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Enhancement of Hydrogen Sorption on Metal（Ni, Rh, Pd） Functionalized Carbon Nanotubes： a DFT Study

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Chemical Research in Chinese Universities 2017年第3期33卷 422-429页

作者： XIAO Lu chu wei SUN Wenjing XUE Ying JIANG Chengfa School of Chemical Engineering Sichuan University Chengdu 610065 P. R. China China-America Cancer Research Institute Key Laboratory for Medical Molecular Diagnostics of Guangdong Province Guangdong Medical University Dongguan 523808 P. R. China

Hydrogen interacted with pristine single-walled carbon nanotubes（SWNTs） and single/dimer metal doped ones（M-CNTs） was investigated via density functional theory（DFT） simulations. The most stable configurations of Ni, Rh, Pd on SWNTs were identified. The interaction of H2 molecules with pristine SWNTs and M-CNTs was investigated. The results show that H2 molecules can be adsorbed on the pristine SWNTs via a weak physical interaction, which is much weaker than those of H2 molecules with M-CNTs by chemisorption. Each Ni, Rh and Pd doped SWNTs can respectively chemisorb three, two, or one H2 molecules and the H-H bond of H2 molecule is elongated. Furthermore, the H2 molecule could be dissociated owing to the presence of the Ni-Ni bond for Ni dimer doped SWNT, forming new Ni-H bonds. While such a dissociation could not be observed on RhJPd2-CNT samples. Density of state（DOS） results show that the s orbital of hydrogen can hybridize with the d orbital of metal atom, re- sulting in the stronger inteaction between H2 and M-CNTs, impying that the hydrogen storage capacity could be en- hanced in the presence of M-CNTs. The comparison of the interaction mechanism among different metals doped CNTs can screen out the most effective hydrogen-adsorption materials and the design of the related materials by computational approaches.

关键词： Hydrogen sorption Carbon nanotube Metal doped Density functional theory

Low-temperature CO oxidation over CuO-CeO_2/SiO_2 catalysts:Effect of CeO_2 content and carrier porosity

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Journal of Natural Gas Chemistry 2010年第4期19卷 355-361页

作者： Jingjie Luo wei chu Huiyuan Xu Chengfa Jiang Tao Zhang Department of Chemical Engineering Sichuan University Chengdu 610065 Sichuan China Dalian Institute of Chemical Physics Chinese Academy of Sciences Dalian 116023 Liaoning China

The effects of CeO2 contents and silica carrier porosity with their pore diameters ranging from 5.2 nm to 12.5 nm of CuO-CeO2/SiO2 cata-lysts in CO oxidation were *** catalysts were characterized by N2 adsorption/desorption at low temperature,X-ray diffraction （XRD）,temperature-programmed reduction by H2 （H2-TPR）,oxygen temperature programmed desorption （O2-TPD） and X-ray photoelectron spectroscopy （XPS）.The results suggested that,the ceria content and the porosity of SiO2 carrier possessed great impacts on the structures and catalytic performances of CuO-CeO2/SiO2 *** appropriate content of CeO2 （Ce content 8 wt%） was added,the catalytic activity was greatly *** the catalyst supported on silica carrier with larger pore diameter,higher dispersion of CuO was observed,better agglomeration-resistant capacity was displayed and more lattice oxygen could be found,thus the CuO-CeO2 supported on Si-1 showed higher catalytic activity for low-temperature CO oxidation.

关键词： CuO-CeO2 based catalyst silica carrier porosity carbon monoxide oxidation O2-TPD

Protecting User Privacy in a Multi-Path Information-Centric Network Using Multiple Random-Caches

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Journal of Computer Science & Technology 2017年第3期32卷 585-598页

作者： wei-Bo chu Li-Fang Wang Ze-Jun Jiang Chin-Chen Chang School of Computer Science and Technology Northwestern Polytechnical University Xi'an 710072 China Department of Information Engineering and Computer Science Feng Chia University Taichung Taiwan 40724 China

In-network caching is a fundamental mechanism advocated by information-centric networks （ICNs） for efficient content delivery. However, this new mechanism also brings serious privacy risks due to cache snooping attacks. One effective solution to this problem is random-cache, where the cache in a router randomly mimics a cache hit or a cache miss for each content request/probe. In this paper, we investigate the effectiveness of using multiple random-caches to protect cache privacy in a multi-path ICN. We propose models for characterizing the privacy of multi-path ICNs with random-caches, and analyze two different attack scenarios： 1） prefix-based attacks and 2） suffix-based attacks. Both homogeneous and heterogeneous caches are considered. Our analysis shows that in a multi-path ICN an adversary can potentially gain more privacy information by adopting prefix-based attacks. Furthermore, heterogeneous caches provide much better privacy protection than homogeneous ones under both attacks. The effect of different parameters on the privacy of multi-path random-caches is further investigated, and the comparison with its single-path counterpart is carried out based on numerical evaluations. The analysis and results in this paper provide insights in designing and evaluating multi-path ICNs when we take privacy into consideration.

