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Zhong R.,China University of PetroleumBeijing | Yu X.,China University of PetroleumBeijing | Zou R.,Peking University
Inorganic Chemistry Communications | Year: 2015

A new lanthanide-organic framework formulated as TbL 1 (H3L = 9-(4-carboxy-phenyl)-9H-carbazole-3,6-dicarboxylic acid), was synthesized under hydrothermal reaction condition. Single-crystal X-ray diffraction analysis shows that 1 crystallizes in a hexagonal P65 space group with three-dimensional network and microporous structure. The desolventized framework of 1 shows much higher uptake of CO2 (43.7 cm3 g-1) than that of CH4 (15.1 cm3 g-1) at 1 atm and 273 K, which makes it a potential candidate for CO2/CH4 separation. © 2015 Published by Elsevier B.V.

Zhu Q.,China University of PetroleumBeijing | Jiang G.,China University of PetroleumBeijing | Riggs J.M.,University of California at Los Angeles
Materials Letters | Year: 2016

Core/shell structured SrFe12O19/FeCo particles were synthesized through a microwave-polyol process. The magnetic exchange coupling between SrFe12O19 and FeCo was investigated by magnetic hysteresis loop and Henkel plot. Compared with electric plate heating, which is reported to result in SrFe12O19 loss during the reaction, microwave heating requires shorter reaction time and leads to less SrFe12O19 loss. The mass loss of SrFe12O19 during the FeCo coating process was investigated by washing as-synthesized SrFe12O19/FeCo particles with diluted acid. The results show that there is a negligible loss of SrFe12O19 during the FeCo coating process. This paper provides an easy way to precisely tailor the magnetic properties of magnetically exchange coupled SrFe12O19/FeCo core/shell particles. © 2015 Published by Elsevier B.V.

Lin C.X.C.,University of Queensland | Jambhrunkar S.,University of Queensland | Yuan P.,China University of PetroleumBeijing | Zhou C.H.C.,Zhejiang University of Technology | Zhao G.X.S.,University of Queensland
RSC Advances | Year: 2015

Recently many scientists are interested in replicating the unique structure and function of multi-compartments found in natural cells. Despite the success in recreating multi-compartment structures for organic materials, it is a great challenge to translate a similar concept into inorganic and hybrid materials for more versatile applications. Here, as the first example in the organosilica family, we present a facile synthesis route to create hybrid materials with a multi-compartment structure through the spontaneous assembly of fluorocarbon (FC) and hydrocarbon (HC) surfactants with the addition of co-solvent. The formation of multi-compartment periodic mesoporous organosilica (MCPMO) is triggered by the presence of organic co-solvent that induces an osmotic pressure difference in the system. The MCPMO demonstrates a high loading capacity of the antimalarial and anticancer drug artemisinin (47%) with a sustainable release profile attributed to the unique compartmentalized structure and hydrophobic properties. This synthesis strategy can be extended to design various materials with different compositions and morphologies for wider applications including microelectronics, biomedicine, catalysis and energy storage. © The Royal Society of Chemistry.

Zhu D.,China University of PetroleumBeijing | Sharma A.Z.,University of Manitoba | Wiebe C.R.,University of Winnipeg | Budzelaar P.H.M.,University of Manitoba
Dalton Transactions | Year: 2015

Oxidation of (MeBDI)Rh(cyclooctene) (MeBDI = [2,6-Me2C6H3NCMe]2CH) with Br2 or I2 produces paramagnetic halide-bridged RhII dimers [(MeBDI)Rh]2(μ-X)2 without a direct Rh-Rh bond. Steric factors are proposed to play a key role in preventing the formation of Rh-Rh bonded alternative structures. This journal is © The Royal Society of Chemistry.

