期刊文献+
共找到857篇文章
< 1 2 43 >
每页显示 20 50 100
A Study on the Work Process-Based Practical Training Model for Basic Nursing Skills in Vocational Colleges
1
作者 Dan Li Huan Wei 《Journal of Clinical and Nursing Research》 2024年第9期128-132,共5页
Objective:To explore and analyze the work process-based practical training teaching model for basic nursing skills in vocational colleges and its implementation effects.Methods:A total of 82 nursing students from our ... Objective:To explore and analyze the work process-based practical training teaching model for basic nursing skills in vocational colleges and its implementation effects.Methods:A total of 82 nursing students from our school were selected for the study,which was conducted from April 2023 to April 2024.Using a random number table method,the students were divided into an observation group and a control group,each with 41 students.The control group received conventional practical training teaching,while the observation group followed the work process-based practical training model for basic nursing skills.The assessment scores and teaching satisfaction of the two groups were compared.Results:The comparison of assessment scores showed that the observation group performed significantly better than the control group(P<0.05).The comparison of teaching satisfaction also indicated that the observation group had significantly higher satisfaction than the control group(P<0.05).Conclusion:The work process-based practical training teaching model for basic nursing skills in vocational colleges can improve students’assessment scores and enhance teaching satisfaction,demonstrating its value for wider application. 展开更多
关键词 Work processes Vocational colleges Basic nursing skills Practical training teaching model
下载PDF
Modeling of microstructure evolution of AZ80 magnesium alloy during hot working process using a unified internal state variable method 被引量:5
2
作者 Zexing Su Chaoyang Sun +2 位作者 Mingjia Wang Lingyun Qian Xintong Li 《Journal of Magnesium and Alloys》 SCIE EI CAS CSCD 2022年第1期299-313,共15页
In this paper, a unified internal state variable(ISV) model for predicting microstructure evolution during hot working process of AZ80 magnesium alloy was developed. A novel aspect of the proposed model is that the in... In this paper, a unified internal state variable(ISV) model for predicting microstructure evolution during hot working process of AZ80 magnesium alloy was developed. A novel aspect of the proposed model is that the interactive effects of material hardening, recovery and dynamic recrystallization(DRX) on the characteristic deformation behavior were considered by incorporating the evolution laws of viscoplastic flow, dislocation activities, DRX nucleation and boundary migration in a coupled manner. The model parameters were calibrated based on the experimental data analysis and genetic algorithm(GA) based objective optimization. The predicted flow stress, DRX fraction and average grain size match well with experimental results. The proposed model was embedded in the finite element(FE) software DEFORM-3 D via user defined subroutine to simulate the hot compression and equal channel angular extrusion(ECAE) processes. The heterogeneous microstructure distributions at different deformation zones and the dislocation density evolution with competitive deformation mechanisms were captured.This study can provide a theoretical solution for the hot working problems of magnesium alloy. 展开更多
关键词 AZ80 magnesium alloy Internal state variable model Microstructure evolution Dynamic recrystallization Hot working process Finite element simulation
下载PDF
Parametric Linear Stochastic Modelling of Benue River flow Process 被引量:1
3
作者 Otache . Y. Martins +1 位作者 I. E. Ahaneku M. A. Sadeeq 《Open Journal of Marine Science》 2011年第3期73-81,共9页
The dynamics and accurate forecasting of streamflow processes of a river are important in the management of extreme events such as floods and droughts, optimal design of water storage structures and drainage networks.... The dynamics and accurate forecasting of streamflow processes of a river are important in the management of extreme events such as floods and droughts, optimal design of water storage structures and drainage networks. In this study, attempt was made at investigating the appropriateness of stochastic modelling of the streamflow process of the Benue River using data-driven models based on univariate streamflow series. To this end, multiplicative seasonal Autoregressive Integrated Moving Average (ARIMA) model was developed for the logarithmic transformed monthly flows. The seasonal ARIMA model’s performance was compared with the traditional Thomas-Fiering model forecasts, and results obtained show that the multiplicative seasonal ARIMA model was able to forecast flow logarithms. However, it could not adequately account for the seasonal variability in the monthly standard deviations. The forecast flow logarithms therefore cannot readily be transformed into natural flows;hence, the need for cautious optimism in its adoption, though it could be used as a basis for the development of an Integrated Riverflow Forecasting System (IRFS). Since forecasting could be a highly “noisy” application because of the complex river flow system, a distributed hydrological model is recommended for real-time forecasting of the river flow regime especially for purposes of sustainable water resources management. 展开更多
