Variation and correlation analysis of flavonoids and carotenoids in Korean pigmented rice (Oryza sativa L.) cultivars     

Kim JK  Lee SY  Chu SM  Lim SH  Suh SC  Lee YT  Cho HS  Ha SH 《Journal of agricultural and food chemistry》2010,58(24):12804-12809

Flavonoids and carotenoids of pigmented rice ( Oryza sativa L.), including five black cultivars and two red cultivars, from Korea were characterized to determine the diversity among the phytochemicals and to analyze the relationships among their contents. Black cultivars were higher in flavonoids and carotenoids than the red and white cultivars. The profiles of eight phytochemicals identified from the rice grains were subjected to principal component analysis (PCA) to evaluate the differences among cultivars. PCA could fully distinguish between these cultivars. The Heugjinjubyeo (BR-1) and Heugseolbyeo (BR-2) cultivars were separated from the others based on flavonoid and carotenoid concentrations. Flavonoid contents had a positive correlation with carotenoid contents among all rice grains. The BR-1 and BR-2 cultivars appear to be good candidates for future breeding programs because they have simultaneously high flavonoid and carotenoid contents.  相似文献   

土壤颗粒分布体积分形维数与数量分形维数之间的关系     

李毅  李敏  Si Bingcheng  贺缠生 《农业工程学报》2012,28(23):82-91

土壤的体积颗粒分布(PSD)可用于同时确定数量分形维数(DN)和体积分形维数(DV)。以往的试验和理论研究均未直接比较DV和DN的关系。为建立DV和DN的关系并分析其参数的敏感程度,在中国各地取了12种不同质地土壤,利用激光粒度仪进行了测定。提出了含3个参数Rupper(颗粒半径的上限),Ri(第i个半径)和Rlower(半径下限)的DV-DN理论关系,该关系可说明为什么DN可能大于3。在未调整的幂定律范围内(PLR),DV的幂定律半径为38.6～85.8μm,DN的幂定律半径为53.2～358μm,估算的DV值(2.18～2.69)比DN值(2.38～3.19)小。调整后的PLR比未调整的窄。在调整的PLRs范围内,估算的DV值变化范围为2.11～2.56,而DN变化范围为2.28～3.02。调整和未调整PLRs得出的DV和DN的差异说明,Rupper,Rlower,Ri和Rlower/Rupper均可能影响DV与DN关系,有必要进行参数的敏感性分析。进行敏感性分析可基于敏感系数(C)来鉴别DV-DN关系中各参数改变所引起的DV和DN相对变化,从而找出对该关系影响最大的参数。就不同情况下计算的C值而言,Rupper是影响DN值的最重要参数,小的Rupper值可能导致估算DN的准确度降低。PLR范围越大,DN的估算越准确。根据DV估算DN的相对误差的绝对值在12%范围内,说明得出的DV-DN理论关系是正确的。  相似文献   

基于运行工况的低水头水轮发电机不圆度分析     

李正贵  杨逢瑜  司国雷  王得红  邓育轩  马彪 《农业工程学报》2013,29(24):79-85

由于结构的特殊性,农村电网中低水头、小容量发电机在运行中圆度变化较大,影响着发电机的稳定性。为了改善该类型发电机运行品质,提高低水头水轮发电机可靠性,该文针对发电机运行参数进行数据分析、并进行理论解析方程及ANSYS仿真分析计算,对造成发电机不圆度机理进行研究,发现作用在低水头水轮发电机特殊结构上的不平衡重力及交变离心力导致发电机偏心,从而造成发电机不圆度增大。同时偏心引起的不平衡磁拉力对机组稳定性影响较大,反过来不平衡磁拉力又使发电机不圆度增大。依据该文研究结论提出了低水头、小容量发电机安全运行措施,经过实际运行考验,证实运行效果比较理想。该研究可为农村小水电发电机安全运行提供一种解决方法。  相似文献   

