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Hydrodesulfurization catalyst prepared by urea-matrix combustion method

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Particuology 2012年第4期10卷 468-474页

作者： Dongmei Jiao YeyongMa Fahai Cao School of Chemical Engineering East China University of Science and Technology130 Meilong RoadShanghaiChina Luoyang Petrochemical Complex of SINOPEC 1 Zhongyuan RoadLuoyangChina Petro-Cyber Works Information Technology Co. Ltd.192 Eshan RoadShanshaiChina

Co-Mo/γ-Al2O3-TiO2 hydrodesulfurization （HDS） catalyst samples prepared by a urea matrix combustion （UMxC） method, were evaluated in a stainless tubular fixed-bed reactor, with thiophene, benzothiophene and dibenzothiophene in xylene as model feedstocks. The samples were pre-sulfurized using a cyclohex- ane solution of 3% CS2 and then tested for the HDS reaction. The test results were compared with catalysts prepared by conventional methods involving sequential impregnation （SI） and co-impregnation （CI）. The catalysts were characterized using X-ray diffraction （XRD）, laser Raman spectroscopy （LRS）, high resolu- tion transmission electron microscopy （HRTEM） and N2 physisorption, showing that the UMxC catalyst had higher pore volume and surface area than those prepared by the CI and SI methods. The UMxC method increased metal loading and avoided formation of inert phase, e.g., β-CoMoO4, for the HDS reaction, sug- gesting that UMxC method is superior to the conventional impregnation techniques. TiO2 promoter made particles on the catalyst surface closer and alleviated the interaction between molybdenum oxide and the support, and facilitated the formation of well-dispersed Co- and Mo-oxo species on catalyst surface, thus resulting in higher HDS catalytic activity than pure γ-Al2O3 support without modifiers. Consequently, the addition of TiO2 obviously improved the HDS conversion of dibenzothiophene.

关键词： HydrodesulfurizationCo-Mo catalystAl2O3-TiO2 supportUrea-matrix combustion methodPreparation

Stochastic averaging method for estimating first-passage statistics of stochastically excited Duffing-Rayleigh-Mathieu system

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Acta Mechanica Sinica 2008年第5期24卷 575-582页

作者： Yongjun Wu Wang Fang Institute of Automation School of Information Scienceand Engineering East China University of Science and TechnologyShanghai 200237 China Hangzhou Yiheng Technologies Co. Ltd 2F28 Wantang Road Hangzhou 310013 China

The first-passage statistics of Duffing-Rayleigh- Mathieu system under wide-band colored noise excitations is studied by using stochastic averaging method. The motion equation of the original system is transformed into two time homogeneous diffusion Markovian processes of amplitude and phase after stochastic averaging. The diffusion process method for first-passage problem is used and the corresponding backward Kolmogorov equation and Pontryagin equation are constructed and solved to yield the conditional reliability function and mean first-passage time with suitable initial and boundary conditions. The analytical results are confirmed by Monte Carlo simulation.

关键词： First-passage Colored noise Stochastic averaging Reliability Monte Carlo simulation

Feedforward Variable Structural Proportional-Integral-Derivative for Temperature Control of Polymerase Chain Reaction

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Chinese Journal of Chemical Engineering 2006年第2期14卷 200-206页

作者：邱宪波袁景淇汪志锋 Department of Automation Shanghai Jiao Tong University Shanghai 200030 China State Key Laboratory of Bioreactor Engineering East China University of Science and Technology Shanghai 200237 China Department of Automation Shanghai Second Polytech University Shanghai 201209 China

To track the rapidly changing temperature profiles of thermal cycling of polymerase chain reaction （PCR） accurately, an innovative feedforward variable structural proportional-integral-derivative （FVSPID） controller was developed. Based on the step response test data of the heat block, a reduced first order model was estabfished at different operating points. Based on the reduced model, the FVSPID controller combined a feedforward path with the variable structural proportional-integral-derivative （PID） control. The modified feedforward action provided directly the optimal predictive power for the desired setpoint to speed up the dynamic response. To cooperate with the feedforward action, a variable structural PID was applied, where the P mode was used in the case of the largest errors to speed up response, whereas the PD mode was used in the case of larger errors to suppress overshoot, and finally the PID mode was applied for small error conditions to eliminate the steady state offset. Experimental results illustrated that compared to the conventional PID controller, the FVSPID controller can not only reduce the time taken to complete a standard PCR protocol, but also improve the accuracy of gene amplification.

