Fei Wang

Huaiyin Institute of Technology, Ch’ing-chiang, Jiangsu Sheng, China

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Publications (145)86.55 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: The longitudinal and cross sectional TEM images of sepiolite mineral nanofibers were prepared by cutting in the direction parallel and perpendicular to nanofibers, and the channel microstructure of sepiolite nanofibers was studied. The thermal insulation mechanism of sepiolite nanofibers was analyzed according to the diagrammatic sketch obtained from the above experimental method. The results showed that many discontinuously connected bending shape channels with about 23-26 nm in diameter existed in the center region of nanofibers, and many discontinuously connected irregular micropores and mesopores with the size of about 1-9 nm existed on the wall of nanofibers. The main reasons for the formation of channel microstructure in sepiolite nanofibers were their minerogenetic conditions and the interaction between acid and high-speed airflow in the process of nanofibers preparation, and bubbles in the hydrotherm played a significant role in the microstructure formation. The thermal insulation performance of sepiolite nanofibers could be attributed to obstructive and infrared radiative thermal insulation.
    Journal of Nanoscience and Nanotechnology 05/2014; 14(5):3937-42. · 1.15 Impact Factor
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    ABSTRACT: Nano zinc oxide with a high refractive index has good thermal reflection performance, hollow glass microspheres have good thermal reflection and insulation performance, and sepiolite nanofibers with many nanostructural pores have good thermal insulation performance. The dispensability of nano zinc oxide in coating materials was improved by optimizing surface silane coupling agent modification process, leading to the good thermal reflection performance. The thermal insulation performance was improved by hollow glass microspheres and sepiolite nanofibers. On this basis, the thermal insulation coating materials were prepared by exploring the effect of amount, complex mode, and other factors of the above three kinds of functional fillers on the thermal reflection and insulation performance of coating materials. The results showed that the surface modification effect of nano zinc oxide was the best when the silane coupling agent addition was 6%. The reflection and insulation performance of the coatings were the best when the additions of modified nano zinc oxide, hollow glass microspheres, and sepiolite nanofibers were 3%, 4%, and 4%, respectively. Compared with the control coating materials, the thermal insulation effect was improved obviously, which was evaluated by the -13.5 degrees C increase of maximum temperature difference between the upper and the lower surfaces.
    Journal of Nanoscience and Nanotechnology 05/2014; 14(5):3861-7. · 1.15 Impact Factor
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    ABSTRACT: Surface modification is used to regulate surface free energy of sepiolite with 3-glycidoxypropyltrimethoxysilanes (3-GPTMS), 3-methacryloxypropyltrimethoxysilanes (3-MAPTMS) and 3-mercaptopropyltrimethoxysilane (3-MPTMS). Through characterization by Fourier transform infrared spectroscopy, surface free energy, zeta potential and sedimentation measurements and infrared emissivity, it is found that the surface free energy of 3-MPTMS modified sepiolite decreases to 31.72 mJ/m2 and the percentage of polar component increases to 89.75%, thus leading to that the infrared emissivity of 3-MPTMS modified sepiolite increase to be higher than 0.8 and the dispersion of sepiolite has been improved. The excellent thermal insulation property of coating is prepared with 10% additive amount of 3-MPTMS modified sepiolite and the temperature difference between upper and lower box of modified sepiolite coatings is 10 degrees C which is higher than the untreated sepiolite.
    Journal of Nanoscience and Nanotechnology 05/2014; 14(5):3515-20. · 1.15 Impact Factor
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    ABSTRACT: A new Heusler alloy V2NiSb with Hg2CuTi-type structure has been obtained by means of first-principles calculations. The electric structure and magnetic properties of the alloy have been also investigated. The results show that the alloy has a total magnetic moment of 0.82μ B per unit cell on first-principles calculations. The magnetic moment of atom Ni is 0.13μ B ; the magnetic moments of V(1) atom and V(2) atom are −0.48μ B and 0.76μ B , respectively, indicating that the alloy is a antiferrimagnet.
