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An effective gas-liquid chromatographic separation of thirteen energetic dicyclopentadiene derivatives has been established using OV-17 as the stationary phase. FID was chosen as the favorable detector after comparing its response factors with those of TCD. Using this method good repeatability, reproducibility and precision are obtained in both qualitative and quantitative analyses of compounds investigated. 相似文献
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Summary A gas chromatography-mass spectrometric assay method was developed for the simultaneous determination of 2,6-di-tert-butylphenol (DTBP) and 2,4-dimethyl-6-tert-butylphenol (DMTBP) in aviation fuel. Extraction and purification were achieved with a solid phase extraction procedure using silica gel. Elution was performed with 30 mL of methylene chloride: pentane (2:3) following washing with 10 mL of n-pentane. The extract was concentrated to about 100 L and analyzed by GC-MS (SIM). The peaks had good chromatographic properties by using a semi-polar column (Innowax) and the extraction of these compounds from samples gave recoveries of about 87% for DTBP and about 75% for DMTBP with small variations. Method detection limits were 5.0 ng mL–1 for DBMP and 7.0 ng mL–1 for DMTBP. The method may be useful for spilled fuel type differentiation between kerosene and JP-8. 相似文献
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Dr. Nicola Armaroli Prof. Dr. Vincenzo Balzani 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(1):32-57
The energy transition from fossil fuels to renewables is already ongoing, but it will be a long and difficult process because the energy system is a gigantic and complex machine. Key renewable energy production data show the remarkable growth of solar electricity technologies and indicate that crystalline silicon photovoltaics (PV) and wind turbines are the workhorses of the first wave of renewable energy deployment on the TW scale around the globe. The other PV alternatives (e.g., copper/indium/gallium/selenide (CIGS) or CdTe), along with other less mature options, are critically analyzed. As far as fuels are concerned, the situation is significantly more complex because making chemicals with sunshine is far more complicated than generating electric current. The prime solar artificial fuel is molecular hydrogen, which is characterized by an excellent combination of chemical and physical properties. The routes to make it from solar energy (photoelectrochemical cells (PEC), dye‐sensitized photoelectrochemical cells (DSPEC), PV electrolyzers) and then synthetic liquid fuels are presented, with discussion on economic aspects. The interconversion between electricity and hydrogen, two energy carriers directly produced by sunlight, will be a key tool to distribute renewable energies with the highest flexibility. The discussion takes into account two concepts that are often overlooked: the energy return on investment (EROI) and the limited availability of natural resources—particularly minerals—which are needed to manufacture energy converters and storage devices on a multi‐TW scale. 相似文献
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Over the last several years,the need to find clean and renewable energy sources has increased rapidly because current fossil fuels will not only eventually be depleted,but their continuous combustion leads to a dramatic increase in the carbon dioxide amount in atmosphere.Utilisation of the Sun’s radiation can provide a solution to both problems.Hydrogen fuel can be generated by using solar energy to split water,and liquid fuels can be produced via direct CO2 photoreduction.This would create an essentially free carbon or at least carbon neutral energy cycle.In this tutorial review,the current progress in fuels’ generation directly driven by solar energy is summarised.Fundamental mechanisms are discussed with suggestions for future research. 相似文献
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Xue Yang Bing Yan Hai-feng Xu Rui-han Zhu Mei-xia Zhang Da-jun Ding 《化学物理学报(中文版)》2013,(5):519-525,I0003
The potential energy surfaces for butanone isomerization have been investigated by density function theory calculation. Six main reaction pathways are confirmed using the intrinsic reaction coordinate method, and the corresponding isomerization products are 1-buten-2-ol, 2-buten-2-ol, butanal or 1-buten-l-ol, methyl 1-propenyl ether, methyl allyl ether, and ethyl vinyl ether, respectively. Among them, there are three pathways through butylene oxide, indicating butylene oxide is an important intermediate product during butanone isomer ization. The calculated vertical ionization energies of the reactant and its products are in a good agreement with the experimental values available. From the consideration for the relative energies Of transition states and the number of high-energy barriers we infer that the reaction pathway butanone-*l-buten-2-ol---2-buten-2-oi is the most competitive. The obtained results are informative for future studies on isomerization of ketone molecules. 相似文献