关键词： information-centric network (ICN) user privacy cache snooping random-cache multi-path

Size-controlled flow synthesis of metal-organic frameworks crystals monitored by in-situ ultraviolet-visible absorption spectroscopy

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Chinese Chemical Letters 2021年第3期32卷 1131-1134页

作者： Wenbo Li Yucen Li wei Zhang Difeng Yin Ya Cheng wei chu Ming Hu State Key Laboratory of High Field Laser Physics and CAS Center for Excellence in Ultra-Intense Laser Science Shanghai Institute of Optics and Fine Mechanics(SIOM)Chinese Academy of Sciences(CAS)Shanghai 201800China School of Physical Science and Technology ShanghaiTech UniversityShanghai 200031China State Key Laboratory of Precision Spectroscopy School of Physics and Electronic ScienceEast China Normal UniversityShanghai 200241China XXL-The Extreme Optoelectromechanics Laboratory School of Physics and Electronic ScienceEast China Normal UniversityShanghai 200241China University of Chinese Academy of Sciences Beijing 100049China

Size-controlled flow synthesis of nanoporous particles are of considerable interest for future industrial applications,however,is facing challenges due to lack of in-situ method for size-characterization in fluidic *** present that ultraviolet-visible(UV-vis)absorption spectroscopy can be integrated into a flow-synthesis system which was produced by femtosecond laser micro *** shift of the absorption peak position of the ex-situ and in-situ UV-vis spectra correlates to variation of size of porous metal-organic frameworks ***-67 crystals with a size in the range from 200 nm to1025 nm are fabricated with the assistance of tri-ethylamine under monitoring of in-situ UV-vis *** ZIF-67 crystals are converted into nanoporous carbons particles with controlled *** materials show size-dependent performance in Na-ion battery and size-independent performance in metal/H_(2)O seawater battery.

关键词： Nanoporous particles Microfluidics Flow synthesis Metal-organic frameworks UV-vis absorption spectrum Femtosecond laser micromachining

Signature of symmetry of laterally coupled quantum dots in far-infrared spectrum

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Chinese Physics B 2012年第2期21卷 477-482页

作者： Gu Li-Ying Li Yan-Fang chu wei-Dong wei Ying-Hui College of Materials Science and Engineering Taiyuan University of TechnologyTaiyuan 030024China Institute of Applied Physics and Computational Mathematics Beijing 100088China

We study the effect of structure asymmetry on the energy spectrum and the far-infrared spectrum （FIR） of a lateral coupled quantum dot. The calculated spectrum shows that the parity break of coupled quantum dot results in more coherent superpositions in the low-lying states and exhibits unique anti-crossing in the two-electron FIR spectrum modulated by a magnetic field. We also find that the Coulomb correlation effect can make the FIR spectrum of coupled quantum dot without strict parity deviate greatly from Kohn theorem, which is just contrary to the symmetric case. Our results therefore suggest that FIR spectrum may be used to determine the symmetry of coupled quantum dot and to evaluate the degree of Coulomb interaction.

关键词： structure symmetry far-infrared spectrum coupled quantum dot Coulomb interaction

Fractal dimension of coal particles and their CH_4 adsorption

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International Journal of Mining Science and Technology 2012年第6期22卷 845-848页

作者： Wang Chengyang Hao Shixiong Sun Wenjing chu wei Department of Chemical Engineering Sichuan University Department of Chemical Engineering Sichuan University of Science & Engineering

We describe the fractal analysis of three differently sized coal samples(0.350-0.833 mm,0.245-0.350 mm,and 0.198-0.245 mm).The influence of fractal dimension on CH 4 adsorption capacity is *** physical parameters of the samples were determined via the Brunauer-Emmett-Teller(BET) theory.A CH 4 adsorption study over the pressures range from 0 to 5 MPa was carried out with a new volumetric measurement *** CH 4 adsorption was measured using the differently sized *** fractal dimensions,D 1 and D 2 were determined over the pressure ranges from 0 to 0.5 MPa and from 0.5 to 1 MPa,using the Frenkel-Halsey-Hill(FHH) *** conclude that the two fractal dimensions correlate with the CH 4 adsorption capacity of the coal:increasing CH 4 adsorption capacity occurs with a corresponding increase in fractal ***,D 1 and D 2 are positively correlated with surface area,pore volume,and samples *** size distribution of the samples has fractal characteristics.

