黄土高原

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

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。

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。

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。

Stochastic dynamic water balance model ; numerical model ; loess plateau

随机动力学水平衡模型；数值模型；黄土高原

The validity of the modified stochastic dynamic water balance model is verified by long term experimental data of winter wheat field in loess plateau.

本文用黄土高原长武农业生态试验站的冬小麦长期定位试验资料对改进的随机动力学水平衡模型进行了准确性检验。

Stochastic dynamic water balance model ; water cycling ; loess plateau

随机动力学水平衡模型；水量转化；黄土高原

Whether rainy year or dry year,semiarid or subhumid region,the site evaporation account for a largeproportion in the total water consumption,transpiration next,crown interception and surface runoff smallest,butthe importance of artificial regulation is:evaporation＞runoff＞anspiration＞crown interception.

黄土高原人工林系统耗水量，无论丰水年或枯水年，均以林地蒸发耗水最大，其次为林木蒸腾、林冠截留，地表径流最小。其人工调控的重要性以林地土壤蒸发位居第一，地表径流远在林冠截留甚至林木蒸腾之上。

On the basis of the distribution and physical geographical characteristics of species endemic to China, the flora of Kongtong Mountain belongs to: subregion of Loess Plateau,North China region. Si no-Japan forest subkingdom, Holarctic kingdom.

根据种、中国特有种和建群种的分布情况及自然地理特征，本区系应隶属于：泛北极植物区、中国—日本森林植物亚区、华北地区、黄土高原亚地区。

Objective To study the fauna of Fanniidae in subregion Loess plateau of China.

目的调查研究我国黄土高原亚区厕蝇科昆虫种数、分布及区系特征。

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。