北欧4种燕麦在果洛地区的引种栽培试验

在果洛拉加乡黄河谷地及西哈垄沟内,对引进的４种北欧燕麦进行的引种栽培试验结果表明：４种燕麦中ＹＴＡ较早熟,全生育天数１０４天;ＬＥＮＡ干草产量最高（４２３９９ｋｇ／ｈｍ２）;ＭＥＬＹＳ从籽实产量、茎叶比、营养成份等综合性状评价,都优于其它品种;ＮＥＯＮ的饲草品质最为优秀     

Harvesting machine for kelp culture in floating raft

Kelp is not only a kind of food of sea vegetable for human, but also widely used as raw materials in processing food, chemical engineering, pharmaceutical and cosmetic industries. In China kelp is generally planted on floating raft by using horizontal kelp rope cultivation method and often harvested manually. Harvesting kelp by hand is a difficult process with low production efficiency and high labor intensity. In this paper, a harvesting machine was developed for floating raft culture of kelp. It consists of mainly two locomotion modules, a collection/transmission module and a power module. The structure and working mechanism of this machine was presented and analyzed in detail. The tests of experiments were conducted as well with the developed machine. The manual harvest efficiency is 16.7%; however the mechanized harvest efficiency average value is 35.8%. The harvest time could be reduced by half if the company takes the same people to work. It is proven that the design of the machine is feasible.     

The long‐term fertilization experiments in Halle (Saale), Germany — Introduction and survey

Six of originally eight long‐term trials in Halle (Saale), Germany, are still continuing. Five are situated at Julius‐Kühn‐Feld, an experimental station launched by Julius Kühn in Halle in 1866. Apart from the Eternal Rye trial established in 1878, those are phosphorus, potassium, lime, and organic fertilization long‐term trials, all being launched by Karl Schmalfuß in 1949. Other long‐term trials have been terminated, but data are available on the effects of nitrogen fertilization and the physiological reaction of fertilizers. Another long‐term trial in Halle (Adam‐Kuckhoff‐Straße 17b) investigates the influence of fertilization on soil formation from loess. Up to now, the major results are as follows: 1. Changes in soil‐ecological properties due to fertilization and rotation were only evident after 30 years, and new steady states sometimes took 70 years to occur. 2. In the long term, the C‐ and N‐contents of the soil largely depend on the amount of hardly decomposable organic matter applied with organic fertilization. High mineral‐N doses, with consequent high crop and root residues, increased the humus content of the soil. 3. Mineral fertilization can replace organic fertilization in terms of sustainable yield capacity provided equal nutrient amounts were applied. 4. The high P‐supply ability of the soil in Halle could not be explained by traditional soil analysis methods of calculating plant‐available P. With some restrictions, the same is valid for K. 5. At the experimental site, soluble salts (nitrate, sulphate) accumulated in the subsoil. 6. A regular lime demand of central German chernozems could be proved, especially in case of low soil organic matter (SOM) and physiologically acid fertilization.     

Dispersion and migration of fine particles in two palygorskite‐containing soils of the Jordan Valley

Migration of different mineral particles within columns of soil‐sand mixtures containing 10 or 20 mass % of soil was investigated by establishing differences in the mineral suite between the ”︁bulk clay” and the ”︁mobile fine material” fractions. The ”︁bulk clay” fractions of all soils contained smectite, palygorskite, kaolinite, quartz, feldspar, and calcite. The soils were saturated with sodium by leaching with NaCl solution, and then leached with distilled water. Clay dispersion and particle migration occurred in the columns. Values of SAR (sodium adsorption ratio) of the effluent decreased with time due to carbonate dissolution. At a certain SAR value, the clays apparently formed aggregates, and as a consequence particle migration stopped in the column. In addition to clay‐sized particles (< 2 μm), very‐fine‐silt‐sized particles (2— 5 μm) were able to migrate in the soil‐sand mixtures, too, and to some extent fine‐silt‐sized particles (5—10 μm) as well. Average size of mobile particles decreases with increase of soil content in the soil‐sand mixtures. The mineralogical composition of the ”︁mobile fine material” changed during the experiment. At the beginning of the experiment, the ”︁mobile fine material” was enriched in the non‐phyllosilicates (especially in calcite, and in some cases in quartz, feldspar and dolomite) and contained low concentrations of phyllosilicates (smectite, palygorskite and kaolinite). At the end of the experiment, the proportion of non‐phyllosilicates decreased, and as a consequence, the proportion of phyllosilicates increased. Among the non‐phyllosilicates, calcite was the most mobile mineral. Among the phyllosilicates, palygorskite was preferentially mobilized in topsoil horizons. In subsoil horizons, on the other hand, kaolinite was preferentially mobilized. This difference was explained by the different nature of carbonates in the topsoil and subsoil horizons. Palygorskite is preferentially occluded within the soil carbonates of lacustrine origin over smectite and kaolinite. These carbonates are present mainly in the subsoil horizons. As a consequence, the presence of these carbonates in the subsoil horizons decreases the migration of mainly palygorskite.     

