青菜对14CO2的吸收和积累动态

为了探明¹⁴CO₂在环境中的行为,采用同位素示踪技术研究了青菜对¹⁴CO₂的吸收和积累动态.结果显示,通过叶片光合作用从空气中吸收的¹⁴CO₂会向青菜其他部位组织输送并形成积累趋势,各部位组织中^１４Ｃ比活度随时间呈线性增长,增长速率介于95.3～270.2 Bq/(g·d)范围内, 大小次序为:菜心＞叶＞叶柄＞茎盘＞根.青菜对¹⁴CO₂(^１４Ｃ)具有强烈的富集作用,各部位的富集系数随时间呈快速增加,积累效应十分明显,其中菜心中的富集系数最大(48 d时高达156.4),叶片次之(48 d时为135.6). 青菜各部位^１４Ｃ比活度均随¹⁴CO₂引入次数的增加而递增,回归分析表明:各部位组织中^１４Ｃ比活度C的变化与引入次数N间呈线性正相关.青菜对空气中¹⁴CO₂的高富集特性可用来作为监测大气¹⁴CO₂污染的指示作物.     

Alkaline phosphatase activity in the phosphorus-limited southern Chinese coastal waters

Three fractions of alkaline phosphatase activity(APA), including phytoplankton APA(phyto-APA), bacterial APA(bact-APA), and free-APA, were examined in the sea surface microlayer(SML) and the subsurface water(SSW) from Daya Bay, Guishan Island, and Guanghai Bay of southern China. Relationships between APA and environmental parameters were analyzed. The growth of phytoplankton was significantly limited by dissolved inorganic phosphorus(DIP) in the three sea areas, especially in Daya Bay. TotalAPA ranged between 1.41 and 35.26 nmol/L/hr, and the highest value was found in Daya Bay. The increased APA in Daya Bay was the result of the increase of phytoplankton biomass and the response of phytoplankton to P limitation. Phyto-APA was the main contributor in Daya Bay, while phyto-and free-APA co-dominated in Guishan Island and Guanghai Bay. Bact-, phyto-, and total-APA showed a significant inverse power function relationship with DIP, and 0.2 μmol/L was the threshold for DIP on particulates and totalAPA. Pearson correlation analysis suggested that DIP limitation together with high N levels enhanced APA. High water temperature and freshwater input accelerated APA as well.Principal component analysis clearly separated samples from the three sea areas, as well as from the SML and the SSW, which indicated the differences in environmental parameters and APA levels. Our results highlight the influence of phosphorus limitation and environmental parameters on APA.     

5种酚类物质对中国白羽鹌鹑和中华蜜蜂的急性毒性

酚类物质作为一类主要的污染物,已引起国内外高度重视,但目前其对陆生生物的毒性研究较少。本试验探究了4-叔丁基苯酚、间甲酚、2-氯苯酚、2-甲酚、2,4-二氯苯酚这5种酚类物质对中国本土物种中国白羽鹌鹑和中华蜜蜂的急性毒性。在中国白羽鹌鹑的急性经口试验中,2-氯苯酚、2-甲酚的7 d的半致死浓度(7 d-LC50)分别为331 mg·kg~(-1)和413 mg·kg~(-1),其他3种酚类物质的7 d-LC50均大于限度值1 000 mg·kg~(-1);在中国白羽鹌鹑的急性饲喂试验中,5种酚类物质的8 d-LC50均大于限度值2 000 mg·kg~(-1);在中华蜜蜂的急性经口试验中,2-氯苯酚、2-甲酚和2,4-二氯苯酚的48 h-LC50分别为306 mg·L~(-1)、358 mg·L~(-1)和364 mg·L~(-1);在中华蜜蜂的急性接触试验中,2,4-二氯苯酚的48 h的半致死量(48 h-LD50)为2.6μg·蜂~(-1),其他4种酚类物质的48h-LD50均大于限度值100μg·蜂~(-1)。研究结果表明不同的酚类物质由于其结构不同亦表现出不同的毒性,甲酚的邻位取代比间位取代对中国白羽鹌鹑和中华蜜蜂的毒性更高,不同物种表现出了相似的规律性。5种酚类物质对我国本土物种中国白羽鹌鹑和中华蜜蜂毒性比对其他水生生物更敏感,存在良好的剂量效应关系。     

