过氧化物类芬顿体系修复有机污染物的研究进展

环境中有机污染物种类繁多,例如有机卤代物、有机农药和苯系物等。过氧化物常被作为自由基前驱体。基于过氧化物类芬顿系统是实现环境中有机污染物修复的有效技术手段,通过产生羟基等自由基将环境中有机污染物转化为易分解的小分子、CO2和H2O。本文综述了部分学者对过氧化物类芬顿体系降解环境中有机污染物性能、影响因素的研究,阐述了氧化物类芬顿体系所存在的问题,以期为过氧化物类芬顿体系修复环境中有机污染物提供理论技术支撑。     

银杏黄酮对活性氧自由基和过氧化氢清除作用的研究

采用在反应体系中加入大肠杆菌提取物来部分模拟细胞环境,进一步分析银杏叶中黄酮类提取物在细胞内对超氧阴离子自由基、羟自由基清除率和过氧化氢的清除作用.结果表明,黄酮类提取物对两类自由基和过氧化氢有明显的清除作用,但在清除过程中黄酮类与内酯类的相互作用比较复杂.大肠杆菌提取物的生物大分子对自由基和过氧化氢的清除影响较小或没有影响.     

建立脐橙实蝇非疫区研究

建立脐橙实蝇非疫区,围绕脐橙果园桔小实蝇发生规律的研究,综合应用了实蝇的生物学、实蝇的监测、实蝇的综合治理以及果园管理技术,探索在桔小实蝇发生区内建立实蝇非疫区的技术.经过3年的研究,积累了相关的经验,初步探索出研究的方法、程序.在脐橙产区建立实蝇非疫区研究结果表明,在实蝇发生区建立实蝇非疫区是可行的.     

Testing of a six axis computer numberical control abrasive belt grinding machine based on free form surfaces

A highly efficient precision grinding method was proposed for the development of typical free form surfaces such as turbine blades. A six axis simultaneous grinding and polishing machine was created. The machine can polish free form surfaces with abrasive belt grinding technology by computer numberical control(CNC). The key techniques to develop this new grinding machine are presented in detail, including multiple axes rotary spindle grinding head, NC grinding computer aided software, cooling, a scrap removal device, and other features. The experiments of grinding and polishing turbine blades were performed based on different parameters. This research provided sufficient data to confirm reasonable belt grinding and polishing parameters.      

Cadmium Accumulation and Its Toxicity in Brittle Culm 1 （bcl）, a Fragile Rice Mutant

Cadmium （Cd） accumulation and toxicity in rice plants were characterized and identified by using brittle culm 1 （bcl）, a fragile rice mutant and its wild type （Shuangkezao, an indica rice） as materials by hydroponics. The low Cd level didn＇t obviously affect the growth parameters in both rice genotypes, but under high Cd levels （1.0 and 5.0 μmol/L）, the growth of both rice plants were substantially inhibited. Moreover, bcl tended to suffer more seriously from Cd toxicity than Shuangkezao. Cd accumulation in both rice plants increased with the increase of Cd levels. There was a significant difference in Cd accumulation between the two rice genotypes with constantly higher Cd concentration in bcl, which also accumulated more Cd at 0, 0.1, and 1.0 μmol/L Cd levels. The same case was found in the two rice plants grown on Cd-contaminated soil. This suggested that cell wall might play an important role in Cd accumulation in rice plants by the physiological mechanisms. The malondialdehyde （MDA） content, superoxide dismutase （SOD） and peroxidase （POD） activities in rice plants were affected differently under Cd treatments, and which implied that POD might play the main role in detoxifying active oxygen free radical. A significant difference in antioxidative system between the two rice genotypes was found with constantly higher MDA content, SOD and POD activities in bcl. In summary, bcl accumulated more Cd and appeared to be more sensitive to Cd stress compared with its wild type.     