关键词： feedforward variable structural PID controller polymerase chain reaction thermal cycling temperature tracking

Modeling online social networks based on preferential linking

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Chinese Physics B 2012年第11期21卷 573-578页

作者：胡海波郭进利陈骏 Department of Management East China University of Science and Technology School of Management University of Shanghai for Science and Technology

We study the phenomena of preferential linking in a large-scale evolving online social network and find that the linear preference holds for preferential creation, preferential acceptance, and preferential attachment. Based on the linear preference, we propose an analyzable model, which illustrates the mechanism of network growth and reproduces the process of network evolution. Our simulations demonstrate that the degree distribution of the network produced by the model is in good agreement with that of the real network. This work provides a possible bridge between the micro=mechanisms of network growth and the macrostructures of online social networks.

关键词： online social network preferential linking model power law

Logically Sensing Aggregate Process and Discriminating SDS from Other Surfactants with the Assistance of BSA

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Chinese Journal of Chemistry 2012年第6期30卷 1283-1288页

作者：钱俊红徐玉芳钱旭红 School of Chemistry and Molecular Engineering East China University of Science and TechnologyShanghai 200237China Shanghai Key Laboratory of Chemical Biology School of PharmacyEast China University of Science and TechnologyShanghai 200237China

An amphiphilic fluorescent probe, 3-dodecylamino dihydrogen imidazo[2,l-a]benz[de]isoquinolin-7-one （compound 3）, was used to sense the aggregate formation process of bovine serum albumine （BSA）, sodium dode- cyl sulfate （SDS） and their mixed system. The fluorescence intensity of 3 was significantly affected by the adding order of SDS and BSA, and SDS can be distinguished from other surfactants with the aid of BSA, but only when 3 is allowed to interact with BSA first. The results revealed that compound 3 is preferentially sited in the hydrophobic region of BSA, and thermodynamically in SDS-BSA mixed aggregate. Sodium phosphate buffer solution （PBS） and BSA played important but distinct roles in distinguishing SDS micelle from the others.

关键词： fluorescent sensor micelle sodium dodecyl sulfate (SDS) bovine serum albumine (BSA) adding or-der

Preparation and characterization of m PEG grafted chitosan micelles as 5-fluorouracil carriers for effective anti-tumor activity

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Chinese Chemical Letters 2014年第11期25卷 1435-1440页

作者： Dong-Jun Fu Yu Jin Mu-Qing Xie Ya-Jing Ye Dong-Dong Qin Kai-Yan Lou Yan-Zuo Chen Feng Gao Department of Pharmaceutics School of Pharmacy East China University of Science and Technology Shanghai Key Laboratory of Functional Materials Chemistry East China University of Science and Technology Shanghai Key Laboratory of New Drug Design East China University of Science and Technology

The objective of this study was to investigate the potential of methoxy polyethylene glycol（m PEG）grafted chitosan（m PEG-g-CS） to be used as a drug carrier. m PEG-g-CS was successfully synthesized by one-step method with formaldehyde. The substitution degree of m PEG on chitosan was calculated by elemental analysis and was found to be（3.23 0.25）%. m PEG-g-CS self-assembled micelles were prepared by ultrasonic method with the controlled size of 178.5–195.1 nm and spherical morphology. Stable dispersion of the micelles was formed with the zeta potential of 2.3–30.2 m V. 5-Fluorouracil（5-FU）, an anticancer chemotherapy drug, was used as a model drug to evaluate the efficiency of the new drug delivery carrier. The loading efficiency of 5-FU was（4.01 0.03）%, and the drug-loaded m PEG-g-CS self-assembled micelle showed a controlled-release effect. In summary, the m PEG-g-CS self-assembled micelle is proved to be a promising carrier with controlled particle size and controlled-release effect. Therefore, it has great potential for the application as 5-FU carriers for effective anti-tumor activity.

