危害电工电子产品的生物霉菌

本文分析了霉菌对电工电子产品的影响,并指出预防方法。     

Sustainable Exploitation of Borassus aethiopum, Elaeis guineensis and Raphia hookeri for the Extraction of Palm Wine in Côte d'Ivoire

In the rural areas of developing countries palms are major sources of many products. One of these is palm wine, which has an important role for nutrition, income and social life. In the Côte d'Ivoire (West Africa), palm wine is extracted from three different species: Borassus aethiopum Mart., Raphia hookeri Mann & Wendland and Elaeis guineensis Jacq. As the extraction methods are destructive, palm stands are locally threatened by extinction. This could have serious consequences not only for the nutritional situation of the population but also for their income. Field visits were conducted in order to assess the degree of sustainability of palm wine extraction in eight villages of Côte d'Ivoire's three major agro-ecozones. Based on the annual palm wine need for consumption and commercialisation and on the availability of palms, a sustainability index was calculated for each palm species in each village. The occurrence of palm trees depends on the vegetation type. B. aethiopum is a typical savanna tree (> 20 palms per hectare) and is almost absent in other vegetation types. In 75% of the villages the exploitation of B. aethiopum is not sustainable. The preferred vegetation type for R. hookeri is the forest along the rivers (> 33 palms per hectare) compared to the other vegetation types of the forest zone (< 5 palms per hectare). Due to the high preference for the palm wine of this species its exploitation is not sustainable in any of the selected villages. The distribution of E. guineensis depends mostly on human activities, the main vegetation types being plantations (34 palms per hectare), fallow land and cultivated fields (15 palms per hectare) and the forest along the rivers (31 palms per hectare). The exploitation of this species is in general sustainable throughout all ecozones with some rare exceptions.     

利用数学模拟方法分析硝化MBR系统中SMP转换过程

为深入了解膜生物反应器（MBR）中微生物代谢产物（SMP）的生成降解以及利用情况,研究了以NH4Cl为惟一能源物质的硝化MBR反应器中SMP浓度以及分子量（MW）变化情况,并运用活性污泥模型3（ASM3）准确地计算出微生物利用底物相关的溶解性产物（UAP）和微生物死亡相关的溶解性产物（BAP）的量分别是多少,最终证明硝化系统中产生的SMP可作为能源物质被异养菌进一步利用,而且相较于BAP而言UAP更易于被生物降解,得出结论BAP是SMP中的主要污染成分。     

Photodegradation of malachite green under natural sunlight irradiation: kinetic and toxicity of the transformation products

This article describes the photolytic degradation of malachite green (MG), a cationic triphenylmethane dye used worldwide as a fungicide and antiseptic in the aquaculture industry. Photolysis experiments were performed by direct exposure of a solution of MG in water to natural sunlight. The main transformation products (TPs) generated during the process were identified by liquid chromatography time-of-flight mass spectrometry (LC–TOF-MS) and gas chromatography mass spectrometry (GC–MS). The 28 TPs identified with this strategy indicate that MG undergoes three main reactions, N-demethylation, hydroxylation and cleavage of the conjugated structure forming benzophenone derivatives. These processes involve hydroxyl radical attack on the phenyl ring, the N,N-dimethylamine group and the central carbon atom. The Vibrio fischeri acute toxicity test showed that the solution remains toxic after MG has completely disappeared. This toxicity could be assigned, at least in part, to the formation of 4-(dimethylamine)benzophenone, which has an EC_50,30 min of 0.061 mg l⁻¹, and is considered “very toxic to aquatic organisms” by current EU legislation.     

Effects of cultivation conditions on the diversity of microbes involved in the conversion of rice straw to fodder

To confirm the optimum cultivation conditions for analyzing lactic acid bacterial communities and to provide the cultivation foundation for lactic acid bacterial communities that were used to convert straw into fodder, fermented rice straw was inoculated into 13 different broths. After 48 h of cultivation, pH values, volatile products, and microbial diversity were analyzed. Except for LAB broth, the pH values of the other broths could decrease to approximately 4.5. GC/MS analysis showed that lactic acid in Tomato MRS broth, MRS broth, LAB broth, and Tomato juice broth was higher than that in the other broths. DNA concentration analysis showed that the counts of microbes in Tomato MRS broth were 2.5 times of those in other broths and that tomato juice favored the reproduction of the microbes. Denaturing gradient gel electrophoresis （DGGE） analysis showed that the number of lactic acid bacterial species in HYA broth, Tomato juice broth, and Tomato MRS broth were higher than those in the other broths.     

