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1.
本文研究了吉林省1:50万土地资源图的分类系统原则、依据、标准或指标体系,以及制图方法、颜色设计等制图理论和技术问题,对编制各类土地资源图提供了有力的借鉴。 相似文献
2.
The surface colour and temperature fields of the Mediterranean Sea, as appearing in time series, of basin-wide images available in the CZCS (1979–1985) and AVHRR (1982–1991) historical archives, differentiate between basin interior and continental margins affected by coastal patterns, river plumes, and mesoscale features. The original data were processed to apply calibration factors, to correct for atmospheric contamination, and to estimate chlorophyll-like pigment concentration and surface temperature. Composites were derived, as monthly and annual means, using a fixed equal-area projection with a 1-km2 pixel grid. Enhanced pigment values and lower temperatures along the northern coastal areas (i.e. the Ligurian, Provençal and Balearic basins, as well as the Adriatic, and Aegean Seas) have been associated with the impact of runoff from continental margins (i.e. both a direct impact due to the sediment load and one induced on the planktonic flora by the associated nutrient load) and with vertical mixing due to the prevailing winds (i.e. the Mistral in the northwest, the Bora in the Adriatic, the Etesians in the Aegean). The pattern of increasing pigments and decreasing temperatures in seen to develop in the monthly images from the coastal zone towards the open sea from summer to winter, and then back from winter to summer. The southern coastal areas show different values, namely lower pigments and higher temperatures (except in areas where the data are altered by signal contamination). It is suggested that differences in geomorphology and meteorology of the basin margins have an impact on both water biogeochemistry and dynamics, influencing the biooptical and thermal properties of the various sub-basins, and of the entire Mediterranean region. 相似文献
3.
Sexual selection and cuckoldry in a monogamous songbird: implications for sexual selection theory 总被引:11,自引:0,他引:11
Geoffrey E. Hill Robert Montgomerie Christina Roeder Peter Boag 《Behavioral ecology and sociobiology》1994,35(3):193-199
Sexual selection is generally assumed to be weaker in monogamous than in polygynous animals. Recently, though, extra-pair fertilizations have been hailed as an important force in generating variance in reproductive success among males in socially monogamous species, thereby increasing the intensity of sexual selection. To see if extra-pair copulations contribute to variance in male reproductive success in the house finch (Carpodacus mexicanus), we used DNA fingerprinting to determine the paternity of chicks from 35 nests. This species is a socially monogamous passerine in which plumage brightness serves as a sexually selected indicator of male quality. Out of 119, nestlings 10 (8.3%) were fathered by a male other than the attending male, but cuckoldry occurred randomly with respect to the plumage colouration, size, or age of the attending male. Thus extra-pair fertilizations do not generate variance in male reproductive success with respect to plumage colour. On the other hand, a strongly male-biased sex ratio and asynchronous breeding by females may generate substantial variance in male reproductive success and could explain the evolution of ornamental colouration. 相似文献
4.
Kaspar Delhey Anne Peters Arild Johnsen Bart Kempenaers 《Behavioral ecology and sociobiology》2007,61(6):853-862
Sex-allocation theory predicts that females paired to attractive males should bias the brood sex ratio towards male offspring,
as these would inherit the attractiveness of their father. We studied sex allocation based on male ornamentation in blue tits.
Brood sex ratios varied with male UV coloration in an age-dependent manner. For juvenile males, the proportion of sons increased
with increasing UV ornamentation, which is in agreement with previous findings from a Swedish population. However, the relationship
between UV ornamentation and brood sex ratio was reversed for adult males, with females paired to less UV-ornamented adult
males producing more sons. This pattern fits with the observation that, in our population, less UV-ornamented adult males
sire the majority of extra-pair young. To test the causality of the association between brood sex ratio and male coloration,
we experimentally manipulated crown colour largely within the natural range. We created two groups of males: one with higher
and one with lower UV reflectance, UV(+) and UV(−), respectively. Contrary to our expectations, there was no significant treatment
effect. However, in UV(−), but not UV(+) males, the proportion of sons was negatively correlated with male coloration before
manipulation. This suggests that the UV(−) treatment caused males that were more UV ornamented to decline more in attractiveness,
as shown in a similar experiment in Sweden. However, given that correlational patterns differ between these populations, similarities
in experimental results should not be taken as evidence for consistent patterns of adaptive sex allocation in this species. 相似文献
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6.
Dr. Ulrich Gembruch Molly Chatterjee Rainer Bald Gerd Eldering Helga Göcke Andreas E. Urban Manfred Hansmann 《黑龙江环境通报》1990,10(4):211-217
A case of aortic atresia with insufficiency of mitral valve diagnosed prenatally at 33 weeks of gestation is presented. An accurate diagnosis of this fetal cardiovascular malformation was possible by application of Doppler colour flow mapping, which demonstrated (a) the absence of forward flow in the hypoplastic ascending aorta, (b) reverse flow of blood from the ductus arteriosus into the severely hypoplastic ascending aorta in the late systole, (c) pansystolic mitral valve regurgitation, and (d) absent flow across the foramen ovale as a result of premature closure of the foramen ovale. 相似文献
7.
Sarah A. Collins Christene Hubbard Anne M. Houtman 《Behavioral ecology and sociobiology》1994,35(1):21-25
Studies of female mate preference in zebra finches (Taenopygia guttata) have shown that male beak colour and song rate are important. However, the two characters are correlated. Here the effect of beak colour and song rate on female choice are examined independently. In mate choice tests involving two males, beak colour was manipulated artificially using nail varnish. The results showed that females showed a significant preference for males with a high song rate, but not with a red beak. Females did not prefer males with a red beak if song rate was low and females preferred males with orange beaks who expressed a high song rate. Female preference for males with red beaks was not found when beak and song characters were no longer correlated. 相似文献
8.
白腐菌是一种可有效处理染料废水的丝状真菌 ,它可通过其分泌的特殊的降解酶系或其他机制将各种人工合成的染料彻底降解为CO2 和H2 O ,同时 ,对脱色具有良好的作用。本文就白腐菌的生物学特性及其对染料的降解酶系、机理和白腐菌发酵的主要影响因子、白腐菌处理染料废水的有关研究及应用现状进行了综述 相似文献
9.
Alberto Velando Roxana Torres Irene Espinosa 《Behavioral ecology and sociobiology》2005,58(2):175-180
Sexual selection models suggest that female choice is based on male traits that indicate their genetic or environmental condition, consequently enhancing her reproductive success by direct or indirect benefits. We investigated the relationship between male foot colour and offspring condition in the blue-footed booby, a socially monogamous seabird, with conspicuous and variably condition-dependent coloured feet that are selected by females. In a cross-fostering experiment, we found that chick condition was related to the foot colour of the foster father and, to some extent, to the foot colour of the genetic father; thus overall, the fathers sexual ornamentation (genetic and foster) explained 32% of variance of chick condition. These data suggest that foot colour, a dynamic sexually selected trait, is mostly a signal of parental contribution. In species in which males provide parental care, females may choose mates with higher parental ability. Overall, our data suggest that colourful integuments are honest signals of parental ability.Communicated by J. Graves 相似文献
10.
传统的宝石改色是以泰国的还原热处理工艺为代表,现已逐渐被人们所接受。现代科技与珠宝工艺相结合,出现辐照改变宝石颜色,然而,部分宝石因辐照而带有残余放射性,对消费者造成伤害.本文指出了宝玉石射线来源与防护措施。 相似文献