查询词典 sand dunes

Photo of the Day January 24, 2008 Sand Dunes, The Dalles, Oregon, 2001 Photograph by Jim Richardson In a curious juncture, a wrinkled span of desert dunes pours into the Columbia River Gorge in The Dalles, Oregon.

位于俄勒冈州，达拉斯有一个古怪的结合点那就是具有皱纹横越沙漠，沙丘涌入哥伦比亚河的峡谷。

Plain widespread sand dunes, sand dunes relative height of 15-20 meters, up to 50 meters.

平原上沙丘广布，沙丘相对高度15—20米，最高可达50米。

The sand dunes analyses data have shown they mainly consist of well sorted, symmetry skewness and find sands, and the kurtosis peak is narrow or very narrow. There are abundant impacts of mechanic process on the surface of quartz grains. The traces of eolian process often superpose on the traces stamped by river and beach processes. The dish--shaped concavities and mechanic pits are the most common surface textures, but the barchan concavities and curved grain edges are indicated the marks by eolian environment. The heavy minerals assemblages of coastal dunes are dominated by relatively high specific gravity which have stable chemical properity suggesting the mordern high dynamic environments of coast area. The depositional structures of coastal dunes are typified by corss--bed sets composed of steep foreset laminates and gentle windward dipping sets. It also contains some shell fragments and strong worn foraminiferal tests that are impossibly found in inland desert. On the other hand, the sandy deposits of the continental shelf of East China Sea are with wide range of grains, and the depositional pattens are quite complicated.

海岸沙丘是晚全新世以来相对稳定的海平面背景下的海岸带风成堆积，其沉积特征是以细沙为主，分选好，搬运方式以跃移占绝对优势，偏度上近对称，峰态窄到很窄；石英颗粒表面机械作用形态丰富，风成作用形态叠加于河流和海滩过程形态之上，碟形坑和撞击麻点是最为常见的表面形态，而新月形坑和曲脊是其指示性的特征标志；沙丘沙重矿物以化学性质稳定、比重较大的种类为主，反映了海岸带目前的高能动力环境；海岸沙丘沙的沉积构造以高角度前积层和低角度顶积层组成的交错层理为典型特征，同时还含有少量内陆沙漠所没有的少量贝壳碎屑和强烈磨损的有孔虫壳体。

Microbiotic crusts had a high capacity of evaporation than the shifting sand dunes. During the evaporation process of one week after rainfall, the total evaporation in artificial vegetation regions constructed in 1956, 1964, and 1981 were 6.05, 4.99 and 4.23 times respectively as the total evaporation in shifting sand dunes.

微生物结皮有着比流沙区更高的蒸发能力，在雨后一周的蒸发过程中，1956、1964和1981年人工植被区的总蒸发量分别是流沙区总蒸发量的6.05、4.99和4.23倍。

Caragana intermedia is a psammophilous shrub and one of the commonly occurred species in fixed and semi-fixed sand dunes in Otindag Sand Land and MU US Sand Land.

中间锦鸡儿是浑善达克沙地和毛乌素沙地固定和半固定沙丘上常见的一种沙生灌木。

The analyses of social and economic development indicate that, up to 1998, the total population in Yijinholo County is 143, 949 persons, the population density is 24 persons per square kilometer, large population number results in land exploitation for food and overgrazing in rangeland. The change in temporal and spatial pattern of landuse from 1977 to 1998 demonstrates that mobile sand dunes was replaced by rangeland and woodland and partial shrubland in the middle of study area changed into rangeland and farmland from 1977 to 1987, while mobile sand dunes and rangeland transformed into shrubland and farmland in a small parts from 1987 to 1998, the above-mentioned change is proved by the change of fractal dimension index and fragmentation index at landscape and its element levels.

对近50年来伊旗社会经济发展的分析结果表明，虽然人口增长率基本上呈下降趋势，但由于人口基数较大，截至1998年底，伊金霍洛旗的人口总数达143949人，人口密度为24人／平方公里，较高的人口密度带来了更多的生存需求，使得大量的草牧场被开垦，而剩余的则严重超载。1977-1998年间伊土地利用结构总体格局变化的分析结果表明，1977-1987时段内主要是流动沙地为草牧场和乔木林地所取代，伴随着中部的部分灌木林地转换为草牧场和农地：而1987-1998时段内主要是草牧场和流沙地为灌木林地和农地特别是灌木林地所取代，而景观及各景观要素的分维度指数和破碎度指数的变化也充分证实了这一结论，虽然在前10年（1977-1987年）中大面积的灌木林被砍伐，但土地利用格局的整体变化间接地反映出该时段内荒漠化的状况正在发生逆转。

This sea of sand formed many crescent-shaped sand hills, sand dunes and ridges reaching a height of around 90 meters.

这一片沙海，形成许多平均高达90米左右的新月形沙丘、沙岗和沙脊。

Unless you're running up and down sand dunes immersing the entire shoe and ankle in sand, the gaiters will do their job at keeping the shoes sand-free.

只要你不是在沙丘上来回跑并将整只鞋和脚踝踩入沙中，鞋罩就能有效地防止沙子进入鞋内。

After the dunes, such as tree cover, Kou looming, like the clouds as stunning; psammophila, Mao Liu dotted on the sand dunes, like the reed in Lake Naivasha, a clusters of, clumps, clusters of color is different clumps posture dissimilar; breeze light Buddha, Ying Chi's green like a lake-like rippling blue waves.

沙丘后如盖的树寇若隐若现，像云朵般美伦美奂；沙柳、毛柳点缀在沙丘上，恰似沙湖中的芦苇丛，一簇簇，一丛丛，簇簇色不同，丛丛姿相异；微风轻佛，盈尺的绿草犹如湖水般碧波荡漾。

The study area in the semi-arid environment where the wind energy is medium and wind blows from single direction; the value of sand dune mobility is small. In the study areas blowouts develop on thick sandy alluvial deposits and undulated vegetated sand dunes. Its intensively locates in the upper windward side of dunes or other inclined terrain.

研究区风蚀坑处在中风能单向风况和沙丘活动性指数较低的半干旱草原环境，主要分布于沙源丰富的河湖相沙质沉积物和缓起伏固定沙丘地，集中出现在梁岗丘陵和固定沙丘等斜坡地形迎风面上部。

The absorption and distribution of chromium were studied in ryeusing nutrient culture technique and pot experiment.

采用不同浓度K2CrO4(0，0.4，0.8和1.2 mmol/L)的Hoagland营养液处理黑麦幼苗，测定铬在黑麦体内的亚细胞分布、铬化学形态及不同部位的积累。

By analyzing theory foundation of mathematical morphology in the digital image processing, researching morphology arithmetic of the binary Image, discussing two basic forms for the least structure element: dilation and erosion.

通过分析数学形态学在图像中的理论基础，研究二值图像的形态分析算法，探讨最小结构元素的两种基本形态：膨胀和腐蚀；分析了数学形态学复杂算法的基本原理，把数学形态学的部分并行处理理念引入到家实际应用中。