番茄植株中生物碱类对菜青虫(Pieris rapae L.)活性组分的分离和提纯

为寻找和开发不污染环境、不伤害天敌而对菜青虫有活性的行为物质,本研究对番茄植株中的生物碱类进行提取、分离和部分纯化,得到了极性和非极性生物碱类以及番茄苷(tomatine)纯品,与标样对照薄层试验吻合。将提取物对5龄菜青虫进行试验表明:生物碱类及其中的番茄苷对菜青虫有明显拒食作用;番茄苷对菜青虫有抑制生长发育的作用。     

美国大豆工业海洋网箱水产养殖技术近海海水鱼类养殖网箱工程技术手册(三十五)

3.完整的HDPE边框 在UNH按设计评估完全用HDPE管子和角部连接件建造一个或二个水平边框期间记录了第二组观察资料.在一个边框上取消钢制的角部连接件可以:(1).降低网箱系统的成本;(2)降低网箱的重量;(3)确定了完全用HDPE管子建造一个边框的可行性.     

Effects of High Fluoride and Low Iodine on Thyroid Function in Offspring Rats

Thirty-two Wistar rats were divided randomly into four groups of eight with six females and two males in each group. The rats were exposed to high fluoride drinking water (45 mg F- L-1 from 100 mg NaF L-1), low dietary iodine (0.0855 mg kg-1), or both together in order to assess the effects of these three regimens on the thyroid function of the offspring rats. After the animal model was established, the offspring rats were bred and 10-, 20-, 30-, 60-, and 90-d-old rats were used for the experiment. The treatments for the offspring rats were the same as those of their parents. In comparison with control rats, the relative thyroid glands were changed by three regimens, but the mean values of thyroid weight in the experimental groups saw no marked difference. Serum TT3 levels were increased in all stages in the low iodine (LI) group. In the high fluoride (HiF) group, increase in TT3 levels was observed except in 20-d-old rats. Decrease in TT3 at 20- and 90-d and increase in TT3 at 30- and 60-d were found in HiF+LI group. Serum TT4 levels first saw an increase, and then dropped in the LI and HiF+LI group. However, an increase in TT4 was found in the HiF group. The levels of TSH in serum rocketed at d 20, and then dropped in the next stages in experimental groups. The results suggested that thyroid disorder could be induced by high flroride in drinking water, low iodine diet, or both of them. Exposure time to fluoride or low iodine diet was one of the important factors that fluoride can induce the development of thyroid dyfunction.     

沭阳县颜集虞姬花木合作社建设情况的调研和思考

沐阳县颜集贯勤虞姬花木合作社，实现了农民在市场经济条件下的联合和合作，由过去的松散式产业经营创新发展到目前的利益紧密型产业化经营，提高了农民的组织化程度，改变了农民在市场经济中的弱势地位。给农民带来了实实在在的经济利益，增强了农民抗御市场风险的能力。     

咏梅楹联鉴赏

主要从风景名胜、题赠、挽逝、谐趣等几个方面,对我国历史上的部分咏梅楹联进行了分析、释义和鉴赏。     

元谋县咖啡种植现状和发展浅议

简介云南元谋县咖啡种植历史、现状,存在问题,发展潜力和对策。