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Changes in sea ice kinematics in the Arctic outflow region and their associations with Arctic Northeast Passage accessibility

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Acta Oceanologica Sinica 2019年第8期38卷 101-110页

作者： Dawei Gui Xiaoping Pang Ruibo Lei Xi Zhao Jia Wang Chinese Antarctic Center of Surveying and Mapping Wuhan University Wuhan 430079 China MNR Key Laboratory for Polar Science Polar Research Institute of China Shanghai 200136 China National Oceanic and Atmospheric Administration Great Lakes Environmental Research Laboratory Ann Arbor 48108-9719 USA

Amplification of climate warming in the Arctic is causing a dramatic retreat of sea ice, which means the Arctic sea routes are becoming increasingly accessible. This study used a satellite-derived sea ice motion product to quantify the kinematic features of sea ice in the Arctic outflow region which specially referred to the Fram Strait and to the north of the Northeast Passage(NEP). An observed trend of increased southward sea ice displacement from the central Arctic to the Fram Strait indicated enhancement of the Transpolar Drift Stream(TDS). In the regions to the north of the NEP, the long-term trend of northward sea ice speed in the Kara sector was +0.04 cm/s per year in spring. A significant statistical relationship was found between the NEP open period and the northward speed of the sea ice to the north of the NEP. The offshore advection of sea ice could account for the opening of sea routes by 33% and 15% in the Kara and Laptev sectors, respectively. The difference in sea level pressure across the TDS,i.e., the Central Arctic Index(CAI), presented more significant correlation than for the Arctic atmospheric Dipole Anomaly index with the open period of the NEP, and the CAI could explain the southward displacement of sea ice toward the Fram Strait by more than 45%. The impact from the summer positive CAI reinforces the thinning and mechanical weakening of the sea ice in the NEP region, which improves the navigability of the NEP.

关键词： sea ice Arctic Northeast Passage Transpolar Drift Stream atmospheric circulation indices

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Geochemical contamination in the mine affected soil of Raniganj Coalfield——A river basin scale assessment

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Geoscience Frontiers 2018年第5期9卷 1577-1590页

作者： Abhijit Manna Ramkrishna Maiti Department of Geography and Environment Management Vidyasagar University

The study aimed to assess the heavy metals(K, Ca, Ti, Cr, Mn, Fe, Ni, Cu, Zn, As, Pb, Sr, Zr) contamination in the soil of mine affected Singaran river basin and to analyse spatial variation in the contamination level considering 32 soil samples. Elemental analysis of soil samples has been performed through Energy Dispersive X-ray Analysis(EDX) to quantify the elemental concentration(mg kgà1). Heavy metal concentrations have been assessed through geo-accumulation index(Igeo) and enrichment factor(EF).indices showed soils have moderate accumulation of most of the metals with moderate enrichment of Sr,Zr, Zn, Cu and Ni. Soil contamination level assessment has been carried out using indices like Contamination Factor(CF), degree of contamination(C_(deg)), modified degree of contamination(m C_(deg)) and Pollution Load Index(PLI). CF shows moderate to considerable contamination by Sr, Zr, Ca, Cu, Mn, Zn and Ni. Mean indices values(m C_(deg)and PLI for the entire basin are 3.38 and 2.23 respectively) show low to moderate level of soil contamination. These indices result have been mapped and analysed in GIS platform to get spatial variation of pollution level. Opencast mines dominate middle catchment area and so is comparatively contaminated. Sample sites 11, 18 and 25 evidenced high values of all indices of pollution load. From the ecological standpoint Ecological Risk Factor(Er) and Potential Ecological Risk Index(RI) have been estimated to assess regional threat to native soil environment and it shows low ecological risk potential. Analysis shows that mine dominated soil of the entire Singaran basin is less contaminated in all respect but tends to the moderate contamination level at the mid-catchment area,especially by Sr, Zr, Zn, Cu and Ni.

