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Taiwan Yushan Snowfall Activity and Its Association with Atmospheric Circulation from 1979 to 2009

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Advances in Atmospheric Sciences 2011年第6期28卷 1423-1432页

作者：蔡梨敏刘广英王自发 Graduate University of the Chinese Academy of Sciences institute of Atmospheric physics Chinese Academy of Sciences Graduate institute of earth Sciences Chinese Culture University

Yushan is the most famous location for snow in Taiwan Willie snowIali in the subtropical zone is rare. When it is snowing in Yushan, people are experiencing unusually cold and wet weather elsewhere in Taiwan. In this study, Yushan snowfall activity from 1979 to 2009 and the related atmosphere circulation were examined with the Taiwan Central Weather Bureau＇s Yushan weather station observations and the National Centers for Environmental Prediction/Department of Energy （NCEP/DOE） reanalysis atmospheric data. To provide a quantitative measure of snowfall events, a snowfall activity index （SAI） was defined in this study. The time series of yearly SAIs shows that Yushan snowfall activity for an active year, such as 1983 （SAI =39 153） was ~118 times larger than for an inactive year, such as 1999 （SAI=331）. Our analyses show that snowfall activity is closely related to the position of the East Asian Trough （EAT） and the strength of the West Pacific High （WPH）. In active years, when the EAT shifted eastward and the strength of WPH increased, an anomalous anticyclone occurred in the West Pacific. This anticyclone introduced anomalous southwesterly flows along the southeastern cost of China's Mainland and over Taiwan, resulting in a wetter-than-normal atmosphere that favored snowfall. Alternatively, in inactive years, a drierhan-normal atmosphere resulted in sluggish snowfall seasons.

关键词： Yushan snowfall activity atmospheric circulation

Two decades of fire activity over the PEEX domain:a look from space,with contribution from models and ground-based measurements

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Big earth Data 2024年第2期8卷 350-396页

作者： Larisa Sogacheva Timo H.Virtanen Anu-Maija Sundström Pekka Kolmonen Mikhail Sofiev Hanna K.Lappalainen Antti Arola Finnish Meteorological institute Climate Research ProgrammeHelsinkiFinland Finnish Meteorological institute Space and Earth Observation CentreHelsinkiFinland institute for Atmospheric and earth System Research/physics Faculty of ScienceUniversity of HelsinkiHelsinkiFinland

It has been suggested that forest fires will become more frequent/intense with changing climate,which would increase aerosol/gas emissions into the atmosphere.A better under-standing of the relations between meteorological conditions,fires,and fire emissions will help estimate the climate response via forest *** this study,we use ERA5 meteor-ological products,including temperature,precipitation,and soil moisture,to explain the frequency of forest fires and the amount of radiant energy released per time unit by burning vegetation(fire radiative power,FRP).We explore the relation-ships between satellite-retrieved fire products and aerosol properties(aerosol optical depth,AOD),carbon monoxide(CO),formaldehyde(HCHO),and nitrogen dioxide(NO_(2))con-centrations over the PEEX domain,which covers different vegetation zones(***/grasslands,forest,arctic tun-dra)of Pan-Eurasia and *** analyse the concentrations of black carbon and absorbing organic carbon using groundbased AErosol RObotic *** analysis covers the months of May to August from 2002 to *** show posi-tive temperature trends in the Northern zone(>65°N)in June and August(1.56°C and 0.64°C,respectively);all statistically significant trends for precipitation and soil moisture are *** can explain increased fire activity in Siberia over the recent years(2019-2022).Over the whole PEEX domain,FC and FRP trends remain insignificant or negative;a decrease in AOD may address those negative *** show that intrasummer variations exist for cropland/grassland fires,which occur most often in May and August,while Siberian forest fires occur more often in July and *** show that CO concentration has been gradually decreasing in the last two decades in May and *** trends are negative in May,June,and over summer for all regions,in July in Europe,China,the Southern zone(<55°N),and the PEEX *** trends are not significant in all ***_(2)trends are positive in May and

关键词： PEEX wild fires satellite trend enhancement ratios

Luminescence and Energy Transfer Properties of Ca2Gd8(SiO4)6O2∶A(A=Pb2+, Tm3+)Phosphors

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Journal of Rare earths 2004年第6期22卷 825-828+7页

作者：韩秀梅林君 Key Laboratory of Rare earth Chemistry and physics Changchun Institute of Applied Chemistry Chinese Academy of SciencesKey Laboratory of Rare Earth Chemistry and Physics Changchun Institute of Applied Chemistry Chinese Academy of Sciences Changchun 130022 China Changchun 130022 China institute of New Materials North East University Qinhuangdao 066004 China

