冰期间冰期转换过程中陆地碳库的演化规律研究

Terrestrial carbon pool mainly consists of three parts: the active carbon pool of the vegetation，soil carbon pools and the lithosphere carbon pool of less activity. Under natural conditions，vegetation carbon pools，soil carbon exchange with atmospheric carbon pool directly，the lithosphere participate in the global carbon cycle by weathering Our research have coverd the soil organic carbon density，plant biomass (carbon density)，plant net primary productivity of past 40 ka，and the magnetic susceptibility，grain size，weathering of silicate carbon consumption of past 140 ka. This study has achieved a number of conclusions as shown below. 1 Silicate weathering CO2 consumption in the long-term fluctuations with a similar deep-sea δ18O record，demonstate that it not only can be used as one of the instructions of terrestrial carbon pool，even can be used as indicators of global environmental change; silicate weathering CO2 consumption and susceptibility shown a clear relationship between lag or lead at different times，it maybe lies on how the climate change. 2 Soil carbon pools in line with the global climate on long-term，but the relationship between soil carbon density and climate change was not obvious in short-term change，generally lags behind the changes in other climatic proxies. 3 Carbon density of vegetation and other proxy indicators of climate have good consistency. In the study period，perform the cycle of glacial and interglacial completely，but because of the ancient vegetation of accurate information is difficult to obtain，it did not reflect rapid response to climate change. 4 Cooling events is conducive to soil organic carbon accumulation but not conducive to weathering and vegetation growth. High temperature environment is not conducive to the accumulation of soil organic carbon. 5 In the deglacial time from the last glacial maximum to the Holocene，weathering carbon consumption seems earlier than vegetation and soil organic carbon in the fluctuant increase.Does it imply that the effects of silicate weathering is an important factor to the global carbon cycle and global climate change? It is worth further research.

Complete hydrodechlorination of chlorobenzene and its derivatives over supported nickel catalysts under liquid phase conditions

Liquid phase hydrodechlorination of chlorobenzene was studied over Ni/active carbon (Ni/AC), Ni/gamma-Al2O3, Ni/SiO2 and Raney Ni. The complete hydrodechlorination of chlorobenzene was realized at 333-343 K on Ni/AC under hydrogen atmosphere of 1.0 MPa in the presence of alkaline hydroxide. Aryl halides, three chlorotoluenes (o-, m- and p-), three chloroanilines, three chlorobenzotrifluorides, three dichlorobenzenes and two trichlorobenzenes (1,2,3- and 1,2,4-) were also completely hydrodechlorinated under the similar conditions. Chlorobenzene derivatives having either an electron-donating group or an electron-withdrawing group decreased their reactivities with respect to the unsubstituted chlorobenzene.

Development of electrocatalysts for direct alcohol fuel cells

In the present review, we summarize the recent progress in electrocatalysts for direct alcohol fuel cells, focussing on the research of electrocatalysts for both alcohol oxidation and oxygen reduction, which are crucial in the development of fuel cells. A modified EG (ethylene polyol) method to prepare well-dispersed nano-sized Pt-based electrocatalysts with high loadings is reported. By this method, a more active carbon supported PtRu catalyst for methanol oxidation reaction and a PtSn catalyst for ethanol oxidation reaction have been synthesized successfully. Furthermore, a methanol tolerant Pd-based catalyst for cathode oxygen reduction reaction has been developed. HRTEM and HR-EDS have been employed to characterize the microstructure and micro-components of the above electrocatalysts. Results show that the bimetallic electrocatalysts prepared by the modified EG method display uniform size and homogeneous components at nanometer scale.

