** tannin content(61%)of *** stem bark extract was above recommended value(10%),whereas its total phenolic content and total flavonoic content were found to be above that of commercial Acacia mearnsii *** study of cross-linking parameters as a function of pH showed cross-linking to occur via a covalent mechanism at the basic amino ***,the bonds were not resistant to acid *** observed interaction mechanism indicated that tannins from stem and root barks of *** belong to the condensed tannin,similar to ***(black wattle),a commercial tannin source that was used in this study as a *** from this study depict that *** extracts are auspicious eco-friendly alternative source of vegetable tannins to overcome the use of chromium salts in the leather industry.

关键词： Tessmannia burttii Caesalpiniaceae Leather industry Vegetable tanning Tanning capacity

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evidence for structural phase transitions and large effective band gaps in quasi-metallic ultra-clean suspended carbon nanotubes

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Nano Research 2013年第10期6卷 736-744页

作者： Shun-Wen Chang Rohan Dhall Moh Amer Kentaro Sato Riichiro Saito stephen Cronin Department of Physics and Astronomy University of Southern California Los Angeles CA 90089 USA Department of electrical engineering University of Southern California Los Angeles CA 90089 USA Department of Chemistry University of Southern California Los Angeles CA 90089 USA Department of Physics Tohoku University Sendai 980-8578 Japan

We report evidence for a structural phase transition in individual suspended metallic carbon nanotubes by examining their Raman spectra and electron trans- port under electrostatic gate potentials. The current-gate voltage characteristics reveal anomalously large quasi-metallic band gaps as high as 240 meV, the largest reported to date. For nanotubes with band gaps larger than 200 meV, we observe a pronounced M-shape profile in the gate dependence of the 2D band （or G＇ band） Raman frequency. The pronounced dip （or softening） of the phonon mode near zero gate voltage can be attributed to a structural phase transition （SPT） that occurs at the charge neutrality point （CNP）. The 2D band Raman intensity also changes abruptly near the CNP, providing further evidence for a change in the lattice symmetry and a possible SPT. Pronounced non-adiabatic effects are observed in the gate dependence of the G band Raman mode, however, this behavior deviates from non-adiabatic theory near the CNP. For nanotubes with band gaps larger than 200 meV, non-adiabatic effects should be largely suppressed, which is not observed experimentally. This data suggests that these large effective band gaps are primarily caused by a SPT to an insulating state, which causes the large modulation observed in the conductance around the CNP. Possible mechanisms for this SPT are discussed, including electron-electron （e.g., Mott） and electron-phonon （e.g., Peierls） driven transitions.

关键词： carbon nanotube Raman spectroscopy phase transition bandgap energy

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Thermal conductivity of systems with a gap in the phonon spectrum

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Chinese Physics B 2018年第7期27卷 424-430页

作者： e Salamatov Udmurt Federal Research Center Ural Branch of the Russian Academy of Sciences

An original theoretical model for describing the low-temperature thermal conductivity in systems with a region of forbidden values （a gap） in the phonon spectrum is proposed. The model is based on new experimental results on the temperature dependence of the phonon diffusion coefficient in nanoceramics and dielectric glasses which showed a similar anomalous behavior of the diffusion coefficient in these systems that may be described under the assumption of a gap in the phonon spectrum. In this paper, the role of the gap in low-temperature behavior of the thermal conductivity, ~＇（T）, is analyzed. The plateau in the temperature dependence of the thermal conductivity is shown to correlate with the position and the width of the gap. The temperature dependence of thermal conductivity of such systems when changing the scat- tering parameters related to various mechanisms is studied. It is found that the umklapp process （U-processes） involving low-frequency short-wavelength phonons below the gap forms the behavior of the temperature dependence of thermal con- ductivity in the plateau region. A comparison of the calculated and experimental results shows considerable possibilities of the model in describing the low-temperature thermal conductivity in glass-like systems.

