美洲商陆和籽粒苋对接种伯克氏菌的生理生化响应及其对富集铯的影响

利用盆栽试验研究一株具有重金属耐性的伯克霍尔德氏菌(Burkholderia sp.D54)对美洲商陆和籽粒苋生长及对铯富集的影响.结果表明,接种菌株D54,美洲商陆和籽粒苋总干物重分别比对照处理增加19.8%～33.4%和22.9%～76.6%,美洲商陆和籽粒苋地上部铯含量分别增加4.9%～22.4%和8.1%～19.4%,根中铯含量分别增加6.8%～15.7%和1.1%～10.8%.同时,接种微生物还增加了植物对钾的吸收,提高供试植物的光合反应速率、气孔导度、蒸腾速率和水分利用率,增加铯胁迫条件下植物的抗氧化酶CAT、POD、SOD的活性,降低了MDA的含量.     

虹鳟鱼鳃及肝脏多种CYP1基因表达模式作为生物标志物监测海河水污染状况

以虹鳟鱼为受试生物,以鳃与肝脏多种CYP1基因为生物标志物,在天津境内开展了野外监测实验,分析多种CYP1转录物的表达量变化及它们在不同监测位点的表达模式.实验通过鱼类吊网在特定水域进行野外监测.结果表明,葛沽与海河入海口的6种CYP1基因表达模式很相近,但表达量不同,表明两地的污染成分相近似但水中污染物负荷不同.除了在马厂减河外,CYP1C1/C3在葛沽与入海口受到明显诱导作用,表明马厂减河中存在的污染物种类不同于其它监测位点.因此,利用虹鳟鱼鳃与肝脏中多种CYP1基因表达模式作为生物标志物监测污染物有着很好的前景,不仅可以作为研究环境污染物对水环境和鱼类健康影响的重要手段,还可以为进一步解释化学混合物成分与多种生物反应之间关系提供理论基础.     

Design training and aesthetic evaluation: An intergroup comparison

A number of studies have observed differences in the evaluation of visual, aesthetic stimuli between those with and without professional training in art and design. If exposure to design training underlies such differences it follows that evidence of training effects should be observable when comparing subjects at different stages of design training, and not observable when comparing subjects at different stages of non-design training. In addition, this evidence should be consistent with directional predictions. The study reported in this paper investigated this question using a sample of 192 trained and untrained subjects in an evaluative task. Subjects were from two departments (Design and Computer Studies) of the same educational establishment and comprised balanced groups of lecturers, 1st, 2nd and 3rd year undergraduate students. The results obtained demonstrated evaluative differences and patterns of association both within and between the subject groups consistent with a training hypothesis.     

Acute toxicity of two insecticides to tubificid worms, Tubifex tubifex and Limnodrilus hoffmeisteri

Acute toxicity and presumable harmless concentration of two commercial insecticides, Furadan 3G and Malataf 50E were reported for tubificid worms, Tubifex tubifex and Limnodrilus hoffmeisteri. L. hoffmeisteri were found more susceptible to both the insecticides; the Furadan was found to be more toxic than Malataf to tubificid worms. Analysis of variants showed a significant difference between safe concentrations of the same insecticide to different species.     

HUD状态下飞行员视觉注意资源分配机制研究

为了解决平视显示器（Head Up Display,HUD）飞行中的注意资源分配问题，基于飞行模拟器，设计双作业飞行任务开展相关研究。基于事件相关电位（Event Related Potential，ERP）技术，选取行为绩效和P300成分为评价指标，采用oddball模式，在双作业飞行任务条件下开展实验研究。结果表明:随主任务难度的增加，主、辅任务的作业绩效均显著下降，被试者对HUD上异常信息的正确操作率降低，且反应时间延长；随主任务难度的增加，由辅任务所诱发的P300的波幅显著降低。在实验结果的基础上，最终提出了HUD状态下飞行员视觉注意资源分配机制。     

海洋苯酚降解菌Candida sp.P5的分离鉴定及其降解特性

从海洋沉积物中分离、筛选到一株能以苯酚作为唯一碳源和能源的酵母菌P5.根据菌落特征、菌体形态、生理生化特性和18S rDNA序列分析,确定菌株P5为假丝酵母菌属(Candida sp.).该菌株最适宜生长和降解苯酚的条件为:温度25℃,pH6.0～7.0,摇床转速100r/min,需氧;菌株P5能在较高浓度的苯酚条件下生长,在72h内可以降解95%以上的苯酚.对苯酚代谢途径和相关酶的研究发现,菌株P5主要在邻苯二酚1,2-双加氧酶作用下通过邻位途径进行苯酚代谢.图7表2参24     

衍生化气相色谱法测定黄磷诱发氧化水中苯酚降解产物

利用衍生化气相色谱法对黄磷诱发氧化苯酚降解产物进行了研究，在磷酸存在下，以甲醇作酯类衍行生试剂，分别和ＳＥ－５２和ＨＰ－１７石英毛细管双柱结合ＧＣ－ＭＳ进行分离定性定量，黄磷诱发氧化苯酚降解产物以羧酸为主，在反应温度５０℃时，表现为一级反应特征，速率常数（Ｋ）：０．０７７ｍｉｎ＾－１，半衰期（ｔ１／２）：９．０ｍｉｎ。     

不同利用方式下黄壤旱坡地磷素状况及环境影响分析

通过对贵州黄壤进行采样以及采用无界径流小区法收集地表径流,探索不同利用方式下黄壤旱坡地磷素水平及其地表径流磷浓度的差异。结果表明,不同利用方式下黄壤旱坡地中全磷和有效磷(Olsen-P)含量的大小顺序为连作烟地>烤烟-玉米轮作地>连作玉米地>林地;CaCl_2浸提磷(土壤易解吸磷)和Na0H浸提磷(藻类可利用的土壤总磷)与土壤全磷和有效磷有显著的相关性;土壤富磷化的同时,其磷素的流失风险明显地提高。连作烟地地表径流总磷(TP)和磷酸根态磷(Ortho-P)浓度明显大于连作玉米地.而林地地表径流TP浓度明显小于旱地;黄壤旱坡地地表径流中TP和Ortho-P与土壤有效磷之间存在极显著的相关性(r为0.957、0.875),因而连作烟地磷素的环境影响潜能明显高于其它旱地以及林地。     

An improved technique for the determination of organic phosphorus in sediments and soils by 31P nuclear magnetic resonance spectroscopy

Knowledge of organic phosphorus (P) species quantity and distribution in sediments and soils is needed to determine the potential for aquatic and terrestrial organism growth. This can be achieved with ³¹P nuclear magnetic resonance spectroscopy (NMR), but resolving peaks within spectra can be problematic because of broadening via paramagnetics, which can cause peaks to overlap. We compared ³¹P NMR spectra of NaOH-EDTA extracts of three sediments and three soils to those that had first been pre-treated with Ca-EDTA-dithionite to remove Fe and Mn, paramagnetics that cause broadening of peaks, but leave organic P alone. Broadening of peaks in Ca-EDTA-dithionite pre-treated samples decreased by 46% and revealed peaks that were hidden compared to untreated samples. The spectrum of one pre-treated soil was similar if not better than the same soil that had received pre-treatment with Chelex resin (also to remove paramagnetics). Therefore, pre-treatment with Ca-EDTA-dithionite is recommended as a simple and cost-effective method for improving organic P idenTIFication and determination in subsequent NaOH-EDTA extracts of sediments and soils rich in Fe and Mn.