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Modern methods of recycling organic waste are not considered viable today. Therefore, an important advantage of the proposed technology is to obtain mineral fuel products as an output. The technologies of high-temperature processing are based on thermal decomposition of waste without oxygen at high temperature. In pyrolysis, wastes are converted into gaseous, liquid and solid fuels. Thereby, the properties and composition of the liquid feedstock obtained by pyrolysis with a boiling temperature in the range of X.I. (38) - 180 °C, 180 - 320 °C and more than 320 °C were investigated. Residue with a boiling temperature over 320° C (52.4% vol.) is the main portion of the synthetic liquid fuels (SLF). It can be attributed to fuel oil grade 100 and used as boiler fuel or fuel oil additives according to the studied physicochemical parameters. 相似文献
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Novel Method for Preparation of Polypropylene Blends with High Melt Strength by Reactive Compounding
Ultrafine full-vulcanized polybutadiene rubber(UFBR) with particle sizes of ca.50―100 nm were used for modifying mechanical and processing performances of polypropylene(PP) with PP-g-maleic anhydride(PP-g-MA) as a compatibilizer for enhancing the interfacial adhesion between the two components.The morphology,dynamical rheology response and mechanical properties of the blends were characterized by means of SEM,rheometer and tensile test,respectively.The results show that the ternary PP/UFBR blends compatibil... 相似文献
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有关小分子醇、H。和CO等易燃气体在铂催化下的高温燃烧的温度振荡及以表面活性剂为关键组分的液膜扩散振荡已有报道"-'-.但由界面膜作用而产生的乳化燃油燃烧中的振荡反应尚无其它可操作的原始研究文献,只是在前文['j中提及过出现该现象.为了解乳化燃油燃烧过程中界面变化及其对燃烧的作用,通过静态燃烧实验配方的调节及变换以改变燃烧界面的情况.实验发现,在乳化燃油中加入一般的食用豆油,并使之水解出长链竣酸盐,则富集在燃烧界面上的长链竣酸盐所形成的界面膜对燃烧的自阻抑作用便会产生明显的振荡反应,形成火焰温度与高… 相似文献
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Guangbo Chen Geoffrey I. N. Waterhouse Run Shi Jiaqing Zhao Zhenhua Li Li‐Zhu Wu Chen‐Ho Tung Tierui Zhang 《Angewandte Chemie (International ed. in English)》2019,58(49):17528-17551
Catalytic C1 chemistry based on the activation/conversion of synthesis gas (CO+H2), methane, carbon dioxide, and methanol offers great potential for the sustainable development of hydrocarbon fuels to replace oil, coal, and natural gas. Traditional thermal catalytic processes used for C1 transformations require high temperatures and pressures, thereby carrying a significant carbon footprint. In comparison, solar‐driven C1 catalysis offers a greener and more sustainable pathway for manufacturing fuels and other commodity chemicals, although conversion efficiencies are currently too low to justify industry investment. In this Review, we highlight recent advances and milestones in light‐driven C1 chemistry, including solar Fischer–Tropsch synthesis, the water‐gas‐shift reaction, CO2 hydrogenation, as well as methane and methanol conversion reactions. Particular emphasis is placed on the rational design of catalysts, structure–reactivity relationships, as well as reaction mechanisms. Strategies for scaling up solar‐driven C1 processes are also discussed. 相似文献
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一种制备用于正庚烷异构化的Pt-WO3/ZrO2催化剂的新方法 总被引:3,自引:0,他引:3
采用不同的ZrO(OH)2前驱体制备了WO3-ZrO2和Pt/WO3-ZrO2催化剂. 结果表明,与常规的ZrO(OH)2水凝胶为前驱体制备的WO3-ZrO2-CP催化剂相比,以常压流动氮气中干燥处理的ZrO(OH)2乙醇凝胶为前驱体制备的WO3-ZrO2-AN催化剂对正庚烷临氢异构化反应具有更高的催化活性. 当在 WO3-ZrO2-AN中添加少量Pt时,其催化活性和稳定性均得到显著提高. 表明以ZrO(OH)2醇凝胶为前驱体可以制备出高效稳定的Pt/WO3-ZrO2-AN催化剂. 相似文献
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Competition between H and CO for Active Sites Governs Copper‐Mediated Electrosynthesis of Hydrocarbon Fuels 下载免费PDF全文
Dr. Marcel Schreier Dr. Youngmin Yoon Megan N. Jackson Prof. Yogesh Surendranath 《Angewandte Chemie (International ed. in English)》2018,57(32):10221-10225
The dynamics of carbon monoxide on Cu surfaces was investigated during CO reduction, providing insight into the mechanism leading to the formation of hydrogen, methane, and ethylene, the three key products in the electrochemical reduction of CO2. Reaction order experiments were conducted at low temperature in an ethanol medium affording high solubility and surface‐affinity for carbon monoxide. Surprisingly, the methane production rate is suppressed by increasing the pressure of CO, whereas ethylene production remains largely unaffected. The data show that CH4 and H2 production are linked through a common H intermediate and that methane is formed through reactions among adsorbed H and CO, which are in direct competition with each other for surface sites. The data exclude the participation of solution species in rate‐limiting steps, highlighting the importance of increasing surface recombination rates for efficient fuel synthesis. 相似文献
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反相高效液相色谱法测定高能发射药中5种组分 总被引:1,自引:0,他引:1
