期刊文献+
共找到15篇文章
< 1 >
每页显示 20 50 100
Exact Traveling Wave Solutions for a Kind of Generalized Ginzburg-Landau Equation 被引量:8
1
作者 LIUCheng-Shi 《Communications in Theoretical Physics》 SCIE CAS CSCD 2005年第5期787-790,共4页
Using a complete discrimination system for polynomials, new exact traveling wave solutions for generalized Ginzburg-Landau equation are obtained. The method has general meaning for many similar problems.
关键词 generalized Ginzburg-Landau equation elementary integral method polynomialcomplete discrimination system
下载PDF
Microstructure and Property of High Carbonic-Chromium Cast Steel with Different Hot Deformation Ratio 被引量:3
2
作者 XUTao WANGJiu-liang +2 位作者 ZHANGRun-jun CHAOGuo-hua LIUJian-hua 《Journal of Iron and Steel Research International》 SCIE EI CAS CSCD 2004年第1期37-41,共5页
The microstructure and properties of high carbonic-chromium cast steel subjected to different hot deformation ratios were studied.The experimental results show that the microstructure and properties of high carbonic-c... The microstructure and properties of high carbonic-chromium cast steel subjected to different hot deformation ratios were studied.The experimental results show that the microstructure and properties of high carbonic-chromium cast steel are obviously improved after hot deformation,and the best mechanical properties of the cast steel can be obtained under hot deformation ratio of 40 %-50 %,which leads to the morphology change of eutectic carbide and the precipitation of granular carbides. 展开更多
关键词 high carbonic-chromium cast steel hot deformation ratio microstructure mechan-ical property
下载PDF
Application of gap element to nonlinear mechanics analysis of drillstring 被引量:2
3
作者 刘巨保 丁皓江 张学鸿 《Journal of Zhejiang University Science》 CSCD 2002年第4期440-444,共5页
This paper presents a nonlinear finite element method to resolve the problem of the nonlinear contact between the drillstring and hole wall by using a Multi-directional Contact Gap Element (MCGE) contacting at appropr... This paper presents a nonlinear finite element method to resolve the problem of the nonlinear contact between the drillstring and hole wall by using a Multi-directional Contact Gap Element (MCGE) contacting at appropriate positions in each beam element. The method was successfully applied to the Daqing Oil Field GP1 well. It was shown that the drillstring's contact resistance at any well depth could be obtained by calculations and that as the error in the calculation of the hole top load is below 10%, the calculation result can provide theoretical basis for the design and operation of drillstrings. 展开更多
关键词 Drillstring Contact non-line Finite element Horizontal well
下载PDF
Selective Oxidation of Propane by Lattice Oxygen of Vanadium-Phosphorous Oxide in a Pulse Reactor 被引量:1
4
作者 RusongZhao JianWang +1 位作者 QunDong JianhongLiu 《Journal of Natural Gas Chemistry》 EI CAS CSCD 2005年第2期88-94,共7页
Selective oxidation of propane by lattice oxygen of vanadium-phosphorus oxide(VPO) catalysts was investigated with a pulse reactor in which the oxidation of propane and there-oxidation of catalyst were implemented alt... Selective oxidation of propane by lattice oxygen of vanadium-phosphorus oxide(VPO) catalysts was investigated with a pulse reactor in which the oxidation of propane and there-oxidation of catalyst were implemented alternately in the presence of water vapor. The principalproducts are acrylic acid (AA), acetic acid (HAc), and carbon oxides. In addition, small amounts ofC_1 and C_2 hydrocarbons were also found, molar ratio of AA to HAc is 1.4-2.2. The active oxygenspecies are those adsorbed on catalyst surface firmly and/or bound to catalyst lattice, i.e. latticeoxygen; the selective oxidation of propane on VPO catalysts can be carried out in a circulatingfluidized bed (CFB) riser reactor. For propane oxidation over VPO catalysts, the effects of reactiontemperature in a pulse reactor were found almost the same as in a steady-state flow reactor. Thatis, as the reaction temperature increases, propane conversion and the amount of C_1+C_2 hydrocarbonsin the product increase steadily, while selectivity to acrylic acid and to acetic acid increaseprior to 350℃ then begin to drop at temperatures higher than 350℃, and yields of acrylic acid andof acetic acid attained maximum at about 400℃. The maximum yields of acrylic acid and of aceticacid for a single-pass are 7.50% and 4.59% respectively, with 38.2% propane conversion. When theamount of propane pulsed decreases or the amount of catalyst loaded increases, the conversionincreases but the selectivity decreases. Increasing the flow rate of carrier gases causes theconversion pass through a minimum but selectivity and yields pass through a maximum. In a fixed bedreactor, it is hard to obtain high selectivity at a high reaction conversion due to the furtherdegradation of acrylic acid and acetic acid even though propane was oxidized by the lattice oxygen.The catalytic performance can be improved in the presence of excess propane. Propylene can beoxidized by lattice oxygen of VPO catalyst at 250℃, nevertheless, selectivity to AA and to HAc areeven lower, much more acetic acid was produced (molar ratio of AA to HAc is 0.19:1-0.83:1) thoughthe oxidation products are the same as from propane. 展开更多
