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Nontraditional manufacturing technique——Nano machining technique based on SPM

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Science China(Physics,Mechanics & Astronomy) 2004年第Z1期47卷 51-58页

作者： DONG Shen YAN Yongda SUN Tao LIANG Yingchun CHENG Kai po box 413 Harbin Institute of Technology Harbin 150001 China PO Box 413 Harbin Institute of Technology Harbin 150001 China PO Box 413 Harbin Institute of Technology Harbin 150001 China PO Box 413 Harbin Institute of Technology Harbin 150001 China PO Box 413 Harbin Institute of Technology Harbin 150001 China

Nano machining based on SPM is a novel, nontraditional advanced manufacturing technique. There are three main machining methods based on SPM, i.e. single atom manipulation, surface modification using physical or chemical actions and mechanical scratching. The current development of this technique is summarized. Based on the analysis of mechanical scratching mechanism, a 5 μm micro inflation hole is fabricated on the surface of inertial confinement fusion (IGF) target. The processing technique is optimized. The machining properties of brittle material, single crystal Ge, are investigated. A micro machining system combining SPM and a high accuracy stage is developed. Some 2D and 3D microstructures are fabricated using the system. This method has broad applications in the field of nano machining.

关键词： SPM, nano machining, diamond tip, microstructures, inertial confinement fusion (ICF)

Vibration Performance, Stability and Energy Transfer of Wind Turbine Tower via Pd Controller

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Computers, Materials & Continua 2020年第8期64卷 871-886页

作者： Y.S.Hamed Ayman A.Aly B.Saleh Ageel F.Alogla Awad M.Aljuaid Mosleh M.Alharthi Department of Mathematics and Statistics Faculty of ScienceTaif UniversityTaifPO Box 888Saudi Arabia Department of Physics and Engineering Mathematics Faculty of Electronic EngineeringMenoufia UniversityMenoufPO Box 32952Egypt Department of Mechanical Engineering College of EngineeringTaif UniversityTaifPO Box 888Saudi Arabia Department of Mechanical Engineering Faculty of EngineeringAssiut UniversityAssiutPO Box 71516Egypt Department of Electrical Engineering College of EngineeringTaif UniversityTaifPO Box 888Saudi Arabia

In this paper,we studied the vibration performance,energy transfer and stability of the offshore wind turbine tower system under mixed *** method of multiple scales is utilized to calculate the approximate solutions of wind turbine *** proportional-derivative controller was applied for reducing the oscillations of the controlled *** the controller to single degree of freedom system equation is responsible for energy transfers in offshore wind turbine tower *** steady state solution of stability at worst resonance cases is studied and *** offshore wind turbine system behavior was studied numerically at its different parameters ***,the response and numerical results were obtained and *** stability is also analyzed using technique of phase plane and equations of frequency *** addition,the numerical results and comparison between analytical and numerical solutions were obtained with MAPLE and MATLAB algorithms.

关键词： Vibration control stability offshore wind turbine system energy transfer

Trade-offs between wood production and forest grouse habitats in two regions with distinctive landscapes

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Forest Ecosystems 2020年第2期7卷 274-289页

作者： Helena Haakana Esa Huhta Hannu Hirvelä Tuula Packalen Natural Resources Institute Finland(Luke) PO Box 2FI-00791 HelsinkiFinland Natural Resources Institute Finland(Luke) PO Box 16FI-96301 RovaniemiFinland Natural Resources Institute Finland(Luke) PO Box 68FI-80101 JoensuuFinland.

Background:Forest management affects the viability of forest grouse populations,causing alterations to habitat *** the regional level,common targets for wood harvesting and safeguarding of specific habitats are negotiated between various *** potential trade-offs between forest grouse habitats and wood production in the region could support resource-smart decision ***:In this paper,we compiled trade-off curves represented as production possibility frontiers demonstrating the relationship between forest grouse habitat area and wood removal,using a Finnish forestry dynamics model and the Finnish Multi-Source National Forest *** the modelling of forest grouse habitats,a landscape-level occurrence model based on nationwide wildlife triangle census data was *** alternative forest scenarios in terms of wood removal were compiled for two study areas in Finland representing two different landscape *** and conclusions:Results showed that impacts on forest grouse habitats were *** the southern study area,increasing the roundwood harvesting rate affected grouse habitats more strongly as forests were already fragmented for other land uses and became more spruce-dominated over *** the maximum sustainable removal rate was implemented,predicted grouse habitat area was 55%less than in a no-removal *** the eastern study area,a more heavily forested region,the decrease was far lower at 22%.Scenario results were also compared to levels of recorded(business as usual)wood removal and that envisaged by valid regional forestry programmes,and their sustainability in terms of grouse habitat area was *** production possibility frontiers calculated in this study support the evaluation of the loss of suitable habitat caused by different wood harvesting rates,or vice versa,the economic cost of increasing habitat areas.

