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Nodular fasciitis (NF) is a benign and self-limiting fibroblastic proliferation that originates from the superficial fascia and extends into the subcutaneous tissue or muscle. It typically manifests in individuals aged 20 to 35 years, with rare occurrences observed in patients over the age of 60 years. We herein report a case involving a 75-year-old man with NF in the right vocal cord. The patient sought medical attention at the Department of Otolaryngology of our hospital because of a 1-month history of hoarseness and breathlessness. The diagnosis was unable to be confirmed through preoperative pathological examination. After admission to our hospital, various examinations were completed and surgical treatment was performed, and the postoperative histopathological findings revealed the presence of NF in the right vocal cord. NF of the vocal cord is a rare clinical entity. Given its rapid progression and propensity for marked infiltration, it often poses diagnostic challenges because it can mimic various malignant soft tissue tumors. Therefore, thorough exclusion of other neoplastic lesions is imperative prior to confirming the diagnosis of NF through pathological examination. Local surgical resection remains the primary treatment modality.
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Fascitis , Humanos , Masculino , Fascitis/diagnóstico , Fascitis/cirugía , Fascitis/patología , Anciano , Pliegues Vocales/patología , Pliegues Vocales/cirugía , Ronquera/etiología , Ronquera/diagnóstico , Diagnóstico DiferencialRESUMEN
Attempts have been made to extract nickel from ores and nickel-containing wastes using the chlorination method. However, the use of gaseous chlorinating agents is limited due to their toxicity. High-temperature chlorination of nickel oxide using calcium chloride is analyzed in this study. The volatilization percentage is positively correlated to temperature and CaCl2 dosage and negatively correlated to oxygen partial pressure. The apparent activation energy is calculated to be 142.91 kJ/mol, between 1173 K and 1323 K, which suggests that the high-temperature chlorination of nickel oxide using calcium chloride is controlled by a chemical reaction.
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Gold is a valued, critical element whose chemical activation or extraction is challenging. Non-cyanide extraction of gold is now the focus, and N-bromosuccinimide(NBS) is attracting attention. Herein, new insights into the possible mechanism are deeply revealed through comprehensive analysis and detection of the reaction by using elementary gold and gold bearing ore. Experiments on gold foil indicate that Au can be activated in NBS solution to perform a satisfactory dissolution. Application of NBS in gold extraction from ore show a high yield of 86.24% under optimal conditions of NBS dosage 0.05 M, liquid-solid ratio 4:1, stirring speed 400 rpm, pH 8, 25 °C and leaching for 20 h, while yields of other coexisting metals are nearly negligible. The process leads to direct, efficient, one-pot conversion of gold, into simple water-soluble salts. Characterizations show that the framework of NBS are not destroyed, only bromine separates from the framework. The oxidation of neutral gold atom to trivalent Au(III) occurs in a mild, clean and room-temperature chemistry, which converts gold to [AuBr4]-, and the framework to succinimide. The active bromine and radical Br (Brâ¢) generated from in-situ autocatalysis of NBS are responsible for this. The systematic results herald a green procedure for preparation of gold derivatives and gold extraction industry.
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A series of superhydrophobic polycarbonate porous monoliths modified with metal organic framework (Z8/PC) were firstly fabricated through a facile thermally impacted non-solvent induced phase separation method for efficient selective oil/water separation. The performance of the monoliths on oil/water separation was evaluated in terms of selectivity, equilibrium adsorption capacity, corrosion resistance, kinetics, and circulation. The results showed that the use of ZIF-8 significantly compensated for the shortage of pure monolith. Compared with pure PC monolith, the hydrophobic angle of the Z8/PC-2 monolith promoted from 136.18° to 154.25° due to the micro-nano flower surface. Meanwhile, the Z8/PC-2 monolith displayed a more intricate and continuous interconnected 3D hierarchical micro-nano structure, which possessed the monolith a higher specific surface area of 146.84 m2 g-1 and porosity of 89.5%. What's more, more superior oil/water separation abilities of Z8/PC-2 monolith were manifested by the selective removal of oil or organic solvent from water within 30s, high equilibrium adsorption capacity, and excellent corrosion resistance. In addition, the ten-cycle regeneration of porous monoliths via centrifugation or evaporation displayed additional attractiveness. Therefore, porous Z8/PC monolith will be a promising candidate for the efficient selective oil/water separation of oil spills and organic solvents.
