改性叶绿素光催化剂的制备及光催化降解双酚A

以天然叶绿素为原料,研制了负载型改性叶绿素仿酶光催化剂,利用X-射线衍射仪、比表面积及孔径测试仪、透射电子显微镜、热重分析仪和振动样品磁强计对催化剂进行了表征;以双酚A为底物,考察了光催化剂吸收可见光催化降解水中酚类有机污染物的特性。结果表明,当双酚A初始浓度为4.38μmol/L、改性叶绿素仿酶光催化剂投加量0.15 g/L、溶液pH为6时,光催化反应360 min,双酚A降解率可达93.65%。在优化降解条件下,催化剂连续使用4次后,催化剂对双酚A的降解率仍达80.54%。同时研究了改性叶绿素仿酶光催化剂降解双酚A的机理。     

高级氧化技术降解双酚A的研究进展

对高级氧化技术降解污水中一种内分泌干扰物双酚A（BPA）的作用机理和研究现状进行了综合评述。针对高级氧化技术中最重要的5种技术,即芬顿氧化及光-芬顿氧化、电化学氧化、光分解及光氧化、超声辐射和光催化氧化,详述了各种氧化技术的作用机理、降解效果以及影响因素等。还对这5种高级氧化技术今后可能的发展方向做了初步展望,鉴于各种高级氧化技术降解BPA的条件不同,通过合理设计多种高级氧化技术复合作用并建立优化模型,开发低能耗、高效率以及广泛适用于内分泌干扰物及持久性有机污染物的处理技术。     

发泡点分析仪的热电偶埋设及测试数据的重现性研究

本文研究了测温热电偶的埋设点在不同条件下的升温重现性,规律性;验证发泡点分析仪BPA使用的可靠性。     

Attachment of foodborne pathogens to banana (Musa sp.) leaves

Fresh produce, and in particular minimally processed leafy green vegetables, have been recognized as a source of transmission for foodborne pathogens of animal origin. In South-East Asian and other cultures the leaves of the banana plant (Musa sp.) are widely used as food wrappings or as serving plates because of their waxy surfaces and represent a largely uninvestigated leafy green product. This study was undertaken to quantify the attachment of two strains of each of the three bacterial foodborne pathogens Staphylococcus aureus, Salmonella enterica and Escherichia coli to the top side and underside of banana leaf surfaces. All bacteria tested attached to banana leaves at levels in the range of 3.5–4.5 cfu/cm². Differences in attachment to leaves between strains were apparent. Most notably both Salmonella strains attached to the top side of leaf surfaces in significantly (p < 0.05) lower numbers than two (one E. coli and one S. aureus) of the other four strains. Furthermore, the two S. aureus strains attached to the undersides of leaves in significantly (p < 0.05) lower numbers than to the top side of leaves. Despite the waxy nature of the banana leaf surfaces the bacteria tested were capable of attaching to them in numbers equivalent to the attachment of bacterial pathogens to other leafy green produce.     

冲突可衡量多源信息融合技术研究

针对传统的基于D-S证据理论的多源信息融合系统中不能衡量冲突程度等问题,提出了冲突可衡量多源信息融合系统.首先提出了一种基于决策表的主客观相结合的获取BPA的方法,其次在得到冲突矩阵和一致矩阵的基础上定义了基于冲突/一致度的冲突衡量标准,然后根据证据的平均冲突度确定其在组合公式中的权重系数,最后在充分利用冲突证据所带来的信息的基础上提出了基于冲突信息的组合规则.仿真实验表明,合成结果不仅符合人类逻辑推理,而且极大地减少了不确定性.     

Weak bisimilarity and regularity of context-free processes is EXPTIME-hard

We show that checking weak bisimulation equivalence of two context-free processes (also called BPA-processes) is EXPTIME-hard, even under the condition that the processes are normed. Furthermore, checking weak regularity (finiteness up to weak bisimilarity) for context-free processes is EXPTIME-hard as well. Adding a finite control of the minimal non-trivial size of 2 to the BPA process already makes weak bisimilarity undecidable.     

基于BPA的电力系统低压减载的研究

低压减载作为电力系统的第三道防线,是维持电力系统安全稳定和经济运行,并保证电能质量的重要措施。依工程实际需求,在电力系统分析软件BPA的基础上,参考国内外现有研究成果,针对分散型低压减载方案,提出基于电压-无功灵敏度减负荷的方法确定低压减载量。采用连续潮流算法,确定薄弱区域的电压-无功灵敏度,最后通过时域仿真分析对所配置的方案进行校验。以河北南网2007年夏季高峰数据为例,验证了该方法具有很好的工程参考价值。     

食品模拟物中双酚A迁移量的间接竞争免疫PCR检测方法

通过抗原-抗体的特异性反应,结合荧光PCR,建立了食品接触材料中双酚A在食品模拟物中迁移量的快速、灵敏的间接竞争免疫PCR检测方法。通过优化包被抗原浓度、探针DNA的量、抗体质量浓度等一系列条件,双酚A的线性质量分数范围在0.01~10 pg/g之间,检测低限为3.0 fg/g,4种食品模拟物中双酚A的添加回收率在82.8%~115.2%,该方法特异性好、灵敏度高,适用于食品接触材料中双酚A及其他小分子化学物的痕量迁移检测,为其迁移行为及迁移模型的建立提供了技术支撑。     

Bisphenol A (BPA) and its source in foods in Japanese markets

The determination of bisphenol A (BPA) and/or bisphenol A diglycidyl ether (BADGE) in foods sold in Japanese markets and in water leached from six epoxy resin cans with similar diameters was carried out using high-performance liquid chromatography (HPLC) with electrochemical detection (LC/ECD), LC-mass spectrometric detection (LC/MS) and LC-tandem mass spectrometric detection (LC/MS/MS). BPA concentrations were 0-842 ng g^-1 for 48 canned foods, 0-14 ng g^-1 for 23 foods in plastic containers, and 0-1 ng g^-1 for 16 foods in paper containers. No BADGE was detected in three canned foods. There was no difference in leaching concentrations of BPA into glycine buffers at pHs 8 and 11, and water. The amounts of BPA leached into water from six epoxy resin cans held at 121°C for 20 min were almost the same as the cans' contents and were much higher than the amounts leached from cans held at or below 80°C for 60 min. The amount leached depended on the type of can, but not on the amount of BADGE leached from the cans. Considerably more BPA than BADGE leached to water from six cans. Two cans whose contents had high concentrations of BPA showed no BADGE leaching even at 121°C, suggesting the different kinds of epoxy resin can linings from others. The results imply that the main source of human exposure to BPA is food from cans with linings that contain high percentages of BPA as an additive or an unforeseen contaminant.     

基于旋转球算法的图像色域的可视化

根据源色域是否基于图像可以将色域映射分成两类,设备到设备和图像到设备。图像到设备的方法考虑到了图像色域是设备色域的一个有限子集,这样就能够避免图像的色域被过度压缩从而可以更好地保护颜色的色貌。在一个基于图像的色域映射算法中图像色域的几何精确度是很重要的因素。本文针对图像色域的构建,提出了一种精确度较高的基于旋转球算法(Ball-Pivoting Algorithm)的图像色域的三维可视化的方法。首先我们用一个通常的分析转换方法将要输出的图像从RGB空间转换到CIEL*a*b*颜色空间,然后我们将CIEL*a*b*颜色空间离散化,再将图像的像素点量化到离散空间的网格点。最后基于旋转球算法实现图像色域的网格点重构。实验结果表明提出的方法能够在不失精确度的同时保持较快的速度,这对于开发基于图像的实时色域映射算法有重要意义。