关键词： Forest grouse Forest landscape Habitat model Production possibilities frontier Scenario analyses Wood production

Measurement of ^2H（^8Li, ^9Be）n Reaction Relevant to Primordial Nucleosynthesis

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Chinese Physics Letters 2005年第9期22卷 2219-2221页

作者：曾晟柳卫平李志宏白希祥颜胜权王宝祥连刚苏俊 China Institute of Atomic Energy PO Box 275(46) Beijing 102413

The angular distribution of the ^2H（^8Li, ^9Be）n （ground state） reaction, important to primordial nucleosynthesis in the inhomogeneous model, has been measured at E = 8.1 MeV using a secondary ^8Li beam. Cross section of this reaction was determined to be 9.0 4±3.4 mb. According to the cross section, the astrophysical S-factor was calculated to be 272 4±103 keV b. It is shown that ^2H（8^Li, ^9Be）n （ground state） reaction is important for creating 9Be, but less important for destroying aLl in primordial nucleosynthesis.

关键词： CD GIRAFFE FWHM

Computational Investigation of InxGa1-xN/InN Quantum-Dot Intermediate-Band Solar Cell

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Chinese Physics Letters 2011年第1期28卷 208-211页

作者： DENG Qing-Wen WANG xiao-Liang YANG Cui-Bai XIAO Hong-Ling WANG Cui-Mei YIN Hai-Bo HOU Qi-Feng BI Yang LI Jin-Min WANG Zhan-Guo HOU Xun Materials Science Center Institute of Semiconductors Chinese Academy of Sciences PO Box 912 Beijing 100083 Key Laboratory of Semiconductor Materials Science Institute of Semiconductors Chinese Academy of SciencesPO Box 912 Beijing 100083 ISCAS-XJTU Joint Laboratory of Functional Materials and Devices for Informatics PO Box 912 Beijing 100083

An Inx Ga1_xN/lnN quantum-dot intermediate-band solar cell is calculated by means of solving the Schrodinger equation according to the Kronig-Penney model. Based on particular assumptions, the power conversion efficiency is worked out. The results reveal that the InxGa1- xN/InN quantum-dot intermediate-band solar cell manifests much larger power conversion efficiency than that of p-n junction solar cells, and the power conversion efficiency strongly depends on the size of the quantum dot and the interdot distance.

关键词： GALLIUM (Metal) QUANTUM dots SOLAR cells INTERMEDIATES (Chemistry) SCHRODINGER equation ENERGY conversion

Cathodoluminescence of Yellow and Blue Luminescence in Undoped Semi-insulating GaN and n-GaN

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Chinese Physics Letters 2011年第3期28卷 184-187页

作者： HOU Qi-Feng WANG Xiao-Liang XIAO Hong-Ling WANG Cui-Mei YANG Cui-Bai YIN Hai-Bo LI Jin-Min WANG Zhan-Guo Materials Science Center Institute of SemiconductorsChinese Academy of SciencesPO Box 912Beijing 100083 Key Laboratory of Semiconductor Materials Science Chinese Academy of SciencesPO Box 912Beijing 100083

Yellow and blue luminescence in undoped GaN layers with different resistivities are studied by *** yellow and blue luminescence bands are observed in semi-insulating GaN,while in n-GaN the yellow luminescence and blue luminescence bands are very *** stronger yellow and blue luminescences in semi-insulating GaN are correlated to the higher edge-type dislocation *** scanning cathodoluminescence image reveals strong defect-related luminescence at the grain boundaries where the dislocations *** is found that the relative intensity of the blue luminescence band to the yellow luminescence band increases with the cathodoluminescence beam energies and is larger in n-GaN with a lower density of edge-type *** approximately 3.35eV shoulder next to the near-band-edge peak is observed in n-GaN but not in semi-insulating GaN.A redshift of the near-band-edge peak with cathodoluminescence beam energy is observed in both samples and is explained by internal absorption.

