Wyniki wyszukiwania

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Multi-grid model for crowd's evacuation in ships based on cellular automata

100%

Chen M., Han D.

Polish Maritime Research

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2015

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tom 22

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nr Special Issue S1

In order to enhance the authenticity and accuracy simulation of passengers’ evacuation in ships, a new multi-grid model is proposed on the basis of cellular automata theory. By finer lattice the multi-grid model could enhance the continuity of passengers’ track and the precision of boundary’s qualification compared with traditional cellular automata model. Attraction, repulsion and friction are also quantized in the multi-grid model to present the impact of interaction force among pedestrians. Furthermore, crowd’s evacuation simulated by traditional cellular automata and multi-grid model in single exit room and typical cabin environment have been taken as examples to analyze crowd’s motion laws. It is found that the laws of passengers’ evacuation simulated by the two models are similar, and the simulation authenticity and accuracy is enhanced by the multi-grid model

2

Effects of landuse change on CH4 soil-atmospheric exchange in alpine meadow on the Tibetan Plateau

51%

Guo X., Du Y., Han D., Xu X., Zhang F., Lin L., Li Y., Liu S., Ouyang J., Cao G.

Polish Journal of Environmental Studies

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2015

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tom 24

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nr 4

Degradation of shrub meadows and reclamation of alpine meadows may heavily affect the soil sink for atmospheric methane (CH₄), but this is poorly understood. Therefore, in situ measurements of atmospheric CH₄ consumption were conducted in four landuse types: natural alpine meadow (NM), Elymus nutans pasture (EP), herbaceous meadow in shrub (HS), and a P. fruticosa shrub meadow (PS) within two years. CH₄ fluxes were measured using static chambers and gas chromatography. All four types of land use showed atmospheric CH₄ sink throughout the two years, with mean soil CH₄ consumption rates at 24.6±10.9, 33.8±15.0, 39.8±10.3, and 28.1±12.1 µg CH₄·m⁻²·hr⁻¹ for NM, EP, PS, and HS, respectively. Soil CH₄ consumption increased by 40% by reclamation from NM to EP, while it decreased by 30% by degradation from PS to HS. Soil CH₄ consumption in four types of land use was significantly correlated with temperature at 5 cm depth (P<0.01) and the soil water-filled pore space (WFPS) (P<0.05). Temperature showed stronger effects on soil CH₄ consumption than WFPS, except in NM. UV radiation was positively correlated with soil CH₄ consumption with increasing temperature and decreasing soil moisture. These findings indicate that a decrease in the grazing pressure in shrub meadows and increase in the area of artificial pasture reclaimed from alpine meadows would enhance the CH₄ sink in alpine meadows on the Tibetan Plateau.

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Aerobic methane emission from plant: comparative study of different communities and plant species of Alpine meadow

51%

Guo X., Du Y., Li J., Liu S., Han D., Li Y., Lin L., Zhang F., Oyang J., Cao G.

Polish Journal of Ecology

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2015

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tom 63

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nr 2

This study was aimed at qualifying the methane emission ability of different communities in alpine meadow, and monitoring if the dominant species from these communities could emit methane in a sand culture experiment. Using the static chamber technique and gas chromatography method, two experiments were conducted in the field and in laboratory. First, the methane flux rate was measured in plant communities: natural alpine meadows (NM), Elymus nutans pasture (EP), herbaceous community in shrub (HS), and a Poa fruticosa meadow (PS). A 3-month sand culture experiment was conducted to show the non-microbial methane emission from living plants. Average methane emission rates were estimated to be 16.83 µg m⁻² h⁻¹(range -49.3–107.8), 28.49 µg m⁻² h⁻¹ (range -55.0–96.2) and 20.91 µg m⁻² h⁻¹ (range -31.9– 145.8) for NM, EP, and PS, respectively. Methane emission rate from EP was significantly higher than from NM during the growing season. The reclaim of grassland would enhance the methane emission in this aera through this one year's measurement, but whether this conclusion suit to the whole Tibet Plateau, it remains further longer time and larger spatial scale experiments to verify it. The result of the sand culture experiment showed that some plant species emitted methane in an aerobic, nonmicrobial environment, most of herbaceous species showed a methane emission characteristic, the methane emission from plant may have a species dependent characteristic.

4

Gastrointestinal nematodes infections and anthelmintic resistance in grazing sheep in the Eastern Inner Mongolia in China

51%

Han T., Wang M., Zhang G., Han D., Li X., Liu G., Li X., Wang Z.

Acta Parasitologica

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2017

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tom 62

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nr 4

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Identification and analysis of the SAURs in Prunus sibirica

51%

Yan X., Yi R., Bao W., Rula S., Bai Y., Chen J., Lin Y., Huang H., Han D., He Y.

Dendrobiology

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2024

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tom 91

Ograniczanie wyników

Multi-grid model for crowd's evacuation in ships based on cellular automata

Effects of landuse change on CH4 soil-atmospheric exchange in alpine meadow on the Tibetan Plateau

Aerobic methane emission from plant: comparative study of different communities and plant species of Alpine meadow

Gastrointestinal nematodes infections and anthelmintic resistance in grazing sheep in the Eastern Inner Mongolia in China

Identification and analysis of the SAURs in Prunus sibirica