    Journal of Superconductivity and Novel Magnetism 03/2014; 27(3). · 0.70 Impact Factor
  • Adam Perer, Fei Wang
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    ABSTRACT: Extracting insights from temporal event sequences is an important challenge. In particular, mining frequent patterns from event sequences is a desired capability for many domains. However, most techniques for mining frequent patterns are ineffective for real-world data that may be low-resolution, concurrent, or feature many types of events, or the algorithms may produce results too complex to interpret. To address these challenges, we propose Frequence, an intelligent user interface that integrates data mining and visualization in an interactive hierarchical information exploration system for finding frequent patterns from longitudinal event sequences. Frequence features a novel frequent sequence mining algorithm to handle multiple levels-of-detail, temporal context, concurrency, and outcome analysis. Frequence also features a visual interface designed to support insights, and support exploration of patterns of the level-of-detail relevant to users. Frequence's effectiveness is demonstrated with two use cases: medical research mining event sequences from clinical records to understand the progression of a disease, and social network research using frequent sequences from Foursquare to understand the mobility of people in an urban environment.
    Proceedings of the 19th international conference on Intelligent User Interfaces; 02/2014
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    ABSTRACT: On top of an enterprise social platform, we are building a smart social QA system that automatically routes questions to suitable employees who are willing, able, and ready to provide answers. Due to a lack of social QA history (training data) to start with, in this paper, we present an optimization-based approach that recommends both top-matched active (seed) and inactive (prospect) answerers for a given question. Our approach includes three parts. First, it uses a predictive model to find top-ranked seed answerers by their fitness, including their ability and willingness, to answer a question. Second, it uses distance metric learning to discover prospects most similar to the seeds identified in the first step. Third, it uses a constraint-based approach to balance the selection of both seeds and prospects identified in the first two steps. As a result, not only does our solution route questions to top-matched active users, but it also engages inactive users to grow the pool of answerers. Our real-world experiments that routed 114 questions to 684 people identified from 400,000+ employees included 641 prospects (93.7%) and achieved about 70% answering rate with 83% of answers received a lot/full confidence.
    Proceedings of the 19th international conference on Intelligent User Interfaces; 02/2014
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    ABSTRACT: Diffusion and cascades have been studied for many years in sociology, and different theoretical models have been developed. However, experimental validation has been always carried out in relatively small datasets. In recent years, with the availability of large-scale network and cascade data, research on cascading and diffusion phenomena has aroused considerable interests from various fields in computer science. One of the main goals is to discover different propagation patterns from historical cascade data. In this context, understanding the mechanisms underlying diffusion in both micro- and macro-scale levels and further develop predictive model of diffusion are fundamental problems of crucial importance.
    Proceedings of the 7th ACM international conference on Web search and data mining; 02/2014
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    ABSTRACT: Nowadays, the Heusler alloy is a hot material system explored for new functional materials in condensed matter physics and materials science. A lot of Heusler alloys usually have a cubic L21 structure with high chemical ordering. The L21 structure has two types: Cu2MnAl-type and Hg2CuTi-type. For given elements, different L21 structures can generate different properties. Based on the minimum energy theory, a method is proposed to determine which structure will be chosen from the two in the crystallization of an L21 structure.
    Journal of Superconductivity and Novel Magnetism 02/2014; 27(2). · 0.70 Impact Factor
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    ABSTRACT: Spintronics is attracting increasing attention due to the potential applications of spintronic devices in information storage, microprocessors, and a host of other technologies. Half-metal, as one of the most important spin injection source in spintronics, should be investigated deeply. Based on the above reason, this paper briefly summarizes the research progress of different kinds of half-metallic materials, and research orientations related to half-metallic materials are also proposed.
    Journal of Superconductivity and Novel Magnetism 02/2014; 27(2). · 0.70 Impact Factor
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    ABSTRACT: Care pathways (CPs) as a means of healthcare quality control are getting increasing attention due to widespread recognition in the healthcare industry of the need for well coordinated, evidence based and personalized care. To keep the promise, CPs require continuous refinement in order to stay up to date with regard to both clinical guidelines and data-driven insights from real world practices. There is therefore a strong demand for a unified platform that allows harmonization of evidence coming from multiple sources. In this paper we describe Care Pathway Workbench, a web-based platform that enables users to build and continuously improve Case Management Model and Notation based CPs by harmonizing evidences from guidelines and patient data. To illustrate the functionalities, we describe how a CHF (Congestive Heart Failure) Ambulatory Care Pathway can be developed using this workbench by first extracting key elements from widely accepted guidelines for CHF management, then incorporating evidence mined from clinical practice data, and finally transforming and exporting the resulting CP model to a care management product.
    Studies in health technology and informatics 01/2014; 205:23-27.
