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11.
A combined approach of remote sensing (RS) and geographical information systems (GIS) was used in this study to identify the impact on urban surface radiant temperature (SRT) of urban green-space change. Urban SRT increases as green-space area is converted into non-green-space area. Also, well preserved green space and newly connected green space contribute to a decrease of the SRT. Seoul Metropolitan area is rapidly expanding. Existing urban SRT studies have, however, mainly been conducted for Seoul City. The most rapidly expanding area in Korea is now the Seoul suburban area, for example the Mt Gwanggyo area. Although changes of SRT and normalized difference vegetation index (NDVI) as a result of land-use change have been measured in many other studies, the results in these studies were derived from data from different seasons. Also, these studies did not examine a newly expanding area. Considering these problems, the same seasonal multitemporal data were used in this study to derive the SRT change for the same season in different years. This study confirmed the importance of effective management and location of urban green space for urban SRT mitigation. Ultimately, the impact on urban SRT of urban green-space change should be regarded as an important factor in urban planning. 相似文献
12.
The photosynthetic and growth characteristics of Mosla hangchowensis, an endangered species and M. dianthera, a weed, were compared under three irradiances (PPFD) similar to shaded forest understory, forest edge and open land. Both
species grown at lower PPFD had lower PPFD-saturated photosynthetic rate (Pmax), saturation PPFD, compensation PPFD, apparent quantum yield, total mass and root/shoot ratio and higher specific leaf area,
leaf area ratio and height ratio. At the same PPFD treatment, however, specific leaf area and leaf area ratio of M. hangchowensis were higher than those of M. dianthera, other above parameters were lower than those of M. dianthera. Water use efficiency did not differ between M. hangchowensis and M. dianthera, but it reached its maximum at 70 % of full PPFD. These results suggested the optimum habitat of M. hangchowensis is the forest edge. 相似文献
13.
SOLWEIG 1.0 – Modelling spatial variations of 3D radiant fluxes and mean radiant temperature in complex urban settings 总被引:1,自引:0,他引:1
The mean radiant temperature, Tmrt, which sums up all shortwave and longwave radiation fluxes (both direct and reflected) to which the human body is exposed is one of the key meteorological parameters governing human energy balance and the thermal comfort of man. In this paper, a new radiation model (SOLWEIG 1.0), which simulates spatial variations of 3D radiation fluxes and Tmrt in complex urban settings, is presented. The Tmrt is derived by modelling shortwave and longwave radiation fluxes in six directions (upward, downward and from the four cardinal points) and angular factors. The model requires a limited number of inputs, such as direct, diffuse and global shortwave radiation, air temperature, relative humidity, urban geometry and geographical information (latitude, longitude and elevation). The model was evaluated using 7 days of integral radiation measurements at two sites with different building geometries – a large square and a small courtyard in Göteborg, Sweden (57°N) – across different seasons and in various weather conditions. The evaluation reveals good agreement between modelled and measured values of Tmrt, with an overall good correspondence of R 2?=?0.94, (p?0.01, RMSE?=?4.8 K). SOLWEIG 1.0 is still under development. Future work will incorporate a vegetation scheme, as well as an improvement of the estimation of fluxes from the four cardinal points. 相似文献
14.
P. Hoffmann 《Photosynthetica》1998,35(1):1-11
Photosynthesis, as a fundamental element in the life process, is integrated in the evolution of living systems on the basis of hydrogen cycles on various hierarchic levels. Conversion of radiant energy enables the oxidation of water, whereby free oxygen accumulates in the atmosphere. Hydrogen is (reversibly) stored in organic materials formed under reductive CO2-fixation and by the incorporation of the other elements, which are necessary for living systems. All endergonic processes in living cells are finally driven by the energy released through the clean recombination of protons and electrons with oxygen to water. Duration of the stored energy and the complexity of the systems thus produced is correlated negatively with the conversion efficiency of the radiation energy. Entropy is a unifying principle in the evolution of living systems, inclusive human societies. 相似文献
15.
During an open-top chamber experiment performed in a mountain stand of young (12-year-old) Norway spruce (Picea abies [L.] Karst.), the trees were exposed to one of two CO2 concentrations (ambient CO2, AC, or AC + 350 μmol mol-1 = elevated CO2, EC) continuously over three growing seasons. To evaluate the EC influence, measurements of the relations between the rate
of net CO2 uptake (P
N
) and incidental photosynthetically active photon flux density (PPFD), as well as the content of photosynthetic pigments and
chlorophyll (Chl) a fluorescence were taken in the third growing season. The short-term response to EC was evident mainly
on ribulose-1,5-bisphosphate carboxylase/oxygenase kinetics without any significant change to the utilization of radiant energy.
The long-term effect of EC was responsible for a decrease in P
N
, content of Chl a + b, Fv/Fm ratio, quantum yield of fluorescence, and photochemical quenching. Changes of stoichiometry between the electron transport,
Calvin cycle and the end-product synthesis were confirmed for responses to the long-term import of EC and led to a definition
of the photosynthetic acclimation to EC in Norway spruce.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
16.