关键词 STOCHASTIC process Water RESOURCES Dynamics RIVER flow modelling
下载PDF
Modeling study on the flow patterns of gas–liquid flow for fast decarburization during the RH process 被引量:2
4
作者 Yi-hong Li Yan-ping Bao +2 位作者 Rui Wang Li-feng Ma Jian-sheng Liu 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2018年第2期153-163,共11页
A water model and a high-speed video camera were utilized in the 300-t RH equipment to study the effect of steel flow patterns in a vacuum chamber on fast decarburization and a superior flow-pattern map was obtained d... A water model and a high-speed video camera were utilized in the 300-t RH equipment to study the effect of steel flow patterns in a vacuum chamber on fast decarburization and a superior flow-pattern map was obtained during the practical RH process. There are three flow patterns with different bubbling characteristics and steel surface states in the vacuum chamber: boiling pattern(BP), transition pattern(TP), and wave pattern(WP). The effect of the liquid-steel level and the residence time of the steel in the chamber on flow patterns and decarburization reaction were investigated, respectively. The liquid-steel level significantly affected the flow-pattern transition from BP to WP, and the residence time and reaction area were crucial to evaluate the whole decarburization process rather than the circulation flow rate and mixing time. A superior flow-pattern map during the practical RH process showed that the steel flow pattern changed from BP to TP quickly, and then remained as TP until the end of decarburization. 展开更多
关键词 modeling study flow pattern vacuum chamber residence time decarburization RH process
下载PDF
Digital image processing of saturation for two-phase flow in planar porous media model
5
作者 Zhi DOU Zhi-fang ZHOU +1 位作者 Si WANG Yong HUANG 《Water Science and Engineering》 EI CAS 2012年第2期202-209,共8页
In this paper, the accuracy of estimating stained non-wetting phase saturation using digital image processing is examined, and a novel post-processing approach for calculating threshold is presented. In order to remov... In this paper, the accuracy of estimating stained non-wetting phase saturation using digital image processing is examined, and a novel post-processing approach for calculating threshold is presented. In order to remove the effect of the background noise of images and to enhance the high-frequency component of the original image, image smoothing and image sharpening methods are introduced. Depending on the correct threshold, the image binarization processing is particularly useful for estimating stained non-wetting phase saturation. Calculated saturation data are compared with the measured saturation data during the two-phase flow experiment in an artificial steel planar porous media model. The results show that the calculated saturation data agree with the measured ones. With the help of an artificial steel planar porous media model, digital image processing is an accurate and simple method for obtaining the stained non-wetting phase saturation. 展开更多
关键词 digital image processing saturation two-phase flow planar porous media model
下载PDF
Stochastic Modelling of Great Letaba River Flow Process
6
作者 Gislar E. Kifanyi Julius M. Ndambuki +1 位作者 Samuel N. Odai Charles Gyamfi 《Journal of Geoscience and Environment Protection》 2019年第6期42-54,共13页
A stochastic approach is presented in view that a time series modelling is achieved through an Autoregressive Moving Average (ARMA) model. The applicability of the ARMA model is then further presented using the Great ... A stochastic approach is presented in view that a time series modelling is achieved through an Autoregressive Moving Average (ARMA) model. The applicability of the ARMA model is then further presented using the Great Letaba River as a case study. River flow discharge for 25 years (1989-2014) for the Great Letaba River was obtained from the Department of Water and Sanitation, South Africa and analysed by Autoregressive (AR), Autoregressive Moving Average (ARMA) and Autoregressive Integrated Moving Average (ARIMA) models. Monte Carlo simulation approach was used to generate forecasts of the ARIMA error model for the next 25 years. Initial model identification was done using the Autocorrelation function (ACF) and Partial Autocorrelation function (PACF). The model analysis and evaluations provided proper predictions of the river system. The models revealed some degree of correlation and seasonality behaviour with decreasing river flow. Hence, in conclusion, the Great Letaba River flow has shown a decreasing trend and therefore, should be effectively used for sustainable future development. 展开更多
