Showing papers by "Tongji University published in 2003"
TL;DR: In this article, a comprehensive review is presented on the researches and developments related to electrospun polymer nanofibers including processing, structure and property characterization, applications, and modeling and simulations.
6,987 citations
TL;DR: Functional analysis of the S140G mutant revealed a gain-of-function effect on the KCNQ1/KCNE1 and theKCNQ 1/ KCNE2 currents, which contrasts with the dominant negative or loss-of -function effects of the KCnQ1 mutations previously identified in patients with long QT syndrome.
Abstract: Atrial fibrillation (AF) is a common cardiac arrhythmia whose molecular etiology is poorly understood. We studied a family with hereditary persistent AF and identified the causative mutation (S140G) in the KCNQ1 (KvLQT1) gene on chromosome 11p15.5. The KCNQ1 gene encodes the pore-forming alpha subunit of the cardiac I(Ks) channel (KCNQ1/KCNE1), the KCNQ1/KCNE2 and the KCNQ1/KCNE3 potassium channels. Functional analysis of the S140G mutant revealed a gain-of-function effect on the KCNQ1/KCNE1 and the KCNQ1/KCNE2 currents, which contrasts with the dominant negative or loss-of-function effects of the KCNQ1 mutations previously identified in patients with long QT syndrome. Thus, the S140G mutation is likely to initiate and maintain AF by reducing action potential duration and effective refractory period in atrial myocytes.
916 citations
TL;DR: In this article, an analytical model based on a molecular mechanics approach is presented to relate the elastic properties of a single-walled carbon nanotube to its atomic structure and derive closed-form expressions for elastic modulus and Poisson's ratio as a function of the diameter.
Abstract: An analytical model based on a molecular mechanics approach is presented to relate the elastic properties of a single-walled carbon nanotube to its atomic structure. We derive closed-form expressions for elastic modulus and Poisson's ratio as a function of the nanotube diameter. Properties at different length scales are directly connected via these expressions. The analytically calculated elastic properties for achiral nanotubes using force constants obtained from experimental data of graphite are compared to those based on tight binding numerical calculations. This study represents a preliminary effort to develop analytical methods of molecular mechanics for applications in nanostructure modeling.
561 citations
TL;DR: In this paper, three types of hybrid composites were constructed using fiber combinations of polypropylene (PP) and carbon, carbon and steel, and steel and PP fibers at the same volume fraction (0.5%) in terms of compressive, splitting tensile, and flexural properties.
460 citations
TL;DR: In this article, weekly PM 2.5 samples were collected in Shanghai, China at two sites, Tongji University and Hainan Road, and the ambient mass concentration and chemical composition of the PM2.5 were determined.
441 citations
TL;DR: The Yellow Sea has been extensively studied for the understanding of dispersal patterns and limits of sediments from neighboring countries including China and Korea as mentioned in this paper, and various geochemical indicators from the literature for the provenance discrimination in the Yellow Sea are reviewed here in depth and corresponding discussions are described separately.
328 citations
TL;DR: In this paper, it was shown that a one-dimensional photonic crystal containing a negative-index material has an omnidirectional gap, owing to the mechanism of zero (volume) averaged refractive index.
Abstract: We show theoretically that a one-dimensional photonic crystal containing a negative-index material has an omnidirectional gap, owing to the mechanism of zero (volume) averaged refractive index. In contrast to the Bragg gap, the edge of such a zero-n gap is insensitive to incident angle and polarization. When an impurity is introduced, a defect mode appears inside the zero-n gap with a very weak dependence on incident angle and invariant with scaling.
297 citations
TL;DR: In this paper, an exact three-dimensional analysis for a functionally gradient piezoelectric material rectangular plate that is simply supported and grounded along its four edges is presented, assuming that the mechanical and electric properties of the material have the same exponent-law dependence on the thickness coordinate.
