Showing papers by "Nanjing University published in 2001"
TL;DR: The record links North Atlantic climate with the meridional transport of heat and moisture from the warmest part of the ocean where the summer East Asian Monsoon originates and generally agrees with the timing of temperature changes from the Greenland Ice Sheet Project Two (GISP2).
Abstract: Oxygen isotope records of five stalagmites from Hulu Cave near Nanjing bear a remarkable resemblance to oxygen isotope records from Greenland ice cores, suggesting that East Asian Monsoon intensity changed in concert with Greenland temperature between 11,000 and 75,000 years before the present (yr. B.P.). Between 11,000 and 30,000 yr. B.P., the timing of changes in the monsoon, as established with 230Th dates, generally agrees with the timing of temperature changes from the Greenland Ice Sheet Project Two (GISP2) core, which supports GISP2's chronology in this interval. Our record links North Atlantic climate with the meridional transport of heat and moisture from the warmest part of the ocean where the summer East Asian Monsoon originates.
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TL;DR: In this article, a hemoglobin (Hb) was immobilized successfully on nanometer-sized gold colloid particles associated with a cysteamine monolayer on a gold electrode surface.
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328 citations
TL;DR: In this article, the authors presented the results of a study examining the backscatter behavior of rice as a function of time using multitemporal RADARSAT data acquired in 1996 and 1997.
322 citations
TL;DR: The most remarkable structural variations and the associated atomic charge variations in the hydrolysis process were found to occur in the equatorial plane of the five-coordinate trigonal-bipyramidal (TBP)-like structures of I1, TS, and I2.
Abstract: Hydrolysis of cisplatin, the most widely used anticancer drug in the world, is believed to be the key activation step before the drug reaching its intracellular target DNA.To obtain an accurate hydrolysis theory for this important class of square-planar Pt(II) complexes, three typical reactions, i.e., the first and second hydrolyses of cisplatin and the hydrolysis of [Pt(dien)Cl]+ (dien = diethylenetriamine), were studied at the experimental temperature with the solvent effect using mPW1PW91/SDD from a comprehensive methodological study on the Hartree−Fock (HF) ab initio method, electron correlation methods, pure density functional theory (DFT) methods, and hybrid HF-DFT methods with several basis sets. The true five stationary states in the second-order nucleophilic substitution (SN2) pathway for the hydrolysis process, namely, reactant (R) → intermediate 1 (I1) → TS → intermediate 2 (I2) → product (P) were obtained and characterized theoretically for the first time. The most remarkable structural variat...
290 citations
TL;DR: Experimental results have shown that lower pH and higher concentration of dissolved oxygen favor the phenol degradation and that the presence of Fe2+ enhanced TOC removal of phenol solutions.
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TL;DR: Out of 39 endophytes investigated, 21 can produce in vitro substances that are inhibitory to all or a few of the tested phytopathogens whereas the rest yielded nothing active.
TL;DR: It was found that alteration of pH value and redox potential might affect the change of La, Ce, Gd and Y species in the soil as well as the influence ofredox potential on Ce was more remarkable than on La, GD and Y.
TL;DR: In this article, the authors studied the features of the closed-aperture (CA) Z-scan transmittance curves when the third-order nonlinear refraction and absorption, both of which can be independently positive or negative, are simultaneously present.
TL;DR: An interesting feature of this analysis rests with the fact that an open raceways is as effective in productivity per illuminated area as a flat-plate reactor with an optimal light path, both cultivation systems requiring ca.
TL;DR: A novel ZVZCS TL converter is proposed, its operation principle and parameter design are analyzed, and the experimental results are also included.