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    ABSTRACT: Previous work has shown that aeolian Red Clay first appears at around 8 Ma in the main Chinese Loess Plateau and at 25-22 Ma in the western Loess Plateau; however, records of aeolian deposition in the North Pacific suggest that aeolian accumulation occurred throughout the Cenozoic, and that changes in aeolian flux occurred in distinct stages. Tracing the Cenozoic aeolian history of the interior of the Asian continent may help us to understand the history of Asian aridification and its driving forces. In the Lanzhou area on the western margin of the Loess Plateau and the northeastern edge of the Tibetan Plateau, the Cenozoic stratigraphic sequence consists of fluvial-lacustrine sediments in the lower part, aeolian Red Clay with intercalated fluvial layers in the middle part, and predominantly aeolian loess in the upper part. We use high resolution palaeomagnetic measurements of this sequence to construct a time scale, and measurements of sediment rock magnetic properties, grain-size, color reflectance and sedimentary facies analysis to reconstruct the palaeoenvironment. The results show that prior to 33 Ma the area was dominantly a fluvial-lacustrine environment, and that subsequently an aridification trend commenced, as indicated by the appearance of aeolian sediment. This change coincided with, and is thus explained as the environmental response to global cooling. A significant increase in aeolian sediments occurred at ~ 26 Ma, suggesting that a large scale arid environment had formed in the Asian interior since the late Oligocene. Stepwise increases of aeolian sediment, and decreases in sediments of hydraulic origin, occurred at ~ 22.0, ~ 14, ~ 8 and 2.6 Ma and represent important stages in the aridification process. This long-term trend was interrupted by intervals dominated by fluvial sedimentation at 23.6-22.0 Ma and 17.1-14.1 Ma and which were probably associated with warming of the global climate and the tectonic uplift of the northeastern Tibetan Plateau. Tectonic events occurring in Lanzhou at ~ 9.0-8.0 Ma and ~ 3.5 Ma indicate strong uplift of the northeastern Tibetan Plateau.
    Global and Planetary Change 01/2014; · 3.16 Impact Factor
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    ABSTRACT: Glazes have great influence on most of the final properties of sanitary wares, such as color, glossy, and surface roughness. Generally, these properties have been changed by chemical composition and firing parameters. In addition, the selection of particle-size distribution of raw glaze can affect on the surface appearance and cleanability of glazed surface. In this paper, raw glazes were milled in ball mill for different time. Prepared glaze slurry was applied to green bodies, later dried and fired. The same glaze was also uniaxially pressed to form cylindrical sample; the specimen was placed on substrate surface and fired in hot stage microscope. The glaze evolution upon heating was recorded by CCD camera, the contact angle between molten glaze and substrate was measured to determine the wettability. The results showed that particle-size distributions have great influence on the melting behavior of glaze and the surface appearance of glazed ceramics.
    Journal of Thermal Analysis and Calorimetry 01/2014; 115(2). · 1.60 Impact Factor
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    ABSTRACT: The surface modification reactions on sepiolite have been carried out to prepare modified sepiolite nanofibers using γ-(2,3-epoxypropoxy)propytrimethoxysilane, and the dispersion stability of sepiolite nanofibers in water has been systematically studied. The results showed that the dispersion stability of modified sepiolite nanofibers was improved significantly. When the amount of γ-(2,3-epoxypropoxy)propytrimethoxysilane in sepiolite nanofibers is 1.63%, the stability of sepiolite nanofibers dispersion reaches the best. The reason was that the surface modification on sepiolite increased zeta potential and decreased surface free energy, which leads to the increase of repulsive energy between nanofibers and the degradation of attractive energy, respectively. The interaction between repulsive and attractive energy results in the increase of energy barrier which overcomes agglomeration and sedimentation of sepiolite nanofibers.
    Nanoscience and Nanotechnology Letters 01/2014; 6(4). · 1.44 Impact Factor
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    ABSTRACT: The modified sepiolite nanofibers were obtained by organic modification, using γ-(2,3-epoxypropoxy)propytrimethoxysilane as silane coupling agent. On the basis, rigid polyurethane foams composite materials containing modified sepiolite nanofibers and hollow glass microspheres were obtained, and the effect of modified sepiolite nanofibers and hollow glass microspheres on performance of rigid polyurethane foams composite materials were also studied. The microstructure, mechanical properties and thermal stability of the composite materials were measured by scanning electron microscope, Fourier transform infrared spectrum, universal tensile testing machine and differential thermal analyzer. The results indicated that sepiolite nanofibers and hollow glass microspheres dispersed in rigid polyurethane foams matrix homogeneously with strong physical and chemical interaction, and surface functional groups with special structure were formed. Consequently, modified sepiolite nanofibers and hollow glass microspheres have great influence on the mechanical properties and thermal stability of the rigid polyurethane foams composite materials. When the contents of sepiolite nanofibers and hollow glass microspheres were 15% and 10%, the tensile strength, breaking elongation rate and compressive strength of the composite materials were increased by 240%, 410% and 300%, respectively. Thermal weight loss central temperature of the composite materials was increased obviously, showing the better thermal stability of the composite materials after being reinforced by modified sepiolite nanofibers and hollow glass microspheres.