关键词： Heavy metals Soil contamination Pollution indices Pollution load Ecological risk Singaran basin

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Estimating aboveground biomass using Pléiades satellite image in a karst watershed of Guizhou Province,Southwestern China

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Journal of Mountain Science 2018年第5期15卷 1020-1034页

作者： GUO Yin-ming NI Jian LIU Li-bin WU Yang-yang GUO Chun-zi XU Xin ZHONG Qiao-lian State Key Laboratory of Environmental Geochemistry Institute of Geochemistry Chinese Academy of Sciences Guiyang 550081 China Puding Karst Ecosystem Research Station Chinese Academy of Sciences Puding 562100 China University of Chinese Academy of Sciences Beijing 100049 China College of Chemistry and Life Sciences Zhejiang Normal University Jinhua 321004 China

Biomass in karst terrain has rarely been measured because the steep mountainous limestone terrain has limited the ability to sample woody *** observation, especially at high spatial resolution, is an important surrogate for the quantification of the biomass of karst forests and shrublands. In this study, an artificial neural network(ANN) model was built using Pléiades satellite imagery and field biomass measurements to estimate the aboveground biomass(AGB) in the Houzhai River Watershed, which is a typical plateau karst basin in Central Guizhou Province, Southwestern China. A back-propagation ANN model was also *** vegetation indices, two spectral bands of Pléiades imagery, one geomorphological parameter,and land use/land cover were selected as model inputs. AGB was chosen as an output. The AGB estimated by the allometric functions in 78 quadrats was utilized as training data(54 quadrats, 70%),validation data(12 quadrats, 15%), and testing data(12 quadrats, 15%). Data-model comparison showed that the ANN model performed well with an absolute root mean square error of 11.85 t/ha, which was 9.88%of the average AGB. Based on the newly developed ANN model, an AGB map of the Houzhai River Watershed was produced. The average predicted AGB of the secondary evergreen and deciduous broadleaved mixed forest, which is the dominant forest type in the watershed, was 120.57 t/ha. The average AGBs of the large distributed shrubland,tussock, and farmland were 38.27, 9.76, and 11.69 t/ha, respectively. The spatial distribution pattern ofthe AGB estimated by the new ANN model in the karst basin was consistent with that of the field investigation. The model can be used to estimate the regional AGB of karst landscapes that are distributed widely over the Yun-Gui Plateau.

关键词： Aboveground biomass Secondary karstforest Artificial neural network Vegetation indices Very high resolution satellite image

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Comparative study of otolith and sulcus morphology for stock discrimination of yellow drum along the Chinese coast

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Journal of Oceanology and Limnology 2019年第4期37卷 1430-1439页

作者： SONG Junjie ZHAO Bo LIU Jinhu CAO Liang DOU Shuozeng Key Laboratory of Marine Ecology and Environmental Sciences Institute of Oceanology Chinese Academy of Sciences Qingdao 266071 China Laboratory for Marine Ecology and Environmental Science Qingdao National Laboratory for Marine Science and Technology Qingdao 266071 China University of Chinese Academy of Sciences Beijing 100049 China Center for Ocean Mega-Science Chinese Academy of Sciences Qingdao 266071 China

Otolith morphology is widely used for fish stock identification. The sulcus, a structure on the medial side of the otolith, is an important feature in morphological analysis. This study was conducted to evaluate the feasibility of using sulcus morphology for stock identification and to compare its performance with commonly used otolith morphology analysis. Otoliths were collected and analyzed from three geographical groups (the Huanghe (Yellow) River estuary, HHE;the Jiaozhou Bay, JZB;and the Changjiang (Yangtze) River estuary, CJE) of yellow drum Nibea albiflora. The results show that the analysis of sulcus morphology based on shape indices (SIs), elliptic Fourier coefficients (EFc), and a combination of the two parameters identified stocks at overall classification rates of 51.0%, 72.5%, and 73.2%, respectively. These classification rates are similar to those obtained using otolith morphology analysis (57.0%, 73.8%, and 76.5% by SIs, EFc, and their combination, respectively). The findings suggest that sulcus morphology is comparable to the commonly used otolith morphology for identifying stocks of sciaenids, such as the yellow drum. For both otolith and sulcus morphology, EFc could identify the stocks more efficiently than SIs, while the combination of SIs and EFc was even better.