关键词 modelling GREAT Letaba RIVER SOUTH AFRICA STOCHASTIC flow process
下载PDF
Physical and Mathematical Modeling of the Argon-Oxygen Decarburization Refining Process of Stainless Steel 被引量:5
7
作者 魏季和 《Journal of Shanghai University(English Edition)》 CAS 2002年第1期1-23,共23页
The available studies in the literature on physical and mathematical modeling of the argon oxygen decarburization (AOD) process of stainless steel have briefly been reviewed. The latest advances made by the author wi... The available studies in the literature on physical and mathematical modeling of the argon oxygen decarburization (AOD) process of stainless steel have briefly been reviewed. The latest advances made by the author with his research group have been summarized. Water modeling was used to investigate the fluid flow and mixing characteristics in the bath of an 18 t AOD vessel, as well as the 'back attack' action of gas jets and its effects on the erosion and wear of the refractory lining, with sufficiently full kinematic similarity. The non rotating and rotating gas jets blown through two annular tuyeres, respectively of straight tube and spiral flat tube type, were employed in the experiments. The geometric similarity ratio between the model and its prototype (including the straight tube type tuyeres) was 1:3. The influences of the gas flow rate, the angle included between the two tuyeres and other operating parameters, and the suitability of the spiral tuyere as a practical application, were examined. These latest studies have clearly and successfully brought to light the fluid flow and mixing characteristics in the bath and the overall features of the back attack phenomena of gas jets during the blowing, and have offered a better understanding of the refining process. Besides, mathematical modeling for the refining process of stainless steel was carried out and a new mathematical model of the process was proposed and developed. The model performs the rate calculations of the refining and the mass and heat balances of the system. Also, the effects of the operating factors, including adding the slag materials, crop ends, and scrap, and alloy agents; the non isothermal conditions; the changes in the amounts of metal and slag during the refining; and other factors were all considered. The model was used to deal with and analyze the austenitic stainless steel making (including ultra low carbon steel) and was tested on data of 32 heats obtained in producing 304 grade steel in an 18 t AOD vessel. The changes in the bath composition and temperature during the refining process with time can be accurately predicted using this model. The model can provide some very useful information and a reliable basis for optimizing the process practice of the refining of stainless steel and control of the process in real time and online. 展开更多
关键词 stainless steel argon oxygen decarburization (AOD) process fluid flow and mixing back attack phenomenon non rotating and rotating gas jets DECARBURIZATION water modeling mathematical modeling.
下载PDF
Mathematical simulation of hot metal desulfurization during KR process coupled with an unreacted core model 被引量:6
8
作者 Yanyu Zhao Wei Chen +1 位作者 Shusen Cheng Lifeng Zhang 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2022年第4期758-766,共9页
A three-dimensional mathematical model was established to predict the multiphase flow,motion and dispersion of desulfurizer particles,and desulfurization of hot metal during the Kanbara reactor(KR)process.The turbulen... A three-dimensional mathematical model was established to predict the multiphase flow,motion and dispersion of desulfurizer particles,and desulfurization of hot metal during the Kanbara reactor(KR)process.The turbulent kinetic energy-turbulent dissipation rate(k-ε)turbulence model,volume-of-fluid multiphase model,discrete-phase model,and unreacted core model for the reaction between the hot metal and particles were coupled.The measured sulfur content of the hot metal with time during the actual KR process was employed to validate the current mathematical model.The distance from the lowest point of the liquid level to the bottom of the ladle decreased from 3170 to2191 mm when the rotation speed increased from 30 to 110 r/min,which had a great effect on the dispersion of desulfurizer particles.The critical rotation speed for the vortex to reach the upper edge of the stirring impeller was 70 r/min when the immersion depth was 1500 mm.The desulfurization rate increased with the increase in the impeller rotation speed,whereas the influence of the immersion depth was relatively small.Formulas for different rotation parameters on the desulfurization rate constant and turbulent energy dissipation rate were proposed to evaluate the variation in sulfur content over time. 展开更多
