[Objective] The aim was to modify the application amount of N,P and K fertilizer so as to provide a reference for establishing balanced fertilization index system of banana.[Method]The N,P and K fertilizer ＂3414＂ te...[Objective] The aim was to modify the application amount of N,P and K fertilizer so as to provide a reference for establishing balanced fertilization index system of banana.[Method]The N,P and K fertilizer ＂3414＂ test was carried out on banana,and then regression analysis was performed on the fertilizer effect.Ternary quadratic,binary quadric and one-variable quadratic regression equations for the fertilizer effect on the banana yield were constructed.[Result]Suitable amount of N,P and K fertilizer had significant yield improving effect,whereas overdose of fertilizer application led to decreasing of utilization rate of fertilizer.Therefore,suitable amount of N,P and K fertilizer should be selected in production.It could be concluded that one-variable quadratic regression equations was the best model to calculate the suitable fertilizer amount.The best yield range of banana in the tested field was 44.193-45.904 t/hm2,while the corresponding optimum application amount of N,P2O5 and K2O was 795.1,262.3 and 1 236.9 kg/hm2 respectively,and the ratio among nitrogen,phosphorus and potassium are 1∶0.33∶1.55.[Conclusion]The result in this study could provide references for the soil types similar to the tested field.展开更多
Grinding is one of the most widely used material removal methods at the end of many process chains.Grinding force is related to almost all grinding parameters,which has a great influence on material removal rate,dimen...Grinding is one of the most widely used material removal methods at the end of many process chains.Grinding force is related to almost all grinding parameters,which has a great influence on material removal rate,dimensional and shape accuracy,surface and subsurface integrity,thermodynamics,dynamics,wheel durability,and machining system deformation.Considering that grinding force is related to almost all grinding parameters,grinding force can be used to detect grinding wheel wear,energy calculation,chatter suppression,force control and grinding process simulation.Accurate prediction of grinding forces is important for optimizing grinding parameters and the structure of grinding machines and fixtures.Although there are substantial research papers on grinding mechanics,a comprehensive review on the modeling of grinding mechanics is still absent from the literature.To fill this gap,this work reviews and introduces theoretical methods and applications of mechanics in grinding from the aspects of modeling principles,limitations and possible future trendencies.展开更多
The Forest Landscape Model （FLM） is an efficiency tool of quantified expression of forest ecosystem＇s structure and function. This paper, on the basis of identifying FLM, according to the stage of development, summ...The Forest Landscape Model （FLM） is an efficiency tool of quantified expression of forest ecosystem＇s structure and function. This paper, on the basis of identifying FLM, according to the stage of development, summarizes the development characteristics of the model, which includes the theoretical foundation of mathematical model, FLM of stand-scale, primary development of spatial landscape model, rapid development of ecosystem process model as the priority, and developing period of structure and process driven by multi-factor. According to the characteristics of different FLMs, this paper classifies the existing FLM in terms of mechanism, property and application, and elaborates the identifications, advantages and disadvantages of different types of models. It summarizes and evaluates the main ap- plication fields of existing models from two aspects which are the changes of spatial pattern and ecological process. Eventually, this paper presents FLM＇s challenges and directions of development in the future, including： （1） more prominent service on the practical strategy of forest management＇s objectives; （2） construction of multi-modules and multi-plugin to satisfy landscape research demand in various conditions; （3） adoption of high resolution＇s spatial-temporal data; （4） structural construction of multi-version module; （5） improving the spatial suitability of model application.展开更多
Energy structure is a complicated system concerning economic development, natural resources, technological innovation, ecological balance, social progress and many other elements. It is not easy to explain clearly the...Energy structure is a complicated system concerning economic development, natural resources, technological innovation, ecological balance, social progress and many other elements. It is not easy to explain clearly the developmental mechanism of an energy system and the mutual relations between the energy system and its related environments by the traditional methods. It is necessary to develop a suitable dynamic model, which can reflect the dynamic characteristics and the mutual relations of the energy system and its related environments. In this paper, the historical development of China＇s energy structure was analyzed. A new quantitative analysis model was developed based on system dynamics principles through analysis of energy resources, and the production and consumption of energy in China and comparison with the world. Finally, this model was used to predict China＇s future energy structures under different conditions.展开更多