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Estructuras Metalorgánicas/química , Nanoestructuras/química , Contaminación por Petróleo/análisis , Cemento de Policarboxilato/química , Aguas Residuales/química , Contaminantes Químicos del Agua/análisis , Zinc/química , Adsorción , Interacciones Hidrofóbicas e Hidrofílicas , Modelos Teóricos , PorosidadRESUMEN
Compared with As(V), As(III) is a tricky issue worldwide for its higher toxicity and more difficult to remove in aqueous solution. In present study, a novel CeOx/MnOy nanoparticles anchored layered structural TiO2 pillared montmorillonite (TiO2-Mt-Ce-Mn) was fabricated and applied as an efficient absorbent for As(III) removal. Under the condition of the initial As(III) concentration = 20 mg/L and adsorbent dose = 0.4 g/L, TiO2-Mt-Ce-Mn with a high specific surface area (148.099 m2/g) has an outstanding adsorption capacity (46.58 mg/g) for As(III) at pH 4.2, and the effect of oxy-anions on adsorption efficiency is slight except for H2PO4-. Interestingly, the layered structure provides sufficient attachment space for CeOx/MnOy nanoparticles, while CeOx/MnOy nanoparticles in turn endows TiO2-Mt a high redox potential, which further facilitates the oxidation of As(III), and this significantly reduces the toxicity of wastewater. The adsorption mechanism includes the oxidation of As(III) to As(V) by both CeOx/MnOy nanoparticles and TiO2 and effective adsorption of the residual As(III) and the formed As(V) subsequently. In addition, the adsorption efficiency of TiO2-Mt-Ce-Mn can still maintain 79.6% after five cycles through a facile regeneration method. Thus, the nanocomposite with low-cost synthesis process, high adsorption capacity, and regenerability is a promising candidate for As(III) treatment of wastewater.
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Arsénico , Nanopartículas , Contaminantes Químicos del Agua/análisis , Purificación del Agua , Adsorción , Bentonita , Titanio , Aguas ResidualesRESUMEN
Large amounts of cyanide tailings are produced during the cyanidation process in gold extraction, which are hazardous solid wastes due to the toxic cyanide. Pyrite is one of the main minerals in cyanide tailings. The removal of cyanide adsorbed on pyrite by H2O2 oxidation under alkaline conditions was investigated in this study. It was found that the removal efficiency was positively correlated with pH from 5 to 12, but remained almost constant when pH was higher than 12. The highest cyanide removal efficiency of 91.10% was achieved by adding no less than 0.6â¯wt.% of H2O2. Cyanide removal was positively correlated with the CN- adsorption amount between 1.06 and 8.5â¯mg/g, and temperature between 25 and 85°C. The removal of cyanide adsorbed on pyrite by H2O2 oxidation under alkaline conditions was due to the oxidation of pyrite. Hexacyanoferrate, thiocyanate and sulfate were generated with mole ratios of about 2.03:1.12:3.17 during the cyanide removal.
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Cianuros/química , Peróxido de Hidrógeno/química , Hierro/química , Modelos Químicos , Sulfuros/química , Adsorción , Concentración de Iones de Hidrógeno , Oxidación-ReducciónRESUMEN
The alkaline leaching solution from arsenic-containing gold concentrate contains a large amount of arsenate ions, which should be removed because it is harmful to the production process and to the environment. In this study, conventional Fe (III) precipitation was used to remove arsenic from the leaching solution. The precipitation reaction was carried out at the normal temperature, and the effects of pH value and Fe/As ratio on the arsenic removal were investigated. The results show that the removal rate of arsenic is distinctive at different pH values, and the effect is best within the pH range of 5.25-5.96. The removal rate can be further increased by increasing the ratio of Fe/As. When the pH = 5.25-5.96 and Fe/As > 1.8, the arsenic in the solution can be reduced to below 5â mg/L. However, the crystallinity of ferric arsenate is poor, and the particle size is small, most of which is about 1â µm. The leaching toxicity test shows the leaching toxicity of precipitates gradually decreased by the increase of Fe/As. The precipitates can be stored safely as the ratio of Fe/As exceeded 2.5.
