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1.
Guang Pu Xue Yu Guang Pu Fen Xi ; 33(2): 300-3, 2013 Feb.
Artículo en Zh | MEDLINE | ID: mdl-23697098

RESUMEN

The total partition function was calculated for carbon monoxide with approximation. Using the dipole moment function and the wave function with Morse approximation, we computed the matrix elements of vibrational-rotational transition and absorption coefficient at normal and high temperature. The computed results agreed with the HITRAN database and literature, which shows that the calculation of total partition function and matrix elements of vibrational-rotational transition is reliable. Furthermore, the absorption coefficient and radiant spectrum are also presented at higher temperature of 4 000 and 6 000 K.

2.
Huan Jing Ke Xue ; 41(6): 2714-2726, 2020 Jun 08.
Artículo en Zh | MEDLINE | ID: mdl-32608787

RESUMEN

Cycling dynamics of nitrogen in paddy rotation areas have a practical significance for ensuring food supply and realizing sustainable development of the regional ecology in the Min delta urban agglomeration. However, with rapid urbanization, the negative externalities of paddy rotation areas have been gradually increased because of unreasonable utilization behavior, and the environmental costs are increasing. Therefore, the spatial differentiation of nitrogen indicators and its driving factors were analyzed, which provides a macro-decision making basis for the implementation of farmland management measures. In this study, the paddy rotation area in Jinjiang River watershed was selected as the research object. The denitrification decomposition (DNDC) model was used to simulate the nitrogen cycle in the paddy rotation area. The hot spot analysis and geographical weight regression (GWR) model were used to analyze the spatial otherness characteristics and driving attribution of various nitrogen indices. The main results showed that: ① The DNDC model was validated by parameters, and the results showed preferably regional adaptability. ② Based on the comparison of different rotation patterns, the rice-vegetable rotation pattern not only established the maximum input of nitrogen fertilizer but also revealed the highest nitrogen absorption efficiency and the maximum values of nitrogen loss, followed by the rice-rice rotation pattern and rice-fallow rotation pattern. ③ In the spatial distribution of nitrogen indicators, except for the crop nitrogen absorption, the NH3 emission, N2O emission and nitrogen leaching showed a spatial clustering distribution, and the main trend line based on the standard deviation ellipse was mainly "Gande-Changkeng" township.④ According to the analysis of spatial influence factors for various nitrogen indices, soil attribute factors had the strongest effect; the SOCmax was the strongest influential factor for both NH3 and N2O emissions, and the spatial distribution was "west high, east low". The pHmin was the strongest influential factor in nitrogen leaching, and the spatial distribution was "north and south high, east and west low".


Asunto(s)
Nitrógeno/análisis , Oryza , Agricultura , Fertilizantes/análisis , Ríos , Rotación , Suelo
3.
Toxicon ; 45(6): 745-52, 2005 May.
Artículo en Inglés | MEDLINE | ID: mdl-15804523

RESUMEN

Experiments were conducted to investigate the degradation of microcystin-RR in order to assess the effectiveness and feasibility of the combined UV/H(2)O(2) catalytic system for purification of water polluted by microcystins. The operating parameters such as hydrogen peroxide dosage, pH value, UV light intensity, initial concentration of microcystin-RR and reaction time were evaluated, respectively. The degradation efficiency increased nonlinearly with increasing UV light intensity and hydrogen peroxide dosage, respectively. There existed an optimal hydrogen peroxide dosage, beyond which the reagent exhibited an inhibitory effect, for degrading microcystin-RR. The degradation process could be fitted by both of the pseudo-first-order and second-order kinetics well and primarily followed a mechanism of both direct photolysis and hydroxyl radical oxidation. Compared with the treatment using UV radiation and hydrogen peroxide individually, the combined UV/H(2)O(2) system could significantly enhance the degradation efficiency due to the synergetic effect between UV radiation and hydrogen peroxide oxidation. The observed rate constants decreased and the corresponding half-lives prolonged as the concentrations of microcystin-RR increased. The combined UV/H(2)O(2) process provides an effective technology for the removal of microcystins from drinking water supplies.