关键词： otolith sulcus shape indices elliptic Fourier analysis stock discrimination Nibea albiflora

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Effects of long-term warming on the aboveground biomass and species diversity in an alpine meadow on the Qinghai-Tibetan Plateau of China

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Journal of Arid Land 2020年第2期12卷 252-266页

作者： WEN Jing QIN Ruimin ZHANG Shixiong YANG Xiaoyan XU Manhou Taiyuan Normal University Jinzhong 030619China

Ecosystems in high-altitude regions are more sensitive and respond more rapidly than other ecosystems to global climate *** Qinghai-Tibet Plateau(QTP)of China is an ecologically fragile zone that is sensitive to global climate *** is of great importance to study the changes in aboveground biomass and species diversity of alpine meadows on the QTP under predicted future climate *** this study,we selected an alpine meadow on the QTP as the study object and used infrared radiators as the warming device for a simulation experiment over eight years(2011-2018).We then analyzed the dynamic changes in aboveground biomass and species diversity of the alpine meadow at different time scales,including an early stage of warming(2011-2013)and a late stage of warming(2016-2018),in order to explore the response of alpine meadows to short-term(three years)and long-term warming(eight years).The results showed that the short-term warming increased air temperature by 0.31℃and decreased relative humidity by 2.54%,resulting in the air being warmer and *** long-term warming increased air temperature and relative humidity by 0.19℃and 1.47%,respectively,and the air tended to be warmer and *** short-term warming increased soil temperature by 2.44℃and decreased soil moisture by 12.47%,whereas the long-term warming increased soil temperature by 1.76℃and decreased soil moisture by 9.90%.This caused the shallow soil layer to become warmer and drier under both short-term and long-term ***,the degree of soil drought was alleviated with increased warming *** the long-term warming,the importance value and aboveground biomass of plants in different families *** importance values of grasses and sedges decreased by 47.56%and 3.67%,respectively,while the importance value of weeds increased by 1.37%.Aboveground biomass of grasses decreased by 36.55%,while those of sedges and weeds increased by 8.09%and 15.24%,*** increase

关键词： climate warming long-term warming species diversity indices aboveground biomass soil microclimate correlation analysis alpine meadows

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Coarse woody debris and wood-colonizing fungi differences between a reserve stand and a managed forest in the Taborz region of Poland

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Journal of Forestry Research 2019年第3期30卷 1081-1091页

作者： Slwomir Pieeka Agata Sotnik Marta Damszel Zbigniew Sierota Department of Forestry and Forest Ecology Warmia and Mazury University in OlsztynPl.Lodzki 210-727 Olsztyn Poland Milomlyn Forest District Nadlesna 914-140 Milomlyn Poland Department of Entomology Phytopathology and Molecular DiagnosticsWarmia and Mazury University in Olsztyn Prawochen′skiego 1710-721 OlsztynPoland