Ca2Gd8（SiO4）6O2∶ A(A=Pb2+, Tm3+)phosphors were prepared through the sol-gel process. X-ray diffraction（XRD）, scanning electron microscopy（SEM）and photoluminescence spectra were used to characterize the resulting phosphors. The results of XRD indicate that the phosphors crystallized completely at 1000 ℃. SEM study reveals that the average grain size is 300～1000 nm. In Ca2Gd8（SiO4）6O2∶Tm3+ phosphors, the Tm3+ shows its characteristic blue emission at 456 nm（1D2—3F4）upon excitation into its 3H6—1D2（361 nm）, with an optimum doping concentration of 1mol% of Gd3+ in the host lattices. In Ca2Gd8（SiO4）6O2∶Pb2+, Tm3+ phosphors, excitation into the Pb2+ at 266 nm（1S0—3P1）yields the emissions of Gd3+ at 311 nm（6P—8S）and Tm3+ at 367 nm（1D2 —3H6）and 456 nm（1D2—3F4）, indicating that energy transfer processes of Pb2+—Gd3+ and Pb2+—Tm3+ have occurred in the host lattices.

关键词： silicate oxyapatite luminescence Tm3+ Pb2+ energy transfer rare earths

Integrated modeling of fracturing-flowback-production dynamics and calibration on field data:Optimum well startup scenarios

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Petroleum Science 2023年第4期20卷 2202-2231页

作者： S.A.Boronin K.I.Tolmacheva I.A.Garagash I.R.Abdrakhmanov G.Yu Fisher A.L.Vainshtein P.K.Kabanova E.V.Shel G.V.Paderin A.A.Osiptsov Skolkovo institute of Science and Technology(Skoltech) Russia LLC Gazpromneft Science and Technology Center Russia The Schmidt institute of physics of the earth of the Russian Academy of Sciences MoscowRussia

We aim at the development of a general modelling workflow for design and optimization of the well flowback and startup operation on hydraulically fractured *** flowback model developed earlier by the authors is extended to take into account several new fluid mechanics factors accompanying flowback,namely,viscoplastic rheology of unbroken cross-linked gel and coupled“fracture-reservoir”numerical submodel for influx from rock *** also developed models and implemented new geomechanical factors,namely,(i)fracture closure in gaps between proppant pillars and in proppant-free cavity in the vicinity of the well taking into account formation creep;(ii)propagation of plastic deformations due to tensile rock failure from the fracture face into the fluid-saturated *** carried out parametric calculations to study the dynamics of fracture conductivity during flowback and its effect on well production for the set of parameters typical of oil wells in Achimov formation of Western Siberia,*** first set of calculations is carried out using the flowback model in the reservoir linear flow *** is obtained that the typical length of hydraulic fracture zone,in which tensile rock failure at the fracture walls occurs,is *** the range of rock permeability in between 0.01 mD and 1 D,we studied the effect of non-dimensional governing parameters as well as bottomhole pressure drop dynamics on oil *** obtained a map of pressure drop regimes(fast,moderate or slow)leading to maximum cumulative oil *** second set of parametric calculations is carried out using integrated well production modelling workflow,in which the flowback model acts as a missing link in between hydraulic fracturing and reservoir commercial *** evaluated quantitatively effects of initial fracture aperture,proppant diameter,yield stress of fracturing fluid,pressure drop rate and proppant material type(ceramic and sand)on long-term well product

关键词： Fracture cleanup Flowback Tensile rock failure Fracture closure Proppant embedment Proppant pack compaction

Hugoniot equation of state of olivine and its geodynamic implications

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Science China earth Sciences 2016年第3期59卷 619-625页

作者： HUANG Xiao Ge YUAN Xian Hao CHEN Zu An LIU Fu Sheng BAI Wu Ming Key Laboratory of earth and Planetary physics Institute of Geology and Geophysics Chinese Academy of Sciences institute of High Temperature and High Pressure physics Key Laboratory of Advanced Technologies of Materials Ministry of Education of China Southwest Jiaotong University

Large olivine samples were hot-pressed synthesized for shock wave experiments. The shock wave experiments were carried out at pressure range between 11 and 42 GPa. Shock data on olivine sample yielded a linear relationship between shock wave velocity D and particle velocity u described by D=3.56(?0.13)+2.57(?0.12)u. The shock temperature is determined by an energy relationship which is approximately 790°C at pressure 28 GPa. Due to low temperature and short experimental duration, we suggest that no phase change occurred in our sample below 30 GPa and olivine persisted well beyond its equilibrium boundary in metastable phase. The densities of metastable olivine are in agreement with the results of static compression. At the depth shallower than 410 km, the densities of metastable olivine are higher than those of the PREM model, facilitating cold slab to sink into the mantle transition zone. However, in entire mantle transition zone, the shock densities are lower than those of the PREM model, hampering cold slab to flow across the "660 km" phase boundary.