关键词： Self-assembled micelles Methoxy polyethylene glycol grafted chitosan 5-Fluorouracil Controlled-release

Highly efficient Nb2O5 catalyst for aldol condensation of biomass-derived carbonyl molecules to fuel precursors

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Chinese Journal of Catalysis 2019年第8期40卷 1168-1177页

作者： Yaxuan Jing Yu Xin Yong Guo Xiaohui Liu Yanqin Wang Shanghai Key Laboratory of Functional Materials Chemistry Research Institute of Industrial CatalysisSchool of Chemistry and Molecular EngineeringEast China University of Science and TechnologyShanghai 200237China

Aldol condensation is of significant importance for the production of fuel precursors from biomass- derived chemicals and has received increasing attention. Here we report a Nb2O5 catalyst with excellent activity and stability in the aldol condensation of biomass-derived carbonyl molecules. It is found that in the aldol condensation of furfural with 4-heptanone, Nb2O5 has obviously superior activity, which is not only better than that of other common solid acid catalysts (ZrO2 and Al2O3), more importantly, but also better than that of solid base catalysts (MgO, CaO, and magnesium- aluminum hydrotalcite). The detailed characterizations by N2 sorption/desorption, NH3-TPD, Py-FTIR and DRIFTS study of acetone adsorption reveal that Nb2O5 has a strong ability to activate the C=O bond in carbonyl molecules, which helps to generate a metal enolate intermediate and undergo the nucleophilic addition to form a new C–C bond. Furthermore, the applicability of Nb2O5 to aldol condensation is extended to other biomass-derived carbonyl molecules and high yields of target fuel precursors are obtained. Finally, a multifunctional Pd/Nb2O5 catalyst is prepared and successfully used in the one-pot synthesis of liquid alkanes from biomass-derived carbonyl molecules by combining the aldol condensation with the sequential hydrodeoxygenation.

关键词： Aldol condensation Nb2O5 C=O activation Fuel precursor Bio-liquid alkane One-pot process

Translocation of Polymer Through a Nanopore Studied by Langevin Dynamics:Effect of the Friction Coefficient

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Chinese Journal of Chemical Engineering 2012年第2期20卷 231-238页

作者：冯剑尚亚卓周丽绘刘洪来胡英 Department of Applied Chemistry Chuzhou University State Key Laboratory of Chemical Engineering and Department of Chemistry East China University of Science and Technology

The driven polymer translocation through a nanopore with unbiased initial configuration has been studied by using Langevin dynamics(LD) *** is found that the scaling relationship between translocation time and the polymer chain length is strongly affected by the friction coefficient in LD and the driving ***,there is no scaling relationship between the translocation time and the friction *** translocation time is almost inversely proportional to the driving force,which is in agreement with those obtained in biased *** scaling relationship between gyration radius(R g) of subchain at the trans side with the subchain length(L) is R g ～L 0.33 that is in good agreement with the limiting value for molten globule state,while the curve of R g of subchain at the cis side has two distinct *** translocation,the subchain at the cis side is being stretched gradually,and the structure of the subchain transforms from sphere-like to *** the effect of stretching reaches the tail end,the subchain is at the most stretched *** the subchain will rapidly restore to coil *** to the results of force analysis,the retarding force at the trans side is more crucial during the practical translocation.

关键词： translocation Langevin dynamics friction coefficient polymer nanopore

Predictive model-aided filtering scheme of data-collection in WSN

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The Journal of China Universities of Posts and Telecommunications 2011年第2期18卷 17-24页

作者： HUANG RU ZHANG Zai-chen XU Guang-hui School of Information Science and Engineering East China University of Science and Technology Shanghai 200237 China State Key Laboratory of Mobile Communications Southeast University Nanjing 210096 China Institute of Communications Engineering PLA University of Science and Technology Nanjing 210007 China

The paper proposes a prediction-mode-based filtering mechanism（PMF） to solve the problems of transmission energy wasting caused by time-redundant data in wireless sensor networks（WSN）,according to the characteristic of spatio-temporal correlations on sampling series in *** works have suggested several approaches to decrease energy cost during data transmission process via data aggregation tree *** from those methods in above researches,our proposed scheme mainly focus on reducing the temporal redundant degree in event-source to achieve energy-saving effect via self-adaptive filtering *** framework of PMF for energy-efficient collection is composed of prediction module for mining the change law of time domain,self-learning module for updating model,and driving module for controlling data filtering *** with the design of error driving rule and threshold distributing rule,which is the middleware in the above filtering mechanism,the quantity of transmission load in networks can be greatly inhibited on the premise of quality of service（QoS） assurance and energy consumption can be reduced ***,the experimental results show that the performance of PMF can significantly outperform some classical data-collection algorithms on energy-saving effect and self-adaptability.

关键词： WSN data-collection filtering mechanism energy-saving