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Arsénico , Contaminantes Químicos del Agua , Precipitación Química , Compuestos Férricos , Concentración de Iones de Hidrógeno , HierroRESUMEN
In this work, 20(S)-protopanaxadiol (PPD)-loaded polycaprolactone (PCL) nanofibres were successfully fabricated by the electrospinning technique using Tween 80 as a solubilizer. Firstly, smooth and continuous nanofibres were collected using suitable solvents and appropriate spinning conditions. Secondly, nanofibre mats were characterized by scanning electron microscopy, thermogravimetric (TG) analysis, Fourier transform infrared spectroscopy and mechanical testing. Finally, nanofibrous membranes were evaluated using water contact angle, in vitro drug release, biodegradation test, in vitro and in vivo anti-tumour activity and cell apoptosis assay. Scanning electron microscopic observations indicated that the diameter of the drug-loaded nanofibres increased with the increase of drug concentration. TG analysis and mechanical test showed that nanofibres were equipped with great thermal and mechanical properties. Biodegradation test exhibited that the structure of fabricated nanofibres had a certain degree of change after 15 days. An in vitro release study showed that PPD from drug-loaded nanofibres could be released in a sustained and prolonged mode. The cytotoxic effect of drug-loaded nanofibre mats examined on human laryngeal carcinoma cells (Hep-2 cells) demonstrated that the prepared nanofibres had a remarkable anti-tumour effect. Meanwhile, the drug-loaded fibre mats showed a super anti-tumour effect in an in vivo anti-tumour study. All in all, PCL nanofibres could be a potential carrier of PPD for cancer treatment.
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The discharge of heavy metal ions such as Cu2+ and Pb2+ poses a severe threat to public health and the environment owing to their extreme toxicity and bioaccumulation through food chains. Herein, we report a novel organic-inorganic hybrid adsorbent, Al(OH)3-poly(acrylamide-dimethyldiallylammonium chloride)-graft-dithiocarbamate (APD), for rapid and effective removal of Cu2+ and Pb2+. In this adsorbent, the "star-like" structure of Al(OH)3-poly(acrylamide-dimethyldiallylammonium chloride) served as the support of dithiocarbamate (DTC) functional groups for easy access of heavy metal ions and assisted development of large and compact floccules. The synthesized adsorbent was characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), and thermogravimetric analysis (TGA). APD was demonstrated to have rapid adsorption kinetics with an initial rate of 267.379 and 2569.373mg/(g·min) as well as superior adsorption capacities of 317.777 and 586.699mg/g for Cu2+ and Pb2+ respectively. The adsorption process was spontaneous and endothermic, involving intraparticle diffusion and chemical interaction between heavy metal ions and the functional groups of APD. To assess its versatility and wide applicability, APD was also used in turbid heavy metal wastewater, and performed well in removing suspended particles and heavy metal ions simultaneously through flocculation and chelation. The rapid, convenient and effective adsorption of Cu2+ and Pb2+ gives APD great potential for heavy metal decontamination in industrial applications.
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Quelantes/química , Cobre/química , Plomo/química , Contaminantes Químicos del Agua/química , Adsorción , Cobre/análisis , Restauración y Remediación Ambiental/métodos , Plomo/análisis , Eliminación de Residuos Líquidos/métodosRESUMEN
An inorganic-organic hybrid flocculant Al(OH)3-polyacrylamide (Al-PAM) with narrow molecular weight distribution was synthesized using inverse microemulsion polymerization. The hybrid polymer Al-PAM was characterized by Infrared spectroscopy, thermogravimetric analysis, transmission electron microscopy and scanning electron microscopy, and it was found that it had a 'star-like' structure in which Al(OH)3 colloidal particles acted as cores linking PAM chains. The properties of Al-PAM were investigated in flocculating 10 wt% cyanide tailing suspensions. It was found that as the amount of Al-PAMM1 with high molecular weight and aluminum content increased, the initial settling rate of particles accelerated, achieving the maximum 6.6 m/h, 17.3 times the rate of the control without flocculants. The turbidity of the supernatant decreased to 35 ± 2 NTU accordingly, compared to 353 ± 2 NTU of that in the control, which meant that 90.0% of turbidity was removed from the cyanide tailing suspensions. The flocculation mechanism was further explored by floccule size and ζ potential measurements. The superior performance of cationic Al-PAM in flocculating negatively charged particles compared to commercial non-ionic GG indicated that electrostatic repulsion between tailing particles was a crucial factor in deciding the flocculation performance of the polymer. The study demonstrated that both charge neutralization and bridge adsorption were conductive to the particle flocculation.
