1,437 research outputs found
The Change of Philosophical Discourse in the Context of Economics
No full textWithout a doubt Karl Marx’ philosophical work had a huge impact on “western” concepts of society and economics that still reverberates in the philosophical discourse. In the analysis of this ongoing discourse however the work of Chinese scholars is underrepresented. This book is a translation of the reference work «Back to Marx» first published in 1999 in the PRC. The book is a serious inquiry into the interrelationships between Marx‘s political and economic philosophy, based on careful and systematic reading of a wide range of textual sources, including—in particular—the newly published second edition of the Complete Works of Marx and Engels (MEGA2), which collects notes, drafts, manuscripts, and excerpts previously unavailable to the scholarly community. The author Zhang Yibing teaches philosophy at the University of Nanjing and is one of the foremost scholars of Marxism in the PRC, a Marxist analyst of contemporary philosophical issues. At the same time he is the Vice Chancellor of the University
Interface plasmon excitations of superlattices with defects
No full textInterface plasmon excitations of superlattices with defects are investigated by the propagation matrix method. A dispersion relation is obtained and is shown to be of sufficient generality. The dispersion curves of the local modes are shown to be dependent upon the thickness and the dielectric constant of the defect layer. The obtained formula generalizes some earlier results obtained by other authors. Several special cases, including the limiting cases of quantum-well layered structures, are discussed and a new mode similar to the Giuliani and Quinn type mode is deduced
Relationships between soil properties and toxicity of copper and nickel to bok choy and tomato in Chinese soils
No full textAbstract not availableBo Li, Hongtao Zhang, Yibing Ma, and Mike J. McLaughli
Anisotropy of surface plasmons in metals
No full textIn this paper we propose a phenomenological model to explain the anisotropy in the dispersion of surface plasmons, which we suggest to be related also to the different effective mass of the electrons involved in the excitation. The model is applied to silver surfaces where a large set of experimental data exists, obtaining a good qualitative agreement with experiment. The damping of the surface plasmons is also discussed. Again in agreement with the experimental results, a linear dependence on temperature and momentum transfer is found for the linewidth. The anisotropy of the latter is then determined by the anisotropy of the effective mass and of the relaxation time of the electrons in the surface region, tau(surf), and is small only if tau(surf) approximate to tau(bulk)
The Change of Philosophical Discourse in the Context of Economics
No full textHardcover, 17x24Without a doubt Karl Marx’ philosophical work had a huge impact on “western” concepts of society and economics that still reverberates in the philosophical discourse. In the analysis of this ongoing discourse however the work of Chinese scholars is underrepresented. This book is a translation of the reference work «Back to Marx» first published in 1999 in the PRC. The book is a serious inquiry into the interrelationships between Marx‘s political and economic philosophy, based on careful and systematic reading of a wide range of textual sources, including—in particular—the newly published second edition of the Complete Works of Marx and Engels (MEGA2), which collects notes, drafts, manuscripts, and excerpts previously unavailable to the scholarly community. The author Zhang Yibing teaches philosophy at the University of Nanjing and is one of the foremost scholars of Marxism in the PRC, a Marxist analyst of contemporary philosophical issues. At the same time he is the Vice Chancellor of the University
Photosensitized and photocatalyzed degradation of azo dye using Lnⁿ⁺- TiO₂sol in aqueous solution under visible light irradiation
No full textAuthor name used in this publication: Yibing XieAuthor name used in this publication: Xiangzhong Li2004-2005 > Academic research: refereed > Publication in refereed journalAccepted ManuscriptPublishedGreen (AAM
Effects of channel wall wettability on gas–liquid dynamics mass transfer under Taylor flow in a serpentine microchannel
No full textThe wall wettability of microchannels plays an important role in the gas–liquid mass transfer dynamics under Taylor flow. In this study, we regulated the contact angle of the wall surface through surface chemical grafting polymerization under controlled experimental conditions. The dynamic changes of CO2 bubbles flowing along the microchannel were captured by a high-speed video camera mounted on a stereo microscope, whilst a unit cell model was employed to theoretically investigate the gas–liquid mass transfer dynamics. We quantitatively characterized the effects of wall wettability, specifically the contact angle, on the formation mechanism of gas bubbles and mass transfer process experimentally. The results revealed that the gas bubble velocity, the overall volumetric liquid phase mass transfer coefficients (kLa), and the specific interfacial area (a) all increased with the increase of the contact angle. Conversely, gas bubble length and leakage flow decreased. Furthermore, we proposed a new modified model to predict the gas–liquid two-phase mass transfer performance, based on van Baten's and Yao's models. Our proposed model was observed to agree reasonably well with experimental observations
Surface plasmon dispersion and damping on Ag(111)
No full textSurface plasmon dispersion and damping on Ag(111) were studied by angle-resolved electron-energy-loss spectroscopy. We find a positive dispersion, which can be described only assuming nonzero values for both linear and quadratic terms. The best-fit values are close to those of Ag(110) (1(1) over bar0$), confirming the similarity in the behavior of close-packed surfaces and close-packed directions on open surfaces. Surface plasmon damping depends weakly on momentum transfer, q(parallel to), for small q(parallel to), again in analogy to the case of Ag(110) (1 (1) over bar 0). This result demonstrates the existence of a link between surface plasmon dispersion and the q(parallel to) dependence of surface plasmon damping. Beyond a critical q(parallel to) the linewidth of the losses increases strongly with q(parallel to), as was the case also for Ag(001). The effect is ascribed to the opening of a decay channel involving the image potential state
Influences of soil properties and leaching on nickel toxicity to barley root elongation