Lv L.,Renmin University of China | Lu S.,Renmin University of China | Guo Q.,China University of PetroleumBeijing | Shen B.,China University of PetroleumBeijing | And 2 more authors.
Journal of Organic Chemistry | Year: 2015

Iron-catalyzed acylation-oxygenation of terminal alkenes is reported. Acyl radicals generated by the oxidation of aldehydes add to terminal alkenes and followed by intramolecular oxygenation give functionalized 2,3-dihydrofuran derivatives bearing a quaternary carbon. © 2014 American Chemical Society.

Song R.,China University of PetroleumBeijing | Feng X.,China University of Technology | Wang Y.,China University of PetroleumBeijing
Applied Thermal Engineering | Year: 2016

Interplant heat integration brings more opportunity to utilize the surplus/waste heat in individual plants. In most previous studies on interplant heat integration, either Grand Composite Curves (GCCs) or waste heat source/sink in the existing heat exchanger networks (HENs) were used for analysis. However, for these two methods, the former may generate intricate HENs, while the latter may miss some possible heat recovery potential. This paper investigates a way to achieve almost maximum possible heat recovery for indirect heat integration between two plants without basically changing the existing HENs. The selection of appropriate hot/cold streams participated in integration is investigated. A novel concept named Interplant Shifted Composite Curve (ISCC) is proposed to determine the maximum feasible heat recovery potential via indirect interplant heat integration and the minimum flowrate of a single-circuit intermediate medium used. Compared to the waste heat source/sink in the existing HENs being used directly for integration, a case study shows 43.1% of energy saving with minimum flowrate of a single-circuit intermediate medium, which can be easily obtained in the ISCC. Meanwhile, compared to the GCCs being used for integration, a scheme relatively easy and practical to implement can be achieved with the proposed method. © 2015 Elsevier Ltd.

Wang F.,China University of PetroleumBeijing | Pan Z.,China University of PetroleumBeijing | Zhang S.,China University of PetroleumBeijing
Applied Geochemistry | Year: 2016

Shale with high clay content has caused instability from hydration during the hydraulic fracturing process. Macro-level migration phenomenon of water molecules is induced by the chemical potential difference between low-salinity fracturing fluid and high-salinity formation brine. This study aims to establish the equation for the chemical potential difference between fracturing fluid and formation brine by theoretical deduction in order to investigate the effect of the aforementioned phenomenon on fracturing flowback. Accordingly, a mathematical model was established for the gas–water two-phase flow which driven by the chemical potential difference. Viscous force, capillarity and chemiosmosis were considered as the driving forces. A numerical simulation of fracturing fluid flowback with or without considering of the effect of chemiosmosis was performed. A simulation analysis of the water saturation and salinity profiles was also conducted. Results show that capillarity and chemiosmosis hinder fracturing fluid flowback in different degrees. As the condition worsens, they inhibit more than 80% of water to flow back out of the formation, forming a permanent water lock. This study contributes to improvement of the theory on shale gas–water two-phase flow, establishment of a flowback model that suitable for shale gas wells, and accurate evaluation of the fracturing treatment. © 2016 Elsevier Ltd

Yang L.,China University of PetroleumBeijing | Li M.,China University of PetroleumBeijing | Wang T.-G.,China University of PetroleumBeijing | Shi Y.,China National Petroleum Corporation
Journal of Petroleum Science and Engineering | Year: 2016

