Porosity and capillarity of weft knitted spacer structures

A geometrical model of weft knitted spacer structures made with mono-filament yarn has been analysed to understand the spacer yarn path. Theoretical models have been created to predict the porosity and the radius of the capillaries of a knitted spacer structure depending on their geometrical parameters, such as course spacing, wale spacing, stitch length, fabric thickness, count of yarn and fibre density. Polyester knitted spacer fabrics were produced with different parameters; their porosity was determined by measuring the weight and compared with the theoretical porosity. The validity of the model was confirmed by experimental results. The porosity of knitted spacer structures made out of mono-filament yarn can be maintained above a certain level by adjusting the fabric parameters such as fabric thickness, course spacing and wale spacing.     

Effects of water application intensity, drop size and water application amount on the characteristics of topsoil pores under sprinkler irrigation

Field experiments were carried out to study the effects of sprinkler irrigation on the characteristics of topsoil pores. Total soil porosity, capillary porosity, air-space porosity and porosities of different pore shapes were analyzed using images analysis of thin sections of soil samples. The experimental treatments included five water application intensities (5.3, 7.7, 11.0, 15.0 and 20.7 mm/h), five drop diameters (0.76, 1.28, 1.92, 3.18, 4.19 mm) and five water application amounts (9.0, 23.6, 37.5, 49.6, 59.4 mm). The compounding sprinkler system was used in the experiments of water application intensity and single sprinkler was used in the experiments of drop size and water application amount. The total porosity, air-space porosity and porosities of elongated pores have the similar decreasing tendency and pattern when water application intensity, drop diameter or water application amount increase. Capillary porosity, porosities of round and irregular pores have no obvious changing tendency. The decreasing porosities of the elongated pores and macropores are the main reasons for the decreasing of total porosity under sprinkler irrigation. To maintain soil structure in good conditions, the reasonable parameters would be considered for water application intensity, drop diameter and water application amount.     

多种小麦蛋白质酸性聚丙烯酰胺凝胶电泳方法研究

研究了离子强度、缓冲液 p H、慢离子浓度、凝胶浓度等因素对小麦蛋白质 APAGE分离效果的影响 ,采用 L1 6 ( 41× 2 1 2 )正交试验进行了条件优化 ,所建立的甲酸盐 APAGE方法 ,具有分辩率高、重复性好的特点 ,可通过改变凝胶浓度实现不同蛋白的分离研究。因而此法在小麦蛋白分离、遗传研究、品种鉴定等方面具有广阔的应用前景     

林芝猪血液蛋白多型性研究

采用水平板淀粉凝胶电泳法检测了林芝猪19个血液蛋白座位的多型性,计算了基因频率及其估计误差以及估计值的可靠性和精确度,结果表明：林芝猪在Pa,Tf,Am,Hp,6PGD,CEs,Ca,Cp8个座位表现多型,分别由2,3,4,4,3,3,2,3个等位基因支配,其中CEs^c和Cp^x基因为首次发现。     

Numerical analysis of soil water dynamics in a soil column with an artificial capillary barrier growing leaf vegetables

An artificial capillary barrier (CB ), which consists of two layers of gravel and coarse sand, was used to improve the soil water retention capacity of the root zone of sandy soil for the cultivation of Japanese spinach (Brassica rapa var. perviridis ). The performance of a CB under specific conditions can be evaluated using numerical simulations. However, there have been relatively few numerical studies analyzing soil water dynamics in CB systems during crop growth. The objectives of this study were (i) to evaluate the performance of a CB during the cultivation of Japanese spinach irrigated at different rates and (ii) to investigate the effect of the irrigation schedule on root water uptake. Numerical analysis was performed using HYDRUS ‐1D after the soil hydraulic properties of the CB materials were determined. In most cases, the HYDRUS ‐1D results agreed well with the experimental soil water content data without any calibration when the dual‐porosity model describing soil hydraulic properties was used for gravel and coarse sand. We found that the dual‐porosity model was able to attenuate the unrealistically steep reduction in the unsaturated hydraulic conductivity predicted by the single‐porosity model. The numerical simulations also showed that the CB played an important role in maintaining plant‐available water in the root zone while maximizing the water use efficiency. The numerical simulations revealed that the irrigation frequency could be reduced by half during the early growth stage, and the water use efficiency could be greatly improved with the CB layer installed.     