Abstract: This paper proposes a family of modulation strategies for PWM three-level (TL) converters. The modulation strategies can be classified into two kinds according to the turn-off sequence of the two switches of the pair of switches. The concept of the leading switches and the lagging switches is introduced to realize soft-switching for PWM TL converters. The realization of soft-switching for both the leading switches and the lagging switches is proposed, based on which, soft-switching PWM TL converters can be classified into two kinds: zero-voltage-switching (ZVS) and zero-voltage and zero-current-switching (ZVZCS), for which the suitable modulation strategies are pointed out respectively from the family of modulation strategies. A novel ZVZCS TL converter is proposed, its operation principle and parameter design are analyzed, and the experimental results are also included.
TL;DR: The results of these studies indicate that phytotoxicity of substituted phenols and anilines to C. sativus seeds could be explained by a polar narcosis mechanism, which will provide the fundamental data for QSAR and ecological risk assessment of organic pollutants.
TL;DR: The structures of free-standing gold nanowires are studied by using molecular-dynamics-based genetic algorithm simulations, and bulklike behaviors are found for the vibrational and electronic properties of the nanowire with fcc crystalline structure.
Abstract: The structures of free-standing gold nanowires are studied by using molecular-dynamics-based genetic algorithm simulations. Helical and multiwalled cylindrical structures are found for the thinner nanowires, while bulk-like fcc structures eventually form in the thicker nanowires up to 3 nm in diameter. This noncrystalline-crystalline transition starts from the core region of nanowires. The vibrational, electronic, and transport properties of nanowires are investigated based on the optimal structures. Bulklike behaviors are found for the vibrational and electronic properties of the nanowires with fcc crystalline structure. The conductance of nanowires generally increases with wire diameter and depends on the wire structure.
TL;DR: According to the direct electron-transfer property and enhanced peroxidase activity of Hb in the membrane, a Hb/SP Sephadex membrane-based H2O2 biosensor is prepared, with a linear range approximately 5.0 x 10(-6) to 1.6 x 10 (-4) mol/L.
Abstract: Hemoglobin can exhibit a direct electron-transfer reaction after being entrapped in a SP Sephadex membrane A pair of stable and well-defined redox waves are obtained at a hemoglobin−SP sephadex mo
TL;DR: In this paper, the authors examined the human impacts on the major hydrological processes in the Changjiang River basin, with a special focus on their influence on the discharge from the drainage basin to the sea during the dry season.
TL;DR: An economic appraisal is provided for operating a 2000-l reactor, sufficient to supply all the algal mass for production of the rotifer quantity required by a Seabream hatchery producing 8×10 6 fingerlings annually.
TL;DR: In this article, the geometrical and electronic structures of the germanium clusters with up to 25 atoms were studied by using density-functional theory with the generalized gradient approximation, and two kinds of competing structures, stacked layered structures and compact structures, were found.
Abstract: The geometrical and electronic structures of the germanium clusters with up to 25 atoms are studied by using density-functional theory with the generalized gradient approximation. The ${\mathrm{Ge}}_{n}$ clusters follow a prolate growth pattern with $ng~13.$ For medium-sized clusters, we find two kinds of competing structures, stacked layered structures and compact structures. The stacked layered structures with capped tetrahedron ${\mathrm{Ge}}_{9}$ cluster are more stable than compact structures and other stacked structures. The size dependence of cluster binding energies, highest-occupied and lowest-unoccupied molecular orbital gap, and ionization potentials are discussed and compared with experiments.
TL;DR: A novel phase-shifted zero-voltage and zero-current-switching (ZVZCS) pulsewidth modulation full-bridge converter, which realizes ZVS for the leading leg and ZCS for the lagging leg is proposed.
Abstract: This paper proposes a novel phase-shifted zero-voltage and zero-current-switching (ZVZCS) pulsewidth modulation full-bridge converter, which realizes ZVS for the leading leg and ZCS for the lagging leg. A blocking capacitor is added in series with the primary winding of the transformer to make the primary current decay to zero during zero state to ensure ZCS for the lagging leg. In order to prevent the primary current from reversing during zero state, two diodes in series with the lagging leg are added. The principle of operation, steady-state analysis, and design procedures are presented. The experimental results are also included to verify the theoretical analysis.
