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Effects of postthermal treatment and UV irradiation on the structure of titania-polyacrylate nanocomposites

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Journal of University of Science and Technology Beijing 2006年第4期13卷 372-379页

作者： Tao Wan fei feng Yuechuan Wang State Key Laboratory of Polymer Materials Engineering College of Polymer Science and Engineering Sichuan University Chengdu 610065 China College of Materials and Chemistry ＆ Chemical Engineering Chengdu University of Technology Chengdu 610059 China

The effects of postthermal treatment and irradiation time on the structure and thermal stability of TiO2/polyacrylate nanocomposites by a sol-gel process in reverse micelles and subsequent rapid photopolymerization were investigated, and the hybrid films were characterized by thermal gravimetry analysis （TGA）, X-ray photoelectron spectrum （XPS）, and atomic force microscopy （AFM）. XPS data suggested that the prolongation of irradiation time and the postthermal treatment promoted titania formation, with the former affecting more remarkably. TGA data showed that TiO2-hybrid films could upgrade the decomposition onset temperature （Tonset） as well as the temperature at which there is a maximum mass loss rate （Tmax）. AFM data demonstrated that the inorganic titania particles with a mean diameter of 25.26-28.84 nm were homogeneously distributed in the organic matrix.

关键词： titanium dioxide reverse micelles sol-gel method photopolymerization nanocomposites

Design Schemes and Comparison Research of the End-effector of Large Space Manipulator

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Chinese Journal of Mechanical Engineering 2012年第4期25卷 674-687页

作者： feng fei LIU Yiwei LIU Hong CAI Hegao State Key Laboratory of Robotics and System Harbin Institute of Technology Harbin 150080 China

The end-effector of the large space manipulator is employed to assist the manipulator in handling and manipulating large payloads on ***,there are few researches about the end-effector,and the existing end-effectors have some disadvantages,such as poor misalignment tolerance capability and complex mechanical *** to the end positioning errors and the residual vibration characters of the large space manipulators,two basic performance requirements of the end-effector which include the capabilities of misalignment tolerance and soft capture are *** the end-effector should accommodate the following misalignments of the mechanical *** translation misalignments in axial and radial directions and the angular misalignments in roll,pitch and yaw are ±100 mm,100 mm,±10°,±15°,±15°,*** end-effector schemes are presented and the capabilities of misalignment tolerance and soft capture are analyzed *** three fingers-three petals end-effector and the steel cable-snared end-effector are the most feasible schemes among the seven schemes,and they are designed in *** capabilities of misalignment tolerance and soft capture are validated and evaluated,through the experiment on the micro-gravity simulating device and the dynamic analysis in ADAMS *** results show that the misalignment tolerance capabilities of these two schemes could satisfy the *** the translation misalignment tolerances in axial and radial directions and the angular misalignment tolerances in roll,pitch and yaw of the steel cable-snared end-effector are 30mm,15mm,6°,3° and 3° larger than those of the three fingers-three petals end-effector,*** the contact force of the steel cable-snared end-effector is smaller and smoother than that of the three fingers-three petals *** end-effector schemes and research methods are beneficial to the developments of the large space manipulator end-effctor and t

关键词： end-effector large space manipulator docking mechanism soft capture misalignment tolerance passive compliance active compliance

Technical assessment of synthetic natural gas (SNG) production from agriculture residuals

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Journal of Thermal Science 2013年第4期22卷 359-365页

作者： Guohui Song fei feng Jun Xiao Laihong Shen Key Laboratory of Energy Thermal Conversion and Control of Ministry of Education School of Energy and Environment Southeast University Department of Mechanical Technology Nanjing College of Chemical Technology

This paper presents thermodynamic evaluations of the agriculture residual-to-SNG process by thermochemical conversion, which mainly consists of the interconnected fluidized beds, hot gas cleaning, fluidized bed methanation reactor and Selexol absorption unit. The process was modeled using Aspen Plus soft-ware. The process performances, i.e., CH4 content in SNG~ higher heating value and yield of SNGexergy efficiencies with and without heat recovery, unit power consumption, were evaluated firstly. The results indicate that when the other parameters remain unchanged, the steam-to-biomass ratio at carbon boundary point is the optimal value for the process. Im proving the preheating temperatures of air and gasifying agent is beneficial for the SNG yield and exergy effi ciencies. Due to the effects of COz removal efficiency, there are two optimization objectives for the SNG produc tion process：（I） to maximize CH4 content in SNC or （II） to maximize SNG yield. Further, the comparison among different feedstocks indicates that the decreasing order of SNG yield is： corn stalk 〉 wheat straw 〉 rice straw. The evaluation on the potential of agriculture-based SNG shows that the potential annual production of agriculture re sidual-based SNG could be between 555 108 - 611 108 m3 with utilization of 100% of the available unexplored resources. The agriculture residual-based SNG could play a significant role on solving the big shortfall of China＇s natural gas supply in future.