东亚飞蝗耐高温能力及其体温调节行为 总被引:4,自引:0,他引:4
为明确东亚飞蝗Locusta migratoria manilensis的耐高温能力和体温调节行为, 采用高温饲养、提供辐射热源和风力等方法, 对东亚飞蝗各发育期的高温耐受能力、体温(body temperature, Tb)与环境温度(air temperature, Ta)和辐射温度(radiant temperature, Tr)的关系、飞蝗对辐射热的选择行为、体温升高速率以及辐射角度和风力对体温的影响进行了研究。结果表明: 东亚飞蝗44℃下饲养, LT90 最长为326.4 h; 50℃下, LT90可达20.6 h。无辐射热条件下, Tb随Ta的上升而升高, 当Ta升至32℃, 蝗虫出现体温调节行为; Ta以0.5℃/min速率上升时, 出现体温波动的个体数占试虫总数的53.7%, Tb平均波动温差为1.15℃, 平均波动时间为5.2 min, Tb平均波动起始温度为47.2℃, 成虫致死时间略长于若虫。有辐射热条件下, 随笼顶辐射温度的逐渐升高, 飞蝗趋向选择温度相对较低的笼底, 试虫体温调节较无辐射热条件下强; 辐射角度和风力均对飞蝗的体温有显著影响。结果显示东亚飞蝗对高温的耐受能力较强, 并且具有明显的体温调节行为, 可调节体温达到最佳生理状态。 相似文献
17.
Jörg Trojan Dieter Kleinböhl Annette M. Stolle Ole K. Andersen Rupert Hölzl Lars Arendt-Nielsen 《Somatosensory & motor research》2013,30(1):11-17
Distortions of the body image have been repeatedly reported for various clinical conditions, but direct experimental analyses of the perceptual changes involved are still scarce. In addition, most experimental studies rely on cerebral activation patterns to assess neuroplastic changes in central representation, although the relationship between cerebral topography and the topology of the perceptual space is not clear. This study examines whether the direct psychophysical mapping approach we introduced recently (Trojan et al., Brain Res 2006;1120:106–113) is capable of tracking perceptual distortions in the somatotopic representation of heat-pain stimuli. Eleven healthy participants indicated the perceived positions of CO2 laser stimuli, repetitively presented to the dorsal forearm, with a 3D tracking system in two consecutive sessions, separated by the topical application of capsaicin cream. In line with earlier reports, we expected that the resulting individual perceptual maps (i.e., one-dimensional projections of the perceived positions onto the forearm surface) would be subject to modulation through the altered sensory input, to be measured in terms of altered topological parameters. We found that the topology and metrics of the somatotopic representation were well preserved in the second session, but that the perceptual map was compressed to a smaller range in 9 out of 11 participants. By providing dimensional measures of perceptual representations, perceptual maps constitute an independent, genuinely psychological complement to the topography of cortical activations measured with neuroimaging methods. In addition, we expect them to be useful in diagnosing pathological changes in body perception accompanying chronic pain and other disorders. 相似文献
18.
《Animal : an international journal of animal bioscience》2016,10(1):128-134
It has been documented that floor heating of the farrowing area in loose housed sows improves survival of piglets significantly. However, today, the majority of farrowing pens are designed with crating of sows and slatted floor at the birth site. The aim of this study was to investigate whether providing radiant heat at the birth site to new-born piglets in pens with crated sows reduced hypothermia, time to first milk intake and growth of the piglets during the 1st week. Second parity Danish Landrace×Yorkshire sows (n=36) were randomly divided into two groups: Control (CG) and heat (HG). In the area behind the sow (zone 1), two radiant heat panels were mounted above the slatted floor in the HG. The farrowings were attended, and the heaters were turned on at birth of first piglet and turned off 12 h after. Birth time, time to leave zone 1, time to first contact with udder and time to first suckling were registered by direct observation. The piglet’s rectal temperature (RT) was measured 15, 30, 60, 120, 180, 240 min after birth and 12, 14 and 24 h after birth of first piglet. Piglets were weighed at birth, 24 and 48 h and 7 days after birth. Data were analysed in a mixed model in SAS. The drop in RT was lower in HG compared with CG (P=0.002), and the RT in HG remained higher than in CG from 30 to 240 min after birth (P<0.05), whereas no difference was found at 12 h after birth of first piglet (P=0.92). Piglets in HG stayed longer in zone 1 than those in CG (P=0.01), whereas time to reach udder (P=0.35) and to first suckling (P=0.56) did not differ. No difference in weight gain was found between piglets in HG and CG at 24 h (P=0.23), 48 h (P=0.28) and 7 days after birth (P=0.44). Birth weight had a positive effect on RT (P<0.001) and reduced time to leave zone 1 (P<0.01), reach udder (P<0.001) and time to first suckling (P<0.001). The results showed that radiant heating behind the sows reduced hypothermia in new-born piglets and indicate that providing heat during the first half hour after birth is important. 相似文献
19.
20.
Krzysztof Blazejczyk Håkan Nilsson Ingvar Holmér 《International journal of biometeorology》1993,37(3):125-132
Different methods have been compared for the estimation of solar heat load on man. The comparison comprised several methods based on the calculation of absorbed solar radiation and one method for calculation of mean radiant temperature (Mrt). Regression analysis was carried out for predicted values and values calculated for a vertical cylinder, assumed as an analog model of a standing man. Regression of mean skin temperature, measured in 10 subjects exposed to solar radiation under a variety of climatic conditions, on predicted radiant heat load was also analysed. Mean skin temperature correlated best withMrt, accounting for more than 50% of the variance. The results indicated that three methods provide a realistic estimation of the radiation heat load, whereas some methods show deviations of several hundred per cent. 相似文献