Effect of ceria addition on NiRu/CeO2Al2O3 catalysts in steam reforming of acetic acid

NiRu bimetallic catalysts with different amount of CeO₂ loaded on the γ-Al₂O₃ support were prepared. The properties of catalysts were characterized by means of N₂ adsorption-desorption, XRD, H₂-TPR and XPS techniques. Catalytic activities for the steam reforming of acetic acid over these catalysts were investigated at the temperature range from 650 °C to 750 °C. The addition of CeO₂ dramatically improved the activity and stability of the catalyst. Among these catalysts, the NiRu/10CeAl catalyst showed the highest catalytic activity as well as a good stability owing to the abundant Ce³⁺ on the surface of catalyst. The existence of Ce³⁺ promoted the formation of CO₂ from CO because of the mobilizable oxygen, which was favorable for the formation of hydrogen. The coke amount and species deposited on the catalysts after the activity tests were analyzed by DTG. As expected, the NiRu/10CeAl catalyst showed the best resistance to carbon formation. The temperature stepwise steam decoking experiment of the spent catalysts was conducted to elucidate the relationship between the existence of Ce³⁺ and the decoking abilities of various catalysts. It was verified that the existence of Ce³⁺ significantly promoted the decoking abilities of the catalysts.     

亲水拒油含氟整理剂的合成及其在棉织物上的应用

以F113和全氟聚醚酰氟为原料,合成了全氟聚醚二酰基过氧化物,并用来引发二甲基二烯丙基氯化铵聚合,得到含有全氟烷氧基(末端基团)的二甲基二烯丙基氯化铵聚合物Pf通过传统的轧-烘-焙过程将其整理到棉织物上.通过测试水和正十二烷在整理后织物上的接触角对该聚合物的亲水拒油性能进行评价.结果表明:聚合物Pf具有良好的亲水拒油性,对水的接触角为0°,对正十二烷的接触角为116.3°,同时整理后的棉织物具有很好的亲水拒油耐洗性.     

树脂对大豆异黄酮吸附与洗脱性能的研究

利用HPD-600大孔吸附树脂对大豆异黄酮的吸附与洗脱性能进行了研究.测定其静态吸附率为53.30%,静态解吸率为95.36%.吸附时间2 h时,吸附基本达到最大,解吸时间为2.4h时,解吸基本达到最大.上样量45mL时,吸附效果最佳.经吸附-解吸和干燥后,产品纯度达到39.7%.     

Concentrations and composition profiles of benzotriazole UV stabilizers in municipal sewage sludge in China

The environmental contamination and fate of benzotriazole UV stabilizers (BZTs) have received increasing attention due to their large production volume and wide usage in various consumer and industrial products. In the present work, 60 municipal sewage sludge samples from wastewater treatment plants (WWTPs) in 33 cities in China were collected to investigate the occurrence and distribution of 9 frequently used BZTs. The most dominant analogue was 2-[3,5-bis(1-methyl-1-phenylethyl)-2-hydroxyphenyl]benzotriazole (UV-234) at a median concentration of 116 ng/g (dry weight) and accounted on average for 27.2% of total BZTs. The abundance was successively followed by 2-(2-hydroxy-5-tert-octylphenyl)benzotriazole (UV-329, average 24.3%), 2-(2-hydroxy-3-tert-butyl-5-methylphenyl)-5-chlorobenzotriazole (UV-326, average 22.2%), 2-(3,5-di-tert-amyl-2-hydroxyphenyl)benzotriazole (UV-328, average 17.7%), and 2-(2-hydroxy-5-methylphenyl)benzotriazole (UV-P, average 6.6%), with median concentrations of 66.8, 67.8, 57.3, and 20.6 ng/g, respectively. 5-Chloro-2-(3,5-di-tert-butyl-2-hydroxyphenyl)benzotriazole (UV-327) and 2-(3-sec-butyl-5-tert-butyl-2-hydroxyphenyl)benzotriazole (UV-350) had low detection frequency, while 2-(3,5-di-tert-butyl-2-hydroxyphenyl)benzotriazole (UV-320) and 2-(5-tert-butyl-2-hydroxyphenyl)benzotriazole (UV-PS) were not detectable in any sample. To our knowledge, this is the first study reporting the occurrence of UV-234, UV-329, and UV-350 in sewage sludge in China. Significant correlations were found among the BZT concentrations and also with a WWTP characteristic (daily treatment volume). Furthermore, results from degradation prediction and multimedia fate simulation based on a quantitative structure-property relationship (QSPR) model at screening level also implied that the commercial BZT chemicals and their plausible transformation products might be persistent in the environment.     