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Resinas Acrílicas/química , Cianuros/química , Polímeros/química , Adsorción , Hidróxido de Aluminio/química , Floculación , Peso Molecular , Polimerizacion , Suspensiones/químicaRESUMEN
With the continuous rapid urbanization process over the last three decades, outdoors air pollution has become a progressively more serious public health hazard in China. To investigate the possible associations, lag effects and seasonal differences of urban air quality on respiratory health (allergic rhinitis) in Changchun, a city in Northeastern China, we carried out a time-series analysis of the incidents of allergic rhinitis (AR) from 2013 to 2015. Environmental monitoring showed that PM2.5 and PM10 were the major air pollutants in Changchun, followed by SO2, NO2 and O3. The results also demonstrated that the daily concentrations of air pollutants had obvious seasonal differences. PM10 had higher daily mean concentrations in spring (May, dust storms), autumn (October, straw burning) and winter (November to April, coal burning). The mean daily number of outpatient AR visits in the warm season was higher than in the cold season. The prevalence of allergic rhinitis was significantly associated with PM2.5, PM10, SO2 and NO2, and the increased mobility was 10.2% (95% CI, 5.5%-15.1%), 4.9% (95% CI, 0.8%-9.2%), 8.5% (95% CI, -1.8%-19.8%) and 11.1% (95% CI, 5.8%-16.5%) for exposure to each 1-Standard Deviation (1-SD) increase of pollutant, respectively. Weakly or no significant associations were observed for CO and O3. As for lag effects, the highest Relative Risks (RRs) of AR from SO2, NO2, PM10 and PM2.5 were on the same day, and the highest RR from CO was on day 4 (L4). The results also indicated that the concentration of air pollutants might contribute to the development of AR. To summarize, this study provides further evidence of the significant association between ambient particulate pollutants (PM2.5 and PM10, which are usually present in high concentrations) and the prevalence of respiratory effects (allergic rhinitis) in the city of Changchun, located in Northeastern China. Environmental control and public health strategies should be enforced to address this increasingly challenging problem.
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Contaminantes Atmosféricos/efectos adversos , Contaminación del Aire/efectos adversos , Rinitis Alérgica/etiología , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Contaminantes Atmosféricos/análisis , Contaminación del Aire/análisis , Niño , Preescolar , China/epidemiología , Monitoreo del Ambiente , Femenino , Humanos , Incidencia , Lactante , Masculino , Persona de Mediana Edad , Prevalencia , Salud Pública , Rinitis Alérgica/epidemiología , Estaciones del Año , Factores de Tiempo , Urbanización , Adulto JovenRESUMEN
Knowledge of the relevant selection rules is crucial for the accurate interpretation of experimental spectra in general. There has been a consensus for a long time that the incoherent inelastic neutron scattering (INS) spectroscopy of the vibrations of discrete molecular compunds is free from any selection rules. We contradict this widely held view by presenting an analytical derivation of the general selection rule for the INS spectroscopy of a hydrogen molecule inside a near-spherical nanocavity. It defines all forbidden transitions, originating in a range of initial translation-rotation (TR) states, ground and excited, of the caged para- and ortho-H2, as well as HD, that are unobservable in the INS spectra. These predictions are amenable to experimental verification. In addition, we demonstrate that the general selection rule applies to the INS spectroscopy of any diatomic molecule in a nanocavity with near-spherical symmetry, which exhibits strong TR coupling. Its existence strongly suggests that similar selection rules apply to the INS spectra of other molecular and supramolecular systems, and need to be identified.