关键词 propane oxidation acrylic acid acetic acid vanadium-phosphorus oxide lattice oxygen oxidation pulse reaction
下载PDF
Synthesis and Characterization of a One-dimensional Chain Polymer{[Cu(4-CPOA)(3-PyOH)_2(H_2O)_2]·H_2O}_n 被引量:1
5
作者 GAOShan HUOLi-Hua +3 位作者 LIUJi-Wei GUChang-Sheng ZHAOHui ZHAOJing-Gui 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 北大核心 2005年第7期755-758,735,共5页
A novel one-dimensional copper(II) coordination polymer of {[Cu(4-CPOA)(3- PyOH)2(H2O)2]?H2O}n (4-CPOA2– = 4-carboxyphenoxyacetate dianion, 3-PyOH = 3-hydroxypyri- dine) has been synthesized and characterized by elem... A novel one-dimensional copper(II) coordination polymer of {[Cu(4-CPOA)(3- PyOH)2(H2O)2]?H2O}n (4-CPOA2– = 4-carboxyphenoxyacetate dianion, 3-PyOH = 3-hydroxypyri- dine) has been synthesized and characterized by elemental analyses, IR spectra and single-crystal X-ray diffraction. The complex C19H22N2O10Cu crystallizes in triclinic system, space group P1 with a = 7.672(2), b = 18.490(4), c = 13.271(3) ?, α = 72.81(3), β = 84.64(3), γ = 87.28(3)o, V = 1026.3(4) ?3, Z = 2, Mr = 501.94, Dc = 1.624 g/cm3, μ = 1.126 mm–1, F(000) = 518, the final R = 0.0580 and wR = 0.1310 for 3364 observed reflections with I > 2σ(I). Each Cu(II) ion is coordinated with two different carboxyl O atoms from two 4-carboxyphenoxyacetate groups, two N atoms from two 3-PyOH ligands and two water molecules, residing in a distorted octahedral environment. Adjacent Cu(II) atoms are linked by bi-monodentate 4-CPOA2– groups into an one-dimensional chain along the b axis. A three-dimensional supramolecular network is constructed by O–H…O hydrogen bonds. 展开更多
关键词 copper(II) carboxylate coordination polymer synthesis crystal structure
下载PDF
Travelling Wave Solutions of Triple Sine-Gordon Equation 被引量:6
6
作者 刘成仕 《Chinese Physics Letters》 SCIE CAS CSCD 2004年第12期2369-2371,共3页
下载PDF
Remove Bertrand's Paradox by Means of Invariant Measure 被引量:1
7
作者 LIUCheng-shi DUXing-hua WANGShou-tian 《大学数学》 2004年第2期53-56,共4页
By means of invariant measure, Bertrand's paradox was removed.
关键词 Bertrand's PARADOX INVARIANT measure GEOMETRICAL probability INTEGRAL geometry
下载PDF
A New Mathematical Simulation Approach for Thermal Cracking Furnace Studies
8
作者 LanXingying XuChunming +1 位作者 GaoJinsen ZhangHongmei 《Petroleum Science》 SCIE CAS CSCD 2005年第1期37-43,共7页
Thermal cracking of hydrocarbons for olefin production is normally carried out in long reactor tubes suspended in a large gas fired furnace. In this paper, a coupled furnace-reactor mathematical model based on a com... Thermal cracking of hydrocarbons for olefin production is normally carried out in long reactor tubes suspended in a large gas fired furnace. In this paper, a coupled furnace-reactor mathematical model based on a computational fluid dynamics (CFD) technique is developed to simulate the complex fluid dynamics phenomena in the thermal cracking furnace. The model includes mass transfer, momentum transfer, and heat transfer, as well as thermal cracking reactions, fuel combustion and radiative heat transfer. The rationality and reliability of the mathematical model is confirmed by the approximate agreement of predicted data and industrial data. The coupled furnace-reactor simulation revealed the details of both the transfer and reaction processes taking place in the thermal cracking furnace. The results indicate highly nonuniform distribution of the flue-gas velocity, concentration and temperature in the furnace, which cause nonuniform distribution of tube skin temperature and heat flux of the reactor tubes. Profiles of oil-gas velocity, pressure, temperature and product yields in the lengthwise direction of the reactor tube are obtained. Furthermore, in the radial direction steep velocity and temperature gradients and relatively slight gradients of species concentration are found. In conclusion, the model can provide more information on the fluid dynamics and reaction behavior in the thermal cracking furnace, and guidance for the design and improvement of thermal cracking furnaces. 展开更多
关键词 Thermal cracking furnace computational fluid dynamics numerical simulation VELOCITY TEMPERATURE species concentration heat flux
下载PDF
Robust L_1 filtering with pole constraint in a disk via parameter-dependent Lyapunov functions
9
作者 LiYanhui WenQiyong +2 位作者 WangJunling WangChanghong GaoHuijun 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2005年第1期102-109,共8页