TL;DR: Amberlite XAD-4 polymeric resins were chemically modified with an acetyl group, which enables the resin to be used directly without a wetting process as discussed by the authors.
Abstract: Amberlite XAD-4 polymeric resin was chemically modified with an acetyl group, which enables the resin to be used directly without a wetting process. The modified resin was comparatively evaluated using four phenolic compounds, phenol, p-cresol, p-chlorophenol, and p-nitrophenol. The capacities of equilibrium adsorption for all four phenolic compounds from their aqueous solutions increased around 20% on the acetylated resins within temperature range of 283–323 K. Freundlich isotherm equations, as well as the relative adsorptive capacities and isosteric adsorption enthalpies for the four phenolic compounds, indicate a physical and multiple-layer adsorption process on the Amberlite XAD-4 resins either with or without the chemical modification. Mini-column adsorption studies showed that the breakthrough adsorption capacity and the total adsorption capacity at designated conditions for all four phenolic compounds also increased over 20% after chemical modification.
TL;DR: In this article, a set of nanocrystalline CeO2 powders of size 2.0 nm displaying quantum size effects have been prepared by======¯¯¯¯microwave irradiation in an aqueous solution containing======(NH4)2Ce(NO3)6, PEG and======€€ 1€ 6€ 2.
TL;DR: In this article, the authors derived light curves of the afterglow emission from highly collimated jets if the power-law index (p )o f the electron energy distribution is above 1 but below 2.
Abstract: We derive light curves of the afterglow emission from highly collimated jets if the power-law index (p )o f the electron energy distribution is above 1 but below 2. We find the following: (1) Below the characteristic synchrotron frequency, the light-curve index depends generally on p. (2) As long as the jet expansion is spherical, the light-curve index above the characteristic frequency increases slowly as the spectral index of the emission increases. (3) Once the jet enters the spreading phase, the high-frequency emission flux decays as proportional to rather than proportional to . All these results differ from those in the case of . We compare ( p6)/4 p tt p 1 2 our analytical results with the observations on the GRB 010222 afterglow and conclude that the jet model may be unable to explain the observed data. Thus, a more promising explanation for this afterglow seems to be the expansion of a relativistic fireball or a mildly collimated jet in a dense medium. Subject headings: gamma rays: bursts — relativity — shock waves
TL;DR: In this paper, a simple one-step solid-state reaction in the presence of a suitable surfactant has been developed to synthesize uniform copper oxide nanorods with average diameters of ca. 8 nm and lengths of up to 400 nm.
TL;DR: The results demonstrate that the molecular M3L2 type cage can act as a host for anions and provide a nice example of supramolecular architectures with interesting properties and possible applications.
Abstract: Three five-component archi- tectures, compounds 3, 4, and 5 were obtained by self-assembly of tripodal 1,3,5-tris(imidazol-1-ylmethyl)-2,4,6-tri- methylbenzene (6) and 1,3,5-tris(benz- imidazol-2-ylmethyl)benzene (7) li- gands with silver(i) salts. The structures of these novel complexes have been determined by X-ray crystallography. The results of structural analysis indicate that these frameworks have same M3L2 components, but different structures. Compounds 3 and 4 are both M3L2 type cage-like complexes, while the 5 is an open trinuclear complex. The complex 3 is a cylindrical cage with simultaneous inclusion of a perchlorate anion inside of the cage as a guest molecule. Such guests can be exchanged for other anions through the open edge of the cage as evidenced by crystal structure of 4 .T he results demonstrate that the molecular M3L2 type cage can act as a host for anions and provide a nice example of supramolecular architectures with inter- esting properties and possible applica- tions.
TL;DR: In this paper, a simple reaction between CdCl 2 or Zn(Ac) 2 and thioacetamide in aqueous solution using microwave irradiation has been described.