| 1. |
- Yi, Chuixiang, et al.
(författare)
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Climate control of terrestrial carbon exchange across biomes and continents
- 2010
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Ingår i: Environmental Research Letters. - : IOP Publishing. - 1748-9326. ; 5:3
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Tidskriftsartikel (refereegranskat)abstract
- Understanding the relationships between climate and carbon exchange by terrestrial ecosystems is critical to predict future levels of atmospheric carbon dioxide because of the potential accelerating effects of positive climate-carbon cycle feedbacks. However, directly observed relationships between climate and terrestrial CO2 exchange with the atmosphere across biomes and continents are lacking. Here we present data describing the relationships between net ecosystem exchange of carbon (NEE) and climate factors as measured using the eddy covariance method at 125 unique sites in various ecosystems over six continents with a total of 559 site-years. We find that NEE observed at eddy covariance sites is (1) a strong function of mean annual temperature at mid-and high-latitudes, (2) a strong function of dryness at mid-and low-latitudes, and (3) a function of both temperature and dryness around the mid-latitudinal belt (45 degrees N). The sensitivity of NEE to mean annual temperature breaks down at similar to 16 degrees C (a threshold value of mean annual temperature), above which no further increase of CO2 uptake with temperature was observed and dryness influence overrules temperature influence.
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| 2. |
- Abdoullaye, Doukary, et al.
(författare)
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Permanent genetic resources added to molecular ecology resources database 1 August 2009 - 30 September 2009
- 2010
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Ingår i: Molecular Ecology Resources. - : Wiley. - 1755-098X .- 1755-0998. ; 10:1, s. 232-236
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Tidskriftsartikel (refereegranskat)abstract
- This article documents the addition of 238 microsatellite marker loci and 72 pairs of Single Nucleotide Polymorphism (SNP) sequencing primers to the Molecular Ecology Resources Database. Loci were developed for the following species: Adelges tsugae, Artemisia tridentata, Astroides calycularis, Azorella selago, Botryllus schlosseri, Botrylloides violaceus, Cardiocrinum cordatum var. glehnii, Campylopterus curvipennis, Colocasia esculenta, Cynomys ludovicianus, Cynomys leucurus, Cynomys gunnisoni, Epinephelus coioides, Eunicella singularis, Gammarus pulex, Homoeosoma nebulella, Hyla squirella, Lateolabrax japonicus, Mastomys erythroleucus, Pararge aegeria, Pardosa sierra, Phoenicopterus ruber ruber and Silene latifolia. These loci were cross-tested on the following species: Adelges abietis, Adelges cooleyi, Adelges piceae, Pineus pini, Pineus strobi, Tubastrea micrantha, three other Tubastrea species, Botrylloides fuscus, Botrylloides simodensis, Campylopterus hemileucurus, Campylopterus rufus, Campylopterus largipennis, Campylopterus villaviscensio, Phaethornis longuemareus, Florisuga mellivora, Lampornis amethystinus, Amazilia cyanocephala, Archilochus colubris, Epinephelus lanceolatus, Epinephelus fuscoguttatus, Symbiodinium temperate-A clade, Gammarus fossarum, Gammarus roeselii, Dikerogammarus villosus and Limnomysis benedeni. This article also documents the addition of 72 sequencing primer pairs and 52 allele specific primers for Neophocaena phocaenoides.
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| 3. |
- Chen, Mingming, et al.
(författare)
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Carbon anode in direct carbon fuel cell
- 2010
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Ingår i: International journal of hydrogen energy. - : Elsevier BV. - 0360-3199 .- 1879-3487. ; 35:7, s. 2732-2736
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Tidskriftsartikel (refereegranskat)abstract
- Direct carbon fuel cell (DCFC) is a kind of high temperature fuel cell using carbon materials directly as anode. Electrochemical reactivity and surface property of carbon were taken into account in this paper. Four representative carbon samples were selected. The most suitable ratio of the ternary eutectic mixture Li2CO3-K2CO3-Al2O3 was determined at 1.05:1.2:1(mass ration). Conceptual analysis for electrochemical reactivity of carbon anode shows the importance of (1) reactive characteristics including lattice disorder, edge-carbon ratio and the number of short alkyl side chain of carbon material, which builds the prime foundation of the anodic half-cell reaction; (2) surface wetting ability, which assures the efficient contact of anode surface with electrolyte. It indicates that anode reaction rate and DCFC output can be notably improved if carbon are pre-dispersed into electrolyte before acting as anode, due to the straightway shift from cathode to anode for CO32- provided by electrolyte soaked in carbon material.
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| 4. |
- Ji, Guomin, et al.
(författare)
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Enhanced rectifying performance by asymmetrical gate voltage for BDC20 molecular devices
- 2014
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Ingår i: RSC Advances. - : Royal Society of Chemistry. - 2046-2069. ; 4:32, s. 16537-16544
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Tidskriftsartikel (refereegranskat)abstract
- By applying the asymmetrical gate voltage on the 1,4-bis (fullero[c]pyrrolidin-1-yl) benzene BDC20 molecule, we investigate theoretically its electronic transport properties using the density functional theory and nonequilibrium Greens function formalism for a unimolecule device with metal electrodes. Interestingly, the rectifying characteristic with very high rectification ratio, 91.7 and 24.0, can be obtained when the gate voltage is asymmetrically applied on the BDC20 molecular device. The rectification direction can be tuned by the different gate voltage applying regions. The rectification behavior is understood in terms of the evolution of the transmission spectrum and projected density of states spectrum with applied bias combined with molecular projected self-consistent Hamiltonian states analyses. Our finding implies that to realize and greatly promote rectifying performance of the BDC20 molecule the variable gate voltage applying position might be a key
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| 5. |
- Jiang, Bin, et al.