Adsorption of metal ions on nitrogen surface functional groups in activated carbons

A commercially available coconut-shell-derived active carbon was oxidized with nitric acid, and both the original and oxidized active carbons were treated with ammonia at 1073 K to incorporate nitrogen functional groups into the carbon. An active carbon with very high nitrogen content (similar to9.4 wt % daf) was also prepared from a nitrogen-rich precursor, polyacrylonitrile (PAN). These nitrogen-rich carbons had points of zero charge (pH(pzc)) similar to H-type active carbons. X-ray absorption near-edge structure (XANES) spectroscopy, Fourier transform infrared (FTIR) spectroscopy, and temperature-programmed desorption (TPD) were used to characterize the nitrogen functional groups in the carbons. The nitrogen functional groups present on the carbon surface were pyridinic, pyrrolic (or indolic), and pyridonic structures. The adsorption of transition metal cations Cd2+, Ni2+, and Cu2+ from aqueous solution on the suite of active carbons showed that adsorption was markedly higher for carbons with nitrogen functional groups present on the surface than for carbons with similar pH(pzc) values. In contrast, the adsorption characteristics of Ca2+ from aqueous solution were similar for all the carbons studied. Flow microcalorimetry (FMC) studies showed that the enthalpies of adsorption of Cd2+(aq) on the active carbons with high nitrogen contents were much higher than for nitric acid oxidized carbons studied previously, which also had enhanced adsorption characteristics for metal ion species. The enthalpies of adsorption of Cu2+ were similar to those obtained for Cd2+ for specific active carbons. The nitrogen functional groups in the carbons act as surface coordination sites for the adsorption of transition metal ions from aqueous solution. The adsorption characteristics of these carbons are compared with those of oxidized carbons.

Major grass pollen allergen Lol p 1 binds to diesel exhaust particles : implications for asthma and air pollution

Background Grass pollen allergens are known to be present in the atmosphere in a range of particle sizes from whole pollen grains (approx. 20 to 55 μim in diameter) to smaller size fractions < 2.5 μ (fine particles, PM2.5). These latter particles are within the respirable range and include allergen-containing starch granules released from within the grains into the atmosphere when grass pollen ruptures in rainfall and are associated with epidemics of thunderstorm asthma during the grass pollen season. The question arises whether grass pollen allergens can interact with other sources of fine particles, particularly those present during episodes of air pollution.

Objective We propose the hypothesis that free grass pollen allergen molecules, derived from dead or burst grains and dispersed in microdroplets of water in aerosols, can bind to fine particles in polluted air.

Methods We used diesel exhaust carbon particles (DECP) derived from the exhaust of a stationary diesel engine, natural highly purified Lol p 1, immunogold labelling with specific monoclonal antibodies and a high voltage transmission electron -microscopic imaging technique

Results DECP are visualized as small carbon spheres, each 30–60 nm in diameter, forming fractal aggregates about 1–2μ in diameter. Here we test our hypothesis and show by in vitro experiments that the major grass pollen allergen, Lol p I. binds to one defined class of fine particles, DECP.

Conclusion DECP are in the respirable size range, can bind to the major grass pollen allergen Lol p I under in vitro conditions and represent a possible mechanism by which allergens can become concentrated in polluted air and thus trigger attacks of asthma.

Utilização de microemulsões como agentes modificadores de superfícies para remoção de íons metálicos

The heavy metals are used in many industrial processes and when discharged to the environment can cause harmful effects to human, plants and animals. The adsorption technology has been used as an effective methodology to remove metallic ions. The search for new adsorbents motivated the development of this research, accomplished with the purpose of removing Cr (III) from aqueous solutions. Diatomite, chitosan, Filtrol 24TM and active carbon were used as adsorbents. To modify the adsorbent surface was used a bicontinuous microemulsion composed by water (25%), kerosene (25%), saponified coconut oil (10%) and as co-surfactant isoamyl or butyl alcohols (40%). With the objective of developing the best operational conditions the research started with the surfactant synthesis and after that the pseudo-ternary diagrams were plotted. It was decided to use the system composed with isoamyl alcohol as co-surfactant due its smallest solubility in water. The methodology to impregnate the microemulsion on the adsorbents was developed and to prepare each sample was used 10 g of adsorbent and 20 mL of microemulsion. The effect of drying time and temperature was evaluated and the best results were obtained with T = 65 ºC and t = 48 h. After evaluating the efficiency of the tested adsorbents it was decided to use chitosan and diatomite. The influence of the agitation speed, granule size, heavy metal synthetic solution concentration, pH, contact time between adsorbent and metal solution, presence or not of NaCl and others metallic ions in the solution (copper and nickel) were evaluated. The adsorption isotherms were obtained and Freundlich and Langmuir models were tested. The last one correlated better the data. With the purpose to evaluate if using a surfactant solution would supply similar results, the adsorbent surface was modified with this solution. It was verified that the adsorbent impregnated with a microemulsion was more effective than the one with a surfactant solution, showing that the organic phase (kerosene) was important in the heavy metal removal process. It was studied the desorption process and verified that the concentrated minerals acids removed the chromium from the adsorbent surface better than others tested solutions. The treatment showed to be effective, being obtained an increase of approximately 10% in the chitosan s adsorption capacity (132 mg of Cr3+ / g adsorbent), that was already quite efficient, and for diatomite, that was not capable to remove the metal without the microemulsion treatment, it was obtained a capacity of 10 mg of Cr3+ / g adsorbent, checking the applied treatment effectiveness

