黄土

Stand on a base of upper study, this paper choose distribution map of agriculture and stock raising in seven different historical age as basic material, sum up ten agro-geology environmental factors into Loess plateau Area's AEG system, and cover all these factor's component parts map on distribution draft of every period's agricultural and pastrol, then measure the occupying proportion, bring results into fomula of factor information entropy, finally, take average value of ten factor's information entropy in each period as its characteristical AEG system entropy value.

在以上研究的基础上，论文选择黄土高原地区七个历史时期的农牧业分布图作为基本资料，将该区的十个地质环境要素纳入农业环境地质系统中，将其类别分布图与上述农牧业分布图进行叠加量测，结果代入要素系统熵计算公式，求得了十个农业地质环境要素在各个历史时期中的系统熵，对每个历史时期的这十个熵值求算术平均值就获得了该历史时期黄土高原地区总的农业环境地质系统熵。

Physical composition and microstructure of loess have an important significance to research further engineering geological characteristics,collapsibility and its mechanism.

黄土的物质组成和结构特征对深入研究黄土的工程地质特性和湿陷机理具有重要的意义。

Based on this idea, the author has chosen two typical loess sections of Luochuan, and Xifeng for this study, collected the successive loess columns; To probe the conditional experiments of BeO sample preparation and measurement, and improve the existing method; On the basis of the technology improvement, the author has finished 402 samples' BeO preparation and AMS measurement; Also at the same time, to separate quartz from samples at 1 cm interval for both Luochuan and Xifeng sections systematically, to carry out measurements of quartz grain-size, SUS, grey scale, carbonate content and bulk sample density; By using the grain size model, the author has set up the chronological framework for both Luochuan, and Xifeng sections and the time sequence of millennial scale abrupt climate events recorded in loess strata, and reconstructed the East Asian monsoon history over 130ka by using multi proxies; Finally, to discuss the possible mechanisms of palaeoclimatic changes tentatively.

详细地球科学的发展离不开高精度和高分辨率的研究。运用长寿命核素如〓Be作为环境过程的示踪，已成为不可替代的有效工具。本论文选择洛川、西峰两个典型的黄土剖面，连续采集柱状样；探索了BeO样品制备、测量的条件实验，改进了原有的方法，完成了402个BeO样品的制备和AMS测量；同时还系统地分离洛川、西峰剖面高分辨率（1cm）黄土、古土壤样品中的碎屑石英，测量了碎屑石英粒度，以及全样的磁化率、灰度、碳酸盐含量和容重等古气候代用指标；采用粒度年代模式建立了洛川剖面和西峰剖面的年代标尺，建立了黄土地层记录的千年尺度的气候突变事件的时间序列，多指标重建了最近130ka东亚季风变迁史；初步讨论了古气候变迁的可能机制。

According to the "Waterbirds Species List" published by the State Forestry Bureau in 2003,the waterbirds in 8 zoogeographical prefectures and 4 zoogeographical provinces in Shaanxi Province were counted,and the community similarity indices between each zoogeographical prefecture and zoogeographical province were figured out.

河流众多的关中平原省的渭河谷地平原州的水鸟种类最多，有85种，水鸟最少的是干旱的黄土高原省的南部黄土塬土石山地梢林州，仅有23种；群落相似性指数最高的是相邻的黄土塬土石山地梢林州和渭北台塬州。

Secondly, with a triaxial test instrument for unsaturated loess which can work with computerized tomograph carried original Q3 and Q2 loess testing on instantaneously, quantificationally and undamaged scanning. Combining CT images, data and stress-strain curve, this paper divided shearing process into 4 period with respectively analyzing studying.

其次，应用非饱和黄土的三轴CT扫描仪，进行了原状Q_3、Q_2黄土的三轴试验过程的动态、定量、无损的CT扫描，结合CT图像、数据与应力应变关系，对非饱和黄土的剪切过程分4个阶段进行了深入分析研究。

The results indicate that the formation of loess vertical joints can be divided into two phases:① the formation of inner fissure, i.e. in the beginning of deposition, the undulation of terrain leads to uneven distribution of loess, then when it rains uneven collapsibility generates, which leads to generate inner fissures ;② the stage of fissure extension, namely loess continues deposition after the inner fissures have been formed, the increasing of the top pressure makes the top of inner fissure lie in the state of tensile stress, so, when the stress reaches its tensile strength, the inner fissure extends along the vertical direction and then becomes a vertical joint.

结果表明黄土垂直节理的形成可分为 2 个阶段：①内裂隙形成阶段，开始沉积时，由于地形的起伏导致黄土厚度上的分布不均匀，在降雨时产生不均匀湿陷，从而导致产生内裂隙；②裂隙扩展阶段，内裂隙形成后黄土继续堆积，顶部压力的增长致使裂隙顶部土体受到拉应力作用，当达到其抗拉强度时裂隙就会沿竖直方向产生扩张而形成垂直节理。

In order to provide new fine interspecific hybridization cultivar between plum and apricot,and summary high-yield cultivation techniques of Flavorosa,introduction experiment of Flavorosa in P.

为给黄土丘陵区提供优良的杏李种间杂交新品种，并总结出风味玫瑰在豫西黄土丘陵区的丰产栽培技术，在河南省豫西黄土丘陵区进行了风味玫瑰杏李的引种试验。

The critical loess slopes along the highways were the inputted form of slopes and measured values of cohesions and internal friction angles were the reference values of random variants. Monte-Carlo method was used to choose samples and the formula of the Bishop simplified method was regarded as control equation. The reliabilities of the loess high slopes in three positions of Shaanxi Province were simulated. Failure probability and reliability index were obtained.

以极限状态坡作为输入坡型，将陕西黄土地区公路勘察中实测的粘聚力和内摩擦角作为主要随机变量参考值，采用Monte-Carlo法抽样，简化Bishop法公式作为控制方程，对陕西地区3个地段的黄土高边坡进行了可靠度模拟，获得黄土高边坡的失效概率与可靠指标。

The book summary of the engineering properties of loess wall, a wall of loess detailed classification to meet the 350km / h high-speed railway tunnel and the structure of the reasonableness of the requested size of the tunnel section, and in the form of parameters, load characteristics of the loess tunnel wall, Anchor role in the stability of the characteristics of the tunnel and control the key technology design.

本书归纳总结了黄土围岩工程特性，提出了黄土围岩的细化分级，满足350km/h高速铁路和隧道结构合理性要求的隧道断面大小、形式和参数，黄土隧道围岩荷载特征、锚杆作用特点和隧道稳定性控制方法等关键设计技术。

Based on the study of the loess spatial self correlation of the soil property parameter

因此，黄土土性参数统计分析和空间自相关性的研究，对正确评价黄土高边坡的稳定性，提高黄土边坡的设计水平均具有重要的理论和实际意义。

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。