Effect of chromium oxide as active site over TiO2-PILC for selective catalytic oxidation of NO

This study introduced TiO2-pillared clays （TiO2-PILC） as a support for the catalytic oxidation of NO and analyzed the performance of chromium oxides as the active site of the oxidation process. Cr-based catalysts were prepared by a wet impregnation method. It was found that the 10 wt.% chromium doping on the support achieved the best catalytic activity. At 350℃, the NO conversion was 61% under conditions of GHSV = 23600 hr^-l. The BET data showed that the support particles had a mesoporous structure. Hz-TPR showed that Cr（10）TiP （10 wt.% Cr doping on TiO2-PILC） clearly exhibited a smooth single peak. EPR and XPS were used to elucidate the oxidation process. During the NO ＋ O2 adsorption, the intensity of evolution of superoxide ions （O2^-） increased. The content of Cr^3＋ on the surface of the used catalyst was 40.37%, but when the used catalyst continued adsorbing NO, the Cr^3＋ increased to 50.28%. Additionally, Oα/Oβ increased markedly through the oxidation process. The NO conversion decreased when SO2 was added into the system, but when the SO2 was removed, the catalytic activity recovered almost up to the initial level. FT-IR spectra did not show a distinct characteristic peak of SO4^2-.     

太湖梅梁湾有色可溶性有机物对光的吸收

探讨了太湖梅梁湾不同湖区有色可溶性有机物(CDOM)对光的吸收、光衰减系数的变化及与DOC浓度的关系、CDOM吸收对光衰减系数的贡献率以及指数函数曲线斜率S值.结果表明,不同类型湖区CDOM吸收系数差异明显,a_d(440)、a_d(320)的变化范围分别为1.22～2.58m^-1,6.24～10.69m^-1;DOC浓度最高值出现在梁溪河口,为12.74mg/L,最低值出现梅梁湾口,为6.87mg/L,大致呈由湾内向湾口逐渐递减的趋势;DOC与CDOM吸收系数在波长320nm以下存在显著性相关,波长320～700nm CDOM吸收对光衰减系数的贡献率在0.69%～60.9%间变化,400nm以下紫外短光部分贡献率均大于20%,空间上短波部分贡献率在河口区、五里湖比梅梁湾内及沿岸带要大;CDOM吸收的指数函数曲线斜率S在13.9～18.1m^-1间.     

基于电化学噪声技术的碳钢大气腐蚀行为监测方法

目的基于电化学噪声技术搭建了Q235碳钢腐蚀行为监测系统,对海洋大气环境下Q235碳钢的腐蚀过程进行监测。方法采用时域谱图、频域谱图方法对采集的电化学噪声数据进行分析。结果 0.5~2.0 h(晴天),电流噪声幅值较小,时域谱图出现少数暂态峰,频域谱图无白噪声区,电极处于钝化期;46~47.5 h(降雨),电流噪声波动变大,谱图出现大量暂态峰,PSD的斜率快速下降,电极表面出现蚀点,电极处于稳态点蚀期。结论该监测系统很好地实现了对海洋大气下Q235碳钢腐蚀行为的连续监测。     

含盐水体中酪氨酸的光致溴代反应研究

选取溶解性有机质中小分子酪氨酸(Tyr)作为研究对象,研究了含盐水体中Tyr的光降解及溴代转化.同时,探讨了pH值及天然水体中广泛存在的Fe(III)对Tyr光转化的影响.结果表明,汞灯照射下(λ290 nm),在含14.56 mg·L-1Fe(Ⅲ)的溴离子溶液中(pH=3.0),检测到Tyr(C0,Tyr=0.40 mg·L-1)反应0.5 h过程中产生了3-溴-酪氨酸(3-Br Tyr,15.97μg·L~(-1))和3,5-二溴-L-酪氨酸(3,5-di Br Tyr,10.45μg·L~(-1))两种溴代产物.在pH=3.0~8.0范围内,Tyr光降解速率随pH值升高而降低;3-Br Tyr和3,5-di Br Tyr的形成量随pH升高而减少;而在pH=3.0时,Tyr光降解速率、3-Br Tyr和3,5-di Br Tyr形成量随Fe(Ⅲ)浓度的增加而增加.这说明在自然环境中,Tyr能通过光转化形成溴代有机污染物.     

UV-B辐射增强与O3胁迫对冬小麦光合特征的影响

为探明UV-B和O3复合胁迫对冬小麦光合作用的影响,开展了UV-B和O3单因子及其复合的大田开顶式气室（OTC）试验（CK,自然空气和UV-B辐射强度;T1,O3含量100 nmol.mol-1±9 nmol.mol-1;T2,UV-B辐射强度相对CK增加10%～10.9%;T3,复合处理组）,利用LCpro＋光合仪和...     