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We report an inelastic neutron scattering (INS) study of a H2 molecule encapsulated inside the fullerene C60 which confirms the recently predicted selection rule, the first to be established for the INS spectroscopy of aperiodic, discrete molecular compounds. Several transitions from the ground state of para-H2 to certain excited translation-rotation states, forbidden according to the selection rule, are systematically absent from the INS spectra, thus validating the selection rule with a high degree of confidence. Its confirmation sets a precedent, as it runs counter to the widely held view that the INS spectroscopy of molecular compounds is not subject to any selection rules.
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We report rigorous quantum calculations of the inelastic neutron scattering (INS) spectra of HD@C60, over a range of temperatures from 0 to 240 K and for two incident neutron wavelengths used in recent experimental investigations. The computations were performed using our newly developed methodology, which incorporates the coupled five-dimensional translation-rotation (T-R) eigenstates of the guest molecule as the initial and final states of the INS transitions, and yields highly detailed spectra. Depending on the incident neutron wavelength, the number of computed INS transitions varies from almost 500 to over 2000. The low-temperature INS spectra display the fingerprints of the coupling between the translational and rotational motions of the entrapped HD molecule, which is responsible for the characteristic splitting patterns of the T-R energy levels. INS transitions from the ground T-R state of HD to certain sublevels of excited T-R multiplets have zero intensity and are absent from the spectra. This surprising finding is explained by the new INS selection rule introduced here. The calculated spectra exhibit strong temperature dependence. As the temperature increases, numerous new peaks appear, arising from the transitions originating in excited T-R states which become populated. Our calculations show that the higher temperature features typically comprise two or more transitions close in energy and with similar intensities, interspersed with numerous other transitions whose intensities are negligible. This implies that accurately calculated energies and intensities of INS transitions which our methodology provides will be indispensable for reliable interpretation and assignment of the experimental spectra of HD@C60 and related systems at higher temperatures.
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Hydrogen is one of the few molecules that has been incarcerated in the molecular cage of C60 to form the endohedral supramolecular complex H2@C60. In this confinement, hydrogen acquires new properties. Its translation motion, within the C60 cavity, becomes quantized, is correlated with its rotation and breaks inversion symmetry that induces infrared (IR) activity of H2. We apply IR spectroscopy to study the dynamics of hydrogen isotopologues H2, D2 and HD incarcerated in C60. The translation and rotation modes appear as side bands to the hydrogen vibration mode in the mid-IR part of the absorption spectrum. Because of the large mass difference of hydrogen and C60 and the high symmetry of C60 the problem is almost identical to a vibrating rotor moving in a three-dimensional spherical potential. We derive potential, rotation, vibration and dipole moment parameters from the analysis of the IR absorption spectra. Our results were used to derive the parameters of a pairwise additive five-dimensional potential energy surface for H2@C60. The same parameters were used to predict H2 energies inside C70. We compare the predicted energies and the low-temperature IR absorption spectra of H2@C70.
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In the supramolecular complex H2@C60, the lightest of molecules, H2, is encapsulated inside the most highly symmetric molecule C60. The elegance and apparent simplicity of H2@C60 conceal highly intricate quantum dynamics of the coupled translational and rotational motions of the guest molecule in a nearly spherical nanoscale cavity, which embodies some of the most fundamental concepts of quantum mechanics. Here we present the first rigorous and highly accurate quantum calculations of the inelastic neutron scattering (INS) spectra of this prototypical endohedral fullerene complex and their temperature dependence. The calculations enable complete assignment of the recently reported experimental INS spectra of H2@C60 measured at several temperatures. We also derive a new and unexpected selection rule for the INS spectroscopy of H2 in a near-spherical confinement, which explains why the INS transitions between certain translation-rotation eigenstates of H2 in C60 have zero intensity and do not appear in the spectra.
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We report rigorous quantum five-dimensional (5D) calculations of the coupled translation-rotation (TR) energy levels and wave functions of an H2 molecule, in the ground (ν = 0) and vibrationally excited (ν = 1) states, confined inside the octahedral interstitial site of solid C60 with S6 symmetry. Translational and rotational excitations of H2 in this nanocavity have been measured by the inelastic neutron scattering (INS) and infrared (IR) spectroscopy, enabling direct comparison between theory and experiment. A pairwise additive 5D intermolecular potential energy surface (PES) was employed in the calculations. The quantum calculations cover the range of energies and types of translational and rotational excitations of the guest molecule which go substantially beyond those considered in the earlier theoretical investigations of this system, revealing new information about the TR energy level structure. The computed j = 1 and j = 2 rotational levels and their splittings, as well as the translational fundamental, are in semi-quantitative agreement with the available INS and IR data, indicating the need for a more accurate intermolecular PES. Our calculations reveal a strong dependence of the TR energy levels, in particular their splittings, on the setting angle which defines the orientation of the C60 molecules relative to their local threefold axes.
