Showing papers by "Wuhan University published in 2001"
TL;DR: Global Positioning System (GPS) measurements in China indicate that crustal shortening accommodates most of India's penetration into Eurasia, but the Tibetan plateau south of the Kunlun and Ganzi-Mani faults is moving eastward relative to both India and Eurasia.
Abstract: Global Positioning System (GPS) measurements in China indicate that crustal shortening accommodates most of India's penetration into Eurasia. Deformation within the Tibetan Plateau and its margins, the Himalaya, the Altyn Tagh, and the Qilian Shan, absorbs more than 90% of the relative motion between the Indian and Eurasian plates. Internal shortening of the Tibetan plateau itself accounts for more than one-third of the total convergence. However, the Tibetan plateau south of the Kunlun and Ganzi-Mani faults is moving eastward relative to both India and Eurasia. This movement is accommodated through rotation of material around the eastern Syntaxis. The North China and South China blocks, east of the Tibetan Plateau, move coherently east-southeastward at rates of 2 to 8 millimeters per year and 6 to 11 millimeters per year, respectively, with respect to the stable Eurasia.
1,019 citations
TL;DR: In this article, the influence of coagulation solution composition on the spinning performance was discussed and the intermolecular interactions of blend fibers were studied by infrared analysis (IR), X-ray diffraction (XRD), and scanning electron micrograph (SEM) and by measurements of mechanical properties and water-retention properties.
Abstract: Chitosan and poly(vinyl alcohol) blend fibers were prepared by spinning their solution through a viscose-type spinneret at 25°C into a coagulating bath containing aqueous NaOH and ethanol. The influence of coagulation solution composition on the spinning performance was discussed, and the intermolecular interactions of blend fibers were studied by infrared analysis (IR), X-ray diffraction (XRD), and scanning electron micrograph (SEM) and by measurements of mechanical properties and water-retention properties. The results demonstrated that the water-retention properties and mechanical properties of the blend fibers increase due to the presence of PVA in the chitosan substract, and the mechanical strength of the blends is also related to PVA content and the degree of deacetylation of chitosan. The best mechanical strength values of the blend fibers, 1.82 cN/d (dry state) and 0.81 cN/d (wet state), were obtained when PVA content was 20 wt % and the degree of deacetylation of chitosan was 90.2%. The strength of the blend fibers, especially wet tenacity could be improved further by crosslinking with glutaraldehyde. The water-retention values (WRV) of the blend fibers were between 170 and 241%, obviously higher than pure chitosan fiber (120%). The structure analysis indicated that there are strong interaction and good miscibility between chitosan and poly(vinyl alcohol) molecular resulted from intermolecular hydrogen bonds. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 2558–2565, 2001
239 citations
TL;DR: In this article, the dissolution of cellulose and the structure, transparency, and mechanical properties of regenerated cellulose (RC) films were investigated by 13C NMR, ultraviolet, and infrared spectroscopies; scanning electron microscopy; X-ray diffraction; and a strength test.
Abstract: Regenerated cellulose (RC) films having various viscosity-average molecular weights (Mη) ranging from 2.2 × 104 to 8.2 × 104 g/mol were prepared from cotton linters in 6 wt % NaOH/4 wt % urea aqueous solution by coagulation with 2 M acetic acid and 2% H2SO4 aqueous solution. The dissolution of cellulose and the structure, transparency, and mechanical properties of the RC films were investigated by 13C NMR, ultraviolet, and infrared spectroscopies; scanning electron microscopy; X-ray diffraction; and a strength test. The RC films exhibited the cellulose II crystalline form and a homogeneous structure with 85% light transmittance at 800 nm. 13C NMR spectroscopy indicated that the presence of urea in NaOH aqueous solution significantly enhanced the intermolecular hydrogen bonding between cellulose and the solvent, resulting in a higher solubility of cellulose and the complete transition of its crystalline form from I to II. The tensile strength (σb) of the RC films in the dry state increased with increasing ...
204 citations
TL;DR: In this article, a damping Hamiltonian system perturbed by a random force is considered and the locally uniform large deviation principle of Donsker and Varadhan is established for its occupation empirical measures for large time.
202 citations
TL;DR: A molecular marker-based genetic analysis of the BPH resistance of ’B5’, a highly resistant line that derived its resistant genes from the wild rice Oryza officinalis, indicated that these two genes are different from at least nine of the ten previously identified B PH resistance genes.