The problem of robust L 1 filtering with pole constraint in a disk for linear continuous polytopic uncertain systems is discussed. The attention is focused on design a linear asymptotically stable filter such that th... The problem of robust L 1 filtering with pole constraint in a disk for linear continuous polytopic uncertain systems is discussed. The attention is focused on design a linear asymptotically stable filter such that the filtering error system remains robustly stable, and has a L 1 performance constraint and pole constraint in a disk. The new robust L 1 performance criteria and regional pole placement condition are obtained via parameter-dependent Lyapunov functions method. Upon the proposed multiobjective performance criteria and by means of LMI technique, both full-order and reduced-order robust L 1 filter with suitable dynamic behavior can be obtained from the solution of convex optimization problems. Compared with earlier result in the quadratic framework, this approach turns out to be less conservative. The efficiency of the proposed technique is demonstrated by a numerical example. 展开更多
关键词 robust filtering parameter-dependent Lyapunov function linear matrix inequality L 1 performance pole placement technique.
下载PDF
Integration Between Enterprise Process Monitoring and Controlling System and Enterprise Application
10
作者 WENBi-long ZHANGLi WANGXiao-hua 《Wuhan University Journal of Natural Sciences》 EI CAS 2005年第3期566-571,共6页
The relationships and the features of integration between Enterprise ProcessMonitoring and Controlling System (EPMCS) and Enterprise Process Related Applications (EPRA) wereanalyzed. An integration architecture center... The relationships and the features of integration between Enterprise ProcessMonitoring and Controlling System (EPMCS) and Enterprise Process Related Applications (EPRA) wereanalyzed. An integration architecture centered on EPMCS was presented, in which there were fourlayers to connect from EPMCS to EPRA: EPMCS, application integration layer, transport layer andEPRA, and there were four layers used to etstablish integration: presentation layer, function layer,data layer and system layer. The frameworks to connect EPMCS and EPRA were designed, thatEnterprise-Independent Model (EIM), Enterprise-Specific Model (ESM) and meta-model to describe thesetwo models were defined. The method to integrate data based on XML was designed to exchange datafrom EPMCS to EPRA according to the mapping between EIM and ESM. The approches are suitable forintegrating EPMCS and systems in Product Data Management (PDM), project management and enterprisebusiness management. 展开更多
关键词 enterprise process model process monitoring and controlling enterpriseapplication integration model driven architecture
下载PDF
Effect of Rare Earth Element on Formation and Propagation of Thermal Fatigue Crack in Low-Chromium Semi-Steel
11
作者 XUTao LIFeng +1 位作者 CHENHua YUCui-yan 《Journal of Iron and Steel Research International》 SCIE CAS CSCD 2005年第4期40-43,49,共5页
The formation and growth of thermal fatigue crack in low-chromium semi-steel were investigated by means of optical microscope and scanning electron microscope, and the function of RE in low-chromium semi-steel was ana... The formation and growth of thermal fatigue crack in low-chromium semi-steel were investigated by means of optical microscope and scanning electron microscope, and the function of RE in low-chromium semi-steel was analyzed. The results show that the thermal fatigue cracks are mainly generated at eutectic carbides, and the cracks not only grow and spread but also join each other. RE can improve the eutectic carbide′s morphology, inhibit the generation and propagation of thermal fatigue cracks, and therefore promote the activation energy for the crack′s propagation, which is especially more noticeable in case of the RE modification in combination with heat treatment. The mathematical model of the crack propagation is put forward. 展开更多
关键词 RE low-chromium semi-steel thermal fatigue crack
下载PDF
The Mechanism and Usage for Enhanced Oil Recovery by Chemotaxis of Bacterium BS2
12
作者 LiYiqian JingGuicheng +1 位作者 GaoShusheng XungWei 《工程科学(英文版)》 2005年第1期38-42,共5页
Due to its chemotaxis, the motion ability of bacterium BS2 is very strong, and under the microscope, the distribution grads of bacterium concentration can be seen at the oil-water interface.During the experiments in g... Due to its chemotaxis, the motion ability of bacterium BS2 is very strong, and under the microscope, the distribution grads of bacterium concentration can be seen at the oil-water interface.During the experiments in glass box, it can be observed, with eyes, because of the chemotaxis, that muddy gets thicker and thicker at the interface gradually, and it is measured there, from sampling, that the bacterium concentration is 10 9 cells/mL, pH value 4.4 and the concentration of bio-surfactant 2.87%; The microbial oil-displacement experiments are carried out in emulational network models, and the oil-displacement mechanism by the bacterium and its metabolizing production is studied. And, during oil-displacement experiments in the gravel-input glass models, because of the profile control of thalli and the production, the sweep area of subsequent waterflood becomes wider, which can be seen with eyes and the recovery is enhanced by 13.6%. Finally, the successful field test is introduced in brief: the ratio of response producers is 85.7%, and the water-cut degrades by 6.4%, while 20038 t oil has increased in accumulative total in 2 years. 展开更多