Dibenzothiophenes (DBTs) and benzo[b]naphthothiophenes (BNTs) are important sulfur heterocyclic aromatic compounds in oils and sedimentary rock extracts. Based on both migration fractionation effects and differences in thermal stability of different isomers, DBTs and BNTs can be used to trace oil migration orientations and filling pathways. They are present in significant abundances in oils, including light oils and condensates, in which biomarkers are commonly absent or present only in extremely low concentrations. Molecular biomarker compositions indicate that all oils and condensates in the Eocene clastic reservoir of the Fushan Depression (Beibuwan Basin, South China Sea) belong to a single oil population. In this study, three geochemical indicators relating to DBTs and BNTs, namely; (1), 4-/1-methyldibenzothiophene (4-/1-MDBT); (2), total content of DBTs; and (3), benzo[b]naphtha[2,1-d]thiophene/(benzo[b]naphtha[2,1-d]thiophene+benzo[b]naphtho[1,2-d]thiophene) ([1,2]BNT/([1,2]BNT+[1,2]BNT)) were applied to trace oil migration orientations and filling pathways. The results show that these parameter values gradually decrease from northeast to southwest, towards the Huachang Uplift, and from north to south towards the Bailian Faulted-Belts. Therefore, the source kitchen for identified oil accumulations in the Huachang Uplift is likely to be located in the Bailian Sag, which lies to the northeast of the Huachang Uplift. Zones in the Bailian Sag, situated upstream of the preferred oil filling pathways are likely to be the most favorable prospecting regions. It is concluded that relative parameters of DBTs and BNTs are practical molecular indicators for tracing oil migration orientations and filling pathways. © 2016 Elsevier B.V.

Duan L.,China University of PetroleumBeijing | Xie M.,China University of PetroleumBeijing | Bai T.,China University of PetroleumBeijing | Wang J.,China University of PetroleumBeijing
Expert Systems with Applications | Year: 2016

In machinery fault diagnosis area, the obtained data samples under faulty conditions are usually far less than those under normal condition, resulting in unbalanced dataset issue. The commonly used machine learning techniques including Neural Network, Support Vector Machine, and Fuzzy C-Means, etc. are subject to high misclassification with unbalanced datasets. On the other hand, Support Vector Data Description is suitable for unbalanced datasets, but it is limited for only two class classification. To address the aforementioned issues, Support Vector Data Description based machine learning model is formulated with Binary Tree for multi-classification problems (e.g. multi fault classification or fault severity recognition, etc.) in machinery fault diagnosis. The binary tree structure of multiple clusters is firstly drawn based on the order of cluster-to-cluster distances calculated by Mahalanobis distance. Support Vector Data Description model is then applied to Binary Tree structure from top to bottom for classification. The parameters of Support Vector Data Description are optimized by Particle Swarm Optimization algorithm taking the recognition accuracy as objective function. The effectiveness of presented method is validated in the rotor unbalance severity classification, and the presented method yields higher classification accuracy comparing with conventional models. © 2016 Elsevier Ltd

Shan S.,China University of PetroleumBeijing | Yuan P.,China University of PetroleumBeijing | Han W.,China University of PetroleumBeijing | Shi G.,China National Petroleum Corporation | Bao X.,China National Petroleum Corporation
Journal of Catalysis | Year: 2015

Abstract This article reports a novel method for preparing supported NiW hydrodesulfurization (HDS) catalysts with tunable size and morphology of active phases to achieve highly selective HDS performance in hydro-upgrading fluid catalytic cracking (FCC) naphtha. The proposed approach features the combined use of W-based hybrid nanocrystals (HNCs) as the W precursor and the promoting effect optimization of Ni promoter. The W-based HNCs synthesized under mild hydrothermal conditions are monodispersed particles with an average size of ca. 2 nm and show a core-shell structure with W6O192- as the inorganic core and short-chain quaternary ammonium cations as the organic shell. The use of W-based HNCs facilitates the formation of highly dispersed W species and WS2 active phases with enhanced stacking, thus yielding a larger number of accessible Ni-W-S edge sites upon nickel impregnation. Moreover, we found that the advantageous W dispersion in the HNC-derived monometallic catalyst precursor allows further modification of the size and morphology of the active phase via the optimized incorporation of Ni promoter, leading to the formation of Ni-W-S edge sites with a lower percentage of brim sites and thereby resulting in considerably higher selective HDS performance for FCC naphtha than its counterpart prepared by the conventional impregnation method. The proposed approach makes it easy to tune the size and morphology of WS2 nanoparticles, shedding light on the rational design of supported WS2 catalysts for FCC naphtha selective HDS. © 2015 Elsevier Inc.

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