提出了反相高效液相色谱法测定高能发射药中5种组分硝化甘油(NG)、黑索今(RDX)、硝基胍(NQ)、Ⅱ号中定剂(C2)和邻苯二甲酸二正辛酯(DOP)的含量。试样溶解后进行色谱分离,采用Agilent色谱柱(150mm×4.6mm,5μm),流动相为甲醇-水(60+40)混合溶液(用于分离NG、RDX、NQ和C2)和甲醇-水(95+5)混合溶液(用于分离DOP),在波长220nm处进行测定。NG的质量浓度在0.42~4.08g.L-1,RDX在1.41~5.04g.L-1,NQ在1.11~3.74g.L-1,C2在0.07~0.90g.L-1,DOP在0.08~0.37g.L-1时分别与其峰面积呈线性关系。5种化合物的加标回收率在99.3%~101.9%之间;相对标准偏差(n=6)在0.19%~3.1%之间。 相似文献
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Lee R. Webster Dr. Saad K. Ibrahim Dr. Joseph A. Wright Prof. Christopher J. Pickett 《Chemistry (Weinheim an der Bergstrasse, Germany)》2012,18(37):11798-11803
We show that a robust molybdenum hydride system can sustain photoelectrocatalysis of a hydrogen evolution reaction at boron‐doped, hydrogen‐terminated, p‐type silicon. The photovoltage for the system is about 600–650 mV and the current densities, which can be sustained at the photocathode in non‐catalytic and catalytic regimes, are similar to those at a photoinert vitreous carbon electrode. The kinetics of electrocatalysed hydrogen evolution at the photocathode are also very similar to those measured at vitreous carbon—evidently visible light does not significantly perturb the catalytic mechanism. Importantly, we show that the doped (1–10 Ω cm) p‐type Si can function perfectly well in the dark as an ohmic conductor and this has allowed direct comparison of the cyclic voltammetric behaviour of the response of the system under dark and illuminated conditions at the same electrode. The p‐type Si we have employed optimally harvests light energy in the 600–700 nm region and with 37 mW cm?2 illumination in this range; the light to electrochemical energy conversion is estimated to be 2.8 %. The current yield of hydrogen under broad tungsten halide lamp illumination at 90 mW cm?2 is (91±5) % with a corresponding chemical yield of (98±5) %. 相似文献
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Lithium ion batteries (LIBs) have broad applications in a wide variety of a fields pertaining to energy storage devices. In line with the increasing demand in emerging areas such as long-range electric vehicles and smart grids, there is a continuous effort to achieve high energy by maximizing the reversible capacity of electrode materials, particularly cathode materials. However, in recent years, with the continuous enhancement of battery energy density, safety issues have increasingly attracted the attention of researchers, becoming a non-negligible factor in determining whether the electric vehicle industry has a foothold. The key issue in the development of battery systems with high specific energies is the intrinsic instability of the cathode, with the accompanying question of safety. The failure mechanism and stability of high-specific-capacity cathode materials for the next generation of LIBs, including nickel-rich cathodes, high-voltage spinel cathodes, and lithium-rich layered cathodes, have attracted extensive research attention. Systematic studies related to the intrinsic physical and chemical properties of different cathodes are crucial to elucidate the instability mechanisms of positive active materials. Factors that these studies must address include the stability under extended electrochemical cycles with respect to dissolution of metal ions in LiPF6-based electrolytes due to HF corrosion of the electrode; cation mixing due to the similarity in radius between Li+ and Ni2+; oxygen evolution when the cathode is charged to a high voltage; the origin of cracks generated during repeated charge/discharge processes arising from the anisotropy of the cell parameters; and electrolyte decomposition when traces of water are present. Regulating the surface nanostructure and bulk crystal lattice of electrode materials is an effective way to meet the demand for cathode materials with high energy density and outstanding stability. Surface modification treatment of positive active materials can slow side reactions and the loss of active material, thereby extending the life of the cathode material and improving the safety of the battery. This review is targeted at the failure mechanisms related to the electrochemical cycle, and a synthetic strategy to ameliorate the properties of cathode surface locations, with the electrochemical performance optimized by accurate surface control. From the perspective of the main stability and safety issues of high-energy cathode materials during the electrochemical cycle, a detailed discussion is presented on the current understanding of the mechanism of performance failure. It is crucial to seek out favorable strategies in response to the failures. Considering the surface structure of the cathode in relation to the stability issue, a newly developed protocol, known as surface-localized doping, which can exist in different states to modify the surface properties of high-energy cathodes, is discussed as a means of ensuring significantly improved stability and safety. Finally, we envision the future challenges and possible research directions related to the stability control of next-generation high-energy cathode materials. 相似文献