同位素稀释-液相色谱-串联质谱法同时测定养殖水体中23种镇静剂

建立了同位素稀释-液相色谱-串联质谱法（LC-MS/MS）同时测定养殖水体中23种镇静剂残留的方法。样品经0.45 μm滤膜过滤后,用Oasis HLB固相萃取柱净化,浓缩后用50%的甲醇水定容。以1%甲酸水溶液和乙腈为流动相,采用Agilent InfiniityLab Poroshell 120 SB-C18色谱柱分离后,在多反应监测模式下测定,内标法定量。结果表明,23种镇静剂在0.5～100ng/L质量浓度范围内线性关系良好（r>0.99）,检出限和定量限分别为0.1~0.3和0.4 ~1.0 ng/L。加标回收率为73.5%~117.6%,相对标准偏差（RSD）为1.1%~9.9%。该方法前处理简单,净化效果较好,灵敏度较高,适用于池塘养殖水体中23种镇静剂类药物残留的快速检测。     

Combining steam injection with hydraulic fracturing for the in situ remediation of the unsaturated zone of a fractured soil polluted by jet fuel

A steam injection pilot-scale experiment was performed on the unsaturated zone of a strongly heterogeneous fractured soil contaminated by jet fuel. Before the treatment, the soil was stimulated by creating sub-horizontal sand-filled hydraulic fractures at three depths. The steam was injected through one hydraulic fracture and gas/water/non-aqueous phase liquid (NAPL) was extracted from the remaining fractures by applying a vacuum to extraction wells. The injection strategy was designed to maximize the heat delivery over the entire cell (10 m × 10 m × 5 m). The soil temperature profile, the recovered NAPL, the extracted water, and the concentrations of volatile organic compounds (VOCs) in the gas phase were monitored during the field test. GC-MS chemical analyses of pre- and post-treatment soil samples allowed for the quantitative assessment of the remediation efficiency. The growth of the heat front followed the configuration of hydraulic fractures. The average concentration of total hydrocarbons (g/kg of soil) was reduced by ～ 43% in the upper target zone (depth = 1.5-3.9 m) and by ～ 72% over the entire zone (depth = 1.5-5.5 m). The total NAPL mass removal based on gas and liquid stream measurements and the free-NAPL product were almost 30% and 2%, respectively, of those estimated from chemical analyses of pre- and post-treatment soil samples. The dominant mechanisms of soil remediation was the vaporization of jet fuel compounds at temperatures lower than their normal boiling points (steam distillation) enhanced by the ventilation of porous matrix due to the forced convective flow of air. In addition, the significant reduction of the NAPL mass in the less-heated deeper zone may be attributed to the counter-current imbibition of condensed water from natural fractures into the porous matrix and the gravity drainage associated with seasonal fluctuations of the water table.     

冰雪灾害对川南森林可燃物的影响

冰雪灾害是影响森林的一个重要气象干扰因素,并会引起生态系统中其他次生干扰。研究冰雪灾害对森林可燃物的影响,提出可行的灾后可燃物管理技术将为今后应对类似的极端气候事件提供科学依据。基于对川南典型森林雪灾后受损情况调查,定量分析雪灾对各类可燃物的影响。按不同森林类型和受灾强度测定林分基本特征和各类可燃物载量,地表可燃物载量调查采用线状相交可燃物调查方法。结果表明：森林受害程度与树种、林龄、海拔、地形等因素有关,针叶林和针阔混交林树冠受损程度为5%~45%,阔叶林树冠受损程度为3%~8%。雪灾引起的主要是较大径级可燃物载量显著增加,径级≥7.0cm的可燃物占可燃物增量的48%~100%。灾后阔叶林地表径级可燃物载量达1.75 kg/m2,其他林分为0.18kg/m2~0.55 kg/m2。雪灾还改变可燃物空间分布,大量断枝和折断树干增加了可燃物垂直分布连续性,地表火更容易发展为树冠火。受灾严重的林分郁闭度下降,也会引起林下草本增加,有利于火灾的发生与发展。建议对受灾林分的地表可燃物清理以人工或机械清理为主。     

国Ⅴ柴油机燃用丁醇-柴油混合燃料颗粒粒径分布特性试验研究

在一台不做任何改动的国Ⅴ共轨柴油机上,运用发动机排气颗粒数量和粒径分析仪EEPS,结合实测空燃比,在外特性以及最大转矩转速和额定转速两个不同转速的负荷特性下,对比研究了柴油机燃用不同体积分数(10%、15%、20%、30%、40%)的丁醇-柴油混合燃料(Bu10、Bu15、Bu20、Bu30、Bu40)和国Ⅴ柴油(D100)对排气颗粒数量浓度、质量浓度及颗粒数量浓度粒径分布特性的影响.结果表明,外特性下,随着转速的升高,丁醇-柴油混合燃料和纯柴油的颗粒数量浓度粒径分布都向单峰对数正态分布转变.随丁醇掺混比例的增加,核模态颗粒和小粒径聚集态颗粒排放数量浓度在各工况下都有不同程度的降低;大粒径聚集态颗粒数量排放在低速低负荷时会略有增加,而在高速高负荷时会略有降低或基本不变.掺混丁醇后,各工况的颗粒总数量浓度和总质量浓度都会降低,在高速高负荷时最明显.     