The aim of this research was to evaluate the amount of woody debris (m3/ha) on the forest floor and the associated wood-colonizing fungi. The study was performed in the Taborz region, known for its Scots pine provenance experiments, against the background of a recently launched Polish legislation to protect the biodiversity on the forest floor in managed (harvested) stands. We investigated a managed stand (136-years-old) and the reserve stand ‘Sosna Taborska’(261-years-old). In the reserve stand, the mean volume of woody debris was six times higher than in the managed forests, i.e. 65 versus 11 m3/ha. In addition, in the reserve stand, the number of fungi taxa colonizing the dead wood was larger than in the managed stands, with a higher number of fruitbodies. Total fungal richness was higher in the reserve than in the managed stand, i.e. 28 versus 12 species. The dominant taxa at both sites were Fomitopsis pinicola and Fomes The aim of this research was to evaluate the amount of woody debris (m^3/ha) on the forest floor and the associated wood-colonizing fungi. The study was performed in the Taborz region, known for its Scots pine provenance experiments, against the background of a recently launched Polish legislation to protect the biodiversity on the forest floor in managed (harvested) stands. We investigated a managed stand (136-years-old) and the reserve stand ‘Sosna Taborska’(261-years-old). In the reserve stand, the mean volume of woody debris was six times higher than in the managed forests, i.e. 65 versus 11 m^3/ha. In addition, in the reserve stand, the number of fungi taxa colonizing the dead wood was larger than in the managed stands, with a higher number of fruitbodies. Total fungal richness was higher in the reserve than in the managed stand, i.e. 28 versus 12 species. The dominant taxa at both sites were Fomitopsis pinicola and Fomes fomentarius, although some taxa were only found in the reserve (e.g., Stereum hirsutum). The volume of woody debris as w

关键词： Coarse woody debris Fungi Managed (harvested) stands Reserve Sosna Taborska Reserve Forest indices

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Extracting mineral alteration information using WorldView-3 data

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Geoscience Frontiers 2017年第5期8卷 1051-1062页

作者： Yaqin Sun Shufang Tian Baogang Di School of Earth Science and Resources China University of Geosciences Beijing 100083 China

The multispectral commercial satellite-WorldView-3(WV-3) has the highest spatial, spectral and radiation resolutions among the satellites currently and can generate good data in the shortwave infrared(SWIR). The study area is located in the Pobei area of Xinjiang Uygur Autonomous Region, which is rich in mineral resources. The spectral analyses of some typical altered hydroxy-bearing, iron-bearing, and carbonate-bearing minerals could establish several Principal Component Analysis(PCA) models and mineral indices, using the visible and near infrared(VNIR) and the shortwave infrared(SWIR) subsystems of WV-3 data. In addition, the Spectral Angle Method and the spectrum index tool of ENVI software were used to extract the relevant alteration information. The WV-3 data is well suited for identifying hydroxy-bearing alteration with rich SWIR bands which distinguish Al-OH-bearing from MgOH-bearing alteration. Hence, this study provides a basis for the prediction of mineral resources in the Pobei area and sets the foundation for WV-3 data to be used as an important tool in extracting alteration information and prospecting practices.

关键词： WorldView-3 Alteration information Principal Component Analysis (PCA) Mineral indices Pobei Xinjiang

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Poling Effects of Dielectric and Optical Properties on Pb(Zn1/3Nb2/3)1-xTixO3 Crystal

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Journal of Rare Earths 2006年第Z1期24卷 166-168页

作者： Tu Chi Shun Wang Fu Tang Chien R R Hugo Schmidt V Chew L L Graduate Inst.of Applied Science and Engineering Fu Jen University Taipei 242 China Graduate Inst.of Applied Science and Engineering Fu Jen University Taipei 242 China Department of Physics Montana State University Bozeman MT 59717 USA Department of Physics Montana State University Bozeman MT 59717 USA Department of Mechanical Engineering National University of Singapore Singapore

Dipolar relaxation and dielectric/piezoelectric resonance in a (001)-cut Pb(Zn1/3Nb2/3)0.9Ti0.1O3 (PZNT10%) single crystal before and after electric (E)-field poling were presented. Dielectric permittivities were measured as functions of temperature, frequency and poling E-field strength. Frequency-dependent dielectric spectroscopy in the poled sample exhibits multiple piezoelectric resonances between 0.1 and 1 MHz, which can be described by the forced-damped-oscillator model. The resonant spectra show significant changes while phase transitions are taking place. The unpoled crystal shows almost no optical birefringence, indicating that the average structure symmetry is isotropic. Birefringence of the crystal is significantly enhanced by a prior E-field poling.