The paper studied the connection between internet of things （lOT） technology and transportation industry. Meanwhile, the definition of IOT in transportation was given. Concerning that many problems occurred during t...The paper studied the connection between internet of things （lOT） technology and transportation industry. Meanwhile, the definition of IOT in transportation was given. Concerning that many problems occurred during the process of traditional intelligent transportation system, the paper proposed a promising model of lOT in transportation. The advantage of the information utilization model from information to function was confirmed through comparative study. Finally, the model presented that a real interconnection of transportation would be achieved based on the unified information collection. It can greatly save cost on technology transfer, exploit potential value of information, and promote the emergence of a sustainable information service market and the industrial upgrade.展开更多
In recent years, global reanalysis weather data has been widely used in hydrological modeling around the world, but the results of simulations vary greatly. To consider the applicability of Climate Forecast System Rea...In recent years, global reanalysis weather data has been widely used in hydrological modeling around the world, but the results of simulations vary greatly. To consider the applicability of Climate Forecast System Reanalysis（CFSR） data in the hydrologic simulation of watersheds, the Bahe River Basin was used as a case study. Two types of weather data（conventional weather data and CFSR weather data） were considered to establish a Soil and Water Assessment Tool（SWAT） model, which was used to simulate runoff from 2001 to 2012 in the basin at annual and monthly scales. The effect of both datasets on the simulation was assessed using regression analysis, Nash-Sutcliffe Efficiency（NSE）, and Percent Bias（PBIAS）. A CFSR weather data correction method was proposed. The main results were as follows.（1） The CFSR climate data was applicable for hydrologic simulation in the Bahe River Basin（R^2 of the simulated results above 0.50, NSE above 0.33, and ｜PBIAS｜ below 14.8. Although the quality of the CFSR weather data is not perfect, it achieved a satisfactory hydrological simulation after rainfall data correction.（2） The simulated streamflow using the CFSR data was higher than the observed streamflow, which was likely because the estimation of daily rainfall data by CFSR weather data resulted in more rainy days and stronger rainfall intensity than was actually observed. Therefore, the data simulated a higher base flow and flood peak discharge in terms of the water balance, except for some individual years.（3） The relation between the CFSR rainfall data（x） and the observed rainfall data（y） could berepresented by a power exponent equation： y=1.4789x0.8875（R2=0.98,P〈0.001）. There was a slight variation between the fitted equations for each station. The equation provides a theoretical basis for the correction of CFSR rainfall data.展开更多
We present an efficient three-dimensional coupled-mode model based on the Fourier synthesis technique. In principle, this model is a one-way model, and hence provides satisfactory accuracy for problems where the forwa...We present an efficient three-dimensional coupled-mode model based on the Fourier synthesis technique. In principle, this model is a one-way model, and hence provides satisfactory accuracy for problems where the forward scattering dominates. At the same time, this model provides an efficiency gain of an order of magnitude or more over two-way coupled-mode models. This model can be applied to three-dimensional range-dependent problems with a slowly varying bathymetry or internal waves. A numerical example of the latter is demonstrated in this work. Comparisons of both accuracy and efficiency between the present model and a benchmark model are also provided.展开更多
The Chang-63 reservoir in the Huaqing area has widely developed tight sandstone ＂thick sand layers, but not reservoirs characterized by rich in oil＂, and it is thus necessary to further study its oil and gas enrichm...The Chang-63 reservoir in the Huaqing area has widely developed tight sandstone ＂thick sand layers, but not reservoirs characterized by rich in oil＂, and it is thus necessary to further study its oil and gas enrichment law. This study builds porosity and fracture development and evolution models in different deposition environments, through core observation, casting thin section, SEM, porosity and permeability analysis, burial history analysis, and ＂four-property-relationships＂ analysis.展开更多
Regional climate models have become the powerful tools for simulating regional climate and its change process and have been widely used in China. Using regional climate models, some research results have been obtained...Regional climate models have become the powerful tools for simulating regional climate and its change process and have been widely used in China. Using regional climate models, some research results have been obtained on the following aspects： 1） the numerical simulation of East Asian monsoon climate, including exceptional monsoon precipitation, summer precipitation distribution, East Asian circulation, multi-year climate average condition, summer rain belt and so on; 2） the simulation of arid climate of the western China, including thermal effect of the Qinghal-Tibet Plateau, the plateau precipitation in the Qilian Mountains; and the impacts of greenhouse effects （CO2 doubling） upon climate in the western China; and 3） the simulation of the climate effect of underlying surface changes, including the effect of soil on climate formation, the influence of terrain on precipitation, the effect of regional soil degradation on regional climate, the effect of various underlying surfaces on regional climate, the effect of land-sea contrast on the climate formulation, the influence of snow cover over the plateau regions on the regional climate, the effect of vegetation changes on the regional climate, etc. In the process of application of regional climate models, the preferences of the models are improved so that better simulation results are gotten. At last, some suggestions are made about the application of regional climate models in regional climate research in the future.展开更多