No full textThe influence of soil properties on Ni toxicity to barley root elongation was investigated using 17 Chinese soils treated with soluble Ni salts, with and without leaching. The effective concentration of added Ni causing 50% inhibition (EC50) in barley root elongation ranged from 48 to 2519 mg/kg in unleached soils and 46 to >2381 mg/kg in leached soils. Leaching decreased Ni phytotoxicity significantly for approximately 90% of soils, and the effect was most pronounced for soils with pH ≥8.2. Soil pH was the most important factor controlling Ni toxicity in soils, explaining approximately 68% of the variance in unleached and leached EC50 values. Regression models between toxicity thresholds and soil pH, soil organic carbon content, or effective cation exchange capacity were developed. The models showed good agreement with those developed previously for European soils (r(2)=0.87). These quantitative relationships between Ni toxicity and soil properties are helpful to develop soil-specific guidance on Ni toxicity thresholds for China.Bo Li, Hongtao Zhang, Yibing Ma, Mike J. McLaughli
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3D Oxygenation Imaging of Bone Marrow Using X-ray Luminescence micro-CT
No full textImaging hypoxia heterogeneity or low oxygenation distribution at high spatial resolution in deep tissues, such as bone marrow, is essential for understanding its role in stem cell proliferation and differentiation. Currently, although many imaging techniques can visualize oxygen distribution, they are limited either by high spatial resolution or by their ability to image oxygenation distribution in deep tissues. X-ray Luminescence Computed Tomography (XLCT) is a novel functional imaging modality that overcomes these limitations by achieving high resolution at the micrometer scale in tissues as deep as several centimeters. This is feasible because XLCT combines the advantages of X-ray imaging's high spatial resolution and optical imaging's high sensitivity. Furthermore, XLCT imaging has been introduced as a powerful new hybrid molecular imaging modality, capable of high-resolution imaging of deeply embedded x-ray excitable contrast agents in three dimensions (3D). This dissertation focuses on improving XLCT imaging and its applications in measuring oxygenation concentrations in deep tissues.Initially, the XLCT imaging system was enhanced by introducing a new reconstruction algorithm, the weighted sinogram-based filtered back projection (wsFBP). This novel reconstruction algorithm has improved the conventional FBP by introducing a weighted sinograms to compensate for the different optical photon attenuations across different paths through the object being imaged. To evaluate this innovative algorithm, we have fabricated phantoms with different phosphor targets which consisted of capillary tubes filled with Gd2O2S: Eu3+ agar solution, a compound that scintillates under x-ray exposure. We have designed five target configurations: targets placed near the center of the phantom, offset from the center, targets filled with four different concentrations, a capillary glass tube without contrast agent solution, and only contrast solution without the capillary glass tube. The aim was to assess the sensitivity and quantitative capabilities of the XLCT imaging system. The results showed that the proposed wsFBP algorithm could significantly reduce metal artifacts around the reconstructed targets compared to the conventional FBP method, providing clearer and more uniformly intense target imaging. The system also managed to image contrast agent concentrations as low as 0.01 mg/mL. The system's quantification ability is semi-quantitative; it quantifies contrast agent concentrations accurately between 10 and 1 mg/mL, but at lower concentrations from 0.1 to 0.01 mg/mL, the accuracy drops due to the very low concentration and the capillary tube's weak optical emission when excited by x-rays. Nonetheless, the reconstruction of only contrast agent targets at a very low concentration, 0.01 mg/mL, was successful. With this new reconstruction algorithm, we can perform XLCT imaging both quantitatively and straightforwardly.We investigated the factors influencing photon collection efficiency in XLCT, focusing on the orientation of the fiber bundle or detector and the distance from the imaged object surface. In this study, we have built a novel optical detector holder, which allows the detector to rotate vertically from 0 degrees to 45 degrees. We found that the orientation of the fiber bundle significantly affects photon collection, with collection efficiency significantly decreasing as the detector rotates from 0 to 45 degrees. However, we still managed to reconstruct clear target imaging at 45 degrees. Regarding the detector distance, increasing the distance between the detector and the object surface beyond 10 mm impacts photon collection, although the reasons for the observed slight increase in photon counts as the distance extends from 0 mm to 10 mm remain unclear, possibly due to changes in pre-amplifier gain. When the detector distance exceeds 30 mm, the optical photon detection efficiency decreases by about 33%. This comprehensive analysis supports future improvements in XLCT imaging detector configurations for its future applications.Lastly, the XICT imaging system was improved to include the capability of measurements at multiple wavelengths, through which it is possible to sense the oxygenation concentration by measuring the emission optical photons at two different wavelengths. Two oxygenation biosensors, YOS_PtTFPP and LSO_PtTFPP, were developed and used for oxygenation imaging by measuring emitted optical photons at two different wavelengths. These sensors were synthesized using an oxygen-sensitive dye (PtTFPP) and scintillator particles (Y2O2: Tb or Lu2SiO: Ce). This film was referred to as YOS_PtTFPP or LSO_PtTFPP. It was found that the ratio of the emission intensities at the two wavelengths (600 nm and 650 nm) indicates the oxygenation concentrations. Both phantom and ex vivo experiments were performed to verify this approach. We found that the ratio of measurements at two wavelengths was changed 2 times when the oxygenation was changed from 21% to 0% in the ex vivo study. Our results demonstrated that XLCT with these oxygenation biosensors is capable of achieving 3D oxygenation concentration images at high spatial resolution—up to 150 µm for targets at depths of up to 1.2 cm—representing the first application of XLCT for visualizing oxygen concentration changes in deep tissues
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