ORGANIC GEOCHEMISTRY OF ARTIFICIALLY HEATED SPHAGNUM COAL CONSIDERED AS POSSIBLE SOURCE ROCK FOR OIL AND GAS

A preliminary study of simulated thermal maturity has been conducted to evaluate the oil, gas and hydrocarbon generation potential of sphagnum coal in the Jinsuo brown coal basin, Yunnan Province and to understand the characteristics of the element composition and biomarkers in the course of thermal alteration. The experimental result was compared with that of xylitic coal, a kind of lithotype of soft brown coal. It is considered that sphagnum coal possesses the potential of forming economic accumulation of oil and gas. Its highest proportion of oil and hydrocarbon generation is 510 mg/g Corg. and 232.1 mg/g Corg. respectively. At an R_(ran)~° value of 2.51%, the ratio of gas generation from sphagnum coal attains to 620.5 ml/g Corg. In view of sphagnum coal being different from the conventional soft brown coal in various respects such as coal forming raw materials and enviroments as well as physico-chemical properties, it is Suggested as a special kind of source rock for coal-generated oil and gas.     

发芽糙米微量元素锌的生物强化

目的发芽糙米的锌生物强化培育及对人体补锌的适用性探讨。方法选取3个品种(吉梗81号、博优209号、黑糯米)的糙米为材料,用不同质量浓度锌培养液(0~250μg·m L-1)浸种24 h(28℃)并发芽36 h(30℃),在萌发过程中实行锌的生物强化,培育富锌发芽糙米。通过测定不同锌含量条件下发芽糙米的萌发参数(吸水率、发芽率),以及锌、Vc和矿物质(Fe、Mn、Mg)含量,探明培养液锌的适宜含量条件和富锌发米糙米的补锌适用性。结果对吉梗81号、博优209号、黑糯米等3个品种,富锌发芽糙米培育的锌培养液适宜质量浓度均为75~150μg·m L-1,最佳质量浓度为100μg·m L-1。3个品种发芽糙米对锌的富集能力由强到弱顺序为:吉梗81号,博优209号,黑糯米。与对照处理(CK)相比,富锌发芽糙米Vc、GABA含量较高,而矿质元素(Fe、Mn、Mg)渗漏损失略低。富锌发芽糙米每10 g(DW)的锌积累量,对吉梗81号、博优209号及黑糯米等3个品种可提供锌占中国成人RNI百分数分别是:53.8%(男性)和89.7%(女性),45.6%(男性)和76.0%(女性),以及41.1%(男性)和68.5%(女性)。结论发芽糙米可能是进行锌生物强化的优良载体,预计富锌发芽糙米适用于人体补锌。     

Rapid detection of Escherichia coli O157:H7 spiked into food matrices

Food poisoning causes untold discomfort to many people each year. One of the primary culprits in food poisoning is Escherichia coli O157:H7. While most cases cause intestinal discomfort, up to 7% of the incidences lead to a severe complication called hemolytic uremic syndrome which may be fatal. The traditional method for detection of E. coli O157:H7 in cases of food poisoning is to culture the food matrices and/or human stool. Additional performance-based antibody methods are also being used. The NRL array biosensor was developed to detect multiple antigens in multiple samples with little sample pretreatment in under 30 min. An assay for the specific detection of E. coli O157:H7 was developed, optimized and tested with a variety of spiked food matrices in this study. With no sample pre-enrichment, 5 × 10³ cells mL⁻¹ were detected in buffer in less than 30 min. Slight losses of sensitivity (1-5 × 10⁻⁴ cell mL⁻¹⁾ but not specificity occur in the presence of high levels of extraneous bacteria and in various food matrices (ground beef, turkey sausage, carcass wash, and apple juice). No significant difference was observed in the detection of E. coli O157:H7 in typical culture media (Luria Broth and Tryptic Soy Broth).     

甲烷氧化偶联Na2WO4-Mn/SiO2催化剂热效应的研究

采用固定床微型反应装置,研究了甲烷氧化偶联反应过程中Na2WO4-Mn/S iO2催化剂床层的热效应和催化性能的关系,考察了反应炉温、CH4/O2比和反应气体空速对催化剂床层热点分布的影响.研究结果表明,甲烷氧化偶联催化剂床层的热效应强烈依赖于反应条件.反应炉温越高,CH4/O2比越低,反应气体空速越大,催化剂床层的热点温度越高.结合催化性能和热效应关系的研究,为优化甲烷氧化偶联的反应操作提供了实验依据.     