Fixture design and planning is one of the most important manufacturing activities, playing a pivotal role in deciding the lead time for product development. Fixture design, which affects the part-quality in terms of g...Fixture design and planning is one of the most important manufacturing activities, playing a pivotal role in deciding the lead time for product development. Fixture design, which affects the part-quality in terms of geometric accuracy and surface finish, can be enhanced by using the product manufacturing information(PMI) stored in the neutral standard for the exchange of product model data(STEP) file, thereby integrating design and manufacturing. The present paper proposes a unique fixture design approach, to extract the geometry information from STEP application protocol(AP) 242 files of computer aided design(CAD) models, for providing automatic suggestions of locator positions and clamping surfaces. Automatic feature extraction software "FiXplan", developed using the programming language C#, is used to extract the part feature, dimension and geometry information. The information from the STEP AP 242 file is deduced using geometric reasoning techniques, which in turn is utilized for fixture planning. The developed software is observed to be adept in identifying the primary, secondary, and tertiary locating faces and locator position configurations of prismatic components. Structural analysis of the prismatic part under different locator positions was performed using commercial finite element method software, ABAQUS, and the optimized locator position was identified on the basis of minimum deformation of the workpiece.The area-ratio(base locator enclosed area(%)/work piece base area(%)) for the ideal locator configuration was observed as 33%. Experiments were conducted on a prismatic workpiece using a specially designed fixture, for different locator configurations. The surface roughness and waviness of the machined surfaces were analysed using an Alicona non-contact optical profilometer. The best surface characteristics were obtained for the surface machined under the ideal locator positions having an area-ratio of 33%, thus validating the predicted numerical results. The efficiency, capability and applicability of the developed software is demonstrated for the finishing operation of a sensor cover – a typical prismatic component having applications in the naval industry, under different locator configurations.The best results were obtained under the proposed ideal locator configuration of area-ratio 33%.展开更多
Ireproving the quality and experience perceived by the user is fundamental when de- veloping multimedia technologies, products, and services. Quality of experience （QoE） involves subjective perception, user behavior...Ireproving the quality and experience perceived by the user is fundamental when de- veloping multimedia technologies, products, and services. Quality of experience （QoE） involves subjective perception, user behavior and needs, appropriateness, con- text, and usability of delivered content. Modeling QoE is critical for enhancing QoE in various nmhimedia applications. In this special issue,展开更多
The modified shear lag model proposed recently was applied to calculate thermal residual stresses and subsequent stress distributions under tensile and compressive loadings. The expressions for the elastic moduli and ...The modified shear lag model proposed recently was applied to calculate thermal residual stresses and subsequent stress distributions under tensile and compressive loadings. The expressions for the elastic moduli and the yield strengths under tensile and compressive loadings were derived which take account of thermal residual stresses. The asymmetries in the elastic modulus and the yield strength were interpreted using the derived expressions and the obtained results of the stress calculations. The model predictions have exhibited good agreements with the experimental results and also with the other theoretical predictions展开更多
Method of VSC (Voltage Shorted Compaction)can be used to determine the intrinsic temperature dependence ofconductivity ofpolycrystalline compaction. The experimental conditions and technical key for preparation of VSC...Method of VSC (Voltage Shorted Compaction)can be used to determine the intrinsic temperature dependence ofconductivity ofpolycrystalline compaction. The experimental conditions and technical key for preparation of VSC device and its physical model as well as its applications in conducting polymers are discussed in detail.展开更多
An enzyme is a kind of protein with catalytic activity and long chain,and its structure and shape are determined by the hybridized state of atomic orbital.The fractal dimension(D_f)is closely related to the hybridizat...An enzyme is a kind of protein with catalytic activity and long chain,and its structure and shape are determined by the hybridized state of atomic orbital.The fractal dimension(D_f)is closely related to the hybridization,e.g.D_f=2ln2/ln[2(1+α/(1-α))]for the spa type, where a denotes the fraction of the s orbital in the hybridized molecular orbital.This relationship and the five fractal theorems introduced by the present paper play an important role in the investigations of the model of imitative enzyme.展开更多
