Probability density function: A tool for simultaneous monitoring of pore/solid roughness and moisture content

We present a novel approach to multiscale fractal image analysis for monitoring the dynamics of the soil pore/solid network roughness due to moisture content changes. Roughness of the gray-level probability density function (PDF) of subsequent images of the drying soil was expressed in terms of its Hurst exponent (H_PDF), which correlated significantly with the soil dielectric permittivity and gravimetric water content, as well as with micro-horizon depth and the temporal progress of drying. We documented an intermittent character of the water content dynamics, correlating with oscillations of the pore/solid interface roughness. Our technique of PDF roughness analysis of digital images, exemplified here for soil moisture monitoring, can be applied for monitoring the other complex systems, for instance plant growth in greenhouse.     

延边地区水田分等的数学模型

本文利用模糊数学和统计的方法，通过采集样本，建立了一个多元隶属函数，提出了一种延边地区水田分等的数学模型．本模型对于任一参评地块，只要将其各指标值标准化后代入所建立的函数，即可得知该地块的等级．该模型具有合理、简便的特点．     

狍被毛髓质指数在保温和保护功能上的适应性变化

应用显微测微尺，对狍肩部和前肢部的和立夏被毛进行髓质指数测算，差异显著性检验表明，狍被毛的髓质指数既显著的季节性差异。也存在身体部位差异，即躯干部冬毛的髓质变得极为发达、肢体部冬毛的髓质却显著变细。     

肉牛宰后成熟阶段与食用品质相关指标的分析

通过测定宰后牛肉在不同时间内不同部位小片化指数、剪切力的变化数值,采用相关的方法得出:成熟时间对超微结构的改变起重要作用,肉牛宰后成熟时间应在5～6 d,肉牛胴体各部位间剪切力存在显著差异。     

含临界耦合非线性项的奇异椭圆方程组的非平凡解

研究了有界区域上一类含Sobolev临界指数与奇异位势的带权椭圆方程组,通过Caffarelli-Kohn-Nirenberg不等式与精确的能量估计,并运用山路引理得到了这类方程组非平凡解的存在性.     

Suitability of tef varieties in mixed wheat flour bread matrices: A physico-chemical and nutritional approach

Wheat flour replacement from 0 to 40% by single tef flours from three Ethiopian varieties DZ-01-99 (brown grain tef), DZ-Cr-37 (white grain tef) and DZ-Cr-387 (Quncho, white grain tef) yielded a technologically viable ciabatta type composite bread with acceptable sensory properties and enhanced nutritional value, as compared to 100% refined wheat flour. Incorporation of tef flour from 30% to 40% imparted discreet negative effects in terms of decreased loaf volume and crumb resilience, and increase of crumb hardness in brown tef blended breads. Increment of crumb hardness on aging was in general much lower in tef blended breads compared to wheat bread counterparts, revealing slower firming kinetics, especially for brown tef blended breads. Blended breads with 40% white tef exhibited similar extent and variable rate of retrogradation kinetics along storage, while brown tef-blended breads retrograded slower but in higher extent than control wheat flour breads. Breads that contains 40% tef grain flour were found to contain five folds (DZ-01-99, DZ-Cr-387) to 10 folds (DZ-Cr-37) Fe, three folds Mn, twice Cu, Zn and Mg, and 1.5 times Ca, K, and P contents as compared to the contents found in 100% refined wheat grain flour breads. In addition, suitable dietary trends for lower rapidly digestible starch and starch digestion rate index were met from tef grain flour fortified breads.     

考虑混沌成分的混凝土坝混合-混沌预测模型

混凝土坝表现出复杂的非线性动力学特性。考虑混沌成分对测值序列整体数值特征的影响,是提高混凝土坝位移监控模型拟合和预测精度的关键问题之一。在对混凝土坝监测资料混沌分析的基础上,基于混凝土坝系统演化过程中的非线性动力学特性,组合应用最大Lyapunov指数、相空间重构等数值分析手段,探讨了考虑混沌成分的混凝土坝混合-混沌预测模型构建原理与算法。该模型重点依据的是最近一次位移突变后的监测资料,考虑的是突变后形成的相对稳定的混凝土坝动力系统特性,实例证明该模型对混凝土坝位移的实时监测和预警都有重要意义。     

某类本原不可幂定号有向图的基指数

为了进一步了解本原不可幂定号有向图的基的特点及有关性质,对一个特殊的本原不可幂定号有向图的基进行了研究.通过分析这个图的特点,此图含有三个圈,其中两个圈长相等.运用反证法并结合图中的本原指数、点指数、基指数、Frobenius集、可幂与不可幂及＂异圈对＂等相关定义及性质加以证明.假定圈长相等的两个圈的符号相同或不同,讨...     

昆明市耕地压力空间分布与粮食安全分析

介绍了研究区的社会经济状况、耕地资源与粮食生产概况,依据2006年昆明市耕地相关数据,采用比较研究方法,利用最小人均耕地面积及耕地压力指数模型,结合人均食物需求量300和400kg2种情况,计算分析了昆明市及各县（区）的最小人均耕地面积和耕地压力指数。结果表明,人均粮食需求量Gr为300kg时,昆明市人均耕地面积具有区域差异性,体现了不同空间的分布规律,呈现了明显而典型的径向分布特点,以昆明市区为中心处于全市最低,从市郊向四周递减;人均粮食需求量Gr为400kg时,在同样的消费水平条件下,昆明市各县耕地承受的压力不同,而驱动这种变化的因素也各不相同;人均粮食需求量Gr为300、400kg时,昆明市耕地压力指数都大于1,耕地资源压力巨大,各县（区）耕地压力指数存在大于1和小于2种情况,其原因各不相同。结合昆明市耕地、粮食的空间分布特点及产业发展状况,提出了盘活存量用地、统筹规划昆明市各县（区）的产业结构布局、合理配置耕地资源等对策建议。