240 citations
TL;DR: In this article, the evolution of the East Asian monsoon over the past 2.2 Myr was investigated using the mineral assemblages at ODP Site 1146 in the northern South China Sea.
224 citations
TL;DR: In this article, the adsorption of high surface area (HSA)-activated carbons from aqueous solutions has been investigated, and both micropores and mesopores have important contribution.
192 citations
TL;DR: Based on a new comparison theorem, some less conservative conditions for asymptotic stability of impulsive control systems with impulses at fixed times are derived and the results are used to designImpulsive control for a class of nonlinear systems.
Abstract: This note studies the stability of impulsive control systems. A new comparison theorem for asymptotic stability of impulsive differential system is presented. Based on the new result, we derive some less conservative conditions for asymptotic stability of impulsive control systems with impulses at fixed times and the results are used to design impulsive control for a class of nonlinear systems. The class of nonlinear systems considered is also enlarged.
TL;DR: In this article, a high-resolution pollen record was obtained from ODP Site 1144 (water depth 2037 m), northern South China Sea for the last 103 million years according to micropaleontological and isotopic stratigraphy The pollen assemblages are characterized by high proportions of Pinus and herb pollen, and by their frequent alternations.
TL;DR: In this paper, the authors present apatite and zircon (U-Th)/He (AHe and ZHe, respectively) ages from the Dabie Shan that constrain the patterns and history of exhumation over the last 115 myr.
Abstract: The Dabie Shan of eastern China is a 200 kilometers wide mountain range with nearly 2 kilometers of relief and is an archetype of deep ultrahigh-pressure metamorphic rock exhumation. Despite its regional and petrologic importance, little is known about the low-temperature and post-orogenic evolution of the Dabie Shan. Here we present apatite and zircon (U-Th)/He (AHe and ZHe, respectively) and apatite fission-track (AFT) cooling ages from the Dabie Shan that constrain the patterns and history of exhumation over the last 115 myr. On the scale of the whole orogen, ZHe and AHe ages are inversely correlated with mean elevation and are systematically younger in the core of the range. These cooling ages were converted to exhumation rates assuming steady-state erosion and accounting for topographic effects. These results indicate that, since the Eocene, flanks of the range have eroded at rates as low as 0.02 km/myr, while the range core has eroded at about 0.06 km/myr. Even in the core of the range, these recent exhumation rates are at least 10 to 20 times slower than those estimated for the initial stages of exhumation in the Triassic-Jurassic. In a 1.4 kilometer vertical transect in the core of the range, all ages are positively correlated with elevation, with ZHe ages increasing from 76 to 112 Ma, AFT from 44 to 70 Ma, and AHe from 24 to 43 Ma. We present a simple model for topographic correction of thermochronometric ages in vertical transects, using the admittance ratio (ratio of isotherm relief to topographic relief). Applied to the AHe age-elevation relationship, this yields Tertiary exhumation rates of 0.05 to 0.07 km/myr in the core of the Dabie Shan, in good agreement with regional exhumation rate patterns. Finally, age-elevation relationships for all three chronometers in the vertical transect are consistent with a constant exhumation rate of 0.06 0.01 km/myr since the Creta- ceous, with a possible modest increase in exhumation rates (as high as 0.2 km/myr) between 80 to 40 Ma. These data show no evidence for significant variations in exhumation rates over the last 115 myr, as might be expected for decay of old topography or tectonic reactivation of old structures.
TL;DR: In this paper, a van der Pol-Duffing oscillator with excitation was used as a variable parameter to investigate its effect on the dynamics of the system such as the stability and bifurcation of an equilibrium point, phase locked (periodic) and phase shifting solution, period-doubling, quasi-periodic motion and chaos.
TL;DR: A high-resolution pollen record from 2 boreholes from the Changjiang (Yangtze River) delta shows a series of well-defined changes in vegetation and climate over the last 13,000 yr as discussed by the authors.
