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Distributions of crystals and gas bubbles in reservoir ice during growth period

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Water Science and Engineering 2011年第2期4卷 204-211页

作者： Zhi-jun LI Wen-feng HUANG Qing JIA Matti LEPPARANTA State Key Laboratory of Coastal and Offshore Engineering Dalian University of Technology Dalian 116024 P. R. China College of Water Conservancy and Hydropower Heilongjiang University Harbin 150086 P. R. China Department of Physics University of Helsinki Helsinki FI-00014 Finland

In order to understand the dominant factors of the physical properties of ice in ice thermodynamics and mechanics, in-situ observations of ice growth and decay processes were carried out. Two samplings were conducted in the fast and steady ice growth stages. Ice pieces were used to observe ice crystals and gas bubbles in ice, and to measure the ice density. Vertical profiles of the type and size of ice crystals, shape and size of gas bubbles, and gas bubble content, as well as the ice density, were obtained. The results show that the upper layer of the ice pieces is granular ice and the lower layer is columnar ice; the average crystal size increases with the ice depth and remains steady in the fast and steady ice growth stages; the shape of gas bubbles in the upper layer of ice pieces is spherical with higher total content, and the shape in the middle and lower layers is cylinder with lower total content; the gas bubble size and content vary with the ice growth stage; and the ice density decreases with the increase of the gas bubble content.

关键词： ice crystal gas bubble crystal structure porosity ice density

NiO_(x) Nanoparticle Synthesis by Chemical Vapor Deposition from Nickel Acetylacetonate

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Materials sciences and Applications 2011年第4期2卷 258-264页

作者： Pavel Moravec Jiri Smolik Helmi Keskinen Jyrki M.Makela Snejana Bakardjieva Valeri V.Levdansky Institute of Chemical Process Fundamentals AS CR PragueCzech Republic Department of Physics Tampere University of TechnologyTampereFinland Department of Physics and Mathematics University of Eastern FinlandKuopioFinland Institute of Inorganic Chemistry AS CR Husinec-RezCzech Republic A.V.Luikov Heat and Mass Transfer Institute National Academy of Sciences of BelarusMinskBelarus

Ni/NiO nanoparticles were synthesized by metal organics chemical vapor deposition of nickel acetylacetonate in an externally heated tube flow reactor at moderate temperatures, up to 500°C. Particle production and characteristics were studied by evaluating the effects of reactor temperature, precursor concentration, and flow rate through the reactor. In addition, two precursor decomposition methods were examined: thermal decomposition and reduction by hydrogen. Particle production was monitored with a scanning mobility particle sizer, and particle characteristics were studied using transmission electron microscopy, high resolution transmission electron microscopy, selected area electron diffraction, and energy dispersive spectroscopy. The presence of hydrogen in the reaction mixture influenced significantly both particle production and their characteristics.

关键词： Nickel Nanostructures MOCVD Hot Wall Tube Reactor Electron Diffraction

Air-Stable Dy(III)-Macrocycle Enantiomers:From Chiral to Polar Space Group

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CCS Chemistry 2022年第12期4卷 3762-3771页

作者： Zhenhua Zhu Chen Zhao Quan Zhou Shuting Liu Xiao-Lei Li Akseli Mansikkamäki Jinkui Tang State Key Laboratory of Rare Earth Resource Utilization Changchun Institute of Applied ChemistryChinese Academy of SciencesChangchun 130022 University of Chinese academy of sciences Beijing 100049 University of Science and Technology of China Hefei 230026 NMR Research Unit University of OuluOulu FI-90014

Magnetoelectric(ME)multiferroic materials have unique advantages in low-power and high-density information storage,because they can simultaneously display ferroelectricity and ***,research on how to construct air-stable highperformance ME single-molecule magnets(SMMs)is ***,by introducing homochirality while reducing molecular symmetry,two doubledecker Dy(III)enantiomers adopting the polar space group P2_(1) and exhibiting excellent thermal stability were *** displayed zero field SMM behavior with an anisotropy barrier(Ueff)of ca.100 cm^(−1).This work establishes a rational chemical design strategy for crystallizing SMMs in polar space groups and elucidates the direction for future research,that is,engineering small-size high-performance SMMs.