关键词 DESULFURIZATION unreacted core model desulfurizer dispersion KR process fluid flow
下载PDF
Physical Modeling of the Vacuum Circulation Refining Process of Molten Steel 被引量:5
9
作者 魏季和 《Journal of Shanghai University(English Edition)》 CAS 2003年第1期1-17,共17页
The available studies in the literature on physical modeling of the vacuum circulation (RH, i.e. Ruhrstahl Heraeus) refining process of molten steel have briefly been reviewed. The latest advances made by the author ... The available studies in the literature on physical modeling of the vacuum circulation (RH, i.e. Ruhrstahl Heraeus) refining process of molten steel have briefly been reviewed. The latest advances made by the author with his research group have been summarized. Water modeling was employed to investigate the flow and mixing characteristics of molten steel under the RH and RH KTB (Kawasaki top blowing) conditions and the mass transfer features between molten steel and powder particles in the RH PTB (powder top blowing) refining. The geometric similarity ratio between the model and its prototype (a multifunction RH degasser of 90 t capacity) was 1:5. The effects of the related technological and structural factors were considered. These latest studies have revealed the flow and mixing characteristics of molten steel and the mass transfer features between molten steel and powder particles in these processes, and have provided a better understanding of the refining processes of molten steel. 展开更多
关键词 vacuum circulation refining RH process RH KTB (Kawasaki top blowing) process RH PTB (powder top blowing) process flow mixing mass transfer characteristics between molten steel and particles water modeling
下载PDF
A mathematical model capable of describing the liquid flow mainly in a blast furnace 被引量:1
10
作者 Cheng-shan Wang Xiao-jing Mu 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2009年第5期505-511,共7页
The molten liquid flow inside a packed bed is a familiar momentum transportation phenomenon in a blast furnace. With regard to the reported mathematical models describing the liquid flow within a packed bed, there are... The molten liquid flow inside a packed bed is a familiar momentum transportation phenomenon in a blast furnace. With regard to the reported mathematical models describing the liquid flow within a packed bed, there are some obstacles for their application in engineering design, or some limitations in the model itself. To overcome these problems, the forces from the packed bed to the liquid flow were divided into appropriate body and surface forces on the basis of three assumptions. Consequently, a new mathematical model was built to present the liquid flow inside the coke bed in a blast furnace. The mathematical model can predict the distribution of liquid flowrate and the liquid flowing range inside the packed bed at any time. The predicted results of this model accord well with the experimental data. The model will be applied considerably better in the simulation on the ironmaking process compared with the existent models. 展开更多
关键词 ironmaking process blast furnace packed bed discrete flow mathematical model
下载PDF
Design and Implementation of Visualized Workflow Modeling System Based on B/S Structure 被引量:2
11
作者 王坚 李巍丽 《Journal of Donghua University(English Edition)》 EI CAS 2007年第1期75-78,共4页
According to the necessity of flexible workflow management system, the solution to set up the visualized workflow modelling system based on B/S structure is put forward, which conforms to the relevant specifications o... According to the necessity of flexible workflow management system, the solution to set up the visualized workflow modelling system based on B/S structure is put forward, which conforms to the relevant specifications of WfMC and the workflow process definition meta-model. The design for system structure is presented in detail, and the key technologies for system implementation are also introduced. Additionally, an example is illustrated to demonstrate the validity of system. 展开更多
关键词 work flow work flow modeling system XPDL parsing.