TL;DR: The GC/MS analysis demonstrated that some refractory compounds were decomposed at the acidogenic stage and resulted in the production of some intermediates, which were more readily degraded in the subsequent aerobic stage and hence, the A(1)-A(2)-O system had better effluent quality than the A-O system in terms of effluent composition.
TL;DR: A 30 m.y. stable isotopic record of marine-deposited black carbon from regional ter- restrial biomass burning from the northern South China Sea reveals photosynthetic path- way evolution for terrestrial ecosystems in the late Cenozoic.
Abstract: A 30 m.y. stable isotopic record of marine-deposited black carbon from regional ter- restrial biomass burning from the northern South China Sea reveals photosynthetic path- way evolution for terrestrial ecosystems in the late Cenozoic. This record indicates that C3 plants negatively adjusted their isotopic discrimination and C 4 plants appeared grad- ually as a component of land vegetation in East Asia since the early Miocene, a long time before sudden C4 expansion occurred during the late Miocene to the Pliocene. The changes in terrestrial ecosystems with time can be reasonably related to the evolution of East Asian monsoons, which are thought to have been induced by several intricate mechanisms during the late Cenozoic and could contribute significantly to the post-Miocene marine carbonate isotope decline.
TL;DR: In this article, geochemical and Nd isotopic changes in sediment samples at ODP Site 1148 in the South China Sea were investigated. But the authors focused on the change in provenance from southwest to north was largely caused by ridge jumping during seafloor spreading.
TL;DR: It is shown that the squared smoothing function is strongly semismooth and a new proof is provided, based on a penalized natural complementarity function, for the solution set of the second-order-cone complementarity problem being bounded.
Abstract: Two results on the second-order-cone complementarity problem are presented. We show that the squared smoothing function is strongly semismooth. Under monotonicity and strict feasibility we provide a new proof, based on a penalized natural complementarity function, for the solution set of the second-order-cone complementarity problem being bounded. Numerical results of squared smoothing Newton algorithms are reported.
TL;DR: In this paper, the authors investigated the thermal entanglement in the two-qubit Heisenberg XY model with a non-uniform magnetic field and found that the critical temperature T{sub C} may be enhanced under a non uniform magnetic field.
Abstract: We investigate the thermal entanglement in the two-qubit Heisenberg XY model with a nonuniform magnetic field. Concurrence, the measurement of entanglement, is calculated. The behavior of concurrence is present at three different cases. Contrary to the uniform magnetic field case, we find that the entanglement and the critical temperature T{sub C} may be enhanced under a nonuniform magnetic field.
TL;DR: In this paper, the thermal conductivity, electrical conductivity and Seebeck coefficient of hot-pressed Al 2 O 3 added ZnO ceramic samples were measured in dependence of temperature up to 600°C.
Abstract: Al 2 O 3 added ZnO powders were prepared via sol–gel processing, using zinc acetate, ammonia and Al 2 O 3 powders as starting materials. Scanning electron microscopy (SEM) observations indicated that the Al 2 O 3 added ZnO powders consisted of very fine particles (0.1–2 μm). The thermal conductivity, electrical conductivity and Seebeck coefficient of hot-pressed Al 2 O 3 added ZnO ceramic samples were measured in dependence of temperature up to 600 °C. The influence of Al 2 O 3 addition on the thermoelectric (TE) properties of ZnO ceramics is discussed.
TL;DR: The present study indicates that the braiding composite plate with 2.6mm thickness can be suitable for forearm treatment whereas the braided composite plate of 3.2mm thickness is applicable to femur or tibia fixation.
TL;DR: In this paper, a procedure for detecting structural damage based on a micro-genetic algorithm using incomplete and noisy modal test data is described, which is applied to a single-span simply supported beam and a three-span continuous beam with multiple damage locations.
TL;DR: A recent study at Ocean Drilling Program Site 1143 from the South China Sea showed that the mid-Brunhes event ca. 430 ka coincided with the largest-amplitude change in d 18 O in the global ocean over the past 6 m.y.y as mentioned in this paper.