关键词： Dy(III)-macrocycle enantiomers chiral polar space group single-molecule magnets

A Synthesis of Energy Transition Policies in Finland and China

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Bulletin of the Chinese academy of sciences 2022年第1期36卷 40-44页

作者： GUO Wen PAN Jiaofeng LIANG Liting Jari KUUSISTO MA Yanran Institutes of Science and Development Chinese Academy of Sciences University of Chinese academy of sciences University of Vaasa Finland

Since 2017,Finland and China have been developing a future-oriented partnership based on mutual economic and business *** starting point for this work is the recognition of significant differences in size,culture,and political as well as economic systems between the two *** Sino-finnish cooperation in energy transition can provide a good example of mutually beneficial partnership where countries complement each other in terms of knowhow and *** paper brings together the main findings from the policy study on energy transition in Finland and *** aims to identify potential policy initiatives for expanding Sino-finnish cooperation towards green growth.

关键词： Energy Transition Policy Sino-finnish Cooperation

The Black-winged Monarch(Monarcha frater):Geographic variation,taxonomy,a"new"population,and an enduring mystery in migration

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Avian Research 2023年第3期14卷 467-477页

作者： Leo Joseph Julian Teh Paul Sweet Phil Gregory Australian National Wildlife Collection CSIRO National Research Collections AustraliaCanberra2601Australia American Museum of Natural History New YorkUSA Sicklebill Safaris TopazQueensland4885Australia

The Black-winged Monarch(Monarcha frater)inhabits low-mid elevation forests across New Guinea and far northeastern *** its four recognized subspecies,*** is migratory,breeding in tropical north-eastern Australia from approximately November–*** non-breeding range of ***,apart from some individuals overwintering in Australia,has been unknown for>100 *** from 194 New Guinean and Australian specimens and a literature review have not solved this mystery;the narrow latitudinal range of the intratropical migration may inhibit use of GPS loggers in resolving the migration *** work in central and western parts of southern New Guinea is *** data,however,revealed an essentially overlooked population in north-western New Guinea east of the Bird's Head Peninsula phenotypically indistinguishable from nominate *** of that *** genomic analysis of the complex will be largely done from toepad skin because frozen tissue samples for DNA analysis exist only of four individuals of what we suggest should be elevated to species rank as *** discuss how genomic analysis might distinguish among alternative taxonomic hypotheses of one,two or three *** suggest English names for what we consider to be three diagnosable taxa worth recognizing at species rank in this group:Arfak Monarch corresponding to ***(Bird's Head Peninsula and the“new”population of north-western New Guinea);Pearly Monarch for ***(Australia and still unknown non-breeding range),and Masked Monarch for ***(including kunupi,elsewhere in New Guinea).

关键词： Australia Migration monarch flycatcher Monarcha frater New Guinea Taxonomy

Experimental study on the effect of porosity on the uniaxial compressive strength of sea ice in Bohai Sea

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Science China(Technological sciences) 2011年第10期54卷 2429-2436页

作者： LI ZhiJun ZHANG LiMin LU Peng Matti LEPPARANTA LI GuangWei State Key Laboratory of Coastal and Offshore Engineering Dalian University of Technology Dalian 116024 China Department of Physics Helsinki University Helsinki FI-00014 Finland

For the abnormal ice condition in 2009-2010 winter, sea ice samples were collected in a tide ditch outside a port in the east coast of Liaodong Bay, and ice specimens were prepared. Experimental study was carried out with a temperature-control precision of 0.1℃, and 117 columnar-grained ice specimens were loaded along the direction parallel to ice surface under different test temperatures （-4, -7, -10, -13, -16℃） and strain rates ranging from 10^-6 to 10^-2 s^-1 within which the ductile region, duetile-brittle transition and brittle region are contained. The uniaxial compressive strengths, density and salinity of the ice specmens were measured. The results support the curved-surface relationship between the uniaxial compressive strength and porosity within a wide range of strain rate. The curved-surface relationship gives a quantitative description about the variations of the mechanical behavior transition point with ice porosity, and supplies a uniform mathematical representation of uniaxial compressive strength under different failure modes. Besides, it is deduced that abnormal ice condition in 2009-2010 winter will not result in a change of the uniaxial compressive strength of sea ice in Bohai Sea.

关键词： sea ice ice problems ice control compressive strength measurements parameter estimation

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多点位控制压边数值模拟研究

塑性工程学报 2002年第2期9卷 49-51,55页

作者：谭晶孙胜赵振铎山东大学(南校区)模具工程技术研究中心济南250061

板料冲压成形的主要缺陷是起皱和撕裂 ,当模具的几何形状确定后 ,压边力是关键的成形控制参数 ,它不仅是凸模行程或时间的函数 ,还应随压边位置的不同而变化。确定拉深过程中板料各部位所需压边力的变化规律 ,可实现压边力的优化控制 ,... 详细信息