下载PDF
Sedimentary Microfacies and Porosity Modeling of Deep-Water Sandy Debris Flows by Combining Sedimentary Patterns with Seismic Data: An Example from Unit I of Gas Field A, South China Sea 被引量:1
12
作者 LI Shengli YU Xinghe JIN Jianli 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2016年第1期182-194,共13页
Sandy debris flow deposits are present in Unit I during Miocene of Gas Field A in the Baiyun Depression of the South China Sea. The paucity of well data and the great variability of the sedimentary microfacies make it... Sandy debris flow deposits are present in Unit I during Miocene of Gas Field A in the Baiyun Depression of the South China Sea. The paucity of well data and the great variability of the sedimentary microfacies make it difficult to identify and predict the distribution patterns of the main gas reservoir, and have seriously hindered further exploration and development of the gas field. Therefore, making full use of the available seismic data is extremely important for predicting the spatial distribution of sedimentary microfacies when constructing three-dimensional reservoir models. A suitable reservoir modeling strategy or workflow controlled by sedimentary microfacies and seismic data has been developed. Five types of seismic attributes were selected to correlate with the sand percentage, and the root mean square (RMS) amplitude performed the best. The relation between the RMS amplitude and the sand percentage was used to construct a reservoir sand distribution map. Three types of main sedimentary microfacies were identified: debris channels, fan lobes, and natural levees. Using constraints from the sedimentary microfacies boundaries, a sedimentary microfacies model was constructed using the sequential indicator and assigned value simulation methods. Finally, reservoir models of physical properties for sandy debris flow deposits controlled by sedimentary microfacies and seismic inversion data were established. Property cutoff values were adopted because the sedimentary microfacies and the reservoir properties from well-logging interpretation are intrinsically different. Selection of appropriate reservoir property cutoffs is a key step in reservoir modeling when using simulation methods based on sedimentary microfacies control. When the abnormal data are truncated and the reservoir properties probability distribution fits a normal distribution, microfacies-controlled reservoir property models are more reliable than those obtained from the sequence Gauss simulation method. The cutoffs for effective porosity of the debris channel, fan lobe, and natural levee facies were 0.2, 0.09, and 0.12, respectively; the corresponding average effective porosities were 0.24, 0.13, and 0.15. The proposed modeling method makes full use of seismic attributes and seismic inversion data, and also makes the property data of single-well depositional microfacies more conformable to a normal distribution with geological significance. Thus, the method allows use of more reliable input data when we construct a model of a sandy debris flow. 展开更多
关键词 sandy debris flow deposit seismic attribute and inversion geological modeling controlled by micro-facies data truncated process
下载PDF
Pressure stimulated current in progressive failure process of combined coal-rock under uniaxial compression:Response and mechanism
13
作者 Tiancheng Shan Zhonghui Li +7 位作者 Xin Zhang Haishan Jia Xiaoran Wang Enyuan Wang Yue Niu Dong Chen Weichen Sun Dongming Wang 《International Journal of Mining Science and Technology》 SCIE EI CAS CSCD 2024年第2期227-243,共17页
Effective monitoring of the structural health of combined coal-rock under complex geological conditions by pressure stimulated currents(PSCs)has great potential for the understanding of dynamic disasters in undergroun... Effective monitoring of the structural health of combined coal-rock under complex geological conditions by pressure stimulated currents(PSCs)has great potential for the understanding of dynamic disasters in underground engineering.To reveal the effect of this way,the uniaxial compression experiments with PSC monitoring were conducted on three types of coal-rock combination samples with different strength combinations.The mechanism explanation of PSCs are investigated by resistivity test,atomic force microscopy(AFM)and computed tomography(CT)methods,and a PSC flow model based on progressive failure process is proposed.The influence of strength combinations on PSCs in the progressive failure process are emphasized.The results show the PSC responses between rock part,coal part and the two components are different,which are affected by multi-scale fracture characteristics and electrical properties.As the rock strength decreases,the progressive failure process changes obviously with the influence range of interface constraint effect decreasing,resulting in the different responses of PSC strength and direction in different parts to fracture behaviors.The PSC flow model is initially validated by the relationship between the accumulated charges of different parts.The results are expected to provide a new reference and method for mining design and roadway quality assessment. 展开更多