Abstract: The brown planthopper (BPH) is one of the most serious insect pests of rice. In this study, we conducted a molecular marker-based genetic analysis of the BPH resistance of ’B5’, a highly resistant line that derived its resistant genes from the wild rice Oryza officinalis. Insect resistance was evaluated using 250 F3 families from a cross between ’B5’ and ’Minghui 63’, based on which the resistance of each F2 plant was inferred. Two bulks were made by mixing, respectively, DNA samples from highly resistant plants and highly susceptible plants selected from the F2 population. The bulks were surveyed for restriction fragment length polymorphism using probes representing all 12 chromosomes at regular intervals. The survey revealed two genomic regions on chromosome 3 and chromosome 4 respectively that contained genes for BPH resistance. The existence of the two loci were further assessed by QTL (quantitative trait locus) analysis, which resolved these two loci to a 14.3-cM interval on chromosome 3 and a 0.4-cM interval on chromosome 4. Comparison of the chromosomal locations and reactions to BPH biotypes indicated that these two genes are different from at least nine of the ten previously identified BPH resistance genes. Both of the genes had large effects on BPH resistance and the two loci acted essentially independent of each other in determining t he resistance. These two genes may be a useful BPH resistance resource for rice breeding programs.
197 citations
TL;DR: In this article, the authors studied the time-asymptotic behavior of solutions for the isentropic Euler equations with damping in multi-dimensions and obtained the global existence and pointwise estimates of the solutions.
187 citations
TL;DR: A number of related methodologies, applications, and policy considerations were examined in this article for sustainable water-quality management in the twenty-first century, including data availability and reliability, concerns in system complexity and methodology validity, limitations of computer techniques, usefulness of research outputs, difficulties in policy implementation, and necessity of training programs.
183 citations
TL;DR: In this paper, it was shown that unless all points have the same ergodic limit, then the set of points whose ergodics limit does not exist has the same topological entropy as the whole space.
Abstract: Let ([sum ]A, T) be a topologically mixing subshift of finite type on an alphabet consisting of m symbols and let Φ:[sum ]A → Rd be a continuous function. Denote by σΦ(x) the ergodic limit limn→∞n−1 [sum ]n−1j=0 Φ(Tjx) when the limit exists. Possible ergodic limits are just mean values ∫ Φdμ for all T-invariant measures. For any possible ergodic limit α, the following variational formula is proved:[formula here]where hμ denotes the entropy of μ and htop denotes topological entropy. It is also proved that unless all points have the same ergodic limit, then the set of points whose ergodic limit does not exist has the same topological entropy as the whole space [sum ]A
174 citations
TL;DR: A novel PNIPA gel was synthesized by using ethylene triethoxy silane (ETEOS) as the cross-linking agent under acidic conditions and this siloxane incorporated PNipA gel achieves a dramatically rapid response rate when the external temperature is changed.
Abstract: A gel is a water-insoluble polymeric material though it can absorb a lot of water in its network structure. The poly(N-isopropylacrylamide) (PNIPA) gel exhibits a change in volume in response to external temperature changes and this property is useful in many fields. In this manuscript, a novel PNIPA gel was synthesized by using ethylene triethoxy silane (ETEOS) as the cross-linking agent under acidic conditions. This siloxane incorporated PNIPA gel achieves a dramatically rapid response rate when the external temperature is changed. We suggest that the improvement of the response rate could be due to the macroporous structure of the produced polymer network during the polymerization/cross-linking process. This macroporous structure can provide interconnected water release channels and prevent the formation of a dense, thick skin layer at the shrinking course. On the other hand, water can also diffuse into the polymer network through these water channels during the reswelling process.
172 citations
TL;DR: The fluorescence microscopy experiment suggests the benefit the more uniform surface of the sol-gel-derived OHDB14C4/OH-TSO fiber in comparison with sol-gelderived OH-DB 14C4 fiber.