Asunto(s)
Cianobacterias/química , Peróxido de Hidrógeno/química , Péptidos Cíclicos/química , Rayos Ultravioleta , Purificación del Agua/métodos , Cromatografía Líquida de Alta Presión , Concentración de Iones de Hidrógeno , Cinética , Toxinas Marinas , Microcistinas , Oxidación-Reducción , Fotólisis
4.
J Hazard Mater ; 118(1-3): 219-25, 2005 Feb 14.
Artículo en Inglés | MEDLINE | ID: mdl-15721547

RESUMEN

In this paper, reactive brilliant X-3B was used as a model compound to study the photocatalytic activity of TiO2. Experimental results showed that the adulteration of iron and silver on TiO2 could greatly improve the activity of TiO2, and the optimum adulteration amount of iron and silver was 0.1 wt.% (Fe/TiO2) and 0.05 wt.% (Ag/TiO2), respectively, at the adulteration range of experiments. The photocatalytic degradation kinetics of X-3B on TiO2, Fe/TiO2 and Ag/TiO2 were also studied. The results showed that the degradation of X-3B on all of them were in accordance with the Langmiur-Hinshelwood kinetics model well, and the sequence of apparent reaction rate constants k of X-3B degradation catalyzed by TiO2, Fe/TiO2 and Ag/TiO2 was Ag/TiO2>Fe/TiO2>TiO2, while adsorption equilibrium constants KA of X-3B on Fe/TiO2 and Ag/TiO2 were approximately the same, and both were greater than that of TiO2.


Asunto(s)
Compuestos Azo/química , Colorantes/química , Titanio/química , Eliminación de Residuos Líquidos/métodos , Adsorción , Catálisis , Cinética , Fotoquímica , Industria Textil , Purificación del Agua
5.
J Hazard Mater ; 90(1): 51-62, 2002 Feb 14.
Artículo en Inglés | MEDLINE | ID: mdl-11777592

RESUMEN

The decomposition of aniline in supercritical water (SCW) was studied. Experiments were performed at various temperatures, pressures, residence times, dosage of oxidant H2O2 and initial aniline concentrations to investigate their effect on the destruction efficiency. Manganous sulfate and ferrous sulfate were screened out during the experiment to study the effect of the homogenous catalysts on destruction efficiency. The effect of pH was also studied. The experiments showed that the dosage of oxidant H2O2, experimental temperature, pressure, reaction residence time and even initial concentration of the aniline in wastewater have a significant affect on the TOC removal; manganous sulfate and ferrous sulfate improve the oxidation; TOC removal improves slightly with a decrease in the initial pH value. At a system temperature 450 degrees C, pressure 28 MPa, initial pH 4.0, residence time 46 s and K value 1.1, TOC removal can reach 100%.


Asunto(s)
Compuestos de Anilina/química , Carcinógenos/química , Eliminación de Residuos Líquidos , Agua/química , Catálisis , Peróxido de Hidrógeno/química , Concentración de Iones de Hidrógeno , Oxidantes/química , Oxidación-Reducción , Oxígeno , Presión , Temperatura , Contaminantes del Agua
6.
Neurosci Bull ; 30(6): 923-935, 2014 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-25391447

RESUMEN

Amyloid ß-peptide (Aß) has been implicated as a key molecule in the neurodegenerative cascades of Alzheimer's disease (AD). Humanin (HN) is a secretory peptide that inhibits the neurotoxicity of Aß. However, the mechanism(s) by which HN exerts its neuroprotection against Aß-induced AD-like pathological changes and memory deficits are yet to be completely defined. In the present study, we provided evidence that treatment of rats with HN increases the number of dendritic branches and the density of dendritic spines, and upregulates pre- and post-synaptic protein levels; these effects lead to enhanced long-term potentiation and amelioration of the memory deficits induced by Aß(1-42). HN also attenuated Aß(1-42)-induced tau hyperphosphorylation, apparently by inhibiting the phosphorylation of Tyr307 on the inhibitory protein phosphatase-2A (PP2A) catalytic subunit and thereby activating PP2A. HN also inhibited apoptosis and reduced the oxidative stress induced by Aß(1-42). These findings provide novel mechanisms of action for the ability of HN to protect against Aß(1-42)-induced AD-like pathological changes and memory deficits.


Asunto(s)
Enfermedad de Alzheimer/tratamiento farmacológico , Encéfalo/efectos de los fármacos , Trastornos del Conocimiento/tratamiento farmacológico , Dendritas/efectos de los fármacos , Péptidos y Proteínas de Señalización Intracelular/uso terapéutico , Aprendizaje por Laberinto/efectos de los fármacos , Enfermedad de Alzheimer/inducido químicamente , Enfermedad de Alzheimer/patología , Péptidos beta-Amiloides , Animales , Encéfalo/patología , Cognición/efectos de los fármacos , Trastornos del Conocimiento/patología , Trastornos del Conocimiento/psicología , Dendritas/patología , Espinas Dendríticas/efectos de los fármacos , Espinas Dendríticas/patología , Modelos Animales de Enfermedad , Hipocampo/efectos de los fármacos , Hipocampo/patología , Péptidos y Proteínas de Señalización Intracelular/farmacología , Masculino , Neuronas/efectos de los fármacos , Neuronas/patología , Estrés Oxidativo/efectos de los fármacos , Fosforilación/efectos de los fármacos , Ratas , Ratas Wistar
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