Abstract: The beginning of the mid-Brunhes event ca. 430 ka coincided with the largest-amplitude change in d 18 O in the global ocean over the past 6 m.y. This large d 18 O change recorded a major ice-sheet expansion that cannot be explained by small changes in orbital forcing. Our recent studies at Ocean Drilling Program Site 1143 from the South China Sea show that this large d 18 O change was preceded by a significant negative d 13 C shift. A global survey of long deep-sea records has revealed periodic d 13 Cmax episodes (i.e., maximum positive values of d 13 C), and both major ice-sheet expansion events in the Pleistocene (the mid-Brunhes event and the middle Pleistocene revolution) were preceded by d 13 Cmax ep- isodes followed by negative d 13 C shifts. This new finding suggests that disturbance in carbon reservoirs leads to major growth of ice-sheet size and challenges the prevalent concept of Arctic control of glacial cycles. Because Earth is now passing again through a d 13 Cmax episode, it is crucial to understand the causal relationship between the successive d 13 C changes and ice-sheet growth events.
TL;DR: An AGU Chapman Conference on Continent-Ocean Interactions within the East Asian Marginal Seas as mentioned in this paper examined the nature of these interactions in the marginal seas of east Asia, and highlighted recent advances, and especially the contributions made by the Ocean Drilling Program (ODP)semi.
Abstract: Interactions between continents and oceans are a frontier area for the Earth sciences in the 21st century. An AGU Chapman Conference, Continent-Ocean Interactions within the East Asian Marginal Seas, examined the nature of these interactions in the marginal seas of east Asia. The objective was to highlight both recent advances, and especially the contributions made by the Ocean Drilling Program (ODP)semi; as well as to identify key future science goals. The types of continent-ocean interactions discussed were wide-ranging, including climate-tectonic interactions, continental-oceanic climate linkages, and the material flux from the rivers of Asia to the ocean, as well as how continental tectonic evolution since the India-Asia collision has influenced the tectonics of the western Pacific and vice-versa. The marginal seas of east Asia form the transition between the world's largest continent and its largest ocean, and are major repositories of information on the interaction between the two.
TL;DR: In this article, mineral chemistry data and petrological evidence from the Yarlung Zangbo suture zone ophiolites (Southern Tibet) were presented, suggesting that they represent a collage of heterogeneous massifs.
Abstract: We present mineral chemistry data and petrological evidence from the Yarlung Zangbo suture zone ophiolites (Southern Tibet)
suggesting that they represent a collage of heterogeneous massifs. Mantle sections in these ophiolites consist of harzburgite
and lherzolite cut by several generations of gabbroic to diabasic intrusions, all affected by high-temperature deformation.
Pyroxenitic bands are parallel to the mantle foliation. Crustal plutonic sections, consisting of dunite, wehrlite and gabbro,
are thin or absent and have been observed only in the Dazhuqu massif. Plagioclase is an additional phase associated with crustal
peridotites. The mineral chemistry of silicate minerals and spinel in the mantle and crustal rocks varies widely and is believed
to reflect complex melt percolation and reaction. The massifs record polybaric exhumation steps from at least 50 km depth
to the plagioclase stability field. Pyroxene has re-equilibrated compositions from 1200 °C down to medium-grade metamorphic
conditions. The mantle peridotites are interpreted as the residues of 10–40% partial melting of a fertile lherzolitic source.
High Cr number, low TiO 2 content and relatively high Fe 3+ number of spinels suggest that the ophiolitic massifs were generated in a suprasubduction zone (arc or back-arc) environment.
TL;DR: In this paper, the influence of different agents such as DDTC, diethylammonium diethyldithiocarbamate (DDC) and ammonium pyrrolidinedinedithiamine (APDC) on the precipitation and flocculation of Cu2+ cation is studied in details, such as the amount of complex copper (EDTA and NH4Cl are used as coordination agents), the addition of DDTC and poly-ferric sulphate and polyacrylamide (PAM) and pH of the solution.
