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高温真空炉连续测温解决方案探讨 被引量:2
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作者 吴智洪 《机电设备》 2013年第3期70-73,共4页
从高温真空炉的应用出发,阐述了高温真空炉温度测量的重要性。从自动控制的角度出发,说明了高温真空炉内温度连续测量的重要性。介绍了目前常用的高温真空炉温度测量法,并对现有的技术及方法进行了比较,分析了现有技术方法的局限性。通... 从高温真空炉的应用出发,阐述了高温真空炉温度测量的重要性。从自动控制的角度出发,说明了高温真空炉内温度连续测量的重要性。介绍了目前常用的高温真空炉温度测量法,并对现有的技术及方法进行了比较,分析了现有技术方法的局限性。通过介绍现有技术及提出新技术的理论分析和实践情况,说明了新方案解决高温真空炉长时间连续测温的可行性及合理性。 展开更多
关键词 高温真空炉 温度场 结晶 红外测温 金属挥发物
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Acid Volatile Sulfide and Simultaneously Extracted Metals in Tidal Flat Sediments of Jiaozhou Bay, China 被引量:3
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作者 ZHANG Xiangshang ZHANG Longjun 《Journal of Ocean University of China》 SCIE CAS 2007年第2期137-142,共6页
It is well known that acid-volatile sulfide (AVS) plays an important role in influencing the toxicity of divalent cationic metals within anoxic sediments. In studying sediment core samples collected from tidal flats w... It is well known that acid-volatile sulfide (AVS) plays an important role in influencing the toxicity of divalent cationic metals within anoxic sediments. In studying sediment core samples collected from tidal flats within the Jiaozhou Bay, China, we found that the AVS concentration gradually increases with depth and decreases from high tidal flat to low tidal flat areas. We evaluated the chemical activity and bioavailability of heavy metals in the tidal flat based on the molar ratio of simultaneously ex- tracted metals (SEM) and AVS. The value of SEM/AVS is generally less than 1 in this area except for the surface layer, which suggests that the heavy metals only have chemical activity in the surface layer. SEM is most highly concentrated at the boundary of the redox layer. SEM have similar depth distributions throughout the tidal flat. The aeration of low tidal flat sediment indicates that SEM gradually move to deeper sites via interstitial water. 展开更多
关键词 Jiaozhou Bay tidal flat acid volatile sulfide heavy metal
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Sodium-treated sepiolite-supported transition metal(Cu,Fe,Ni,Mn,or Co)catalysts for HCHO oxidation 被引量:5
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作者 Ning Dong Qing Ye +3 位作者 Mengyue Chen Shuiyuan Cheng Tianfang Kang Hongxing Dai 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 北大核心 2020年第11期1734-1744,共11页
Sodium-treated sepiolite(Na Sep)-supported transition metal catalysts(TM/Na Sep;TM = Cu, Fe, Ni, Mn, and Co) were synthesized via a rotary evaporation method. Physicochemical properties of the as-synthesized samples w... Sodium-treated sepiolite(Na Sep)-supported transition metal catalysts(TM/Na Sep;TM = Cu, Fe, Ni, Mn, and Co) were synthesized via a rotary evaporation method. Physicochemical properties of the as-synthesized samples were characterized by means of various techniques, and their catalytic activities for HCHO(0.2%) oxidation were evaluated. Among the samples, Cu/Na Sep exhibited superior performance, and complete HCHO conversion was achieved at 100 ℃(GHSV = 240000 m L/(g·h)). Additionally, the sample retained good catalytic activity during a 42 h stability test. A number of factors, including elevated acidity, the abundance of oxygen species, and favorable low-temperature reducibility, were responsible for the excellent catalytic activity of Cu/Na Sep. According to the results of the in-situ DRIFTS characterization, the HCHO oxidation mechanism was as follows:(i) HCHO was rapidly decomposed into dioxymethylene(DOM) species on the Cu/Na Sep surface;(ii) DOM was then immediately converted to formate species;(iii) the resultant formate species were further oxidized to carbonates;(iv) the carbonate species were eventually converted to CO2 and H2O. 展开更多
关键词 Sodium-treated sepiolite Transition metal loading Supported transition metal catalyst Volatile organic compound HCHO oxidation
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Design and synthesis of porous non-noble metal oxides for catalytic removal of VOCs 被引量:5
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作者 Wenxiang Tang Gang Liu +4 位作者 Dongyan Li Haidi Liu Xiaofeng Wu Ning Han Yunfa Chen 《Science China Chemistry》 SCIE EI CAS CSCD 2015年第9期1359-1366,共8页
The design and synthesis of highly active non-noble metal oxide catalysts, such as transition- and rare-earth-metal oxides, have attracted significant attention because of their high efficiency and low cost and the re... The design and synthesis of highly active non-noble metal oxide catalysts, such as transition- and rare-earth-metal oxides, have attracted significant attention because of their high efficiency and low cost and the resultant potential applications for the degradation of volatile organic compounds(VOCs). The structure-activity relationships have been well-studied and used to facilitate design of the structure and composition of highly active catalysts. Recently, non-noble metal oxides with porous structures have been used as catalysts for deep oxidation of VOCs, such as aromatic hydrocarbons, aliphatic compounds, aldehydes, and alcohols, with comparable activities to their noble metal counterparts. This review summarizes the growing literature regarding the use of porous metal oxides for the catalytic removal of VOCs, with emphasis on design of the composition and structure and typical synthetic technologies. 展开更多
关键词 VOCS catalytic oxidation non-noble metal oxides structure-activity relationships synthetic methods
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Scalable arrays of chemical vapor sensors based on DNA-decorated graphene 被引量:3
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作者 Nicholas J. Kybert Gang Hee Han +3 位作者 Mitchell B. Lerner Eric N. Dattoli Ali Esfandiar A. T. Charlie Johnson 《Nano Research》 SCIE EI CAS CSCD 2014年第1期95-103,共9页
Arrays of chemical vapor sensors based on graphene field effect transistors functionalized with single-stranded DNA have been demonstrated. Standard photolithographic processing was adapted for use on large-area graph... Arrays of chemical vapor sensors based on graphene field effect transistors functionalized with single-stranded DNA have been demonstrated. Standard photolithographic processing was adapted for use on large-area graphene by including a metal protection layer, which protected the graphene from contamination and enabled fabrication of high quality field-effect transistors (GFETs). Processed graphene devices had hole mobilities of 1,640 ± 250 cm2.V-1.s-1 and Dirac voltages of 15 ± 10 V under ambient conditions. Atomic force microscopy was used to verify that the graphene surface remained uncontaminated and therefore suitable for controlled chemical functionalization. Single-stranded DNA was chosen as the functionalization layer due to its affinity to a wide range of target molecules and π-π stacking interaction with graphene, which led to minimal degradation of device characteristics. The resulting sensor arrays showed analyte- and DNA sequence-dependent responses down to parts-per-billion concentrations. DNA/GFET sensors were able to differentiate among chemically similar analytes, including a series of carboxylic acids, and structural isomers of carboxylic acids and pinene. Evidence for the important role of electrostatic chemical gating was provided by the observation of understandable differences in the sensor response to two compounds that differed only by the replacement of a (deprotonating) hydroxyl group by a neutral methyl group. Finally, target analytes were detected without loss of sensitivity in a large background of a chemically similar, volatile compound. These results motivate further development of the DNA/graphene sensor family for use in an electronic olfaction system. 展开更多
关键词 GRAPHENE vapor sensor DNA PHOTOLITHOGRAPHY chemical gating
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