2,219 research outputs found

    Characterization of soil heavy metal pools in paddy fields in Taiwan: chemical extraction and solid-solution partitioning

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    Ongoing industrialization has resulted in an accumulation of metals like Cd, Cu, Cr, Ni, Zn, and Pb in paddy fields across Southeast Asia. Risks of metals in soils depend on soil properties and the availability of metals in soil. At present, however, limited information is available on how to measure or predict the directly available fraction of metals in paddy soils. Here, the distribution of Cd, Cu, Cr, Ni, Zn, and Pb in 19 paddy fields among the total, reactive, and directly available pools was measured using recently developed concepts for aerated soils. Solid-solution partitioning models have been derived to predict the directly available metal pool. Such models are proven to be useful for risk assessment and to derive soil quality standards for aerated soils. Soil samples (0-25 cm) were taken from 19 paddy fields from five different communities in Taiwan in 2005 and 2006. Each field was subdivided into 60 to 108 plots resulting in a database of approximately 3,200 individual soil samples. Total (Aqua Regia (AR)), reactive (0.43 M HNO3, 0.1 M HCl, and 0.05 M EDTA), and directly available metal pools (0.01 M CaCl2) were determined. Solid-solution partitioning models were derived by multiple linear regressions using an extended Freundlich equation using the reactive metal pool, pH, and the cation exchange capacity (CEC). The influence of Zn on metal partitioning and differences between both sampling events (May/November) were evaluated. Total metals contents range from background levels to levels in excess of current soil quality standards for arable land. Between 3% (Cr) and 30% (Cd) of all samples exceed present soil quality standards based on extraction with AR. Total metal levels decreased with an increasing distance from the irrigation water inlet. The reactive metal pool relative to the total metal content is increased in the order C

    Microcanonical Jet-fragmentation in proton-proton collisions at LHC Energy

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    In this paper, we show that the distribution of the longitudinal momentum fraction of charged hadrons dN/dzdN/dz inside jets stemming from proton-proton collisions at s\sqrt{s} = 7 TeV center of mass energy can be described by a statistical jet-fragmentation model. This model combines microcanonical statistics and super-statistics induced by multiplicity fluctuations. The resulting scale dependence of the parameters of the model turns out to be similar to what was observed in electron-positron annihilations in Urmossy, Barnaf\"oldi, and Bir\'o.Comment: 7 pages, 8 figure

    Cultural differences in intimacy: The influence of gender-role ideology and individualism-collectivism

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    Two studies examined emotional intimacy in European Canadian and Chinese Canadian dating relationships. Cultural differences in gender-role ideology and individualism–collectivism were hypothesized to differentially contribute to selfdisclosure and responsiveness, and in turn, intimacy. Study 1 revealed that Chinese Canadians’ lower intimacy relative to European Canadians was mediated by their greater gender-role traditionalism but not by their individualism or collectivism. Study 2 further linked greater gender-role traditionalism to lower self-disclosure, and in turn, lower intimacy. Results also revealed that Chinese Canadians’ lower intimacy mediated their lower relationship satisfaction and higher rate of relationship termination in Study 1, but that Chinese Canadians were not any more likely to terminate their relationships in Study 2

    The multifrequency Siberian Radioheliograph

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    The 10-antenna prototype of the multifrequency Siberian radioheliograph is described. The prototype consists of four parts: antennas with broadband front-ends, analog back-ends, digital receivers and a correlator. The prototype antennas are mounted on the outermost stations of the Siberian Solar Radio Telescope (SSRT) array. A signal from each antenna is transmitted to a workroom by an analog fiber optical link, laid in an underground tunnel. After mixing, all signals are digitized and processed by digital receivers before the data are transmitted to the correlator. The digital receivers and the correlator are accessible by the LAN. The frequency range of the prototype is from 4 to 8 GHz. Currently the frequency switching observing mode is used. The prototype data include both circular polarizations at a number of frequencies given by a list. This prototype is the first stage of the multifrequency Siberian radioheliograph development. It is assumed that the radioheliograph will consist of 96 antennas and will occupy stations of the West-East-South subarray of the SSRT. The radioheliograph will be fully constructed in autumn of 2012. We plan to reach the brightness temperature sensitivity about 100 K for the snapshot image, a spatial resolution up to 13 arcseconds at 8 GHz and polarization measurement accuracy about a few percent. First results with the 10-antenna prototype are presented of observations of solar microwave bursts. The prototype abilities to estimate source size and locations at different frequencies are discussed

