Effects of coralline lime on nutrient uptake and yield of field-grown sweet corn and peanuts in Oxidic soils of Western Samoa

Effects of coralline lime on yield and nutrient uptake by sweet corn (Zea mays saccharata Sturt.) and peanut (Arachis hypogea) were studied at three locations in Western Samoa. Coarse (0-10 mm) coralline material containing 31.1% Ca and 1.67% Mg was used as lime. There were two modes of application: band and broadcast, and three rates: 6, 12 and 18 ton ha^–1. In the highest rainfall location, marketable yields were increased by 250% for peanut and 160% for sweet corn by liming at 6 ton ha^–1, relative to the unamended control. Peanut yield increases were associated with reduced Mn toxicity and/or with Ca and Mg deficiency. Sweet corn was less susceptible to Mn toxicity, but more responsive to exchangeable Ca. The critical level of exchangeable Ca was found to be about 2.0 cmol(+)kg^–1. Applying lime to a band of 0.25-m wide did not reduce yield relative to broadcast. Soil cultivation caused the lime to spread over a wider band, diluting the applied calcium with a larger soil volume, suggesting that less than 6 ton ha^–1 broadcast coarse coralline lime could still be adequate for most Samoan soils.     

加酶浸灰助剂EA应用性能研究

本文对加酶浸灰助剂ＥＡ基本基本使用作了初步探讨。     

鳄鱼皮制革工艺的研究

主要从鳄鱼皮的粒面特点、形态结构及应用等方面出发 ,充分考虑了制革过程中机械磨耗对鳄鱼皮的作用 ,加强了对化工材料的选择 ,同时在灰碱烧鳞、漂色、鞣制、复鞣、染色、加脂、整饰等几个技术关键进行了细致的研究 ,提出了制造高档鳄鱼皮革的制革工艺。     

表面电荷效应对场限环优化设计的影响

本文利用计及表面电荷的柱面结电场分布表达式，并根据场限环优化条件，首次建立了单场限环表面电荷效应优化模型，得到了考虑表面电荷效应后，优化单场限环洁构击穿电压以及优化环间距的归一化计算公式。分析了表面电荷密度对场限环结构耐压和优化环间距的影响，计算结果与文献中的数值模拟结果相符合，推得的公式可应用于场限环结构的实际设计。     

Compensatory fertilization of Scots pine stands polluted by heavy metals

The results from four compensatory fertilization experiments located at different distances (0.5, 2, 4 and 8 km) along a heavy metal deposition gradient extending from the Harjavalta Cu-Ni smelter in SW Finland are presented. The experiments were established in middle-age Scots pine stands growing on dryish sites of sorted glaciofluvial sediments. The soil type in all the experiments is ferric podsol. The treatments in the experiments consisted of liming, a powdered slow-release mineral mixture and stand-specific fertilization which comprised at least methylene urea and ammonium nitrate.Monitoring of deposition and soil solution and studies on soil chemical and microbiological properties, on the nutrient status of trees and needle litterfall, on fine root dynamics and on the growth of the tree stands were carried out during a 5-year period.There was a severe shortage of exchangeable Ca and Mg in the organic layer of the most polluted stands. Although the uppermost mineral soil layer had relatively high exchangeable Ca and Mg concentrations, the trees were not able to utilize these nutrient reserves presumably due to the toxic effects of Cu and Ni on the plant roots and mycorrhizas.The treatments that included limestone markedly decreased the Cu and Ni concentrations in the soil solution and soil organic layer, presumably due to immobilisation through precipitation or absorption. The Ca and Mg concentrations correspondingly increased, which certainly contributed to the partial recovery of fine root and stand growth. The powdered mineral mixture and the combination of methylene urea and ammonium nitrate had no short-term effect on the microbial biomass and activity. All the fertilizer treatments increased volume growth in the most polluted stand. The stand-specific fertilization increased needle mass in heavily polluted stands, but the response of the needle mass to fertilizer treatments was low in the less polluted stands. No clear evidence was found to support the role of nutrient status in tree resistance.     

浸灰助剂的功能及作用原理

阐述了浸灰过程中皮发生的变化及其对革性能的影响,对浸灰助剂的分类、功能和作用原理进行了分析、对浸灰助剂的研究、开发和应用提出了一些建议。     

LA-2复合型浸灰助剂的应用性能

浸灰过程中通过使用浸灰助剂来克服传统灰碱法浸灰的缺点,改善浸灰效果,提高成革质量的方法已被制革者所广泛认同和采用。目前市场上的浸灰助剂牌号众多,质量良莠不齐。要选择、使用好浸灰助剂,必须要了解浸灰助剂的种类、功能和作用原理。本文主要从对浸灰的要求、浸灰助剂应具有的性能和其作用原理的角度对LA-2复合型浸灰助剂的应用性能作了阐述。     

黄牛软鞋面革浸灰工艺研究

对浸灰工艺进行了对比试验研究,以期通过适当的浸灰工艺减少或消除松面、粗皱。通过对浸灰工艺中的液比、浸灰助剂的种类及用量、操作方式等参数进行对比试验,得出了一个较好的浸灰工艺。从根本上解决了黄牛软鞋面革粗皱问题,生产出了粒面平细、柔软、丰满、弹性好且松面率较低的黄牛软鞋面革。     

Clarification of date juice

Summary This study was initiated to utilize a variety of low quality dates (Qish‐Habash) so that high quality syrup could be produced by modifying the clarification process of the date juice. Five different clarification treatments were used: (1) filtration, (2) hot liming and filtration, (3) cold liming and filtration, (4) powder‐activated carbon and filtration, and (5) granular‐activated carbon and filtration. The sugar content, total soluble solids, total ash, pH, colour and purity were analysed to determine the clarification effects. The clarified juices produced by these treatments were evaporated under constant conditions to produce date syrup. Filtration, and activated carbon and filtration were the most successful treatments for the clarification of the date juice. Filtration gave the highest improvement in syrup purity (97.7%), due to the reduction of total ash by 19.5% and colour by 44.6%. Activated carbon removed the juice colour to give the lowest amount (60% in powder form and 57% in granular form), as well as reducing total ash, which led to an improved syrup purity, 92.2% in powder form and 91.4% in granular form. Liming clarification had undesirable effects, by increasing the total ash (15% in hot and 17% in cold lime), and increasing the colouring matter produced by decomposition.     

保毛脱毛制革工艺研究

浸灰是制革准备阶段的一道极为重要的工序,浸灰过程的好坏直接影响着后工序的进行和成革的质量和性能。文章介绍一种保毛脱毛制革工艺,克服传统浸灰工艺存在的缺点和不足,具有脱毛效果好,处理时间短,废水污染物指标显著降低等优点。