O impacto da extensão universitária sobre a formação acadêmica em Odontologia

This qualitative study of descriptive and exploratory nature was conducted with the aim of evaluating the contribution of university extension towards the training and life histories of dentistry students, using the focus group technique. The material was assessed using the collective subject discourse analysis technique. The results showed the impact exerted by academic experience, in extension activities within the personal, professional and active citizenship spheres. The subjects' perceptions revealed an opportunity to develop and improve their professional skills, through recognition of distinct realities of life, through breaking away from the traditional model of teaching and through fruitful relationships between students, university and society. Feelings of satisfaction, personal fulfillment, recognition and being an active and critical citizen were reported. It was concluded that experience within the field of extension is an important agent for the individual and collective process of academic training.

Migración y ecología trófica de peces migradores verticales dominantes del Atlántico nordeste subtropical: implicaciones en el flujo activo de carbono

[EN]Diel vertical migrants (DVMs) are mainly zooplankton and micronekton that migrate upward from 400-700 m depth every night to feed in the productive epipelagic zone and come back at dawn to the mesopelagic zone, where they release the ingested carbon. DVMs should contribute to the biological pump in the ocean and, accordingly, to thevglobal CO2 balance. A large portion of the DVMs biomass are the lanternfishes (myctophidae), which might represent a pathway accounting for a substantial export of organic carbon to the deep ocean. Nevertheless, the magnitude of this transport is still poorly known. The combined study of migration and feeding ecology is a good approach to improve our knowledge of the DVMs role in this active carbon flux. Two dominant myctophids in the Subtropical Eastern North Atlantic Ocean (Hygophum hygomii (Lütken, 1892) and (Lobianchia dofleini (Zugmayer, 1911)) were studied from several surveys carried out around the Canary Islands during the last decade. Our results showed a marked diel vertical migration and a prevailing nocturnal feeding with predation mainly on copepods and euphausiids. The digestion state of prey suggested a slow stomach evacuation rate and that most of the ingested carbon in the epipelagic is efficiently transported to the mesopelagic zone.

Zooplankton, micronekton and biological pump: Beyond the mesopelagic zone

[EN] Migrant biota transports carbon to the mesopelagic zone due to their feeding at the shallower layers and their defecation, respiration, excretion and mortality at depth. The so-called active flux has been considered a small number compared to gravitational sinking. Recent assessments in subtropical waters show an important effect due to predation by interzonal diel vertical migrants (DVMs). The consumption and subsequent transport of epipelagic zooplankton by DVMs (mainly micronekton) to the mesopelagic zone seemed similar to the mean gravitational export. However, the consequences of this active transport to the bathypelagic zone are almost unknown. Here, we show the effect of the Atlantic and Pacific equatorial upwelling systems on the vertical distribution of acoustic backscatter from the surface to bathypelagic depths. The enhancement of the acoustic signal below the upwelling zone was observed to reach 4000 m depth, coinciding with high abundances and activity of bacteria at those depths. The results suggest an active carbon transport from the epipelagic driven by zooplankton and micronekton, enhancing the efficiency of the biological pump and giving an insight about the fate of an increased productivity at the shallower layers of the ocean

Characterization and performance of carbonaceous materials obtained from exhausted sludges for the anaerobic biodecolorization of the azo dye Acid Orange II.

