背景值

pH、有机质和石灰反应对土壤背景值的影响

Effects of pH , Organic Matter and Lime Reaction on Background Value of Soil

对背景值优化的新GM（1,1）模型

Optimization Integrated Background Value for New GM ( 1,1 ) Model

我国地面O3、NOx、SO2背景值的观测研究

Observational analysis of surface o 3 、 NO x and so 2 in China

川西平原岷江流域冲积性水稻土中Be和V的背景值研究

Study background value of beryllium and vanadium in alluvial rice soil of Western Sichuan Plain

中国季风区土壤~（137）Cs背景值研究

Soil ~ ( 137 ) cs background values in monsoon region of China

其中Cr、Co和Zn的均值含量明显超出了陕西土壤背景值。

Where Cr , Co and Zn were significantly exceed the mean soil background value in Shaanxi Province .

GM（1,1）背景值重构模型在体育中的应用研究

The Application Research of the Reconstructed GM ( 1,1 ) Model of Background Value in Sports

其它重金属中Pb含量较高，接近于国家标准背景值。

The content of Pb is higher , close to the background value of the national standards .

GM（1,1）模型的背景值构造方法和应用（Ⅰ）

The Structure Method and Application of Background Value in Grey System GM ( 1,1 ) Model (ⅰ)

背景值是影响灰色模型预测精度的关键性因素之一，GM（1,1）改进模型是在对背景值进行优化的基础上建立的灰色模型。

The background value is one of key factors for influence the monitoring precision of gray model .

确定~（137）Cs背景值所需的采样点数与采样面积

Sampling numbers and area for the confirmation of ~ ( 137 ) cs reference inventory

西秦岭泥盆系Au背景值的确定、元素地球化学特征及地质意义

Determination of the Au background value and Au geochemistry in the Devonian of the West Qinling and their geological significance

正常动态背景值预估的门限反馈（MF）模型及使用效果

Threshold feedback ( mf ) model for predicting normal dynamic background value and its efficiency

利用对数正态分布图获得了Pb、Cu、Zn、V、Se和Ti等元素的地球化学背景值。

The geochemical background levels are obtained by applying lognormal distribution plots to Pb , Cu , Zn , V , Se and Ti .

同时，该算法优化GM（1,1）预测模型的背景值，提高了预测精度。

Meanwhile , the optimized background value of GM ( 1,1 ) prediction model is adopted to improve the prediction precision of this algorithm .

土壤和沉积物中多数重金属元素尚未超过自然背景值，只有沉积物中Cd和Pb，土壤中的Cu、Cd和Hg超过。

Most of heavy metals do not exceed the natural background level except Cd and Pb in sediments and Cu , Cd , Hg in soils .

异常下限为30×10-9，是Au低背景值区。

The minimum value of the anomaly is 3 0 × 10 - 9 , belonging to the low background value area of Au .

除As外的其他重金属含量都高于土壤背景值，Cd、Hg、Cr、Pb存在着严重的点源污染，整个昆山市农用地土壤重金属污染区域差异比较明显。

Serious point pollution exists in Cd , Hg , Cr and Pb . Regional diversity of agro-land soil heavy metal pollution in Kunshan is relatively obvious .

该模型由背景值构造、加权GM（1,1）模型和神经网络补偿器三部分组成。

The model is composed of three parts , that is : structuring method of background value , weighted grey model and neural network based error compensator .

南宁市郊菜园土壤除Cr外，Cu、Zn、Cd、Pb、Ni的平均值均高于南宁市土壤背景值。

The average contents of QK Zn Cd Pb Ni except Cr in Nanning city suburbs ' vegetable garden soils were higher than the background values of Nanning city soils .

确定土壤背景值的Hazen概率法&以铜陵矿区Pb为例

Hazen probability curve method for determining background content of soil-A case study of Pb element in Tongling area

通过对212块马兰黄土样品的分析，获得了其微量元素Zn、Cu、Mn、Co、Ni的常见含量范围和自然背景值。

212 samples of the MaLan loess were chemically analyzed for the normal and natu-ral background values of the trace elements Zn . Cu , Mn , Co , and Ni .

引入向量θ得背景值序列的精确计算式，将GM（1,1）模型推广为GM（1,1，θ）模型。

The vector θ was introduced into the accurate calculation formula of background value array , and GM ( 1,1 ) was consequently generalized into GM ( 1,1 ,θ) .

GM（1,1）模型是有偏差的灰指数模型，其精度取决于背景值的构造形式和初始条件的选取。

As a gray exponential model with distortions , the precision of GM ( 1,1 ) depends on the conformation of background value and the selection of original condition .

除Cd、Cr和Pb略低于背景值外，其他重金属均高于其背景值，其中以As污染指数和超标率最高。

Apart from Cd , Cr and Pb , all the other soil heavy metals exceeded their background levels in concentration , and As ranked first in contamination index and over limit rate .

主要结论如下：（1）同区域背景值相比，研究点的植物生长介质中Cu、Zn、As、Cd等元素含量超标严重。

Leading conclusions : ( 1 ) In comparison with background level , the content of the corresponding heavy metals is higher in the corresponding inedible plants , and is lower in the edible crop .

灰色GM（1,1）模型中的背景值构造法是影响模型适应性和精度的关键因素。

The structure method of background value in grey system GM ( 1,1 ) model is considered to have an important influence on the adaptability and precision of GM ( 1,1 ) model .

IGM（1,1）避开了灰微分方程参数辨识时的合理选取背景值的问题，实现GM（1,1）模型的直接建模。

IGM ( 1,1 ) avoids the problem how to rationally select background values in parameter identification of grey differential equation and realize the direct modeling of GM ( 1,1 ) .

它所含有的重金属Cu，Cd，Ph，Zn的含量均大为超过上海市农业土壤背景值和JENSEN底泥污染评价值。

The contents of heavy metals such as Cu , Cd , Pb and Zn are more greatly than the background level of Shanghai agricultural soils , and JENSEN pollution evaluation value for sediments .

结果表明：源于氯碱厂Hg污染的五里河沉积物中Hg，Pb，Zn含量平均值分别超过区域沉积物背景值662,2.21,4.51倍；

The Hg , Pb , Zn average contents in sediment of Wuli River which was contaminated by chlor-alkali were 663,3.21, 5.51 times as high as the regional sediment background value , respectively .