大气颗粒物中棕色碳的化学组成、来源和生成机制

大气颗粒物中棕色碳(BrC)在近紫外波段具有强吸光性,并因其显著的气候效应被广泛关注。BrC组成、来源、演变和光学性质的不确定性是造成气候模型估算气溶胶辐射强迫不确定性的重要因素。本文综述了大气颗粒物中BrC的化学组成、来源和生成机制,聚焦分子水平上BrC组成、二次生成机制和吸光间的关联。大气颗粒物中BrC的主要类别包括有机溶剂(甲醇)提取的碳质组分、水溶性有机碳及类腐殖质; 分子水平上,硝基芳香烃和含氮杂环有机物是BrC的主要发色团。BrC的来源包括生物质等不完全燃烧一次排放和挥发性有机物氧化二次生成; 二次生成途径主要包括人为源芳香烃氧化生成硝基芳香烃等含氮组分、羰基化合物与铵/胺反应生成含氮杂环组分或低聚物。前体物和反应条件影响二次生成BrC的组成和吸光性质; BrC在大气传输过程中还会发生“光漂白”现象。在分子水平上识别和阐明BrC的发色团、二次生成机制及其演变过程是未来该领域的重点研究方向。     

Organic light‐emitting device dark spot growth behavior analysis by diffusion reaction theory

Dark spot growth rate tracing experiments performed on an organic light‐emitting device show that moisture entering into the device is relatively properly fitted by Fick's diffusion equation in the substrate/indium tin oxide (ITO)/hole transport layer (HTL)/silver (Ag) structure. It is believed that the moisture is dissolved into the polymer layer, which results in a decrease in the diffusion coefficient in the device with the substrate/ITO/HTL/electroluminescent (EL) polymer/Ag structure. The diffusion and chemical reaction occurring in the cathode layer further decreases the diffusion coefficient in the device with the substrate/ITO/HTL/EL polymer/calcium/Ag structure. Useful parameters, such as diffusion and solubility constants, describing possible mechanisms happening during dark spot growth on organic light‐emitting diode devices are extracted. © 2001 John Wiley & Sons, Inc. J Polym Sci Part B: Polym Phys 39: 1697–1703, 2001     

广西3种褐煤芳烃生物标志物组合特征

总结了广西三盆地３种第三系褐煤的多环芳烃特征，主要包括芳香倍半萜，二倍半萜和三萜类。其中以陆源奥利烷，乌散烷和羽扇烷前生物衍生而来的单芳于四芳三萜烃类为主，芳香二倍半萜，倍半萜次之 。     

钢桥面板加劲肋焊缝位置热点应力数值分析

采用8节点单元和20节点单元分别建立钢桥面板U肋焊接部位的有限元分析模型,分析不同单元尺寸划分对模型分析精度的影响,对比两种模型计算差异,并分析不同热点应力取值方法的区别.分析结果表明,随着单元尺寸的减小,顶板表面弯曲应力增大,板厚方向弯曲应力增大.相对而言,20节点单元模型计算结果更容易收敛,对于8节点单元模型建议设置8层单元,20节点单元模型建议设置4层单元.在热点应力的取值方法中,表面外推法结果稳定,表面以下1 mm应力法结果受单元尺寸的影响.     

BIC实验的数值模拟研究

为研究低速撞击作用下炸药点火机理,采用非线性动力学LS-DYNA程序和Visco-SCRAM本构模型数值模拟弹道撞击室实验. 计算得到了5.35 m/s初始撞击条件下炸药发生点火反应,与文献中的实验结果比较吻合. 计算结果表明,炸药整体温升并不能导致其点火反应,而裂纹面摩擦生热形成热点能使炸药发生点火反应,计算结果可为低速撞击条件下炸药装药发生非冲击点火反应机理提供新的依据和支撑.      

Fractionation of bacteria by electrophoresis as pre-separation method before MALDI-MS detection

The present study attempted to apply the capillary electrophoresis technique for the fractionation and separation of S. Staphylococcus hominis and Escherichia coli bacteria isolated from urine samples and the detection of migrated fraction with spectrometric method. This involved the selection of suitable conditions for separation as well as the identification of pathogens. The result of the research was the separation of Gram-negative and Gram-positive bacteria, as well as their subsequent identification by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry using two different approaches (culture of fractions on an agar plate and direct analysis of the collected fractions). The preliminary results provide a solid basis for further research on the use of electromigration techniques with LDI detection to identify pathogens such as bacteria and viruses in biological samples.