This work presents the preliminary study of new carbonaceous materials (CMs) obtained from exhausted sludge, their use in the heterogeneous anaerobic process of biodecolorization of azo dyes and the comparison of their performance with one commercial active carbon. The preparation of carbonaceous materials was conducted through chemical activation and carbonization. Chemical activation was carried out through impregnation of sludge-exhausted materials with ZnCl2 and the activation by means of carbonization at different temperatures (400, 600 and 800°C). Their physicochemical and surface characteristics were also investigated. Sludge based carbonaceous (SBC) materials SBC400, SBC600 and SBC800 present values of 13.0, 111.3 and 202.0m(2)/g of surface area. Biodecolorization levels of 76% were achieved for SBC600 and 86% for SBC800 at space time (τ) of 1.0min, similar to that obtained with commercial activated carbons in the continuous anaerobic up-flow packed bed reactor (UPBR). The experimental data fit well to the first order kinetic model and equilibrium data are well represented by the Langmuir isotherm model. Carbonaceous materials show high level of biodecolorization even at very short space times. Results indicate that carbonaceous materials prepared from sludge-exhausted materials have outstanding textural properties and significant degradation capacity for treating textile effluents.

Dissolved organic matter molecular composition and concentrations from a large scale mesocosm study KOSMOS 2013 Kristineberg) on ocean acidification

Marine dissolved organic matter (DOM) represents one of the largest active carbon reservoirs on Earth. Changes in pool size or composition could have major impacts on the global carbon cycle. Ocean acidification is a potential driver for these changes because it influences marine primary production and heterotrophic respiration. Here we show that ocean acidification as expected for a 'business-as-usual' emission scenario in the year 2100 (900 µatm) does not affect the DOM pool with respect to its size and molecular composition. We applied ultrahigh-resolution mass spectrometry to monitor the production and turnover of 7,360 distinct molecular DOM features in an unprecedented long-term mesocosm study in a Swedish Fjord, covering a full cycle of marine production. DOM concentration and molecular composition did not differ significantly between present-day and year 2100 CO2 levels. Our findings are likely applicable to other coastal and productive marine ecosystems in general.

Abundance, Electron transport System (ETS) activity and respiration rates of pelagic decapods from the Benguela upwelling system during AFR258, D356 and MSM17/3

Decapods were sampled with a 1 m**2 MOCNESS (mainly upper 1000 m) in the northern Benguela Current during three cruises in December 2009, September/October 2010 and February 2011. Although pelagic decapods are abundant members of the micronekton community, information about their ecophysiology is very limited. Species-specific regional distribution limits were detected for various decapod species (e.g. Plesionika carinata, Sergestes arcticus, Pasiphaea semispinosa). Significant diel vertical migration patterns were determined for three caridean and three penaeiodean species. Biomass was variable and ranged from 23 to 2770 mg dry mass m**-2 with highest values for P. semispinosa. Fatty acid and stable isotope analyses revealed that the examined decapod species are omnivorous tocarnivorous except for the herbivorous to omnivorous species P. carinata. Calanid copepods such as Calanoides carinatus were identified as an important prey item especially for caridean species. Community consumption rates of pelagic decapods derived from respiration rates ranged from 7 mg C m**-2 d**-1 (231S) to 420 mg C m**-2 d**-1 (191S, 171S). A potential active respiratory carbon flux was calculated for migrating pelagic decapods with 4.4 mg C m**- d**-1 for the upper 200 m and with 2.6 mg C m**-2 d**-1 from the base of the euphotic zone to a depth of 600 m. Overall, pelagic decapods apparently play a more prominent role in the northern Benguela Current ecosystem than previously assumed and may exert a substantial predation impact on calanid copepods (up to 13% d**-1 of standing stock).

Graphene foam functionalized with electrodeposited nickel hydroxide for energy applications

The need of new systems for the storage and conversion of renewable energy sources is fueling the research in supercapacitors. In this work, we propose a low temperature route for the synthesis of electrodes for these supercapacitors: electrodeposition of a transition metal hydroxide–Ni(OH)2 on a graphene foam. This electrode combines the superior mechanical and electrical properties of graphene, the large specific surface area of the foam and the large pseudocapacitance of Ni(OH)2. We report a specific capacitance up to 900 F/g as well as specific power and energy comparable to active carbon electrodes. These electrodes are potential candidates for their use in energy applications.