Abstract: A novel solid-phase microextraction (SPME) fiber containing hydroxydibenzo-14-crown-4 (OH-DB14C4)/hydroxy-terminated silicone oil (OH-TSO) was first prepared by a sol−gel method and investigated for the determination of phenols. The possible mechanism is discussed and confirmed by IR spectra. The coating has stable performance in high temperature (to 350 °C) and solvents (organic and inorganic) due to the chemical binding between the coating and the fiber surface. The addition of crown ether enhances the polarity of the coating compared with that of the sol−gel OH-terminated silicone oil fiber and, accordingly, provides higher extraction efficiency for polar phenolic compounds. On the other hand, OH-terminated silicone oil in the coating can not only increase the length of network but also help to spread the stationary phase on the silica surface uniformly. The fluorescence microscopy experiment suggests the benefit the more uniform surface of the sol−gel-derived OH-DB14C4/OH-TSO fiber in comparison with ...
159 citations
09 Jul 2001
TL;DR: In this article, an index called vegetation temperature condition index (VTCI) was developed for drought monitoring in the Guanzhong Plain area of the Loess Plateau in the Northwest China, and the results showed that VTCI had better performances in classifying the relative drought occurrence levels and in studying the distribution of drought occurrences.
Abstract: An index called vegetation temperature condition index (VTCI) was developed for drought monitoring in this study. The index can be used to monitor drought occurrences at a regional level for a special period (e.g. 10 days) of a year, and can be also used to study the spatial distribution of drought within the region. VTCI is not only related to NDVI changes in the region, but also related to land surface temperature changes of pixels with the same NDVI value. A pilot study was carried out for drought monitoring in the Guanzhong Plain area of the Loess Plateau in the Northwest China. The results showed that VTCI had better performances in classifying the relative drought occurrence levels and in studying the distribution of drought occurrences.
TL;DR: A new method for the determination of 4-nitrophenol(4-NP) by differential pulse voltammetry (DPV) based on adsorptive stripping technique was described, and the interference of organic and inorganic species on the voltammetric response have been studied.
TL;DR: In this article, a microcolumn packed with nanometer TiO 2 as solid phase extractant has been developed for the simultaneous preconcentration of trace amounts of Cu, Mn, Cr and Ni prior to their measurements by inductively coupled plasma atomic emission spectrometry (ICP-AES).
TL;DR: Empirical comparisons of the predictive accuracy, in terms of the model efficiency R2 and absolute relative errors (ARE), between the RDNN, back-propagation networks and the threshold auto-regressive (TAR) model are made and it is demonstrated that theRDNN network performed significantly better than the BP network, especially for reproducing low-flow events.
Abstract: Artificial neural networks provide a promising alternative to hydrological time series modelling. However, there are still many fundamental problems requiring further analyses, such as structure identification, parameter estimation, generalization, performance improvement, etc. Based on a proposed clustering algorithm for the training pairs, a new neural network, namely the range-dependent neural network (RDNN) has been developed for better accuracy in hydrological time series prediction. The applicability and potentials of the RDNN in daily streamflow and annual reservoir inflow prediction are examined using data from two watersheds in China. Empirical comparisons of the predictive accuracy, in terms of the model efficiency R2 and absolute relative errors (ARE), between the RDNN, back-propagation (BP) networks and the threshold auto-regressive (TAR) model are made. The case studies demonstrated that the RDNN network performed significantly better than the BP network, especially for reproducing l...
TL;DR: In this article, the negative association between decentralization and provincial economic growth has been consistently significant and robust in China, while in India, it has been shown that decentralization is positively associated with state economic growth.
TL;DR: The isolated ASY gene encodes an endoplasmic reticulum-targeting protein without any known apoptosis-related motifs, which is identical to the Nogo-B, a splice variant of theNogo-A which has recently been shown to be an inhibitor of neuronal regeneration in the central nervous system.
Abstract: Although apoptosis plays an essential role in the embryogenesis and homeostasis of multicellular organisms, this mechanism has not yet been fully clarified. We isolated a novel human apoptosis-inducing gene, ASY, which encodes an endoplasmic reticulum-targeting protein without any known apoptosis-related motifs. This gene is identical to the Nogo-B, a splice variant of the Nogo-A which has recently been shown to be an inhibitor of neuronal regeneration in the central nervous system. Ectopic expression of the ASY gene led to extensive apoptosis, particularly in cancer cells. Furthermore, transcription of the ASY gene was suppressed in small cell lung cancer. These results suggest that a new type of apoptosis-inducing gene, namely, ASY, may be involved in the development of certain types of cancer.
