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Investigation of ZSM-5/MCM-41 Composite Molecular Sieve for reducing Olefin Content of FCC Gasoline

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china petroleum processing & petrochemical technology 2009年第4期11卷 10-17页

作者： Ji Dekun~(1,2) Li Shuyuan~1 Ding Fuchen~2 Chi Yaoling~2 (1.Chemical Engineering school,china University of petroleum(beijing),beijing 102249 2.Department of Chemical Engineering,beijing institute of petrochemical technology) Chemical Engineering school China University of Petroleum (Beijing) Beijing 102249 China Department of Chemical Engineering Beijing Institute of Petrochemical Technology China

ZSM-5/MCM-41 composite molecular sieve was prepared by the nano-assembling *** ZSM-5 molecular sieve,the MCM-41 molecular sieve,the ZSM-5/MCM-41 mechanical mixture and the ZSM-5/MCM-41 composite molecular sieve were characterized by X-ray powder diffractometry,N_2 adsorption isotherms,temperature programmed desorption of ammonia and scanning electron microscopy and their properties were *** FCC gasoline as the feed,activities of different molecular sieves for reducing olefin content were investigated in a continuous high-pressure micro-reactor unit under the following conditions:a reaction temperature of 400℃,a reaction time of 2 h,a weight hourly space velocity of 3h^(-1),and a reaction pressure of 2.0 *** results showed that the HMCM-41 molecular sieve had low reaction performance,and the HZSM-5 molecular sieve demonstrated high aromatization activity,while the ZSM-5/MCM- 41 composite molecular sieve exhibited a best olefin-reducing performance because of its high isomerization activity and moderate aromatization *** a largest olefin-reducmg capability and a reasonable distribution of products,the composite molecular sieve was more suitable for FCC gasoline upgrading compared to other three catalysts.

关键词： ZSM-5 MCM-41 composite molecular sieve FCC gasoline olefin reduction

research on the Cutting performance of Cubic Boron Nitride Tools

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厦门大学学报（自然科学版） 2002年第S1期41卷 3-4页

作者： ZHENG Xiao-hua 1,2, YU Qi-xun 1, LIN Jing 1, LU Ming 2, pANG Si-qin 1 (1. school of Mechanical Engineering and automation, beijing institute of technology, beijing 100081, china 2. school of Mechanical Engineering, Taiyuan University of technology, Taiyuan 030024, china)

There were only two kinds of superhard tool material at the past, i.e. diamond and cubic boron nitride (CBN). Manmade diamond and CBN are manufactured by the middle of 20th century. Various manufacturing methods and manmade superhard materials were developed later. They were widely used in different industry and science areas. recently, a new kind of superhard tool material, C 3N 4 coating film, had been developed. American physical scientists, A. M. Liu and M. L. Cohen, designed a new kind of inorganic compound C 3N 4 with the theory of molecule engineering. According to calculation, it can reach or even exceed the hardness of diamond, so material scientists and technique circles draw their attention to it. A high speed steel twist drill coated with C 3N 4 film is applied to the drilling hole process on steel workpiece in cutting tests, the tool life is increased greatly. When the C 3N 4 film is coated on the cemented carbide inserts, the cutting performance is improved, but is not good enough. The data of mechanical performance and cutting tests about this kind of new tool material is given in this paper, it shows that C 3N 4 has a promising future. The anti-wear ability of cutting tool increases sharply after C 3N 4 being coated on HSS tool. Coated HSS drill also has some benefit after being reground. The tool life prolongs after C 3N 4 being coated on cemented carbide inserts, but is not so long as that of C 3N 4 coated HSS tool. When machining prCM with C 3N 4 thin-film coated cemented carbide tool, the cutting performance is poor and it is much better when machining prCM with pCBN, pCD compound plates and CVD thick-film coated cutting tool. Some relative aspects need to be deeply discussed and researched, e.g. the existing coating techniques is not good enough and should be improved in the future, the film thickness should be optimized and try to find out the most effective value, the binding force and mutual effect between coated film and substrate need to be

关键词： ultrahard material carbon nitride cutting tools cutting performance

Characteristics of Joint Welded by Laser Welding of Aluminium-Lithium Alloy with Filler Wire

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稀有金属材料与工程 2011年第S4期40卷 138-141页