微氧环境中电化学活性微生物的分离与鉴定

电化学活性微生物在金属、碳等元素的生物地球化学循环,以及生物能源合成中具有重要作用.与微生物燃料电池厌氧阳极相比,微氧阳极能够捕集更多电能.但是相比于厌氧阳极中功能微生物的广泛研究,微氧阳极中的功能微生物还未被分离和研究.本研究采用传统好氧分离技术从微生物燃料电池微氧阳极分离获得3株纯菌Aeromonas sp.WS-XY2、Citrobacter sp.WS-XY3和Bacterium strain WS-XY4,其中WS-XY2和WS-XY3属于变形菌门,WS-XY4初步鉴定为新种.循环伏安、计时电流结果表明3株菌均具有电化学活性,且具有相似的直接胞外电子传递机制.3株菌在微生物分类学和电化学性质上的异同,表明微氧阳极能够定向筛选具有相似电化学性质的电化学活性微生物.微生物燃料电池微氧阳极具有更高效多样的功能微生物,可能是微氧阳极性能优于厌氧阳极的一个原因.因此,进一步针对微生物燃料电池微氧阳极中功能微生物的研究,将有助于阐明微氧阳极提高微生物燃料电池电能捕集的微生物机制.     

燃料油和原油乳化液在缢蛏（Sinonovacula constricta）体内的富集动力学研究

应用半静态双箱动力学模型在室内模拟了缢蛏(Sinonovacula constricta)对燃料油(0#柴油)和东海平湖原油乳化液的生物富集实验,通过对富集与释放过程中缢蛏体内石油烃的动态检测以及对检测结果的非线性曲线拟合,获得缢蛏对0#柴油、原油乳化液的吸收速率常数k1、释放速率常数k2、生物富集因子BCF、平衡状态下缢蛏体内石油烃含量C Amax、生物学半衰期B1/2等动力学参数.拟合结果得到的各动力学参数平均值分别为:缢蛏对0#柴油乳化液的吸收速率常数k1为10.67、k2为0.0795、BCF为122.56、C Amax为129.07 mg·kg-1、B1/2为9.61 d;缢蛏对原油乳化液的吸收速率常数k1为7.79、k2为0.0948、BCF为89.38、C Amax为110.68 mg·kg-1、B1/2为7.88 d.缢蛏对0#柴油、原油乳化液的吸收速率常数k1、BCF均随外部水体中石油烃浓度的增大而减少,对0#柴油、原油乳化液的释放速率常数k2与外部水体中石油烃浓度无明显相关性,C Amax随外部水体中石油烃浓度的增大而增大.对模型的拟合优度检验结果显示,模型的拟合优度良好.0#柴油在缢蛏体内的富集量高于原油乳化液、释放量低于原油乳化液,其原因与不同种类石油的烃类组分有关.     

Fluid Mechanics of Serpentine Flow Fields on a Porous Media

Laminar flows are investigated in single and double parallel serpentine channels mounted on a porous media and it is found that significant convective transport occurs in porous media for practical fuel cell conditions. This transport increases with increasing flow Reynolds number, with decreasing land width, and most significantly with increasing channel length.

Increasing the number of parallel channels significantly decreases the pressure drop across the fuel cell, but also significantly decreases the magnitude of convective transport in the porous media. Increased parasitic loads must be put in the context of the change in electrochemical performance.

This paper presents both data and a methodology for beginning to think about flow field design from a hydrodynamic perspective.     

Carbon‐neutral jet‐fuel re‐synthesised from sequestrated CO2

A chemical pathway combining reverse water gas shift, Fischer‐Tropsch synthesis and hydro‐cracking was considered to re‐synthesise jet fuel from CO₂ captured at high purity by oxy‐fuelling of a typical coal‐fired power station (Drax, UK). The oxygen for oxy‐fuelling and hydrogen for the fuel re‐synthesis process are sourced by electrolysis of water. According to material and energy balances , 3.1 MT/year of jet fuel and 1.6 MT/year each of gas oil and naphtha can be produced from the Drax annual emissions of 20 MT of CO₂, sufficient to supply 23% of the UK jet fuel requirements. The overall re‐synthesis requires 16.9 GW, to be sourced renewably from (offshore) wind power, and releases 4.4 GW of exothermic energy giving scope for improvements via process integration. The energy re‐synthesis penalty was 82% ideally and 95% on a practical basis. With the cost of offshore wind power predicted to reduce to 2.0 p/kWh by 2020, this ‘re‐syn’ jet fuel would be competitive with conventional jet fuel, especially if carbon taxes apply. The re‐use of CO₂ sequestrated from coal power stations to form jet‐fuel would halve the combined CO₂ emissions from the coal power and aviation sectors.     

硫酸盐对微生物燃料电池脱氮的影响

构建了双室型微生物燃料电池(MFC),探讨了硫酸盐对MFC阴极脱氮效果和产电性能的影响。实验结果表明:缺氧阴极室中,硝酸盐氮、硫酸盐的还原存在一定的竞争关系,且硫酸盐对电子的竞争能力比硝酸盐氮强;当S与N的质量比(记为S/N)为2∶1时,72 h后的硫酸根去除率达96.41%,而硝酸盐氮去除率仅为36.86%;在S/N为2∶1的条件下,当电压达307.6 m V时,功率密度达最大值15.77 W/m2,电池内阻为100Ω,与未加入硫酸盐时相比产电性能明显提高。     

Novel microbial fuel cell design to operate with different wastewaters simultaneously

A novel single cathode chamber and multiple anode chamber microbial fuel cell design(MAC-MFC)was developed by incorporating multiple anode chambers into a single unit and its performance was checked.During 60 days of operation,performance of MAC-MFC was assessed and compared with standard single anode/cathode chamber microbial fuel cell(SC-MFC).The tests showed that MAC-MFC generated stable and higher power outputs compared with SC-MFC and each anode chamber contributed efficiently.Further,MAC-MFCs were incorporated with different wastewaters in different anode chambers and their behavior in MFC performance was observed.MAC-MFC efficiently treated multiple wastewaters simultaneously at low cost and small space,which claims its candidature for future possible scale-up applications.