关键词： GaN luminescence yellow

Rangeland water requirement satisfaction index under rainfall variability and predicting future rainfall scenarios: implication for availability of feed resources

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Ecological Processes 2017年第1期6卷 264-272页

作者： Hassen M.Ahmed Zewdu K.Tessema Adugna Tolera Diriba Korecha School of Animal and Range Sciences College of Agriculture and Environmental SciencesPO Box 138Dire DawaEthiopia School of Animal and Range Sciences Hawassa UniversityPO Box 222HawassaEthiopia Famine Early Warning Systems Network PO Box 1090Addis AbabaEthiopia School of Animal and Range Sciences College of Agriculture and Environmental SciencesHaramaya UniversityPO Box 1632Dire DawaEthiopia

Introduction:Rangeland ecosystems provide multiple ecosystem services,including feed resources for wild and domestic herbivores in semi-arid ***,under the ever increasing environmental changes,the impact of rainfall variability on the productivity and vegetation dynamics of rangelands are the great challenges that pastoral community are facing *** a result,the potentials of most rangelands in semi-arid ecosystems affect the ***,we studied the interconnections between the long-term rainfall variation and the rangeland Water Requirement and Satisfaction Index(WRSI)in Mieso,Jigjiga,and Shinile districts under pastoral conditions of ***:The base period rainfall data(1984–2015)was obtained from the National Meteorological Agency of Ethiopia,whereas the future rainfall trend was predicted using MarkSim software(Representative Concentration Pathways 4.5 GHG concentration trajectory).Mann-Kendall’s statistical tests,coefficient of variation,LEAP software(version 2.61),and Minitab Software(version 15)were used to assess the relationship between rangeland WRSI and long-term rainfall ***:The result indicated that mean annual rainfall anomaly had strong positive correlation with rangeland WRSI in Mieso(Ppositive association(P<0.001)with rangeland WRSI,especially in Jigjiga and Shinile pastoral *** base period rainfall as well as the predicted annual rainfall showed variability in amount and distribution in all studied districts in pastoral areas of ***:The mean annual rainfall anomaly is correlated with the rangeland ***,the future rainfall trend analysis indicated that variability of rainfall would be expected in between the years 2020–2049,2040–2069,and 2070–***,the future rainfall variability would limit future rangeland WRSI under pastoral conditions of Ethiopia.

关键词： LEAP software Pastoralist Rangeland water requirement Trend analysis

Current Trend in Synthesis,post-Synthetic Modifications and Biological Applications of Nanometal-Organic Frameworks(NMOFs)

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Chinese Journal of Chemistry 2019年第4期37卷 378-404页

作者： Ebenezer Baa Gary M.Watkins Rui.W.Krause Derek.N.Tantohb Department of Chemistry Rhodes UniversityPO Box 94Grahamstown6140South Africa Department of Applied Chemistry University of JohannesburgPO Box 524Auckland Park2006South Africa

Since the early reports of MOFs and their interesting properties,research involving these materials has grown wide in scope and *** synthetic approaches have ensued in view of obtaining materials with optimised properties,the extensive scope of application spanning from energy,gas sorption,catalysis biological applications has meant exponentially evolved over the *** far-reaching synthetic and PSM approaches and porosity control possibilities have continued to serve as a motivation for research on these *** respect to the biological applications,MOFs have shown promise as good candidates in applicati ons involving drug delivery,BioMOFs,sensing,imaging amongst *** being a while away from successful entry into the market,observed results in sensing,drug delivery,and imaging put these materials on the spot light as candidates poised to usher in a revolution in *** this regard,this review article focuses current approaches in synthesis,post functionalization and biological applications of these materials with particular attention on drug delivery,imaging,sensing and BioMOFs.

关键词： Current Trend post-Synthetic Modifications Nanometal-Organic Frameworks(NMOFs)

Compression curve analysis and compressive strength measurement of brittle granule beds in lieu of individual granule measurements

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Particuology 2016年第6期14卷 60-68页

作者： Matti Jairvelainen Aaretti Kaleva Annikka Kaitajairvi ,Jarmo Laakso Ulla Kanerva Erkki Levanen Department of Materials Science Tampere University of Technology PO Box 589 FIN-33101 Tampere Finland VTT Technical Research Centre of Finland Sinitaival 6 PO Box 1300 FI33101 Tampere Finland

powders in granulated form are used in various processes to facilitate convenient usage. The durability of the formed granules is a crucial parameter, typically evaluated by the compressive strength of the gran- ules. However, especially for granules with a diameter in the order of tens of microns, statistically relevant testing of individual granules is not a feasible alternative, and in such cases uniaxial bed compression is required. There has not been consensus on whether uniaxial compression of a granule bed can be used to study the fracture of micron size or brittle granules. In our case study of a bed of sintered kaolinite granules with diameters under 100 μm, we show how the compressive strength of individual granules can be obtained from the compressive measurement of the entire bed by plotting the relative density versus the logarithmic pressure scale. We compressed the kaolinite powder with different loads; microscopy confirmed that below the ana- lyzed strength the granules are intact, though the granules start to fracture in the curved region on the compression curve. We found that angle-fitting can be used to locate the average compressive strength on the compression curve and to follow the evolution of strength with sintering temperature. The experi- ments in unison demonstrate that compression curve analysis is applicable for strength analysis of brittle granules.

关键词： GranuleMechanical characterization Pressing Compressive strength Sintering Compression curves