关键词 Combined coal-rock Pressure stimulated current Progressive failure process MECHANISM flow model
下载PDF
3D Model Reconstruction Based on Process Information 被引量:1
14
作者 SHI Yun-fei ZHANG Shu-sheng CAO Ju-lu FAN Hai-tao YANG Yan 《Computer Aided Drafting,Design and Manufacturing》 2007年第2期15-22,共8页
The traditional strategy of 3D model reconstruction mainly concentrates on orthographic projections or engineering drawings. But there are some shortcomings. Such as, only few kinds of solids can be reconstructed, the... The traditional strategy of 3D model reconstruction mainly concentrates on orthographic projections or engineering drawings. But there are some shortcomings. Such as, only few kinds of solids can be reconstructed, the high complexity of time and less information about the 3D model. The research is extended and process card is treated as part of the 3D reconstruction. A set of process data is a superset of 2D engineering drawings set. The set comprises process drawings and process steps, and shows a sequencing and asymptotic course that a part is made from roughcast blank to final product. According to these characteristics, the object to be reconstructed is translated from the complicated engineering drawings into a series of much simpler process drawings. With the plentiful process information added for reconstruction, the disturbances such as irrelevant graph, symbol and label, etc. can be avoided. And more, the form change of both neighbor process drawings is so little that the engineering drawings interpretation has no difficulty; in addition, the abnormal solution and multi-solution can be avoided during reconstruction, and the problems of being applicable to more objects is solved ultimately. Therefore, the utility method for 3D reconstruction model will be possible. On the other hand, the feature information in process cards is provided for reconstruction model. Focusing on process cards, the feasibility and requirements of Working Procedure Model reconstruction is analyzed, and the method to apply and implement the Natural Language Understanding into the 3D reconstruction is studied. The method of asymptotic approximation product was proposed, by which a 3D process model can be constructed automatically and intelligently. The process model not only includes the information about parts characters, but also can deliver the information of design, process and engineering to the downstream applications. 展开更多
关键词 3D model reconstruction natural language understanding process cards working procedure model feature model
下载PDF
Comparison on Mathematical Models for Description of Flow Curves of Stable Austenitic Steels
15
作者 Xing TIAN and Rujin TIANDepartment of Materials Science & Engineering, Dalian Railway Institute, Dalian 116028, China 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2003年第1期84-86,共3页
The flow curves were measured for the stable austenitic steels 304L and 304LN by means of tensile test at room temperature,which are described by the models σ=K1εn1 + exp(K2 + n2ε), σ=Kεn1+n2lnε and σ=σ0+Kεn ... The flow curves were measured for the stable austenitic steels 304L and 304LN by means of tensile test at room temperature,which are described by the models σ=K1εn1 + exp(K2 + n2ε), σ=Kεn1+n2lnε and σ=σ0+Kεn (where, K1, K2, n1 andn2; K, n1 and n2; σ0, K and n are constant). The comparison of the maximum deviations and the consideration of thevariation of the work hardening rate with true strain show that the flow curves for the austenitic steels 304L and 304LN canbe described by the model σ=Kεn1+n2 lnε at higher precision.The derivatives of the models σ=K1εn1 + exp(K2 + n2ε) and σ=Kεn1+n2lnε with respect to true strain, exhibit theextreme at low true strain. This inherent character indicates that both models are unsuitable to describe the part of the workhardening rate curve at low true strain. 展开更多
关键词 flow curve Mathematical model Work hardening rate
下载PDF
FLOW STRESS MODEL FOR HARD MACHINING OF AISI H13 WORK TOOL STEEL
16
作者 H. Yan J. Hua R. Shivpuri 《Acta Metallurgica Sinica(English Letters)》 SCIE EI CAS CSCD 2005年第6期741-748,共8页
