沙丘

The changing trend was induced by area fluctuation of semi-mobile and semi-fixed dunes because 2.6% area of semi-mobile dunes and 12.3% area of semi-fixed dunes were unchangeable during 1987 to 1995. And, most changeable area of the semi-mobile and the semi-fixed dunes transferred to other sand-dune types and cropland.

沙漠化程度的变换主要是由半流动和半固定沙丘的变化所导致，其中在1987-1995年期间，半流动和半固定沙丘分别只有2.6%和12.3%保持不变，其余部分主要转移成其他沙丘类型和农田。

At the South Edge of the Tengger Desert, the sampled sites of mobile sanddune, semi-fixed sand-dune and fixed sanddune were selected as the different stages of the reversion process of desertification with the method of substituting time with space, and topsoil mineral elements of the decertified land were studied reversion process of desertification.

以腾格里沙漠南缘沙漠化土地为研究对象，应用时空替代法选择流动沙丘、半固定沙丘、固定沙丘的沙漠化逆转序列样地，研究了沙漠化逆转过程土壤矿质元素的变化特征。

The results showed that the total vegetation coverage, shrub and undershrub coverage decreased; herbage coverage increased.

结果表明：从固定沙丘、半固定沙丘到流动沙丘，总盖度、灌木盖度下降，草本盖度增加。

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。

Therefore, the surface pressure is the important basis of studying surface geomorphic process of dune.

风成沙丘表面压力分布特征直接反映沙丘表面风蚀风积特点，因而是研究沙丘表面地貌过程的重要依据。

Surface-consistent deconvolution using variable prediction step, and suppression of sand dune ringing;2. Spatiotemporal distribution of moisture content in sand dune s of the unirrigated forestation along the southern marginal zone of Gurbantunggut Desert;3. The concepts of sand land, sand dune and desertified land etc.

在实地调查和多年定位研究的基础上，根据目前沙漠化过程研究的需要，介绍了沙地、沙丘、沙漠化土地等相关概念及其主要区别，阐述了沙地、沙丘、沙漠化土地类型的划分标准以及类型互换使用中应该注意的问题；通过分析影响沙漠化发展方向和过程的关键因素，建立了沙漠化正、逆发展过程的地面判别指标体系，并讨论了不同类型沙丘的主要来源、发展方向及转换过程的判别方法。

It is known for its dramatic dunes, including the crescent-shaped barchan dunes shown here, some of which can reach 100 feet (30 meters) high and 1,200 feet (370 meters) wide.

这里因有着壮观的沙丘而知名，比如图中的这些半月状的弧形沙丘，有些沙丘甚至可高达100英尺(30米)，宽达1，200英尺(370米)。

It is known for its dramatic dunes, including the crescent-shaped barchan dunes shown here, some of which can reach 100 feet (30 meters) high and 1,200 feet (370 meters) wide.

纳米布沙漠因它壮丽的沙丘闻名于世，包括像照片显示的这种新月形的沙丘，其中一些沙丘可以达到100英尺（30米）高和1200英尺（370米）宽。

Field measurement of surface wind velocity and sediment transport rates was made on barchan dune in Wulanbuhe desert to understand. The results show that the wind velocities increasing upon windward slopes of the dunes vary with both slope morphology and wind velocity at the foot of the dunes.

对乌兰布和沙漠新月形沙丘表面风速的野外观测结果表明，沙丘迎风坡气流加速量主要和沙丘坡面形态、迎风坡前来流风速有关，迎风坡风速放大率介于1.02~1.59之间。

After using the forestation method of spray sowing and inserting dry seedlings, the area of fouryearnaturalregeneration poplar and willow has taken up 5 percent of controlled area, with the area of artificialspraysowing poplar and willow taking up ten percent and the area of artificialspraysowing shrub and herbage ta...

采用喷播和深松插干造林方法，4年天然更新的杨树和柳树占治理面积的5%左右，人工栽培的杨树和柳树占10%，人工喷播的灌木、牧草占10%。在沙丘上部植被覆盖度由10%～15%增加到40%～50%，丘间低地和风蚀洼平地由50%～60%增加到75%～85%。流动沙丘初步恢复为疏林草地型固定与半固定沙丘。

The split between the two groups can hardly be papered over.

这两个团体间的分歧难以掩饰。

This approach not only encourages a greater number of responses, but minimizes the likelihood of stale groupthink.

这种做法不仅鼓励了更多的反应，而且减少跟风的可能性。