(författare)
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Topological structure of urban street networks from the perspective of degree correlations
- 2014
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Ingår i: Environment and Planning, B. - : SAGE Publications. - 0265-8135 .- 1472-3417. ; 41:5, s. 813-828
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Tidskriftsartikel (refereegranskat)abstract
- Many complex networks demonstrate a phenomenon of striking degree correlations: that is, a node tends to link to other nodes with similar (or dissimilar) degrees. From the perspective of degree correlations, in this paper we attempt to characterize topological structures of urban street networks. We adopted six urban street networks (three European and three North American), and converted them into network topologies in which nodes and edges represent individual streets and street intersections, respectively, and compared the network topologies with three reference network topologies (biological, technological, and social). The urban street network topologies (with the exception of Manhattan) showed a consistent pattern that distinctly differs from the three reference networks. The topologies of urban street networks lack striking degree correlations in general. Through reshuffling the network topologies towards, for example, maximum or minimum degree correlations while retaining the initial degree distributions, we found that all the surrogate topologies of the urban street networks, as well as the reference ones, tended to deviate from small-world properties. This implies that the initial degree correlations do not have any positive or negative effect on the networks’ performance or functions.
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| 6. |
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| 7. |
- Liu, Yu-peng, et al.
(författare)
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应用酶热生物分析仪快速测量血糖的研究分析
- 2013
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Ingår i: Journal of Clinical and Experimental Medicine. ; 12:8, s. 579-581
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Tidskriftsartikel (refereegranskat)abstract
- Objective To compare the enzyme thermistor bioanalysis equipment with blood glucose meter which is analyzed by automatic biochemical analyzer, validate the correct rate of this equipment. The long-term aim of the project was to develop a prototype for a bedside monitor system for semi-continuous monitoring of the blood glucose concentration. This was made possible by using the special advantage of the thermal sensor technique in combination with the adjustment of flow. Methods 150 patients were collected in our department. The glucose level was determined using a single channel enzyme thermistor device. Then the results were compared with lab biochemistry analysator. Results There was no significant difference between these two methods (P>0.05). The measuring method with single channel enzyme thermistor device is a reliable method in determining blood glucose level. Single channel enzyme thermistor keep a coincidence with automatic biochemical analyzer. The assay cycle time was 3 minutes. Comparative analysis between our device and the clinical system device showed an excellent correlation for 150 patient blood samples. The device was stabile for hundreds of injections over a period of 45 days. Conclusion Determined glucose in whole blood using a single channel Enzyme Thermistor device can be used to assess the severity of an illness and for evaluating therapeutic efficacy. The ability of the device to analyze whole blood without any pretreatment makes it possible to develop real-time analysis.
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| 8. |
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| 9. |
- Na, Zhao, et al.
(författare)
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Liquid-phase and solid-phase microwave irradiations for reduction of graphite oxide
- 2014
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Ingår i: Chinese Physics B. - : IOP Publishing. - 1674-1056. ; 23:12, s. 128101-
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Tidskriftsartikel (refereegranskat)abstract
- In this paper, two microwave irradiation methods: (i) liquid-phase microwave irradiation (MWI) reduction of graphite oxide suspension dissolved in de-ionized water and N, N-dimethylformamide, respectively, and (ii) solid-phase MWI reduction of graphite oxide powder have been successfully carried out to reduce graphite oxide. The reduced graphene oxide products are thoroughly characterized by scanning electron microscopy, atomic force microscopy, X-ray photoelectron spectroscopy, Fourier transform infrared spectral analysis, Raman spectroscopy, UV-Vis absorption spectral analysis, and four-point probe conductivity measurements. The results show that both methods can efficiently remove the oxygen-containing functional groups attached to the graphite layers, though the solid-phase MWI reduction method can obtain far more efficiently a higher quality-reduced graphene oxide with fewer defects. The I( D)/ I( G) ratio of the solid-phase MWI sample is as low as 0.46, which is only half of that of the liquid-phase MWI samples. The electrical conductivity of the reduced graphene oxide by the solid method reaches 747.9 S/m, which is about 25 times higher than that made by the liquid-phase method.
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| 10. |
- Qu, Yanhua, 1974-, et al.
(författare)
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Ground tit genome reveals avian adaptation to living at high altitudes in the Tibetan plateau.
- 2013
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Ingår i: Nature communications. - : Springer Science and Business Media LLC. - 2041-1723. ; 4, s. 2071-
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Tidskriftsartikel (refereegranskat)abstract
- The ground tit (Parus humilis) is endemic to the Tibetan plateau. It is a member of family Paridae but it was long thought to be related to the ground jays because of their morphological similarities. Here we present the ground tit's genome and re-sequence two tits and one ground jay, to clarify this controversially taxonomic status and uncover its genetic adaptations to the Tibetan plateau. Our results show that ground tit groups with two tits and it diverges from them between 7.7 and 9.9 Mya. Compared with other avian genomes, ground tit shows expansion in genes linked to energy metabolism and contractions in genes involved in immune and olfactory perception. We also found positively selected and rapidly evolving genes in hypoxia response and skeletal development. These results indicated that ground tit evolves basic strategies and 'tit-to-jay' change for coping with the life in an extreme environment.
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