TL;DR: In this article, a micro-column packed with nanometer sized TiO2 as a sorbent has been developed for the on-line preconcentration of trace amounts of rare earth elements (La, Y, Yb, Eu and Dy) prior to their determination by inductively coupled plasma atomic emission spectrometry (ICP-AES).
Abstract: A new method using a micro-column packed with nanometer sized TiO2 as a sorbent has been developed for the on-line preconcentration of trace amounts of rare earth elements (La, Y, Yb, Eu and Dy) prior to their determination by inductively coupled plasma atomic emission spectrometry (ICP-AES). The effects of pH, sample flow rate and volume, elution solution and interfering ions on the separation of analytes have been investigated. The adsorption capacity of nanometer TiO2 for La, Y, Yb, Eu and Dy was found to be 7.0, 6.1, 9.8, 8.3 and 8.8 mg g−1, respectively. The method has been successfully applied for the determination of trace rare earth elements in some environmental samples.
TL;DR: The sol-gel-derived hydroxy-dibenzo14-crown-4-coated fiber has the best affinity for several aniline derivatives and was applied to the determination of aromatic amines in wastewater samples from a pharmaceutical factory.
TL;DR: A new voltammetric method for the determination of phenol is described, which has a very sensitive oxidation peak at 0.47 V (vs. SCE) on the Nafion-modified glassy carbon electrode (GCE).
TL;DR: The grain size and surface hydroxyl content of super-hydrophilic TiO2/SiO2 composite nanometer thin films were investigated in this paper, where the authors used a state key laboratory of Advanced Technology for Materials Synthesis and Processing at Wuhan University of Technology.
Abstract: The grain size and surface hydroxyl content of super-hydrophilic TiO2/SiO2 composite nanometer thin films JIAGUO YU∗ State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, Wuhan, 430070, People’s Republic of China; Department of Chemistry, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong, People’s Republic of China E-mail: yujiaguo@public.wh.hb.cn
TL;DR: In this article, the properties of calcium zincate as negative electrode materials for secondary batteries were examined by powder microelectrode, cyclic voltammetry, charge-discharge cycle measurements and X-ray diffraction (XRD) analysis.
TL;DR: The experimental results showed that the CFMEs and CFNEs have very excellent electrochemical behavior and high sensitivity and the noise caused by the glass/fiber of these electrodes is much lower than that of the electrodes fabricated conventionlly.
Abstract: A new and facile method has been developed for the fabrication of low-noise carbon fiber microelectrodes (CFMEs) and carbon fiber nanoelectrodes (CFNEs). The carbon fiber was flame-fuse sealed in the tip of the glass capillary. The CFMEs were made by cutting the protruding carbon fiber to the desired length, and the CFNEs were achieved by etching the protruding carbon on the flame to form a nanometer-scale tip. The tip of CFNEs can be controlled within the range from 100 to 300 nm. Thus, no epoxy wax was involved in the CFMEs and CFNEs. The experimental results of inspecting CFMEs and CFNEs by scanning electron microscopy demonstrated that the surface of the electrodes and the glass/fiber interface are very smooth. Therefore, the noise caused by the glass/fiber of these electrodes is much lower than that of the electrodes fabricated conventionlly. The electrodes were characterized by ferricyanide, catecholamine (dopamine,DA), norepinephrine (NE), and epinephrine (E)) and 5-hydroxytryptamine (5-HT) neurotr...
TL;DR: Three strains of alkalophilic bacteria, Bacillus sp.
TL;DR: In this paper, the authors consider the iterated function systems of similitudes which satisfy a separation condition weaker than the open set condition, in that it allows overlaps in the iteration.
Abstract: The paper considers the iterated function systems of similitudes which satisfy a separation condition weaker than the open set condition, in that it allows overlaps in the iteration. Such systems include the well-known Bernoulli convolutions associated with the PV numbers, and the contractive similitudes associated with integral matrices. The latter appears frequently in wavelet analysis and the theory of tilings. One of the basic questions is studied: the absolute continuity and singularity of the self-similar measures generated by such systems. Various conditions to determine the dichotomy are given.
TL;DR: The kinetic aspects of powder material electrochemistry can be studied using the cavity microelectrode (CME) as it allows carrying out voltammetry at scan rates between a few millivolts per second to several hundreds of volts per second as discussed by the authors.