作者： Yang J1,2,Li X Y1,Gong S L2,Chen L2,Xu F2 1 school of Material Science and Engineering,beijing University of technology,beijing 100083,china 2 Science and technology on power Beam processes Laboratory,beijing Aeronautical Manufacturing technology research institute,beijing 100024,china beijing Aeronaut Mfg Technol res Inst Sci & Technol Power Beam Proc Lab Beijing 100024 Peoples R China beijing Univ Technol Sch Mat Sci & Engn Beijing 100083 Peoples R China

The characteristics of weld shape,microstructure,mechanical properties and defects of 5A90 Al-Li alloy joint by laser welding (LBW) and laser welding with filler wire (LWFW) were studied and *** results indicated that the microstructure of joint by LWFW was fine-grained layer and the equiaxed grain in most of seams,which were similar to the joint by *** with the joint by LBW,the microstructure of joint by LWFW tended to fine,and the range of the columnar crystals zone was prone to *** Microhardness of the joint by LWFW (92.57HV0.2) was lower than that by LBW (95.65HV0.2),but the uniformity was *** ultimate tensile strength of the joint by LWFW was lower than that by LBW slightly,which reached to 73.03% and 79.22% of the base metal ***,the elongation of the LWFW joint was higher than that of the LBW joint significantly,which reached to 38.65% and 20.38% of the base metal *** microstructure and mechanical properties of 5A90 Al-Li alloy by LWFW were better than that by *** defects of joint were mainly forming defects which were caused by improper parameters and porosity inside the joint,which was caused by uncleaned surface and incomplete penetration.

关键词： Al-Li alloy laser beam welding (LBW) laser welding with filler wire (LWFW) weld shape microstructure mechani-cal properties defects

A Novel Medical robotic System for Laser-based Therapies

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A Novel Medical Robotic System for Laser-based Therapies

DESIGN CONSIDErATION OF ErBIUM DOpED FIBEr FOr EFFICIENT L-BAND EDFAs

第三十届中国控制会议

作者： LIU Xin-Ge school of automation,beijing institute of technology,beijing 100081,p.r.china

＜正＞port wine stain（pWS） birthmarks are congenital vascular malformations,which usually appear at birth and tend to become darker and thicker with age’s ***-targeted photodynamic therapy（pDT） is an effective approach in the treatment of ***,due to the arbitrariness of manual operation and existing pole points of laser radiation,the pWS zone was always cured unevenly in *** we developed a novel robotic system,which consists of passive arm and active wrist,to assist doctors in exerting pDT *** joints are easy to interface with doctors,safe and convenience;active joints can automate the pDT,so that let doctors focus on clinical judgements and the treatments rather than heave manual *** this paper,the mechanism of pWS and pDT were described in brief;the robotic system including the detailed robot mechanical design and kinematic analysis is discussed based on the requirements of pDT. Finally,the robot feasibility was validated by experimental results.

关键词： Medical robot passive Manipulator Kinematic Analysis

来源： cnki会议评论

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光子学报 2000年第12期29卷 1138-1140页

作者： Luo Jie,Ye peida school of Telecommunication Engineering,beijing University of posts and Telecommunications, beijing 100876,p.r.china Wu Shujian,Chen Shuling Wuhan research institute of posts and Telecommunications,Wuhan 430074,p.r.china school of Telecommunication Engineering Beijing University of Posts and Telecommunications Beijing 100876 China Wuhan research institute of posts and Telecommunications Wuhan 430074 China

In this paper,the relation between gain coefficient of long wavelength band(L band)EDFA and the Er 3+ ion concentration of erbium doped fiber (EDF) is *** high concentration EDF co doped with aluminium has been developed to shorten the fiber length necessary for L band amplification.L band amplification has been realized with a dual stage pumping *** the total EDF length of 18m,the small signal gain is 42.26dB and the output power is 17.5dBm at *** low concentration quenching effect is believed to be due to the high aluminium concentration in author ***-3dBm total input signal power,the gain tilt of 7 WDM channels from 1570 to 1600nm is only 0.68dB.