关键词： Coal Fractal dimension Frenkel-Halsey-Hill Brunauer-Emmett-Teller Adsorption isotherm

Immobilization of 12-phosphotungstic heteropolyacid onamine-functionalized SiO_2 for tetrahydrofuran polymerization

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Chinese Science Bulletin 2010年第24期55卷 2652-2656页

作者： HUANG Ming chu wei LIAO XueMei DAI XiaoYan Department of Chemical Engineering Sichuan University Chengdu 610065 China

The 12-phosphotungstic heteropolyacid(HPW)was immobilized on the surface of a silica carrier modified by the amine groups of organosilaneγ-aminopropyl triethoxysilane(APTES),and its catalytic performance was investigated for tetrahydrofuran(THF) ring-opening *** amine-functionalized catalyst exhibited better activity,and the polytetramethylene ether glycol (PTMG)yield was 63.7%.The 12-phosphotungstic heteropolyacid supported on aminopropyl-functionalized SiO2 support (HPW/SiO2-APTES)was reused four times and showed a good maintenance of activity which was better than that of the conventional catalyst HPW supported on SiO2(HPW/SiO2).These results were obtained using infrared spectroscopy,nuclear magnetic resonance spectroscopy,nitrogen adsorption and X-ray *** on the HPW/SiO2-APTES catalyst exhibited higher dispersed state and maintained a more stable structure than that of the HPW/SiO2 sample.

关键词：磷钨杂多酸四氢呋喃开环聚合功能化二氧化硅磷钨酸催化剂固定化核磁共振光谱

Oxidative dehydrogenation of ethane with carbon dioxide over silica molecular sieves supported chromium oxides:Pore size effect

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Chinese Journal of Chemical Engineering 2021年第6期34卷 77-86页

作者： Zhibin Deng Xing Ge Wenting Zhang Shizhong Luo Jun Shen Fangli Jing wei chu College of Civil Aviation Safety Engineering Civil Aviation Flight University of ChinaGuanghan 618307China Sinopec Petroleum Exploration and Production Research Institute Northwest Oilfield BranchUrumqi 830011China School of Chemical Engineering Sichuan UniversityChengdu 610065China

SBA-15 with varied pore size from 4 to 8 nm were synthesized by tuning the temperature of hydrothermal treatment,the supports were then used to load the active phase Cr Oxthrough a conventional impregnation *** resulting catalysts were characterized by small/wide angle XRD,N_(2) adsorption/desorption,FT-IR,TEM-EDX,XPS,TPR and CO_(2)-TPD to study the feature of structure,surface chemical state,redox and *** was found from these results that the metal species could be well dispersed on catalysts with larger pore ***^(6+)species could enter into the framework by substituting the Si atoms of SBA-15,and Cr^(3+)mainly exist on extra *** size had profound effects on reducibility,surface composition and ***^(6+)species were necessary to activate the C-H bonds of alkanes,while the basicity played an important role in activating C-O bonds of CO_(2).The best performances were achieved over the sample Cr supported on SBA-15 with a pore diameter of 7 nm in oxidative dehydrogenation of ethane in the presence of CO_(2).

关键词： Ethylene SBA-15 Pore size effect Cr catalysts Heterogeneous catalysis

Empirical Analysis of Provincial Energy Efficiency in China

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China & World Economy 2009年第5期17卷 88-103页

作者： chu wei Jinlan Ni Manhong Shen College of Economics and Management Zhejiang Sci-Tech University Zhejiang China Department of Economics University of Nebraska Omaha USA

This paper proposes an energy efficiency index based on the data envelopment analysis approach. The index is used to examine energy efficiency in China. Using 1997-2006panel data for 29 provinces, we find that energy efficiency is negatively associated with the secondary industry share in GDP, the state-owned economic share in GDP and the government expenditure share in GDP, and is positively associated with the technical level and non-coal share in energy consumption. In addition, we find that there exists a large gap in energy efficiency among eastern, central and western regions. The eastern region has a significantly higher energy efficiency level than the eentral and western regions. We conclude that the different levels of industry structure, government intervention, energy structure, and the technology content in the three regions lead to the differences in energy efficiency.

关键词： China data envelopment analysis determinants energy efficiency