TL;DR: In this paper, the 2-position carbon atom in the substituted glucose unit of β-cyclodextrin and β-CD-2-CTS was characterized with infrared spectra analysis and X-ray diffraction.
Abstract: β-CD-2-CTS was synthesized by β-cyclodextrin reacting with p-toluenesulfonyl chloride, then grafting with chitosan. The infrared spectra analysis and 13C NMR confirmed that β-cyclodextrin reacted with p-toluenesulfonyl chloride at the 2-position carbon atom in the substituted glucose unit of β-cyclodextrin and formed β-CD-2-OTs. In the 13C NMR of β-CD-2-OTs, the characteristic peak of the 2-postion carbon atom in the substituted glucose unit of β-cyclodextrin appeared at 78.43 ppm. β-CD-2-CTS was characterized with infrared spectra analysis and X-ray diffraction. In the infrared spectra of β-CD-2-CTS, the characteristic peak of α-pyanyl vibration of β-CD was at 848.6 cm−1. The characteristic peak of β-pyanyl vibration of CTS was at 894.9 cm−1. The X-ray diffraction analysis showed that the peak at 2θ = 20° decreased greatly in β-CD-2-CTS. The polymer inclusion complex of β-CD-2-CTS with iodine was prepared and its inclusion ability was studied. The experimental results showed that a nice bit of iodine was included with β-CD-2-CTS and formed a stable inclusion complex. After the subcutaneous implantation of the polymer inclusion complex of β-CD-2-CTS with 131I2 in rats, 131I2 exhibited the property of slow release. 131I2 in the blood of rats decreased slowly. 131I2 in the blood of rats maintained approximately half of maximum for 70 days later, and maintained much higher radioactivity in the organs of rats compared to the inclusion complex of β-CD with 131 I2, too. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 2414–2421, 2001
TL;DR: In this paper, the structure and properties of the blend films were studied by infrared (IR) spectra, wide-angle X-ray diffraction (WAXD), scanning electron microscopy (SEM), thermogravimetric analysis (TGA), and differential thermal analysis (DTA).
Abstract: Blend films were prepared by blending 4 wt% sodium alginate and 5 wt% gelatin aqueous solutions and dried at room temperature for 2 days to obtain the transparent films. Their structures and properties were studied by infrared (IR) spectra, wide-angle X-ray diffraction (WAXD), scanning electron microscopy (SEM), thermogravimetric analysis (TGA), and differential thermal analysis (DTA). Significant changes in the shape and intensity of IR spectra absorption frequencies characteristic of either gelatin or sodium alginate were detected by IR analysis. The crystallinities of the blend films decreased with the increase of sodium alginate content. The thermal stability, mechanical properties of tensile strength, and breaking elongation of the blend films were improved by blending sodium alginate with gelatin. It is worth noting that the breaking elongation reached 16.6% when the weight ratio of sodium alginate to gelatin was 1:1, much higher than that of two components. The structure analysis indicated that the...
TL;DR: A spectrofluorimetric method for the determination of cysteine at trace and ultra trace levels (0-1.82 x 10(-5) mol l(-1)) has been developed and has been applied to protein hydrolysate and cystine electrolyte samples.
TL;DR: A series of manganese-containing mononuclear and binuclear model compounds of superoxide dismutase (SOD) coordinated by a polydentate ligand N,N, N′,N′-tetrakis(2′-benzimidazolyl methyl)-1,2-ethanediamine (EDTB) have been synthesized and characterized.
TL;DR: In this article, magnetic properties of quasi-two-dimensional thallium purple bronze were measured at different magnetic fields for H∥c and showed that the gap opening below TP still leaves small electron and/or hole pockets, but an applied magnetic field can remove these pockets to a great extent.
Abstract: Magnetotransport properties of quasi-two-dimensional thallium purple bronze were measured at different magnetic fields for H∥c. Huge positive magnetoresistance below the Peierls transition TP and Shubnikov-de Haas oscillation in the high-field range were found. In the charge-density-wave (CDW) state below TP, nonlinearity of the voltage-current characteristics due to the depinning of a CDW was also observed at 2 K and 14 T. These results supported the suggestion that the CDW gap opening below TP still leaves small electron and/or hole pockets, but an applied magnetic field can remove these pockets to a great extent, thus leading to an enhanced gap.