高原型牦牛乳蛋白的多态性

采用聚丙烯酰胺凝胶电泳法对 119头高原型牦牛 4种乳蛋白的多态性特征进行了研究。结果发现只有αs1 CN基因座存在αs1 CNB,αs1 CNC和αs1 CNE,三个共显性等位基因而表现出多态性。乳蛋白的多态性基因座比例为 2 5 %。在乳蛋白方面 ,高原型牦牛与环湖型牦牛的遗传距离很小 (5 .3 6× 10 - 5)。     

Simple and Rapid Laboratory Method for Rewetting Dry Soil for Incubations

Soil microbial activity is greatly affected by soil water content. Determining the appropriate moisture content to rewet soils that have been dried in preparation for laboratory incubations to determine microbial activity can be laborious and time-consuming. The most common methods used achieve sufficient moisture content for peak microbial respiration are gravimetric water content, soil matric potential, or percentage of water-filled pore space (WFPS). Alternatively, a fast, simple, and accurate way to ensure that a given soil receives the appropriate amount of water for peak soil microbial respiration is to rely on natural capillary action for rewetting the dry soil. The capillary method is related to the gravimetric method for water uptake and has a strong correlation with WFPS. A microbial respiration test was conducted to compare rewetting methods. The 24-h carbon dioxide (CO₂) / carbon (C) results were very similar and strongly correlated using the gravimetric method and the capillary method for rewetting dried soil.     

利用SRAP建立快速鉴定高温平菇菌株的SCAR标记

为建立一套快速鉴定高温平菇的方法，采用SRAP标记技术对来自全国的16个高温平菇主要栽培菌株进行DNA指纹分析，初步构建其标准化DNA指纹图谱；在SRAP-PCR指纹图谱的基础上，将命名为高温灰平、高平侧5、高平678的3个栽培菌株的特异性DNA带转化为可以直接用于菌株快速鉴定的SCAR标记。研究结果表明，我国高温平菇栽培菌株遗传背景差异不大，存在同物异名的现象，而采用SRAP指纹及其SCAR标记鉴定高温平菇栽培菌株具有重要意义。     

泡桐丛枝病发生相关蛋白质的电泳分析

对毛泡桐和白花泡桐同龄同方位的病株健叶，病株病叶和健株健叶蛋白质进行了单向和双向SDS聚丙烯酰胺凝胶电泳分析研究。单向电泳结果表明，毛泡桐和白花泡桐病株健叶，病株病叶和健株健叶的蛋白质在种类和数量上存在一定的差异。其明显的蛋白质凝胶扫描谱带分别有22、20和17以及27、21和22条；双向电泳结果表明，毛泡桐与白花泡桐在健株健叶，病株健叶和病株病叶蛋白质变化方面具有一定相似性，即在两种泡桐健株健叶和病株健叶中存在的一种pI6.8,MW24KD蛋白多肽在病株病叶中观察不到。我们认为这种情形可能与发生泡桐丛枝病有一定的关系。     

河南省21个小麦品种(系)高分子量麦谷蛋白亚基的电泳分析

用十二烷基硫酸钠－－聚丙烯酰胺凝胶电泳（SDS－PAGE）对河南省21个小麦新品种（系）麦谷蛋白高分子量（HMW）亚基构成、不同等位基因间亚基变异及出现频率进行了系统分析，并计算了品质得分。结果表明，河南省现有小麦新品种（系）的高分子量麦谷蛋白亚基构成中以2＋12亚基居多，5＋10亚基的品种数量较少，对今后河南省小麦品质改良提出了建议。