FLUIDISED BED GRANULATION AND COATING: APPLICATIONS TO MATERIALS, AGRICULTURE AND BIOTECHNOLOGY

In this review, firstly fluidised bed granulation and coating as a concept is introduced and critically compared briefly with other similar techniques. The way in which different types of granules can be produced is then discussed and related to the balance or break-up forces and binding strengths. This basic concept is then linked to the conditions of atomisation of the liquid feed, to the different independent techniques for controlling break-up forces and to the effect of the properties of the material to be granulated. This section concludes with a consideration of binder selection, both underlying theories and practical selection. Finally, three applications of the technique are introduced in which particles of desired properties have been engineered. These are i) the production of tungsten carbide granules for cutting tools and specialist applications; ii) the coating of vegetable seeds with chemical and bio-control agents; and iii) the manufacture of selective adsorbent particles for use in bioproduct recovery. The article highlights the great versatility of the technique and how an understanding of it can be used to advantage to produce particles to meet a wide range of specifications.     

PIXE、SEM与切片技术相结合研究低能离子注入种子的浓度-深度分布

用质子激发X荧光分析和扫描电子显微镜与切片技术相结合对能量为 2 0 0keV的钒离子注入花生后的浓度 -深度分布进行了测定 ,注入剂量为 9× 10 16/cm2 。结果显示 ,钒离子注入花生后的浓度 -深度分布与离子注入金属、半导体中的分布有明显的差异 :离子的射程歧离很大 ,少数离子的射程延伸到很深的区域。这种分布特征可能与植物种子具有疏松的结构有关。     

Synthesis of thin alpha alumina platelets with a large aspect ratio

Since α-Al₂O₃ platelets with small thickness and large aspect ratio are needed in various applications, it is of great importance to control their morphology. In the present work, we successfully fabricated α-Al₂O₃ platelets with small average thickness below 100 nm and large average aspect ratio above 100 by molten-salt method, using Al₂(SO₄)₃ as the raw material, eutectic mixtures of Na₂SO₄ and K₂SO₄ as the molten salt as well as TiO₂ and SiO₂ as the co-dopants. The effects of calcination temperature, seeds amount and seeds morphology on the final morphology of α-Al₂O₃ platelets were investigated. The growth mechanism of the α-Al₂O₃ platelets in molten salt was also discussed. A new growth mechanism of α-Al₂O₃ platelets in molten salt has been proposed, which is different from previous mechanism but can explain the two different phenomena caused by seeds with different sizes and quantity.     

Environmental and Genetic Variation of Soybean Tocopherol Content Under Brazilian Growing Conditions

Information about the chemical composition of soybean cultivars (cvs) and environmental impact on their composition is important for processors and exporters to meet the demand of niche markets. Tocopherol composition (α, β, γ, δ, and total), was analyzed in seeds of 89 Brazilian soybean cultivars grown under fertile soil in Ponta Grossa, Paraná state, Brazil, in 2001. A large range of variability was observed: for α-tocopherol, 11 ppm (cv. Davis) to 191 ppm (cv. IPB-T); for β-tocopherol, 6 ppm (cv. IAC 1) to 64 ppm (cv. IPB-T); for γ-tocopherol, 304 ppm (BR62 Carla) to 1333 ppm (cv. Bienville); for δ-tocopherol, 174 ppm (cv. UFV 15) to 580 ppm (cv.IAS-5; and for total tocopherols, 561 ppm (cv. BRS62 Carla) to 1,983 ppm (cv. BR4-RC). For comparison of different growing locations, cv. MG/BR 46 Conquista was grown in 16 different locations of the Minas Gerais and Goiás states (Central Region, ca. 17° South latitude). Higher content of total tocopherol was found in Conquista, Uberaba, Sacramento, and Cerrado, while lower contents were observed in Alvorada, Iraí, and Uberlândia. In the South region (ca. 23° South latitude), the cultivar IAS 5, grown in 12 different locations of Paraná and São Paulo states, showed high total tocopherol content in Londrina, Pedrinhas, Ponta Grossa, and Nuporanga, and lower amounts in Cascavel, Pirassununga, Luiziana, and Morro Agudo. Tocopherol content in soybean seeds varied due to genetic differences as well as to the local environmental factors of different growing locations.     

南繁甜菜种子下代块根产量形成生理基础的研究

试验表明:甜菜露地越冬采种种子比北繁种子发芽势强,种子萌发出苗快,出苗率高,甜菜幼苗生长茁壮。由露地越冬采种种子生长出的甜菜比北繁种子的甜菜,在叶面积指数、光合势、净光合生产率、干物质生产及光能利用率等主要生理指标上有显著优势。     

油桐籽不同年份和含油率差异对其含油率NIR检测模型影响的研究

收集了2014和2015年的油桐籽样本,用偏最小二乘法(PLS)分别建立了单一年份、混合年份及单一年份不同含油率范围的油桐籽含油率近红外光谱(NIR)检测模型,并验证。结果显示单一年份模型对本年份样本有较好预测,而对另一单一年份样本的预测精度明显下降,而混合年份模型对各年份样本都有较好预测;同年份不同含油率范围样本所建模型,含油率范围大,则模型预测精度下降,但稳定性更好。利用竞争性自适应重加权(CARS)算法筛选出30个变量,并结合PLS对混合年份样本建模,既简化了模型,又提高了模型预测性能,验证集相关系数为0.929,均方根误差为1.765,相对标准偏差为3.31%。因此,建立油桐籽含油率NIR检测模型时,应收集不同年份、不同含油率范围样本,并结合特征波长,以建立预测精度更好、稳定可靠且适应范围广的检测模型。     

液相化学还原法制备片状银颗粒的影响因素及研究进展

片状银颗粒具有独特的电性能、光性能等优良性能,近年来,在各个领域引起了广泛的关注.液相化学还原法具有反应条件可控、利于量产的优势,被广泛用于片状银颗粒的制备中.本文首先介绍了在液相化学还原法中片状纳米银颗粒的生长机理,分析了各反应条件,例如pH值、晶种、表面活性剂、硝酸银浓度等对生成片状银颗粒的影响.综述了国内外利用液相化学还原法制备片状银颗粒的研究进展;针对研究中存在的一些问题,展望了下一步的研究方向.     

Vitamins B in grain and cereal–grain food,soy-products and seeds

The present study provides information about the concentrations of vitamins B (thiamine, riboflavin, pyridoxine and niacin) in cereal and soy-products, grain and seeds. The concentrations of vitamins were determined by microbiological analytical methods. The results demonstrated that there are great differences in vitamin B composition within varieties of the analysed products. Whole grain products and seeds, are better sources of the vitamin B group than technologically processed products, and therefore more nutritionally efficacious.     

不同烟草品种种子萌发特性研究

对4种类型26个烟草品种种子的萌发特性进行了研究.结果表明供试品种的种子萌发高峰是在48h内,萌发情况在前期相对稳定,且相对集中.各类型烟草品种间平均发芽率及标准差都有较大差异;各品种的种子累积发芽率皆可用Logistic曲线来描述,但品种间曲线的陡度和拐点却有所不同.