Formation of multiple trimethylsilyl derivatives in the derivatization of 17α-ethinylestradiol with BSTFA or MSTFA followed by gas chromatography-mass spectrometry determination

N,O-bis(trimethylsily)trifluoroacetamide (BSTFA) and N-methyl-N(trimethylsily) trifluoroacetamide (MSTFA) are common derivatization reagents used in the GC-MS analysis of estrogen steroids such as estrone (E1) and 17(-ethinylestradiol (EE2). In this study, three trimethylsilyl (TMS) steroid derivatives, mono-and di-trimethylsilyl EE2 and mono-trimethylsilyl E1, were observed during the derivatization of EE2 with BSTFA or MSTFA and/or GC separation. Factors influencing the production of multiple TMS derivatives and their relative abundance were examined. It was found that both methanol and bisphenol A competed with estrogenic esteroids when reacting with silylation reagents, and thus affected the formation of TMS derivatives and their relative abundance in the derivatization products. Methanol was found to be more reactive than bisphenol A with the BSTFA reagent. None of the three solvents tested in this study could prevent the generation of multiple TMS derivatives during the derivatization of EE2 with BSTFA, followed by GC analysis. A similar result was observed using MSTFA as the derivative reagent followed by GC analysis. Thus, the suitability of BSTFA or MSTFA as the derivatization reagent for the determination of E1 and EE2 by GC-MS, under the conditions reported here, is questionable. This problem can be solved by adding trimethylsilylimidaz (TMSI) in the BSTFA reagent as recommended, and the performance of the method has been proved in this study.     

养殖池塘生态系统中磷的收支及解磷微生物的研究进展

综述了池塘养殖系统磷的收支情况.研究发现,在池塘养殖系统中,磷输出最主要的形式为底泥沉积,养殖池塘中存在着磷的总体利用效率不高,水体中活性磷含量低的问题.而解磷微生物的应用在一定程度上可有效解决上述问题,它们能将植物难以吸收利用的磷转化为可吸收利用的形态.通过阐述解磷微生物的种类、解磷效果及解磷机制,结合养殖池塘的情况,分析了将解磷微生物应用于水产养殖中的可行性,并对今后的研究方向作出了展望.结合我国水产养殖的实际情况,筛选适应池塘养殖环境的高效解磷微生物,并将其应用于池塘养殖中,使池塘沉积物中难溶性磷转化具备相当的可行性.     

基于虹膜识别的肉类食品可追溯系统研究

为了加强食品安全管理,提高肉类食品溯源准确性的目的,首先提出肉类食品溯源体系的3个基本要素,认为:动物个体识别是肉食品质量控制的重要环节;采用虹膜识别作为大型动物个体识别的关键技术;解决了其他动物识别系统中的欺骗以及设备功能异常现象等问题。以奶牛为例,讨论人眼虹膜识别技术应用于大型动物识别在图像采集、虹膜定位、特征提取3方面存在的技术难点;给出了实现动物虹膜识别的技术路线;最后构建了基于虹膜识别的肉食品可追溯系统。通过详细功能划分和流程设计,为虹膜技术在肉食品可追溯系统中的应用实施提供了参考。     

埋地成品油管道绝缘接头漏电失效特征分析

目的 分析兰成渝成品油管道某管段绝缘接头漏电失效的原因以及对阴极保护有效性产生的影响.方法 通过电位测量、电阻测试、漏电率测试等方法对管道阴极保护系统中恒电位仪、绝缘接头绝缘性能等进行检测.对该管段进行阴极保护输出、绝缘接头两端电位等参数的返场调研检测,对绝缘接头失效部位管内腐蚀产物成分及形貌进行表征.结果 恒电位仪在...     

固定化菌剂载体材料腐解产物对污染土壤中芘解吸的影响

以老化120 d初始浓度为20 mg·kg-1的人为芘污染土壤为研究对象,利用批量吸附-解吸实验,分析了固定化菌剂载体材料玉米芯腐解产物(水溶性和非水溶性)对污染土壤芘解吸的影响.结果表明:1腐解产物的加入不仅提高了土壤中芘的快速解吸分数,而且大大增加了土壤中芘的解吸率.腐解1 d和120 d非水溶性腐解产物的加入使土壤芘解吸率由20.0%分别增大到81.8%和84.5%;腐解1 d和120 d水溶性腐解产物的加入使土壤芘解吸率由约40.0%分别增大到89.6%和88.5%.2与未腐解玉米芯吸附量相比,腐解1 d和120 d的玉米芯对芘的吸附量分别增大了9.4和16.6倍.而腐解1 d和120 d后获得的水溶性产物能够使XAD-2树脂吸附量增加1.5和3.1倍.以上结果表明固定化材料可以通过吸附或活化作用促进土壤残留污染物的释放.