不同类型甘薯品种块根淀粉粒粒度的分布特征

 【目的】阐明不同类型甘薯块根淀粉粒粒度的分布特征及其与淀粉品质的关系。【方法】选用6个淀粉型品种、5个食用型品种和1个兼用型品种,研究块根中淀粉粒的体积和数目分布、淀粉粒体积和数目分布与淀粉及其组分含量的相关性。【结果】甘薯块根含有小（粒径＜3.36 µm）、中（粒径3.36—19.76 µm）和大（粒径＞19.76 µm）3种类型淀粉粒,其粒径范围为0.39—55.14 µm。淀粉粒体积和数目都表现为双峰分布,低谷粒径均为3.36 µm;其中,粒径＜3.36 µm的淀粉粒体积占总体积的9.8%—18.5%,而粒径＜3.36 µm的淀粉粒数目占总数目的97.7%—99.1%。与淀粉型品种相比,食用型品种粒径＜3.36 µm的淀粉粒所占体积百分比和粒径＜1.00 µm的淀粉粒所占数目百分比较高。块根总淀粉、直链淀粉和支链淀粉含量与小型和中型淀粉粒的体积百分比呈显著负相关,与大型淀粉粒的体积百分比呈显著正相关;支/直链淀粉比率与小型和中型淀粉粒的体积百分比呈显著正相关,与大型淀粉粒的体积百分比呈显著负相关。【结论】食用型甘薯块根中小型淀粉粒所占比例较高,而淀粉型甘薯块根中大型淀粉粒所占比例较高。     

Investigations of the particle motion characteristics in the gas solid two phase wake of leeward side circular cylinder

This paper investigates the characteristics of the particle motion in circular cylinder wake flow of leeward side by simulating the micro particle flow around circular cylinder using Euler two fluid model combined with Reynolds stress model. It compares the particle velocity and concentration of different particle size in the leeward area. The results show that the vortex is formed after the gas flowed passing the cylinder, and the concentration and velocity of particles are affected by the turbulent intensity in the leeward side. Gas entrainment vortex and particles own inertia decide the flow form of fine particle around the cylinder. Both effects impact the particle concentration distribution of different size particles in the leeward area. With the increase of particle size, the particle concentration increases at the beginning and then decreases in the leeward area.     

Affine invariant shape recognition with particle swarmoptimization algorithm

Focusing on the problem that affine transformation will exist among the contour images due to variation of the viewpoints, a new approach to extract affine invariant features and matching strategy is proposed for shape recognition. First, the centroid distance and azimuth angle of each boundary point are computed. Then, with a prior defined angle interval, all the points in the neighbor region of the sample point are considered to calculate the average distance for eliminating noise. After that, the centroid distance ratios(CDRs) of any two contour points with angle difference of 180° are achieved as the representation of the shape, which would be invariant to affine transformation. Since the angles of contour points changed non linearly among affine related images, the CDRs should be resampled to build corresponding relationship. It could be regarded as an optimization problem of path planning. In our method, a PSO based path planning model is presented to address this problem. The experimental results demonstrate the efficiency of the proposed method in shape recognition with translation, scaling, rotation, distortion and noise interference.     

吉林省低山丘陵区水土保持措施对土壤颗粒组成和速效养分影响分析

通过对吉林省低山丘陵区水土保持措施对土壤颗粒组成和速效养分的影响进行了分析,结果表明：目前水土保持措施下,生态修复措施是短时期内吉林省东部低山丘陵区进行土壤肥力恢复较好的措施。各措施粘粒含量均低于裸地;0-20cm土壤粘粒含量普遍低于20-40cm土壤粘粒含量,20-40cm土壤砂粒含量低于0-20cm土壤砂粒含量。各措施0~20 cm土层的速效养分含量总体上高于20~40 cm土层。水土保持措施对土壤氮素养分的修复效果要好于P、K。速效P与20-40cm的粘粒含量呈极显著负相关,其他均无显著相关性。为遏制黑土退化的趋势和保障生态安全,应结合当前国家需求,在进行水土流失综合治理的同时积极利用当地丰富的秸秆资源进行土壤培肥。     

沙地柏土壤特性与生物量的关系

对毛乌素沙地固定沙地不同地形（沙丘的顶部、迎风面、底部）中的沙地柏生物量进行比较,分析了土壤养分状况、土壤粒径与生物量关系。结果表明：迎风面的氮、有机质含量比较高,能够促进生物量的提高;天然沙地柏（土层深度〈50 cm）土壤颗粒组成均是以50-100μm的颗粒为主,生物量与土壤颗粒之间可相互影响。     

小茴香对小鼠免疫功能的影响

[目的]研究小茴香对环磷酰胺模型小鼠免疫功能的影响。[方法]以环磷酰胺制备小鼠免疫低下模型并结合体外药理试验,测定灌胃给药后小鼠体内巨噬细胞吞噬率、血清溶血素抗体水平,并观察植物血凝素诱导T淋巴细胞的增殖反应。采用含药血清体外培养小鼠腹腔巨噬细胞,MTT法考察巨噬细胞的活性,并观察体外培养的巨噬细胞吞噬红细胞的吞噬百分率和吞噬指数。[结果]小茴香提高免疫抑制小鼠碳粒廓清率,促进血清溶血素形成以及促进T淋巴细胞增殖。[结论]小茴香有提高小鼠免疫功能的作用。     

蓖麻秆刨花板的最佳制板工艺参数

采用多因素多水平法,对100种不同工艺条件下制造的刨花板的性能进行研究,用于确定板材的最佳工艺参数。用主成分分析法对板材的综合性能进行研究,在充分考虑板材的生产效率、生产成本和性能稳定性的基础上确定出板材的最佳工艺：热压温度150℃,热压时间30s／mm,施胶量12％,热压压力3．5MPa;所制板材除吸水厚度膨胀率外,其他性能均可满足国标要求。     

橡胶粒子束缚水分的生理功能初析

橡胶粒子是由半单位生物膜包裹的细胞器,表面带负电荷,能够吸附水分子;由于在细胞中橡胶粒子数量极多,故能形成较强束缚水分的能力。产胶植物通过增加橡胶粒子合成,来提高吸水能力,以抵御逆境胁迫;胁迫消除时,又融合小橡胶粒子为更大粒子,来减少橡     

植物游离小孢子及其培养所获得的组织在遗传转化中的应用

植物游离小孢子及其培养所获得的组织是植物基因工程中优良的受体,它们具有单倍性和较高胚胎发生能力的特性。因此,以它们为受体构建遗传转化体系可以快速获得纯合的转基因植株。通过综述植物游离小孢子及其培养所获得的胚状体、愈伤组织作为转化受体在根癌农杆菌介导法、基因枪轰击法、激光微孔穿刺法、显微注射法、电激法、PEG介导法等转化技术中的应用研究进展,对目前游离小孢子作为转化受体存在的问题及发展前景进行了探讨。