大孔隙

In general, smaller grain size and greater angularity tend to increase the porosity while an increase in range of particle size tends to decrease porosity.

通常，颗粒越小曲率越大孔隙度越大，而当颗粒尺寸增大时孔隙度会减小。

The results show that there are two types of pore in the sintered alloy, i.e., one is coarsen pores with diameter more than 30μm, the other is thin pores with diameters less than 10μm. These two types of pore evolve from two voids in green compacts respectively.

研究结果表明：合金中的孔隙主要有2种类型，即粒径为30μm左右的大孔隙和粒径在10μm以下的小孔隙，这2种孔隙分别由生坯中的2种主要间隙在烧结过程中演变而成。

Because of the distribution of macropore exhibit fractal rule, fractal theory can be used to study the structure of macropore.

由于土壤大孔隙的分布呈现分形规律，因此可以采用分形理论研究土壤大孔隙结构。

Acne, Age Spots, Scars, Sun-Damaged Skin, Tattoos, White Spots, Semi Permanent Makeup, Hormonal Mask, Liver Spots, Large Pores, Hyperpigmentation, Pimples, Fine Lines, Freckling, Stretch Marks, Crow''s Feet, Flaky Skin, Lip Creases and More!

痤疮凹陷疤痕、高龄伤疤，太阳损皮，纹身、白斑点，半永久性化妆损害、荷尔蒙遮蔽、肝点、大孔隙、色素沉着、青春痘疤痕、缺乏弹力皮肤、污点，皮肤皱痕、唇襞等！

This paper took the paddy soil after saving-water irrigation as the object,which is from Taian town of Yangzhou city, selected microtomy to get undisturbed soil samples respectly between two periods(before irrigation and after harvest), built up the analytical technique of numerical picture system.It also set up the analysis index of macropore structure,such as the number of macropores N, the macroporosityφ,the area A, the perimeter P and so on. Meanwhile make analysis contrast about horizonal distribution among 4cm, 6cm and 8cm scanning areas, vertical differences per 2cm unit and contrast in time between different periods.

本文选取扬州市泰安镇节水灌溉后稻田土壤为研究对象，采用切片法取开灌前和收割后的原状土样，运用数字图像制备技术，获取大孔隙数目N、大孔隙度Φ、面积A、周长P等分析指标，对4cm、6cm和8cm扫描直径内大孔隙作水平向差异性分析，对2cm单位深度上作垂向差异性分析以及对两个不同时期作时间差异性分析。

The content included (1) characterizing macropres shapes;(2) obtaining the index to charaterizing soil macropore quantificationally through digitalizing and analysising the photo of soil section;(3) comparing the shapes of macropores among soils, which reasons were discussed;(4) studying the influence of the zonal diversity, soil depth and land utilization on macropore characeristics;(5) estimating the space variability of macropore in the microscale using spore variability index;(6) analysising the connectivity and sinuosity of macropore using preferential flow breakthrough curve;(7) discussing the feasibility of indicating the preferential flow degree using macroporosity and macropore perimeter.

系统划分了大孔隙类型；描述了大孔隙形态；通过对土壤切片图像数字化处理和分析，获得了描述大孔隙特征的两个基本指标：大孔隙度和周长，并对大孔隙进行了定量化地描述；比较了各土类之间大孔隙的形态差异，从土壤发生学的角度对其原因进行了分析；研究了地带性差异、土壤层次和土地利用方式对大孔隙特征的影响；阐明了小尺度范围大孔隙的空间分布特征；结合Br〓标记优先水流穿透曲线分析了大孔隙的连通性和弯曲性，探讨大孔隙形态指标评价大孔隙优先水流作用强弱的可行性。

Macropore characteristics of main type soil--krasnozem, crimson loam, phaeozem and brown loam was firstly studied using soil section photography on the horizontal and vertical profiles in order to farther investigate the preferential transportance of soil water and solute.

中文题名土壤大孔隙特征的研究副题名外文题名 Characterizing macropores in soil 论文作者刘伟导师区自清研究员学科专业土壤学研究领域\研究方向学位级别博士学位授予单位中国科学院沈阳应用生态研究所学位授予日期2001 论文页码总数165页关键词土壤物理土壤大孔隙馆藏号BSLW /2003 /S152 /2 本文应用双剖面土壤切片成像法结合土壤优先水流穿透曲线，首次研究了4种主要地带性土壤：红壤、赤红壤、黑土和棕壤的大孔隙特征。

The revetment is made up of many single permeable tetrahedrons,and has much gap,so the group of permeable tetrahedrons can be treat as the porous media with large porosity.

四面体透水框架群是由很多单个四面体框架抛投而成，具有很大的空隙，因而，可以将框架群看成由很多框架杆件和大的孔隙组成的大孔隙率多孔介质。

Determining the structure of macropore can better understand and predict the behavior of water and solutes in macroporous soil, and help to protect the environment of underground water.

确定土壤大孔隙结构，可以很好地理解和预测水及溶质在有大孔隙土壤中的运移，保护地下水环境。

Adopting ameliorated flat arrow-like opener, the machine can cut off the continuity of soil macropore flow; form a compact fertilizer strip on the base of ridge, which can decrease nitrogen leaching by macropore flow. The machine makes use of single-disk to form ridge on the fertilizer strip.

采用改进后的平底箭铲式施肥开沟器能够阻断土壤中大孔隙流的连续性，在垄底形成一致密的施肥带，减少了氮肥在土壤中随大孔隙流的淋溶迁移。

The concept of equivalent rotationally rigidity is offered and the formula of rotationally rigidity is obtained.

主要做了如下几个方面的工作：对伸臂位于顶部的单层框架—筒体模型进行分析，提出了等效转动约束的概念和转动约束刚度的表达式。

Male cats normally do not need aftercare with the exception of the night after the anesthetic.

男猫通常不需要善后除了晚上的麻醉。