    Nanoscience and Nanotechnology Letters 01/2014; 6(6). · 1.44 Impact Factor
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    ABSTRACT: Two high-resolution δ13C records of ∼5.4 and ∼4.4 ka coral colonies Porites lutea from east coast of Hainan Island in the northern South China Sea (SCS) provide insights into the complex links between coral carbon isotopes and environment changes. The δ13C of the ∼5.4 ka coral offered a 40-year growth history with an average of −2.62‰ and amplitude of 2.96‰, the ∼4.4 ka coral's revealed a 55-year growth history with an average of −3.12‰ and amplitude of 4.21‰, which revealed higher coral δ13C and increased seasonality in the middle Holocene. Our analysis suggests that the higher coral δ13C was the combined result of higher radiation, salinity and nutrient level and lower atmosphere CO2 concentration, which might increase coral δ13C through strengthening photosynthesis of symbiont zooxanthella in the context of kinetic and metabolic fractionations. The increased seasonality was mostly produced by strengthened radiation. The decreasing standard deviation of the ∼5.4 ka coral annual δ13C revealed weakened interannual changes of atmospheric CO2, salinity, and nutrient. By contrast, the increasing deviation of the ∼4.4 ka coral δ13C suggests strengthened interannual changes of these variables. The ∼5.4 ka coral δ13C showed a long-term increasing trend at a rate of 0.33% increase y−1, which was attributed to natural decrease in atmospheric CO2, and increasing salinity and nutrient level. However, the ∼4.4 ka coral δ13C showed a long term decreasing trend at a rate of 0.25% decrease y−1, which was ascribed to unusual increase in atmospheric CO2, and decreasing salinity and nutrient level.
    Quaternary International 01/2014; · 1.96 Impact Factor
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    ABSTRACT: The retreat of the Tethys Sea and the uplift of the Tibetan Plateau play the critical roles in driving Asian climatic changes during the Cenozoic. In the Pamir–Tien Shan convergence zone, over 3000 m of Cenozoic successions, consisting of marine deposits in the lower, continental clay and fine sand in the middle, and molasse in the upper part, record the evolution of the Tethys Sea, the Asian aridification, and the deformation of the Pamir. In this work, the existing biostratigraphic subdivisions and new electronic spinning resonance dating results were used to assign ages to formations within the Ulugqat section. Sedimentary facies analysis and multi-proxy indices were used to reconstruct the paleo-environmental evolution. The results show: (1) the Pamir–Tien Shan convergence zone has undergone progressive environmental changes from shallow marine before ∼34 Ma to arid land at ∼23 Ma and finally to inter-mountain basin by ∼5.3 Ma; (2) the overall increase in mean size of grains, decrease in redness, in magnetic susceptibility, and in proportion of the ultrafine component of the sediments studied revealed a long-term strengthening in potential energy to transporting medium, cooling, and enhanced continental aridity, respectively; (3) the easternmost edge of the Tethys Sea prevailed in the western Tarim Basin from late Cretaceous to early Cenozoic, and finally retreated from this region around the Eocene–Oligocene transition, which in turn strengthened the Asian aridification; (4) accumulation of molasse with an upper age of ∼1 Ma suggests that the deformation front of the Pamir migrated to this area at or before that time.
    Journal of Asian Earth Sciences. 01/2014; 80:84–100.
