自相似集分离条件和诸条件之间的关系

分形几何中计算自相似集的Hausdorff维数是一个比较重要的基本问题,文章主要将分形几何中和自相似集相关的各类分离条件进行了系统的整理,并对它们之间的关系进行了讨论.     

甜玉米遗传育种研究进展

甜玉米是玉米的一种胚乳突变型，甜玉米根据乳熟期胚乳中糖分含量和WSP含量的多少分为普通甜玉米、超甜玉米和加强甜玉米，加强甜玉米又称超甜粘玉米。目前在甜玉米育种中常用的基因有sul、sh2、se、btl、bt2、ae、wx、du等，它们都与胚乳碳水化合物代谢有关。这些基因的单基因纯合或多基因互作都能引起胚乳中碳水化合物组成或含量的改变。目前，已定出了与甜玉米有关的主要胚乳突变基因在玉米染色体上的确切位置，而且对这些基因在胚乳碳水化合物合成途径中的作用也有了较深入的了解。     

Effect of high molecular weight glutenins and rye translocations on soft wheat flour cookie quality

The influence of high molecular weight glutenin subunits (HMW-GS) on wheat breadmaking quality has been extensively studied but the effect of different Glu-1 alleles on cookie quality is still poorly understood. This study was conducted to analyze the effect of HMW-GS composition and wheat-rye translocations on physicochemical flour properties and cookie quality of soft wheat flours. Alleles encoded at Glu-A1, Glu-B1 and Glu-D1 locus had a significant effect over physicochemical flour properties and solvent retention capacity (SRC) profile. The null allele for Glu-A1 locus presented the highest cookie factor observed (CF = 7.10), whereas 1BL/1RS and 1AL/1RS rye translocations had a negative influence on CF. The three cultivars that showed the highest CF (19, 44 and 47) had the following combination: Glu-A1 = null, Glu-B1 = 7 + 8, Glu-D1 = 2 + 12 and no secalins. Two prediction equations were developed to estimate soft wheat CF: one using the HMW-GS composition and the other using physicochemical flour parameters, where SRCsuc, SRC carb, water-soluble pentosans, damaged starch and protein turned out to be better CF predictors. This data suggests that grain protein allelic composition and physicochemical flour properties can be useful tools in breeding programs to select soft wheat of good cookie making quality.     

番茄果实采后硬度变化的理化解析

在20℃、RH95%条件下对‘Saturn’番茄果实硬度变化进行了物理和化学解析。结果表明,随贮藏天数的推移贯入抵抗和压缩抵抗下降较快,多聚半乳糖醛酸酶(PG)活性和纤维素酶活性变化较大,而果胶甲酯酶(PME)活性变化较小。果肉硬度下降与半纤维素的下降和水溶性果胶(WSP)的上升有密切关系。     

蜂胶醇提液和水提液对急性炎症动物模型的作用

通过蜂胶醇提液和水提液对小鼠毛细血管通透性、大鼠急性关节炎、大鼠急性胸膜炎影响的实验研究,探讨蜂胶对急性炎症的影响,检测蜂胶水提液的抗炎效果. 结果表明,蜂胶水提液和醇提液对急性炎症均有明显的抑制作用,但作用机理似乎有所不同. 提示蜂胶发挥抗炎作用的主要成分除了黄酮类化合物之外还存在其它水溶性物质.     

采收期、贮藏温度和贮藏时间对不同基因型甜玉米品质的影响

对不同采收期、不同贮藏温度和贮藏时间的超甜(sh_2)、普通甜(su_t)和加强甜(su_1se)玉米杂交种以及大田玉米杂交种的还原糖含量、蔗糖含量、水溶多糖(WSP)含量以及水分含量等进行分析发现,在甜玉米类型中 sh_2杂交种在各个采收期总糖含量都是最高,su_1se次之,su_1最低。但 su_1的 wsp 含量最高,su_1se 与之接近,sh_2最低,与普通玉米相同。以糖分和水分为根据,认为普通甜玉米的合适采收期为授粉后18～26天,积温为306.2℃～420.2℃,加强甜玉米可以适当放宽,但超甜玉米合适采收期应在授粉20天之后。三种甜玉米在28℃下贮藏,糖分和水分含量都迅速降低,但超甜玉米有较强的保鲜能力。在4℃条件下贮藏一周,普通甜玉米和加强甜玉米糖分含量只降低10%,超甜玉米虽然降低了25.8%,但含糖量还保持在35%以上,说明低温贮藏对保持甜玉米的优良品质是十分重要的。     

Simple filtration system improves efficiency of a hydropneumatic root elutriator

Abstract

Separating roots from soil is a laborious and costly process, but a commercially available hydropneumatic root elutriator can semi‐automate the job. Hydraulic and pneumatic systems elutriate the roots from the soil, while the electrical system controls the on/off functions of the hydraulic system. The extruded steel frame of the elutriator serves a dual purpose; structural support and transport of water and compressed air. Water is transported in the lower and air in the upper part of the hollow inner cavity of the extruded steel frame. They exit the frame into polyethylene tubes that extend to the base of the elutriator. After prolonged use, however, this design feature can become problematic because flow to the elutriator of either system can be blocked at the nozzle inlets with rust particles that originate from the steel frame's inner walls. The blockage increases sample processing time due to dismantling, clearing, and reassembling, which eventually degrades the elutriator. To resolve these problems a 40‐mesh (420 micron) in‐line stainless steel water filter and a 40‐micron in‐line bronze air filter were installed in the polyethylene tube lines between the extruded steel frame and the base of the elutriator. These filters were found to reduce nozzle blockage, thereby increasing sample processing efficiency by 10% and improving sample quality.     

灌浆期小麦籽粒水溶性戊聚糖含量、粘度的动态变化及其相互关系研究

选取豫麦50号、豫麦34号和河北8901三个河南省主栽小麦品种,研究了灌浆期小麦籽粒水溶性戊聚糖(WSP)含量、水溶性戊聚糖阿拉伯糖和木糖比值(Ara/Xyl)以及籽粒提取液粘度的动态变化,并分析了小麦籽粒WSP与籽粒提取液粘度之间的关系。结果表明,在籽粒发育过程中,WSP含量变幅为1.51%~5.91%,呈现先降后略升的变化趋势。Ara/Xyl比值和籽粒提取液粘度均表现先升后降的变化趋势。相关分析表明,籽粒提取液粘度与水溶性戊聚糖含量呈负相关关系,与Ara/Xyl比值呈正相关关系。在供试3个品种中,豫麦34号的粘度值和Ara/Xyl比值均高于其他2个品种。