弱光条件下光质对喜树生理生化指标的影响

为给喜树栽培提供理论依据,对弱光环境下红、黄、蓝、绿等光质对喜树幼苗叶绿素含量、超氧化物歧化酶活性、丙二醛、游离脯氨酸和喜树碱含量的影响进行了研究。结果表明:绿光使叶绿素含量增加,而其它单色光使叶绿素含量降低,减少部分主要是叶绿素b,叶绿素(a/b)比值升高;与白光相比黄光使叶片中的超氧化物歧化酶活性升高,而其它3种光条件下的超氧化物歧化酶活性降低;红光使丙二醛含量升高,同时使叶内游离脯氨酸含量持续上升,其它3种光对游离脯氨酸和丙二醛含量影响不大;与白光相比,绿光和红光可使叶片中喜树碱含量增加,而黄光和蓝光不能引起喜树碱含量的增加。弱光条件下不同光质对喜树幼苗生长形成了胁迫,光质对其初生和次生代谢均产生了一定的影响。     

高温胁迫对黄姜叶片脯氨酸、可溶性糖和丙二醛含量的影响

通过对高温胁迫下不同居群黄姜叶片中脯氨酸(Pro)、可溶性糖和丙二醛(MDA)的含量变化进行研究,结果发现,随着胁迫进行,不同居群黄姜叶片中脯氨酸和可溶性糖含量逐步升高;高温胁迫导致不同居群黄姜叶片中丙二醛含量先升后降,这一变化规律不同于其他植物。进一步分析表明,原产地为湖北十堰、湖南泸溪和陕西安康及石泉4个居群的黄姜在高温胁迫下累积脯氨酸和可溶性糖的能力较强。     

药用鼠尾草二萜醌类及有关中药单体对羟自由基的清除效能

采用电子自旋共振和自旋捕集技术,观察药用鼠尾草丹参二萜醌类化合物及其它中草药中有关单体化合物对Ｆｅｎｔｅｎ 反应产生的羟自由基的清除效能。结果表明,试验浓度的二萜醌类化合物对羟自由基有不同程度的清除作用,其中对醌类的抑制作用强于邻醌类。含多羟基醌类化合物具有较强的清除效能,分子中的羟基对消除自由基有促进作用。在一定浓度范围内,隐丹参酮对羟自由基有较好的清除作用。     

冷温血停搏液联合灌注对犬心肌氧自由基代谢的影响

为探讨含血停搏液不同灌注对心肌保护效应,将２８只低温体外循环犬随机分为４组：冷晶组（对照组,ｎ＝７）,低温体外循环冷晶停搏液间断灌注;冷血组（ｎ＝７）,低温体外循环１０℃冷血停搏液间断灌注;温血组（ｎ＝７）,低温体外循环冷晶停搏液诱导,开放前温血灌注;冷温血组（ｎ＝７）,低温体外循环２０℃冷血多次间断灌注与开放前温血联合灌注。从氧自由基损伤机制入手,于心肌缺血再灌注期不同时点抽取冠状静脉血样,测定血清丙二醛（ＭＤＡ）含量及血清超氧化物岐化酶（ＳＯＤ）、谷胱甘肽过氧化物酶（ＧＳＨ－Ｐｘ）活性。结果显示,冷温血联合灌注组在主动脉开放１５ｍｉｎ至６０ｍｉｎ各时点,血清ＭＤＡ含量增加,ＳＯＤ、ＧＳＨ－Ｐｘ活性下降,与冷晶组、冷血组和温血组对应时点比较,增加和下降幅度均较小,差异显著（Ｐ＜０．０５或Ｐ＜０．０１）,提示２０℃冷血与３７℃温血停搏液联合灌注能获得最佳的心肌保护效果。     

肉仔鸡血浆游离氨基酸浓度变化规律的研究

给４ 组共４０ 只肉仔鸡分别强饲无氮饲粮（ＮＦＤ）、ＮＦＤ＋ ３２ ｇ·ｋｇ－ １酶解酪蛋白（ＥＨＣ）,及以豆粕为惟一氮源的粗蛋白质量浓度为５０ 和２００ ｇ·ｋｇ－ １的饲粮,于强饲后５ ｍ ｉｎ,４,２４,３６ 及４８ ｈ,采集静脉血液,观测去蛋白血浆中诸氨基酸（ＰＦＡＡ）的变化规律。结果表明,ＰＦＡＡ 浓度与采食饲粮氨基酸含量及食后时间呈复杂的函数关系。ＰＦＡＡ 浓度仅可大致估计饲料氨基酸的有效性。