Iron fortification and parboiled rice quality: appearance,cooking quality and sensory attributes

BACKGROUND: Iron (Fe) fortification of parboiled rice increases both Fe concentration and bioavailability in milled grains (i.e. white rice). The aim of the present study was to evaluate parboiled rice fortified with 250 and 450 mg Fe kg^?1 paddy rice for its pre‐cooking appearance, cooking quality, basic sensory attributes and overall acceptance in comparison with unfortified parboiled rice in Thailand and local parboiled rice in Bangladesh. RESULTS: Fe fortification at 250 mg Fe kg^?1 paddy rice significantly elevated Fe concentration in white rice to as high as 19.1 mg Fe kg^?1 white rice, compared with 6.2 mg Fe kg^?1 white rice for unfortified parboiled rice, without any adverse impact on consumer acceptance based on the current preliminary assessment. The added Fe was well retained in the cooked rice, with significant residual value for human intake. Panellists in Thailand and Bangladesh did not detect significant differences in the acceptability of parboiled rice fortified at 250 mg Fe kg^?1 paddy rice compared with unfortified and local parboiled rice respectively. However, Fe fortification of parboiled rice at the higher level of 450 mg Fe kg^?1 paddy rice significantly intensified the yellow colour of the grain and changed the off‐flavour, chewiness and flakiness of the cooked Fe‐fortified parboiled rice. This resulted in a low acceptability ranking of parboiled rice fortified at 450 mg Fe kg^?1 paddy rice by panellists in both Thailand and Bangladesh. CONCLUSION: Fe fortification of parboiled rice at an appropriate level (e.g. 250 mg Fe kg^?1 paddy rice) is dosage‐effective and acceptable to rice consumers. Consumer acceptability of Fe‐fortified parboiled rice is closely related to pre‐cooking appearance, cooking quality and sensory attributes. Copyright © 2009 Society of Chemical Industry     

Iron (Fe) bioavailability and the distribution of anti‐Fe nutrition biochemicals in the unpolished,polished grain and bran fraction of five rice genotypes

Iron (Fe) bioavailability in unpolished, polished grain and bran fraction of five rice genotypes with a range of Fe contents was measured by in vitro digestion and cultured Caco‐2 cells of cooked grain. There was a significant difference in Fe bioavailability among the five rice genotypes tested, in both the unpolished and polished grain. The range of Fe bioavailability variation in polished rice was much wider than that of unpolished, suggesting the importance of using Fe levels and bioavailability in polished rice grain as the basis for selecting high‐Fe rice cultivars for both agronomic and breeding purposes. Milling and polishing the grain to produce polished (or white) rice increased Fe bioavailability in all genotypes. Iron bioavailability in polished rice was high in the UBON2 and Nishiki, intermediate in both IR68144 and KDML105, and low in CMU122. All genotypes had low bioavailability of Fe in bran fraction compared to unpolished and polished grain, except in CMU122. CMU122 contained the lowest level of bioavailable Fe in unpolished and polished grain and bran, because of the dark purple pericarp colored grain and associated tannin content. The level of bioavailable Fe was not significantly correlated with grain Fe concentration or grain phytate levels among these five genotypes tested. The negative relationship between Fe bioavailability and the levels of total extractable phenol was only observed in unpolished (r = ?0.83**) and bran fraction (r = ?0.50*). The present results suggested that total extractable phenol and tannin contents could also contribute to lowering bioavailability of Fe in rice grain, in addition to phytate. Copyright © 2006 Society of Chemical Industry     

崩落法开采岩层移动影响因素的数值模拟

随着矿山开采深度的增加,岩体所处的力学条件变得复杂,采用崩落法开采的深部矿体岩层移动规律受多种因素影响且不同于浅部。离散元法是基于不连续性假设的数值方法,它特别适合于求解节理岩体中的非连续性问题。基于离散元理论,采用数值计算软件3DEC,分析了不同节理倾角、不同侧压力系数及不同开挖阶段对深部矿体崩落法开采过程中岩层移动规律的影响,研究结果表明：不同倾角的优势结构面对崩落发展趋势影响显著,水平节理对崩落发展有良好促进作用;侧压力系数越大,崩落高度越小;深部矿体开采过程中,由于承压拱的存在,开采高度为120 m时,并未引起大范围塌陷。研究结果可为深部矿体崩落法开采岩层移动规律及地表沉陷范围的确定提供一定的参考依据。     

基于BP神经网络的不同时间尺度泵站前池水位预测模型

针对建筑物调控下的水位预测难题,建立基于BP神经网络的泵站前池水位预测模型,在不同时间尺度下分析时间序列、影响因子、预报因子对水位预测精度的影响。将构建模型应用于胶东调水工程东宋泵站,研究结果表明：在数据总量一定的情况下,训练期和预测期之比为7∶3时,预测结果较好;数据量越大,保持一定预报精度所需要的正相关的影响因子数量越多;短时间内,预测时间间隔与数据本身时间间隔相同时,预测效果更好。该构建模型能够满足明渠调水工程泵站前池的水位动态预测需求,实现泵站前池水位的2 h准确预测和4 h一般准确预测,同时可在其他类似明渠调水工程中推广应用。     

