黄土

Then, the quasi-overconsolidation ratio is introduced to consider the effect of super pore pressure; and the fitting formulation is applied to consider the influence of shearing strain. The degenerated formulation of undrained strength of saturated loess is deduced at last; and its reasonableness is proved by the test results.

在此基础上，引入似超固结比的概念来考虑超孔隙水压力的影响，应用拟合公式来考虑剪切变形的影响，最终推导出了饱和黄土不排水强度的退化公式，与试验结果的对比证明了理论公式预测结果的合理性。

In addition, with the progress of runoff scouring, the form of soil erosion changed from sheet erosion to rill erosion.

李勇等(1991)和李勇(1995)通过对黄土高原地区乔灌植被根系与土壤物理性质关系的研究，证

Rare earth element tracer method was used to study sheet erosion changing to rill erosion on slope land.

中国科学院水利部水土保持研究所黄土高原土壤侵蚀与旱地农业国家重点实验室，陕西杨凌712100

Loess hilly region ; sheet flow ; soil erosion ; hydraulic parameter ; dynamic mechanism

黄土丘陵区；薄层水流；土壤侵蚀；水力参数；动力机制

In the paper, we mostly studied the change of soil erosion process by a new REE tracer method, based on the theories of hydraulic mechanical subject and radionuclear tracer method, and simulated rainfall was applied to study the sheet erosion changing to rill erosion and the rill erosion process on slope land. The new REE tracer method should be useful to future studying of erosion processes on slope lands.1. Offering and testifying a new REE displacing method to study on the soil erosion of the loess slope.

本文以黄土坡面土壤侵蚀形态演变规律为研究重点，以新的核素示踪技术为手段，采用水动力学与核素示踪技术相结合、室内人工模拟降雨与稳定性REE元素示踪相结合的方法，利用先进的INAA技术，定量研究了不同雨强次降雨条件下细沟间侵蚀向细沟侵蚀的转变过程、细沟发生发育过程，为深入了解坡面侵蚀过程，建立黄土高原土壤侵蚀预报模型提供了研究基础。

Sienna in different tones for the Cape Castle.

色，海角城堡的不同情调用黄土的不同色调来表现。

The experiments with water as only limiting factor was designed to study the dynamics of size inequality in spring wheat ( Triticum aestivum L.)populations and its theoretical basis.Of the three densitywheat populations,the skew of weight distribution of wheat plants increase with time,and the increase rate is the highest in high density population.

在黄土高原半干旱生态条件下设置了低、中、高3个密度梯度的以水为限制因子的实验，各密度种群个体重量分布偏倚度随时间的延续而增大，增大的幅度随密度增高而上升。

Deep studies on the Holocene loess-palaeosol sequences and the slack water deposits profiles, identifying and obtaining the information of paleoflood recorded in them, ensuring the amount, frequency, time and scale of the extreme Holocene paleofloods, are very helpful in revealing the characters and rules of the environment change during Holocene in this drainage basin and the middle reach of the Yellow River.

深入研究古遗址周围的黄土——古土壤地层和古洪水平流沉积物，识别和获取蕴藏其中的古洪水信息，并以此确定全新世特大古洪水事件发生的次数、频率、时间及规模，有助于揭示伊洛河流域及黄河中游地区全新世环境演变的特点和规律。

During the glacial maximum, Mu Us Desert extended southeasterly to the loess plateau, but when the last climatic optimum occured, the desert retreated more than 5 latitudes northwards.

末次冰期极盛时，毛乌素沙漠的分布范围扩大，向东南一直延伸到黄土高原地区，全新世气候适宜期时，沙漠缩小，相对于末次盛冰期而言，在空间上向北退缩了5个纬度左右。

Fortunately, the desertification degree decreased obviously, and moderate and light desertification took the leading position. From 1986 to 2003, the spatial centroid of desertification landscape patches expanded southwestward and northeastward, giving serious threat to the ecological safety of the southeast and northeast loess gully and hilly areas.

沙漠化程度明显下降，沙漠化主导类型已由严重沙漠化转变为中度和轻度沙漠化。1986-2003年沙漠化景观整体上向西南和东北方向扩展，严重威胁着西南和东北部黄土丘陵区的生态安全。

However, as the name（read－only memory）implies, CD disks cannot be written onorchanged in any way.

然而，正如其名字所指出的那样，CD盘不能写，也不能用任何方式改变其内容。

Galvanizes steel pallet is mainly export which suits standard packing of European Union, the North America. galvanizes steel pallet is suitable to heavy rack. Pallet surface can design plate type, corrugated and the gap form, satisfies the different requirements.

镀锌钢托盘多用于出口，替代木托盘，免薰蒸，符合欧盟、北美各国对出口货物包装材料的法令要求；喷涂钢托盘适用于重载上货架之用，托盘表面根据需要制作成平板状、波纹状及间隔形式，满足不同的使用要求。