PRA参与式方法探讨广西食用菌生产问题

运用参与式农村评估方法,探讨分析广西食用菌生产发展的现状、问题及对策,得出结论,提出建议。     

橡胶树叶片转化酶提取方法的比较

比较液氮研磨样品与蛋白抽提液研磨样品对6种提取橡胶树叶片转化酶方法的效果。结果表明：液氮研磨法对转化酶活性影响很大，特别是中性/碱性转化酶和细胞壁结合的酸性转化酶已基本失活，而可溶性酸性转化酶活性丧失也比较严重。利用蛋白抽提液研磨样品，用Hepes-NaOH法提取的可溶性转化酶的酶活性最高，达472.44 μmol（glucose）/[g（FW）·h]； 虽然磷酸-柠檬酸法获得的粗酶液的蛋白含量较低， 但其酶活性高达441.61 μmol（glucose）/[g（FW）·h]； Tris-HCl法提取的细胞壁结合酸性转化酶的酶活性最高， 达35.83 μmol（glucose）/[g（FW）·h]。从转化酶的比活力看，磷酸-柠檬酸法最佳，所提取的可溶性转化酶比活力约为Hepes-NaOH法的4倍。本研究结果为进一步完善橡胶树叶片转化酶的提取方法提供重要的指导意义。     

藜草花叶病毒的研究概述

藜草花叶病毒(Sowbane mosaic virus,So MV)是菠菜上的重要有害生物,可通过种子、花粉、昆虫介体和机械等方式传播。随着我国种子、种苗进口量的进一步扩大和产业化种植,藜草花叶病毒传入我国的风险非常大。本文综述了藜草花叶病毒的生物学特性、分布、寄主范围、为害症状、传播途径、检测技术等,论述了藜草花叶病毒传入我国的潜在危害性和风险。     

Sulfur content of plant material: A comparison of methods of oxidation prior to determination

Abstract

Procedures for S determination involving digestion of plant material with HNO₃/HClO₄ mixtures gave lower values than those using oxygen flask combustion. Tests on a range of S compounds showed that the HNO₃/HClO₄ procedure underestimated S present in methionine, cysteine and glutathione but S in sulfate and the glucosinolate, sinigrin, was not underestimated.

Low recoveries using HNO₃/HClO₄ digestion procedures can be due both to incomplete oxidation of certain compounds and to gaseous losses during the vigorous boiling stage of digestion.     

A quick method of soil moisture determination

Abstract

The method described here is useful for the quick determination of soil moisture, especially when many determinations are to be made at a time. The only pieces of apparatus required are some wide‐mouthed conical flasks, a few pieces of glass rod and a balance. The principle involves recording the weight of the flask filled with water and soil sample of known weight (A). This flask weight (H), and the predetermined soil particle density (D_p) and weight of the water‐filled flask (G) are then used to calculate moisture percentage (MP) in the soil sample from the formula:

The method was compared with conventional oven‐drying technique for a wide range of soil textures, moisture contents and other contrasting soil properties. The results obtained showed that the accuracy, precision and simplicity of the method are good, particularly for rapid practical uses.     

DPS统计软件在《试验统计方法》课程教学中的应用效果评价

DPS统计软件具有完整的数据输入、编辑、试验设计、统计分析、图形制作等功能,在《试验统计方法》课程教学中,将DPS统计软件作为实验课的教学辅助工具,可激发学生的学习积极性,显著提高教学质量。     

医药院校食品添加剂课程教学探讨

为满足现代社会对食品添加剂安全及使用的要求,培养学生具有合理选择、正确使用食品添加剂以及分析、解决实际问题的能力,对食品添加剂课程定位、教学内容和教学方法进行探索,以期提高食品添加剂课程教学质量.     

中等职业学校《机械基础》课程教学方法探讨

《机械基础》课程是中等职业学校机械类、机电类等专业的一门必修课程,具有知识面广、点多、内容抽象、实践性较强等特点,是较难掌握的一门课程。文章根据教学经验,针对《机械基础》课程教学方法提出了一些观点与看法,以其起到提高教学质量与效果的作用。     

Crown projection area of young Pinus sylvestris: A model and its test

In this study we applied a theoretical model for determining the projection area of a Scots pine (Pinus sylvestris L.) crown in different directions. The model is based on the assumption that the foliage elements (shoots) are randomly distributed within a symmetrical crown envelope. The model was tested using photographically measured data for three young Scots pine crowns. The compatibility between calculated and measured values was satisfactory.     

《基础会计学》教学内容改革探讨

针对基础会计教学中的记账方法、记账凭证及日记账的设置等内容陈旧、落后问题进行了探讨,旨在删减、统一及规范会计的记账方法、记账凭证及日记账的设置,使会计核算内容更适应现代市场经济的发展,尽快与国际接轨.