An approach is presented to characterize the stress response of workpiece in hard machining, accounted for the effect of the initial workpiece hardness, temperature, strain and strain rate on flow stress. AISI H13 wor... An approach is presented to characterize the stress response of workpiece in hard machining, accounted for the effect of the initial workpiece hardness, temperature, strain and strain rate on flow stress. AISI H13 work tool steel was chosen to verify this methodology. The proposed flow stress model demonstrates a good agreement with data collected from published experiments. Therefore, the proposed model can be used to predict the corresponding flow stress-strain response of AISI H13 work tool steel with variation of the initial workpiece hardness in hard machining. 展开更多
关键词 flow stress model hard machining AISI H13 work tool steel
下载PDF
NUMERICAL CALCULATIONS OF GASEOUS REACTING FLOWS IN A MODEL OF GAS TURBINE COMBUSTORS
17
作者 Yan Chuanjun, Tang Ming, Zhu Huiling and Sun HuixianNorthwestern Polytechnical University 《Chinese Journal of Aeronautics》 SCIE EI CAS CSCD 1991年第1期26-34,共9页
This paper describes the numerical calculations of gaseous reaction flows in a model of gas turbine combustors. The profiles of hydrodynamic and thermodynamic patterns in a three-dimensional combustor model are obtain... This paper describes the numerical calculations of gaseous reaction flows in a model of gas turbine combustors. The profiles of hydrodynamic and thermodynamic patterns in a three-dimensional combustor model are obtained by solving the governing differential transport equations. The well-established numerical prediction algorithm SIMPLE, the modified k-ε turbulence model and k-ε-g turbulent diffusion flame model have been adopted in computations. The β function has been selected as probability density function. The effect of combustion process on flow patterns has been investigated. The calculated results have been verified by experiments. They are in remarkably good agreement. 展开更多
关键词 NUMERICAL CALCULATIONS OF GASEOUS REACTING flowS IN A model OF GAS TURBINE COMBUSTORS GAS flow WORK
下载PDF
COUPLING MODEL OF TWO PHASE FLOW IN A FRACTURE-ROCK MATRIX SYSTEM AND ITS STOCHASTIC FEATURE ANALYSIS
18
作者 王经明 李竞生 +1 位作者 高智联 杨保禹 《Journal of Coal Science & Engineering(China)》 1998年第1期5-10,共6页
This study is concerned with developing a two-dimensional two-phase model that simulate the movement of non-aqueous phase liquid (NAPL) in a fracture-rock matrix system. The intrinsic permeability and the fracture ape... This study is concerned with developing a two-dimensional two-phase model that simulate the movement of non-aqueous phase liquid (NAPL) in a fracture-rock matrix system. The intrinsic permeability and the fracture aperture are represented in the model via its KarhunenLoeve expansion. Other parameters and the nodal unknowns, water saturations and water pressures, are represented by their stochastic spectral expansions. The errors resulting from truncation of Karhunen - Loeve and polynomial chaos expansions to a finite number of terms are analyzed. The eigenvalues of stochastic process is found out for any point in the special domain of the problem at any instant in time. 展开更多
关键词 discrete dual medium TWO-PHASE flow coupling model stochastic process
下载PDF
基于Moldflow的制件注塑模设计与研究
19
作者 王宏强 石新霞 《山东工业技术》 2024年第5期74-81,共8页
利用Solidworks设计了一种简单的制件模型,基于此制件应用Moldflow进行了其成型所用模具工艺尺寸、浇注效果等的研究分析。通过分析研究,获取了XS-ZY-500型注射机为即定制件的成型设备;同时,得出制件成型压力为60-120 MPa,最大注射压力... 利用Solidworks设计了一种简单的制件模型,基于此制件应用Moldflow进行了其成型所用模具工艺尺寸、浇注效果等的研究分析。通过分析研究,获取了XS-ZY-500型注射机为即定制件的成型设备;同时,得出制件成型压力为60-120 MPa,最大注射压力在130-150 MPa,保压压力为注射压力的50%-80%;确定了最佳浇口位置,并计得出浇注完成时间为12.5 s;发现六水道冷却时冷却液分布较均匀合理可行,宜于制件的加工成型。本文的研究可以为注塑模设计分析提供一定的理论依据与参考,具有一定的工程意义。 展开更多
关键词 制件 注射模 成型工艺 模流分析
下载PDF
China's Uneven Labor Flow and Its Effect on Regional Disparities—Empirical analysis based on non-parameter additive model
20
作者 潘越 杜小敏 《China Economist》 2010年第6期102-111,共10页
This paper is the first to use a non-parameter additive model in the empirical analysis of the impact of cross-regional laborflow on industrialization and economic growth in China’s eastern,central and western region... This paper is the first to use a non-parameter additive model in the empirical analysis of the impact of cross-regional laborflow on industrialization and economic growth in China’s eastern,central and western regions.Results indicate that laborflow has significantly different effects on the direction and intensity of impact on economic development across regions:massive labor inflow from the central and western regions to the eastern region significantly promoted the industrializationprocess and economic growth in the East,while the impact of labor outflow from the central and western regions on theregional economies is in a significantly inverted-U shaped non-linear relationship.Uneven labor flow across regions haswidened China’s regional economic disparities. 展开更多
关键词 LABOR flow INDUSTRIALIZATION process ECONOMIC growth ADDITIVE model
全文增补中
上一页 1 2 43 下一页 到第
使用帮助 返回顶部