关键词： phononic band gap phonon diffusion coefficient thermal conductivity glassy crystals

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Recent Advances in the Unconventional Design of electrochemical energy Storage and Conversion Devices

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electrochemical energy Reviews 2022年第4期5卷 38-62页

作者： Senthil Velan Venkatesan Arpita Nandy Kunal Karan stephen R.Larter Venkataraman Thangadurai Department of Chemistry University of Calgary2500 University Drive NWCalgaryAB T2N1N4Canada Department of Chemical&Petroleum engineering University of Calgary2500 University Drive NWCalgaryAB T2N1N4Canada Department of Geoscience University of Calgary2500 University Drive NWCalgaryAB T2N1N4Canada

As the world works to move away from traditional energy sources,effective efficient energy storage devices have become a key factor for *** emergence of unconventional electrochemical energy storage devices,including hybrid batteries,hybrid redox flow cells and bacterial batteries,is part of the *** alternative electrochemical cell configurations provide materials and operating condition flexibility while offering high-energy conversion efficiency and modularity of design-to-design *** power of these diverse devices ranges from a few milliwatts to several ***-ing durable electronic and point-of-care devices is possible due to the development of all-solid-state batteries with efficient electrodes for long cycling and high energy *** batteries made of earth-abundant metal ions are approaching the capacity of lithium-ion *** are being reduced with the advent of flow batteries with engineered redox molecules for high energy density and membrane-free power generating electrochemical cells,which utilize liquid dynamics and interfaces(solid,liquid,and gaseous)for electrolyte *** batteries support electrode regeneration strategies for chemical and bio-batteries reducing battery energy *** batteries have different benefits,e.g.,carbon-neutral Li-CO_(2) batteries consume CO_(2) and generate power,offering dual-purpose energy storage and carbon *** work considers the recent technological advances of energy storage *** transition from conventional to unconventional battery designs is examined to identify operational flexibilities,overall energy storage/conversion efficiency and application ***,a list of facilities for large-scale deployment of major electrochemical energy storage routes is provided.

关键词： Unconventional energy storage Redox flow battery Organic electrolytes Membrane-free flow cell All-solid-state batteries

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Changes in Cinnamic Acid Derivatives Associated with the Habituation of Maize Cells to Dichlobenil

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Molecular Plant 2011年第5期4卷 869-878页

作者： Hugo Melida Jesus Alvarez Jose Luis Acebes Antonio encina stephen C. Fry Area de Fisiologia Vegetal Facultad de CC Biologicas y Ambientales Universidad de Leon E-24071 Leon Spain edinburgh Cell Wall Group Institute of Molecular Plant Sciences School of Biological Sciences University of Edinburgh Daniel Rutherford Building The King＇s Buildings Edinburgh EH9 3JH UK

The habituation of cell cultures to cellulose biosynthesis inhibitors such as dichlobenil （DCB） represents a valu- able tool to improve our knowledge of the mechanisms involved in plant cell wall structural plasticity. Maize cell lines habituated to lethal concentrations of DCB were able to grow through the acquisition of a modified cell wall in which cellulose was partially replaced by a more extensive network of arabinoxylans. The aim of this work was to investigate the phenolic metabolism of non-habituated and DCB-habituated maize cell cultures. Maize cell cultures were fed [14C]cinnamate and the fate of the radioactivity in different intra-protoplasmic and wall-localized fractions throughout the culture cycle was analyzed by autoradiography and scintillation counting. Non-habituated and habituated cultures did not markedly differ in their ability to uptake exogenous [14C]cinnamic acid. However, interesting differences were found in the radiolabeling of low- and high-Mr metabolites. Habituated cultures displayed a higher number and amount of radiola-beled low-Mr compounds, which could act as reserves later used for polysaccharide feruloylation. DCB-habituated cultures were highly enriched in esterified [14C]dehydrodiferulates and larger coupling products. In conclusion, an extensive and early cross-linking of hydroxycinnamates was observed in DCB-habituated cultures, probably strengthening their cellulose-deficient walls.

关键词： Cell wall Zea mays maize dichlobenil DCB dehydrodiferulate ferulate cinnamic acid.