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    ABSTRACT: The desertification history of inland Asia provides most direct evidence for Asian drying history, but the formation ages of the most Asian deserts are not clear due to the lack of outcrops. The Tengger Desert, one of the main proximal deserts of the Chinese Loess Plateau (CLP), is of special paleoclimatic significances for its dust emission and environmental affection. Here, we report lithofacies, paleomagnetic ages and paleoenvironmental proxy indexes of the first drill core (WEDP01) from the central Tengger Desert. Paleomagnetism measurements reveal that the core spans from ∼3.55 Ma to present, consistent with the electron spin resonance (ESR) dating results. The strata of the central desert consist of alluvial–fluvial deposits, lacustrine–fluvial deposits mixed with dust, and eolian sand from bottom to top. Sedimentary analysis reveals that continuous eolian sand started by ∼0.9 Ma, marking the initial formation of the Tengger Desert; and the domination of eolian sand in the strata with similar characters of the modern desert appeared by ∼0.68 Ma, indicating expansion of the Tengger Desert. The proximal deserts formation and simultaneous increase of dust accumulation in the CLP and the North Pacific Ocean in mid-Pleistocene demonstrate the role of proximal deserts for the dust loading of Northern China and even Northern Hemisphere. Our analysis suggests the uplift of Tibetan Plateau in the mid-Pleistocene probably played the main role for this drying event and desert formation, while global cooling may strength the arid environment of the proximal deserts.
    Quaternary Science Reviews 01/2014; 85:85–98. · 4.57 Impact Factor
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    ABSTRACT: In this article, a new Heusler alloy V2CuAl with Hg2CuTi-type structure has been obtained by first-principles calculations. The electric structure and magnetic performance of the alloy have also been investigated. The results show that the alloy has a total magnetic moment of 0.87μB per unit cell obtained by first-principles calculations. In addition, the conducting character and metal property are presented by the majority and minority spin band structures calculations. Furthermore, the magnetic moments of V(1) atom and V(2) atom are 0.36μB and 0.38μB, respectively, indicating that the alloy is a ferromagnet.
    Journal of Alloys and Compounds 01/2014; 603:180–182. · 2.73 Impact Factor
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    ABSTRACT: In this article, the supercells of pure anatase titanium dioxide, nitrogen and/or chromium doping anatase titanium dioxide were computed using first-principles with the plane-wave ultrasoft pseudopotentials method, and the electronic structure and optical properties of different ions doping models were also studied. The results indicated that the band gap and charge carriers recombination rate of nitrogen and chromium codoped system are all decreased effectively, and the separation of electron–hole pairs becomes more favorable due to impurity energy levels formation in the band gap of anatase titanium dioxide, which could play an important role in enhancing the catalytic activity and visible light absorption of anatase titanium dioxide. Furthermore, the optical absorption curves of nitrogen and chromium codoped anatase titanium dioxide indicate the highest photoresponse for visible-light, which is consistent with the previous experimental results. The above results would be quite helpful for research guiding and further developing of titanium dioxide photocatalyst.
    Journal of Alloys and Compounds 01/2014; 611:125–129. · 2.73 Impact Factor
  • David Gotz, Fei Wang, Adam Perer
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    ABSTRACT: Patients’ medical conditions often evolve in complex and seemingly unpredictable ways. Even within a relatively narrow and well-defined episode of care, variations between patients in both their progression and eventual outcome can be dramatic. Understanding the patterns of events observed within a population that most correlate with differences in outcome is therefore an important task in many types of studies using retrospective electronic health data. In this paper, we present a method for interactive pattern mining and analysis that supports ad hoc visual exploration of patterns mined from retrospective clinical patient data. Our approach combines (1) visual query capabilities to interactively specify episode definitions, (2) pattern mining techniques to help discover important intermediate events within an episode, and (3) interactive visualization techniques that help uncover event patterns that most impact outcome and how those associations change over time. In addition to presenting our methodology, we describe a prototype implementation and present use cases highlighting the types of insights or hypotheses that our approach can help uncover.
    Journal of Biomedical Informatics 01/2014; · 2.13 Impact Factor

Publication Stats

825 Citations
86.55 Total Impact Points

Institutions

  • 2014
    • Huaiyin Institute of Technology
      Ch’ing-chiang, Jiangsu Sheng, China
  • 2011–2014
    • IBM
      Armonk, New York, United States
    • Purdue University
      • Department of Computer Science
      West Lafayette, IN, United States
  • 2010–2014
    • Hebei University of Technology
      T’ien-ching-shih, Tianjin Shi, China
    • Cornell University
      • Department of Statistical Science
      Ithaca, New York, United States
  • 2009–2011
    • Florida International University
      • School of Computing and Information Sciences
      Miami, Florida, United States
  • 2005–2010
    • Tsinghua University
      • Department of Automation
      Beijing, Beijing Shi, China