乙烯系单体自由基聚合的阻聚效应(ⅩⅪ)——羟胺类化合物对苯乙烯—甲基丙烯酸甲酯共聚合的影响

研究了二乙基羟胺（ＤＥＨＡ）、二异丙基羟胺（ＤＩＰＨＡ）和吗啉羟胺（ＭＰＨＡ）对偶氮二异丁腈（ＡＩＢＮ）引发的苯乙烯（Ｍ１）－甲基丙烯酸甲酯（Ｍ２）在６０℃共聚合的行为．结果表明,３种羟胺对Ｓｔ－ＭＭＡ共聚合表现出不同的阻聚功效,它们的阻聚活性次序为ＤＥＨＡ＞ＤＩＰＨＡ＞ＭＰＨＡ．同时观察到Ｓｔ－ＭＭＡ共聚合竞聚率发生变化,随着所用羟胺的浓度加大,Ｓｔ－ＭＭＡ交替共聚合倾向增大．此外还讨论了聚合温度对诱导期、共聚合速率和共聚物组成的影响．     

The inhibition of corrosion of aluminum in acid environment byin situ electrocoagulation of polybutadienoic acid

The dissolution rate of naked Al sheet in the acidic solutions containing polybutadienoic acid (PBA) with pH value of 0.3∼3.0 at 20∼60°C has been determined by electrometry and gravimetry methods. The form of electroactive Al(III) ions occurred on the anode and the behavior of electrocoagulation of PBA have been approached. The results indicate that the superior condition of electrocoagulation of water-soluble nonsaturable low polymer PBA is the adoption of the electroactive Al(III) ions occurred in electrolyte containing 1.0 g·L⁻¹ PBA+0.2 mol·L⁻¹C₆H₈O₇ citric acid with pH value of 3.0 at 30°C. The mechanism of corrosion-inhibited or electrocoagulation resulted from the electroactive Al(III) ions coordinate-COOH group of PBA and free ions of citric groups into the aluminum soaps with bicyclic structure are briefly discussed in this paper. Supported by the National Natural Science Foundation of China Tao Yingchu: born in 1943, Professor     

对羟基苯甲酸对酪氨酸酶的抑制作用

报道对羟基苯甲酸对酪氨酸酶的竞争性抑制作用．以０．６０７ｍｍｏｌ／ＬＬ－酪氨酸为底物,酶浓度为０．６６ｍｇ／ｍＬ时,最大抑制率达４２．８６％,抑制常数为２．８３×１０－４ｍｏｌ／Ｌ,并探讨抑制机制     

Ancient DNA: Methodological challenges

The study of ancient DNA offers the possibility of following genetic change over time. However, the field is plagued by a problem which is unique in molecular biology-the difficulty of verifying results by reproduction. Some of the reasons for this are technical and derive from the low copy number and damaged state of ancient DNA molecules. Other reasons are the unique nature of many of the objects from which DNA is extracted. We describe methodological approaches with which these problems can be alleviated in order to ensure that results are scientific in the sense that they can be reproduced by others.     

季鏻盐同阴离子对铝缓蚀的协同作用

在１ｍｏｌ·Ｌ－１Ａｌ（ＣｌＯ４）３溶液中，用微分极化电阻测量技术和交流阻抗法研究阴离子ＳＨ－和ＳＣＮ－对溴化丁基三甲基　（ＢＴＭＰＢ）对铝的缓蚀作用及吸附行为的影响．结果表明，ＳＨ－和ＳＣＮ－能显著提高ＢＴＭＰＢ对铝的缓蚀效率，两者和ＢＴＭＰＢ对铝的缓蚀具有明显的协同作用．在高氯酸铝溶液中ＢＴＭＰＢ在铝／溶液界面上的吸附服从Ｌａｎｇｍｕｉｒ吸附等温式，且为物理吸附，但是当在１ｍｏｌ·Ｌ－１高氯酸铝溶液中加入１×１０－４ｍｏｌ·Ｌ－１的ＳＨ－或ＳＣＮ－时，ＢＴＭＰＢ在铝／溶液界面上的吸附为化学吸附，且服从修正的Ｂｏｃｋｒｉｓ－Ｓｗｉｎｋｅｌｓ吸附等温式。     

植物病原细菌的细菌素与细菌性病害的防冶

本文介绍了细菌素的一般性状,化学性质、遗传学基础及其在植物细菌性病害防治中的应用,探讨了细菌素在防病实践中存在的问题及解决途径。     

农业经济转型中的金融抑制及金融深化

经济稳定增长依赖于金融供给和需求.如果在金融需求一定的条件下,金融供给小于金融需求,则形成供给型金融抑制;如果现实的金融需求小于潜在的金融需求,则形成需求型金融抑制.我国的农业经济转型中的金融抑制既包括供给型金融抑制,也包括需求型金融抑制.因此,农业经济转型中的金融深化要分别从供给金融深化和需求金融深化入手.     

微量血凝抑制试验监测技术在鸡新城疫防治中的应用

本文介绍了用微量血凝抑制试验方法监测鸡血清中鸡新城疫（ND）抗体效价在防治该病中三个方面的应用，为临床合理免疫、科学预防提供了依据。     

YX拟青霉菌发酵浓缩物对马铃薯晚疫病菌的抑制作用

 测定YX拟青霉菌发酵浓缩物(YFC)对马铃薯晚疫病菌的抑制作用,发现YFC对晚疫病菌菌丝生长具有明显的抑制作用,2 g/L的YFC对菌丝生长的相对抑制率达63.00%;经YFC处理后的晚疫病菌丝扭曲、分枝增多、菌丝膨大、变形甚至断裂;盆栽实验中YFC质量浓度为4 g/L时对马铃薯晚疫病的预防和治疗效果分别为83.35%和35.63%.     

36种家庭日用化学品抑菌效果的研究

采用点样法测定不同品牌的牙膏、洗衣粉、洗洁精、洗发露以及化妆品等36种家庭日用化学品的抑菌效果．结果表明：洗衣粉、洗洁精以及洗发露3种家庭常用洗涤剂对大肠杆菌(E．coli)、枯草杆菌(B．subtilis)和金黄色葡萄球菌(s．aureus)的抑菌作用较好；洁诺牙膏，雕牌洗洁精，潘婷、风影和海飞丝洗发露对大肠杆菌抑制作用明显，抑菌圈直径大于20mm；雕牌、海利尔、立白和白猫洗洁精，飘影、潘婷、风影和强生婴儿洗发露对枯草杆菌抑制作用明显，抑菌圈直径大于20mm；牙膏、洗洁精、洗衣粉和化妆品对金黄色葡萄球菌的抑制作用有所不同，抑菌圈直径介于5～20mm之间．