关键词 MEOR 细菌分布 趋药性 位移机构 BS2 石油
下载PDF
PRESSURE TRANSIENT ANALYSIS OF HETEROGENOUS RESERVOIRS WITH IMPERMEABILITY BARRIER USING PERTURBATION BOUNDARY ELEMENT METHOD 被引量:10
13
作者 YINHong-jun HEYing-fu FUChun-quan 《Journal of Hydrodynamics》 SCIE EI CSCD 2005年第1期102-109,共8页
The transient flow mathematical model of arbitrary shaped heterogeneous reservoirs with impermeability barrier is proposed in this paper. In order to establish this model, the perturbation method is employed and the s... The transient flow mathematical model of arbitrary shaped heterogeneous reservoirs with impermeability barrier is proposed in this paper. In order to establish this model, the perturbation method is employed and the solution of model is expanded into a series in powers of perturbation parameter. By using the Boundary Element Method (BEM) and Duhamel principle, wellbore pressure with effects of skins and wellbore storage is obtained. The type curves are plotted and analyzed considering effects of heterogeneity, arbitrary shape and impermeable barriers. Finally, the results obtained by perturbation boundary element method is compared with the analytical solution and is available for the transient pressure analysis of arbitrary shaped reservoirs. 展开更多
关键词 heterogeneous reservoirs arbitrary shape impermeable barrier perturbation equation boundary element method pressure transient analysis type curves
原文传递
AN UNSTEADY SEEPAGE FLOW MODEL OF VISCO-ELASTIC POLYMER SOLUTION 被引量:5
14
作者 YINHong-jun LVYan-ping 《Journal of Hydrodynamics》 SCIE EI CSCD 2004年第2期209-215,共7页
With the consideration of the visco―elasticity, the adsorption effect andthe variation of rheological parameters, a seepage flow model of visco-elastic polymer solutions wasestablished. The model was numerically trea... With the consideration of the visco―elasticity, the adsorption effect andthe variation of rheological parameters, a seepage flow model of visco-elastic polymer solutions wasestablished. The model was numerically treated with the finite difference method. Then curves ofBottom Hole Pressure (BHP) and formation pressure were drawn. The influences of the relaxation time,the injection rate, the permeability reduction coefficient, the consistency coefficient and thepower-law exponent of the injected fluid on pressure performance were analyzed. This study showsthat it is necessary to consider the visco-elasticity of non-Newtonian fluid in analyzing ofpressure performance in the polymer flooding. 展开更多
关键词 polymer solution rheological property VISCO-ELASTICITY seepage flow model
原文传递
THE PRODUCTIVITY OF WELL PATTERN WITH HORIZONTAL WELLS AND VERTICAL WELLS 被引量:3
15
作者 ZhaoChun-sen CuiHai-qing +1 位作者 SongWen-ling ZhangZhen 《Journal of Hydrodynamics》 SCIE EI CSCD 2003年第5期60-64,共5页
The calculation of productivity and the choice of well pattern of mixedhorizontal and vertical wells were discussed in this paper. Because the naturall drainage areas ofhorizontal wells are oval rather than circular, ... The calculation of productivity and the choice of well pattern of mixedhorizontal and vertical wells were discussed in this paper. Because the naturall drainage areas ofhorizontal wells are oval rather than circular, rectangular drainage well patterns should beadopted. Using pseudo 3-di-mensional method and conformal transformation, the potential function ofa row of horizontal wells was deduced. Using this function and the superposition principle, ananalytical solution of the productivity for the rectangular mixed well pattern was given.Quantitative means for defining the shapes of the optimum pattern were developed in this paper byintroducing two dimensionless parameters, the shape factor and dimensionless length of horizontalwell. The formula for productvity was used to optimize the mixed well patterns. The curves of theoptimized shape factor against dimensionless length of horizontal well were drawn. The results showthat the pattern area and formation thickness have no effect on the optimal shape factors and can beapplied to the design of development for oil fields. 展开更多
关键词 horizontal well vertical well rectangular staggered well pattern PRODUCTIVITY optimum pattern
原文传递
上一页 1 下一页 到第
使用帮助 返回顶部