Characteristics of NO reduction with non-thermal plasma

As a new type of NO removal system, NO reduction in N2-NO plasma was applied to solve the difficulties in the traditional methods, such as higher energy-consumption, larger equipment size and high cost, and so on. Using the experimental NO reduction system with single-pair electrode tip discharge structure, the NO reduction characteristics of N~-NO system were revealed to guide the engineering practice; the results of NO reduction with single-pair electrode tip discharge plasma also have the same instructive meaning to the NO reduction with multi-pair electrode tip discharge plasma. The amount of both active N atom and NO removal rate increased with the distance /g increasing between the two electrode tips and then dropped when the distance exceeded a certain value. The NO removal rate increased while the voltage between two electrode tips or the resident time of gas flow increased. The distance is a key geometrical variable factor that can determine the intensity of electric field between two electrode tips and the resident time of gas. In this paper, the effects of the dielectric features on NO reduction using dielectric-barrier discharge plasma system were also studied. The results of NO removal rate with different dielectrics such as Al2O3, CaO. MgO and glass showed that the electric field intensity is different with different dielectric, because it brings different energy to particles in discharge room and thus it causes different NO removal rate.     

光芬顿法处理次磷酸盐同步回收磷性能及参数研究

本研究构建了以模拟太阳光(AM 1.5,100 mW·cm^-2)为光源的光芬顿体系，研究了对化学镀镍废水中次磷酸盐(H₂PO₂^-)的氧化且同步回收磷(P)，比较了单独H₂O₂、模拟太阳光和H₂O₂联用、H₂O₂与FeSO₄联用(芬顿法)、模拟太阳光和芬顿法联用(光芬顿法)对H₂PO₂^-的氧化效果.结果表明光芬顿法效果最优，能够高效氧化H₂PO₂^-为PO₄^-的同时在一定条件下以磷酸铁(FePO₄)沉淀形式回收P.考察了不同H₂O₂浓度、H₂O₂投加次数、溶液初始pH值、...     

光质对小球藻(Chlorella sorokiniana)生长和代谢机制的调控

为研究光质对小球藻(Chlorella sorokiniana)生长和代谢机制的影响,分析了不同光质下C. sorokiniana的生长情况,利用Illumina平台进行转录组测序.结果表明:红､蓝光是C. sorokiniana生长的有效光质,红､蓝光培养7d后藻细胞密度分别比白光对照组的高52.96%和61.11%.C. sorokiniana在不同光质下具有独特的生理特性,蓝光组Chl a､Chl b和Car最高,分别为(17.84±0.26), (8.39±0.19), (6.04±0.08) mg/L;红光培养7d后微藻的碳水化合物和脂质含量最高,分别达到了(115.60±1.81)μg/mg和(18.64±0.54)%.通过转录组测序分析,不同光质下C. sorokiniana的基因表达存在差异,红光下碳酸酐酶､乙酰辅酶A羧化酶和脂肪酸合成酶的基因表达量较高,差异表达的基因大部分参与了脂肪酸合成和碳固定过程;蓝光下RubisCO酶的基因表达量最高且光合系统中富集的差异基因均上调表达,光合速率和碳固定速率最快;绿光下微藻大部分的基因表达量较低,新陈代谢潜能较差;白光下C. sorokiniana的TCA循环活跃,不利于储存碳水化合物和脂质.     

飞机货舱锂离子电池火灾烟雾光散射特性

锂离子电池应用广泛，飞机货舱内不可避免地会运载锂离子电池或含有锂离子电池的货物，导致货舱内锂离子电池火灾时有发生。然而，研究者对飞机货舱感烟火灾探测器是否适用于锂离子电池火灾及响应性能的认识尚不清楚。航空标准SAE AS8036A是为测试和评估飞机货舱感烟火灾探测器性能而制定的，其中仅规定了几种标准测试火，并没有锂离子电池火灾相关内容。使用SAE AS8036A标准中规定的试验装置，研究了两种荷电状态的18650锂离子电池火灾烟雾光散射特性，并选取SAE AS8036A标准中规定的2种阴燃烟雾、2种明火烟雾及2种粉尘干扰气溶胶作为对比。结果表明，设计的探测器模型采用两种波长入射光(405 nm、850 nm)及两个散射角(45°、135°)光电二极管，能区分识别火灾烟雾与粉尘干扰气溶胶，并且判断是否为锂离子电池火灾。     

多环芳烃光动力降解产物的细胞毒性检验

对多环芳烃的光动力降解产物进行细胞毒性评价，将8种多环芳烃(菲、蒽、萘、■、荧蒽、苯并[a]芘、苯并[k]荧蒽和苯并[a]蒽)水溶液分为对照组和光动力试验组，分别与小鼠成纤维细胞L929细胞系共培养一段时间，通过倒置显微镜观察细胞形态的变化，磺酰罗丹明B试验计算细胞存活率，根据细胞核染色和Annexin V-FITC/PI染色配合流式细胞仪分析细胞凋亡情况来综合评价多环芳烃的光动力降解产物的细胞毒性。结果表明：经倒置显微镜观察，光动力试验组的死细胞数量变少；在25.0 ng/mL、12.5 ng/mL、3.1 ng/mL和1.6 ng/mL下，细胞存活率较之对照组分别增高了21.35%、20.22%、20.22%和20.23%;经细胞核染色发现，在50.0 ng/mL和25.0 ng/mL下，光动力试验组的细胞凋亡率分别为40%和14%,较之对照组明显降低；经Annexin V-FITC/PI染色及流式细胞仪分析，在50.0 ng/mL下，光动力试验组的细胞凋亡率比对照组降低了32.67%。试验结果证实了多环芳烃的光动力降解产物较之未降解的多环芳烃的细胞毒性降低。