关键词： synthetic natural gas agriculture residual biomass gasification methanation fluidized bed exergy

Effect of cooling rate during quenching on the microstructure and creep property of nickel-based superalloy FGH96

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International Journal of Minerals,Metallurgy and Materials 2019年第4期26卷 493-499页

作者： Ye-fei feng Xiao-ming Zhou Jin-wen Zou Gao-feng Tian Science and Technology on Advanced High Temperature Structural Materials Laboratory Beijing Institute of Aeronautical Materials

The effect of cooling rate during quenching on the microstructure and creep property of nickel-based superalloy FGH96 was investigated. Three groups of samples were quenched continuously with three fixed cooling rates, respectively, then subjected to a creep test under a constant load of 690 MPa at 700℃. Clear differences in size of secondary γ′ precipitates, creep properties and substructure of creep-tested samples were observed. The quantitative relationship among cooling rate, the size of secondary γ′ precipitates, and steady creep rate was constructed. It was found that with increasing cooling rate, the size of secondary γ′ precipitates decreases gradually, showing that the relationship between the size of secondary γ′ precipitates and the cooling rate obeys a power law, with an exponent of about –0.6, and the creep rate of steady state follows a good parabola relationship with cooling γ′ precipitate size. For 235℃/min, FGH96 alloy exhibited very small steady creep rate. The density of dislocation was low, and the isolated stacking fault was the dominant deformation mechanism. With decreasing cooling rates, the density of dislocation increased remarkably, and deformation microtwinning was the dominant deformation process. Detailed mechanisms for different cooling rate were discussed.

关键词： quantitative relationship cooling rate secondaryγ′precipitates steady creep rate deformation mechanism

Inhibitory effects of polyphyllins I and VII on human cisplatin-resistant NSCLC via p53 upregulation and CIP2A/AKT/mTOR signaling axis inhibition

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Chinese Journal of Natural Medicines 2019年第10期17卷 768-777页

作者： feng fei-fei CHENG Peng SUN Chao WANG Hui WANG Wei Department of Respiratory Medicine The Second Hospital of Shandong UniversityJinan 250033China Department of Neural Medicine The Second Hospital of Shandong UniversityJinan 250033China Department of Central Laboratory The Second Hospital of Shandong UniversityJinan 250033China

Cancerous inhibitor of protein phosphatase 2A(CIP2A) is a human oncoprotein that is overexpressed in multiple kinds of cancers including non-small cell lung cancer(NSCLC). CIP2A plays an ’oncogenic nexus’ to participate in the tumorigenesis and chemoresistance in several cancer types. AKT and m TORC1 overactivation are detected in NSCLC and many other cancers. Previous studies found that the CIP2A/AKT/m TOR pathway controls cell growth, apoptosis, autophagy process. Polyphyllin I(PPI) and polyphyllin VII(PPVII) are natural components extracted from Paris polyphylla that display anti-cancer properties. In the present study, we investigated whether PPI and PPVII can be used in the cisplatin(DDP)-resistant human NSCLC cell line A549/DDP. Results demonstrated that PPI and PPVII treatment significantly suppressed A549/DDP cell proliferation, migration, invasion and EMT, induced apoptosis and autophagy. Further examination of the mechanism revealed that the PPI and PPVII significantly upregulated the p53, induced caspase-dependent apoptosis and suppressed the CIP2A/AKT/m TOR pathway. The activation of autophagy was mediated through PPI and PPVII induced inhibition of m TOR. We propose that PPI and PPVII might be developed as candidate drugs for DDP-resistant NSCLC.

关键词： Polyphyllin I Polyphyllin VII Cisplatin-resistance Non-small cell lung cancer p53 Cancerous inhibitor of protein phosphatase 2A

Simultaneous realization of direct photodeposition and high H_(2)-production activity of amorphous cobalt sulfide nanodot-modified rGO/TiO_(2)photocatalyst

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Rare Metals 2021年第11期40卷 3125-3134页

作者： feng Chen Hong-fei feng Wei Luo Ping Wang Huo-Gen Yu Jia-Jie Fan School of Chemistry Chemical Engineering and Life SciencesWuhan University of TechnologyWuhan 430070China State Key Laboratory of Silicate Materials for Architectures Wuhan University of TechnologyWuhan 430070China School of Materials Science and Engineering Zhengzhou UniversityZhengzhou 450002China