氰戊菊酯对斑马鱼和稀有鮈鲫不同生命阶段的毒性效应

为探明氰戊菊酯对鱼类不同生命阶段的毒性效应,以斑马鱼和稀有鮈鲫为测试生物,评价了氰戊菊酯对斑马鱼和稀有鮈鲫不同生命阶段的急性毒性差异。研究发现,氰戊菊酯对斑马鱼和稀有鮈鲫胚胎的96 h-LC50值分别为0.901(0.664~1.22)和0.636(0.233~1.74)mg·L~(-1)。氰戊菊酯对稀有鮈鲫胚胎孵化有明显的促进作用,染毒48 h后,0.188和0.375 mg·L~(-1)氰戊菊酯对稀有鮈鲫胚胎的孵化率分别为88.9%和100%。氰戊菊酯对斑马鱼仔鱼、幼鱼和成鱼的96 h-LC50值分别为0.00340、0.0183、0.00487 mg·L~(-1),氰戊菊酯对稀有鮈鲫仔鱼、幼鱼和成鱼的96 h-LC50值分别为0.0520、0.00277、0.00345 mg·L~(-1)。因此,氰戊菊酯对斑马鱼不同生命阶段的毒性从高到低顺序依次为:仔鱼成鱼幼鱼胚胎,氰戊菊酯对稀有鮈鲫胚胎、仔鱼、幼鱼和成鱼的毒性为幼鱼成鱼仔鱼胚胎。试验结果表明,斑马鱼仔鱼对氰戊菊酯的敏感性高于稀有鮈鲫相应的生命阶段,相对于斑马鱼,稀有鮈鲫胚胎、幼鱼以及成鱼对氰戊菊酯的毒性作用更为敏感,说明氰戊菊酯对斑马鱼和稀有鮈鲫不同生命阶段的毒性效应差异较大。     

中药废水污染特点和处理研究进展

分析了我国中药废水污染的特点,中药制药业水污染防治技术研究中的各种物化、化学、生物处理技术的研究现状,并对各种制药废水污染防治技术的特点进行了分析,最后指出了中药废水处理工艺的选择问题.     

智能应力或结构损伤自敏涂层研究现状及展望

详细介绍了机械零部件表面应力和结构损伤检测的研究现状,重点介绍了荧光涂层应力检测的原理、优势以及发展现状.分析了基于稀土荧光离子的应力检测涂层的需求,并就其应用原理和发展现状进行了表述.介绍了不同材料体系下应力及结构损伤检测范围,以及应力自敏涂层目前的应用现状和未来发展趋势.     

Safety performance measurement in collectivized oil companies in China: Contribution of leading indicators to lagging indicators

With the collectivization of the Chinese oil industry, oil companies have been expanding in size. However, the intensified differences in the safety performance of subsidiaries have severely hindered the collaborative management of the headquarters. Understanding the safety status of each member is urgent for parent companies and their subsidiaries to identify gaps and make improvements. A unified set of safety performance indicators and a practical measurement tool are essential for the Chinese oil industry. Hence, this study identified a set of safety performance indicators encompassing both leading and lagging indicators using data envelopment analysis (DEA) and entropy weight method (EWM) to reveal the critical factors affecting the safety performance of the oil industry. A total of 300 front-line workers from eight subsidiaries of an oil company participated in the survey. The identified indicators were preliminarily weighted using EWM. Then, DEA was employed to measure the safety performance of the eight subsidiaries, demonstrating that management commitment was the most crucial factor in distinguishing safety performance; safety culture was more differentiated than risk management. Safety performance was not entirely positively correlated with safety investments, but the reasonable allocation of safety resources played a vital role. In addition, the weaknesses in each subsidiary's safety management were identified, and the quantitative effects of each leading indicator on safety performance were obtained.