TL;DR: In this article, the authors conducted an integrated palaeomagnetic and stratigraphic study on a 5452.8 m thick sedimentary sequence of the Hoh Xil Basin in northern Qinghai-Tibet Plateau to obtain a chronostratigraphic framework for these sediments.
Abstract: SUMMARY We conducted an integrated palaeomagnetic and stratigraphic study on a 5452.8 m thick sedimentary sequence of the Hoh Xil Basin in northern Qinghai-Tibet Plateau to obtain a chronostratigraphic framework for these sediments. A total of 966 individual oriented palaeomagnetic samples (spaced at stratigraphic intervals) were collected from six measured sections in the Hoh Xil Basin. Magnetic directions in these samples were obtained by progressive thermal (mainly) and alternating-field demagnetization experiments. Most samples exhibit two components of magnetization. The lower unblocking temperature component is an overprint resembling the present-day geocentric axial dipole field direction at the sampling locality. The most stable, characteristic remanence (ChRM) appears to be an early chemical remanent magnetization residing mainly in haematite. The positive results of fold and reversal tests indicate that the ChRM is a record of the palaeomagnetic field close to the time of formation of these sediments. Further evidence for the magnetization of these sediments acquired close to their time of deposition is the fact that patterns of magnetic reversals can be matched with the established polarity timescale. On the basis of the distinct interval of magnetic reversal zones and biostratigraphic datums, 13 magnetozones can be recognized at the Hoh Xil Basin that range from chrons C11 to C23 (30.1‐51.0 Ma). The age of the Fenghuoshan Group is palaeomagnetically dated as 51‐31 Ma (Early Eocene‐Middle Early Oligocene), and the age of the Yaxicuo Group is between 31 and 30 Ma (Middle Early Oligocene‐Late Early Oligocene). The new palaeomagnetic data from the Fenghuoshan Group suggest that it has undergone no significant rotation since the Oligocene. In contrast, declination data from the Yaxicuo Group in Wudaoliang area imply a vertical-axis clockwise rotation (29.1 ◦ ± 8.5 ◦ ) since the Late Oligocene. The Tertiary palaeomagnetic pole position of the Hoh Xil Basin implies a significant northward convergence of the Hoh Xil Basin (∼1600 km) with respect to Eurasia (Siberia) since Early Eocene‐Late Oligocene time. Our results are consistent with the pattern of disturbingly low palaeolatitudes derived from a large number of high-quality palaeomagnetic studies of Tertiary rocks from sites that reach all the way from eastern China to Kyrgyzstan. Future work is needed to separate the influences of sedimentary inclination shallowing and tectonic shortening.
TL;DR: In this article, a comparison between the bulk and acid-leached sediments indicates that about 20∼30% of the Al, K, Sc and Ti in the bulk sediments are not hosted in terrestrial detritus, rather they are of authigenic origin.
Abstract: Al, K, Sc and Ti concentrations of the terrestrial material-dominant sediments from ODP site 1144 were reported. Comparison between the bulk and the acid-leached sediments indicates that about 20∼30% of the Al, K and Sc in the bulk sediments are not hosted in terrestrial detritus, rather they are of authigenic origin. However, authigenic Ti is negligible. The results indicate that Ti rather than Al is the best proxy for terrestrial materials. Significant climate controls are displayed in the Al/Ti, K/Ti and Sc/Ti variation patterns both for the bulk and the acid leached sediments. Such variation patterns can be mainly accounted for in terms of climate change in their provenance areas in South China. Elevated Al/Ti, K/Ti and Sc/Ti ratios during interglacial periods indicate that chemical weathering then was stronger than during glacial periods, which might be related to a more humid climate in interglacial periods.
TL;DR: In this paper, a simple process was proposed based on a combination of chemical and physical activation for the production of activated carbon, which was expected to improve the mesoporosity in activated carbons.