This paper discusses the Rb-Sr geochemical behaviour of illites in the sedimentary process, and points out that illites of the lmd and lm types could reach Sr-isotopic equilibrium with its environmental medium during ...This paper discusses the Rb-Sr geochemical behaviour of illites in the sedimentary process, and points out that illites of the lmd and lm types could reach Sr-isotopic equilibrium with its environmental medium during the sedimentary process and initial stage of diagenesis, and illite grains of different sizes have various Rb contents. A new dating method for sedimentary rocks----a dating model of illite grain Rb-Sr isochron----is established, in consideration of the geochemical process of Sr-isotopic homogenization and differentiation in the course of their formation and evolution. In addition, the paper concerns the application of the dating model to the Precambrian unmetamorphosed sedimentary rocks in western Henan Province, which gives satisfactory results coincident with the geological facts.展开更多
Coulomb stress changes associated with strong earthquakes occurring since 1484 in Hebei Province,China are investigated. The North China block has had many large historical earthquakes and some damaging earthquakes in...Coulomb stress changes associated with strong earthquakes occurring since 1484 in Hebei Province,China are investigated. The North China block has had many large historical earthquakes and some damaging earthquakes in the past century,including the 1976 Tangshan earthquake (M =7.8) . The study area and the adjacent areas of the province comprise the most active seismic fault zones and suffer from both strong and frequent events. The North China Block,which includes the Ordos plateau and the North China plain,is part of the Archean Sino-Lorean craton and one of the most active seismic regions in the world. Its movement is accommodated on major strike-slip intraplate fault zones that strike in the E-W direction. The faults in the study area contribute to the complexity of the stress field. Seismic hazard assessment in this region is attempted by calculating the change of the Coulomb failure function ( ΔCFF) arising from both the coseismic slip of strong events (MS≥6.5) and the stress built up by continuous tectonic loading on major regional faults. At every step of the stress evolutionary model an examination of possible triggering of each next strong event is made and the model finally puts in evidence that the fault segments that are apt to fail in an impending strong event,thus providing future seismic hazard evaluation. In this paper,the results of ΔCFF for Zhangjiakou fault, Xiadian fault and Langfang fault have been shown as examples to express the possiblity of generating future seismic hazard.展开更多
基金Supported by National Science and Technology Support Program(2007BAD89B14)Science and Technology Project of Guangdong Province(2009B020201011)~~
文摘[Objective] The aim was to modify the application amount of N,P and K fertilizer so as to provide a reference for establishing balanced fertilization index system of banana.[Method]The N,P and K fertilizer ＂3414＂ test was carried out on banana,and then regression analysis was performed on the fertilizer effect.Ternary quadratic,binary quadric and one-variable quadratic regression equations for the fertilizer effect on the banana yield were constructed.[Result]Suitable amount of N,P and K fertilizer had significant yield improving effect,whereas overdose of fertilizer application led to decreasing of utilization rate of fertilizer.Therefore,suitable amount of N,P and K fertilizer should be selected in production.It could be concluded that one-variable quadratic regression equations was the best model to calculate the suitable fertilizer amount.The best yield range of banana in the tested field was 44.193-45.904 t/hm2,while the corresponding optimum application amount of N,P2O5 and K2O was 795.1,262.3 and 1 236.9 kg/hm2 respectively,and the ratio among nitrogen,phosphorus and potassium are 1∶0.33∶1.55.[Conclusion]The result in this study could provide references for the soil types similar to the tested field.
基金co-supported by the Enterprise Innovation and Development Joint Program of the National Natural Science Foundation of China (No. U20B2032)National Natural Science Foundation of China (No. 51875135)
文摘Grinding is one of the most widely used material removal methods at the end of many process chains.Grinding force is related to almost all grinding parameters,which has a great influence on material removal rate,dimensional and shape accuracy,surface and subsurface integrity,thermodynamics,dynamics,wheel durability,and machining system deformation.Considering that grinding force is related to almost all grinding parameters,grinding force can be used to detect grinding wheel wear,energy calculation,chatter suppression,force control and grinding process simulation.Accurate prediction of grinding forces is important for optimizing grinding parameters and the structure of grinding machines and fixtures.Although there are substantial research papers on grinding mechanics,a comprehensive review on the modeling of grinding mechanics is still absent from the literature.To fill this gap,this work reviews and introduces theoretical methods and applications of mechanics in grinding from the aspects of modeling principles,limitations and possible future trendencies.