板料冲压成形的主要缺陷是起皱和撕裂 ,当模具的几何形状确定后 ,压边力是关键的成形控制参数 ,它不仅是凸模行程或时间的函数 ,还应随压边位置的不同而变化。确定拉深过程中板料各部位所需压边力的变化规律 ,可实现压边力的优化控制 ,对复杂拉深件如汽车覆盖件的成形尤为有利。该文以非轴对称抛物面车灯反光罩为例 ,采用DYNAFORM软件对其成形过程进行了数值模拟。

关键词：压边力数值模拟有限元板料拉深成形多点位控制

On secondary new particle formation in China

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Frontiers of Environmental Science & Engineering 2016年第5期10卷 191-200页

作者： Markku Kulmala Tuukka Petaja Veli-Matti Kerminen Joni Kujansuu Taina Ruuskanen Aijun Ding Wei Nie Min HU Zhibin Wang Zhijun Wu Lin Wang Douglas R. Worsnop University of Helsinki P.O. Box 64 Helsinki 00014 Finland Joint Intemational Research Laboratory of Atmospheric and Earth System sciences (JirLATEST) Nanjing University and University of Helsinki Nanjing 210093 China Institute for Climate and Global Change Research Nanjing University Nanjing 210000 China State Key Joint Laboratory of Environmental Simulation and Pollution Control College of Environmental Sciences and Engineering Peking University Beijing 100871 China Max Planck Institute for Chemistry Hahn-Meimer-Weg 1 Mainz DE 55128 Germany Department of Environmental Science & Engineering Fudan University Shanghai 200433 China Aerodyne Research Inc. Billerica MA 01821 USA

Formation of new atmospheric aerosol particles is a global phenomenon that has been observed to take place in even heavily-polluted environments. However, in all environments there appears to be a threshold value of the condensation sink （due to pre-existing aerosol particles） after which the formation rate of 3 nm particles is no longer detected. In China new particle production has been observed at very high pollution levels （condensation sink about 0.1 s-1 ） m several megaclt es, including Beijing, Shanghai and Nanjing as well as in Pearl River Delta （PRD）. Here we summarize the recent findings obtained from these studies and discuss the various implications these findings will have on future research and policy.

关键词： Aerosol particles Heavily-polluted environments Condensation sink New particle production Megacities

Spatial Distribution of Hemlock Woolly Adelgid Induced Hemlock Mortality in the Southern Appalachians

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Open Journal of Forestry 2014年第5期4卷 492-506页

作者： Tuula Kantola Paivi Lyytikainen-Saarenmaa Robert N.Coulson Sheryl Strauch Maria D.Tchakerian Markus Holopainen Hannu Saarenmaa Douglas A.Streett Knowledge Engineering Laboratory Department of EntomologyTexas A&M UniversityCollege StationTXUSA Department of Forest sciences University of HelsinkiHelsinkiFinland SIB Labs School of ComputingUniversity of Eastern FinlandJoensuuFinland Alexandria Forestry Center USDA Forest ServiceSouthern Research StationPinevilleLAUSA

Hemlock woolly adelgid (Adelges Tsugae Annand, HWA) outbreaks are posing a major threat to eastern hemlock (Tsuga canadensis L. Carr.) and Carolina hemlock (Tsuga caroliniana Engelm.) forest landscapes in the eastern USA. As foundation species, hemlocks play a variety of functional roles in forest landscapes. These species usually occur as isolated canopies and mixed species in landscapes where variation in topography is extreme. Spatially explicit inventory information on HWA induced hemlock mortality at landscape scale does not exist. High resolution aerial imageries enable landscape scale assessment even at the individual tree level. Accordingly, our goal was to investigate spatial pattern and distribution of HWA induced hemlock mortality using a high resolution aerial image mosaic in the Linville River Gorge, Southern Appalachians, western North Carolina. Our study objectives were: 1) to detect dead trees within the Lower Linville River watershed;2) to estimate the area occupied by dead trees in the forest canopy surface;3) to investigate the relationship of dead hemlocks and topography;and 4) to define the spatial pattern of the dead trees. We found ca. 10,000 dead trees within the study area, occupying over 7 ha of the canopy surface with an average area of 36 m2 per dead tree. The density of the dead trees was higher in proximity to the Linville River, at higher elevations, and on northern and northwestern aspects. Spatial pattern of the dead trees was generally clustered at all spatial scales. We suggest that although the reduction in plant biomass resulting from herbivory within the landscapes is modest, impact of the clustered distribution of hemlock mortality, especially in the riparian zones, is noteworthy. Our analysis of the pattern of hemlock decline provides new means for projecting future impacts of HWA on the range of hemlock distribution in eastern North America.

关键词： Adelges Tsugae Eastern Hemlock Southern Appalachians Spatial pattern Topography Tree Mortality Tsuga