基于竖缝隔板的大底坡鱼道水力优化数值模拟

为了优化大底坡竖缝式鱼道池室水力特性,在验证物理模型的基础上,构建三维水动力数学模型,考虑5种大底坡坡度对竖缝有无隔板及竖缝隔板不同安装高度的池室水力分布进行了数值模拟分析。结果表明,竖缝设置隔板能有效减小池室最大流速和平均湍动能;当底坡为1/20时,池室最大流速下降率为10.16%~14.84%,平均湍动能下降率为21.88%~42.19%,主流最大流速衰减率为61.24%~61.82%,池室内形成了小流速、低湍动的Ω形连续性水流;改变竖缝隔板安装高度会影响隔板上下水深处的竖缝流速大小,但对隔板上下水深处的流速、湍动能、应变率的分布规律无显著影响。     

PBT熔喷非织造布的接枝改性研究

研究了以高锰酸钾/硫酸(KMnO4/H2SO4)为引发剂,丙烯酰胺与PBT熔喷非织造布的接枝共聚反应。考察了溶胀剂甲苯浓度、高锰酸钾浓度、硫酸浓度、预引发温度、预引发时间、丙烯酰胺浓度、反应温度及时间等因素对接枝共聚反应的影响规律。结果表明:当溶胀剂甲苯浓度为2%、高锰酸钾浓度为1.5×10-3mol/L、硫酸浓度为0.3mol/L、预引发温度为60℃、预引发时间为60min、丙烯酰胺浓度为0.35mol/L、反应温度为60℃、反应时间为3.5h时,接枝效果最佳。     

大型电机线圈的再结晶退火工艺研究

大型同步电机磁极线圈在制造时,直角拐角处因压弯而产生冷作硬化现象,使铜带状线圈无法装压成型,直角拐角处的局部电阻率也因为加工变形而增大,使磁极线圈的技术尺寸无法保证,使用性能受到影响.通过对磁极线圈再结晶退火热处理工艺的试验研究,确定了热处理工艺方案,取得了满意的效果.     

低温制备Fe-TiO2及其可见光催化性能研究

采用大量水体系溶胶-凝胶方法在低温下制备了掺杂铁的二氧化钛纳米材料(Fe-TiO2),通过XRD、XPS、SEM、UV-Vis对样品进行了结构、形貌以及光化学方面的表征,研究了铁掺杂浓度对样品结构和性能的影响。结果表明,低温下合成的样品主要以锐钛矿型存在,结合有少量板钛矿型。掺杂1%的Fe-TiO2具有最大的吸收带红移,在室内具有最好的对甲基橙光催化性能。主要认为铁的掺杂抑制了电子和空穴的复合并且增强了其在可见光区的吸收。     

高度城市化地区生态空间规划管控研究——以深圳市为例

在空间规划体系改革的背景下,全域全要素统筹管理是未来国土空间规划领域必须完善的范畴,生态空间作为国土空间的重要组成部分,其规划的作用和地位将越来越重要.本文在总结相关研究和实践的基础上,以深圳市为例,提出高度城市化地区生态空间的规划管控体系构建建议,并重点对规划体系的构成与内容、管控单元划定和管控方式等方面进行研究,以期为同类区域的国土空间规划体系构建提供借鉴.     

Scalable Fabrication of Stable High Efficiency Perovskite Solar Cells and Modules Utilizing Room Temperature Sputtered SnO2 Electron Transport Layer

Stability and scalability have become the two main challenges for perovskite solar cells (PSCs) with the research focus in the field advancing toward commercialization. One of the prerequisites to solve these challenges is to develop a cost‐effective, uniform, and high quality electron transport layer that is compatible with stable PSCs. Sputtering deposition is widely employed for large area deposition of high quality thin films in the industry. Here the composition, structure, and electronic properties of room temperature sputtered SnO₂ are systematically studied. Ar and O₂ are used as the sputtering and reactive gas, respectively, and it is found that a highly oxidizing environment is essential for the formation of high quality SnO₂ films. With the optimized structure, SnO₂ films with high quality have been prepared. It is demonstrated that PSCs based on the sputtered SnO₂ electron transport layer show an efficiency up to 20.2% (stabilized power output of 19.8%) and a T₈₀ operational lifetime of 625 h. Furthermore, the uniform and thin sputtered SnO₂ film with high conductivity is promising for large area solar modules, which show efficiencies over 12% with an aperture area of 22.8 cm² fabricated on 5 × 5 cm² substrates (geometry fill factor = 91%), and a T₈₀ operational lifetime of 515 h.