关键词： Pb(Zn1/3Nb2/3)1-xTixO3 dielectric permittivity phase transitions refractive indices

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3D-QSAR and docking studies of estrogen compounds based on estrogen receptor β

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Science China Chemistry 2009年第7期52卷 1042-1050页

作者： YANG XuShu WANG XiaoDong LUO Si JI Li QIN Liang LI Rong SUN Cheng WANG LianSheng State Key Laboratory of Pollution Control and Resources Reuse School of EnvironmentNanjing UniversityNanjing 210093China School of Pharmacy Nanjing Medical UniversityNanjing 210029China

Close attention has been paid to estrogen compounds because these chemicals may pose a serious threat to the health of humans and wildlife. Estrogen receptor (ER) exists as two subtypes, ERα and ERβ. The difference in amino acids sequence of the binding sites of ERα and ERβ might lead to a result that some synthetic estrogens and naturally occurring steroidal ligands have different relative affinities and binding modes for ERα and ERβ. In this investigation, comparative molecular similarity indices analysis (CoMSIA) was performed on 50 estrogen compounds binding ERβ to find out the structural relationship with the activities. We also compared two alignment schemes employed in CoMSIA analy-sis, namely, atom-fit and receptor-based alignment, with respect to the predictive capability of their respective models for structurally diverse data sets. The model with the significant correlation and the best predictive power (R2=0.961, qL 2OO=0.671, RP 2red=0.722) was achieved. The CoMSIA and docking results revealed the structural features related to an activity and provided an insight into molecular mechanisms of estrogenic activities for estrogen compounds.

关键词： estrogen receptor β 3D-QSAR docking comparative molecular similarity indices analysis (CoMSIA) prediction for activity molecular mechanisms

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Influences of soil moisture and salt content on loess shear strength in the Xining Basin, northeastern Qinghai-Tibet Plateau

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Journal of Mountain Science 2019年第5期16卷 1184-1197页

作者： FU Jiang-tao HU Xia-song LI Xi-lai YU Dong-mei LIU Ya-bin YANG You-Qing QI Zhao-xin LI Shu-xia Key Laboratory of Comprehensive and Highly Efficient Utilization of Salt Lake Resources Qinghai Institute of Salt Lakes Chinese Academy of Sciences Qinghai Provincial Key Laboratory of Geology and Environment of Salt Lakes University of Chinese Academy of Sciences Department of Geological Engineering Qinghai University College of Agriculture and Animal Husbandry Qinghai University

Moisture and salt content of soil are the two predominant factors influencing its shear strength. This study aims to investigate the effects of these two factors on shear strength behavior of loess in the Xining Basin of Northeast Qinghai-Tibet Plateau, where such geological hazards as soil erosion, landslides collapse and debris flows are widespread due to the highly erodible loess. Salinized loess soil collected from the test site was desalinized through salt-leaching in the laboratory. The desalinized and oven-dried loess samples were also artificially moisturized and salinized in order to examine how soil salinity affects its shear strength at different moisture levels. Soil samples prepared in different ways(moisturizing, salt-leaching, and salinized) were measured to determine soil cohesion and internal friction angle. The results show that salt-leaching up to 18 rounds almost completely removed the salt content and considerably changed the physical components of loess, but the soil type remained unchanged. As salt content increases from 0.00% to 12.00%, both the cohesion and internal friction angle exhibit an initial decrease and then increase with salt content. As moisture content is 12.00%, the salt content threshold value for both cohesion and internal friction angle is identified as 3.00%. As the moisture content rises to 16.0% and 20.00%, the salt content threshold value for cohesion is still 6.00%, but 3.00% for internal friction angle. At these thresholds soil shear strength is the lowest, below which it is inversely related to soil salinity. Beyond the thresholds, however, the relationship is positive. Dissimilar to salinity, soil moisture content exerts an adverse effect on shear strength of loess. The findings of this study can provide a valuable guidance on stabilizing the engineering properties of salinized loess to prevent slope failures during heavy rainfall events.

关键词： Salinized loess Desalinized loess Salt-leaching Shear strength indices Moisture content Salt content

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