关键词： Erbium doped fiber L band EDFA Concentration quenching Gain flatness

The April 14th, 2010 Yushu earthquake, a devastating earthquake with foreshocks

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Science china Earth Sciences 2010年第6期53卷 791-793页

作者： NI SiDao1, WANG WeiTao2 & LI Li3 1 school of Earth and Space Sciences, University of Science and technology of china, Hefei 230026, china 2 institute of Geophysics, china Earthquake Administration, beijing 100081, china 3 National Earthquake Infrastructure Service, china Earthquake Administration, beijing 100036, china 1. school of Earth and Space Sciences University of Science and Technology of China Hefei 230026 China2. Institute of Geophysics China Earthquake Administration Beijing 100081 China3. National Earthquake Infrastructure Service China Earthquake Administration Beijing 100036 China

In the early morning of April 14th, 2010, a strong earth- quake (Ms7.1, http://***; Mw6.9, http://neic. ***) occurred in Yushu district, Qinghai province, china. More than 2000 lives were lost and over 100000 injured,

关键词： Figure Yushu earthquake a devastating earthquake with foreshocks The April 14th 2010 very than

persistent anomalous flows over the subtropical western pacific insummer

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Chinese Science Bulletin 1998年第8期43卷 672-675页

作者： ZHUANG Shiyu\+1 and JI Liren\+2 1. National Meteorological Centre, china Meteorological Administration, beijing 100081, china 2. LASG, institute of Atmospheric physics, Chinese Academy of Sciences, beijing 100080, china National Meteorological Ccntre China Meteomlcgical Administration Beijing China LASG Institute of Atmospheric Physics Chinese Academy of Sciences Beijing China

The distribution of global persistent anomalies shows that the subtropical western pacific is a key region with high_frequency occurrence of persistent anomalies. Analyses of streamfunction anomalies, OLr anomalies etc. suggest that the convective heating related to Indian monsoon might be responsible for the development of WpA. The results of numerical experiment by two linear barotropic models support the observation.

关键词： persistent anomalies subtropical high Indian monsoon anomalous forcing.

prediction-based guidance algorithm for high-lift reentry vehicles

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Science china(Information Sciences) 2011年第3期54卷 498-510页

作者： ZHANG Zhao 1,2 & HU Jun 1 1 beijing institute of Control Engineering, beijing 100190, china 2 Science and technology on Space Intelligent Control Laboratory, beijing 100190, china 1. beijing institute of Control Engineering Beijing 100190 China2. Science and Technology on Space Intelligent Control Laboratory Beijing 100190 China

In this work, we propose a pseudo four-degrees-of-freedom (DOF) prediction based guidance algo- rithm specifically for high-lift reentry vehicles. The algorithm is composed mainly of three parts. First, at the beginning of each guidance cycle, the 4-DOF predictor is called upon to predict the final downrange, crossrange, and heading errors. Then, the magnitude of the bank angle is determined from the downrange error, using the proportional-integral (pI) control method. Finally, two bank angle reversal time points are determined to minimize the crossrange and heading errors. Compared with traditional predictor-corrector guidance, the algorithm proposed does not require iterative procedures which significantly decreases the computational burden for the on-board computer and makes the implementation practical. Simulation results for dispersion tests demonstrated that our algorithm is computationally efficient and robust against uncertainties and disturbances.

关键词： pseudo 4-DOF prediction-based guidance high-lift reentry vehicle

Stability analysis of a hypersonic vehicle controlled by the characteristic model based adaptive controller

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Science china(Information Sciences) 2012年第10期55卷 2243-2256页

作者： ZHANG Zhao 1,2 & HU Jun 1 1 beijing institute of Control Engineering,beijing 100190,china 2 Science and technology on Space Intelligent Control Laboratory,beijing 100190,china 1. beijing institute of Control Engineering Beijing 100190 China2. Science and Technology on Space Intelligent Control Laboratory Beijing 100190 China

The closed loop attitude stability of a hypersonic vehicle controlled by the characteristic model-based all-coefficient adaptive controller is studied in this paper,and an algorithm based on the computation of induced matrix 1-norm or ∞-norm is *** of all,the Taylor series expansion is applied to discretize the inputoutput description of the attitude dynamics of the *** obtained difference equations have the same structure as characteristic model;thus the intervals which contain all possible values of certain characteristic model parameters are *** the linear feedback controller is used in the feedback loop,with some conservation,the closed loop system is viewed as a class of interval time-varying systems defined by a number of free time-varying *** free parameters take values from predefined *** sufficient and necessary condition for the stability of this class of system is ***,a sufficient condition for the stability of hypersonic vehicle attitude control loop is proposed and demonstration example is *** method proposed checks up the stability of the closed loop system by evaluating a finite number of matrix norms,and overcomes the difficulties brought by the time-varying nature of the characteristic model and parameter estimation.

关键词： characteristic model hypersonic vehicle interval time-varying system stability test attitude control