基金The National Basic Research Program of China （973 Program）, No.2015CB452702 No.2012CB416906+1 种基金 National Key Technology R＆D Program, No.2013BAC03B04 National Natural Science Foundation of China, No.41371196
文摘The Forest Landscape Model （FLM） is an efficiency tool of quantified expression of forest ecosystem＇s structure and function. This paper, on the basis of identifying FLM, according to the stage of development, summarizes the development characteristics of the model, which includes the theoretical foundation of mathematical model, FLM of stand-scale, primary development of spatial landscape model, rapid development of ecosystem process model as the priority, and developing period of structure and process driven by multi-factor. According to the characteristics of different FLMs, this paper classifies the existing FLM in terms of mechanism, property and application, and elaborates the identifications, advantages and disadvantages of different types of models. It summarizes and evaluates the main ap- plication fields of existing models from two aspects which are the changes of spatial pattern and ecological process. Eventually, this paper presents FLM＇s challenges and directions of development in the future, including： （1） more prominent service on the practical strategy of forest management＇s objectives; （2） construction of multi-modules and multi-plugin to satisfy landscape research demand in various conditions; （3） adoption of high resolution＇s spatial-temporal data; （4） structural construction of multi-version module; （5） improving the spatial suitability of model application.
文摘Energy structure is a complicated system concerning economic development, natural resources, technological innovation, ecological balance, social progress and many other elements. It is not easy to explain clearly the developmental mechanism of an energy system and the mutual relations between the energy system and its related environments by the traditional methods. It is necessary to develop a suitable dynamic model, which can reflect the dynamic characteristics and the mutual relations of the energy system and its related environments. In this paper, the historical development of China＇s energy structure was analyzed. A new quantitative analysis model was developed based on system dynamics principles through analysis of energy resources, and the production and consumption of energy in China and comparison with the world. Finally, this model was used to predict China＇s future energy structures under different conditions.
基金CAE Internet of Things and its Application Project in 2010National Basic Research Program of China"973"Program (No. 2012CB315805)
文摘The paper studied the connection between internet of things （lOT） technology and transportation industry. Meanwhile, the definition of IOT in transportation was given. Concerning that many problems occurred during the process of traditional intelligent transportation system, the paper proposed a promising model of lOT in transportation. The advantage of the information utilization model from information to function was confirmed through comparative study. Finally, the model presented that a real interconnection of transportation would be achieved based on the unified information collection. It can greatly save cost on technology transfer, exploit potential value of information, and promote the emergence of a sustainable information service market and the industrial upgrade.
基金International Partnership Program of Chinese Academy of Sciences,No.131551KYSB20160002 National Natural Science Foundation of China,No.41401602+2 种基金 Natural Science Basic Research Plan in Shaanxi Province of China,No.2014JQ2-4021 Key Scientific and Technological Innovation Team Plan of Shaanxi Province,No.2014KCT-27 Graduate Student Innovation Project of Northwest University,No.YZZ15011
文摘In recent years, global reanalysis weather data has been widely used in hydrological modeling around the world, but the results of simulations vary greatly. To consider the applicability of Climate Forecast System Reanalysis（CFSR） data in the hydrologic simulation of watersheds, the Bahe River Basin was used as a case study. Two types of weather data（conventional weather data and CFSR weather data） were considered to establish a Soil and Water Assessment Tool（SWAT） model, which was used to simulate runoff from 2001 to 2012 in the basin at annual and monthly scales. The effect of both datasets on the simulation was assessed using regression analysis, Nash-Sutcliffe Efficiency（NSE）, and Percent Bias（PBIAS）. A CFSR weather data correction method was proposed. The main results were as follows.（1） The CFSR climate data was applicable for hydrologic simulation in the Bahe River Basin（R^2 of the simulated results above 0.50, NSE above 0.33, and ｜PBIAS｜ below 14.8. Although the quality of the CFSR weather data is not perfect, it achieved a satisfactory hydrological simulation after rainfall data correction.（2） The simulated streamflow using the CFSR data was higher than the observed streamflow, which was likely because the estimation of daily rainfall data by CFSR weather data resulted in more rainy days and stronger rainfall intensity than was actually observed. Therefore, the data simulated a higher base flow and flood peak discharge in terms of the water balance, except for some individual years.（3） The relation between the CFSR rainfall data（x） and the observed rainfall data（y） could berepresented by a power exponent equation： y=1.4789x0.8875（R2=0.98,P〈0.001）. There was a slight variation between the fitted equations for each station. The equation provides a theoretical basis for the correction of CFSR rainfall data.