不同发酵温度和浸渍时间对红葡萄酒理化指标的影响

本文研究了葡萄酒发酵过程中不同发酵温度和浸渍时间对葡萄酒理化指标的影响。温度控制在24～26℃,26～28℃,28～30℃;浸渍时间控制在5d,7d和10d。结果表明,当发酵温度在24～26℃时有利于葡萄酒酒精的转化和色素的浸出;在浸渍时间为7d时有利于对葡萄酒的色素和酚类物质的浸提。因此,发酵温度24～26℃为葡萄酒发酵最适温度;浸渍时间7d为葡萄酒最适浸渍时间。     

工业硫磺中低含量砷的测定

用ＧＢ２４４９－９２规定的二乙基二硫代氨基甲酸解光度法测定硫磺中的砷含量,并对测定方法进行了改进,减少了工作曲线中砷标准溶液取样量,将砷的最小检知量由ＧＢ２４４９－９２规定的ｗ＝０．０００％降低到ｗ＝０．００００１％取得了较好的效果。     

对NOTRUMP-AP600程序缺少动量通量项的评估与修正

由于NOTRUMP-AP600程序的动量守恒方程缺少动量通量项,在分析用于模拟AP600核电厂的APEX试验台架小破口事故时,安全壳内置换料水箱注射流量和稳压器混合水位等参数的预测值和实验值有较大偏离。本文对此进行评估：1) 采用均相流和分相流模型计算动量通量项对AP600核电厂自动卸压系统（ADS）管路压降的影响;2) 采用FLOAD4程序对需修正的第4级ADS(ADS4)管路的两相流压降进行计算,预测ADS4管路内的压力分布,并用作修正NOTRUMP-AP600程序ADS4管路压降的基准。结果表明,对于AP600核电厂ADS4管路,输入阻力系数需增加60%。     

Experimental investigation on thermal performance of thermosyphon flat-plate solar water heater with a mantle heat exchanger

The thermal performance of thermosyphon flat-plate solar water heater with a mantle heat exchanger was investigated to show its applicability in China. The effect on the performance of the collector of using a heat exchanger between the collector and the tank was analyzed. A “heat exchanger penalty factor” for the system was determined and energy balance equation in the system was presented. Outdoor tests of thermal performance of the thermosyphon flat-plate solar water heater with a mantle heat exchanger were taken in Kunming, China. Experimental results show that mean daily efficiency of the thermosyphon flat plate solar water heater with a mantle heat exchanger with 10 mm gap can reach up to 50%, which is lower than that of a thermosyphon flat-plate solar water heater without heat exchanger, but higher than that of a all-glass evacuated tubular solar water heater.     

Electrochemical evolution of hydrogen on composite La–Ni–Al/Ni–S alloy film in water electrolysis

The composite La–Ni–Al/Ni–S alloy film was obtained by molten salt electrolysis and aquatic electrodeposition in turn. The La–Ni–Al alloy film was prepared in Na₃AlF₆–La₂O₃–Al₂O₃ molten salt electrolyte by galvanostatic electrolysis at 100 mA cm^?2. The results showed that La³⁺ and Al³⁺ ions could be co-reduced on the nickel cathode and form La–Ni–Al film at c.a. ?0.5 V, which is much lower than that of the theoretical decomposition potential of lanthanum and aluminum. With high HER activity, the composite La–Ni–Al/Ni–S film (η₁₅₀ = 70 mV, 353 K) could absorb large amount of H atoms. Instead of the dissolution of the Ni–S film, the absorbed H atoms would be oxidized under intermittent electrolysis effectively and prolong the lifetime of the cathode.