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Fulerenos/química , Hidrógeno/química , Teoría Cuántica , RotaciónRESUMEN
Marine ecosystem is a complex nonlinear system. However, ecosystem health assessment conventionally builds on a linear superposition of changes in ecosystem components and probably fails to evaluate nonlinear interactions among various components. To better reflect the intrinsic interactions and their impacts on ecosystem health, an ecosystem coordination index, defined as the matching level of ecosystem structure/services, is proposed and incorporated into the ecosystem health index for a systematic diagnosis in the Pearl River Estuary, China. The analysis results show that the ecosystem health index over the last three decades decreased from 0.91 to 0.50, indicating deteriorating from healthy to unhealthy status. The health index is 3-16% lower than that calculated using the common method without considering ecosystem coordination. Ecosystem health degradation in the Pearl River Estuary manifested as significant decreases in structure/services and somewhat mismatching among them. Overall, the introduction of coordination in ecosystem health assessment could improve the understanding of the mechanism of marine ecosystem change and facilitate effective restoration of ecosystem health.
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Ecosistema , Monitoreo del Ambiente/métodos , Contaminantes del Agua , China , Estuarios , Modelos Teóricos , RíosRESUMEN
Based on the "pressure-state-response (PSR)" concept model, a degradation evaluation index system was constructed for the cropland, wetland, and inshore ecosystems in Dongtan coastal zone of Chongming. By using multiplication synthesis, a combination of analytic hierarchy process and entropy weight method, the weights of each evaluation index were obtained, and, through geographical space index quantification and spatial clustering, the degradation degree of each ecological system was analyzed. The results showed that the degradation degree of Dongtan coastal ecosystems in 2005 could be spatially classified into four classes, i.e., class I, class II, class III and class IV, with the degradation degree aggravated increasingly. For the cropland, wetland, and inshore ecosystems, the weight of heavy metals was the largest, being 0.65, 0.20, and 0.26, respectively. Bird diversity index, land use degree, and Spartina alterniflora coverage also had greater effects on wetland ecosystem, and their weights were 0.26, 0.16, and 0.10, respectively. For cropland ecosystem, land use degree was also an important affecting factor, with the weight of 0.22.
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Conservación de los Recursos Naturales/estadística & datos numéricos , Ecosistema , Monitoreo del Ambiente/métodos , Humedales , China , Océanos y MaresRESUMEN
We report rigorous quantum five-dimensional (5D) calculations of the translation-rotation (T-R) energy levels and wave functions of H(2) inside aza-thia-open-cage fullerene (ATOCF). Translational and rotational excitations of this endohedral complex have been measured in a recent inelastic neutron scattering (INS) study, enabling direct comparison between theory and experiment. ATOCF has no symmetry, and therefore the intermolecular potential energy surface (PES) governing the T-R dynamics of H(2) is strongly anisotropic. A pairwise additive PES is employed in the calculations. Inspection of the wave functions shows three regular quasi-1D translational modes aligned with the Cartesian x, y, and z axes, respectively. These and other translational excitations can be assigned with the Cartesian quantum numbers v(x), v(y), and v(z). The radial anisotropy of the cage environment causes the splitting of the translational fundamental into three excitations whose frequencies differ substantially; the z mode directed toward the ATOCF orifice has the lowest frequency and is the most anharmonic. All three translational modes exhibit negative anharmonicity. The j = 1 rotational level of H(2) is also split into a triplet, due to the angular anisotropy of the cage. The complete lifting of the degeneracies of the translational fundamental and the j = 1 triplet of the encapsulated H(2) molecule that emerges from the calculations is also observed in the INS spectra of H(2)@ATOCF. The calculated magnitudes of both splittings, as well as the energies of the individual sublevels, rotational and translational, are in good agreement with the INS data.