关键词： Hugonite density Shock temperature Olivine Mantle transition zone

Synthesis and Luminescence Properties of Ternary Europium Complexes inTitania Matrix in the Presence of Dimethylformamide by a Sol-Gel Process

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Journal of Rare earths 1999年第4期17卷 259-262页

作者：符连社张洪杰孟庆国王淑彬杨魁跃倪嘉缵 Key Laboratory of Rare earth Chemistry and physics Changchun Institute of Applied Chemistry Chinese Academy of Sciences Changchun 130022 China

In-situ synthesis of ternary europium complex with thenoyltrifluoacetone (TTA) and 1,10-phenanthroline (phen) in titania matrix in the presence of dimethylformamide (DMF) by a sol-gel process was described, which was confirmed by the luminescence excitation spectra and infrared spectra. The titania gel that contains europium complex exhibits Eu3+ characteristic emission bands and presents a longer fluorescence lifetime than the pure complexes dissolved in ethanol solution. The concentration effect on the luminescence intensity was also investigated.

关键词： rare earths sol-gel method in-situ synthesis titania dimethylformamide

Preliminary investigation on electrothermal instabilities in early phases of cylindrical foil implosions on primary test stand facility

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Chinese physics B 2019年第2期28卷 352-357页

作者： Guanqiong Wang Delong Xiao Jiakun Dan Yang Zhang Ning Ding Xianbin Huang Xiaoguang Wang Shunkai Sun Chuang Xue Xiaojian Shu institute of Applied physics and Computational Mathematics institute of Fluid physics Chinese Academy of Engineering Physics

Recent experiments on the implosions of 15-mm long and 2-μm thick aluminum liners having a diameter of 12.8 mm have been performed on the primary test stand(PTS) facility. The stratified structures are observed as alternating dark and light transverse stripes in the laser shadowgraph images. These striations perpendicular to the current flow are formed early in the implosion, i.e., at the stage when the bulk of the material mass was almost at rest. A two-dimensional(2 D)magnetohydrodynamics(MHD) code is employed to simulate the behavior of liner dynamics in the early phases. It is found that the striations may be produced by the electrothermal instability(ETI) that results from non-uniform Joule heating due to the characteristic relation between the resistivity and the temperature. In 2 D simulations, the stratified structures can be seen obviously in both density and temperature contours as the liner expands rapidly. By analyzing instability spectrum, the dominant wavelengths of the perturbations are 8.33 μm–20.0 μm, which agree qualitatively with the theoretical *** is also interesting to show that ETI provides a significant seed to the subsequent magneto Rayleigh–Taylor(MRT)instability.

关键词： Z-pinch electrothermal instability magnetohydrodynamics(MHD) simulations

Orientation dependence of structural transition in fcc Al driven under uniaxial compression by atomistic simulations

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Chinese physics B 2011年第4期20卷 391-396页

作者：李莉邵建立段素青梁九卿 institute of Theoretical physics and Department of physics Shanxi University institute of Applied physics and Computational Mathematics

By molecular dynamics simulations employing an embedded atom method potential, we have investigated structural transformations in single crystal A1 caused by uniaxial strain loading along the [001], [011] and [111] directions. We find that the structural transition is strongly dependent on the crystal orientations. The entire structure phase transition only occurs when loading along the [001] direction, and the increased amplitude of temperature for [001] loading is evidently lower than that for other orientations. The morphology evolutions of the structural transition for [011] and [111] loadings are analysed in detail. The results indicate that only 20% of atoms transit to the hcp phase for [011] and [111] loadings, and the appearance of the hcp phase is due to the partial dislocation moving forward on {lll}fcc family. For [011] loading, the hcp phase grows to form laminar morphology in four planes, which belong to the {111}fcc family; while for [111] loading, the hcp phase grows into a laminar structure in three planes, which belong to the {111}fcc family except for the （111） plane. In addition, the phase transition is evaluated by using the radial distribution functions.

关键词： single crystal Al molecular dynamics simulations uniaxial compression phase transition

A comparison study of summer-time synoptic-scale waves in South China and the Yangtze River basin using the TRMM Multi-Satellite Precipitation Analysis daily product

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Science China earth Sciences 2008年第1期51卷 114-122页

作者： Fu Rong Hu Liang Gu GuoJun Li YaoDong institute of Atmospheric physics Chinese Academy of Sciences Beijing 100029 China School of earth and Atmospheric Sciences Georgia Institute of Technology Atlanta GA 30332 USA Goddard earth Sciences and Technology Center University of

Summer-time synoptic-scale waves in South China and the Yangtze River basin are quantified and compared by means of analyzing the 6-year (1998–2004) TRMM Multi-Satellite Precipitation Analysis (TMPA) daily product. A... 详细信息

关键词： TRMM 3-dimensional spectrum analysis synoptic-scale waves South China Yangtze River basin