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Nd-Hf Isotopic Decoupling of the Silurian–Devonian Granitoids in the Chinese Altai: A Consequence of Crustal Recycling of the Ordovician Accretionary Wedge?

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Journal of earth Science 2020年第1期31卷 102-114页

作者： Yanqiong Huang Yingd Jiang Yang Yu stephen Collett Sheng Wang Tan Shu Kang Xu State Key Laboratory of Isotope Geochemistry Guangzhou Institute of GeochemistryChinese Academy of SciencesGuangzhou 510640China University of Chinese Academy of Sciences Beijing 100049China Center for Lithospheric Research Czech Geological SurveyPragueCzech Republic

Voluminous Silurian–Devonian granitoids intruded a greywacke-dominated Ordovician accretionary wedge in the Chinese Altai. These granitoids are characterized by significant Nd-Hf isotopic decoupling, the underlying mechanism of which, so far, has been poorly understood. This issue is addressed in this study by the integration of our new and regional published geological and geochemical data. Geological studies indicated a close spatial relationship between the regional anatexis of the Ordovician wedge and the formation of the granitoids, which is characterized by a gradual textural evolution from the partial molten Ordovician wedge sedimentary rocks(the Habahe Group) to the granitoid bodies. Compositionally, these granitoids and the Ordovician Habahe Group rocks displayed close geochemical similarities, in the form of arclike trace elemental signatures as well as comparable Nd isotopic characteristics. Combined with regional available data, we suggest that the Silurian–Devonian granitoids originated from the immature and chemically primitive Habahe Group rocks. Since Nd and Hf isotopic data for the Habahe Group rocks show significant Nd-Hf isotopic decoupling, we propose that the Silurian–Devonian granitoids inherited the Nd and Hf isotopic signatures from their sources, i.e., the Habahe Group rocks. In other words, the Nd-Hf decoupling in the Habahe Group rocks is the primary causative factor leading to the prevailing Nd-Hf isotopic decoupling of the Silurian–Devonian granitoids in the Chinese Altai.

关键词： granitoids crustal recycling Ordovician wedge sediments partial melting Nd-Hf decoupling Chinese Altai geochemistry

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Altitude-dependent distribution of 137Cs in the environment:a case study of Aragats massif, Armenia

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Acta Geochimica 2020年第1期39卷 127-138页

作者： Konstantin Pyuskyulyan stephen P.LaMont Vovik Atoyan Olga Belyaeva Nona Movsisyan Armen Saghatelyan Armenian Nuclear Power Plant MetsamorArmenia Nuclear and Radiochemistry Los Alamos National LaboratoryLos AlamosUSA Radioecology Department Center for Ecological-Noosphere StudiesNAS RA.YerevanArmenia

This paper considers the distribution of technogenic 137Cs and naturally occurring radionuclides:238 U,232 Th and40 R concentrations in soils and 137Cs in atmospheric dry depositions by altitudinal belts of the Aragats mountain massif,Republic of *** soil samples were collected at altitudes from 1000 to 3200 *** the determination of geochemical variability,two soil sampling campaigns were *** dry depositions were sampled from five stations at1100-3200 m collected onto organic fiber filters between June and December 2016.137Cs activity was measured using a high-purity Germanium detector coupled to a multichannel analyzer(Canberra).Results indicated that specific activity of 137Cs in soils at 1000 m is495-528 Bq m^-2,andat3200 mis10,500-11,470 Bq m^-*** correlation observed for 137Cs versus naturally occurring radionuclides,which varies in distribution by *** activities of 137Cs in dry atmospheric depositions varies from 1.06 at 846 m to2.37 Bq m^-2 per quarter at 3200 m and increases as the altitude *** of 137Cs in soil and dry atmospheric deposition correlated significantly,and 137Cs activity in soils and atmospheric dry depositions decrease as the absolute altitude *** 50-year effective dose from exposure to 137Cs fallout varies with altitude from 0.007 to 1.42 m Sv.

关键词： 137Cs Distribution by altitude Naturally occurring radionuclides Topsoil Dry atmospheric depositions Gamma radiation Mountain regions

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