To realize highly efficient hydrogen production of graphene-based photocatalysts,it is greatly important to increase more interfacial active sites onto *** this work,the highly efficient CoS_(x)-rGO(reduced graphene oxide)/TiO_(2) composite photocatalyst was synthesized via a simple two-step method,including the hydrothermal loading of rGO nanosheets onto TiO_(2) nanoparticles and the subsequent photodeposition process of CoS_(x) nanodots(0.5-2 nm) on the rGO *** experimental results confirmed that the CoS_(x)-rGO/TiO_(2) photocatalyst displayed a distinctly higher photocatalytic H_(2)-evolution activity than the TiO_(2) *** highest hydrogen-production efficiency of obtained CoS_(x)-rGO/TiO_(2)(10%) achieved 256.97 μmol·h-1,which was distinctly higher than that of TiO_(2)(4.41 μmol·h-1),rGO/TiO_(2)(20.19 μmol·h^(-1)) and CoS_(x)/TiO_(2)(132.67 μmol·h^(-1)).According to the results of various characterizations and tests,the synergistic-effect mechanism of CoS_(x) nanodots and rGO nanosheets is proposed to explain the increased photocatalytic performance of Co S_(x)-rGO/TiO_(2) photocatalytic material,namely the rGO nanosheets cause the quick transfer of photo-induced carriers from TiO_(2) to CoS_(x) nanodots,and then CoS_(x) nanodots work as hydrogenproduction active sites to quickly generate H_(2).The present study may offer innovative ideas for the preparation and application of new highly efficient and inexpensive photocatalytic materials.

关键词： Photocatalysis Hydrogen evolution Titania Cobalt sulphide Direct photodeposition

Study on the model of an insurer's solvency ratio in Markov-modulated Brownian markets

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Applied Mathematics(A Journal of Chinese Universities) 2011年第1期26卷 23-28页

作者： XIA Deng-feng fei Wei-yin LIANG Yong School of Mathematics and Physics Anhui Polytechnic University Wuhu 241000 China

In this paper the insurer＇s solvency ratio model with or without jump diffusion process in the presence of financial distress cost is constructed, where an insurer＇s solvency ratio is characterized by a Markov-modulated dynamics. By Girsanov＇s theorem and the option pricing formula, the expected present value of shareholders＇ terminal payoff is provided.

关键词： Markov-modulated market jump diffusion process solvency ratio Girsanov's theorem financialdistress cost.

A review of the end-effector of large space manipulator with capabilities of misalignment tolerance and soft capture

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Science China(Technological Sciences) 2016年第11期59卷 1621-1638页

作者： feng fei TANG LiNa XU Jianfeng LIU Hong LIU YiWe State Key Laboratory of Digital Manufacturing Equipment and Technology Huazhong University of Science and Technology (HUST) Wuhan 430074 China Shanghai Aerospace Equipments Manufacturer Shanghai 200245 China State Key Laboratory of Robotics and System Harbin Institute of Technology (HIT) Harbin 150080 China

The space manipulator which has advantages of high dexterity and universality, is used to the space capturing usually. According to the different types of mechanical interfaces of targets, the on orbit capturing operation includes capturing of cooperative target and capturing of uncooperative target. The performances of the famous large space manipulators named space shuttle remote manipulator system(SRMS), the space station remote manipulator system(SSRMS) and the Europe robotic arm(ERA) are reviewed and studied respectively. Moreover, the space manipulators being developed by China for space station is also surveyed. Based on the performance analysis of the large space manipulators and end-effectors, which are adapted to the construction and daily maintenance for the large space structure such as the space station, the basic requirements of large misalignment tolerance capability, soft capturing capability and hard docking capability for the end-effector of large space manipulator are proposed in this paper. According to these requirements, the capture mechanism and methods that can enable the end-effector to have the capability of misalignment tolerance and soft capturing are presented. The development trend and key technologies of the large space manipulators and the end-effectors are also reviewed.

关键词： space station large space manipulator end-effector large misalignment tolerance soft capture on-orbit capturing

Simulation and energy performance assessment of CO_2 removal from crude synthetic natural gas via physical absorption process

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Journal of Natural Gas Chemistry 2012年第6期21卷 633-638页

作者： Wanjun Guo fei feng Guohui Song Jun Xiao Laihong Shen Key Laboratory of Energy Thermal Conversion and Control of Ministry of Education School of Energy and EnvironmentSoutheast UniversityNanjing 210096JiangsuChina Department of Mechanical Technology Nanjing College of Chemical TechnologyNanjing 210048JiangsuChina

The paper presents an energy performance assessment of CO2 removal for crude synthetic natural gas （SNG） upgrade by Selexol absorption process. A simplified process simulation of the Selexol process concerning power requirement and separation performance was developed. The assessment indicates that less pressure difference between crude SNG and absorption pressure favors the energy performance of CO2 removal process. When both crude SNG and absorption pressures are 20 bar, CO2 removal process has the best energy performance. The optimal specific power consumption of the CO2 removal process is 566 kJ/kgCO2. The sensitivity analysis shows that the CO2 removal efficiency would significantly influence the total power consumption of the removal process, as well as higher heating value （HHV） and CO2 content in SNG. However, the specific power consumption excluding crude SNG and SNG compressions changes little with the variance of CO2 removal efficiency. If by-product CO2 is compressed for CO2 capture, the process would turn into a CO2-sink for the atmosphere. Correspondingly, an increase of 281 kJ/kgCO2 in specific power consumption is required for compressing the separated CO2.

关键词： CO2 removal physical absorption synthetic natural gas power consumption