基金Supported by the National Natural Science Foundation of China under Grant No 11774374the Natural Science Foundation of Shandong Province of China under Grant No ZR2016AL10
文摘We present an efficient three-dimensional coupled-mode model based on the Fourier synthesis technique. In principle, this model is a one-way model, and hence provides satisfactory accuracy for problems where the forward scattering dominates. At the same time, this model provides an efficiency gain of an order of magnitude or more over two-way coupled-mode models. This model can be applied to three-dimensional range-dependent problems with a slowly varying bathymetry or internal waves. A numerical example of the latter is demonstrated in this work. Comparisons of both accuracy and efficiency between the present model and a benchmark model are also provided.
文摘The Chang-63 reservoir in the Huaqing area has widely developed tight sandstone ＂thick sand layers, but not reservoirs characterized by rich in oil＂, and it is thus necessary to further study its oil and gas enrichment law. This study builds porosity and fracture development and evolution models in different deposition environments, through core observation, casting thin section, SEM, porosity and permeability analysis, burial history analysis, and ＂four-property-relationships＂ analysis.
基金Under the auspices of National Natural Science Foundation of China (No. 40771190)Foundation of Research Start-upfor Winner of President Scholarship of Chinese Academy of Sciences (No. C08B9)Foundation of Key Laboratory of Wetland Ecology and Environment, Chinese Academy of Sciences (No. WELF-2004-B-001)
文摘Regional climate models have become the powerful tools for simulating regional climate and its change process and have been widely used in China. Using regional climate models, some research results have been obtained on the following aspects： 1） the numerical simulation of East Asian monsoon climate, including exceptional monsoon precipitation, summer precipitation distribution, East Asian circulation, multi-year climate average condition, summer rain belt and so on; 2） the simulation of arid climate of the western China, including thermal effect of the Qinghal-Tibet Plateau, the plateau precipitation in the Qilian Mountains; and the impacts of greenhouse effects （CO2 doubling） upon climate in the western China; and 3） the simulation of the climate effect of underlying surface changes, including the effect of soil on climate formation, the influence of terrain on precipitation, the effect of regional soil degradation on regional climate, the effect of various underlying surfaces on regional climate, the effect of land-sea contrast on the climate formulation, the influence of snow cover over the plateau regions on the regional climate, the effect of vegetation changes on the regional climate, etc. In the process of application of regional climate models, the preferences of the models are improved so that better simulation results are gotten. At last, some suggestions are made about the application of regional climate models in regional climate research in the future.
基金Department of Science and Technology,Government of India for providing financial support under the scheme FIST(No.SR/FST/ETI-388/2015)。
文摘Fixture design and planning is one of the most important manufacturing activities, playing a pivotal role in deciding the lead time for product development. Fixture design, which affects the part-quality in terms of geometric accuracy and surface finish, can be enhanced by using the product manufacturing information(PMI) stored in the neutral standard for the exchange of product model data(STEP) file, thereby integrating design and manufacturing. The present paper proposes a unique fixture design approach, to extract the geometry information from STEP application protocol(AP) 242 files of computer aided design(CAD) models, for providing automatic suggestions of locator positions and clamping surfaces. Automatic feature extraction software "FiXplan", developed using the programming language C#, is used to extract the part feature, dimension and geometry information. The information from the STEP AP 242 file is deduced using geometric reasoning techniques, which in turn is utilized for fixture planning. The developed software is observed to be adept in identifying the primary, secondary, and tertiary locating faces and locator position configurations of prismatic components. Structural analysis of the prismatic part under different locator positions was performed using commercial finite element method software, ABAQUS, and the optimized locator position was identified on the basis of minimum deformation of the workpiece.The area-ratio(base locator enclosed area(%)/work piece base area(%)) for the ideal locator configuration was observed as 33%. Experiments were conducted on a prismatic workpiece using a specially designed fixture, for different locator configurations. The surface roughness and waviness of the machined surfaces were analysed using an Alicona non-contact optical profilometer. The best surface characteristics were obtained for the surface machined under the ideal locator positions having an area-ratio of 33%, thus validating the predicted numerical results. The efficiency, capability and applicability of the developed software is demonstrated for the finishing operation of a sensor cover – a typical prismatic component having applications in the naval industry, under different locator configurations.The best results were obtained under the proposed ideal locator configuration of area-ratio 33%.