仿生敲击式山核桃破壳机的设计与试验   总被引：2，自引：2，他引：2  

丁冉  曹成茂  詹超  娄帅帅  孙偲 《农业工程学报》2017,33(3):257-264

针对目前国内山核桃破壳机实用机型少,破壳率较低,果仁损伤率较高等情况,提出了一种仿生敲击(即模仿人工加工山核桃的方式)破壳方式,研制一款仿生敲击式山核桃破壳机。根据山核桃的物料特性以及破壳时所需的各项力学特性参数,建立了破壳机构设计的数学模型。确定了敲击臂的结构尺寸,优化了凸轮结构,并最终得到了凸轮的实际轮廓曲线。该文阐述了破壳机的总体结构与性能,建立了整机的三维实体模型,并根据建模制造了样机。该样机通过现场试验,结果表明:山核桃的含水率为14.55%~16.35%,大小为直径18~22 mm(沿缝合线方向)时,破壳率为99.41%,果仁损伤率为6.25%,生产率为94.93 kg/h,满足生产要求。该研究丰富与完善了坚果类果实的破壳机理与方法,为含隔坚果类的破壳机具设计与开发提供系统的理论依据和应用基础。  相似文献   

工程车辆翻车事故中司机头部伤害与保护仿真     

司俊德  王国强  崔国华  王继新  张英爽 《农业工程学报》2010,26(13):67-70

为了研究司机的头部在碰撞中的机械响应特性,该文采用有限元三维实体建模技术,建立了成人头部碰撞模型。通过虚拟试验方法使用成人头部模型对驾驶室内饰进行冲击分析,比较不同厚度和密度的聚氨酯泡沫对人体头部损伤评价指标的影响。结果表明：头部损伤值（HIC(d)）随着泡沫厚度的增加而减小,随着密度的增大,呈现先减后增的二次抛物线趋势。在驾驶室内壁覆盖18 mm厚的聚氨酯泡沫材料可以降低翻车事故中二次碰撞对司机头部的损伤。  相似文献   

Zirconium-Modified Activated Sludge as a Low-Cost Adsorbent for Phosphate Removal in Aqueous Solution     

Jiahong Wang  Xinhao Tong  Si Wang 《Water, air, and soil pollution》2018,229(2):47

A highly effective zirconium-modified activated sludge (Zr(IV)-AS) adsorbent was prepared from activated sludge and applied to remove phosphate from aqueous solutions by batch and column experiments. Characterized results revealed that zirconium was successfully loaded onto the activated sludge (AS), and the specific surface area and pore volume were substantially improved after zirconium loading on the AS. Zr(IV)-AS exhibited a high adsorption affinity for phosphate and the maximum adsorption amount was 27.55 mg P·g^?1 at 25 °C. Adsorption isotherms of phosphate could be described by the Langmuir model, and the adsorption kinetics were well described by the pseudo-second-order model. Phosphate adsorption on Zr(IV)-AS increased monotonically with decreasing solution pH. The presence of SO₄^2? in water resulted in slightly decreased phosphate adsorption on the adsorbent even at a high concentration (25 mmol/L), and a greater influence of HCO₃^? on adsorption could be ascribed to the increased solution pH with the addition of the HCO₃^?. Column adsorption experimental results showed that the adsorbent has excellent phosphate adsorption properties and that the effluent can meet the requirement of phosphorus in the national wastewater discharge standard of China. Phosphate-saturated Zr(IV)-AS can be effectively desorbed in 0.1 mol L^?1 NaOH solution, and the regenerated adsorbent still possessed the high capacity. The adsorption between the adsorbent and the phosphate is due to the electrostatic interaction and anionic exchange at the surface of the Zr(IV)-AS. Furthermore, this approach provides a possibility of treating wastewater with waste and has the potential for industrial applications for the removal of phosphate from wastewater.  相似文献   