窝眼窄缝式气吸滚筒排种装置的试验

为了实现超级稻工厂化育秧,保证作业质量,研制了窝眼窄缝式气吸滚筒排种试验装置。以超级稻“培杂泰丰”为研究对象,采用4因素3水平正交试验设计方法,研究了窝眼半径、窄缝宽度、真空度和滚筒转速对播种空穴率、重播率和合格率的影响规律。通过对试验结果的分析,得出了影响空穴率和合格率的主次顺序为窝眼半径＞真空度＞滚筒转速＞窄缝宽度;影响重播率的主次顺序为窝眼半径＞滚筒转速＞窄缝宽度＞真空度;最佳参数组合为窝眼半径5.5 mm、真空度4 kPa、滚筒转速为0.82 rad/s和窄缝宽度1 mm。经验证,在最佳参数下,播     

低比转速离心泵内部流场分析及试验

为了研究低比转速离心泵内部流动特性,对10种不同设计方案的低比转速离心泵进行了数值模拟和性能预测,讨论了叶轮和蜗壳的关键几何参数对内部流场和外特性的影响,分析了不同设计方案下泵内的静压、流线、速度和湍动能等分布,并针对复合式叶轮短叶片的分布位置和蜗壳喉部面积进行了对比试验。试验结果表明,该文优选的方案D,通过增加偏置短叶片后,扬程提高了5.5 m,效率提高了3.23%;增大蜗壳内部和喉部面积后,5种设计方案的额定点扬程均提高了约10 m,效率提高了约5%,且扩大了高效区范围。该研究将为低比转速离心泵的性能     

不同灭酶处理对燕麦气味和品质的影响

为选择合适的灭酶处理方法,通过电子鼻、感官评价和快速黏度分析等方法,对5种灭酶处理（焙炒、常压蒸煮、高压蒸煮、远红外处理和微波加热）对燕麦粉的气味、色泽和糊化特性的影响进行了研究。研究表明：燕麦粉的电子鼻主成分分析（PCA）二维和三维指纹图谱均可将不同灭酶处理的样品明显区分开来;样品的感官评价气味值由高到低依次为：焙炒组,红外组,高压蒸煮组,常压蒸煮组,微波组;样品白度检测结果由高到低依次为：红外组,微波组,焙炒组,蒸煮组,与色泽的感官评价结果基本一致,微波组和红外组的色泽明显优于其他3组的色泽。样品的糊化特性指标中,除糊化温度外,其他6项快速黏度分析（RVA）特征值均差异显著。由此说明,不同灭酶处理对燕麦粉的气味、色泽和糊化特性均有不同影响,应结合燕麦粉的不同用途选用不同的灭酶处理。     

农药新剂型——微乳粒剂配制的可行性研究

以三唑磷为模式农药,研究了一种外观为颗粒状、用水稀释后成微乳液的农药新剂型——微乳粒剂配制的可行性。以乳状液的中位径(D50)为因变量,各表面活性剂用量为自变量,采用混料均匀试验设计并结合偏最小二乘回归法筛选表面活性剂品种;用比例法与对分法优化各表面活性剂用量;采用旋转挤压造粒法造粒。将筛选获得的农乳500与农乳602号用于配制15%三唑磷微乳粒剂,其乳状液外观为淡蓝色透明状,分散相颗粒迁移速度为0,且不同水质(水硬度:0~3 420 mg/L,水温:10~50 ℃)下乳液稳定性均合格;乳状液D50为54.2 nm,粒径分布范围为15.7~122 nm,粒径增大速率为0.01%/min;乳状液在相对离心力10 730×g下离心5 min未发生相分离。结果表明:该三唑磷微乳粒剂的乳状液为微乳液,微乳粒剂可以成功配制。     

Measurement and simulation of herbicide transport in macroporous soils

Lysimeter experiments were carried out to study pesticide transport through macroporous soils. In order to differentiate between the effects of soil structure and chemical behaviour, the leaching experiments were conducted using disturbed and undisturbed soil samples. Two herbicides with different sorption behaviours, and bromide as tracer were applied. The results were used to validate a dynamic simulation model which considers bypass flow in macropores. The simulation results show that the model is able to reproduce the soil suction within the soil as well as the spatial distribution of bromide and the herbicides. The continuity of the macropores is most important for the efficiency of bypass flow. The results indicate that cultivation practices like ploughing significantly influence the temporal and spatial distribution of the macropores. © 1998 SCI.