文摘Ireproving the quality and experience perceived by the user is fundamental when de- veloping multimedia technologies, products, and services. Quality of experience （QoE） involves subjective perception, user behavior and needs, appropriateness, con- text, and usability of delivered content. Modeling QoE is critical for enhancing QoE in various nmhimedia applications. In this special issue,
文摘The modified shear lag model proposed recently was applied to calculate thermal residual stresses and subsequent stress distributions under tensile and compressive loadings. The expressions for the elastic moduli and the yield strengths under tensile and compressive loadings were derived which take account of thermal residual stresses. The asymmetries in the elastic modulus and the yield strength were interpreted using the derived expressions and the obtained results of the stress calculations. The model predictions have exhibited good agreements with the experimental results and also with the other theoretical predictions
文摘Method of VSC (Voltage Shorted Compaction)can be used to determine the intrinsic temperature dependence ofconductivity ofpolycrystalline compaction. The experimental conditions and technical key for preparation of VSC device and its physical model as well as its applications in conducting polymers are discussed in detail.
文摘An enzyme is a kind of protein with catalytic activity and long chain,and its structure and shape are determined by the hybridized state of atomic orbital.The fractal dimension(D_f)is closely related to the hybridization,e.g.D_f=2ln2/ln[2(1+α/(1-α))]for the spa type, where a denotes the fraction of the s orbital in the hybridized molecular orbital.This relationship and the five fractal theorems introduced by the present paper play an important role in the investigations of the model of imitative enzyme.
基金This research was financially supported by the Academia Sinica Foundation
文摘This paper discusses the Rb-Sr geochemical behaviour of illites in the sedimentary process, and points out that illites of the lmd and lm types could reach Sr-isotopic equilibrium with its environmental medium during the sedimentary process and initial stage of diagenesis, and illite grains of different sizes have various Rb contents. A new dating method for sedimentary rocks----a dating model of illite grain Rb-Sr isochron----is established, in consideration of the geochemical process of Sr-isotopic homogenization and differentiation in the course of their formation and evolution. In addition, the paper concerns the application of the dating model to the Precambrian unmetamorphosed sedimentary rocks in western Henan Province, which gives satisfactory results coincident with the geological facts.
基金funded by the project of "Strong Motion Records in the Seismic Resistance of the Tangshan Region ( No. 11276905D) ",Department of Science and Technology of Hebei Province,China
文摘Coulomb stress changes associated with strong earthquakes occurring since 1484 in Hebei Province,China are investigated. The North China block has had many large historical earthquakes and some damaging earthquakes in the past century,including the 1976 Tangshan earthquake (M =7.8) . The study area and the adjacent areas of the province comprise the most active seismic fault zones and suffer from both strong and frequent events. The North China Block,which includes the Ordos plateau and the North China plain,is part of the Archean Sino-Lorean craton and one of the most active seismic regions in the world. Its movement is accommodated on major strike-slip intraplate fault zones that strike in the E-W direction. The faults in the study area contribute to the complexity of the stress field. Seismic hazard assessment in this region is attempted by calculating the change of the Coulomb failure function ( ΔCFF) arising from both the coseismic slip of strong events (MS≥6.5) and the stress built up by continuous tectonic loading on major regional faults. At every step of the stress evolutionary model an examination of possible triggering of each next strong event is made and the model finally puts in evidence that the fault segments that are apt to fail in an impending strong event,thus providing future seismic hazard evaluation. In this paper,the results of ΔCFF for Zhangjiakou fault, Xiadian fault and Langfang fault have been shown as examples to express the possiblity of generating future seismic hazard.
