检索结果-南通市图书馆

Mechanisms for the Movement of Fe,Mn,Cu and Zn to Plant Roots in Loessal Soil and Lou Soil

在线全文

学校读者我要写书评

暂无评论

Pedosphere 1996年第3期6卷 245-254页

作者： XUMINGGANG zhangyiping 等 DepartmentofSoilScienceandAgrochemistry NorthwesternAgriculturalUniversityYanglingShaanxi712100Chi

The pot experiments were conducted in the artificial climate laboratories to determine the relative importance of mass flow and diffusion in supplying ,Fe,Mn,Cu,and Zn to wheat,soybean and maize plants growing in loessal soil and lou *** was found that the calculated relative contribution of mass flow of iron,manganese,copper and zinc to plant uptake varied from 5% to more than 100%,depending on the crop species and soil types as well as plant growth stage,soil moisture,atmosphere humidity,*** results also showed that the major transportation mechanisms of these micronutrients in soil-root system varied with the crop and its growth,climate and soil,singnificantly,In general,mass flow was more important for Cu and Zn and diffusion was more significant for Fe and Mn at the seedling stage.

关键词：黄土 Lou土养分运动铁锰铜锌植物根系机制扩散作用

Column Holdup Formula of Soil Solute Transport

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Pedosphere 2000年第1期10卷 89-92页

作者： WANGYU zhangyiping DepartmentofResourcesandEnvironmentalSciences NorthwestScienceandTechnologyUniversityofAgricultureandFOrestryYanglingShaanxi712100China DepartmentofResourcesandEnvironmentalSciences NorthwestScienc

The shortcomings of the present two formulae for describing column holdup are analyzed and deductions are made to find a new formula. The column holdup, Hw, described by the new formula is dimensional, and related to soil solute transport kinesis and column physical properties. Compared with the other two column holdups, Hw is feasible to describe dimensional column holdup during solute transport process. The relationships between Hw and retardation factor, R, in different solute transport boundary conditions are established.

关键词： column holdup retardation factor soil solute transport

Calculation of Thermodynamic Parameters for Freundlichand Temkin Isotherm Models

在线全文

学校读者我要写书评

暂无评论

Pedosphere 1999年第4期9卷 319-322页

作者： ZHANGZENGQIANG zhangyiping 等 DepartmentofBasicScience NorthwesternAgriculturalUniversityYangling712100China DepartmentofResource

Derivation of the Freundlich and Temkin isotherm models from the kinetic adsorption/desorpt ion equations was carried out to calculate their thermodynamic equilibrium constants. The calculation formulae ofthree thermodynamic parameters, the standard molar Gibbs free energy change, the standard molar enthalpy change and the standard molar entropy change, of isothermal adsorption processes for Freundlich andTemkin isotherm models were deduced according to the relationship between the thermodynamic equilibriumconstats and the temperature.

关键词： Freundlich isothermal model Temdin isothermal model thermodynamic parameters

Quantitative Effect of Soil Texture Composition on Retardation Factor of K^+ Transport

在线全文

学校读者我要写书评

暂无评论

Pedosphere 2001年第4期11卷 377-382页

作者： WANGYU zhangyiping DepartmentofNaturalResourecsandEnvironmentalSciences NorthwestScienceandTechnologyUniversityofAgicultureandForestryYanglingShaanxi712100（China） DepartmentofNaturalResourecsandEnvironmentalSciences N

With six packed columns composed of < 1 μm and 5 μm～0.25 mm fractions from an Eum-Orthic An- throsol (Columns 1～6) and one column of the Eum-Orthic Anthrosol (Column 7), K～(+) transport experiments under the condition of saturated steady water flow were conducted to qualify the effects of soil texture com- position on the retardation factor (R) of K～(+) transport. The results showed that the retardation factor of K～ (+) transport in the tested soil columns greatly increased with increasing clay contents. In an attempt to use pedo-transfer function (PTF) approach in the solute transport study, a preliminary PTF was established through the six packed columns (Columns 1～6) with soil basic data including soil bulk density, volumet- ric water content and clay content to predict the retardation factor, and proved valid by the satisfactory prediction of R in Column 7.

关键词： pedo-transfer function retardation factor soil basic properties soil solute transport