激光控制平地系统设计与试验分析   总被引：10，自引：3，他引：10  

刘刚  林建涵  司永胜  侯明亮  毛恩荣  汪懋华 《农业机械学报》2006,37(1):71-74

开发了用于农田平地的激光接收与控制装置、液压调节装置、平地铲等。利用该系统与Trimble公司的激光控制平地系统进行了平地对比试验。试验结果表明，该系统工作性能稳定，与国产中等功率拖拉机液压动力输出匹配较好。  相似文献   

黄瓜早期若干数量性状遗传研究   总被引：3，自引：1，他引：3  

尹维娜  司龙亭  赵飞  宋秋瑾  王普  张建军 《中国农学通报》2006,22(1):232-232

利用4个黄瓜亲本，按4×4双列杂交法配制16个组合，测定早期产量、单瓜重、瓜条长度、瓜条直径、瓜把长度、果皮颜色6个数量性状。试验根据Hayman双列杂交法进行遗传分析。结果表明：单瓜重、瓜条长度、瓜条直径、瓜把长度、果皮颜色性状符合“加性-显性”效应模型，以加性效应为主，早期产量性状还受到上位性效应的作用，但以显性效应为主，存在超显性。除早期产量和瓜条直径外，其余各性状的广义遗传力和狭义遗传力都很高，表明受环境影响较小，可在早代进行选择；早期产量和瓜条直径的狭义遗传力较小，以非加性效应为主。  相似文献   

利用重组自交系(RILs)群体进行质量数量性状的遗传分析遗传模型和小麦产量性状遗传   总被引：9，自引：0，他引：9  

李斯深  陈茂学  王洪刚 《作物学报》2001,27(6):896-904

本文提出了利用RILs群体进行质量数量性状分析的4个遗传模型及统计分析方法.其中,模型Ⅰ、Ⅱ、Ⅲ、Ⅳ分别表示性状受1对主基因、2对独立的主基因、2对AABB×aabb型连锁的主基因、2对AAbb×aaBB型连锁的主基因与微效基因共同控制.可估算出主基因的加性效应(dma,dmb)、互作效应(im)、遗传方差(σ2m)和连锁图距(R),以及微效基因  相似文献   

The significance of meandering channel morphology on the diversity and abundance of macroinvertebrates in a lowland river in Japan     

Daisuke Nakano  Futoshi Nakamura 《水产资源保护:海洋与淡水生态系统》2008,18(5):780-798

• 1. Many rivers and streams across the world have been channelized for various purposes. Channel cross‐sections of meandering rivers are asymmetrical and have cross‐sectional diversity in their physical environment; cross‐sections of a channelized river are typically trapezoidal and have little cross‐sectional diversity, both in physical and ecological conditions. Several programmes to restore stream meanders have been undertaken to improve river ecosystems degraded by channelization. However, the association between diversification in the physical environment due to meander restoration and the macroinvertebrate community structure is poorly known.
• 2. This study of a lowland river in Japan assessed how the cross‐sectional diversity of the physical environment changed with restoration of a meander in a channelized river, and how the macroinvertebrate communities responded to the changes in physical habitat variation. Comparisons were made between the macroinvertebrate communities of a channelized reach, the restored meandering reach, and a natural meandering reach.
• 3. Natural meandering and restored meandering reaches showed higher cross‐sectional diversity in physical variables and total taxon richness across a reach than did the channelized reach. Almost all taxa observed in the natural and restored meandering reaches were concentrated in the shallowest marginal habitats near the banks. Shear velocity increasing with water depth had a negative association with macroinvertebrate density and richness.
• 4. This study demonstrated that the shallow river bed along the inside of bends formed point bars that provided a highly stable substrate, a suitable habitat for macroinvertebrates in a lowland river. It is concluded that meander restoration could be an effective strategy for in‐stream habitat restoration in lowland meandering rivers.

Copyright © 2007 John Wiley & Sons, Ltd.  相似文献