    Structural Characterization of Rapid Thermal Oxidized Si\u3csub\u3e1−x−y\u3c/sub\u3eGe\u3csub\u3ex\u3c/sub\u3eC\u3csub\u3ey\u3c/sub\u3e Alloy Films Grown by Rapid Thermal Chemical Vapor Deposition

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    The structural properties of as-grown and rapid thermal oxidized Si1−x−yGexCy epitaxial layers have been examined using a combination of infrared, x-ray photoelectron, x-ray diffraction, secondary ion mass spectroscopy, and Raman spectroscopy techniques. Carbon incorporation into the Si1−x−yGexCy system can lead to compressive or tensile strain in the film. The structural properties of the oxidized Si1−x−yGexCy film depend on the type of strain (i.e., carbon concentration) of the as-prepared film. For compressive or fully compensated films, the oxidation process drastically reduces the carbon content so that the oxidized films closely resemble to Si1−xGex films. For tensile films, two broad regions, one with carbon content higher and the other lower than that required for full strain compensation, coexist in the oxidized films

    The antiferromagnetic phi4 Model, II. The one-loop renormalization

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    It is shown that the four dimensional antiferromagnetic lattice phi4 model has the usual non-asymptotically free scaling law in the UV regime around the chiral symmetrical critical point. The theory describes a scalar and a pseudoscalar particle. A continuum effective theory is derived for low energies. A possibility of constructing a model with a single chiral boson is mentioned.Comment: To appear in Phys. Rev.

    Isoscalar Giant Dipole Resonance and Nuclear Matter Incompressibility Coefficient

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    We present results of microscopic calculations of the strength function, S(E), and alpha-particle excitation cross sections sigma(E) for the isoscalar giant dipole resonance (ISGDR). An accurate and a general method to eliminate the contributions of spurious state mixing is presented and used in the calculations. Our results provide a resolution to the long standing problem that the nuclear matter incompressibility coefficient, K, deduced from sigma(E) data for the ISGDR is significantly smaller than that deduced from data for the isoscalar giant monopole resonance (ISGMR).Comment: 4 pages using revtex 3.0, 3 postscript figures created by Mathematica 4.

    High frequency CMOS amplifier with improved linearity

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    In this paper, a novel amplifier linearisation technique based on the negative impedance compensation is presented. As demonstrated by using Volterra model, the proposed technique is suitable for linearising amplifiers with low open-loop gain, which is appropriate for RF/microwave applications. A single-chip CMOS amplifier has been designed using the proposed method, and the simulation results show that high gain accuracy (improved by 38%) and high linearity (IMD3 improved by 14 dB, OIP3 improved by 11 dB and adjacent channel power ratio (ACPR) improved by 44% for CDMA signal) can be achieved

    A novel electrode with multifunction and regeneration for highly efficient and stable symmetrical solid oxide cell

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    Authors acknowledge financial support from National Key Research & Development Project (2016YFE0126900), National Natural Science Foundation of China (51672095, U1910209), and China Scholarship Council (201806160178). The work is also partially supported by State Key Laboratory of Materials Processing and Die & Mould Technology, Huazhong University of Science and Technology (P2019-004).Symmetrical solid oxide cells (SSOCs) have been extensively recognized due to their simple cell configuration, low cost and reliability. High performance electrode is the key determinant of SSOCs. Herein, a multifunctional perovskite oxide La0.6Ca0.4Fe0.8Ni0.2O3-ÎŽ (LCaFN) is investigated as electrode for SSOCs. The results confirm that LCaFN shows excellent oxygen reduction reaction (ORR), oxygen evolution reaction (OER), carbon dioxide reduction reaction (CO2-RR) and hydrogen oxidation reaction (HOR) catalytic activity. In SOFC mode, the SSOCs with LCaFN achieve good electrochemical performance with maximum power density of 300 mW cm−2 at 800 °C. For pure CO2 electrolysis in SOEC mode, polarization resistance of 0.055 Ω cm2 and current density of 1.5 A cm−2 are achieved at 2.0 V at 800 °C. Besides, the cell shows excellent stability both in SOFC mode and SOEC mode. Most importantly, SSOCs with symmetrical LCaFN electrodes show robust and regenerative performance under anodic or cathodic process during the switching gas, showing the great reliability of the SSOCs. The results show that this novel electrode offers a promising strategy for operation of SSOCs.PostprintPeer reviewe

    Bio-pulsating architecture for object-based processing in next generation vision systems

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